libmicrohttpd

HTTP/1.x server C library (MHD 1.x, stable)
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microhttpd.h (257385B)


      1 /*
      2      This file is part of libmicrohttpd
      3      Copyright (C) 2006-2021 Christian Grothoff (and other contributing authors)
      4      Copyright (C) 2014-2023 Evgeny Grin (Karlson2k)
      5 
      6      This library is free software; you can redistribute it and/or
      7      modify it under the terms of the GNU Lesser General Public
      8      License as published by the Free Software Foundation; either
      9      version 2.1 of the License, or (at your option) any later version.
     10 
     11      This library is distributed in the hope that it will be useful,
     12      but WITHOUT ANY WARRANTY; without even the implied warranty of
     13      MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
     14      Lesser General Public License for more details.
     15 
     16      You should have received a copy of the GNU Lesser General Public
     17      License along with this library; if not, write to the Free Software
     18      Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
     19 */
     20 
     21 /**
     22  * @file microhttpd.h
     23  * @brief public interface to libmicrohttpd
     24  * @author Christian Grothoff
     25  * @author Karlson2k (Evgeny Grin)
     26  * @author Chris GauthierDickey
     27  *
     28  * All symbols defined in this header start with MHD.  MHD is a small
     29  * HTTP daemon library.  As such, it does not have any API for logging
     30  * errors (you can only enable or disable logging to stderr).  Also,
     31  * it may not support all of the HTTP features directly, where
     32  * applicable, portions of HTTP may have to be handled by clients of
     33  * the library.
     34  *
     35  * The library is supposed to handle everything that it must handle
     36  * (because the API would not allow clients to do this), such as basic
     37  * connection management; however, detailed interpretations of headers
     38  * -- such as range requests -- and HTTP methods are left to clients.
     39  * The library does understand HEAD and will only send the headers of
     40  * the response and not the body, even if the client supplied a body.
     41  * The library also understands headers that control connection
     42  * management (specifically, "Connection: close" and "Expect: 100
     43  * continue" are understood and handled automatically).
     44  *
     45  * MHD understands POST data and is able to decode certain formats
     46  * (at the moment only "application/x-www-form-urlencoded" and
     47  * "multipart/formdata"). Unsupported encodings and large POST
     48  * submissions may require the application to manually process
     49  * the stream, which is provided to the main application (and thus can be
     50  * processed, just not conveniently by MHD).
     51  *
     52  * The header file defines various constants used by the HTTP protocol.
     53  * This does not mean that MHD actually interprets all of these
     54  * values.  The provided constants are exported as a convenience
     55  * for users of the library.  MHD does not verify that transmitted
     56  * HTTP headers are part of the standard specification; users of the
     57  * library are free to define their own extensions of the HTTP
     58  * standard and use those with MHD.
     59  *
     60  * All functions are guaranteed to be completely reentrant and
     61  * thread-safe (with the exception of #MHD_set_connection_value,
     62  * which must only be used in a particular context).
     63  *
     64  *
     65  * @defgroup event event-loop control
     66  * MHD API to start and stop the HTTP server and manage the event loop.
     67  * @defgroup response generation of responses
     68  * MHD API used to generate responses.
     69  * @defgroup request handling of requests
     70  * MHD API used to access information about requests.
     71  * @defgroup authentication HTTP authentication
     72  * MHD API related to basic and digest HTTP authentication.
     73  * @defgroup logging logging
     74  * MHD API to manage logging and error handling
     75  * @defgroup specialized misc. specialized functions
     76  * This group includes functions that do not fit into any particular
     77  * category and that are rarely used.
     78  */
     79 
     80 #ifndef MHD_MICROHTTPD_H
     81 #define MHD_MICROHTTPD_H
     82 
     83 #ifndef __cplusplus
     84 #  define MHD_C_DECLRATIONS_START_HERE_   /* Empty */
     85 #  define MHD_C_DECLRATIONS_FINISH_HERE_  /* Empty */
     86 #else  /* __cplusplus */
     87 /* *INDENT-OFF* */
     88 #  define MHD_C_DECLRATIONS_START_HERE_   extern "C" {
     89 #  define MHD_C_DECLRATIONS_FINISH_HERE_  }
     90 /* *INDENT-ON* */
     91 #endif /* __cplusplus */
     92 
     93 
     94 MHD_C_DECLRATIONS_START_HERE_
     95 
     96 
     97 /**
     98  * Current version of the library in packed BCD form.
     99  * @note Version number components are coded as Simple Binary-Coded Decimal
    100  * (also called Natural BCD or BCD 8421). While they are hexadecimal numbers,
    101  * they are parsed as decimal numbers.
    102  * Example: 0x01093001 = 1.9.30-1.
    103  */
    104 #define MHD_VERSION 0x01000800
    105 
    106 /* If generic headers don't work on your platform, include headers
    107    which define 'va_list', 'size_t', 'ssize_t', 'intptr_t', 'off_t',
    108    'uint8_t', 'uint16_t', 'int32_t', 'uint32_t', 'int64_t', 'uint64_t',
    109    'struct sockaddr', 'socklen_t', 'fd_set' and "#define MHD_PLATFORM_H" before
    110    including "microhttpd.h". Then the following "standard"
    111    includes won't be used (which might be a good idea, especially
    112    on platforms where they do not exist).
    113    */
    114 #ifndef MHD_PLATFORM_H
    115 #if defined(_WIN32) && ! defined(__CYGWIN__) && \
    116   ! defined(_CRT_DECLARE_NONSTDC_NAMES)
    117 /* Declare POSIX-compatible names */
    118 #define _CRT_DECLARE_NONSTDC_NAMES 1
    119 #endif /* _WIN32 && ! __CYGWIN__ && ! _CRT_DECLARE_NONSTDC_NAMES */
    120 #include <stdarg.h>
    121 #include <stdint.h>
    122 #include <sys/types.h>
    123 #if ! defined(_WIN32) || defined(__CYGWIN__)
    124 #include <unistd.h>
    125 #include <sys/time.h>
    126 #include <sys/socket.h>
    127 #else  /* _WIN32 && ! __CYGWIN__ */
    128 #include <ws2tcpip.h>
    129 #if defined(_MSC_FULL_VER) && ! defined(_SSIZE_T_DEFINED)
    130 #define _SSIZE_T_DEFINED
    131 typedef intptr_t ssize_t;
    132 #endif /* !_SSIZE_T_DEFINED */
    133 #endif /* _WIN32 && ! __CYGWIN__ */
    134 #endif
    135 
    136 #if defined(__CYGWIN__) && ! defined(_SYS_TYPES_FD_SET)
    137 /* Do not define __USE_W32_SOCKETS under Cygwin! */
    138 #error Cygwin with winsock fd_set is not supported
    139 #endif
    140 
    141 #ifdef __has_attribute
    142 #if __has_attribute (flag_enum)
    143 #define _MHD_FLAGS_ENUM __attribute__((flag_enum))
    144 #endif /* flag_enum */
    145 #if __has_attribute (enum_extensibility)
    146 #define _MHD_FIXED_ENUM __attribute__((enum_extensibility (closed)))
    147 #endif /* enum_extensibility */
    148 #endif /* __has_attribute */
    149 
    150 #ifndef _MHD_FLAGS_ENUM
    151 #define _MHD_FLAGS_ENUM
    152 #endif /* _MHD_FLAGS_ENUM */
    153 #ifndef _MHD_FIXED_ENUM
    154 #define _MHD_FIXED_ENUM
    155 #endif /* _MHD_FIXED_ENUM */
    156 
    157 #define _MHD_FIXED_FLAGS_ENUM _MHD_FIXED_ENUM _MHD_FLAGS_ENUM
    158 
    159 /**
    160  * Operational results from MHD calls.
    161  */
    162 enum MHD_Result
    163 {
    164   /**
    165    * MHD result code for "NO".
    166    */
    167   MHD_NO = 0,
    168 
    169   /**
    170    * MHD result code for "YES".
    171    */
    172   MHD_YES = 1
    173 
    174 } _MHD_FIXED_ENUM;
    175 
    176 /**
    177  * Constant used to indicate unknown size (use when
    178  * creating a response).
    179  */
    180 #ifdef UINT64_MAX
    181 #define MHD_SIZE_UNKNOWN UINT64_MAX
    182 #else
    183 #define MHD_SIZE_UNKNOWN  ((uint64_t) -1LL)
    184 #endif
    185 
    186 #define MHD_CONTENT_READER_END_OF_STREAM ((ssize_t) -1)
    187 #define MHD_CONTENT_READER_END_WITH_ERROR ((ssize_t) -2)
    188 
    189 #ifndef _MHD_EXTERN
    190 #if defined(_WIN32) && defined(MHD_W32LIB)
    191 #define _MHD_EXTERN extern
    192 #elif defined(_WIN32) && defined(MHD_W32DLL)
    193 /* Define MHD_W32DLL when using MHD as W32 .DLL to speed up linker a little */
    194 #define _MHD_EXTERN __declspec(dllimport)
    195 #else
    196 #define _MHD_EXTERN extern
    197 #endif
    198 #endif
    199 
    200 #ifndef MHD_SOCKET_DEFINED
    201 /**
    202  * MHD_socket is type for socket FDs
    203  */
    204 #if ! defined(_WIN32) || defined(_SYS_TYPES_FD_SET)
    205 #define MHD_POSIX_SOCKETS 1
    206 typedef int MHD_socket;
    207 #define MHD_INVALID_SOCKET (-1)
    208 #else /* !defined(_WIN32) || defined(_SYS_TYPES_FD_SET) */
    209 #define MHD_WINSOCK_SOCKETS 1
    210 #include <winsock2.h>
    211 typedef SOCKET MHD_socket;
    212 #define MHD_INVALID_SOCKET (INVALID_SOCKET)
    213 #endif /* !defined(_WIN32) || defined(_SYS_TYPES_FD_SET) */
    214 #define MHD_SOCKET_DEFINED 1
    215 #endif /* MHD_SOCKET_DEFINED */
    216 
    217 /**
    218  * Define MHD_NO_DEPRECATION before including "microhttpd.h" to disable deprecation messages
    219  */
    220 #ifdef MHD_NO_DEPRECATION
    221 #define _MHD_DEPR_MACRO(msg)
    222 #define _MHD_NO_DEPR_IN_MACRO 1
    223 #define _MHD_DEPR_IN_MACRO(msg)
    224 #define _MHD_NO_DEPR_FUNC 1
    225 #define _MHD_DEPR_FUNC(msg)
    226 #endif /* MHD_NO_DEPRECATION */
    227 
    228 #ifndef _MHD_DEPR_MACRO
    229 #if defined(_MSC_FULL_VER) && _MSC_VER + 0 >= 1500
    230 /* VS 2008 or later */
    231 /* Stringify macros */
    232 #define _MHD_INSTRMACRO(a) #a
    233 #define _MHD_STRMACRO(a) _MHD_INSTRMACRO (a)
    234 /* deprecation message */
    235 #define _MHD_DEPR_MACRO(msg) \
    236         __pragma \
    237         (message (__FILE__ "(" _MHD_STRMACRO ( __LINE__) "): warning: " msg))
    238 #define _MHD_DEPR_IN_MACRO(msg) _MHD_DEPR_MACRO (msg)
    239 #elif defined(__clang__) || defined(__GNUC_PATCHLEVEL__)
    240 /* clang or GCC since 3.0 */
    241 #define _MHD_GCC_PRAG(x) _Pragma(#x)
    242 #if (defined(__clang__) && \
    243   (__clang_major__ + 0 >= 5 || \
    244    (! defined(__apple_build_version__) && \
    245   (__clang_major__ + 0  > 3 || \
    246    (__clang_major__ + 0 == 3 && __clang_minor__ >=  3))))) || \
    247   __GNUC__ + 0 > 4 || (__GNUC__ + 0 == 4 && __GNUC_MINOR__ + 0 >= 8)
    248 /* clang >= 3.3 (or XCode's clang >= 5.0) or
    249    GCC >= 4.8 */
    250 #define _MHD_DEPR_MACRO(msg) _MHD_GCC_PRAG (GCC warning msg)
    251 #define _MHD_DEPR_IN_MACRO(msg) _MHD_DEPR_MACRO (msg)
    252 #else /* older clang or GCC */
    253 /* clang < 3.3, XCode's clang < 5.0, 3.0 <= GCC < 4.8 */
    254 #define _MHD_DEPR_MACRO(msg) _MHD_GCC_PRAG (message msg)
    255 #if (defined(__clang__) && \
    256   (__clang_major__ + 0  > 2 || \
    257    (__clang_major__ + 0 == 2 && __clang_minor__ >= 9)))  /* clang >= 2.9 */
    258 /* clang handles inline pragmas better than GCC */
    259 #define _MHD_DEPR_IN_MACRO(msg) _MHD_DEPR_MACRO (msg)
    260 #endif /* clang >= 2.9 */
    261 #endif  /* older clang or GCC */
    262 /* #elif defined(SOMEMACRO) */ /* add compiler-specific macros here if required */
    263 #endif /* clang || GCC >= 3.0 */
    264 #endif /* !_MHD_DEPR_MACRO */
    265 
    266 #ifndef _MHD_DEPR_MACRO
    267 #define _MHD_DEPR_MACRO(msg)
    268 #endif /* !_MHD_DEPR_MACRO */
    269 
    270 #ifndef _MHD_DEPR_IN_MACRO
    271 #define _MHD_NO_DEPR_IN_MACRO 1
    272 #define _MHD_DEPR_IN_MACRO(msg)
    273 #endif /* !_MHD_DEPR_IN_MACRO */
    274 
    275 #ifndef _MHD_DEPR_FUNC
    276 #if defined(_MSC_FULL_VER) && _MSC_VER + 0 >= 1400
    277 /* VS 2005 or later */
    278 #define _MHD_DEPR_FUNC(msg) __declspec(deprecated (msg))
    279 #elif defined(_MSC_FULL_VER) && _MSC_VER + 0 >= 1310
    280 /* VS .NET 2003 deprecation does not support custom messages */
    281 #define _MHD_DEPR_FUNC(msg) __declspec(deprecated)
    282 #elif (__GNUC__ + 0 >= 5) || (defined(__clang__) && \
    283   (__clang_major__ + 0 > 2 || \
    284    (__clang_major__ + 0 == 2 && __clang_minor__ >=  9)))
    285 /* GCC >= 5.0 or clang >= 2.9 */
    286 #define _MHD_DEPR_FUNC(msg) __attribute__((deprecated (msg)))
    287 #elif defined(__clang__) || __GNUC__ + 0 > 3 || \
    288   (__GNUC__ + 0 == 3 && __GNUC_MINOR__ + 0 >= 1)
    289 /* 3.1 <= GCC < 5.0 or clang < 2.9 */
    290 /* old GCC-style deprecation does not support custom messages */
    291 #define _MHD_DEPR_FUNC(msg) __attribute__((__deprecated__))
    292 /* #elif defined(SOMEMACRO) */ /* add compiler-specific macros here if required */
    293 #endif /* clang < 2.9 || GCC >= 3.1 */
    294 #endif /* !_MHD_DEPR_FUNC */
    295 
    296 #ifndef _MHD_DEPR_FUNC
    297 #define _MHD_NO_DEPR_FUNC 1
    298 #define _MHD_DEPR_FUNC(msg)
    299 #endif /* !_MHD_DEPR_FUNC */
    300 
    301 /**
    302  * Not all architectures and `printf()`'s support the `long long` type.
    303  * This gives the ability to replace `long long` with just a `long`,
    304  * standard `int` or a `short`.
    305  */
    306 #ifndef MHD_LONG_LONG
    307 /**
    308  * @deprecated use #MHD_UNSIGNED_LONG_LONG instead!
    309  */
    310 #define MHD_LONG_LONG long long
    311 #define MHD_UNSIGNED_LONG_LONG unsigned long long
    312 #else /* MHD_LONG_LONG */
    313 _MHD_DEPR_MACRO ( \
    314   "Macro MHD_LONG_LONG is deprecated, use MHD_UNSIGNED_LONG_LONG")
    315 #endif
    316 /**
    317  * Format string for printing a variable of type #MHD_LONG_LONG.
    318  * You should only redefine this if you also define #MHD_LONG_LONG.
    319  */
    320 #ifndef MHD_LONG_LONG_PRINTF
    321 /**
    322  * @deprecated use #MHD_UNSIGNED_LONG_LONG_PRINTF instead!
    323  */
    324 #define MHD_LONG_LONG_PRINTF "ll"
    325 #define MHD_UNSIGNED_LONG_LONG_PRINTF "%llu"
    326 #else /* MHD_LONG_LONG_PRINTF */
    327 _MHD_DEPR_MACRO ( \
    328   "Macro MHD_LONG_LONG_PRINTF is deprecated, use MHD_UNSIGNED_LONG_LONG_PRINTF")
    329 #endif
    330 
    331 
    332 /**
    333  * @defgroup httpcode HTTP response codes.
    334  * These are the status codes defined for HTTP responses.
    335  * See: https://www.iana.org/assignments/http-status-codes/http-status-codes.xhtml
    336  * Registry export date: 2023-09-29
    337  * @{
    338  */
    339 
    340 /* 100 "Continue".            RFC9110, Section 15.2.1. */
    341 #define MHD_HTTP_CONTINUE                    100
    342 /* 101 "Switching Protocols". RFC9110, Section 15.2.2. */
    343 #define MHD_HTTP_SWITCHING_PROTOCOLS         101
    344 /* 102 "Processing".          RFC2518. */
    345 #define MHD_HTTP_PROCESSING                  102
    346 /* 103 "Early Hints".         RFC8297. */
    347 #define MHD_HTTP_EARLY_HINTS                 103
    348 
    349 /* 200 "OK".                  RFC9110, Section 15.3.1. */
    350 #define MHD_HTTP_OK                          200
    351 /* 201 "Created".             RFC9110, Section 15.3.2. */
    352 #define MHD_HTTP_CREATED                     201
    353 /* 202 "Accepted".            RFC9110, Section 15.3.3. */
    354 #define MHD_HTTP_ACCEPTED                    202
    355 /* 203 "Non-Authoritative Information". RFC9110, Section 15.3.4. */
    356 #define MHD_HTTP_NON_AUTHORITATIVE_INFORMATION 203
    357 /* 204 "No Content".          RFC9110, Section 15.3.5. */
    358 #define MHD_HTTP_NO_CONTENT                  204
    359 /* 205 "Reset Content".       RFC9110, Section 15.3.6. */
    360 #define MHD_HTTP_RESET_CONTENT               205
    361 /* 206 "Partial Content".     RFC9110, Section 15.3.7. */
    362 #define MHD_HTTP_PARTIAL_CONTENT             206
    363 /* 207 "Multi-Status".        RFC4918. */
    364 #define MHD_HTTP_MULTI_STATUS                207
    365 /* 208 "Already Reported".    RFC5842. */
    366 #define MHD_HTTP_ALREADY_REPORTED            208
    367 
    368 /* 226 "IM Used".             RFC3229. */
    369 #define MHD_HTTP_IM_USED                     226
    370 
    371 /* 300 "Multiple Choices".    RFC9110, Section 15.4.1. */
    372 #define MHD_HTTP_MULTIPLE_CHOICES            300
    373 /* 301 "Moved Permanently".   RFC9110, Section 15.4.2. */
    374 #define MHD_HTTP_MOVED_PERMANENTLY           301
    375 /* 302 "Found".               RFC9110, Section 15.4.3. */
    376 #define MHD_HTTP_FOUND                       302
    377 /* 303 "See Other".           RFC9110, Section 15.4.4. */
    378 #define MHD_HTTP_SEE_OTHER                   303
    379 /* 304 "Not Modified".        RFC9110, Section 15.4.5. */
    380 #define MHD_HTTP_NOT_MODIFIED                304
    381 /* 305 "Use Proxy".           RFC9110, Section 15.4.6. */
    382 #define MHD_HTTP_USE_PROXY                   305
    383 /* 306 "Switch Proxy".        Not used! RFC9110, Section 15.4.7. */
    384 #define MHD_HTTP_SWITCH_PROXY                306
    385 /* 307 "Temporary Redirect".  RFC9110, Section 15.4.8. */
    386 #define MHD_HTTP_TEMPORARY_REDIRECT          307
    387 /* 308 "Permanent Redirect".  RFC9110, Section 15.4.9. */
    388 #define MHD_HTTP_PERMANENT_REDIRECT          308
    389 
    390 /* 400 "Bad Request".         RFC9110, Section 15.5.1. */
    391 #define MHD_HTTP_BAD_REQUEST                 400
    392 /* 401 "Unauthorized".        RFC9110, Section 15.5.2. */
    393 #define MHD_HTTP_UNAUTHORIZED                401
    394 /* 402 "Payment Required".    RFC9110, Section 15.5.3. */
    395 #define MHD_HTTP_PAYMENT_REQUIRED            402
    396 /* 403 "Forbidden".           RFC9110, Section 15.5.4. */
    397 #define MHD_HTTP_FORBIDDEN                   403
    398 /* 404 "Not Found".           RFC9110, Section 15.5.5. */
    399 #define MHD_HTTP_NOT_FOUND                   404
    400 /* 405 "Method Not Allowed".  RFC9110, Section 15.5.6. */
    401 #define MHD_HTTP_METHOD_NOT_ALLOWED          405
    402 /* 406 "Not Acceptable".      RFC9110, Section 15.5.7. */
    403 #define MHD_HTTP_NOT_ACCEPTABLE              406
    404 /* 407 "Proxy Authentication Required". RFC9110, Section 15.5.8. */
    405 #define MHD_HTTP_PROXY_AUTHENTICATION_REQUIRED 407
    406 /* 408 "Request Timeout".     RFC9110, Section 15.5.9. */
    407 #define MHD_HTTP_REQUEST_TIMEOUT             408
    408 /* 409 "Conflict".            RFC9110, Section 15.5.10. */
    409 #define MHD_HTTP_CONFLICT                    409
    410 /* 410 "Gone".                RFC9110, Section 15.5.11. */
    411 #define MHD_HTTP_GONE                        410
    412 /* 411 "Length Required".     RFC9110, Section 15.5.12. */
    413 #define MHD_HTTP_LENGTH_REQUIRED             411
    414 /* 412 "Precondition Failed". RFC9110, Section 15.5.13. */
    415 #define MHD_HTTP_PRECONDITION_FAILED         412
    416 /* 413 "Content Too Large".   RFC9110, Section 15.5.14. */
    417 #define MHD_HTTP_CONTENT_TOO_LARGE           413
    418 /* 414 "URI Too Long".        RFC9110, Section 15.5.15. */
    419 #define MHD_HTTP_URI_TOO_LONG                414
    420 /* 415 "Unsupported Media Type". RFC9110, Section 15.5.16. */
    421 #define MHD_HTTP_UNSUPPORTED_MEDIA_TYPE      415
    422 /* 416 "Range Not Satisfiable". RFC9110, Section 15.5.17. */
    423 #define MHD_HTTP_RANGE_NOT_SATISFIABLE       416
    424 /* 417 "Expectation Failed".  RFC9110, Section 15.5.18. */
    425 #define MHD_HTTP_EXPECTATION_FAILED          417
    426 
    427 
    428 /* 421 "Misdirected Request". RFC9110, Section 15.5.20. */
    429 #define MHD_HTTP_MISDIRECTED_REQUEST         421
    430 /* 422 "Unprocessable Content". RFC9110, Section 15.5.21. */
    431 #define MHD_HTTP_UNPROCESSABLE_CONTENT       422
    432 /* 423 "Locked".              RFC4918. */
    433 #define MHD_HTTP_LOCKED                      423
    434 /* 424 "Failed Dependency".   RFC4918. */
    435 #define MHD_HTTP_FAILED_DEPENDENCY           424
    436 /* 425 "Too Early".           RFC8470. */
    437 #define MHD_HTTP_TOO_EARLY                   425
    438 /* 426 "Upgrade Required".    RFC9110, Section 15.5.22. */
    439 #define MHD_HTTP_UPGRADE_REQUIRED            426
    440 
    441 /* 428 "Precondition Required". RFC6585. */
    442 #define MHD_HTTP_PRECONDITION_REQUIRED       428
    443 /* 429 "Too Many Requests".   RFC6585. */
    444 #define MHD_HTTP_TOO_MANY_REQUESTS           429
    445 
    446 /* 431 "Request Header Fields Too Large". RFC6585. */
    447 #define MHD_HTTP_REQUEST_HEADER_FIELDS_TOO_LARGE 431
    448 
    449 /* 451 "Unavailable For Legal Reasons". RFC7725. */
    450 #define MHD_HTTP_UNAVAILABLE_FOR_LEGAL_REASONS 451
    451 
    452 /* 500 "Internal Server Error". RFC9110, Section 15.6.1. */
    453 #define MHD_HTTP_INTERNAL_SERVER_ERROR       500
    454 /* 501 "Not Implemented".     RFC9110, Section 15.6.2. */
    455 #define MHD_HTTP_NOT_IMPLEMENTED             501
    456 /* 502 "Bad Gateway".         RFC9110, Section 15.6.3. */
    457 #define MHD_HTTP_BAD_GATEWAY                 502
    458 /* 503 "Service Unavailable". RFC9110, Section 15.6.4. */
    459 #define MHD_HTTP_SERVICE_UNAVAILABLE         503
    460 /* 504 "Gateway Timeout".     RFC9110, Section 15.6.5. */
    461 #define MHD_HTTP_GATEWAY_TIMEOUT             504
    462 /* 505 "HTTP Version Not Supported". RFC9110, Section 15.6.6. */
    463 #define MHD_HTTP_HTTP_VERSION_NOT_SUPPORTED  505
    464 /* 506 "Variant Also Negotiates". RFC2295. */
    465 #define MHD_HTTP_VARIANT_ALSO_NEGOTIATES     506
    466 /* 507 "Insufficient Storage". RFC4918. */
    467 #define MHD_HTTP_INSUFFICIENT_STORAGE        507
    468 /* 508 "Loop Detected".       RFC5842. */
    469 #define MHD_HTTP_LOOP_DETECTED               508
    470 
    471 /* 510 "Not Extended".        (OBSOLETED) RFC2774; status-change-http-experiments-to-historic. */
    472 #define MHD_HTTP_NOT_EXTENDED                510
    473 /* 511 "Network Authentication Required". RFC6585. */
    474 #define MHD_HTTP_NETWORK_AUTHENTICATION_REQUIRED 511
    475 
    476 
    477 /* Not registered non-standard codes */
    478 /* 449 "Reply With".          MS IIS extension. */
    479 #define MHD_HTTP_RETRY_WITH                  449
    480 
    481 /* 450 "Blocked by Windows Parental Controls". MS extension. */
    482 #define MHD_HTTP_BLOCKED_BY_WINDOWS_PARENTAL_CONTROLS 450
    483 
    484 /* 509 "Bandwidth Limit Exceeded". Apache extension. */
    485 #define MHD_HTTP_BANDWIDTH_LIMIT_EXCEEDED    509
    486 
    487 /* Deprecated names and codes */
    488 /** @deprecated */
    489 #define MHD_HTTP_METHOD_NOT_ACCEPTABLE _MHD_DEPR_IN_MACRO ( \
    490           "Value MHD_HTTP_METHOD_NOT_ACCEPTABLE is deprecated, use MHD_HTTP_NOT_ACCEPTABLE" \
    491           ) 406
    492 
    493 /** @deprecated */
    494 #define MHD_HTTP_REQUEST_ENTITY_TOO_LARGE _MHD_DEPR_IN_MACRO ( \
    495           "Value MHD_HTTP_REQUEST_ENTITY_TOO_LARGE is deprecated, use MHD_HTTP_CONTENT_TOO_LARGE" \
    496           ) 413
    497 
    498 /** @deprecated */
    499 #define MHD_HTTP_PAYLOAD_TOO_LARGE _MHD_DEPR_IN_MACRO ( \
    500           "Value MHD_HTTP_PAYLOAD_TOO_LARGE is deprecated use MHD_HTTP_CONTENT_TOO_LARGE" \
    501           ) 413
    502 
    503 /** @deprecated */
    504 #define MHD_HTTP_REQUEST_URI_TOO_LONG _MHD_DEPR_IN_MACRO ( \
    505           "Value MHD_HTTP_REQUEST_URI_TOO_LONG is deprecated, use MHD_HTTP_URI_TOO_LONG" \
    506           ) 414
    507 
    508 /** @deprecated */
    509 #define MHD_HTTP_REQUESTED_RANGE_NOT_SATISFIABLE _MHD_DEPR_IN_MACRO ( \
    510           "Value MHD_HTTP_REQUESTED_RANGE_NOT_SATISFIABLE is deprecated, use MHD_HTTP_RANGE_NOT_SATISFIABLE" \
    511           ) 416
    512 
    513 /** @deprecated */
    514 #define MHD_HTTP_UNPROCESSABLE_ENTITY _MHD_DEPR_IN_MACRO ( \
    515           "Value MHD_HTTP_UNPROCESSABLE_ENTITY is deprecated, use MHD_HTTP_UNPROCESSABLE_CONTENT" \
    516           ) 422
    517 
    518 /** @deprecated */
    519 #define MHD_HTTP_UNORDERED_COLLECTION _MHD_DEPR_IN_MACRO ( \
    520           "Value MHD_HTTP_UNORDERED_COLLECTION is deprecated as it was removed from RFC" \
    521           ) 425
    522 
    523 /** @deprecated */
    524 #define MHD_HTTP_NO_RESPONSE _MHD_DEPR_IN_MACRO ( \
    525           "Value MHD_HTTP_NO_RESPONSE is deprecated as it is nginx internal code for logs only" \
    526           ) 444
    527 
    528 
    529 /** @} */ /* end of group httpcode */
    530 
    531 /**
    532  * Returns the string reason phrase for a response code.
    533  *
    534  * If message string is not available for a status code,
    535  * "Unknown" string will be returned.
    536  */
    537 _MHD_EXTERN const char *
    538 MHD_get_reason_phrase_for (unsigned int code);
    539 
    540 
    541 /**
    542  * Returns the length of the string reason phrase for a response code.
    543  *
    544  * If message string is not available for a status code,
    545  * 0 is returned.
    546  */
    547 _MHD_EXTERN size_t
    548 MHD_get_reason_phrase_len_for (unsigned int code);
    549 
    550 /**
    551  * Flag to be or-ed with MHD_HTTP status code for
    552  * SHOUTcast.  This will cause the response to begin
    553  * with the SHOUTcast "ICY" line instead of "HTTP/1.x".
    554  * @ingroup specialized
    555  */
    556 #define MHD_ICY_FLAG ((uint32_t) (((uint32_t) 1) << 31))
    557 
    558 /**
    559  * @defgroup headers HTTP headers
    560  * The standard headers found in HTTP requests and responses.
    561  * See: https://www.iana.org/assignments/http-fields/http-fields.xhtml
    562  * Registry export date: 2023-10-02
    563  * @{
    564  */
    565 
    566 /* Main HTTP headers. */
    567 /* Permanent.     RFC9110, Section 12.5.1: HTTP Semantics */
    568 #define MHD_HTTP_HEADER_ACCEPT       "Accept"
    569 /* Deprecated.    RFC9110, Section 12.5.2: HTTP Semantics */
    570 #define MHD_HTTP_HEADER_ACCEPT_CHARSET "Accept-Charset"
    571 /* Permanent.     RFC9110, Section 12.5.3: HTTP Semantics */
    572 #define MHD_HTTP_HEADER_ACCEPT_ENCODING "Accept-Encoding"
    573 /* Permanent.     RFC9110, Section 12.5.4: HTTP Semantics */
    574 #define MHD_HTTP_HEADER_ACCEPT_LANGUAGE "Accept-Language"
    575 /* Permanent.     RFC9110, Section 14.3: HTTP Semantics */
    576 #define MHD_HTTP_HEADER_ACCEPT_RANGES "Accept-Ranges"
    577 /* Permanent.     RFC9111, Section 5.1: HTTP Caching */
    578 #define MHD_HTTP_HEADER_AGE          "Age"
    579 /* Permanent.     RFC9110, Section 10.2.1: HTTP Semantics */
    580 #define MHD_HTTP_HEADER_ALLOW        "Allow"
    581 /* Permanent.     RFC9110, Section 11.6.3: HTTP Semantics */
    582 #define MHD_HTTP_HEADER_AUTHENTICATION_INFO "Authentication-Info"
    583 /* Permanent.     RFC9110, Section 11.6.2: HTTP Semantics */
    584 #define MHD_HTTP_HEADER_AUTHORIZATION "Authorization"
    585 /* Permanent.     RFC9111, Section 5.2 */
    586 #define MHD_HTTP_HEADER_CACHE_CONTROL "Cache-Control"
    587 /* Permanent.     RFC9112, Section 9.6: HTTP/1.1 */
    588 #define MHD_HTTP_HEADER_CLOSE        "Close"
    589 /* Permanent.     RFC9110, Section 7.6.1: HTTP Semantics */
    590 #define MHD_HTTP_HEADER_CONNECTION   "Connection"
    591 /* Permanent.     RFC9110, Section 8.4: HTTP Semantics */
    592 #define MHD_HTTP_HEADER_CONTENT_ENCODING "Content-Encoding"
    593 /* Permanent.     RFC9110, Section 8.5: HTTP Semantics */
    594 #define MHD_HTTP_HEADER_CONTENT_LANGUAGE "Content-Language"
    595 /* Permanent.     RFC9110, Section 8.6: HTTP Semantics */
    596 #define MHD_HTTP_HEADER_CONTENT_LENGTH "Content-Length"
    597 /* Permanent.     RFC9110, Section 8.7: HTTP Semantics */
    598 #define MHD_HTTP_HEADER_CONTENT_LOCATION "Content-Location"
    599 /* Permanent.     RFC9110, Section 14.4: HTTP Semantics */
    600 #define MHD_HTTP_HEADER_CONTENT_RANGE "Content-Range"
    601 /* Permanent.     RFC9110, Section 8.3: HTTP Semantics */
    602 #define MHD_HTTP_HEADER_CONTENT_TYPE "Content-Type"
    603 /* Permanent.     RFC9110, Section 6.6.1: HTTP Semantics */
    604 #define MHD_HTTP_HEADER_DATE         "Date"
    605 /* Permanent.     RFC9110, Section 8.8.3: HTTP Semantics */
    606 #define MHD_HTTP_HEADER_ETAG         "ETag"
    607 /* Permanent.     RFC9110, Section 10.1.1: HTTP Semantics */
    608 #define MHD_HTTP_HEADER_EXPECT       "Expect"
    609 /* Permanent.     RFC9111, Section 5.3: HTTP Caching */
    610 #define MHD_HTTP_HEADER_EXPIRES      "Expires"
    611 /* Permanent.     RFC9110, Section 10.1.2: HTTP Semantics */
    612 #define MHD_HTTP_HEADER_FROM         "From"
    613 /* Permanent.     RFC9110, Section 7.2: HTTP Semantics */
    614 #define MHD_HTTP_HEADER_HOST         "Host"
    615 /* Permanent.     RFC9110, Section 13.1.1: HTTP Semantics */
    616 #define MHD_HTTP_HEADER_IF_MATCH     "If-Match"
    617 /* Permanent.     RFC9110, Section 13.1.3: HTTP Semantics */
    618 #define MHD_HTTP_HEADER_IF_MODIFIED_SINCE "If-Modified-Since"
    619 /* Permanent.     RFC9110, Section 13.1.2: HTTP Semantics */
    620 #define MHD_HTTP_HEADER_IF_NONE_MATCH "If-None-Match"
    621 /* Permanent.     RFC9110, Section 13.1.5: HTTP Semantics */
    622 #define MHD_HTTP_HEADER_IF_RANGE     "If-Range"
    623 /* Permanent.     RFC9110, Section 13.1.4: HTTP Semantics */
    624 #define MHD_HTTP_HEADER_IF_UNMODIFIED_SINCE "If-Unmodified-Since"
    625 /* Permanent.     RFC9110, Section 8.8.2: HTTP Semantics */
    626 #define MHD_HTTP_HEADER_LAST_MODIFIED "Last-Modified"
    627 /* Permanent.     RFC9110, Section 10.2.2: HTTP Semantics */
    628 #define MHD_HTTP_HEADER_LOCATION     "Location"
    629 /* Permanent.     RFC9110, Section 7.6.2: HTTP Semantics */
    630 #define MHD_HTTP_HEADER_MAX_FORWARDS "Max-Forwards"
    631 /* Permanent.     RFC9112, Appendix B.1: HTTP/1.1 */
    632 #define MHD_HTTP_HEADER_MIME_VERSION "MIME-Version"
    633 /* Deprecated.    RFC9111, Section 5.4: HTTP Caching */
    634 #define MHD_HTTP_HEADER_PRAGMA       "Pragma"
    635 /* Permanent.     RFC9110, Section 11.7.1: HTTP Semantics */
    636 #define MHD_HTTP_HEADER_PROXY_AUTHENTICATE "Proxy-Authenticate"
    637 /* Permanent.     RFC9110, Section 11.7.3: HTTP Semantics */
    638 #define MHD_HTTP_HEADER_PROXY_AUTHENTICATION_INFO "Proxy-Authentication-Info"
    639 /* Permanent.     RFC9110, Section 11.7.2: HTTP Semantics */
    640 #define MHD_HTTP_HEADER_PROXY_AUTHORIZATION "Proxy-Authorization"
    641 /* Permanent.     RFC9110, Section 14.2: HTTP Semantics */
    642 #define MHD_HTTP_HEADER_RANGE        "Range"
    643 /* Permanent.     RFC9110, Section 10.1.3: HTTP Semantics */
    644 #define MHD_HTTP_HEADER_REFERER      "Referer"
    645 /* Permanent.     RFC9110, Section 10.2.3: HTTP Semantics */
    646 #define MHD_HTTP_HEADER_RETRY_AFTER  "Retry-After"
    647 /* Permanent.     RFC9110, Section 10.2.4: HTTP Semantics */
    648 #define MHD_HTTP_HEADER_SERVER       "Server"
    649 /* Permanent.     RFC9110, Section 10.1.4: HTTP Semantics */
    650 #define MHD_HTTP_HEADER_TE           "TE"
    651 /* Permanent.     RFC9110, Section 6.6.2: HTTP Semantics */
    652 #define MHD_HTTP_HEADER_TRAILER      "Trailer"
    653 /* Permanent.     RFC9112, Section 6.1: HTTP Semantics */
    654 #define MHD_HTTP_HEADER_TRANSFER_ENCODING "Transfer-Encoding"
    655 /* Permanent.     RFC9110, Section 7.8: HTTP Semantics */
    656 #define MHD_HTTP_HEADER_UPGRADE      "Upgrade"
    657 /* Permanent.     RFC9110, Section 10.1.5: HTTP Semantics */
    658 #define MHD_HTTP_HEADER_USER_AGENT   "User-Agent"
    659 /* Permanent.     RFC9110, Section 12.5.5: HTTP Semantics */
    660 #define MHD_HTTP_HEADER_VARY         "Vary"
    661 /* Permanent.     RFC9110, Section 7.6.3: HTTP Semantics */
    662 #define MHD_HTTP_HEADER_VIA          "Via"
    663 /* Permanent.     RFC9110, Section 11.6.1: HTTP Semantics */
    664 #define MHD_HTTP_HEADER_WWW_AUTHENTICATE "WWW-Authenticate"
    665 /* Permanent.     RFC9110, Section 12.5.5: HTTP Semantics */
    666 #define MHD_HTTP_HEADER_ASTERISK     "*"
    667 
    668 /* Additional HTTP headers. */
    669 /* Permanent.     RFC 3229: Delta encoding in HTTP */
    670 #define MHD_HTTP_HEADER_A_IM         "A-IM"
    671 /* Permanent.     RFC 2324: Hyper Text Coffee Pot Control Protocol (HTCPCP/1.0) */
    672 #define MHD_HTTP_HEADER_ACCEPT_ADDITIONS "Accept-Additions"
    673 /* Permanent.     RFC 8942, Section 3.1: HTTP Client Hints */
    674 #define MHD_HTTP_HEADER_ACCEPT_CH    "Accept-CH"
    675 /* Permanent.     RFC 7089: HTTP Framework for Time-Based Access to Resource States -- Memento */
    676 #define MHD_HTTP_HEADER_ACCEPT_DATETIME "Accept-Datetime"
    677 /* Permanent.     RFC 2295: Transparent Content Negotiation in HTTP */
    678 #define MHD_HTTP_HEADER_ACCEPT_FEATURES "Accept-Features"
    679 /* Permanent.     RFC 5789: PATCH Method for HTTP */
    680 #define MHD_HTTP_HEADER_ACCEPT_PATCH "Accept-Patch"
    681 /* Permanent.     Linked Data Platform 1.0 */
    682 #define MHD_HTTP_HEADER_ACCEPT_POST  "Accept-Post"
    683 /* Permanent.     RFC-ietf-httpbis-message-signatures-19, Section 5.1: HTTP Message Signatures */
    684 #define MHD_HTTP_HEADER_ACCEPT_SIGNATURE "Accept-Signature"
    685 /* Permanent.     Fetch */
    686 #define MHD_HTTP_HEADER_ACCESS_CONTROL_ALLOW_CREDENTIALS \
    687         "Access-Control-Allow-Credentials"
    688 /* Permanent.     Fetch */
    689 #define MHD_HTTP_HEADER_ACCESS_CONTROL_ALLOW_HEADERS \
    690         "Access-Control-Allow-Headers"
    691 /* Permanent.     Fetch */
    692 #define MHD_HTTP_HEADER_ACCESS_CONTROL_ALLOW_METHODS \
    693         "Access-Control-Allow-Methods"
    694 /* Permanent.     Fetch */
    695 #define MHD_HTTP_HEADER_ACCESS_CONTROL_ALLOW_ORIGIN \
    696         "Access-Control-Allow-Origin"
    697 /* Permanent.     Fetch */
    698 #define MHD_HTTP_HEADER_ACCESS_CONTROL_EXPOSE_HEADERS \
    699         "Access-Control-Expose-Headers"
    700 /* Permanent.     Fetch */
    701 #define MHD_HTTP_HEADER_ACCESS_CONTROL_MAX_AGE "Access-Control-Max-Age"
    702 /* Permanent.     Fetch */
    703 #define MHD_HTTP_HEADER_ACCESS_CONTROL_REQUEST_HEADERS \
    704         "Access-Control-Request-Headers"
    705 /* Permanent.     Fetch */
    706 #define MHD_HTTP_HEADER_ACCESS_CONTROL_REQUEST_METHOD \
    707         "Access-Control-Request-Method"
    708 /* Permanent.     RFC 7639, Section 2: The ALPN HTTP Header Field */
    709 #define MHD_HTTP_HEADER_ALPN         "ALPN"
    710 /* Permanent.     RFC 7838: HTTP Alternative Services */
    711 #define MHD_HTTP_HEADER_ALT_SVC      "Alt-Svc"
    712 /* Permanent.     RFC 7838: HTTP Alternative Services */
    713 #define MHD_HTTP_HEADER_ALT_USED     "Alt-Used"
    714 /* Permanent.     RFC 2295: Transparent Content Negotiation in HTTP */
    715 #define MHD_HTTP_HEADER_ALTERNATES   "Alternates"
    716 /* Permanent.     RFC 4437: Web Distributed Authoring and Versioning (WebDAV) Redirect Reference Resources */
    717 #define MHD_HTTP_HEADER_APPLY_TO_REDIRECT_REF "Apply-To-Redirect-Ref"
    718 /* Permanent.     RFC 8053, Section 4: HTTP Authentication Extensions for Interactive Clients */
    719 #define MHD_HTTP_HEADER_AUTHENTICATION_CONTROL "Authentication-Control"
    720 /* Permanent.     RFC9211: The Cache-Status HTTP Response Header Field */
    721 #define MHD_HTTP_HEADER_CACHE_STATUS "Cache-Status"
    722 /* Permanent.     RFC 8607, Section 5.1: Calendaring Extensions to WebDAV (CalDAV): Managed Attachments */
    723 #define MHD_HTTP_HEADER_CAL_MANAGED_ID "Cal-Managed-ID"
    724 /* Permanent.     RFC 7809, Section 7.1: Calendaring Extensions to WebDAV (CalDAV): Time Zones by Reference */
    725 #define MHD_HTTP_HEADER_CALDAV_TIMEZONES "CalDAV-Timezones"
    726 /* Permanent.     RFC9297 */
    727 #define MHD_HTTP_HEADER_CAPSULE_PROTOCOL "Capsule-Protocol"
    728 /* Permanent.     RFC9213: Targeted HTTP Cache Control */
    729 #define MHD_HTTP_HEADER_CDN_CACHE_CONTROL "CDN-Cache-Control"
    730 /* Permanent.     RFC 8586: Loop Detection in Content Delivery Networks (CDNs) */
    731 #define MHD_HTTP_HEADER_CDN_LOOP     "CDN-Loop"
    732 /* Permanent.     RFC 8739, Section 3.3: Support for Short-Term, Automatically Renewed (STAR) Certificates in the Automated Certificate Management Environment (ACME) */
    733 #define MHD_HTTP_HEADER_CERT_NOT_AFTER "Cert-Not-After"
    734 /* Permanent.     RFC 8739, Section 3.3: Support for Short-Term, Automatically Renewed (STAR) Certificates in the Automated Certificate Management Environment (ACME) */
    735 #define MHD_HTTP_HEADER_CERT_NOT_BEFORE "Cert-Not-Before"
    736 /* Permanent.     Clear Site Data */
    737 #define MHD_HTTP_HEADER_CLEAR_SITE_DATA "Clear-Site-Data"
    738 /* Permanent.     RFC9440, Section 2: Client-Cert HTTP Header Field */
    739 #define MHD_HTTP_HEADER_CLIENT_CERT  "Client-Cert"
    740 /* Permanent.     RFC9440, Section 2: Client-Cert HTTP Header Field */
    741 #define MHD_HTTP_HEADER_CLIENT_CERT_CHAIN "Client-Cert-Chain"
    742 /* Permanent.     RFC-ietf-httpbis-digest-headers-13, Section 2: Digest Fields */
    743 #define MHD_HTTP_HEADER_CONTENT_DIGEST "Content-Digest"
    744 /* Permanent.     RFC 6266: Use of the Content-Disposition Header Field in the Hypertext Transfer Protocol (HTTP) */
    745 #define MHD_HTTP_HEADER_CONTENT_DISPOSITION "Content-Disposition"
    746 /* Permanent.     The HTTP Distribution and Replication Protocol */
    747 #define MHD_HTTP_HEADER_CONTENT_ID   "Content-ID"
    748 /* Permanent.     Content Security Policy Level 3 */
    749 #define MHD_HTTP_HEADER_CONTENT_SECURITY_POLICY "Content-Security-Policy"
    750 /* Permanent.     Content Security Policy Level 3 */
    751 #define MHD_HTTP_HEADER_CONTENT_SECURITY_POLICY_REPORT_ONLY \
    752         "Content-Security-Policy-Report-Only"
    753 /* Permanent.     RFC 6265: HTTP State Management Mechanism */
    754 #define MHD_HTTP_HEADER_COOKIE       "Cookie"
    755 /* Permanent.     HTML */
    756 #define MHD_HTTP_HEADER_CROSS_ORIGIN_EMBEDDER_POLICY \
    757         "Cross-Origin-Embedder-Policy"
    758 /* Permanent.     HTML */
    759 #define MHD_HTTP_HEADER_CROSS_ORIGIN_EMBEDDER_POLICY_REPORT_ONLY \
    760         "Cross-Origin-Embedder-Policy-Report-Only"
    761 /* Permanent.     HTML */
    762 #define MHD_HTTP_HEADER_CROSS_ORIGIN_OPENER_POLICY "Cross-Origin-Opener-Policy"
    763 /* Permanent.     HTML */
    764 #define MHD_HTTP_HEADER_CROSS_ORIGIN_OPENER_POLICY_REPORT_ONLY \
    765         "Cross-Origin-Opener-Policy-Report-Only"
    766 /* Permanent.     Fetch */
    767 #define MHD_HTTP_HEADER_CROSS_ORIGIN_RESOURCE_POLICY \
    768         "Cross-Origin-Resource-Policy"
    769 /* Permanent.     RFC 5323: Web Distributed Authoring and Versioning (WebDAV) SEARCH */
    770 #define MHD_HTTP_HEADER_DASL         "DASL"
    771 /* Permanent.     RFC 4918: HTTP Extensions for Web Distributed Authoring and Versioning (WebDAV) */
    772 #define MHD_HTTP_HEADER_DAV          "DAV"
    773 /* Permanent.     RFC 3229: Delta encoding in HTTP */
    774 #define MHD_HTTP_HEADER_DELTA_BASE   "Delta-Base"
    775 /* Permanent.     RFC 4918: HTTP Extensions for Web Distributed Authoring and Versioning (WebDAV) */
    776 #define MHD_HTTP_HEADER_DEPTH        "Depth"
    777 /* Permanent.     RFC 4918: HTTP Extensions for Web Distributed Authoring and Versioning (WebDAV) */
    778 #define MHD_HTTP_HEADER_DESTINATION  "Destination"
    779 /* Permanent.     The HTTP Distribution and Replication Protocol */
    780 #define MHD_HTTP_HEADER_DIFFERENTIAL_ID "Differential-ID"
    781 /* Permanent.     RFC9449: OAuth 2.0 Demonstrating Proof of Possession (DPoP) */
    782 #define MHD_HTTP_HEADER_DPOP         "DPoP"
    783 /* Permanent.     RFC9449: OAuth 2.0 Demonstrating Proof of Possession (DPoP) */
    784 #define MHD_HTTP_HEADER_DPOP_NONCE   "DPoP-Nonce"
    785 /* Permanent.     RFC 8470: Using Early Data in HTTP */
    786 #define MHD_HTTP_HEADER_EARLY_DATA   "Early-Data"
    787 /* Permanent.     RFC9163: Expect-CT Extension for HTTP */
    788 #define MHD_HTTP_HEADER_EXPECT_CT    "Expect-CT"
    789 /* Permanent.     RFC 7239: Forwarded HTTP Extension */
    790 #define MHD_HTTP_HEADER_FORWARDED    "Forwarded"
    791 /* Permanent.     RFC 7486, Section 6.1.1: HTTP Origin-Bound Authentication (HOBA) */
    792 #define MHD_HTTP_HEADER_HOBAREG      "Hobareg"
    793 /* Permanent.     RFC 4918: HTTP Extensions for Web Distributed Authoring and Versioning (WebDAV) */
    794 #define MHD_HTTP_HEADER_IF           "If"
    795 /* Permanent.      RFC 6338: Scheduling Extensions to CalDAV */
    796 #define MHD_HTTP_HEADER_IF_SCHEDULE_TAG_MATCH "If-Schedule-Tag-Match"
    797 /* Permanent.     RFC 3229: Delta encoding in HTTP */
    798 #define MHD_HTTP_HEADER_IM           "IM"
    799 /* Permanent.     RFC 8473: Token Binding over HTTP */
    800 #define MHD_HTTP_HEADER_INCLUDE_REFERRED_TOKEN_BINDING_ID \
    801         "Include-Referred-Token-Binding-ID"
    802 /* Permanent.     RFC 2068: Hypertext Transfer Protocol -- HTTP/1.1 */
    803 #define MHD_HTTP_HEADER_KEEP_ALIVE   "Keep-Alive"
    804 /* Permanent.     RFC 3253: Versioning Extensions to WebDAV: (Web Distributed Authoring and Versioning) */
    805 #define MHD_HTTP_HEADER_LABEL        "Label"
    806 /* Permanent.     HTML */
    807 #define MHD_HTTP_HEADER_LAST_EVENT_ID "Last-Event-ID"
    808 /* Permanent.     RFC 8288: Web Linking */
    809 #define MHD_HTTP_HEADER_LINK         "Link"
    810 /* Permanent.     RFC 4918: HTTP Extensions for Web Distributed Authoring and Versioning (WebDAV) */
    811 #define MHD_HTTP_HEADER_LOCK_TOKEN   "Lock-Token"
    812 /* Permanent.     RFC 7089: HTTP Framework for Time-Based Access to Resource States -- Memento */
    813 #define MHD_HTTP_HEADER_MEMENTO_DATETIME "Memento-Datetime"
    814 /* Permanent.     RFC 2227: Simple Hit-Metering and Usage-Limiting for HTTP */
    815 #define MHD_HTTP_HEADER_METER        "Meter"
    816 /* Permanent.     RFC 2295: Transparent Content Negotiation in HTTP */
    817 #define MHD_HTTP_HEADER_NEGOTIATE    "Negotiate"
    818 /* Permanent.     Network Error Logging */
    819 #define MHD_HTTP_HEADER_NEL          "NEL"
    820 /* Permanent.     OData Version 4.01 Part 1: Protocol; OASIS; Chet_Ensign */
    821 #define MHD_HTTP_HEADER_ODATA_ENTITYID "OData-EntityId"
    822 /* Permanent.     OData Version 4.01 Part 1: Protocol; OASIS; Chet_Ensign */
    823 #define MHD_HTTP_HEADER_ODATA_ISOLATION "OData-Isolation"
    824 /* Permanent.     OData Version 4.01 Part 1: Protocol; OASIS; Chet_Ensign */
    825 #define MHD_HTTP_HEADER_ODATA_MAXVERSION "OData-MaxVersion"
    826 /* Permanent.     OData Version 4.01 Part 1: Protocol; OASIS; Chet_Ensign */
    827 #define MHD_HTTP_HEADER_ODATA_VERSION "OData-Version"
    828 /* Permanent.     RFC 8053, Section 3: HTTP Authentication Extensions for Interactive Clients */
    829 #define MHD_HTTP_HEADER_OPTIONAL_WWW_AUTHENTICATE "Optional-WWW-Authenticate"
    830 /* Permanent.     RFC 3648: Web Distributed Authoring and Versioning (WebDAV) Ordered Collections Protocol */
    831 #define MHD_HTTP_HEADER_ORDERING_TYPE "Ordering-Type"
    832 /* Permanent.     RFC 6454: The Web Origin Concept */
    833 #define MHD_HTTP_HEADER_ORIGIN       "Origin"
    834 /* Permanent.     HTML */
    835 #define MHD_HTTP_HEADER_ORIGIN_AGENT_CLUSTER "Origin-Agent-Cluster"
    836 /* Permanent.     RFC 8613, Section 11.1: Object Security for Constrained RESTful Environments (OSCORE) */
    837 #define MHD_HTTP_HEADER_OSCORE       "OSCORE"
    838 /* Permanent.     OASIS Project Specification 01; OASIS; Chet_Ensign */
    839 #define MHD_HTTP_HEADER_OSLC_CORE_VERSION "OSLC-Core-Version"
    840 /* Permanent.     RFC 4918: HTTP Extensions for Web Distributed Authoring and Versioning (WebDAV) */
    841 #define MHD_HTTP_HEADER_OVERWRITE    "Overwrite"
    842 /* Permanent.     HTML */
    843 #define MHD_HTTP_HEADER_PING_FROM    "Ping-From"
    844 /* Permanent.     HTML */
    845 #define MHD_HTTP_HEADER_PING_TO      "Ping-To"
    846 /* Permanent.     RFC 3648: Web Distributed Authoring and Versioning (WebDAV) Ordered Collections Protocol */
    847 #define MHD_HTTP_HEADER_POSITION     "Position"
    848 /* Permanent.     RFC 7240: Prefer Header for HTTP */
    849 #define MHD_HTTP_HEADER_PREFER       "Prefer"
    850 /* Permanent.     RFC 7240: Prefer Header for HTTP */
    851 #define MHD_HTTP_HEADER_PREFERENCE_APPLIED "Preference-Applied"
    852 /* Permanent.     RFC9218: Extensible Prioritization Scheme for HTTP */
    853 #define MHD_HTTP_HEADER_PRIORITY     "Priority"
    854 /* Permanent.     RFC9209: The Proxy-Status HTTP Response Header Field */
    855 #define MHD_HTTP_HEADER_PROXY_STATUS "Proxy-Status"
    856 /* Permanent.     RFC 7469: Public Key Pinning Extension for HTTP */
    857 #define MHD_HTTP_HEADER_PUBLIC_KEY_PINS "Public-Key-Pins"
    858 /* Permanent.     RFC 7469: Public Key Pinning Extension for HTTP */
    859 #define MHD_HTTP_HEADER_PUBLIC_KEY_PINS_REPORT_ONLY \
    860         "Public-Key-Pins-Report-Only"
    861 /* Permanent.     RFC 4437: Web Distributed Authoring and Versioning (WebDAV) Redirect Reference Resources */
    862 #define MHD_HTTP_HEADER_REDIRECT_REF "Redirect-Ref"
    863 /* Permanent.     HTML */
    864 #define MHD_HTTP_HEADER_REFRESH      "Refresh"
    865 /* Permanent.     RFC 8555, Section 6.5.1: Automatic Certificate Management Environment (ACME) */
    866 #define MHD_HTTP_HEADER_REPLAY_NONCE "Replay-Nonce"
    867 /* Permanent.     RFC-ietf-httpbis-digest-headers-13, Section 3: Digest Fields */
    868 #define MHD_HTTP_HEADER_REPR_DIGEST  "Repr-Digest"
    869 /* Permanent.     RFC 6638: Scheduling Extensions to CalDAV */
    870 #define MHD_HTTP_HEADER_SCHEDULE_REPLY "Schedule-Reply"
    871 /* Permanent.     RFC 6338: Scheduling Extensions to CalDAV */
    872 #define MHD_HTTP_HEADER_SCHEDULE_TAG "Schedule-Tag"
    873 /* Permanent.     Fetch */
    874 #define MHD_HTTP_HEADER_SEC_PURPOSE  "Sec-Purpose"
    875 /* Permanent.     RFC 8473: Token Binding over HTTP */
    876 #define MHD_HTTP_HEADER_SEC_TOKEN_BINDING "Sec-Token-Binding"
    877 /* Permanent.     RFC 6455: The WebSocket Protocol */
    878 #define MHD_HTTP_HEADER_SEC_WEBSOCKET_ACCEPT "Sec-WebSocket-Accept"
    879 /* Permanent.     RFC 6455: The WebSocket Protocol */
    880 #define MHD_HTTP_HEADER_SEC_WEBSOCKET_EXTENSIONS "Sec-WebSocket-Extensions"
    881 /* Permanent.     RFC 6455: The WebSocket Protocol */
    882 #define MHD_HTTP_HEADER_SEC_WEBSOCKET_KEY "Sec-WebSocket-Key"
    883 /* Permanent.     RFC 6455: The WebSocket Protocol */
    884 #define MHD_HTTP_HEADER_SEC_WEBSOCKET_PROTOCOL "Sec-WebSocket-Protocol"
    885 /* Permanent.     RFC 6455: The WebSocket Protocol */
    886 #define MHD_HTTP_HEADER_SEC_WEBSOCKET_VERSION "Sec-WebSocket-Version"
    887 /* Permanent.     Server Timing */
    888 #define MHD_HTTP_HEADER_SERVER_TIMING "Server-Timing"
    889 /* Permanent.     RFC 6265: HTTP State Management Mechanism */
    890 #define MHD_HTTP_HEADER_SET_COOKIE   "Set-Cookie"
    891 /* Permanent.     RFC-ietf-httpbis-message-signatures-19, Section 4.2: HTTP Message Signatures */
    892 #define MHD_HTTP_HEADER_SIGNATURE    "Signature"
    893 /* Permanent.     RFC-ietf-httpbis-message-signatures-19, Section 4.1: HTTP Message Signatures */
    894 #define MHD_HTTP_HEADER_SIGNATURE_INPUT "Signature-Input"
    895 /* Permanent.     RFC 5023: The Atom Publishing Protocol */
    896 #define MHD_HTTP_HEADER_SLUG         "SLUG"
    897 /* Permanent.     Simple Object Access Protocol (SOAP) 1.1 */
    898 #define MHD_HTTP_HEADER_SOAPACTION   "SoapAction"
    899 /* Permanent.     RFC 2518: HTTP Extensions for Distributed Authoring -- WEBDAV */
    900 #define MHD_HTTP_HEADER_STATUS_URI   "Status-URI"
    901 /* Permanent.     RFC 6797: HTTP Strict Transport Security (HSTS) */
    902 #define MHD_HTTP_HEADER_STRICT_TRANSPORT_SECURITY "Strict-Transport-Security"
    903 /* Permanent.     RFC 8594: The Sunset HTTP Header Field */
    904 #define MHD_HTTP_HEADER_SUNSET       "Sunset"
    905 /* Permanent.     Edge Architecture Specification */
    906 #define MHD_HTTP_HEADER_SURROGATE_CAPABILITY "Surrogate-Capability"
    907 /* Permanent.     Edge Architecture Specification */
    908 #define MHD_HTTP_HEADER_SURROGATE_CONTROL "Surrogate-Control"
    909 /* Permanent.     RFC 2295: Transparent Content Negotiation in HTTP */
    910 #define MHD_HTTP_HEADER_TCN          "TCN"
    911 /* Permanent.     RFC 4918: HTTP Extensions for Web Distributed Authoring and Versioning (WebDAV) */
    912 #define MHD_HTTP_HEADER_TIMEOUT      "Timeout"
    913 /* Permanent.     RFC 8030, Section 5.4: Generic Event Delivery Using HTTP Push */
    914 #define MHD_HTTP_HEADER_TOPIC        "Topic"
    915 /* Permanent.     Trace Context */
    916 #define MHD_HTTP_HEADER_TRACEPARENT  "Traceparent"
    917 /* Permanent.     Trace Context */
    918 #define MHD_HTTP_HEADER_TRACESTATE   "Tracestate"
    919 /* Permanent.     RFC 8030, Section 5.2: Generic Event Delivery Using HTTP Push */
    920 #define MHD_HTTP_HEADER_TTL          "TTL"
    921 /* Permanent.     RFC 8030, Section 5.3: Generic Event Delivery Using HTTP Push */
    922 #define MHD_HTTP_HEADER_URGENCY      "Urgency"
    923 /* Permanent.     RFC 2295: Transparent Content Negotiation in HTTP */
    924 #define MHD_HTTP_HEADER_VARIANT_VARY "Variant-Vary"
    925 /* Permanent.     RFC-ietf-httpbis-digest-headers-13, Section 4: Digest Fields */
    926 #define MHD_HTTP_HEADER_WANT_CONTENT_DIGEST "Want-Content-Digest"
    927 /* Permanent.     RFC-ietf-httpbis-digest-headers-13, Section 4: Digest Fields */
    928 #define MHD_HTTP_HEADER_WANT_REPR_DIGEST "Want-Repr-Digest"
    929 /* Permanent.     Fetch */
    930 #define MHD_HTTP_HEADER_X_CONTENT_TYPE_OPTIONS "X-Content-Type-Options"
    931 /* Permanent.     HTML */
    932 #define MHD_HTTP_HEADER_X_FRAME_OPTIONS "X-Frame-Options"
    933 /* Provisional.   AMP-Cache-Transform HTTP request header */
    934 #define MHD_HTTP_HEADER_AMP_CACHE_TRANSFORM "AMP-Cache-Transform"
    935 /* Provisional.   OSLC Configuration Management Version 1.0. Part 3: Configuration Specification */
    936 #define MHD_HTTP_HEADER_CONFIGURATION_CONTEXT "Configuration-Context"
    937 /* Provisional.   RFC 6017: Electronic Data Interchange - Internet Integration (EDIINT) Features Header Field */
    938 #define MHD_HTTP_HEADER_EDIINT_FEATURES "EDIINT-Features"
    939 /* Provisional.   OData Version 4.01 Part 1: Protocol; OASIS; Chet_Ensign */
    940 #define MHD_HTTP_HEADER_ISOLATION    "Isolation"
    941 /* Provisional.   Permissions Policy */
    942 #define MHD_HTTP_HEADER_PERMISSIONS_POLICY "Permissions-Policy"
    943 /* Provisional.   Repeatable Requests Version 1.0; OASIS; Chet_Ensign */
    944 #define MHD_HTTP_HEADER_REPEATABILITY_CLIENT_ID "Repeatability-Client-ID"
    945 /* Provisional.   Repeatable Requests Version 1.0; OASIS; Chet_Ensign */
    946 #define MHD_HTTP_HEADER_REPEATABILITY_FIRST_SENT "Repeatability-First-Sent"
    947 /* Provisional.   Repeatable Requests Version 1.0; OASIS; Chet_Ensign */
    948 #define MHD_HTTP_HEADER_REPEATABILITY_REQUEST_ID "Repeatability-Request-ID"
    949 /* Provisional.   Repeatable Requests Version 1.0; OASIS; Chet_Ensign */
    950 #define MHD_HTTP_HEADER_REPEATABILITY_RESULT "Repeatability-Result"
    951 /* Provisional.   Reporting API */
    952 #define MHD_HTTP_HEADER_REPORTING_ENDPOINTS "Reporting-Endpoints"
    953 /* Provisional.   Global Privacy Control (GPC) */
    954 #define MHD_HTTP_HEADER_SEC_GPC      "Sec-GPC"
    955 /* Provisional.   Resource Timing Level 1 */
    956 #define MHD_HTTP_HEADER_TIMING_ALLOW_ORIGIN "Timing-Allow-Origin"
    957 /* Deprecated.    PEP - an Extension Mechanism for HTTP; status-change-http-experiments-to-historic */
    958 #define MHD_HTTP_HEADER_C_PEP_INFO   "C-PEP-Info"
    959 /* Deprecated.    White Paper: Joint Electronic Payment Initiative */
    960 #define MHD_HTTP_HEADER_PROTOCOL_INFO "Protocol-Info"
    961 /* Deprecated.    White Paper: Joint Electronic Payment Initiative */
    962 #define MHD_HTTP_HEADER_PROTOCOL_QUERY "Protocol-Query"
    963 /* Obsoleted.     Access Control for Cross-site Requests */
    964 #define MHD_HTTP_HEADER_ACCESS_CONTROL "Access-Control"
    965 /* Obsoleted.     RFC 2774: An HTTP Extension Framework; status-change-http-experiments-to-historic */
    966 #define MHD_HTTP_HEADER_C_EXT        "C-Ext"
    967 /* Obsoleted.     RFC 2774: An HTTP Extension Framework; status-change-http-experiments-to-historic */
    968 #define MHD_HTTP_HEADER_C_MAN        "C-Man"
    969 /* Obsoleted.     RFC 2774: An HTTP Extension Framework; status-change-http-experiments-to-historic */
    970 #define MHD_HTTP_HEADER_C_OPT        "C-Opt"
    971 /* Obsoleted.     PEP - an Extension Mechanism for HTTP; status-change-http-experiments-to-historic */
    972 #define MHD_HTTP_HEADER_C_PEP        "C-PEP"
    973 /* Obsoleted.     RFC 2068: Hypertext Transfer Protocol -- HTTP/1.1; RFC 2616: Hypertext Transfer Protocol -- HTTP/1.1 */
    974 #define MHD_HTTP_HEADER_CONTENT_BASE "Content-Base"
    975 /* Obsoleted.     RFC 2616, Section 14.15: Hypertext Transfer Protocol -- HTTP/1.1; RFC 7231, Appendix B: Hypertext Transfer Protocol (HTTP/1.1): Semantics and Content */
    976 #define MHD_HTTP_HEADER_CONTENT_MD5  "Content-MD5"
    977 /* Obsoleted.     HTML 4.01 Specification */
    978 #define MHD_HTTP_HEADER_CONTENT_SCRIPT_TYPE "Content-Script-Type"
    979 /* Obsoleted.     HTML 4.01 Specification */
    980 #define MHD_HTTP_HEADER_CONTENT_STYLE_TYPE "Content-Style-Type"
    981 /* Obsoleted.     RFC 2068: Hypertext Transfer Protocol -- HTTP/1.1 */
    982 #define MHD_HTTP_HEADER_CONTENT_VERSION "Content-Version"
    983 /* Obsoleted.     RFC 2965: HTTP State Management Mechanism; RFC 6265: HTTP State Management Mechanism */
    984 #define MHD_HTTP_HEADER_COOKIE2      "Cookie2"
    985 /* Obsoleted.     HTML 4.01 Specification */
    986 #define MHD_HTTP_HEADER_DEFAULT_STYLE "Default-Style"
    987 /* Obsoleted.     RFC 2068: Hypertext Transfer Protocol -- HTTP/1.1 */
    988 #define MHD_HTTP_HEADER_DERIVED_FROM "Derived-From"
    989 /* Obsoleted.     RFC 3230: Instance Digests in HTTP; RFC-ietf-httpbis-digest-headers-13, Section 1.3: Digest Fields */
    990 #define MHD_HTTP_HEADER_DIGEST       "Digest"
    991 /* Obsoleted.     RFC 2774: An HTTP Extension Framework; status-change-http-experiments-to-historic */
    992 #define MHD_HTTP_HEADER_EXT          "Ext"
    993 /* Obsoleted.     Implementation of OPS Over HTTP */
    994 #define MHD_HTTP_HEADER_GETPROFILE   "GetProfile"
    995 /* Obsoleted.     RFC 7540, Section 3.2.1: Hypertext Transfer Protocol Version 2 (HTTP/2) */
    996 #define MHD_HTTP_HEADER_HTTP2_SETTINGS "HTTP2-Settings"
    997 /* Obsoleted.     RFC 2774: An HTTP Extension Framework; status-change-http-experiments-to-historic */
    998 #define MHD_HTTP_HEADER_MAN          "Man"
    999 /* Obsoleted.     Access Control for Cross-site Requests */
   1000 #define MHD_HTTP_HEADER_METHOD_CHECK "Method-Check"
   1001 /* Obsoleted.     Access Control for Cross-site Requests */
   1002 #define MHD_HTTP_HEADER_METHOD_CHECK_EXPIRES "Method-Check-Expires"
   1003 /* Obsoleted.     RFC 2774: An HTTP Extension Framework; status-change-http-experiments-to-historic */
   1004 #define MHD_HTTP_HEADER_OPT          "Opt"
   1005 /* Obsoleted.     The Platform for Privacy Preferences 1.0 (P3P1.0) Specification */
   1006 #define MHD_HTTP_HEADER_P3P          "P3P"
   1007 /* Obsoleted.     PEP - an Extension Mechanism for HTTP */
   1008 #define MHD_HTTP_HEADER_PEP          "PEP"
   1009 /* Obsoleted.     PEP - an Extension Mechanism for HTTP */
   1010 #define MHD_HTTP_HEADER_PEP_INFO     "Pep-Info"
   1011 /* Obsoleted.     PICS Label Distribution Label Syntax and Communication Protocols */
   1012 #define MHD_HTTP_HEADER_PICS_LABEL   "PICS-Label"
   1013 /* Obsoleted.     Implementation of OPS Over HTTP */
   1014 #define MHD_HTTP_HEADER_PROFILEOBJECT "ProfileObject"
   1015 /* Obsoleted.     PICS Label Distribution Label Syntax and Communication Protocols */
   1016 #define MHD_HTTP_HEADER_PROTOCOL     "Protocol"
   1017 /* Obsoleted.     PICS Label Distribution Label Syntax and Communication Protocols */
   1018 #define MHD_HTTP_HEADER_PROTOCOL_REQUEST "Protocol-Request"
   1019 /* Obsoleted.     Notification for Proxy Caches */
   1020 #define MHD_HTTP_HEADER_PROXY_FEATURES "Proxy-Features"
   1021 /* Obsoleted.     Notification for Proxy Caches */
   1022 #define MHD_HTTP_HEADER_PROXY_INSTRUCTION "Proxy-Instruction"
   1023 /* Obsoleted.     RFC 2068: Hypertext Transfer Protocol -- HTTP/1.1 */
   1024 #define MHD_HTTP_HEADER_PUBLIC       "Public"
   1025 /* Obsoleted.     Access Control for Cross-site Requests */
   1026 #define MHD_HTTP_HEADER_REFERER_ROOT "Referer-Root"
   1027 /* Obsoleted.     RFC 2310: The Safe Response Header Field; status-change-http-experiments-to-historic */
   1028 #define MHD_HTTP_HEADER_SAFE         "Safe"
   1029 /* Obsoleted.     RFC 2660: The Secure HyperText Transfer Protocol; status-change-http-experiments-to-historic */
   1030 #define MHD_HTTP_HEADER_SECURITY_SCHEME "Security-Scheme"
   1031 /* Obsoleted.     RFC 2965: HTTP State Management Mechanism; RFC 6265: HTTP State Management Mechanism */
   1032 #define MHD_HTTP_HEADER_SET_COOKIE2  "Set-Cookie2"
   1033 /* Obsoleted.     Implementation of OPS Over HTTP */
   1034 #define MHD_HTTP_HEADER_SETPROFILE   "SetProfile"
   1035 /* Obsoleted.     RFC 2068: Hypertext Transfer Protocol -- HTTP/1.1 */
   1036 #define MHD_HTTP_HEADER_URI          "URI"
   1037 /* Obsoleted.     RFC 3230: Instance Digests in HTTP; RFC-ietf-httpbis-digest-headers-13, Section 1.3: Digest Fields */
   1038 #define MHD_HTTP_HEADER_WANT_DIGEST  "Want-Digest"
   1039 /* Obsoleted.     RFC9111, Section 5.5: HTTP Caching */
   1040 #define MHD_HTTP_HEADER_WARNING      "Warning"
   1041 
   1042 /* Headers removed from the registry. Do not use! */
   1043 /* Obsoleted.     RFC4229 */
   1044 #define MHD_HTTP_HEADER_COMPLIANCE   "Compliance"
   1045 /* Obsoleted.     RFC4229 */
   1046 #define MHD_HTTP_HEADER_CONTENT_TRANSFER_ENCODING "Content-Transfer-Encoding"
   1047 /* Obsoleted.     RFC4229 */
   1048 #define MHD_HTTP_HEADER_COST         "Cost"
   1049 /* Obsoleted.     RFC4229 */
   1050 #define MHD_HTTP_HEADER_MESSAGE_ID   "Message-ID"
   1051 /* Obsoleted.     RFC4229 */
   1052 #define MHD_HTTP_HEADER_NON_COMPLIANCE "Non-Compliance"
   1053 /* Obsoleted.     RFC4229 */
   1054 #define MHD_HTTP_HEADER_OPTIONAL     "Optional"
   1055 /* Obsoleted.     RFC4229 */
   1056 #define MHD_HTTP_HEADER_RESOLUTION_HINT "Resolution-Hint"
   1057 /* Obsoleted.     RFC4229 */
   1058 #define MHD_HTTP_HEADER_RESOLVER_LOCATION "Resolver-Location"
   1059 /* Obsoleted.     RFC4229 */
   1060 #define MHD_HTTP_HEADER_SUBOK        "SubOK"
   1061 /* Obsoleted.     RFC4229 */
   1062 #define MHD_HTTP_HEADER_SUBST        "Subst"
   1063 /* Obsoleted.     RFC4229 */
   1064 #define MHD_HTTP_HEADER_TITLE        "Title"
   1065 /* Obsoleted.     RFC4229 */
   1066 #define MHD_HTTP_HEADER_UA_COLOR     "UA-Color"
   1067 /* Obsoleted.     RFC4229 */
   1068 #define MHD_HTTP_HEADER_UA_MEDIA     "UA-Media"
   1069 /* Obsoleted.     RFC4229 */
   1070 #define MHD_HTTP_HEADER_UA_PIXELS    "UA-Pixels"
   1071 /* Obsoleted.     RFC4229 */
   1072 #define MHD_HTTP_HEADER_UA_RESOLUTION "UA-Resolution"
   1073 /* Obsoleted.     RFC4229 */
   1074 #define MHD_HTTP_HEADER_UA_WINDOWPIXELS "UA-Windowpixels"
   1075 /* Obsoleted.     RFC4229 */
   1076 #define MHD_HTTP_HEADER_VERSION      "Version"
   1077 /* Obsoleted.     W3C Mobile Web Best Practices Working Group */
   1078 #define MHD_HTTP_HEADER_X_DEVICE_ACCEPT "X-Device-Accept"
   1079 /* Obsoleted.     W3C Mobile Web Best Practices Working Group */
   1080 #define MHD_HTTP_HEADER_X_DEVICE_ACCEPT_CHARSET "X-Device-Accept-Charset"
   1081 /* Obsoleted.     W3C Mobile Web Best Practices Working Group */
   1082 #define MHD_HTTP_HEADER_X_DEVICE_ACCEPT_ENCODING "X-Device-Accept-Encoding"
   1083 /* Obsoleted.     W3C Mobile Web Best Practices Working Group */
   1084 #define MHD_HTTP_HEADER_X_DEVICE_ACCEPT_LANGUAGE "X-Device-Accept-Language"
   1085 /* Obsoleted.     W3C Mobile Web Best Practices Working Group */
   1086 #define MHD_HTTP_HEADER_X_DEVICE_USER_AGENT "X-Device-User-Agent"
   1087 
   1088 /** @} */ /* end of group headers */
   1089 
   1090 /**
   1091  * @defgroup versions HTTP versions
   1092  * These strings should be used to match against the first line of the
   1093  * HTTP header.
   1094  * @{
   1095  */
   1096 #define MHD_HTTP_VERSION_1_0 "HTTP/1.0"
   1097 #define MHD_HTTP_VERSION_1_1 "HTTP/1.1"
   1098 
   1099 /** @} */ /* end of group versions */
   1100 
   1101 /**
   1102  * @defgroup methods HTTP methods
   1103  * HTTP methods (as strings).
   1104  * See: https://www.iana.org/assignments/http-methods/http-methods.xml
   1105  * Registry export date: 2023-10-02
   1106  * @{
   1107  */
   1108 
   1109 /* Main HTTP methods. */
   1110 /* Safe.     Idempotent.     RFC9110, Section 9.3.1. */
   1111 #define MHD_HTTP_METHOD_GET      "GET"
   1112 /* Safe.     Idempotent.     RFC9110, Section 9.3.2. */
   1113 #define MHD_HTTP_METHOD_HEAD     "HEAD"
   1114 /* Not safe. Not idempotent. RFC9110, Section 9.3.3. */
   1115 #define MHD_HTTP_METHOD_POST     "POST"
   1116 /* Not safe. Idempotent.     RFC9110, Section 9.3.4. */
   1117 #define MHD_HTTP_METHOD_PUT      "PUT"
   1118 /* Not safe. Idempotent.     RFC9110, Section 9.3.5. */
   1119 #define MHD_HTTP_METHOD_DELETE   "DELETE"
   1120 /* Not safe. Not idempotent. RFC9110, Section 9.3.6. */
   1121 #define MHD_HTTP_METHOD_CONNECT  "CONNECT"
   1122 /* Safe.     Idempotent.     RFC9110, Section 9.3.7. */
   1123 #define MHD_HTTP_METHOD_OPTIONS  "OPTIONS"
   1124 /* Safe.     Idempotent.     RFC9110, Section 9.3.8. */
   1125 #define MHD_HTTP_METHOD_TRACE    "TRACE"
   1126 
   1127 /* Additional HTTP methods. */
   1128 /* Not safe. Idempotent.     RFC3744, Section 8.1. */
   1129 #define MHD_HTTP_METHOD_ACL            "ACL"
   1130 /* Not safe. Idempotent.     RFC3253, Section 12.6. */
   1131 #define MHD_HTTP_METHOD_BASELINE_CONTROL "BASELINE-CONTROL"
   1132 /* Not safe. Idempotent.     RFC5842, Section 4. */
   1133 #define MHD_HTTP_METHOD_BIND           "BIND"
   1134 /* Not safe. Idempotent.     RFC3253, Section 4.4, Section 9.4. */
   1135 #define MHD_HTTP_METHOD_CHECKIN        "CHECKIN"
   1136 /* Not safe. Idempotent.     RFC3253, Section 4.3, Section 8.8. */
   1137 #define MHD_HTTP_METHOD_CHECKOUT       "CHECKOUT"
   1138 /* Not safe. Idempotent.     RFC4918, Section 9.8. */
   1139 #define MHD_HTTP_METHOD_COPY           "COPY"
   1140 /* Not safe. Idempotent.     RFC3253, Section 8.2. */
   1141 #define MHD_HTTP_METHOD_LABEL          "LABEL"
   1142 /* Not safe. Idempotent.     RFC2068, Section 19.6.1.2. */
   1143 #define MHD_HTTP_METHOD_LINK           "LINK"
   1144 /* Not safe. Not idempotent. RFC4918, Section 9.10. */
   1145 #define MHD_HTTP_METHOD_LOCK           "LOCK"
   1146 /* Not safe. Idempotent.     RFC3253, Section 11.2. */
   1147 #define MHD_HTTP_METHOD_MERGE          "MERGE"
   1148 /* Not safe. Idempotent.     RFC3253, Section 13.5. */
   1149 #define MHD_HTTP_METHOD_MKACTIVITY     "MKACTIVITY"
   1150 /* Not safe. Idempotent.     RFC4791, Section 5.3.1; RFC8144, Section 2.3. */
   1151 #define MHD_HTTP_METHOD_MKCALENDAR     "MKCALENDAR"
   1152 /* Not safe. Idempotent.     RFC4918, Section 9.3; RFC5689, Section 3; RFC8144, Section 2.3. */
   1153 #define MHD_HTTP_METHOD_MKCOL          "MKCOL"
   1154 /* Not safe. Idempotent.     RFC4437, Section 6. */
   1155 #define MHD_HTTP_METHOD_MKREDIRECTREF  "MKREDIRECTREF"
   1156 /* Not safe. Idempotent.     RFC3253, Section 6.3. */
   1157 #define MHD_HTTP_METHOD_MKWORKSPACE    "MKWORKSPACE"
   1158 /* Not safe. Idempotent.     RFC4918, Section 9.9. */
   1159 #define MHD_HTTP_METHOD_MOVE           "MOVE"
   1160 /* Not safe. Idempotent.     RFC3648, Section 7. */
   1161 #define MHD_HTTP_METHOD_ORDERPATCH     "ORDERPATCH"
   1162 /* Not safe. Not idempotent. RFC5789, Section 2. */
   1163 #define MHD_HTTP_METHOD_PATCH          "PATCH"
   1164 /* Safe.     Idempotent.     RFC9113, Section 3.4. */
   1165 #define MHD_HTTP_METHOD_PRI            "PRI"
   1166 /* Safe.     Idempotent.     RFC4918, Section 9.1; RFC8144, Section 2.1. */
   1167 #define MHD_HTTP_METHOD_PROPFIND       "PROPFIND"
   1168 /* Not safe. Idempotent.     RFC4918, Section 9.2; RFC8144, Section 2.2. */
   1169 #define MHD_HTTP_METHOD_PROPPATCH      "PROPPATCH"
   1170 /* Not safe. Idempotent.     RFC5842, Section 6. */
   1171 #define MHD_HTTP_METHOD_REBIND         "REBIND"
   1172 /* Safe.     Idempotent.     RFC3253, Section 3.6; RFC8144, Section 2.1. */
   1173 #define MHD_HTTP_METHOD_REPORT         "REPORT"
   1174 /* Safe.     Idempotent.     RFC5323, Section 2. */
   1175 #define MHD_HTTP_METHOD_SEARCH         "SEARCH"
   1176 /* Not safe. Idempotent.     RFC5842, Section 5. */
   1177 #define MHD_HTTP_METHOD_UNBIND         "UNBIND"
   1178 /* Not safe. Idempotent.     RFC3253, Section 4.5. */
   1179 #define MHD_HTTP_METHOD_UNCHECKOUT     "UNCHECKOUT"
   1180 /* Not safe. Idempotent.     RFC2068, Section 19.6.1.3. */
   1181 #define MHD_HTTP_METHOD_UNLINK         "UNLINK"
   1182 /* Not safe. Idempotent.     RFC4918, Section 9.11. */
   1183 #define MHD_HTTP_METHOD_UNLOCK         "UNLOCK"
   1184 /* Not safe. Idempotent.     RFC3253, Section 7.1. */
   1185 #define MHD_HTTP_METHOD_UPDATE         "UPDATE"
   1186 /* Not safe. Idempotent.     RFC4437, Section 7. */
   1187 #define MHD_HTTP_METHOD_UPDATEREDIRECTREF "UPDATEREDIRECTREF"
   1188 /* Not safe. Idempotent.     RFC3253, Section 3.5. */
   1189 #define MHD_HTTP_METHOD_VERSION_CONTROL "VERSION-CONTROL"
   1190 /* Not safe. Not idempotent. RFC9110, Section 18.2. */
   1191 #define MHD_HTTP_METHOD_ASTERISK       "*"
   1192 
   1193 /** @} */ /* end of group methods */
   1194 
   1195 /**
   1196  * @defgroup postenc HTTP POST encodings
   1197  * See also: http://www.w3.org/TR/html4/interact/forms.html#h-17.13.4
   1198  * @{
   1199  */
   1200 #define MHD_HTTP_POST_ENCODING_FORM_URLENCODED \
   1201         "application/x-www-form-urlencoded"
   1202 #define MHD_HTTP_POST_ENCODING_MULTIPART_FORMDATA "multipart/form-data"
   1203 
   1204 /** @} */ /* end of group postenc */
   1205 
   1206 
   1207 /**
   1208  * @brief Handle for the daemon (listening on a socket for HTTP traffic).
   1209  * @ingroup event
   1210  */
   1211 struct MHD_Daemon;
   1212 
   1213 /**
   1214  * @brief Handle for a connection / HTTP request.
   1215  *
   1216  * With HTTP/1.1, multiple requests can be run over the same
   1217  * connection.  However, MHD will only show one request per TCP
   1218  * connection to the client at any given time.
   1219  * @ingroup request
   1220  */
   1221 struct MHD_Connection;
   1222 
   1223 /**
   1224  * @brief Handle for a response.
   1225  * @ingroup response
   1226  */
   1227 struct MHD_Response;
   1228 
   1229 /**
   1230  * @brief Handle for POST processing.
   1231  * @ingroup response
   1232  */
   1233 struct MHD_PostProcessor;
   1234 
   1235 
   1236 /**
   1237  * @brief Flags for the `struct MHD_Daemon`.
   1238  *
   1239  * Note that MHD will run automatically in background thread(s) only
   1240  * if #MHD_USE_INTERNAL_POLLING_THREAD is used. Otherwise caller (application)
   1241  * must use #MHD_run() or #MHD_run_from_select() to have MHD processed
   1242  * network connections and data.
   1243  *
   1244  * Starting the daemon may also fail if a particular option is not
   1245  * implemented or not supported on the target platform (i.e. no
   1246  * support for TLS, epoll or IPv6).
   1247  */
   1248 enum MHD_FLAG
   1249 {
   1250   /**
   1251    * No options selected.
   1252    */
   1253   MHD_NO_FLAG = 0,
   1254 
   1255   /**
   1256    * Print errors messages to custom error logger or to `stderr` if
   1257    * custom error logger is not set.
   1258    * @sa ::MHD_OPTION_EXTERNAL_LOGGER
   1259    */
   1260   MHD_USE_ERROR_LOG = 1,
   1261 
   1262   /**
   1263    * Run in debug mode.  If this flag is used, the library should
   1264    * print error messages and warnings to `stderr`.
   1265    */
   1266   MHD_USE_DEBUG = 1,
   1267 
   1268   /**
   1269    * Run in HTTPS mode.  The modern protocol is called TLS.
   1270    */
   1271   MHD_USE_TLS = 2,
   1272 
   1273   /** @deprecated */
   1274   MHD_USE_SSL = 2,
   1275 #if 0
   1276   /* let's do this later once versions that define MHD_USE_TLS a more widely deployed. */
   1277 #define MHD_USE_SSL \
   1278         _MHD_DEPR_IN_MACRO ("Value MHD_USE_SSL is deprecated, use MHD_USE_TLS") \
   1279         MHD_USE_TLS
   1280 #endif
   1281 
   1282   /**
   1283    * Run using one thread per connection.
   1284    * Must be used only with #MHD_USE_INTERNAL_POLLING_THREAD.
   1285    *
   1286    * If #MHD_USE_ITC is also not used, closed and expired connections may only
   1287    * be cleaned up internally when a new connection is received.
   1288    * Consider adding of #MHD_USE_ITC flag to have faster internal cleanups
   1289    * at very minor increase in system resources usage.
   1290    */
   1291   MHD_USE_THREAD_PER_CONNECTION = 4,
   1292 
   1293   /**
   1294    * Run using an internal thread (or thread pool) for sockets sending
   1295    * and receiving and data processing. Without this flag MHD will not
   1296    * run automatically in background thread(s).
   1297    * If this flag is set, #MHD_run() and #MHD_run_from_select() couldn't
   1298    * be used.
   1299    * This flag is set explicitly by #MHD_USE_POLL_INTERNAL_THREAD and
   1300    * by #MHD_USE_EPOLL_INTERNAL_THREAD.
   1301    * When this flag is not set, MHD run in "external" polling mode.
   1302    */
   1303   MHD_USE_INTERNAL_POLLING_THREAD = 8,
   1304 
   1305   /** @deprecated */
   1306   MHD_USE_SELECT_INTERNALLY = 8,
   1307 #if 0 /* Will be marked for real deprecation later. */
   1308 #define MHD_USE_SELECT_INTERNALLY \
   1309         _MHD_DEPR_IN_MACRO ( \
   1310           "Value MHD_USE_SELECT_INTERNALLY is deprecated, use MHD_USE_INTERNAL_POLLING_THREAD instead") \
   1311         MHD_USE_INTERNAL_POLLING_THREAD
   1312 #endif /* 0 */
   1313 
   1314   /**
   1315    * Run using the IPv6 protocol (otherwise, MHD will just support
   1316    * IPv4).  If you want MHD to support IPv4 and IPv6 using a single
   1317    * socket, pass #MHD_USE_DUAL_STACK, otherwise, if you only pass
   1318    * this option, MHD will try to bind to IPv6-only (resulting in
   1319    * no IPv4 support).
   1320    */
   1321   MHD_USE_IPv6 = 16,
   1322 
   1323   /**
   1324    * Be pedantic about the protocol (as opposed to as tolerant as
   1325    * possible).
   1326    * This flag is equivalent to setting 1 as #MHD_OPTION_CLIENT_DISCIPLINE_LVL
   1327    * value.
   1328    * @sa #MHD_OPTION_CLIENT_DISCIPLINE_LVL
   1329    */
   1330   MHD_USE_PEDANTIC_CHECKS = 32,
   1331 #if 0 /* Will be marked for real deprecation later. */
   1332 #define MHD_USE_PEDANTIC_CHECKS \
   1333         _MHD_DEPR_IN_MACRO ( \
   1334           "Flag MHD_USE_PEDANTIC_CHECKS is deprecated, " \
   1335           "use option MHD_OPTION_CLIENT_DISCIPLINE_LVL instead") \
   1336         32
   1337 #endif /* 0 */
   1338 
   1339   /**
   1340    * Use `poll()` instead of `select()` for polling sockets.
   1341    * This allows sockets with `fd >= FD_SETSIZE`.
   1342    * This option is not compatible with an "external" polling mode
   1343    * (as there is no API to get the file descriptors for the external
   1344    * poll() from MHD) and must also not be used in combination
   1345    * with #MHD_USE_EPOLL.
   1346    * @sa ::MHD_FEATURE_POLL, #MHD_USE_POLL_INTERNAL_THREAD
   1347    */
   1348   MHD_USE_POLL = 64,
   1349 
   1350   /**
   1351    * Run using an internal thread (or thread pool) doing `poll()`.
   1352    * @sa ::MHD_FEATURE_POLL, #MHD_USE_POLL, #MHD_USE_INTERNAL_POLLING_THREAD
   1353    */
   1354   MHD_USE_POLL_INTERNAL_THREAD = MHD_USE_POLL | MHD_USE_INTERNAL_POLLING_THREAD,
   1355 
   1356   /** @deprecated */
   1357   MHD_USE_POLL_INTERNALLY = MHD_USE_POLL | MHD_USE_INTERNAL_POLLING_THREAD,
   1358 #if 0 /* Will be marked for real deprecation later. */
   1359 #define MHD_USE_POLL_INTERNALLY \
   1360         _MHD_DEPR_IN_MACRO ( \
   1361           "Value MHD_USE_POLL_INTERNALLY is deprecated, use MHD_USE_POLL_INTERNAL_THREAD instead") \
   1362         MHD_USE_POLL_INTERNAL_THREAD
   1363 #endif /* 0 */
   1364 
   1365   /**
   1366    * Suppress (automatically) adding the 'Date:' header to HTTP responses.
   1367    * This option should ONLY be used on systems that do not have a clock
   1368    * and that DO provide other mechanisms for cache control.  See also
   1369    * RFC 2616, section 14.18 (exception 3).
   1370    */
   1371   MHD_USE_SUPPRESS_DATE_NO_CLOCK = 128,
   1372 
   1373   /** @deprecated */
   1374   MHD_SUPPRESS_DATE_NO_CLOCK = 128,
   1375 #if 0 /* Will be marked for real deprecation later. */
   1376 #define MHD_SUPPRESS_DATE_NO_CLOCK \
   1377         _MHD_DEPR_IN_MACRO ( \
   1378           "Value MHD_SUPPRESS_DATE_NO_CLOCK is deprecated, use MHD_USE_SUPPRESS_DATE_NO_CLOCK instead") \
   1379         MHD_USE_SUPPRESS_DATE_NO_CLOCK
   1380 #endif /* 0 */
   1381 
   1382   /**
   1383    * Run without a listen socket.  This option only makes sense if
   1384    * #MHD_add_connection is to be used exclusively to connect HTTP
   1385    * clients to the HTTP server.  This option is incompatible with
   1386    * using a thread pool; if it is used, #MHD_OPTION_THREAD_POOL_SIZE
   1387    * is ignored.
   1388    */
   1389   MHD_USE_NO_LISTEN_SOCKET = 256,
   1390 
   1391   /**
   1392    * Use `epoll()` instead of `select()` or `poll()` for the event loop.
   1393    * This option is only available on some systems; using the option on
   1394    * systems without epoll will cause #MHD_start_daemon to fail.  Using
   1395    * this option is not supported with #MHD_USE_THREAD_PER_CONNECTION.
   1396    * @sa ::MHD_FEATURE_EPOLL
   1397    */
   1398   MHD_USE_EPOLL = 512,
   1399 
   1400   /** @deprecated */
   1401   MHD_USE_EPOLL_LINUX_ONLY = 512,
   1402 #if 0 /* Will be marked for real deprecation later. */
   1403 #define MHD_USE_EPOLL_LINUX_ONLY \
   1404         _MHD_DEPR_IN_MACRO ( \
   1405           "Value MHD_USE_EPOLL_LINUX_ONLY is deprecated, use MHD_USE_EPOLL") \
   1406         MHD_USE_EPOLL
   1407 #endif /* 0 */
   1408 
   1409   /**
   1410    * Run using an internal thread (or thread pool) doing `epoll` polling.
   1411    * This option is only available on certain platforms; using the option on
   1412    * platform without `epoll` support will cause #MHD_start_daemon to fail.
   1413    * @sa ::MHD_FEATURE_EPOLL, #MHD_USE_EPOLL, #MHD_USE_INTERNAL_POLLING_THREAD
   1414    */
   1415   MHD_USE_EPOLL_INTERNAL_THREAD = MHD_USE_EPOLL
   1416                                   | MHD_USE_INTERNAL_POLLING_THREAD,
   1417 
   1418   /** @deprecated */
   1419   MHD_USE_EPOLL_INTERNALLY = MHD_USE_EPOLL | MHD_USE_INTERNAL_POLLING_THREAD,
   1420   /** @deprecated */
   1421   MHD_USE_EPOLL_INTERNALLY_LINUX_ONLY = MHD_USE_EPOLL
   1422                                         | MHD_USE_INTERNAL_POLLING_THREAD,
   1423 #if 0 /* Will be marked for real deprecation later. */
   1424 #define MHD_USE_EPOLL_INTERNALLY \
   1425         _MHD_DEPR_IN_MACRO ( \
   1426           "Value MHD_USE_EPOLL_INTERNALLY is deprecated, use MHD_USE_EPOLL_INTERNAL_THREAD") \
   1427         MHD_USE_EPOLL_INTERNAL_THREAD
   1428   /** @deprecated */
   1429 #define MHD_USE_EPOLL_INTERNALLY_LINUX_ONLY \
   1430         _MHD_DEPR_IN_MACRO ( \
   1431           "Value MHD_USE_EPOLL_INTERNALLY_LINUX_ONLY is deprecated, use MHD_USE_EPOLL_INTERNAL_THREAD") \
   1432         MHD_USE_EPOLL_INTERNAL_THREAD
   1433 #endif /* 0 */
   1434 
   1435   /**
   1436    * Use inter-thread communication channel.
   1437    * #MHD_USE_ITC can be used with #MHD_USE_INTERNAL_POLLING_THREAD
   1438    * and is ignored with any "external" sockets polling.
   1439    * It's required for use of #MHD_quiesce_daemon
   1440    * or #MHD_add_connection.
   1441    * This option is enforced by #MHD_ALLOW_SUSPEND_RESUME or
   1442    * #MHD_USE_NO_LISTEN_SOCKET.
   1443    * Note that while this flag has no effect of its own with "external"
   1444    * sockets polling, the channel implied by #MHD_ALLOW_SUSPEND_RESUME
   1445    * is created and used in that mode as well: #MHD_get_fdset() adds it
   1446    * to the read set, so that #MHD_resume_connection() called from
   1447    * another thread interrupts a blocking select()/poll() of the
   1448    * application.  See #MHD_resume_connection().
   1449    * #MHD_USE_ITC is always used automatically on platforms
   1450    * where select()/poll()/other ignore shutdown of listen
   1451    * socket.
   1452    */
   1453   MHD_USE_ITC = 1024,
   1454 
   1455   /** @deprecated */
   1456   MHD_USE_PIPE_FOR_SHUTDOWN = 1024,
   1457 #if 0 /* Will be marked for real deprecation later. */
   1458 #define MHD_USE_PIPE_FOR_SHUTDOWN \
   1459         _MHD_DEPR_IN_MACRO ( \
   1460           "Value MHD_USE_PIPE_FOR_SHUTDOWN is deprecated, use MHD_USE_ITC") \
   1461         MHD_USE_ITC
   1462 #endif /* 0 */
   1463 
   1464   /**
   1465    * Use a single socket for IPv4 and IPv6.
   1466    */
   1467   MHD_USE_DUAL_STACK = MHD_USE_IPv6 | 2048,
   1468 
   1469   /**
   1470    * Enable `turbo`.  Disables certain calls to `shutdown()`,
   1471    * enables aggressive non-blocking optimistic reads and
   1472    * other potentially unsafe optimizations.
   1473    * Most effects only happen with #MHD_USE_EPOLL.
   1474    */
   1475   MHD_USE_TURBO = 4096,
   1476 
   1477   /** @deprecated */
   1478   MHD_USE_EPOLL_TURBO = 4096,
   1479 #if 0 /* Will be marked for real deprecation later. */
   1480 #define MHD_USE_EPOLL_TURBO \
   1481         _MHD_DEPR_IN_MACRO ( \
   1482           "Value MHD_USE_EPOLL_TURBO is deprecated, use MHD_USE_TURBO") \
   1483         MHD_USE_TURBO
   1484 #endif /* 0 */
   1485 
   1486   /**
   1487    * Enable suspend/resume functions, which also implies setting up
   1488    * ITC to signal resume.
   1489    */
   1490   MHD_ALLOW_SUSPEND_RESUME = 8192 | MHD_USE_ITC,
   1491 
   1492   /** @deprecated */
   1493   MHD_USE_SUSPEND_RESUME = 8192 | MHD_USE_ITC,
   1494 #if 0 /* Will be marked for real deprecation later. */
   1495 #define MHD_USE_SUSPEND_RESUME \
   1496         _MHD_DEPR_IN_MACRO ( \
   1497           "Value MHD_USE_SUSPEND_RESUME is deprecated, use MHD_ALLOW_SUSPEND_RESUME instead") \
   1498         MHD_ALLOW_SUSPEND_RESUME
   1499 #endif /* 0 */
   1500 
   1501   /**
   1502    * Enable TCP_FASTOPEN option.  This option is only available on Linux with a
   1503    * kernel >= 3.6.  On other systems, using this option cases #MHD_start_daemon
   1504    * to fail.
   1505    */
   1506   MHD_USE_TCP_FASTOPEN = 16384,
   1507 
   1508   /**
   1509    * You need to set this option if you want to use HTTP "Upgrade".
   1510    * "Upgrade" may require usage of additional internal resources,
   1511    * which we do not want to use unless necessary.
   1512    */
   1513   MHD_ALLOW_UPGRADE = 32768,
   1514 
   1515   /**
   1516    * Automatically use best available polling function.
   1517    * Choice of polling function is also depend on other daemon options.
   1518    * If #MHD_USE_INTERNAL_POLLING_THREAD is specified then epoll, poll() or
   1519    * select() will be used (listed in decreasing preference order, first
   1520    * function available on system will be used).
   1521    * If #MHD_USE_THREAD_PER_CONNECTION is specified then poll() or select()
   1522    * will be used.
   1523    * If those flags are not specified then epoll or select() will be
   1524    * used (as the only suitable for MHD_get_fdset())
   1525    */
   1526   MHD_USE_AUTO = 65536,
   1527 
   1528   /**
   1529    * Run using an internal thread (or thread pool) with best available on
   1530    * system polling function.
   1531    * This is combination of #MHD_USE_AUTO and #MHD_USE_INTERNAL_POLLING_THREAD
   1532    * flags.
   1533    */
   1534   MHD_USE_AUTO_INTERNAL_THREAD = MHD_USE_AUTO | MHD_USE_INTERNAL_POLLING_THREAD,
   1535 
   1536   /**
   1537    * Flag set to enable post-handshake client authentication
   1538    * (only useful in combination with #MHD_USE_TLS).
   1539    */
   1540   MHD_USE_POST_HANDSHAKE_AUTH_SUPPORT = 1U << 17,
   1541 
   1542   /**
   1543    * Flag set to enable TLS 1.3 early data.  This has
   1544    * security implications, be VERY careful when using this.
   1545    */
   1546   MHD_USE_INSECURE_TLS_EARLY_DATA = 1U << 18,
   1547 
   1548   /**
   1549    * Indicates that MHD daemon will be used by application in single-threaded
   1550    * mode only.  When this flag is set then application must call any MHD
   1551    * function only within a single thread.
   1552    * This flag turns off some internal thread-safety and allows MHD making
   1553    * some of the internal optimisations suitable only for single-threaded
   1554    * environment.
   1555    * Not compatible with #MHD_USE_INTERNAL_POLLING_THREAD.
   1556    * @note Available since #MHD_VERSION 0x00097707
   1557    */
   1558   MHD_USE_NO_THREAD_SAFETY = 1U << 19
   1559 
   1560 };
   1561 
   1562 
   1563 /**
   1564  * Type of a callback function used for logging by MHD.
   1565  *
   1566  * @param cls closure
   1567  * @param fm format string (`printf()`-style)
   1568  * @param ap arguments to @a fm
   1569  * @ingroup logging
   1570  */
   1571 typedef void
   1572 (*MHD_LogCallback)(void *cls,
   1573                    const char *fm,
   1574                    va_list ap);
   1575 
   1576 
   1577 /**
   1578  * Function called to lookup the pre shared key (@a psk) for a given
   1579  * HTTP connection based on the @a username.
   1580  *
   1581  * @param cls closure
   1582  * @param connection the HTTPS connection
   1583  * @param username the user name claimed by the other side
   1584  * @param[out] psk to be set to the pre-shared-key; should be allocated with malloc(),
   1585  *                 will be freed by MHD
   1586  * @param[out] psk_size to be set to the number of bytes in @a psk
   1587  * @return 0 on success, -1 on errors
   1588  */
   1589 typedef int
   1590 (*MHD_PskServerCredentialsCallback)(void *cls,
   1591                                     const struct MHD_Connection *connection,
   1592                                     const char *username,
   1593                                     void **psk,
   1594                                     size_t *psk_size);
   1595 
   1596 /**
   1597  * Values for #MHD_OPTION_DIGEST_AUTH_NONCE_BIND_TYPE.
   1598  *
   1599  * These values can limit the scope of validity of MHD-generated nonces.
   1600  * Values can be combined with bitwise OR.
   1601  * Any value, except #MHD_DAUTH_BIND_NONCE_NONE, enforce function
   1602  * #MHD_digest_auth_check3() (and similar functions) to check nonce by
   1603  * re-generating it again with the same parameters, which is CPU-intensive
   1604  * operation.
   1605  * @note Available since #MHD_VERSION 0x00097701
   1606  */
   1607 enum MHD_DAuthBindNonce
   1608 {
   1609   /**
   1610    * Generated nonces are valid for any request from any client until expired.
   1611    * This is default and recommended value.
   1612    * #MHD_digest_auth_check3() (and similar functions) would check only whether
   1613    * the nonce value that is used by client has been generated by MHD and not
   1614    * expired yet.
   1615    * It is recommended because RFC 7616 allows clients to use the same nonce
   1616    * for any request in the same "protection space".
   1617    * When checking client's authorisation requests CPU is loaded less if this
   1618    * value is used.
   1619    * This mode gives MHD maximum flexibility for nonces generation and can
   1620    * prevent possible nonce collisions (and corresponding log warning messages)
   1621    * when clients' requests are intensive.
   1622    * This value cannot be biwise-OR combined with other values.
   1623    */
   1624   MHD_DAUTH_BIND_NONCE_NONE = 0,
   1625 
   1626   /**
   1627    * Generated nonces are valid only for the same realm.
   1628    */
   1629   MHD_DAUTH_BIND_NONCE_REALM = 1 << 0,
   1630 
   1631   /**
   1632    * Generated nonces are valid only for the same URI (excluding parameters
   1633    * after '?' in URI) and request method (GET, POST etc).
   1634    * Not recommended unless "protection space" is limited to a single URI as
   1635    * RFC 7616 allows clients to re-use server-generated nonces for any URI
   1636    * in the same "protection space" which by default consists of all server
   1637    * URIs.
   1638    * Before #MHD_VERSION 0x00097701 this was default (and only supported)
   1639    * nonce bind type.
   1640    */
   1641   MHD_DAUTH_BIND_NONCE_URI = 1 << 1,
   1642 
   1643   /**
   1644    * Generated nonces are valid only for the same URI including URI parameters
   1645    * and request method (GET, POST etc).
   1646    * This value implies #MHD_DAUTH_BIND_NONCE_URI.
   1647    * Not recommended for that same reasons as #MHD_DAUTH_BIND_NONCE_URI.
   1648    */
   1649   MHD_DAUTH_BIND_NONCE_URI_PARAMS = 1 << 2,
   1650 
   1651   /**
   1652    * Generated nonces are valid only for the single client's IP.
   1653    * While it looks like security improvement, in practice the same client may
   1654    * jump from one IP to another (mobile or Wi-Fi handover, DHCP re-assignment,
   1655    * Multi-NAT, different proxy chain and other reasons), while IP address
   1656    * spoofing could be used relatively easily.
   1657    */
   1658   MHD_DAUTH_BIND_NONCE_CLIENT_IP = 1 << 3
   1659 } _MHD_FLAGS_ENUM;
   1660 
   1661 /**
   1662  * @brief MHD options.
   1663  *
   1664  * Passed in the varargs portion of #MHD_start_daemon.
   1665  */
   1666 enum MHD_OPTION
   1667 {
   1668 
   1669   /**
   1670    * No more options / last option.  This is used
   1671    * to terminate the VARARGs list.
   1672    */
   1673   MHD_OPTION_END = 0,
   1674 
   1675   /**
   1676    * Maximum memory size per connection (followed by a `size_t`).
   1677    * Default is 32 kb (#MHD_POOL_SIZE_DEFAULT).
   1678    * Values above 128k are unlikely to result in much benefit, as half
   1679    * of the memory will be typically used for IO, and TCP buffers are
   1680    * unlikely to support window sizes above 64k on most systems.
   1681    * Values below 64 bytes are completely unusable.
   1682    * Since #MHD_VERSION 0x00097710 silently ignored if followed by zero value.
   1683    */
   1684   MHD_OPTION_CONNECTION_MEMORY_LIMIT = 1,
   1685 
   1686   /**
   1687    * Maximum number of concurrent connections to
   1688    * accept (followed by an `unsigned int`).
   1689    */
   1690   MHD_OPTION_CONNECTION_LIMIT = 2,
   1691 
   1692   /**
   1693    * After how many seconds of inactivity should a
   1694    * connection automatically be timed out? (followed
   1695    * by an `unsigned int`; use zero for no timeout).
   1696    * Values larger than (UINT64_MAX / 2000 - 1) will
   1697    * be clipped to this number.
   1698    */
   1699   MHD_OPTION_CONNECTION_TIMEOUT = 3,
   1700 
   1701   /**
   1702    * Register a function that should be called whenever a request has
   1703    * been completed (this can be used for application-specific clean
   1704    * up).  Requests that have never been presented to the application
   1705    * (via #MHD_AccessHandlerCallback) will not result in
   1706    * notifications.
   1707    *
   1708    * This option should be followed by TWO pointers.  First a pointer
   1709    * to a function of type #MHD_RequestCompletedCallback and second a
   1710    * pointer to a closure to pass to the request completed callback.
   1711    * The second pointer may be NULL.
   1712    */
   1713   MHD_OPTION_NOTIFY_COMPLETED = 4,
   1714 
   1715   /**
   1716    * Limit on the number of (concurrent) connections made to the
   1717    * server from the same IP address.  Can be used to prevent one
   1718    * IP from taking over all of the allowed connections.  If the
   1719    * same IP tries to establish more than the specified number of
   1720    * connections, they will be immediately rejected.  The option
   1721    * should be followed by an `unsigned int`.  The default is
   1722    * zero, which means no limit on the number of connections
   1723    * from the same IP address.
   1724    */
   1725   MHD_OPTION_PER_IP_CONNECTION_LIMIT = 5,
   1726 
   1727   /**
   1728    * Bind daemon to the supplied `struct sockaddr`. This option should
   1729    * be followed by a `struct sockaddr *`.  If #MHD_USE_IPv6 is
   1730    * specified, the `struct sockaddr*` should point to a `struct
   1731    * sockaddr_in6`, otherwise to a `struct sockaddr_in`.
   1732    * Silently ignored if followed by NULL pointer.
   1733    * @deprecated Use #MHD_OPTION_SOCK_ADDR_LEN
   1734    */
   1735   MHD_OPTION_SOCK_ADDR = 6,
   1736 
   1737   /**
   1738    * Specify a function that should be called before parsing the URI from
   1739    * the client.  The specified callback function can be used for processing
   1740    * the URI (including the options) before it is parsed.  The URI after
   1741    * parsing will no longer contain the options, which maybe inconvenient for
   1742    * logging.  This option should be followed by two arguments, the first
   1743    * one must be of the form
   1744    *
   1745    *     void * my_logger(void *cls, const char *uri, struct MHD_Connection *con)
   1746    *
   1747    * where the return value will be passed as
   1748    * (`* req_cls`) in calls to the #MHD_AccessHandlerCallback
   1749    * when this request is processed later; returning a
   1750    * value of NULL has no special significance (however,
   1751    * note that if you return non-NULL, you can no longer
   1752    * rely on the first call to the access handler having
   1753    * `NULL == *req_cls` on entry;)
   1754    * "cls" will be set to the second argument following
   1755    * #MHD_OPTION_URI_LOG_CALLBACK.  Finally, uri will
   1756    * be the 0-terminated URI of the request.
   1757    *
   1758    * Note that during the time of this call, most of the connection's
   1759    * state is not initialized (as we have not yet parsed the headers).
   1760    * However, information about the connecting client (IP, socket)
   1761    * is available.
   1762    *
   1763    * The specified function is called only once per request, therefore some
   1764    * programmers may use it to instantiate their own request objects, freeing
   1765    * them in the notifier #MHD_OPTION_NOTIFY_COMPLETED.
   1766    */
   1767   MHD_OPTION_URI_LOG_CALLBACK = 7,
   1768 
   1769   /**
   1770    * Memory pointer for the private key (key.pem) to be used by the
   1771    * HTTPS daemon.  This option should be followed by a
   1772    * `const char *` argument.
   1773    * This should be used in conjunction with #MHD_OPTION_HTTPS_MEM_CERT.
   1774    */
   1775   MHD_OPTION_HTTPS_MEM_KEY = 8,
   1776 
   1777   /**
   1778    * Memory pointer for the certificate (cert.pem) to be used by the
   1779    * HTTPS daemon.  This option should be followed by a
   1780    * `const char *` argument.
   1781    * This should be used in conjunction with #MHD_OPTION_HTTPS_MEM_KEY.
   1782    */
   1783   MHD_OPTION_HTTPS_MEM_CERT = 9,
   1784 
   1785   /**
   1786    * Daemon credentials type.
   1787    * Followed by an argument of type
   1788    * `gnutls_credentials_type_t`.
   1789    */
   1790   MHD_OPTION_HTTPS_CRED_TYPE = 10,
   1791 
   1792   /**
   1793    * Memory pointer to a `const char *` specifying the GnuTLS priorities string.
   1794    * If this options is not specified, then MHD will try the following strings:
   1795    * * "@LIBMICROHTTPD" (application-specific system-wide configuration)
   1796    * * "@SYSTEM"        (system-wide configuration)
   1797    * * default GnuTLS priorities string
   1798    * * "NORMAL"
   1799    * The first configuration accepted by GnuTLS will be used.
   1800    * For more details see GnuTLS documentation for "Application-specific
   1801    * priority strings".
   1802    */
   1803   MHD_OPTION_HTTPS_PRIORITIES = 11,
   1804 
   1805   /**
   1806    * Pass a listen socket for MHD to use (systemd-style).  If this
   1807    * option is used, MHD will not open its own listen socket(s). The
   1808    * argument passed must be of type `MHD_socket` and refer to an
   1809    * existing socket that has been bound to a port and is listening.
   1810    * If followed by MHD_INVALID_SOCKET value, MHD ignores this option
   1811    * and creates socket by itself.
   1812    */
   1813   MHD_OPTION_LISTEN_SOCKET = 12,
   1814 
   1815   /**
   1816    * Use the given function for logging error messages.  This option
   1817    * must be followed by two arguments; the first must be a pointer to
   1818    * a function of type #MHD_LogCallback and the second a pointer
   1819    * `void *` which will be passed as the first argument to the log
   1820    * callback.
   1821    * Should be specified as the first option, otherwise some messages
   1822    * may be printed by standard MHD logger during daemon startup.
   1823    *
   1824    * Note that MHD will not generate any log messages
   1825    * if it was compiled without the "--enable-messages"
   1826    * flag being set.
   1827    */
   1828   MHD_OPTION_EXTERNAL_LOGGER = 13,
   1829 
   1830   /**
   1831    * Number (`unsigned int`) of threads in thread pool. Enable
   1832    * thread pooling by setting this value to to something
   1833    * greater than 1.
   1834    * Can be used only for daemons started with #MHD_USE_INTERNAL_POLLING_THREAD.
   1835    * Ignored if followed by zero value.
   1836    */
   1837   MHD_OPTION_THREAD_POOL_SIZE = 14,
   1838 
   1839   /**
   1840    * Additional options given in an array of `struct MHD_OptionItem`.
   1841    * The array must be terminated with an entry `{MHD_OPTION_END, 0, NULL}`.
   1842    * An example for code using #MHD_OPTION_ARRAY is:
   1843    *
   1844    *     struct MHD_OptionItem ops[] = {
   1845    *       { MHD_OPTION_CONNECTION_LIMIT, 100, NULL },
   1846    *       { MHD_OPTION_CONNECTION_TIMEOUT, 10, NULL },
   1847    *       { MHD_OPTION_END, 0, NULL }
   1848    *     };
   1849    *     d = MHD_start_daemon (0, 8080, NULL, NULL, dh, NULL,
   1850    *                           MHD_OPTION_ARRAY, ops,
   1851    *                           MHD_OPTION_END);
   1852    *
   1853    * For options that expect a single pointer argument, the
   1854    * 'value' member of the `struct MHD_OptionItem` is ignored.
   1855    * For options that expect two pointer arguments, the first
   1856    * argument must be cast to `intptr_t`.
   1857    */
   1858   MHD_OPTION_ARRAY = 15,
   1859 
   1860   /**
   1861    * Specify a function that should be called for unescaping escape
   1862    * sequences in URIs and URI arguments.  Note that this function
   1863    * will NOT be used by the `struct MHD_PostProcessor`.  If this
   1864    * option is not specified, the default method will be used which
   1865    * decodes escape sequences of the form "%HH".  This option should
   1866    * be followed by two arguments, the first one must be of the form
   1867    *
   1868    *     size_t my_unescaper(void *cls,
   1869    *                         struct MHD_Connection *c,
   1870    *                         char *s)
   1871    *
   1872    * where the return value must be the length of the value left in
   1873    * "s" (without the 0-terminator) and "s" should be updated.  Note
   1874    * that the unescape function must not lengthen "s" (the result must
   1875    * be shorter than the input and must still be 0-terminated).
   1876    * However, it may also include binary zeros before the
   1877    * 0-termination.  "cls" will be set to the second argument
   1878    * following #MHD_OPTION_UNESCAPE_CALLBACK.
   1879    */
   1880   MHD_OPTION_UNESCAPE_CALLBACK = 16,
   1881 
   1882   /**
   1883    * Memory pointer for the random values to be used by the Digest
   1884    * Auth module. This option should be followed by two arguments.
   1885    * First an integer of type `size_t` which specifies the size
   1886    * of the buffer pointed to by the second argument in bytes.
   1887    * The recommended size is between 8 and 32. If size is four or less
   1888    * then security could be lowered. Sizes more then 32 (or, probably
   1889    * more than 16 - debatable) will not increase security.
   1890    * Note that the application must ensure that the buffer of the
   1891    * second argument remains allocated and unmodified while the
   1892    * daemon is running.
   1893    * @sa #MHD_OPTION_DIGEST_AUTH_RANDOM_COPY
   1894    */
   1895   MHD_OPTION_DIGEST_AUTH_RANDOM = 17,
   1896 
   1897   /**
   1898    * Size of the internal array holding the map of the nonce and
   1899    * the nonce counter. This option should be followed by an `unsigned int`
   1900    * argument.
   1901    * The map size is 4 by default, which is enough to communicate with
   1902    * a single client at any given moment of time, but not enough to
   1903    * handle several clients simultaneously.
   1904    * If Digest Auth is not used, this option can be set to zero to minimise
   1905    * memory allocation.
   1906    */
   1907   MHD_OPTION_NONCE_NC_SIZE = 18,
   1908 
   1909   /**
   1910    * Desired size of the stack for threads created by MHD. Followed
   1911    * by an argument of type `size_t`.  Use 0 for system default.
   1912    */
   1913   MHD_OPTION_THREAD_STACK_SIZE = 19,
   1914 
   1915   /**
   1916    * Memory pointer for the certificate (ca.pem) to be used by the
   1917    * HTTPS daemon for client authentication.
   1918    * This option should be followed by a `const char *` argument.
   1919    */
   1920   MHD_OPTION_HTTPS_MEM_TRUST = 20,
   1921 
   1922   /**
   1923    * Increment to use for growing the read buffer (followed by a
   1924    * `size_t`).
   1925    * Must not be higher than 1/4 of #MHD_OPTION_CONNECTION_MEMORY_LIMIT.
   1926    * Since #MHD_VERSION 0x00097710 silently ignored if followed by zero value.
   1927    */
   1928   MHD_OPTION_CONNECTION_MEMORY_INCREMENT = 21,
   1929 
   1930   /**
   1931    * Use a callback to determine which X.509 certificate should be
   1932    * used for a given HTTPS connection.  This option should be
   1933    * followed by a argument of type `gnutls_certificate_retrieve_function2 *`.
   1934    * This option provides an
   1935    * alternative to #MHD_OPTION_HTTPS_MEM_KEY,
   1936    * #MHD_OPTION_HTTPS_MEM_CERT.  You must use this version if
   1937    * multiple domains are to be hosted at the same IP address using
   1938    * TLS's Server Name Indication (SNI) extension.  In this case,
   1939    * the callback is expected to select the correct certificate
   1940    * based on the SNI information provided.  The callback is expected
   1941    * to access the SNI data using `gnutls_server_name_get()`.
   1942    * Using this option requires GnuTLS 3.0 or higher.
   1943    */
   1944   MHD_OPTION_HTTPS_CERT_CALLBACK = 22,
   1945 
   1946   /**
   1947    * When using #MHD_USE_TCP_FASTOPEN, this option changes the default TCP
   1948    * fastopen queue length of 50.  Note that having a larger queue size can
   1949    * cause resource exhaustion attack as the TCP stack has to now allocate
   1950    * resources for the SYN packet along with its DATA.  This option should be
   1951    * followed by an `unsigned int` argument.
   1952    */
   1953   MHD_OPTION_TCP_FASTOPEN_QUEUE_SIZE = 23,
   1954 
   1955   /**
   1956    * Memory pointer for the Diffie-Hellman parameters (dh.pem) to be used by the
   1957    * HTTPS daemon for key exchange.
   1958    * This option must be followed by a `const char *` argument.
   1959    */
   1960   MHD_OPTION_HTTPS_MEM_DHPARAMS = 24,
   1961 
   1962   /**
   1963    * If present and set to true, allow reusing address:port socket
   1964    * (by using SO_REUSEPORT on most platform, or platform-specific ways).
   1965    * If present and set to false, disallow reusing address:port socket
   1966    * (does nothing on most platform, but uses SO_EXCLUSIVEADDRUSE on Windows).
   1967    * This option must be followed by a `unsigned int` argument.
   1968    */
   1969   MHD_OPTION_LISTENING_ADDRESS_REUSE = 25,
   1970 
   1971   /**
   1972    * Memory pointer for a password that decrypts the private key (key.pem)
   1973    * to be used by the HTTPS daemon. This option should be followed by a
   1974    * `const char *` argument.
   1975    * This should be used in conjunction with #MHD_OPTION_HTTPS_MEM_KEY.
   1976    * @sa ::MHD_FEATURE_HTTPS_KEY_PASSWORD
   1977    */
   1978   MHD_OPTION_HTTPS_KEY_PASSWORD = 26,
   1979 
   1980   /**
   1981    * Register a function that should be called whenever a connection is
   1982    * started or closed.
   1983    *
   1984    * This option should be followed by TWO pointers.  First a pointer
   1985    * to a function of type #MHD_NotifyConnectionCallback and second a
   1986    * pointer to a closure to pass to the request completed callback.
   1987    * The second pointer may be NULL.
   1988    */
   1989   MHD_OPTION_NOTIFY_CONNECTION = 27,
   1990 
   1991   /**
   1992    * Allow to change maximum length of the queue of pending connections on
   1993    * listen socket. If not present than default platform-specific SOMAXCONN
   1994    * value is used. This option should be followed by an `unsigned int`
   1995    * argument.
   1996    */
   1997   MHD_OPTION_LISTEN_BACKLOG_SIZE = 28,
   1998 
   1999   /**
   2000    * If set to 1 - be strict about the protocol.  Use -1 to be
   2001    * as tolerant as possible.
   2002    *
   2003    * The more flexible option #MHD_OPTION_CLIENT_DISCIPLINE_LVL is recommended
   2004    * instead of this option.
   2005    *
   2006    * The values mapping table:
   2007    * #MHD_OPTION_STRICT_FOR_CLIENT | #MHD_OPTION_CLIENT_DISCIPLINE_LVL
   2008    * -----------------------------:|:---------------------------------
   2009    * 1                             | 1
   2010    * 0                             | 0
   2011    * -1                            | -3
   2012    *
   2013    * This option should be followed by an `int` argument.
   2014    * @sa #MHD_OPTION_CLIENT_DISCIPLINE_LVL
   2015    */
   2016   MHD_OPTION_STRICT_FOR_CLIENT = 29,
   2017 
   2018   /**
   2019    * This should be a pointer to callback of type
   2020    * gnutls_psk_server_credentials_function that will be given to
   2021    * gnutls_psk_set_server_credentials_function. It is used to
   2022    * retrieve the shared key for a given username.
   2023    */
   2024   MHD_OPTION_GNUTLS_PSK_CRED_HANDLER = 30,
   2025 
   2026   /**
   2027    * Use a callback to determine which X.509 certificate should be
   2028    * used for a given HTTPS connection.  This option should be
   2029    * followed by a argument of type `gnutls_certificate_retrieve_function3 *`.
   2030    * This option provides an
   2031    * alternative/extension to #MHD_OPTION_HTTPS_CERT_CALLBACK.
   2032    * You must use this version if you want to use OCSP stapling.
   2033    * Using this option requires GnuTLS 3.6.3 or higher.
   2034    */
   2035   MHD_OPTION_HTTPS_CERT_CALLBACK2 = 31,
   2036 
   2037   /**
   2038    * Allows the application to disable certain sanity precautions
   2039    * in MHD. With these, the client can break the HTTP protocol,
   2040    * so this should never be used in production. The options are,
   2041    * however, useful for testing HTTP clients against "broken"
   2042    * server implementations.
   2043    * This argument must be followed by an "unsigned int", corresponding
   2044    * to an `enum MHD_DisableSanityCheck`.
   2045    */
   2046   MHD_OPTION_SERVER_INSANITY = 32,
   2047 
   2048   /**
   2049    * If followed by value '1' informs MHD that SIGPIPE is suppressed or
   2050    * handled by application. Allows MHD to use network functions that could
   2051    * generate SIGPIPE, like `sendfile()`.
   2052    * Valid only for daemons without #MHD_USE_INTERNAL_POLLING_THREAD as
   2053    * MHD automatically suppresses SIGPIPE for threads started by MHD.
   2054    * This option should be followed by an `int` argument.
   2055    * @note Available since #MHD_VERSION 0x00097205
   2056    */
   2057   MHD_OPTION_SIGPIPE_HANDLED_BY_APP = 33,
   2058 
   2059   /**
   2060    * If followed by 'int' with value '1' disables usage of ALPN for TLS
   2061    * connections even if supported by TLS library.
   2062    * Valid only for daemons with #MHD_USE_TLS.
   2063    * This option should be followed by an `int` argument.
   2064    * @note Available since #MHD_VERSION 0x00097207
   2065    */
   2066   MHD_OPTION_TLS_NO_ALPN = 34,
   2067 
   2068   /**
   2069    * Memory pointer for the random values to be used by the Digest
   2070    * Auth module. This option should be followed by two arguments.
   2071    * First an integer of type `size_t` which specifies the size
   2072    * of the buffer pointed to by the second argument in bytes.
   2073    * The recommended size is between 8 and 32. If size is four or less
   2074    * then security could be lowered. Sizes more then 32 (or, probably
   2075    * more than 16 - debatable) will not increase security.
   2076    * An internal copy of the buffer will be made, the data do not
   2077    * need to be static.
   2078    * @sa #MHD_OPTION_DIGEST_AUTH_RANDOM
   2079    * @note Available since #MHD_VERSION 0x00097701
   2080    */
   2081   MHD_OPTION_DIGEST_AUTH_RANDOM_COPY = 35,
   2082 
   2083   /**
   2084    * Allow to controls the scope of validity of MHD-generated nonces.
   2085    * This regulates how "nonces" are generated and how "nonces" are checked by
   2086    * #MHD_digest_auth_check3() and similar functions.
   2087    * This option should be followed by an 'unsigned int` argument with value
   2088    * formed as bitwise OR combination of #MHD_DAuthBindNonce values.
   2089    * When not specified, default value #MHD_DAUTH_BIND_NONCE_NONE is used.
   2090    * @note Available since #MHD_VERSION 0x00097701
   2091    */
   2092   MHD_OPTION_DIGEST_AUTH_NONCE_BIND_TYPE = 36,
   2093 
   2094   /**
   2095    * Memory pointer to a `const char *` specifying the GnuTLS priorities to be
   2096    * appended to default priorities.
   2097    * This allow some specific options to be enabled/disabled, while leaving
   2098    * the rest of the settings to their defaults.
   2099    * The string does not have to start with a colon ':' character.
   2100    * See #MHD_OPTION_HTTPS_PRIORITIES description for details of automatic
   2101    * default priorities.
   2102    * @note Available since #MHD_VERSION 0x00097701
   2103    */
   2104   MHD_OPTION_HTTPS_PRIORITIES_APPEND = 37,
   2105 
   2106   /**
   2107    * Sets specified client discipline level (i.e. HTTP protocol parsing
   2108    * strictness level).
   2109    *
   2110    * The following basic values are supported:
   2111    *  0 - default MHD level, a balance between extra security and broader
   2112    *      compatibility, as allowed by RFCs for HTTP servers;
   2113    *  1 - more strict protocol interpretation, within the limits set by
   2114    *      RFCs for HTTP servers;
   2115    * -1 - more lenient protocol interpretation, within the limits set by
   2116    *      RFCs for HTTP servers.
   2117    * The following extended values could be used as well:
   2118    *  2 - stricter protocol interpretation, even stricter then allowed
   2119    *      by RFCs for HTTP servers, however it should be absolutely compatible
   2120    *      with clients following at least RFCs' "MUST" type of requirements
   2121    *      for HTTP clients;
   2122    *  3 - strictest protocol interpretation, even stricter then allowed
   2123    *      by RFCs for HTTP servers, however it should be absolutely compatible
   2124    *      with clients following RFCs' "SHOULD" and "MUST" types of requirements
   2125    *      for HTTP clients;
   2126    * -2 - more relaxed protocol interpretation, violating RFCs' "SHOULD" type
   2127    *      of requirements for HTTP servers;
   2128    * -3 - the most flexible protocol interpretation, beyond RFCs' "MUST" type of
   2129    *      requirements for HTTP server.
   2130    * Values higher than "3" or lower than "-3" are interpreted as "3" or "-3"
   2131    * respectively.
   2132    *
   2133    * Higher values are more secure, lower values are more compatible with
   2134    * various HTTP clients.
   2135    *
   2136    * The default value ("0") could be used in most cases.
   2137    * Value "1" is suitable for highly loaded public servers.
   2138    * Values "2" and "3" are generally recommended only for testing of HTTP
   2139    * clients against MHD.
   2140    * Value "2" may be used for security-centric application, however it is
   2141    * slight violation of RFCs' requirements.
   2142    * Negative values are not recommended for public servers.
   2143    * Values "-1" and "-2" could be used for servers in isolated environment.
   2144    * Value "-3" is not recommended unless it is absolutely necessary to
   2145    * communicate with some client(s) with badly broken HTTP implementation.
   2146    *
   2147    * This option should be followed by an `int` argument.
   2148    * @note Available since #MHD_VERSION 0x00097701
   2149    */
   2150   MHD_OPTION_CLIENT_DISCIPLINE_LVL = 38,
   2151 
   2152   /**
   2153    * Specifies value of FD_SETSIZE used by application.  Only For external
   2154    * polling modes (without MHD internal threads).
   2155    * Some platforms (FreeBSD, Solaris, W32 etc.) allow overriding of FD_SETSIZE
   2156    * value.  When polling by select() is used, MHD rejects sockets with numbers
   2157    * equal or higher than FD_SETSIZE.  If this option is used, MHD treats this
   2158    * value as a limitation for socket number instead of FD_SETSIZE value which
   2159    * was used for building MHD.
   2160    * When external polling is used with #MHD_get_fdset2() (or #MHD_get_fdset()
   2161    * macro) and #MHD_run_from_select() interfaces, it is recommended to always
   2162    * use this option.
   2163    * It is safe to use this option on platforms with fixed FD_SETSIZE (like
   2164    * GNU/Linux) if system value of FD_SETSIZE is used as the argument.
   2165    * Can be used only for daemons without #MHD_USE_INTERNAL_POLLING_THREAD, i.e.
   2166    * only when external sockets polling is used.
   2167    * On W32 it is silently ignored, as W32 does not limit the socket number in
   2168    * fd_sets.
   2169    * This option should be followed by a positive 'int' argument.
   2170    * @note Available since #MHD_VERSION 0x00097705
   2171    */
   2172   MHD_OPTION_APP_FD_SETSIZE = 39,
   2173 
   2174   /**
   2175    * Bind daemon to the supplied 'struct sockaddr'.  This option should
   2176    * be followed by two parameters: 'socklen_t' the size of memory at the next
   2177    * pointer and the pointer 'const struct sockaddr *'.
   2178    * Note: the order of the arguments is not the same as for system bind() and
   2179    * other network functions.
   2180    * If #MHD_USE_IPv6 is specified, the 'struct sockaddr*' should
   2181    * point to a 'struct sockaddr_in6'.
   2182    * The socket domain (protocol family) is detected from provided
   2183    * 'struct sockaddr'. IP, IPv6 and UNIX sockets are supported (if supported
   2184    * by the platform). Other types may work occasionally.
   2185    * Silently ignored if followed by zero size and NULL pointer.
   2186    * @note Available since #MHD_VERSION 0x00097706
   2187    */
   2188   MHD_OPTION_SOCK_ADDR_LEN = 40
   2189   ,
   2190   /**
   2191    * Default nonce timeout value used for Digest Auth.
   2192    * This option should be followed by an 'unsigned int' argument.
   2193    * Silently ignored if followed by zero value.
   2194    * @see #MHD_digest_auth_check3(), MHD_digest_auth_check_digest3()
   2195    * @note Available since #MHD_VERSION 0x00097709
   2196    */
   2197   MHD_OPTION_DIGEST_AUTH_DEFAULT_NONCE_TIMEOUT = 41
   2198   ,
   2199   /**
   2200    * Default maximum nc (nonce count) value used for Digest Auth.
   2201    * This option should be followed by an 'uint32_t' argument.
   2202    * Silently ignored if followed by zero value.
   2203    * @see #MHD_digest_auth_check3(), MHD_digest_auth_check_digest3()
   2204    * @note Available since #MHD_VERSION 0x00097709
   2205    */
   2206   MHD_OPTION_DIGEST_AUTH_DEFAULT_MAX_NC = 42
   2207   ,
   2208   /**
   2209    * Default maximum nc (nonce count) value used for Digest Auth.
   2210    * This option must be followed by an 'int' argument.
   2211    * If followed by '0' (default) then:
   2212    * + requests are rejected if request URI has binary zero (the result
   2213    *   of %00 decoding) in the path part of the URI.
   2214    * If followed by '1' then:
   2215    * + binary zero is allowed in request URI path;
   2216    * + #MHD_AccessHandlerCallback called with NULL in @a url parameter when
   2217    *   request URI path has binary zero, the full @a url is available only
   2218    *   via #MHD_get_connection_URI_path_n()
   2219    * If followed by '2' (unsafe!) then:
   2220    * + binary zero is allowed in request URI path;
   2221    * + #MHD_AccessHandlerCallback called with truncated (unsafe!) @a url
   2222    *   parameter when request URI path has binary zero.
   2223    * @see #MHD_get_connection_URI_path_n()
   2224    * @note Available since #MHD_VERSION 0x01000201
   2225    */
   2226   MHD_OPTION_ALLOW_BIN_ZERO_IN_URI_PATH = 43
   2227 
   2228 } _MHD_FIXED_ENUM;
   2229 
   2230 
   2231 /**
   2232  * Bitfield for the #MHD_OPTION_SERVER_INSANITY specifying
   2233  * which santiy checks should be disabled.
   2234  */
   2235 enum MHD_DisableSanityCheck
   2236 {
   2237   /**
   2238    * All sanity checks are enabled.
   2239    */
   2240   MHD_DSC_SANE = 0
   2241 
   2242 } _MHD_FIXED_FLAGS_ENUM;
   2243 
   2244 
   2245 /**
   2246  * Entry in an #MHD_OPTION_ARRAY.
   2247  */
   2248 struct MHD_OptionItem
   2249 {
   2250   /**
   2251    * Which option is being given.  Use #MHD_OPTION_END
   2252    * to terminate the array.
   2253    */
   2254   enum MHD_OPTION option;
   2255 
   2256   /**
   2257    * Option value (for integer arguments, and for options requiring
   2258    * two pointer arguments); should be 0 for options that take no
   2259    * arguments or only a single pointer argument.
   2260    */
   2261   intptr_t value;
   2262 
   2263   /**
   2264    * Pointer option value (use NULL for options taking no arguments
   2265    * or only an integer option).
   2266    */
   2267   void *ptr_value;
   2268 
   2269 };
   2270 
   2271 
   2272 /**
   2273  * The `enum MHD_ValueKind` specifies the source of
   2274  * the key-value pairs in the HTTP protocol.
   2275  */
   2276 enum MHD_ValueKind
   2277 {
   2278 
   2279   /**
   2280    * Response header
   2281    * @deprecated
   2282    */
   2283   MHD_RESPONSE_HEADER_KIND = 0,
   2284 #define MHD_RESPONSE_HEADER_KIND \
   2285         _MHD_DEPR_IN_MACRO ( \
   2286           "Value MHD_RESPONSE_HEADER_KIND is deprecated and not used") \
   2287         MHD_RESPONSE_HEADER_KIND
   2288 
   2289   /**
   2290    * HTTP header (request/response).
   2291    */
   2292   MHD_HEADER_KIND = 1,
   2293 
   2294   /**
   2295    * Cookies.  Note that the original HTTP header containing
   2296    * the cookie(s) will still be available and intact.
   2297    */
   2298   MHD_COOKIE_KIND = 2,
   2299 
   2300   /**
   2301    * POST data.  This is available only if a content encoding
   2302    * supported by MHD is used (currently only URL encoding),
   2303    * and only if the posted content fits within the available
   2304    * memory pool.  Note that in that case, the upload data
   2305    * given to the #MHD_AccessHandlerCallback will be
   2306    * empty (since it has already been processed).
   2307    */
   2308   MHD_POSTDATA_KIND = 4,
   2309 
   2310   /**
   2311    * GET (URI) arguments.
   2312    */
   2313   MHD_GET_ARGUMENT_KIND = 8,
   2314 
   2315   /**
   2316    * HTTP footer (only for HTTP 1.1 chunked encodings).
   2317    */
   2318   MHD_FOOTER_KIND = 16
   2319 } _MHD_FIXED_ENUM;
   2320 
   2321 
   2322 /**
   2323  * The `enum MHD_RequestTerminationCode` specifies reasons
   2324  * why a request has been terminated (or completed).
   2325  * @ingroup request
   2326  */
   2327 enum MHD_RequestTerminationCode
   2328 {
   2329 
   2330   /**
   2331    * We finished sending the response.
   2332    * @ingroup request
   2333    */
   2334   MHD_REQUEST_TERMINATED_COMPLETED_OK = 0,
   2335 
   2336   /**
   2337    * Error handling the connection (resources
   2338    * exhausted, application error accepting request,
   2339    * decrypt error (for HTTPS), connection died when
   2340    * sending the response etc.)
   2341    * @ingroup request
   2342    */
   2343   MHD_REQUEST_TERMINATED_WITH_ERROR = 1,
   2344 
   2345   /**
   2346    * No activity on the connection for the number
   2347    * of seconds specified using
   2348    * #MHD_OPTION_CONNECTION_TIMEOUT.
   2349    * @ingroup request
   2350    */
   2351   MHD_REQUEST_TERMINATED_TIMEOUT_REACHED = 2,
   2352 
   2353   /**
   2354    * We had to close the session since MHD was being
   2355    * shut down.
   2356    * @ingroup request
   2357    */
   2358   MHD_REQUEST_TERMINATED_DAEMON_SHUTDOWN = 3,
   2359 
   2360   /**
   2361    * We tried to read additional data, but the connection became broken or
   2362    * the other side hard closed the connection.
   2363    * This error is similar to #MHD_REQUEST_TERMINATED_WITH_ERROR, but
   2364    * specific to the case where the connection died before request completely
   2365    * received.
   2366    * @ingroup request
   2367    */
   2368   MHD_REQUEST_TERMINATED_READ_ERROR = 4,
   2369 
   2370   /**
   2371    * The client terminated the connection by closing the socket
   2372    * for writing (TCP half-closed) while still sending request.
   2373    * @ingroup request
   2374    */
   2375   MHD_REQUEST_TERMINATED_CLIENT_ABORT = 5
   2376 
   2377 } _MHD_FIXED_ENUM;
   2378 
   2379 
   2380 /**
   2381  * The `enum MHD_ConnectionNotificationCode` specifies types
   2382  * of connection notifications.
   2383  * @ingroup request
   2384  */
   2385 enum MHD_ConnectionNotificationCode
   2386 {
   2387 
   2388   /**
   2389    * A new connection has been started.
   2390    * @ingroup request
   2391    */
   2392   MHD_CONNECTION_NOTIFY_STARTED = 0,
   2393 
   2394   /**
   2395    * A connection is closed.
   2396    * @ingroup request
   2397    */
   2398   MHD_CONNECTION_NOTIFY_CLOSED = 1
   2399 
   2400 } _MHD_FIXED_ENUM;
   2401 
   2402 
   2403 /**
   2404  * Information about a connection.
   2405  */
   2406 union MHD_ConnectionInfo
   2407 {
   2408 
   2409   /**
   2410    * Cipher algorithm used, of type "enum gnutls_cipher_algorithm".
   2411    */
   2412   int /* enum gnutls_cipher_algorithm */ cipher_algorithm;
   2413 
   2414   /**
   2415    * Protocol used, of type "enum gnutls_protocol".
   2416    */
   2417   int /* enum gnutls_protocol */ protocol;
   2418 
   2419   /**
   2420    * The suspended status of a connection.
   2421    */
   2422   int /* MHD_YES or MHD_NO */ suspended;
   2423 
   2424   /**
   2425    * Amount of second that connection could spend in idle state
   2426    * before automatically disconnected.
   2427    * Zero for no timeout (unlimited idle time).
   2428    */
   2429   unsigned int connection_timeout;
   2430 
   2431   /**
   2432    * HTTP status queued with the response, for #MHD_CONNECTION_INFO_HTTP_STATUS.
   2433    */
   2434   unsigned int http_status;
   2435 
   2436   /**
   2437    * Connect socket
   2438    */
   2439   MHD_socket connect_fd;
   2440 
   2441   /**
   2442    * Size of the client's HTTP header.
   2443    * It includes the request line, all request headers, the header section
   2444    * terminating empty line, with all CRLF (or LF) characters.
   2445    */
   2446   size_t header_size;
   2447 
   2448   /**
   2449    * GNUtls session handle, of type "gnutls_session_t".
   2450    */
   2451   void * /* gnutls_session_t */ tls_session;
   2452 
   2453   /**
   2454    * GNUtls client certificate handle, of type "gnutls_x509_crt_t".
   2455    */
   2456   void * /* gnutls_x509_crt_t */ client_cert;
   2457 
   2458   /**
   2459    * Address information for the client.
   2460    */
   2461   struct sockaddr *client_addr;
   2462 
   2463   /**
   2464    * Which daemon manages this connection (useful in case there are many
   2465    * daemons running).
   2466    */
   2467   struct MHD_Daemon *daemon;
   2468 
   2469   /**
   2470    * Socket-specific client context.  Points to the same address as
   2471    * the "socket_context" of the #MHD_NotifyConnectionCallback.
   2472    */
   2473   void *socket_context;
   2474 };
   2475 
   2476 
   2477 /**
   2478  * I/O vector type. Provided for use with #MHD_create_response_from_iovec().
   2479  * @note Available since #MHD_VERSION 0x00097204
   2480  */
   2481 struct MHD_IoVec
   2482 {
   2483   /**
   2484    * The pointer to the memory region for I/O.
   2485    */
   2486   const void *iov_base;
   2487 
   2488   /**
   2489    * The size in bytes of the memory region for I/O.
   2490    */
   2491   size_t iov_len;
   2492 };
   2493 
   2494 
   2495 /**
   2496  * Values of this enum are used to specify what
   2497  * information about a connection is desired.
   2498  * @ingroup request
   2499  */
   2500 enum MHD_ConnectionInfoType
   2501 {
   2502   /**
   2503    * What cipher algorithm is being used.
   2504    * Takes no extra arguments.
   2505    * @ingroup request
   2506    */
   2507   MHD_CONNECTION_INFO_CIPHER_ALGO,
   2508 
   2509   /**
   2510    *
   2511    * Takes no extra arguments.
   2512    * @ingroup request
   2513    */
   2514   MHD_CONNECTION_INFO_PROTOCOL,
   2515 
   2516   /**
   2517    * Obtain IP address of the client.  Takes no extra arguments.
   2518    * Returns essentially a `struct sockaddr **` (since the API returns
   2519    * a `union MHD_ConnectionInfo *` and that union contains a `struct
   2520    * sockaddr *`).
   2521    * @ingroup request
   2522    */
   2523   MHD_CONNECTION_INFO_CLIENT_ADDRESS,
   2524 
   2525   /**
   2526    * Get the gnuTLS session handle.
   2527    * @ingroup request
   2528    */
   2529   MHD_CONNECTION_INFO_GNUTLS_SESSION,
   2530 
   2531   /**
   2532    * Get the gnuTLS client certificate handle.  Dysfunctional (never
   2533    * implemented, deprecated).  Use #MHD_CONNECTION_INFO_GNUTLS_SESSION
   2534    * to get the `gnutls_session_t` and then call
   2535    * gnutls_certificate_get_peers().
   2536    */
   2537   MHD_CONNECTION_INFO_GNUTLS_CLIENT_CERT,
   2538 
   2539   /**
   2540    * Get the `struct MHD_Daemon *` responsible for managing this connection.
   2541    * @ingroup request
   2542    */
   2543   MHD_CONNECTION_INFO_DAEMON,
   2544 
   2545   /**
   2546    * Request the file descriptor for the connection socket.
   2547    * MHD sockets are always in non-blocking mode.
   2548    * No extra arguments should be passed.
   2549    * @ingroup request
   2550    */
   2551   MHD_CONNECTION_INFO_CONNECTION_FD,
   2552 
   2553   /**
   2554    * Returns the client-specific pointer to a `void *` that was (possibly)
   2555    * set during a #MHD_NotifyConnectionCallback when the socket was
   2556    * first accepted.
   2557    * Note that this is NOT the same as the "req_cls" argument of
   2558    * the #MHD_AccessHandlerCallback. The "req_cls" is fresh for each
   2559    * HTTP request, while the "socket_context" is fresh for each socket.
   2560    */
   2561   MHD_CONNECTION_INFO_SOCKET_CONTEXT,
   2562 
   2563   /**
   2564    * Check whether the connection is suspended.
   2565    * @ingroup request
   2566    */
   2567   MHD_CONNECTION_INFO_CONNECTION_SUSPENDED,
   2568 
   2569   /**
   2570    * Get connection timeout
   2571    * @ingroup request
   2572    */
   2573   MHD_CONNECTION_INFO_CONNECTION_TIMEOUT,
   2574 
   2575   /**
   2576    * Return length of the client's HTTP request header.
   2577    * @ingroup request
   2578    */
   2579   MHD_CONNECTION_INFO_REQUEST_HEADER_SIZE,
   2580 
   2581   /**
   2582    * Return HTTP status queued with the response. NULL
   2583    * if no HTTP response has been queued yet.
   2584    */
   2585   MHD_CONNECTION_INFO_HTTP_STATUS
   2586 
   2587 } _MHD_FIXED_ENUM;
   2588 
   2589 
   2590 /**
   2591  * Values of this enum are used to specify what
   2592  * information about a daemon is desired.
   2593  */
   2594 enum MHD_DaemonInfoType
   2595 {
   2596   /**
   2597    * No longer supported (will return NULL).
   2598    */
   2599   MHD_DAEMON_INFO_KEY_SIZE,
   2600 
   2601   /**
   2602    * No longer supported (will return NULL).
   2603    */
   2604   MHD_DAEMON_INFO_MAC_KEY_SIZE,
   2605 
   2606   /**
   2607    * Request the file descriptor for the listening socket.
   2608    * No extra arguments should be passed.
   2609    */
   2610   MHD_DAEMON_INFO_LISTEN_FD,
   2611 
   2612   /**
   2613    * Request the file descriptor for the "external" sockets polling
   2614    * when 'epoll' mode is used.
   2615    * No extra arguments should be passed.
   2616    *
   2617    * Waiting on epoll FD must not block longer than value
   2618    * returned by #MHD_get_timeout() otherwise connections
   2619    * will "hung" with unprocessed data in network buffers
   2620    * and timed-out connections will not be closed.
   2621    *
   2622    * @sa #MHD_get_timeout(), #MHD_run()
   2623    */
   2624   MHD_DAEMON_INFO_EPOLL_FD_LINUX_ONLY,
   2625   MHD_DAEMON_INFO_EPOLL_FD = MHD_DAEMON_INFO_EPOLL_FD_LINUX_ONLY,
   2626 
   2627   /**
   2628    * Request the number of current connections handled by the daemon.
   2629    * No extra arguments should be passed.
   2630    * Note: when using MHD in "external" polling mode, this type of request
   2631    * could be used only when #MHD_run()/#MHD_run_from_select is not
   2632    * working in other thread at the same time.
   2633    */
   2634   MHD_DAEMON_INFO_CURRENT_CONNECTIONS,
   2635 
   2636   /**
   2637    * Request the daemon flags.
   2638    * No extra arguments should be passed.
   2639    * Note: flags may differ from original 'flags' specified for
   2640    * daemon, especially if #MHD_USE_AUTO was set.
   2641    */
   2642   MHD_DAEMON_INFO_FLAGS,
   2643 
   2644   /**
   2645    * Request the port number of daemon's listen socket.
   2646    * No extra arguments should be passed.
   2647    * Note: if port '0' was specified for #MHD_start_daemon(), returned
   2648    * value will be real port number.
   2649    */
   2650   MHD_DAEMON_INFO_BIND_PORT
   2651 } _MHD_FIXED_ENUM;
   2652 
   2653 
   2654 /**
   2655  * Callback for serious error condition. The default action is to print
   2656  * an error message and `abort()`.
   2657  *
   2658  * @param cls user specified value
   2659  * @param file where the error occurred, may be NULL if MHD was built without
   2660  *             messages support
   2661  * @param line where the error occurred
   2662  * @param reason error detail, may be NULL
   2663  * @ingroup logging
   2664  */
   2665 typedef void
   2666 (*MHD_PanicCallback) (void *cls,
   2667                       const char *file,
   2668                       unsigned int line,
   2669                       const char *reason);
   2670 
   2671 /**
   2672  * Allow or deny a client to connect.
   2673  *
   2674  * @param cls closure
   2675  * @param addr address information from the client
   2676  * @param addrlen length of @a addr
   2677  * @return #MHD_YES if connection is allowed, #MHD_NO if not
   2678  */
   2679 typedef enum MHD_Result
   2680 (*MHD_AcceptPolicyCallback)(void *cls,
   2681                             const struct sockaddr *addr,
   2682                             socklen_t addrlen);
   2683 
   2684 
   2685 /**
   2686  * A client has requested the given @a url using the given @a method
   2687  * (#MHD_HTTP_METHOD_GET, #MHD_HTTP_METHOD_PUT, #MHD_HTTP_METHOD_DELETE,
   2688  * #MHD_HTTP_METHOD_POST, etc).
   2689  *
   2690  * The callback must call MHD function MHD_queue_response() to provide content
   2691  * to give back to the client and return an HTTP status code (i.e.
   2692  * #MHD_HTTP_OK, #MHD_HTTP_NOT_FOUND, etc.). The response can be created
   2693  * in this callback or prepared in advance.
   2694  * Alternatively, callback may call MHD_suspend_connection() to temporarily
   2695  * suspend data processing for this connection.
   2696  *
   2697  * As soon as response is provided this callback will not be called anymore
   2698  * for the current request.
   2699  *
   2700  * For each HTTP request this callback is called several times:
   2701  * * after request headers are fully received and decoded,
   2702  * * for each received part of request body (optional, if request has body),
   2703  * * when request is fully received.
   2704  *
   2705  * If response is provided before request is fully received, the rest
   2706  * of the request is discarded and connection is automatically closed
   2707  * after sending response.
   2708  *
   2709  * If the request is fully received, but response hasn't been provided and
   2710  * connection is not suspended, the callback can be called again immediately.
   2711  *
   2712  * The response cannot be queued when this callback is called to process
   2713  * the client upload data (when @a upload_data is not NULL).
   2714  *
   2715  * @param cls argument given together with the function
   2716  *        pointer when the handler was registered with MHD
   2717  * @param connection the connection handle
   2718  * @param url the requested url, can be truncated or can be NULL, depending
   2719  *        on #MHD_OPTION_ALLOW_BIN_ZERO_IN_URI_PATH option,
   2720  *        see #MHD_get_connection_URI_path_n()
   2721  * @param method the HTTP method used (#MHD_HTTP_METHOD_GET,
   2722  *        #MHD_HTTP_METHOD_PUT, etc.)
   2723  * @param version the HTTP version string (i.e.
   2724  *        #MHD_HTTP_VERSION_1_1)
   2725  * @param upload_data the data being uploaded (excluding HEADERS,
   2726  *        for a POST that fits into memory and that is encoded
   2727  *        with a supported encoding, the POST data will NOT be
   2728  *        given in upload_data and is instead available as
   2729  *        part of #MHD_get_connection_values; very large POST
   2730  *        data *will* be made available incrementally in
   2731  *        @a upload_data)
   2732  * @param[in,out] upload_data_size set initially to the size of the
   2733  *        @a upload_data provided; the method must update this
   2734  *        value to the number of bytes NOT processed;
   2735  * @param[in,out] req_cls pointer that the callback can set to some
   2736  *        address and that will be preserved by MHD for future
   2737  *        calls for this request; since the access handler may
   2738  *        be called many times (i.e., for a PUT/POST operation
   2739  *        with plenty of upload data) this allows the application
   2740  *        to easily associate some request-specific state.
   2741  *        If necessary, this state can be cleaned up in the
   2742  *        global #MHD_RequestCompletedCallback (which
   2743  *        can be set with the #MHD_OPTION_NOTIFY_COMPLETED).
   2744  *        Initially, `*req_cls` will be NULL.
   2745  * @return #MHD_YES if the connection was handled successfully,
   2746  *         #MHD_NO if the socket must be closed due to a serious
   2747  *         error while handling the request
   2748  *
   2749  * @sa #MHD_queue_response(), #MHD_get_connection_URI_path_n()
   2750  */
   2751 typedef enum MHD_Result
   2752 (*MHD_AccessHandlerCallback)(void *cls,
   2753                              struct MHD_Connection *connection,
   2754                              const char *url,
   2755                              const char *method,
   2756                              const char *version,
   2757                              const char *upload_data,
   2758                              size_t *upload_data_size,
   2759                              void **req_cls);
   2760 
   2761 
   2762 /**
   2763  * Signature of the callback used by MHD to notify the
   2764  * application about completed requests.
   2765  *
   2766  * @param cls client-defined closure
   2767  * @param connection connection handle
   2768  * @param req_cls value as set by the last call to
   2769  *        the #MHD_AccessHandlerCallback
   2770  * @param toe reason for request termination
   2771  * @see #MHD_OPTION_NOTIFY_COMPLETED
   2772  * @ingroup request
   2773  */
   2774 typedef void
   2775 (*MHD_RequestCompletedCallback) (void *cls,
   2776                                  struct MHD_Connection *connection,
   2777                                  void **req_cls,
   2778                                  enum MHD_RequestTerminationCode toe);
   2779 
   2780 
   2781 /**
   2782  * Signature of the callback used by MHD to notify the
   2783  * application about started/stopped connections
   2784  *
   2785  * @param cls client-defined closure
   2786  * @param connection connection handle
   2787  * @param socket_context socket-specific pointer where the
   2788  *                       client can associate some state specific
   2789  *                       to the TCP connection; note that this is
   2790  *                       different from the "req_cls" which is per
   2791  *                       HTTP request.  The client can initialize
   2792  *                       during #MHD_CONNECTION_NOTIFY_STARTED and
   2793  *                       cleanup during #MHD_CONNECTION_NOTIFY_CLOSED
   2794  *                       and access in the meantime using
   2795  *                       #MHD_CONNECTION_INFO_SOCKET_CONTEXT.
   2796  * @param toe reason for connection notification
   2797  * @see #MHD_OPTION_NOTIFY_CONNECTION
   2798  * @ingroup request
   2799  */
   2800 typedef void
   2801 (*MHD_NotifyConnectionCallback) (void *cls,
   2802                                  struct MHD_Connection *connection,
   2803                                  void **socket_context,
   2804                                  enum MHD_ConnectionNotificationCode toe);
   2805 
   2806 
   2807 /**
   2808  * Iterator over key-value pairs.  This iterator
   2809  * can be used to iterate over all of the cookies,
   2810  * headers, or POST-data fields of a request, and
   2811  * also to iterate over the headers that have been
   2812  * added to a response.
   2813  *
   2814  * @param cls closure
   2815  * @param kind kind of the header we are looking at
   2816  * @param key key for the value, can be an empty string
   2817  * @param value corresponding value, can be NULL
   2818  * @return #MHD_YES to continue iterating,
   2819  *         #MHD_NO to abort the iteration
   2820  * @ingroup request
   2821  */
   2822 typedef enum MHD_Result
   2823 (*MHD_KeyValueIterator)(void *cls,
   2824                         enum MHD_ValueKind kind,
   2825                         const char *key,
   2826                         const char *value);
   2827 
   2828 
   2829 /**
   2830  * Iterator over key-value pairs with size parameters.
   2831  * This iterator can be used to iterate over all of
   2832  * the cookies, headers, or POST-data fields of a
   2833  * request, and also to iterate over the headers that
   2834  * have been added to a response.
   2835  * @note Available since #MHD_VERSION 0x00096303
   2836  *
   2837  * @param cls closure
   2838  * @param kind kind of the header we are looking at
   2839  * @param key key for the value, can be an empty string
   2840  * @param value corresponding value, can be NULL
   2841  * @param value_size number of bytes in @a value;
   2842  *                   for C-strings, the length excludes the 0-terminator
   2843  * @return #MHD_YES to continue iterating,
   2844  *         #MHD_NO to abort the iteration
   2845  * @ingroup request
   2846  */
   2847 typedef enum MHD_Result
   2848 (*MHD_KeyValueIteratorN)(void *cls,
   2849                          enum MHD_ValueKind kind,
   2850                          const char *key,
   2851                          size_t key_size,
   2852                          const char *value,
   2853                          size_t value_size);
   2854 
   2855 
   2856 /**
   2857  * Callback used by libmicrohttpd in order to obtain content.
   2858  *
   2859  * The callback is to copy at most @a max bytes of content into @a buf.
   2860  * The total number of bytes that has been placed into @a buf should be
   2861  * returned.
   2862  *
   2863  * Note that returning zero will cause libmicrohttpd to try again.
   2864  * Thus, returning zero should only be used in conjunction
   2865  * with MHD_suspend_connection() to avoid busy waiting.
   2866  *
   2867  * @param cls extra argument to the callback
   2868  * @param pos position in the datastream to access;
   2869  *        note that if a `struct MHD_Response` object is re-used,
   2870  *        it is possible for the same content reader to
   2871  *        be queried multiple times for the same data;
   2872  *        however, if a `struct MHD_Response` is not re-used,
   2873  *        libmicrohttpd guarantees that "pos" will be
   2874  *        the sum of all non-negative return values
   2875  *        obtained from the content reader so far.
   2876  * @param buf where to copy the data
   2877  * @param max maximum number of bytes to copy to @a buf (size of @a buf)
   2878  * @return number of bytes written to @a buf;
   2879  *  0 is legal unless MHD is started in "internal" sockets polling mode
   2880  *    (since this would cause busy-waiting); 0 in "external" sockets
   2881  *    polling mode will cause this function to be called again once
   2882  *    any MHD_run*() function is called;
   2883  *  #MHD_CONTENT_READER_END_OF_STREAM (-1) for the regular
   2884  *    end of transmission (with chunked encoding, MHD will then
   2885  *    terminate the chunk and send any HTTP footers that might be
   2886  *    present; without chunked encoding and given an unknown
   2887  *    response size, MHD will simply close the connection; note
   2888  *    that while returning #MHD_CONTENT_READER_END_OF_STREAM is not technically
   2889  *    legal if a response size was specified, MHD accepts this
   2890  *    and treats it just as #MHD_CONTENT_READER_END_WITH_ERROR;
   2891  *  #MHD_CONTENT_READER_END_WITH_ERROR (-2) to indicate a server
   2892  *    error generating the response; this will cause MHD to simply
   2893  *    close the connection immediately.  If a response size was
   2894  *    given or if chunked encoding is in use, this will indicate
   2895  *    an error to the client.  Note, however, that if the client
   2896  *    does not know a response size and chunked encoding is not in
   2897  *    use, then clients will not be able to tell the difference between
   2898  *    #MHD_CONTENT_READER_END_WITH_ERROR and #MHD_CONTENT_READER_END_OF_STREAM.
   2899  *    This is not a limitation of MHD but rather of the HTTP protocol.
   2900  */
   2901 typedef ssize_t
   2902 (*MHD_ContentReaderCallback) (void *cls,
   2903                               uint64_t pos,
   2904                               char *buf,
   2905                               size_t max);
   2906 
   2907 
   2908 /**
   2909  * This method is called by libmicrohttpd if we
   2910  * are done with a content reader.  It should
   2911  * be used to free resources associated with the
   2912  * content reader.
   2913  *
   2914  * @param cls closure
   2915  * @ingroup response
   2916  */
   2917 typedef void
   2918 (*MHD_ContentReaderFreeCallback) (void *cls);
   2919 
   2920 
   2921 /**
   2922  * Iterator over key-value pairs where the value
   2923  * may be made available in increments and/or may
   2924  * not be zero-terminated.  Used for processing
   2925  * POST data.
   2926  *
   2927  * @param cls user-specified closure
   2928  * @param kind type of the value, always #MHD_POSTDATA_KIND when called from MHD
   2929  * @param key 0-terminated key for the value, NULL if not known. This value
   2930  *            is never NULL for url-encoded POST data.
   2931  * @param filename name of the uploaded file, NULL if not known
   2932  * @param content_type mime-type of the data, NULL if not known
   2933  * @param transfer_encoding encoding of the data, NULL if not known
   2934  * @param data pointer to @a size bytes of data at the
   2935  *              specified offset
   2936  * @param off offset of data in the overall value
   2937  * @param size number of bytes in @a data available
   2938  * @return #MHD_YES to continue iterating,
   2939  *         #MHD_NO to abort the iteration
   2940  */
   2941 typedef enum MHD_Result
   2942 (*MHD_PostDataIterator)(void *cls,
   2943                         enum MHD_ValueKind kind,
   2944                         const char *key,
   2945                         const char *filename,
   2946                         const char *content_type,
   2947                         const char *transfer_encoding,
   2948                         const char *data,
   2949                         uint64_t off,
   2950                         size_t size);
   2951 
   2952 /* **************** Daemon handling functions ***************** */
   2953 
   2954 /**
   2955  * Start a webserver on the given port.
   2956  *
   2957  * @param flags combination of `enum MHD_FLAG` values
   2958  * @param port port to bind to (in host byte order),
   2959  *        use '0' to bind to random free port,
   2960  *        ignored if MHD_OPTION_SOCK_ADDR or
   2961  *        MHD_OPTION_LISTEN_SOCKET is provided
   2962  *        or MHD_USE_NO_LISTEN_SOCKET is specified
   2963  * @param apc callback to call to check which clients
   2964  *        will be allowed to connect; you can pass NULL
   2965  *        in which case connections from any IP will be
   2966  *        accepted
   2967  * @param apc_cls extra argument to apc
   2968  * @param dh handler called for all requests (repeatedly)
   2969  * @param dh_cls extra argument to @a dh
   2970  * @param ap list of options (type-value pairs,
   2971  *        terminated with #MHD_OPTION_END).
   2972  * @return NULL on error, handle to daemon on success
   2973  * @ingroup event
   2974  */
   2975 _MHD_EXTERN struct MHD_Daemon *
   2976 MHD_start_daemon_va (unsigned int flags,
   2977                      uint16_t port,
   2978                      MHD_AcceptPolicyCallback apc, void *apc_cls,
   2979                      MHD_AccessHandlerCallback dh, void *dh_cls,
   2980                      va_list ap);
   2981 
   2982 
   2983 /**
   2984  * Start a webserver on the given port.  Variadic version of
   2985  * #MHD_start_daemon_va.
   2986  *
   2987  * @param flags combination of `enum MHD_FLAG` values
   2988  * @param port port to bind to (in host byte order),
   2989  *        use '0' to bind to random free port,
   2990  *        ignored if MHD_OPTION_SOCK_ADDR or
   2991  *        MHD_OPTION_LISTEN_SOCKET is provided
   2992  *        or MHD_USE_NO_LISTEN_SOCKET is specified
   2993  * @param apc callback to call to check which clients
   2994  *        will be allowed to connect; you can pass NULL
   2995  *        in which case connections from any IP will be
   2996  *        accepted
   2997  * @param apc_cls extra argument to apc
   2998  * @param dh handler called for all requests (repeatedly)
   2999  * @param dh_cls extra argument to @a dh
   3000  * @return NULL on error, handle to daemon on success
   3001  * @ingroup event
   3002  */
   3003 _MHD_EXTERN struct MHD_Daemon *
   3004 MHD_start_daemon (unsigned int flags,
   3005                   uint16_t port,
   3006                   MHD_AcceptPolicyCallback apc, void *apc_cls,
   3007                   MHD_AccessHandlerCallback dh, void *dh_cls,
   3008                   ...);
   3009 
   3010 
   3011 /**
   3012  * Stop accepting connections from the listening socket.  Allows
   3013  * clients to continue processing, but stops accepting new
   3014  * connections.  Note that the caller is responsible for closing the
   3015  * returned socket; however, if MHD is run using threads (anything but
   3016  * "external" sockets polling mode), it must not be closed until AFTER
   3017  * #MHD_stop_daemon has been called (as it is theoretically possible
   3018  * that an existing thread is still using it).
   3019  *
   3020  * Note that some thread modes require the caller to have passed
   3021  * #MHD_USE_ITC when using this API.  If this daemon is
   3022  * in one of those modes and this option was not given to
   3023  * #MHD_start_daemon, this function will return #MHD_INVALID_SOCKET.
   3024  *
   3025  * @param daemon daemon to stop accepting new connections for
   3026  * @return old listen socket on success, #MHD_INVALID_SOCKET if
   3027  *         the daemon was already not listening anymore
   3028  * @ingroup specialized
   3029  */
   3030 _MHD_EXTERN MHD_socket
   3031 MHD_quiesce_daemon (struct MHD_Daemon *daemon);
   3032 
   3033 
   3034 /**
   3035  * Shutdown an HTTP daemon.
   3036  *
   3037  * @param daemon daemon to stop
   3038  * @ingroup event
   3039  */
   3040 _MHD_EXTERN void
   3041 MHD_stop_daemon (struct MHD_Daemon *daemon);
   3042 
   3043 
   3044 /**
   3045  * Add another client connection to the set of connections managed by
   3046  * MHD.  This API is usually not needed (since MHD will accept inbound
   3047  * connections on the server socket).  Use this API in special cases,
   3048  * for example if your HTTP server is behind NAT and needs to connect
   3049  * out to the HTTP client, or if you are building a proxy.
   3050  *
   3051  * If you use this API in conjunction with an "internal" socket polling,
   3052  * you must set the option #MHD_USE_ITC to ensure that the freshly added
   3053  * connection is immediately processed by MHD.
   3054  *
   3055  * The given client socket will be managed (and closed!) by MHD after
   3056  * this call and must no longer be used directly by the application
   3057  * afterwards.
   3058  *
   3059  * @param daemon daemon that manages the connection
   3060  * @param client_socket socket to manage (MHD will expect
   3061  *        to receive an HTTP request from this socket next).
   3062  * @param addr IP address of the client
   3063  * @param addrlen number of bytes in @a addr
   3064  * @return #MHD_YES on success, #MHD_NO if this daemon could
   3065  *        not handle the connection (i.e. `malloc()` failed, etc).
   3066  *        The socket will be closed in any case; `errno` is
   3067  *        set to indicate further details about the error.
   3068  * @ingroup specialized
   3069  */
   3070 _MHD_EXTERN enum MHD_Result
   3071 MHD_add_connection (struct MHD_Daemon *daemon,
   3072                     MHD_socket client_socket,
   3073                     const struct sockaddr *addr,
   3074                     socklen_t addrlen);
   3075 
   3076 
   3077 /**
   3078  * Obtain the `select()` sets for this daemon.
   3079  * Daemon's FDs will be added to fd_sets. To get only
   3080  * daemon FDs in fd_sets, call FD_ZERO for each fd_set
   3081  * before calling this function. FD_SETSIZE is assumed
   3082  * to be platform's default.
   3083  *
   3084  * This function should be called only when MHD is configured to
   3085  * use "external" sockets polling with 'select()' or with 'epoll'.
   3086  * In the latter case, it will only add the single 'epoll' file
   3087  * descriptor used by MHD to the sets.
   3088  * It's necessary to use #MHD_get_timeout() to get maximum timeout
   3089  * value for `select()`. Usage of `select()` with indefinite timeout
   3090  * (or timeout larger than returned by #MHD_get_timeout()) will
   3091  * violate MHD API and may results in pending unprocessed data.
   3092  *
   3093  * This function must be called only for daemon started
   3094  * without #MHD_USE_INTERNAL_POLLING_THREAD flag.
   3095  *
   3096  * @param daemon daemon to get sets from
   3097  * @param read_fd_set read set
   3098  * @param write_fd_set write set
   3099  * @param except_fd_set except set
   3100  * @param max_fd increased to largest FD added (if larger
   3101  *               than existing value); can be NULL
   3102  * @return #MHD_YES on success, #MHD_NO if this
   3103  *         daemon was not started with the right
   3104  *         options for this call or any FD didn't
   3105  *         fit fd_set.
   3106  * @ingroup event
   3107  */
   3108 _MHD_EXTERN enum MHD_Result
   3109 MHD_get_fdset (struct MHD_Daemon *daemon,
   3110                fd_set *read_fd_set,
   3111                fd_set *write_fd_set,
   3112                fd_set *except_fd_set,
   3113                MHD_socket *max_fd);
   3114 
   3115 
   3116 /**
   3117  * Obtain the `select()` sets for this daemon.
   3118  * Daemon's FDs will be added to fd_sets. To get only
   3119  * daemon FDs in fd_sets, call FD_ZERO for each fd_set
   3120  * before calling this function.
   3121  *
   3122  * Passing custom FD_SETSIZE as @a fd_setsize allow usage of
   3123  * larger/smaller than platform's default fd_sets.
   3124  *
   3125  * This function should be called only when MHD is configured to
   3126  * use "external" sockets polling with 'select()' or with 'epoll'.
   3127  * In the latter case, it will only add the single 'epoll' file
   3128  * descriptor used by MHD to the sets.
   3129  * It's necessary to use #MHD_get_timeout() to get maximum timeout
   3130  * value for `select()`. Usage of `select()` with indefinite timeout
   3131  * (or timeout larger than returned by #MHD_get_timeout()) will
   3132  * violate MHD API and may results in pending unprocessed data.
   3133  *
   3134  * This function must be called only for daemon started
   3135  * without #MHD_USE_INTERNAL_POLLING_THREAD flag.
   3136  *
   3137  * @param daemon daemon to get sets from
   3138  * @param read_fd_set read set
   3139  * @param write_fd_set write set
   3140  * @param except_fd_set except set
   3141  * @param max_fd increased to largest FD added (if larger
   3142  *               than existing value); can be NULL
   3143  * @param fd_setsize value of FD_SETSIZE
   3144  * @return #MHD_YES on success, #MHD_NO if this
   3145  *         daemon was not started with the right
   3146  *         options for this call or any FD didn't
   3147  *         fit fd_set.
   3148  * @ingroup event
   3149  */
   3150 _MHD_EXTERN enum MHD_Result
   3151 MHD_get_fdset2 (struct MHD_Daemon *daemon,
   3152                 fd_set *read_fd_set,
   3153                 fd_set *write_fd_set,
   3154                 fd_set *except_fd_set,
   3155                 MHD_socket *max_fd,
   3156                 unsigned int fd_setsize);
   3157 
   3158 
   3159 /**
   3160  * Obtain the `select()` sets for this daemon.
   3161  * Daemon's FDs will be added to fd_sets. To get only
   3162  * daemon FDs in fd_sets, call FD_ZERO for each fd_set
   3163  * before calling this function. Size of fd_set is
   3164  * determined by current value of FD_SETSIZE.
   3165  *
   3166  * This function should be called only when MHD is configured to
   3167  * use "external" sockets polling with 'select()' or with 'epoll'.
   3168  * In the latter case, it will only add the single 'epoll' file
   3169  * descriptor used by MHD to the sets.
   3170  * It's necessary to use #MHD_get_timeout() to get maximum timeout
   3171  * value for `select()`. Usage of `select()` with indefinite timeout
   3172  * (or timeout larger than returned by #MHD_get_timeout()) will
   3173  * violate MHD API and may results in pending unprocessed data.
   3174  *
   3175  * This function must be called only for daemon started
   3176  * without #MHD_USE_INTERNAL_POLLING_THREAD flag.
   3177  *
   3178  * @param daemon daemon to get sets from
   3179  * @param read_fd_set read set
   3180  * @param write_fd_set write set
   3181  * @param except_fd_set except set
   3182  * @param max_fd increased to largest FD added (if larger
   3183  *               than existing value); can be NULL
   3184  * @return #MHD_YES on success, #MHD_NO if this
   3185  *         daemon was not started with the right
   3186  *         options for this call or any FD didn't
   3187  *         fit fd_set.
   3188  * @ingroup event
   3189  */
   3190 #define MHD_get_fdset(daemon,read_fd_set,write_fd_set,except_fd_set,max_fd) \
   3191         MHD_get_fdset2 ((daemon),(read_fd_set),(write_fd_set),(except_fd_set), \
   3192                         (max_fd),FD_SETSIZE)
   3193 
   3194 
   3195 /**
   3196  * Obtain timeout value for polling function for this daemon.
   3197  *
   3198  * This function set value to the amount of milliseconds for which polling
   3199  * function (`select()`, `poll()` or epoll) should at most block, not the
   3200  * timeout value set for connections.
   3201  *
   3202  * Any "external" sockets polling function must be called with the timeout
   3203  * value provided by this function. Smaller timeout values can be used for
   3204  * polling function if it is required for any reason, but using larger
   3205  * timeout value or no timeout (indefinite timeout) when this function
   3206  * return #MHD_YES will break MHD processing logic and result in "hung"
   3207  * connections with data pending in network buffers and other problems.
   3208  *
   3209  * It is important to always use this function (or #MHD_get_timeout64(),
   3210  * #MHD_get_timeout64s(), #MHD_get_timeout_i() functions) when "external"
   3211  * polling is used.
   3212  * If this function returns #MHD_YES then #MHD_run() (or #MHD_run_from_select())
   3213  * must be called right after return from polling function, regardless of
   3214  * the states of MHD FDs.
   3215  *
   3216  * In practice, if #MHD_YES is returned then #MHD_run() (or
   3217  * #MHD_run_from_select()) must be called not later than @a timeout
   3218  * millisecond even if no activity is detected on sockets by sockets
   3219  * polling function.
   3220  *
   3221  * @param daemon daemon to query for timeout
   3222  * @param[out] timeout set to the timeout (in milliseconds)
   3223  * @return #MHD_YES on success, #MHD_NO if timeouts are
   3224  *         not used and no data processing is pending.
   3225  * @ingroup event
   3226  */
   3227 _MHD_EXTERN enum MHD_Result
   3228 MHD_get_timeout (struct MHD_Daemon *daemon,
   3229                  MHD_UNSIGNED_LONG_LONG *timeout);
   3230 
   3231 
   3232 /**
   3233  * Free the memory allocated by MHD.
   3234  *
   3235  * If any MHD function explicitly mentions that returned pointer must be
   3236  * freed by this function, then no other method must be used to free
   3237  * the memory.
   3238  *
   3239  * @param ptr the pointer to free.
   3240  * @sa #MHD_digest_auth_get_username(), #MHD_basic_auth_get_username_password3()
   3241  * @sa #MHD_basic_auth_get_username_password()
   3242  * @note Available since #MHD_VERSION 0x00095600
   3243  * @ingroup specialized
   3244  */
   3245 _MHD_EXTERN void
   3246 MHD_free (void *ptr);
   3247 
   3248 /**
   3249  * Obtain timeout value for external polling function for this daemon.
   3250  *
   3251  * This function set value to the amount of milliseconds for which polling
   3252  * function (`select()`, `poll()` or epoll) should at most block, not the
   3253  * timeout value set for connections.
   3254  *
   3255  * Any "external" sockets polling function must be called with the timeout
   3256  * value provided by this function. Smaller timeout values can be used for
   3257  * polling function if it is required for any reason, but using larger
   3258  * timeout value or no timeout (indefinite timeout) when this function
   3259  * return #MHD_YES will break MHD processing logic and result in "hung"
   3260  * connections with data pending in network buffers and other problems.
   3261  *
   3262  * It is important to always use this function (or #MHD_get_timeout(),
   3263  * #MHD_get_timeout64s(), #MHD_get_timeout_i() functions) when "external"
   3264  * polling is used.
   3265  * If this function returns #MHD_YES then #MHD_run() (or #MHD_run_from_select())
   3266  * must be called right after return from polling function, regardless of
   3267  * the states of MHD FDs.
   3268  *
   3269  * In practice, if #MHD_YES is returned then #MHD_run() (or
   3270  * #MHD_run_from_select()) must be called not later than @a timeout
   3271  * millisecond even if no activity is detected on sockets by sockets
   3272  * polling function.
   3273  *
   3274  * @param daemon daemon to query for timeout
   3275  * @param[out] timeout64 the pointer to the variable to be set to the
   3276  *                  timeout (in milliseconds)
   3277  * @return #MHD_YES if timeout value has been set,
   3278  *         #MHD_NO if timeouts are not used and no data processing is pending.
   3279  * @note Available since #MHD_VERSION 0x00097701
   3280  * @ingroup event
   3281  */
   3282 _MHD_EXTERN enum MHD_Result
   3283 MHD_get_timeout64 (struct MHD_Daemon *daemon,
   3284                    uint64_t *timeout);
   3285 
   3286 
   3287 /**
   3288  * Obtain timeout value for external polling function for this daemon.
   3289  *
   3290  * This function set value to the amount of milliseconds for which polling
   3291  * function (`select()`, `poll()` or epoll) should at most block, not the
   3292  * timeout value set for connections.
   3293  *
   3294  * Any "external" sockets polling function must be called with the timeout
   3295  * value provided by this function (if returned value is non-negative).
   3296  * Smaller timeout values can be used for polling function if it is required
   3297  * for any reason, but using larger timeout value or no timeout (indefinite
   3298  * timeout) when this function returns non-negative value will break MHD
   3299  * processing logic and result in "hung" connections with data pending in
   3300  * network buffers and other problems.
   3301  *
   3302  * It is important to always use this function (or #MHD_get_timeout(),
   3303  * #MHD_get_timeout64(), #MHD_get_timeout_i() functions) when "external"
   3304  * polling is used.
   3305  * If this function returns non-negative value then #MHD_run() (or
   3306  * #MHD_run_from_select()) must be called right after return from polling
   3307  * function, regardless of the states of MHD FDs.
   3308  *
   3309  * In practice, if zero or positive value is returned then #MHD_run() (or
   3310  * #MHD_run_from_select()) must be called not later than returned amount of
   3311  * millisecond even if no activity is detected on sockets by sockets
   3312  * polling function.
   3313  *
   3314  * @param daemon the daemon to query for timeout
   3315  * @return -1 if connections' timeouts are not set and no data processing
   3316  *         is pending, so external polling function may wait for sockets
   3317  *         activity for indefinite amount of time,
   3318  *         otherwise returned value is the the maximum amount of millisecond
   3319  *         that external polling function must wait for the activity of FDs.
   3320  * @note Available since #MHD_VERSION 0x00097701
   3321  * @ingroup event
   3322  */
   3323 _MHD_EXTERN int64_t
   3324 MHD_get_timeout64s (struct MHD_Daemon *daemon);
   3325 
   3326 
   3327 /**
   3328  * Obtain timeout value for external polling function for this daemon.
   3329  *
   3330  * This function set value to the amount of milliseconds for which polling
   3331  * function (`select()`, `poll()` or epoll) should at most block, not the
   3332  * timeout value set for connections.
   3333  *
   3334  * Any "external" sockets polling function must be called with the timeout
   3335  * value provided by this function (if returned value is non-negative).
   3336  * Smaller timeout values can be used for polling function if it is required
   3337  * for any reason, but using larger timeout value or no timeout (indefinite
   3338  * timeout) when this function returns non-negative value will break MHD
   3339  * processing logic and result in "hung" connections with data pending in
   3340  * network buffers and other problems.
   3341  *
   3342  * It is important to always use this function (or #MHD_get_timeout(),
   3343  * #MHD_get_timeout64(), #MHD_get_timeout64s() functions) when "external"
   3344  * polling is used.
   3345  * If this function returns non-negative value then #MHD_run() (or
   3346  * #MHD_run_from_select()) must be called right after return from polling
   3347  * function, regardless of the states of MHD FDs.
   3348  *
   3349  * In practice, if zero or positive value is returned then #MHD_run() (or
   3350  * #MHD_run_from_select()) must be called not later than returned amount of
   3351  * millisecond even if no activity is detected on sockets by sockets
   3352  * polling function.
   3353  *
   3354  * @param daemon the daemon to query for timeout
   3355  * @return -1 if connections' timeouts are not set and no data processing
   3356  *         is pending, so external polling function may wait for sockets
   3357  *         activity for indefinite amount of time,
   3358  *         otherwise returned value is the the maximum amount of millisecond
   3359  *         (capped at INT_MAX) that external polling function must wait
   3360  *         for the activity of FDs.
   3361  * @note Available since #MHD_VERSION 0x00097701
   3362  * @ingroup event
   3363  */
   3364 _MHD_EXTERN int
   3365 MHD_get_timeout_i (struct MHD_Daemon *daemon);
   3366 
   3367 
   3368 /**
   3369  * Run webserver operations (without blocking unless in client callbacks).
   3370  *
   3371  * This method should be called by clients in combination with
   3372  * #MHD_get_fdset() (or #MHD_get_daemon_info() with MHD_DAEMON_INFO_EPOLL_FD
   3373  * if epoll is used) and #MHD_get_timeout() if the client-controlled
   3374  * connection polling method is used (i.e. daemon was started without
   3375  * #MHD_USE_INTERNAL_POLLING_THREAD flag).
   3376  *
   3377  * This function is a convenience method, which is useful if the
   3378  * fd_sets from #MHD_get_fdset were not directly passed to `select()`;
   3379  * with this function, MHD will internally do the appropriate `select()`
   3380  * call itself again.  While it is acceptable to call #MHD_run (if
   3381  * #MHD_USE_INTERNAL_POLLING_THREAD is not set) at any moment, you should
   3382  * call #MHD_run_from_select() if performance is important (as it saves an
   3383  * expensive call to `select()`).
   3384  *
   3385  * If #MHD_get_timeout() returned #MHD_YES, than this function must be called
   3386  * right after polling function returns regardless of detected activity on
   3387  * the daemon's FDs.
   3388  *
   3389  * @param daemon daemon to run
   3390  * @return #MHD_YES on success, #MHD_NO if this
   3391  *         daemon was not started with the right
   3392  *         options for this call.
   3393  * @ingroup event
   3394  */
   3395 _MHD_EXTERN enum MHD_Result
   3396 MHD_run (struct MHD_Daemon *daemon);
   3397 
   3398 
   3399 /**
   3400  * Run websever operation with possible blocking.
   3401  *
   3402  * This function does the following: waits for any network event not more than
   3403  * specified number of milliseconds, processes all incoming and outgoing data,
   3404  * processes new connections, processes any timed-out connection, and does
   3405  * other things required to run webserver.
   3406  * Once all connections are processed, function returns.
   3407  *
   3408  * This function is useful for quick and simple (lazy) webserver implementation
   3409  * if application needs to run a single thread only and does not have any other
   3410  * network activity.
   3411  *
   3412  * This function calls MHD_get_timeout() internally and use returned value as
   3413  * maximum wait time if it less than value of @a millisec parameter.
   3414  *
   3415  * It is expected that the "external" socket polling function is not used in
   3416  * conjunction with this function unless the @a millisec is set to zero.
   3417  *
   3418  * @param daemon the daemon to run
   3419  * @param millisec the maximum time in milliseconds to wait for network and
   3420  *                 other events. Note: there is no guarantee that function
   3421  *                 blocks for the specified amount of time. The real processing
   3422  *                 time can be shorter (if some data or connection timeout
   3423  *                 comes earlier) or longer (if data processing requires more
   3424  *                 time, especially in user callbacks).
   3425  *                 If set to '0' then function does not block and processes
   3426  *                 only already available data (if any).
   3427  *                 If set to '-1' then function waits for events
   3428  *                 indefinitely (blocks until next network activity or
   3429  *                 connection timeout).
   3430  * @return #MHD_YES on success, #MHD_NO if this
   3431  *         daemon was not started with the right
   3432  *         options for this call or some serious
   3433  *         unrecoverable error occurs.
   3434  * @note Available since #MHD_VERSION 0x00097206
   3435  * @ingroup event
   3436  */
   3437 _MHD_EXTERN enum MHD_Result
   3438 MHD_run_wait (struct MHD_Daemon *daemon,
   3439               int32_t millisec);
   3440 
   3441 
   3442 /**
   3443  * Run webserver operations. This method should be called by clients
   3444  * in combination with #MHD_get_fdset and #MHD_get_timeout() if the
   3445  * client-controlled select method is used.
   3446  *
   3447  * You can use this function instead of #MHD_run if you called
   3448  * `select()` on the result from #MHD_get_fdset.  File descriptors in
   3449  * the sets that are not controlled by MHD will be ignored.  Calling
   3450  * this function instead of #MHD_run is more efficient as MHD will
   3451  * not have to call `select()` again to determine which operations are
   3452  * ready.
   3453  *
   3454  * If #MHD_get_timeout() returned #MHD_YES, than this function must be
   3455  * called right after `select()` returns regardless of detected activity
   3456  * on the daemon's FDs.
   3457  *
   3458  * This function cannot be used with daemon started with
   3459  * #MHD_USE_INTERNAL_POLLING_THREAD flag.
   3460  *
   3461  * @param daemon daemon to run select loop for
   3462  * @param read_fd_set read set
   3463  * @param write_fd_set write set
   3464  * @param except_fd_set except set
   3465  * @return #MHD_NO on serious errors, #MHD_YES on success
   3466  * @ingroup event
   3467  */
   3468 _MHD_EXTERN enum MHD_Result
   3469 MHD_run_from_select (struct MHD_Daemon *daemon,
   3470                      const fd_set *read_fd_set,
   3471                      const fd_set *write_fd_set,
   3472                      const fd_set *except_fd_set);
   3473 
   3474 
   3475 /**
   3476  * Run webserver operations. This method should be called by clients
   3477  * in combination with #MHD_get_fdset and #MHD_get_timeout() if the
   3478  * client-controlled select method is used.
   3479  * This function specifies FD_SETSIZE used when provided fd_sets were
   3480  * created. It is important on platforms where FD_SETSIZE can be
   3481  * overridden.
   3482  *
   3483  * You can use this function instead of #MHD_run if you called
   3484  * 'select()' on the result from #MHD_get_fdset2().  File descriptors in
   3485  * the sets that are not controlled by MHD will be ignored.  Calling
   3486  * this function instead of #MHD_run() is more efficient as MHD will
   3487  * not have to call 'select()' again to determine which operations are
   3488  * ready.
   3489  *
   3490  * If #MHD_get_timeout() returned #MHD_YES, than this function must be
   3491  * called right after 'select()' returns regardless of detected activity
   3492  * on the daemon's FDs.
   3493  *
   3494  * This function cannot be used with daemon started with
   3495  * #MHD_USE_INTERNAL_POLLING_THREAD flag.
   3496  *
   3497  * @param daemon the daemon to run select loop for
   3498  * @param read_fd_set the read set
   3499  * @param write_fd_set the write set
   3500  * @param except_fd_set the except set
   3501  * @param fd_setsize the value of FD_SETSIZE
   3502  * @return #MHD_NO on serious errors, #MHD_YES on success
   3503  * @sa #MHD_get_fdset2(), #MHD_OPTION_APP_FD_SETSIZE
   3504  * @ingroup event
   3505  */
   3506 _MHD_EXTERN enum MHD_Result
   3507 MHD_run_from_select2 (struct MHD_Daemon *daemon,
   3508                       const fd_set *read_fd_set,
   3509                       const fd_set *write_fd_set,
   3510                       const fd_set *except_fd_set,
   3511                       unsigned int fd_setsize);
   3512 
   3513 
   3514 /**
   3515  * Run webserver operations. This method should be called by clients
   3516  * in combination with #MHD_get_fdset and #MHD_get_timeout() if the
   3517  * client-controlled select method is used.
   3518  * This macro automatically substitutes current FD_SETSIZE value.
   3519  * It is important on platforms where FD_SETSIZE can be overridden.
   3520  *
   3521  * You can use this function instead of #MHD_run if you called
   3522  * 'select()' on the result from #MHD_get_fdset2().  File descriptors in
   3523  * the sets that are not controlled by MHD will be ignored.  Calling
   3524  * this function instead of #MHD_run() is more efficient as MHD will
   3525  * not have to call 'select()' again to determine which operations are
   3526  * ready.
   3527  *
   3528  * If #MHD_get_timeout() returned #MHD_YES, than this function must be
   3529  * called right after 'select()' returns regardless of detected activity
   3530  * on the daemon's FDs.
   3531  *
   3532  * This function cannot be used with daemon started with
   3533  * #MHD_USE_INTERNAL_POLLING_THREAD flag.
   3534  *
   3535  * @param daemon the daemon to run select loop for
   3536  * @param read_fd_set the read set
   3537  * @param write_fd_set the write set
   3538  * @param except_fd_set the except set
   3539  * @param fd_setsize the value of FD_SETSIZE
   3540  * @return #MHD_NO on serious errors, #MHD_YES on success
   3541  * @sa #MHD_get_fdset2(), #MHD_OPTION_APP_FD_SETSIZE
   3542  * @ingroup event
   3543  */
   3544 #define MHD_run_from_select(d,r,w,e) \
   3545         MHD_run_from_select2 ((d),(r),(w),(e),(unsigned int) (FD_SETSIZE))
   3546 
   3547 /* **************** Connection handling functions ***************** */
   3548 
   3549 
   3550 /**
   3551  * Get request URI path (the request target without query part).
   3552  *
   3553  * The value obtained by this function is the same value as @a url provided
   3554  * for #MHD_AccessHandlerCallback callback, but this function also provides
   3555  * the size of the string.
   3556  *
   3557  * This function is critically important when binary zero is allowed by daemon
   3558  * option #MHD_OPTION_ALLOW_BIN_ZERO_IN_URI_PATH as this is the only way to
   3559  * get the non-truncated request URI.
   3560  *
   3561  * Returned @a uri pointer is valid until response is started or connection
   3562  * is terminated.
   3563  *
   3564  * @param connection the connection to URI from
   3565  * @param[out] uri set to the request URI without query part, may contain
   3566  *                 binary zeros (NUL) characters, never set to NULL on
   3567  *                 success; can be NULL
   3568  * @param[out] uri_size set to the size of the @a uri in bytes, not including
   3569  *                       final zero-termination; can be NULL
   3570  * @return #MHD_NO if failed (request is not yet processed or response has
   3571  *                 been queued already);
   3572  *         #MHD_YES on success (*uri set to valid pointer)
   3573  * @note Available since #MHD_VERSION 0x01000201
   3574  * @sa #MHD_OPTION_ALLOW_BIN_ZERO_IN_URI_PATH, #MHD_AccessHandlerCallback
   3575  * @ingroup request
   3576  */
   3577 _MHD_EXTERN enum MHD_Result
   3578 MHD_get_connection_URI_path_n (struct MHD_Connection *connection,
   3579                                const char **uri,
   3580                                size_t *uri_size);
   3581 
   3582 /**
   3583  * Get all of the headers from the request.
   3584  *
   3585  * @param connection connection to get values from
   3586  * @param kind types of values to iterate over, can be a bitmask
   3587  * @param iterator callback to call on each header;
   3588  *        may be NULL (then just count headers)
   3589  * @param iterator_cls extra argument to @a iterator
   3590  * @return number of entries iterated over,
   3591  *         -1 if connection is NULL.
   3592  * @ingroup request
   3593  */
   3594 _MHD_EXTERN int
   3595 MHD_get_connection_values (struct MHD_Connection *connection,
   3596                            enum MHD_ValueKind kind,
   3597                            MHD_KeyValueIterator iterator,
   3598                            void *iterator_cls);
   3599 
   3600 
   3601 /**
   3602  * Get all of the headers from the request.
   3603  *
   3604  * @param connection connection to get values from
   3605  * @param kind types of values to iterate over, can be a bitmask
   3606  * @param iterator callback to call on each header;
   3607  *        may be NULL (then just count headers)
   3608  * @param iterator_cls extra argument to @a iterator
   3609  * @return number of entries iterated over,
   3610  *         -1 if connection is NULL.
   3611  * @note Available since #MHD_VERSION 0x00096400
   3612  * @ingroup request
   3613  */
   3614 _MHD_EXTERN int
   3615 MHD_get_connection_values_n (struct MHD_Connection *connection,
   3616                              enum MHD_ValueKind kind,
   3617                              MHD_KeyValueIteratorN iterator,
   3618                              void *iterator_cls);
   3619 
   3620 
   3621 /**
   3622  * This function can be used to add an entry to the HTTP headers of a
   3623  * connection (so that the #MHD_get_connection_values function will
   3624  * return them -- and the `struct MHD_PostProcessor` will also see
   3625  * them).  This maybe required in certain situations (see Mantis
   3626  * #1399) where (broken) HTTP implementations fail to supply values
   3627  * needed by the post processor (or other parts of the application).
   3628  *
   3629  * This function MUST only be called from within the
   3630  * #MHD_AccessHandlerCallback (otherwise, access maybe improperly
   3631  * synchronized).  Furthermore, the client must guarantee that the key
   3632  * and value arguments are 0-terminated strings that are NOT freed
   3633  * until the connection is closed.  (The easiest way to do this is by
   3634  * passing only arguments to permanently allocated strings.).
   3635  *
   3636  * @param connection the connection for which a
   3637  *  value should be set
   3638  * @param kind kind of the value
   3639  * @param key key for the value
   3640  * @param value the value itself
   3641  * @return #MHD_NO if the operation could not be
   3642  *         performed due to insufficient memory;
   3643  *         #MHD_YES on success
   3644  * @ingroup request
   3645  */
   3646 _MHD_EXTERN enum MHD_Result
   3647 MHD_set_connection_value (struct MHD_Connection *connection,
   3648                           enum MHD_ValueKind kind,
   3649                           const char *key,
   3650                           const char *value);
   3651 
   3652 
   3653 /**
   3654  * This function can be used to add an arbitrary entry to connection.
   3655  * This function could add entry with binary zero, which is allowed
   3656  * for #MHD_GET_ARGUMENT_KIND. For other kind on entries it is
   3657  * recommended to use #MHD_set_connection_value.
   3658  *
   3659  * This function MUST only be called from within the
   3660  * #MHD_AccessHandlerCallback (otherwise, access maybe improperly
   3661  * synchronized).  Furthermore, the client must guarantee that the key
   3662  * and value arguments are 0-terminated strings that are NOT freed
   3663  * until the connection is closed.  (The easiest way to do this is by
   3664  * passing only arguments to permanently allocated strings.).
   3665  *
   3666  * @param connection the connection for which a
   3667  *  value should be set
   3668  * @param kind kind of the value
   3669  * @param key key for the value, must be zero-terminated
   3670  * @param key_size number of bytes in @a key (excluding 0-terminator)
   3671  * @param value the value itself, must be zero-terminated
   3672  * @param value_size number of bytes in @a value (excluding 0-terminator)
   3673  * @return #MHD_NO if the operation could not be
   3674  *         performed due to insufficient memory;
   3675  *         #MHD_YES on success
   3676  * @note Available since #MHD_VERSION 0x00096400
   3677  * @ingroup request
   3678  */
   3679 _MHD_EXTERN enum MHD_Result
   3680 MHD_set_connection_value_n (struct MHD_Connection *connection,
   3681                             enum MHD_ValueKind kind,
   3682                             const char *key,
   3683                             size_t key_size,
   3684                             const char *value,
   3685                             size_t value_size);
   3686 
   3687 
   3688 /**
   3689  * Sets the global error handler to a different implementation.
   3690  *
   3691  * @a cb will only be called in the case of typically fatal, serious internal
   3692  * consistency issues or serious system failures like failed lock of mutex.
   3693  *
   3694  * These issues should only arise in the case of serious memory corruption or
   3695  * similar problems with the architecture, there is no safe way to continue
   3696  * even for closing of the application.
   3697  *
   3698  * The default implementation that is used if no panic function is set simply
   3699  * prints an error message and calls `abort()`.
   3700  * Alternative implementations might call `exit()` or other similar functions.
   3701  *
   3702  * @param cb new error handler or NULL to use default handler
   3703  * @param cls passed to @a cb
   3704  * @ingroup logging
   3705  */
   3706 _MHD_EXTERN void
   3707 MHD_set_panic_func (MHD_PanicCallback cb, void *cls);
   3708 
   3709 
   3710 /**
   3711  * Process escape sequences ('%HH') Updates val in place; the
   3712  * result cannot be larger than the input.
   3713  * The result is still be 0-terminated.
   3714  *
   3715  * @param val value to unescape (modified in the process)
   3716  * @return length of the resulting val (`strlen(val)` may be
   3717  *  shorter afterwards due to elimination of escape sequences)
   3718  */
   3719 _MHD_EXTERN size_t
   3720 MHD_http_unescape (char *val);
   3721 
   3722 
   3723 /**
   3724  * Get a particular header value.  If multiple
   3725  * values match the kind, return any one of them.
   3726  *
   3727  * @param connection connection to get values from
   3728  * @param kind what kind of value are we looking for
   3729  * @param key the header to look for, NULL to lookup 'trailing' value without a key
   3730  * @return NULL if no such item was found
   3731  * @ingroup request
   3732  */
   3733 _MHD_EXTERN const char *
   3734 MHD_lookup_connection_value (struct MHD_Connection *connection,
   3735                              enum MHD_ValueKind kind,
   3736                              const char *key);
   3737 
   3738 
   3739 /**
   3740  * Get a particular header value.  If multiple
   3741  * values match the kind, return any one of them.
   3742  * @note Since MHD_VERSION 0x00096304
   3743  *
   3744  * @param connection connection to get values from
   3745  * @param kind what kind of value are we looking for
   3746  * @param key the header to look for, NULL to lookup 'trailing' value without a key
   3747  * @param key_size the length of @a key in bytes
   3748  * @param[out] value_ptr the pointer to variable, which will be set to found value,
   3749  *                       will not be updated if key not found,
   3750  *                       could be NULL to just check for presence of @a key
   3751  * @param[out] value_size_ptr the pointer variable, which will set to found value,
   3752  *                            will not be updated if key not found,
   3753  *                            could be NULL
   3754  * @return #MHD_YES if key is found,
   3755  *         #MHD_NO otherwise.
   3756  * @ingroup request
   3757  */
   3758 _MHD_EXTERN enum MHD_Result
   3759 MHD_lookup_connection_value_n (struct MHD_Connection *connection,
   3760                                enum MHD_ValueKind kind,
   3761                                const char *key,
   3762                                size_t key_size,
   3763                                const char **value_ptr,
   3764                                size_t *value_size_ptr);
   3765 
   3766 
   3767 /**
   3768  * Queue a response to be transmitted to the client (as soon as
   3769  * possible but after #MHD_AccessHandlerCallback returns).
   3770  *
   3771  * For any active connection this function must be called
   3772  * only by #MHD_AccessHandlerCallback callback.
   3773  *
   3774  * For suspended connection this function can be called at any moment (this
   3775  * behaviour is deprecated and will be removed!). Response  will be sent
   3776  * as soon as connection is resumed.
   3777  *
   3778  * For single thread environment, when MHD is used in "external polling" mode
   3779  * (without MHD_USE_SELECT_INTERNALLY) this function can be called any
   3780  * time (this behaviour is deprecated and will be removed!).
   3781  *
   3782  * If HTTP specifications require use no body in reply, like @a status_code with
   3783  * value 1xx, the response body is automatically not sent even if it is present
   3784  * in the response. No "Content-Length" or "Transfer-Encoding" headers are
   3785  * generated and added.
   3786  *
   3787  * When the response is used to respond HEAD request or used with @a status_code
   3788  * #MHD_HTTP_NOT_MODIFIED, then response body is not sent, but "Content-Length"
   3789  * header is added automatically based the size of the body in the response.
   3790  * If body size it set to #MHD_SIZE_UNKNOWN or chunked encoding is enforced
   3791  * then "Transfer-Encoding: chunked" header (for HTTP/1.1 only) is added instead
   3792  * of "Content-Length" header. For example, if response with zero-size body is
   3793  * used for HEAD request, then "Content-Length: 0" is added automatically to
   3794  * reply headers.
   3795  * @sa #MHD_RF_HEAD_ONLY_RESPONSE
   3796  *
   3797  * In situations, where reply body is required, like answer for the GET request
   3798  * with @a status_code #MHD_HTTP_OK, headers "Content-Length" (for known body
   3799  * size) or "Transfer-Encoding: chunked" (for #MHD_SIZE_UNKNOWN with HTTP/1.1)
   3800  * are added automatically.
   3801  * In practice, the same response object can be used to respond to both HEAD and
   3802  * GET requests.
   3803  *
   3804  * @param connection the connection identifying the client
   3805  * @param status_code HTTP status code (i.e. #MHD_HTTP_OK)
   3806  * @param response response to transmit, the NULL is tolerated
   3807  * @return #MHD_NO on error (reply already sent, response is NULL),
   3808  *         #MHD_YES on success or if message has been queued
   3809  * @ingroup response
   3810  * @sa #MHD_AccessHandlerCallback
   3811  */
   3812 _MHD_EXTERN enum MHD_Result
   3813 MHD_queue_response (struct MHD_Connection *connection,
   3814                     unsigned int status_code,
   3815                     struct MHD_Response *response);
   3816 
   3817 
   3818 /**
   3819  * Suspend handling of network data for a given connection.
   3820  * This can be used to dequeue a connection from MHD's event loop
   3821  * (not applicable to thread-per-connection!) for a while.
   3822  *
   3823  * If you use this API in conjunction with an "internal" socket polling,
   3824  * you must set the option #MHD_USE_ITC to ensure that a resumed
   3825  * connection is immediately processed by MHD.
   3826  *
   3827  * Suspended connections continue to count against the total number of
   3828  * connections allowed (per daemon, as well as per IP, if such limits
   3829  * are set).  Suspended connections will NOT time out; timeouts will
   3830  * restart when the connection handling is resumed.  While a
   3831  * connection is suspended, MHD will not detect disconnects by the
   3832  * client.
   3833  *
   3834  * The only safe way to call this function is to call it from the
   3835  * #MHD_AccessHandlerCallback or #MHD_ContentReaderCallback.
   3836  *
   3837  * Finally, it is an API violation to call #MHD_stop_daemon while
   3838  * having suspended connections (this will at least create memory and
   3839  * socket leaks or lead to undefined behavior).  You must explicitly
   3840  * resume all connections before stopping the daemon.
   3841  *
   3842  * @param connection the connection to suspend
   3843  *
   3844  * @sa #MHD_AccessHandlerCallback
   3845  */
   3846 _MHD_EXTERN void
   3847 MHD_suspend_connection (struct MHD_Connection *connection);
   3848 
   3849 
   3850 /**
   3851  * Resume handling of network data for suspended connection.  It is
   3852  * safe to resume a suspended connection at any time.  Calling this
   3853  * function on a connection that was not previously suspended will
   3854  * result in undefined behavior.
   3855  *
   3856  * If you are using this function in "external" sockets polling mode, you must
   3857  * make sure to run #MHD_run() and #MHD_get_timeout() afterwards (before
   3858  * again calling #MHD_get_fdset()), as otherwise the change may not be
   3859  * reflected in the set returned by #MHD_get_fdset() and you may end up
   3860  * with a connection that is stuck until the next network activity.
   3861  *
   3862  * This function may be called from any thread.  In "external" sockets
   3863  * polling mode it writes to the inter-thread communication channel that
   3864  * #MHD_ALLOW_SUSPEND_RESUME sets up, and as #MHD_get_fdset() puts the
   3865  * reading end of that channel into the read set, a call from another
   3866  * thread interrupts a select()/poll() that the application is blocked
   3867  * in.  This matters because #MHD_get_timeout() reports no timeout at
   3868  * all while every connection is suspended, so the application would
   3869  * otherwise block indefinitely.  The channel is level triggered, hence
   3870  * a resume issued between #MHD_get_fdset() and select() cannot be lost.
   3871  *
   3872  * @param connection the connection to resume
   3873  */
   3874 _MHD_EXTERN void
   3875 MHD_resume_connection (struct MHD_Connection *connection);
   3876 
   3877 
   3878 /* **************** Response manipulation functions ***************** */
   3879 
   3880 
   3881 /**
   3882  * Flags for special handling of responses.
   3883  */
   3884 enum MHD_ResponseFlags
   3885 {
   3886   /**
   3887    * Default: no special flags.
   3888    * @note Available since #MHD_VERSION 0x00093701
   3889    */
   3890   MHD_RF_NONE = 0,
   3891 
   3892   /**
   3893    * Only respond in conservative (dumb) HTTP/1.0-compatible mode.
   3894    * Response still use HTTP/1.1 version in header, but always close
   3895    * the connection after sending the response and do not use chunked
   3896    * encoding for the response.
   3897    * You can also set the #MHD_RF_HTTP_1_0_SERVER flag to force
   3898    * HTTP/1.0 version in the response.
   3899    * Responses are still compatible with HTTP/1.1.
   3900    * This option can be used to communicate with some broken client, which
   3901    * does not implement HTTP/1.1 features, but advertises HTTP/1.1 support.
   3902    * @note Available since #MHD_VERSION 0x00097308
   3903    */
   3904   MHD_RF_HTTP_1_0_COMPATIBLE_STRICT = 1 << 0,
   3905   /**
   3906    * The same as #MHD_RF_HTTP_1_0_COMPATIBLE_STRICT
   3907    * @note Available since #MHD_VERSION 0x00093701
   3908    */
   3909   MHD_RF_HTTP_VERSION_1_0_ONLY = 1 << 0,
   3910 
   3911   /**
   3912    * Only respond in HTTP 1.0-mode.
   3913    * Contrary to the #MHD_RF_HTTP_1_0_COMPATIBLE_STRICT flag, the response's
   3914    * HTTP version will always be set to 1.0 and keep-alive connections
   3915    * will be used if explicitly requested by the client.
   3916    * The "Connection:" header will be added for both "close" and "keep-alive"
   3917    * connections.
   3918    * Chunked encoding will not be used for the response.
   3919    * Due to backward compatibility, responses still can be used with
   3920    * HTTP/1.1 clients.
   3921    * This option can be used to emulate HTTP/1.0 server (for response part
   3922    * only as chunked encoding in requests (if any) is processed by MHD).
   3923    * @note Available since #MHD_VERSION 0x00097308
   3924    */
   3925   MHD_RF_HTTP_1_0_SERVER = 1 << 1,
   3926   /**
   3927    * The same as #MHD_RF_HTTP_1_0_SERVER
   3928    * @note Available since #MHD_VERSION 0x00096000
   3929    */
   3930   MHD_RF_HTTP_VERSION_1_0_RESPONSE = 1 << 1,
   3931 
   3932   /**
   3933    * Disable sanity check preventing clients from manually
   3934    * setting the HTTP content length option.
   3935    * Allow to set several "Content-Length" headers. These headers will
   3936    * be used even with replies without body.
   3937    * @note Available since #MHD_VERSION 0x00096702
   3938    */
   3939   MHD_RF_INSANITY_HEADER_CONTENT_LENGTH = 1 << 2,
   3940 
   3941   /**
   3942    * Enable sending of "Connection: keep-alive" header even for
   3943    * HTTP/1.1 clients when "Keep-Alive" connection is used.
   3944    * Disabled by default for HTTP/1.1 clients as per RFC.
   3945    * @note Available since #MHD_VERSION 0x00097310
   3946    */
   3947   MHD_RF_SEND_KEEP_ALIVE_HEADER = 1 << 3,
   3948 
   3949   /**
   3950    * Enable special processing of the response as body-less (with undefined
   3951    * body size). No automatic "Content-Length" or "Transfer-Encoding: chunked"
   3952    * headers are added when the response is used with #MHD_HTTP_NOT_MODIFIED
   3953    * code or to respond to HEAD request.
   3954    * The flag also allow to set arbitrary "Content-Length" by
   3955    * MHD_add_response_header() function.
   3956    * This flag value can be used only with responses created without body
   3957    * (zero-size body).
   3958    * Responses with this flag enabled cannot be used in situations where
   3959    * reply body must be sent to the client.
   3960    * This flag is primarily intended to be used when automatic "Content-Length"
   3961    * header is undesirable in response to HEAD requests.
   3962    * @note Available since #MHD_VERSION 0x00097701
   3963    */
   3964   MHD_RF_HEAD_ONLY_RESPONSE = 1 << 4
   3965 } _MHD_FIXED_FLAGS_ENUM;
   3966 
   3967 
   3968 /**
   3969  * MHD options (for future extensions).
   3970  */
   3971 enum MHD_ResponseOptions
   3972 {
   3973   /**
   3974    * End of the list of options.
   3975    */
   3976   MHD_RO_END = 0
   3977 } _MHD_FIXED_ENUM;
   3978 
   3979 
   3980 /**
   3981  * Set special flags and options for a response.
   3982  *
   3983  * @param response the response to modify
   3984  * @param flags to set for the response
   3985  * @param ... #MHD_RO_END terminated list of options
   3986  * @return #MHD_YES on success, #MHD_NO on error
   3987  */
   3988 _MHD_EXTERN enum MHD_Result
   3989 MHD_set_response_options (struct MHD_Response *response,
   3990                           enum MHD_ResponseFlags flags,
   3991                           ...);
   3992 
   3993 
   3994 /**
   3995  * Create a response object.
   3996  * The response object can be extended with header information and then be used
   3997  * any number of times.
   3998  *
   3999  * If response object is used to answer HEAD request then the body of the
   4000  * response is not used, while all headers (including automatic headers) are
   4001  * used.
   4002  *
   4003  * @param size size of the data portion of the response, #MHD_SIZE_UNKNOWN for unknown
   4004  * @param block_size preferred block size for querying crc (advisory only,
   4005  *                   MHD may still call @a crc using smaller chunks); this
   4006  *                   is essentially the buffer size used for IO, clients
   4007  *                   should pick a value that is appropriate for IO and
   4008  *                   memory performance requirements
   4009  * @param crc callback to use to obtain response data
   4010  * @param crc_cls extra argument to @a crc
   4011  * @param crfc callback to call to free @a crc_cls resources
   4012  * @return NULL on error (i.e. invalid arguments, out of memory)
   4013  * @ingroup response
   4014  */
   4015 _MHD_EXTERN struct MHD_Response *
   4016 MHD_create_response_from_callback (uint64_t size,
   4017                                    size_t block_size,
   4018                                    MHD_ContentReaderCallback crc, void *crc_cls,
   4019                                    MHD_ContentReaderFreeCallback crfc);
   4020 
   4021 
   4022 /**
   4023  * Create a response object.
   4024  * The response object can be extended with header information and then be used
   4025  * any number of times.
   4026  *
   4027  * If response object is used to answer HEAD request then the body of the
   4028  * response is not used, while all headers (including automatic headers) are
   4029  * used.
   4030  *
   4031  * @param size size of the @a data portion of the response
   4032  * @param data the data itself
   4033  * @param must_free libmicrohttpd should free data when done
   4034  * @param must_copy libmicrohttpd must make a copy of @a data
   4035  *        right away, the data may be released anytime after
   4036  *        this call returns
   4037  * @return NULL on error (i.e. invalid arguments, out of memory)
   4038  * @deprecated use #MHD_create_response_from_buffer instead
   4039  * @ingroup response
   4040  */
   4041 _MHD_DEPR_FUNC ( \
   4042   "MHD_create_response_from_data() is deprecated, use MHD_create_response_from_buffer()" \
   4043   ) \
   4044   _MHD_EXTERN struct MHD_Response *
   4045 MHD_create_response_from_data (size_t size,
   4046                                void *data,
   4047                                int must_free,
   4048                                int must_copy);
   4049 
   4050 
   4051 /**
   4052  * Specification for how MHD should treat the memory buffer
   4053  * given for the response.
   4054  * @ingroup response
   4055  */
   4056 enum MHD_ResponseMemoryMode
   4057 {
   4058 
   4059   /**
   4060    * Buffer is a persistent (static/global) buffer that won't change
   4061    * for at least the lifetime of the response, MHD should just use
   4062    * it, not free it, not copy it, just keep an alias to it.
   4063    * @ingroup response
   4064    */
   4065   MHD_RESPMEM_PERSISTENT,
   4066 
   4067   /**
   4068    * Buffer is heap-allocated with `malloc()` (or equivalent) and
   4069    * should be freed by MHD after processing the response has
   4070    * concluded (response reference counter reaches zero).
   4071    * The more portable way to automatically free the buffer is function
   4072    * MHD_create_response_from_buffer_with_free_callback() with '&free' as
   4073    * crfc parameter as it does not require to use the same runtime library.
   4074    * @warning It is critical to make sure that the same C-runtime library
   4075    *          is used by both application and MHD (especially
   4076    *          important for W32).
   4077    * @ingroup response
   4078    */
   4079   MHD_RESPMEM_MUST_FREE,
   4080 
   4081   /**
   4082    * Buffer is in transient memory, but not on the heap (for example,
   4083    * on the stack or non-`malloc()` allocated) and only valid during the
   4084    * call to #MHD_create_response_from_buffer.  MHD must make its
   4085    * own private copy of the data for processing.
   4086    * @ingroup response
   4087    */
   4088   MHD_RESPMEM_MUST_COPY
   4089 
   4090 } _MHD_FIXED_ENUM;
   4091 
   4092 
   4093 /**
   4094  * Create a response object with the content of provided buffer used as
   4095  * the response body.
   4096  *
   4097  * The response object can be extended with header information and then
   4098  * be used any number of times.
   4099  *
   4100  * If response object is used to answer HEAD request then the body
   4101  * of the response is not used, while all headers (including automatic
   4102  * headers) are used.
   4103  *
   4104  * @param size size of the data portion of the response
   4105  * @param buffer size bytes containing the response's data portion
   4106  * @param mode flags for buffer management
   4107  * @return NULL on error (i.e. invalid arguments, out of memory)
   4108  * @ingroup response
   4109  */
   4110 _MHD_EXTERN struct MHD_Response *
   4111 MHD_create_response_from_buffer (size_t size,
   4112                                  void *buffer,
   4113                                  enum MHD_ResponseMemoryMode mode);
   4114 
   4115 
   4116 /**
   4117  * Create a response object with the content of provided statically allocated
   4118  * buffer used as the response body.
   4119  *
   4120  * The buffer must be valid for the lifetime of the response. The easiest way
   4121  * to achieve this is to use a statically allocated buffer.
   4122  *
   4123  * The response object can be extended with header information and then
   4124  * be used any number of times.
   4125  *
   4126  * If response object is used to answer HEAD request then the body
   4127  * of the response is not used, while all headers (including automatic
   4128  * headers) are used.
   4129  *
   4130  * @param size the size of the data in @a buffer, can be zero
   4131  * @param buffer the buffer with the data for the response body, can be NULL
   4132  *               if @a size is zero
   4133  * @return NULL on error (i.e. invalid arguments, out of memory)
   4134  * @note Available since #MHD_VERSION 0x00097701
   4135  * @ingroup response
   4136  */
   4137 _MHD_EXTERN struct MHD_Response *
   4138 MHD_create_response_from_buffer_static (size_t size,
   4139                                         const void *buffer);
   4140 
   4141 
   4142 /**
   4143  * Create a response object with the content of provided temporal buffer
   4144  * used as the response body.
   4145  *
   4146  * An internal copy of the buffer will be made automatically, so buffer have
   4147  * to be valid only during the call of this function (as a typical example:
   4148  * buffer is a local (non-static) array).
   4149  *
   4150  * The response object can be extended with header information and then
   4151  * be used any number of times.
   4152  *
   4153  * If response object is used to answer HEAD request then the body
   4154  * of the response is not used, while all headers (including automatic
   4155  * headers) are used.
   4156  *
   4157  * @param size the size of the data in @a buffer, can be zero
   4158  * @param buffer the buffer with the data for the response body, can be NULL
   4159  *               if @a size is zero
   4160  * @return NULL on error (i.e. invalid arguments, out of memory)
   4161  * @note Available since #MHD_VERSION 0x00097701
   4162  * @ingroup response
   4163  */
   4164 _MHD_EXTERN struct MHD_Response *
   4165 MHD_create_response_from_buffer_copy (size_t size,
   4166                                       const void *buffer);
   4167 
   4168 
   4169 /**
   4170  * Create a response object with the content of provided buffer used as
   4171  * the response body.
   4172  *
   4173  * The response object can be extended with header information and then
   4174  * be used any number of times.
   4175  *
   4176  * If response object is used to answer HEAD request then the body
   4177  * of the response is not used, while all headers (including automatic
   4178  * headers) are used.
   4179  *
   4180  * @param size size of the data portion of the response
   4181  * @param buffer size bytes containing the response's data portion
   4182  * @param crfc function to call to free the @a buffer
   4183  * @return NULL on error (i.e. invalid arguments, out of memory)
   4184  * @note Available since #MHD_VERSION 0x00096000
   4185  * @ingroup response
   4186  */
   4187 _MHD_EXTERN struct MHD_Response *
   4188 MHD_create_response_from_buffer_with_free_callback (size_t size,
   4189                                                     void *buffer,
   4190                                                     MHD_ContentReaderFreeCallback
   4191                                                     crfc);
   4192 
   4193 
   4194 /**
   4195  * Create a response object with the content of provided buffer used as
   4196  * the response body.
   4197  *
   4198  * The response object can be extended with header information and then
   4199  * be used any number of times.
   4200  *
   4201  * If response object is used to answer HEAD request then the body
   4202  * of the response is not used, while all headers (including automatic
   4203  * headers) are used.
   4204  *
   4205  * @param size size of the data portion of the response
   4206  * @param buffer size bytes containing the response's data portion
   4207  * @param crfc function to call to cleanup, if set to NULL then callback
   4208  *             is not called
   4209  * @param crfc_cls an argument for @a crfc
   4210  * @return NULL on error (i.e. invalid arguments, out of memory)
   4211  * @note Available since #MHD_VERSION 0x00097302
   4212  * @note 'const' qualifier is used for @a buffer since #MHD_VERSION 0x00097701
   4213  * @ingroup response
   4214  */
   4215 _MHD_EXTERN struct MHD_Response *
   4216 MHD_create_response_from_buffer_with_free_callback_cls (size_t size,
   4217                                                         const void *buffer,
   4218                                                         MHD_ContentReaderFreeCallback
   4219                                                         crfc,
   4220                                                         void *crfc_cls);
   4221 
   4222 
   4223 /**
   4224  * Create a response object with the content of provided file used as
   4225  * the response body.
   4226  *
   4227  * The response object can be extended with header information and then
   4228  * be used any number of times.
   4229  *
   4230  * If response object is used to answer HEAD request then the body
   4231  * of the response is not used, while all headers (including automatic
   4232  * headers) are used.
   4233  *
   4234  * @param size size of the data portion of the response
   4235  * @param fd file descriptor referring to a file on disk with the
   4236  *        data; will be closed when response is destroyed;
   4237  *        fd should be in 'blocking' mode
   4238  * @return NULL on error (i.e. invalid arguments, out of memory)
   4239  * @ingroup response
   4240  */
   4241 _MHD_EXTERN struct MHD_Response *
   4242 MHD_create_response_from_fd (size_t size,
   4243                              int fd);
   4244 
   4245 
   4246 /**
   4247  * Create a response object with the response body created by reading
   4248  * the provided pipe.
   4249  *
   4250  * The response object can be extended with header information and
   4251  * then be used ONLY ONCE.
   4252  *
   4253  * If response object is used to answer HEAD request then the body
   4254  * of the response is not used, while all headers (including automatic
   4255  * headers) are used.
   4256  *
   4257  * @param fd file descriptor referring to a read-end of a pipe with the
   4258  *        data; will be closed when response is destroyed;
   4259  *        fd should be in 'blocking' mode
   4260  * @return NULL on error (i.e. invalid arguments, out of memory)
   4261  * @note Available since #MHD_VERSION 0x00097102
   4262  * @ingroup response
   4263  */
   4264 _MHD_EXTERN struct MHD_Response *
   4265 MHD_create_response_from_pipe (int fd);
   4266 
   4267 
   4268 /**
   4269  * Create a response object with the content of provided file used as
   4270  * the response body.
   4271  *
   4272  * The response object can be extended with header information and then
   4273  * be used any number of times.
   4274  *
   4275  * If response object is used to answer HEAD request then the body
   4276  * of the response is not used, while all headers (including automatic
   4277  * headers) are used.
   4278  *
   4279  * @param size size of the data portion of the response;
   4280  *        sizes larger than 2 GiB may be not supported by OS or
   4281  *        MHD build; see ::MHD_FEATURE_LARGE_FILE
   4282  * @param fd file descriptor referring to a file on disk with the
   4283  *        data; will be closed when response is destroyed;
   4284  *        fd should be in 'blocking' mode
   4285  * @return NULL on error (i.e. invalid arguments, out of memory)
   4286  * @ingroup response
   4287  */
   4288 _MHD_EXTERN struct MHD_Response *
   4289 MHD_create_response_from_fd64 (uint64_t size,
   4290                                int fd);
   4291 
   4292 
   4293 /**
   4294  * Create a response object with the content of provided file with
   4295  * specified offset used as the response body.
   4296  *
   4297  * The response object can be extended with header information and then
   4298  * be used any number of times.
   4299  *
   4300  * If response object is used to answer HEAD request then the body
   4301  * of the response is not used, while all headers (including automatic
   4302  * headers) are used.
   4303  *
   4304  * @param size size of the data portion of the response
   4305  * @param fd file descriptor referring to a file on disk with the
   4306  *        data; will be closed when response is destroyed;
   4307  *        fd should be in 'blocking' mode
   4308  * @param offset offset to start reading from in the file;
   4309  *        Be careful! `off_t` may have been compiled to be a
   4310  *        64-bit variable for MHD, in which case your application
   4311  *        also has to be compiled using the same options! Read
   4312  *        the MHD manual for more details.
   4313  * @return NULL on error (i.e. invalid arguments, out of memory)
   4314  * @ingroup response
   4315  */
   4316 _MHD_DEPR_FUNC ( \
   4317   "Function MHD_create_response_from_fd_at_offset() is deprecated, use MHD_create_response_from_fd_at_offset64()" \
   4318   ) \
   4319   _MHD_EXTERN struct MHD_Response *
   4320 MHD_create_response_from_fd_at_offset (size_t size,
   4321                                        int fd,
   4322                                        off_t offset);
   4323 
   4324 #if ! defined(_MHD_NO_DEPR_IN_MACRO) || defined(_MHD_NO_DEPR_FUNC)
   4325 /* Substitute MHD_create_response_from_fd_at_offset64() instead of MHD_create_response_from_fd_at_offset()
   4326    to minimize potential problems with different off_t sizes */
   4327 #define MHD_create_response_from_fd_at_offset(size,fd,offset) \
   4328         _MHD_DEPR_IN_MACRO ( \
   4329           "Usage of MHD_create_response_from_fd_at_offset() is deprecated, use MHD_create_response_from_fd_at_offset64()") \
   4330         MHD_create_response_from_fd_at_offset64 ((size),(fd),(offset))
   4331 #endif /* !_MHD_NO_DEPR_IN_MACRO || _MHD_NO_DEPR_FUNC */
   4332 
   4333 
   4334 /**
   4335  * Create a response object with the content of provided file with
   4336  * specified offset used as the response body.
   4337  *
   4338  * The response object can be extended with header information and then
   4339  * be used any number of times.
   4340  *
   4341  * If response object is used to answer HEAD request then the body
   4342  * of the response is not used, while all headers (including automatic
   4343  * headers) are used.
   4344  *
   4345  * @param size size of the data portion of the response;
   4346  *        sizes larger than 2 GiB may be not supported by OS or
   4347  *        MHD build; see ::MHD_FEATURE_LARGE_FILE
   4348  * @param fd file descriptor referring to a file on disk with the
   4349  *        data; will be closed when response is destroyed;
   4350  *        fd should be in 'blocking' mode
   4351  * @param offset offset to start reading from in the file;
   4352  *        reading file beyond 2 GiB may be not supported by OS or
   4353  *        MHD build; see ::MHD_FEATURE_LARGE_FILE
   4354  * @return NULL on error (i.e. invalid arguments, out of memory)
   4355  * @ingroup response
   4356  */
   4357 _MHD_EXTERN struct MHD_Response *
   4358 MHD_create_response_from_fd_at_offset64 (uint64_t size,
   4359                                          int fd,
   4360                                          uint64_t offset);
   4361 
   4362 
   4363 /**
   4364  * Create a response object with an array of memory buffers
   4365  * used as the response body.
   4366  *
   4367  * The response object can be extended with header information and then
   4368  * be used any number of times.
   4369  *
   4370  * If response object is used to answer HEAD request then the body
   4371  * of the response is not used, while all headers (including automatic
   4372  * headers) are used.
   4373  *
   4374  * @param iov the array for response data buffers, an internal copy of this
   4375  *        will be made
   4376  * @param iovcnt the number of elements in @a iov
   4377  * @param free_cb the callback to clean up any data associated with @a iov when
   4378  *        the response is destroyed.
   4379  * @param cls the argument passed to @a free_cb
   4380  * @return NULL on error (i.e. invalid arguments, out of memory)
   4381  * @note Available since #MHD_VERSION 0x00097204
   4382  * @ingroup response
   4383  */
   4384 _MHD_EXTERN struct MHD_Response *
   4385 MHD_create_response_from_iovec (const struct MHD_IoVec *iov,
   4386                                 unsigned int iovcnt,
   4387                                 MHD_ContentReaderFreeCallback free_cb,
   4388                                 void *cls);
   4389 
   4390 
   4391 /**
   4392  * Create a response object with empty (zero size) body.
   4393  *
   4394  * The response object can be extended with header information and then be used
   4395  * any number of times.
   4396  *
   4397  * This function is a faster equivalent of #MHD_create_response_from_buffer call
   4398  * with zero size combined with call of #MHD_set_response_options.
   4399  *
   4400  * @param flags the flags for the new response object
   4401  * @return NULL on error (i.e. invalid arguments, out of memory),
   4402  *         the pointer to the created response object otherwise
   4403  * @note Available since #MHD_VERSION 0x00097701
   4404  * @ingroup response
   4405  */
   4406 _MHD_EXTERN struct MHD_Response *
   4407 MHD_create_response_empty (enum MHD_ResponseFlags flags);
   4408 
   4409 
   4410 /**
   4411  * Enumeration for actions MHD should perform on the underlying socket
   4412  * of the upgrade.  This API is not finalized, and in particular
   4413  * the final set of actions is yet to be decided. This is just an
   4414  * idea for what we might want.
   4415  */
   4416 enum MHD_UpgradeAction
   4417 {
   4418 
   4419   /**
   4420    * Close the socket, the application is done with it.
   4421    *
   4422    * Takes no extra arguments.
   4423    */
   4424   MHD_UPGRADE_ACTION_CLOSE = 0,
   4425 
   4426   /**
   4427    * Enable CORKing on the underlying socket.
   4428    */
   4429   MHD_UPGRADE_ACTION_CORK_ON = 1,
   4430 
   4431   /**
   4432    * Disable CORKing on the underlying socket.
   4433    */
   4434   MHD_UPGRADE_ACTION_CORK_OFF = 2
   4435 
   4436 } _MHD_FIXED_ENUM;
   4437 
   4438 
   4439 /**
   4440  * Handle given to the application to manage special
   4441  * actions relating to MHD responses that "upgrade"
   4442  * the HTTP protocol (i.e. to WebSockets).
   4443  */
   4444 struct MHD_UpgradeResponseHandle;
   4445 
   4446 
   4447 /**
   4448  * This connection-specific callback is provided by MHD to
   4449  * applications (unusual) during the #MHD_UpgradeHandler.
   4450  * It allows applications to perform 'special' actions on
   4451  * the underlying socket from the upgrade.
   4452  *
   4453  * @param urh the handle identifying the connection to perform
   4454  *            the upgrade @a action on.
   4455  * @param action which action should be performed
   4456  * @param ... arguments to the action (depends on the action)
   4457  * @return #MHD_NO on error, #MHD_YES on success
   4458  */
   4459 _MHD_EXTERN enum MHD_Result
   4460 MHD_upgrade_action (struct MHD_UpgradeResponseHandle *urh,
   4461                     enum MHD_UpgradeAction action,
   4462                     ...);
   4463 
   4464 
   4465 /**
   4466  * Function called after a protocol "upgrade" response was sent
   4467  * successfully and the socket should now be controlled by some
   4468  * protocol other than HTTP.
   4469  *
   4470  * Any data already received on the socket will be made available in
   4471  * @e extra_in.  This can happen if the application sent extra data
   4472  * before MHD send the upgrade response.  The application should
   4473  * treat data from @a extra_in as if it had read it from the socket.
   4474  *
   4475  * Note that the application must not close() @a sock directly,
   4476  * but instead use #MHD_upgrade_action() for special operations
   4477  * on @a sock.
   4478  *
   4479  * Data forwarding to "upgraded" @a sock will be started as soon
   4480  * as this function return.
   4481  *
   4482  * Except when in 'thread-per-connection' mode, implementations
   4483  * of this function should never block (as it will still be called
   4484  * from within the main event loop).
   4485  *
   4486  * @param cls closure, whatever was given to #MHD_create_response_for_upgrade().
   4487  * @param connection original HTTP connection handle,
   4488  *                   giving the function a last chance
   4489  *                   to inspect the original HTTP request
   4490  * @param req_cls last value left in `req_cls` of the `MHD_AccessHandlerCallback`
   4491  * @param extra_in if we happened to have read bytes after the
   4492  *                 HTTP header already (because the client sent
   4493  *                 more than the HTTP header of the request before
   4494  *                 we sent the upgrade response),
   4495  *                 these are the extra bytes already read from @a sock
   4496  *                 by MHD.  The application should treat these as if
   4497  *                 it had read them from @a sock.
   4498  * @param extra_in_size number of bytes in @a extra_in
   4499  * @param sock socket to use for bi-directional communication
   4500  *        with the client.  For HTTPS, this may not be a socket
   4501  *        that is directly connected to the client and thus certain
   4502  *        operations (TCP-specific setsockopt(), getsockopt(), etc.)
   4503  *        may not work as expected (as the socket could be from a
   4504  *        socketpair() or a TCP-loopback).  The application is expected
   4505  *        to perform read()/recv() and write()/send() calls on the socket.
   4506  *        The application may also call shutdown(), but must not call
   4507  *        close() directly.
   4508  * @param urh argument for #MHD_upgrade_action()s on this @a connection.
   4509  *        Applications must eventually use this callback to (indirectly)
   4510  *        perform the close() action on the @a sock.
   4511  */
   4512 typedef void
   4513 (*MHD_UpgradeHandler)(void *cls,
   4514                       struct MHD_Connection *connection,
   4515                       void *req_cls,
   4516                       const char *extra_in,
   4517                       size_t extra_in_size,
   4518                       MHD_socket sock,
   4519                       struct MHD_UpgradeResponseHandle *urh);
   4520 
   4521 
   4522 /**
   4523  * Create a response object that can be used for 101 UPGRADE
   4524  * responses, for example to implement WebSockets.  After sending the
   4525  * response, control over the data stream is given to the callback (which
   4526  * can then, for example, start some bi-directional communication).
   4527  * If the response is queued for multiple connections, the callback
   4528  * will be called for each connection.  The callback
   4529  * will ONLY be called after the response header was successfully passed
   4530  * to the OS; if there are communication errors before, the usual MHD
   4531  * connection error handling code will be performed.
   4532  *
   4533  * Setting the correct HTTP code (i.e. MHD_HTTP_SWITCHING_PROTOCOLS)
   4534  * and setting correct HTTP headers for the upgrade must be done
   4535  * manually (this way, it is possible to implement most existing
   4536  * WebSocket versions using this API; in fact, this API might be useful
   4537  * for any protocol switch, not just WebSockets).  Note that
   4538  * draft-ietf-hybi-thewebsocketprotocol-00 cannot be implemented this
   4539  * way as the header "HTTP/1.1 101 WebSocket Protocol Handshake"
   4540  * cannot be generated; instead, MHD will always produce "HTTP/1.1 101
   4541  * Switching Protocols" (if the response code 101 is used).
   4542  *
   4543  * As usual, the response object can be extended with header
   4544  * information and then be used any number of times (as long as the
   4545  * header information is not connection-specific).
   4546  *
   4547  * @param upgrade_handler function to call with the "upgraded" socket
   4548  * @param upgrade_handler_cls closure for @a upgrade_handler
   4549  * @return NULL on error (i.e. invalid arguments, out of memory)
   4550  */
   4551 _MHD_EXTERN struct MHD_Response *
   4552 MHD_create_response_for_upgrade (MHD_UpgradeHandler upgrade_handler,
   4553                                  void *upgrade_handler_cls);
   4554 
   4555 
   4556 /**
   4557  * Destroy a response object and associated resources.  Note that
   4558  * libmicrohttpd may keep some of the resources around if the response
   4559  * is still in the queue for some clients, so the memory may not
   4560  * necessarily be freed immediately.
   4561  *
   4562  * @param response response to destroy
   4563  * @ingroup response
   4564  */
   4565 _MHD_EXTERN void
   4566 MHD_destroy_response (struct MHD_Response *response);
   4567 
   4568 
   4569 /**
   4570  * Add a header line to the response.
   4571  *
   4572  * When reply is generated with queued response, some headers are generated
   4573  * automatically. Automatically generated headers are only sent to the client,
   4574  * but not added back to the response object.
   4575  *
   4576  * The list of automatic headers:
   4577  * + "Date" header is added automatically unless already set by
   4578  *   this function
   4579  *   @see #MHD_USE_SUPPRESS_DATE_NO_CLOCK
   4580  * + "Content-Length" is added automatically when required, attempt to set
   4581  *   it manually by this function is ignored.
   4582  *   @see #MHD_RF_INSANITY_HEADER_CONTENT_LENGTH
   4583  * + "Transfer-Encoding" with value "chunked" is added automatically,
   4584  *   when chunked transfer encoding is used automatically. Same header with
   4585  *   the same value can be set manually by this function to enforce chunked
   4586  *   encoding, however for HTTP/1.0 clients chunked encoding will not be used
   4587  *   and manually set "Transfer-Encoding" header is automatically removed
   4588  *   for HTTP/1.0 clients
   4589  * + "Connection" may be added automatically with value "Keep-Alive" (only
   4590  *   for HTTP/1.0 clients) or "Close". The header "Connection" with value
   4591  *   "Close" could be set by this function to enforce closure of
   4592  *   the connection after sending this response. "Keep-Alive" cannot be
   4593  *   enforced and will be removed automatically.
   4594  *   @see #MHD_RF_SEND_KEEP_ALIVE_HEADER
   4595  *
   4596  * Some headers are pre-processed by this function:
   4597  * * "Connection" headers are combined into single header entry, value is
   4598  *   normilised, "Keep-Alive" tokens are removed.
   4599  * * "Transfer-Encoding" header: the only one header is allowed, the only
   4600  *   allowed value is "chunked".
   4601  * * "Date" header: the only one header is allowed, the second added header
   4602  *   replaces the first one.
   4603  * * "Content-Length" application-defined header is not allowed.
   4604  *   @see #MHD_RF_INSANITY_HEADER_CONTENT_LENGTH
   4605  *
   4606  * Headers are used in order as they were added.
   4607  *
   4608  * @param response the response to add a header to
   4609  * @param header the header name to add, no need to be static, an internal copy
   4610  *               will be created automatically
   4611  * @param content the header value to add, no need to be static, an internal
   4612  *                copy will be created automatically
   4613  * @return #MHD_YES on success,
   4614  *         #MHD_NO on error (i.e. invalid header or content format),
   4615  *         or out of memory
   4616  * @ingroup response
   4617  */
   4618 _MHD_EXTERN enum MHD_Result
   4619 MHD_add_response_header (struct MHD_Response *response,
   4620                          const char *header,
   4621                          const char *content);
   4622 
   4623 
   4624 /**
   4625  * Add a footer line to the response.
   4626  *
   4627  * @param response response to remove a header from
   4628  * @param footer the footer to delete
   4629  * @param content value to delete
   4630  * @return #MHD_NO on error (i.e. invalid footer or content format).
   4631  * @ingroup response
   4632  */
   4633 _MHD_EXTERN enum MHD_Result
   4634 MHD_add_response_footer (struct MHD_Response *response,
   4635                          const char *footer,
   4636                          const char *content);
   4637 
   4638 
   4639 /**
   4640  * Delete a header (or footer) line from the response.
   4641  *
   4642  * For "Connection" headers this function remove all tokens from existing
   4643  * value. Successful result means that at least one token has been removed.
   4644  * If all tokens are removed from "Connection" header, the empty "Connection"
   4645  * header removed.
   4646  *
   4647  * @param response response to remove a header from
   4648  * @param header the header to delete
   4649  * @param content value to delete
   4650  * @return #MHD_NO on error (no such header known)
   4651  * @ingroup response
   4652  */
   4653 _MHD_EXTERN enum MHD_Result
   4654 MHD_del_response_header (struct MHD_Response *response,
   4655                          const char *header,
   4656                          const char *content);
   4657 
   4658 
   4659 /**
   4660  * Get all of the headers (and footers) added to a response.
   4661  *
   4662  * @param response response to query
   4663  * @param iterator callback to call on each header;
   4664  *        may be NULL (then just count headers)
   4665  * @param iterator_cls extra argument to @a iterator
   4666  * @return number of entries iterated over
   4667  * @ingroup response
   4668  */
   4669 _MHD_EXTERN int
   4670 MHD_get_response_headers (struct MHD_Response *response,
   4671                           MHD_KeyValueIterator iterator,
   4672                           void *iterator_cls);
   4673 
   4674 
   4675 /**
   4676  * Get a particular header (or footer) from the response.
   4677  *
   4678  * @param response response to query
   4679  * @param key which header to get
   4680  * @return NULL if header does not exist
   4681  * @ingroup response
   4682  */
   4683 _MHD_EXTERN const char *
   4684 MHD_get_response_header (struct MHD_Response *response,
   4685                          const char *key);
   4686 
   4687 
   4688 /* ********************** PostProcessor functions ********************** */
   4689 
   4690 /**
   4691  * Create a `struct MHD_PostProcessor`.
   4692  *
   4693  * A `struct MHD_PostProcessor` can be used to (incrementally) parse
   4694  * the data portion of a POST request.  Note that some buggy browsers
   4695  * fail to set the encoding type.  If you want to support those, you
   4696  * may have to call #MHD_set_connection_value with the proper encoding
   4697  * type before creating a post processor (if no supported encoding
   4698  * type is set, this function will fail).
   4699  *
   4700  * @param connection the connection on which the POST is
   4701  *        happening (used to determine the POST format)
   4702  * @param buffer_size maximum number of bytes to use for
   4703  *        internal buffering (used only for the parsing,
   4704  *        specifically the parsing of the keys).  A
   4705  *        tiny value (256-1024) should be sufficient.
   4706  *        Do NOT use a value smaller than 256.  For good
   4707  *        performance, use 32 or 64k (i.e. 65536).
   4708  * @param iter iterator to be called with the parsed data,
   4709  *        Must NOT be NULL.
   4710  * @param iter_cls first argument to @a iter
   4711  * @return NULL on error (out of memory, unsupported encoding),
   4712  *         otherwise a PP handle
   4713  * @ingroup request
   4714  */
   4715 _MHD_EXTERN struct MHD_PostProcessor *
   4716 MHD_create_post_processor (struct MHD_Connection *connection,
   4717                            size_t buffer_size,
   4718                            MHD_PostDataIterator iter, void *iter_cls);
   4719 
   4720 
   4721 /**
   4722  * Parse and process POST data.  Call this function when POST data is
   4723  * available (usually during an #MHD_AccessHandlerCallback) with the
   4724  * "upload_data" and "upload_data_size".  Whenever possible, this will
   4725  * then cause calls to the #MHD_PostDataIterator.
   4726  *
   4727  * @param pp the post processor
   4728  * @param post_data @a post_data_len bytes of POST data
   4729  * @param post_data_len length of @a post_data
   4730  * @return #MHD_YES on success, #MHD_NO on error
   4731  *         (out-of-memory, iterator aborted, parse error)
   4732  * @ingroup request
   4733  */
   4734 _MHD_EXTERN enum MHD_Result
   4735 MHD_post_process (struct MHD_PostProcessor *pp,
   4736                   const char *post_data,
   4737                   size_t post_data_len);
   4738 
   4739 
   4740 /**
   4741  * Release PostProcessor resources.
   4742  *
   4743  * @param pp the PostProcessor to destroy
   4744  * @return #MHD_YES if processing completed nicely,
   4745  *         #MHD_NO if there were spurious characters / formatting
   4746  *                problems; it is common to ignore the return
   4747  *                value of this function
   4748  * @ingroup request
   4749  */
   4750 _MHD_EXTERN enum MHD_Result
   4751 MHD_destroy_post_processor (struct MHD_PostProcessor *pp);
   4752 
   4753 
   4754 /* ********************* Digest Authentication functions *************** */
   4755 
   4756 
   4757 /**
   4758  * Length of the binary output of the MD5 hash function.
   4759  * @sa #MHD_digest_get_hash_size()
   4760  * @ingroup authentication
   4761  */
   4762 #define MHD_MD5_DIGEST_SIZE 16
   4763 
   4764 /**
   4765  * Length of the binary output of the SHA-256 hash function.
   4766  * @sa #MHD_digest_get_hash_size()
   4767  * @ingroup authentication
   4768  */
   4769 #define MHD_SHA256_DIGEST_SIZE 32
   4770 
   4771 /**
   4772  * Length of the binary output of the SHA-512/256 hash function.
   4773  * @warning While this value is the same as the #MHD_SHA256_DIGEST_SIZE,
   4774  *          the calculated digests for SHA-256 and SHA-512/256 are different.
   4775  * @sa #MHD_digest_get_hash_size()
   4776  * @note Available since #MHD_VERSION 0x00097701
   4777  * @ingroup authentication
   4778  */
   4779 #define MHD_SHA512_256_DIGEST_SIZE 32
   4780 
   4781 /**
   4782  * Base type of hash calculation.
   4783  * Used as part of #MHD_DigestAuthAlgo3 values.
   4784  *
   4785  * @warning Not used directly by MHD API.
   4786  * @note Available since #MHD_VERSION 0x00097701
   4787  */
   4788 enum MHD_DigestBaseAlgo
   4789 {
   4790   /**
   4791    * Invalid hash algorithm value
   4792    */
   4793   MHD_DIGEST_BASE_ALGO_INVALID = 0,
   4794 
   4795   /**
   4796    * MD5 hash algorithm.
   4797    * As specified by RFC1321
   4798    */
   4799   MHD_DIGEST_BASE_ALGO_MD5 = (1 << 0),
   4800 
   4801   /**
   4802    * SHA-256 hash algorithm.
   4803    * As specified by FIPS PUB 180-4
   4804    */
   4805   MHD_DIGEST_BASE_ALGO_SHA256 = (1 << 1),
   4806 
   4807   /**
   4808    * SHA-512/256 hash algorithm.
   4809    * As specified by FIPS PUB 180-4
   4810    */
   4811   MHD_DIGEST_BASE_ALGO_SHA512_256 = (1 << 2)
   4812 } _MHD_FIXED_FLAGS_ENUM;
   4813 
   4814 /**
   4815  * The flag indicating non-session algorithm types,
   4816  * like 'MD5', 'SHA-256' or 'SHA-512-256'.
   4817  * @note Available since #MHD_VERSION 0x00097701
   4818  */
   4819 #define MHD_DIGEST_AUTH_ALGO3_NON_SESSION    (1 << 6)
   4820 
   4821 /**
   4822  * The flag indicating session algorithm types,
   4823  * like 'MD5-sess', 'SHA-256-sess' or 'SHA-512-256-sess'.
   4824  * @note Available since #MHD_VERSION 0x00097701
   4825  */
   4826 #define MHD_DIGEST_AUTH_ALGO3_SESSION        (1 << 7)
   4827 
   4828 /**
   4829  * Digest algorithm identification
   4830  * @warning Do not be confused with #MHD_DigestAuthAlgorithm,
   4831  *          which uses other values!
   4832  * @note Available since #MHD_VERSION 0x00097701
   4833  */
   4834 enum MHD_DigestAuthAlgo3
   4835 {
   4836   /**
   4837    * Unknown or wrong algorithm type.
   4838    * Used in struct MHD_DigestAuthInfo to indicate client value that
   4839    * cannot by identified.
   4840    */
   4841   MHD_DIGEST_AUTH_ALGO3_INVALID = 0,
   4842 
   4843   /**
   4844    * The 'MD5' algorithm, non-session version.
   4845    */
   4846   MHD_DIGEST_AUTH_ALGO3_MD5 =
   4847     MHD_DIGEST_BASE_ALGO_MD5 | MHD_DIGEST_AUTH_ALGO3_NON_SESSION,
   4848 
   4849   /**
   4850    * The 'MD5-sess' algorithm.
   4851    * Not supported by MHD for authentication.
   4852    */
   4853   MHD_DIGEST_AUTH_ALGO3_MD5_SESSION =
   4854     MHD_DIGEST_BASE_ALGO_MD5 | MHD_DIGEST_AUTH_ALGO3_SESSION,
   4855 
   4856   /**
   4857    * The 'SHA-256' algorithm, non-session version.
   4858    */
   4859   MHD_DIGEST_AUTH_ALGO3_SHA256 =
   4860     MHD_DIGEST_BASE_ALGO_SHA256 | MHD_DIGEST_AUTH_ALGO3_NON_SESSION,
   4861 
   4862   /**
   4863    * The 'SHA-256-sess' algorithm.
   4864    * Not supported by MHD for authentication.
   4865    */
   4866   MHD_DIGEST_AUTH_ALGO3_SHA256_SESSION =
   4867     MHD_DIGEST_BASE_ALGO_SHA256 | MHD_DIGEST_AUTH_ALGO3_SESSION,
   4868 
   4869   /**
   4870    * The 'SHA-512-256' (SHA-512/256) algorithm.
   4871    */
   4872   MHD_DIGEST_AUTH_ALGO3_SHA512_256 =
   4873     MHD_DIGEST_BASE_ALGO_SHA512_256 | MHD_DIGEST_AUTH_ALGO3_NON_SESSION,
   4874 
   4875   /**
   4876    * The 'SHA-512-256-sess' (SHA-512/256 session) algorithm.
   4877    * Not supported by MHD for authentication.
   4878    */
   4879   MHD_DIGEST_AUTH_ALGO3_SHA512_256_SESSION =
   4880     MHD_DIGEST_BASE_ALGO_SHA512_256 | MHD_DIGEST_AUTH_ALGO3_SESSION
   4881 };
   4882 
   4883 
   4884 /**
   4885  * Get digest size for specified algorithm.
   4886  *
   4887  * The size of the digest specifies the size of the userhash, userdigest
   4888  * and other parameters which size depends on used hash algorithm.
   4889  * @param algo3 the algorithm to check
   4890  * @return the size of the digest (either #MHD_MD5_DIGEST_SIZE or
   4891  *         #MHD_SHA256_DIGEST_SIZE/MHD_SHA512_256_DIGEST_SIZE)
   4892  *         or zero if the input value is not supported or not valid
   4893  * @sa #MHD_digest_auth_calc_userdigest()
   4894  * @sa #MHD_digest_auth_calc_userhash(), #MHD_digest_auth_calc_userhash_hex()
   4895  * @note Available since #MHD_VERSION 0x00097701
   4896  * @ingroup authentication
   4897  */
   4898 _MHD_EXTERN size_t
   4899 MHD_digest_get_hash_size (enum MHD_DigestAuthAlgo3 algo3);
   4900 
   4901 /**
   4902  * Digest algorithm identification, allow multiple selection.
   4903  *
   4904  * #MHD_DigestAuthAlgo3 always can be casted to #MHD_DigestAuthMultiAlgo3, but
   4905  * not vice versa.
   4906  *
   4907  * @note Available since #MHD_VERSION 0x00097701
   4908  */
   4909 enum MHD_DigestAuthMultiAlgo3
   4910 {
   4911   /**
   4912    * Unknown or wrong algorithm type.
   4913    */
   4914   MHD_DIGEST_AUTH_MULT_ALGO3_INVALID = MHD_DIGEST_AUTH_ALGO3_INVALID,
   4915 
   4916   /**
   4917    * The 'MD5' algorithm, non-session version.
   4918    */
   4919   MHD_DIGEST_AUTH_MULT_ALGO3_MD5 = MHD_DIGEST_AUTH_ALGO3_MD5,
   4920 
   4921   /**
   4922    * The 'MD5-sess' algorithm.
   4923    * Not supported by MHD for authentication.
   4924    * Reserved value.
   4925    */
   4926   MHD_DIGEST_AUTH_MULT_ALGO3_MD5_SESSION = MHD_DIGEST_AUTH_ALGO3_MD5_SESSION,
   4927 
   4928   /**
   4929    * The 'SHA-256' algorithm, non-session version.
   4930    */
   4931   MHD_DIGEST_AUTH_MULT_ALGO3_SHA256 = MHD_DIGEST_AUTH_ALGO3_SHA256,
   4932 
   4933   /**
   4934    * The 'SHA-256-sess' algorithm.
   4935    * Not supported by MHD for authentication.
   4936    * Reserved value.
   4937    */
   4938   MHD_DIGEST_AUTH_MULT_ALGO3_SHA256_SESSION =
   4939     MHD_DIGEST_AUTH_ALGO3_SHA256_SESSION,
   4940 
   4941   /**
   4942    * The 'SHA-512-256' (SHA-512/256) algorithm, non-session version.
   4943    */
   4944   MHD_DIGEST_AUTH_MULT_ALGO3_SHA512_256 = MHD_DIGEST_AUTH_ALGO3_SHA512_256,
   4945 
   4946   /**
   4947    * The 'SHA-512-256-sess' (SHA-512/256 session) algorithm.
   4948    * Not supported by MHD for authentication.
   4949    * Reserved value.
   4950    */
   4951   MHD_DIGEST_AUTH_MULT_ALGO3_SHA512_256_SESSION =
   4952     MHD_DIGEST_AUTH_ALGO3_SHA512_256_SESSION,
   4953 
   4954   /**
   4955    * SHA-256 or SHA-512/256 non-session algorithm, MHD will choose
   4956    * the preferred or the matching one.
   4957    */
   4958   MHD_DIGEST_AUTH_MULT_ALGO3_SHA_ANY_NON_SESSION =
   4959     MHD_DIGEST_AUTH_ALGO3_SHA256 | MHD_DIGEST_AUTH_ALGO3_SHA512_256,
   4960 
   4961   /**
   4962    * Any non-session algorithm, MHD will choose the preferred or
   4963    * the matching one.
   4964    */
   4965   MHD_DIGEST_AUTH_MULT_ALGO3_ANY_NON_SESSION =
   4966     (0x3F) | MHD_DIGEST_AUTH_ALGO3_NON_SESSION,
   4967 
   4968   /**
   4969    * The SHA-256 or SHA-512/256 session algorithm.
   4970    * Not supported by MHD.
   4971    * Reserved value.
   4972    */
   4973   MHD_DIGEST_AUTH_MULT_ALGO3_SHA_ANY_SESSION =
   4974     MHD_DIGEST_AUTH_ALGO3_SHA256_SESSION
   4975     | MHD_DIGEST_AUTH_ALGO3_SHA512_256_SESSION,
   4976 
   4977   /**
   4978    * Any session algorithm.
   4979    * Not supported by MHD.
   4980    * Reserved value.
   4981    */
   4982   MHD_DIGEST_AUTH_MULT_ALGO3_ANY_SESSION =
   4983     (0x3F) | MHD_DIGEST_AUTH_ALGO3_SESSION,
   4984 
   4985   /**
   4986    * The MD5 algorithm, session or non-session.
   4987    * Currently supported as non-session only.
   4988    */
   4989   MHD_DIGEST_AUTH_MULT_ALGO3_MD5_ANY =
   4990     MHD_DIGEST_AUTH_MULT_ALGO3_MD5 | MHD_DIGEST_AUTH_MULT_ALGO3_MD5_SESSION,
   4991 
   4992   /**
   4993    * The SHA-256 algorithm, session or non-session.
   4994    * Currently supported as non-session only.
   4995    */
   4996   MHD_DIGEST_AUTH_MULT_ALGO3_SHA256_ANY =
   4997     MHD_DIGEST_AUTH_MULT_ALGO3_SHA256
   4998     | MHD_DIGEST_AUTH_MULT_ALGO3_SHA256_SESSION,
   4999 
   5000   /**
   5001    * The SHA-512/256 algorithm, session or non-session.
   5002    * Currently supported as non-session only.
   5003    */
   5004   MHD_DIGEST_AUTH_MULT_ALGO3_SHA512_256_ANY =
   5005     MHD_DIGEST_AUTH_MULT_ALGO3_SHA512_256
   5006     | MHD_DIGEST_AUTH_MULT_ALGO3_SHA512_256_SESSION,
   5007 
   5008   /**
   5009    * The SHA-256 or SHA-512/256 algorithm, session or non-session.
   5010    * Currently supported as non-session only.
   5011    */
   5012   MHD_DIGEST_AUTH_MULT_ALGO3_SHA_ANY_ANY =
   5013     MHD_DIGEST_AUTH_MULT_ALGO3_SHA_ANY_NON_SESSION
   5014     | MHD_DIGEST_AUTH_MULT_ALGO3_SHA_ANY_SESSION,
   5015 
   5016   /**
   5017    * Any algorithm, MHD will choose the preferred or the matching one.
   5018    */
   5019   MHD_DIGEST_AUTH_MULT_ALGO3_ANY =
   5020     (0x3F) | MHD_DIGEST_AUTH_ALGO3_NON_SESSION | MHD_DIGEST_AUTH_ALGO3_SESSION
   5021 };
   5022 
   5023 
   5024 /**
   5025  * Calculate "userhash", return it as binary data.
   5026  *
   5027  * The "userhash" is the hash of the string "username:realm".
   5028  *
   5029  * The "userhash" could be used to avoid sending username in cleartext in Digest
   5030  * Authorization client's header.
   5031  *
   5032  * Userhash is not designed to hide the username in local database or files,
   5033  * as username in cleartext is required for #MHD_digest_auth_check3() function
   5034  * to check the response, but it can be used to hide username in HTTP headers.
   5035  *
   5036  * This function could be used when the new username is added to the username
   5037  * database to save the "userhash" alongside with the username (preferably) or
   5038  * when loading list of the usernames to generate the userhash for every loaded
   5039  * username (this will cause delays at the start with the long lists).
   5040  *
   5041  * Once "userhash" is generated it could be used to identify users by clients
   5042  * with "userhash" support.
   5043  * Avoid repetitive usage of this function for the same username/realm
   5044  * combination as it will cause excessive CPU load; save and re-use the result
   5045  * instead.
   5046  *
   5047  * @param algo3 the algorithm for userhash calculations
   5048  * @param username the username
   5049  * @param realm the realm
   5050  * @param[out] userhash_bin the output buffer for userhash as binary data;
   5051  *                          if this function succeeds, then this buffer has
   5052  *                          #MHD_digest_get_hash_size(algo3) bytes of userhash
   5053  *                          upon return
   5054  * @param bin_buf_size the size of the @a userhash_bin buffer, must be
   5055  *                     at least #MHD_digest_get_hash_size(algo3) bytes long
   5056  * @return MHD_YES on success,
   5057  *         MHD_NO if @a bin_buf_size is too small or if @a algo3 algorithm is
   5058  *         not supported (or external error has occurred,
   5059  *         see #MHD_FEATURE_EXTERN_HASH)
   5060  * @sa #MHD_digest_auth_calc_userhash_hex()
   5061  * @note Available since #MHD_VERSION 0x00097701
   5062  * @ingroup authentication
   5063  */
   5064 _MHD_EXTERN enum MHD_Result
   5065 MHD_digest_auth_calc_userhash (enum MHD_DigestAuthAlgo3 algo3,
   5066                                const char *username,
   5067                                const char *realm,
   5068                                void *userhash_bin,
   5069                                size_t bin_buf_size);
   5070 
   5071 
   5072 /**
   5073  * Calculate "userhash", return it as hexadecimal string.
   5074  *
   5075  * The "userhash" is the hash of the string "username:realm".
   5076  *
   5077  * The "userhash" could be used to avoid sending username in cleartext in Digest
   5078  * Authorization client's header.
   5079  *
   5080  * Userhash is not designed to hide the username in local database or files,
   5081  * as username in cleartext is required for #MHD_digest_auth_check3() function
   5082  * to check the response, but it can be used to hide username in HTTP headers.
   5083  *
   5084  * This function could be used when the new username is added to the username
   5085  * database to save the "userhash" alongside with the username (preferably) or
   5086  * when loading list of the usernames to generate the userhash for every loaded
   5087  * username (this will cause delays at the start with the long lists).
   5088  *
   5089  * Once "userhash" is generated it could be used to identify users by clients
   5090  * with "userhash" support.
   5091  * Avoid repetitive usage of this function for the same username/realm
   5092  * combination as it will cause excessive CPU load; save and re-use the result
   5093  * instead.
   5094  *
   5095  * @param algo3 the algorithm for userhash calculations
   5096  * @param username the username
   5097  * @param realm the realm
   5098  * @param[out] userhash_hex the output buffer for userhash as hex string;
   5099  *                          if this function succeeds, then this buffer has
   5100  *                          #MHD_digest_get_hash_size(algo3)*2 chars long
   5101  *                          userhash zero-terminated string
   5102  * @param bin_buf_size the size of the @a userhash_bin buffer, must be
   5103  *                     at least #MHD_digest_get_hash_size(algo3)*2+1 chars long
   5104  * @return MHD_YES on success,
   5105  *         MHD_NO if @a bin_buf_size is too small or if @a algo3 algorithm is
   5106  *         not supported (or external error has occurred,
   5107  *         see #MHD_FEATURE_EXTERN_HASH).
   5108  * @sa #MHD_digest_auth_calc_userhash()
   5109  * @note Available since #MHD_VERSION 0x00097701
   5110  * @ingroup authentication
   5111  */
   5112 _MHD_EXTERN enum MHD_Result
   5113 MHD_digest_auth_calc_userhash_hex (enum MHD_DigestAuthAlgo3 algo3,
   5114                                    const char *username,
   5115                                    const char *realm,
   5116                                    char *userhash_hex,
   5117                                    size_t hex_buf_size);
   5118 
   5119 
   5120 /**
   5121  * The type of username used by client in Digest Authorization header
   5122  *
   5123  * Values are sorted so simplified checks could be used.
   5124  * For example:
   5125  * * (value <= MHD_DIGEST_AUTH_UNAME_TYPE_INVALID) is true if no valid username
   5126  *   is provided by the client
   5127  * * (value >= MHD_DIGEST_AUTH_UNAME_TYPE_USERHASH) is true if username is
   5128  *   provided in any form
   5129  * * (value >= MHD_DIGEST_AUTH_UNAME_TYPE_STANDARD) is true if username is
   5130  *   provided in clear text (no userhash matching is needed)
   5131  *
   5132  * @note Available since #MHD_VERSION 0x00097701
   5133  */
   5134 enum MHD_DigestAuthUsernameType
   5135 {
   5136   /**
   5137    * No username parameter in in Digest Authorization header.
   5138    * This should be treated as an error.
   5139    */
   5140   MHD_DIGEST_AUTH_UNAME_TYPE_MISSING = 0,
   5141 
   5142   /**
   5143    * The 'username' parameter is used to specify the username.
   5144    */
   5145   MHD_DIGEST_AUTH_UNAME_TYPE_STANDARD = (1 << 2),
   5146 
   5147   /**
   5148    * The username is specified by 'username*' parameter with
   5149    * the extended notation (see RFC 5987 #section-3.2.1).
   5150    * The only difference between standard and extended types is
   5151    * the way how username value is encoded in the header.
   5152    */
   5153   MHD_DIGEST_AUTH_UNAME_TYPE_EXTENDED = (1 << 3),
   5154 
   5155   /**
   5156    * The username provided in form of 'userhash' as
   5157    * specified by RFC 7616 #section-3.4.4.
   5158    * @sa #MHD_digest_auth_calc_userhash_hex(), #MHD_digest_auth_calc_userhash()
   5159    */
   5160   MHD_DIGEST_AUTH_UNAME_TYPE_USERHASH = (1 << 1),
   5161 
   5162   /**
   5163    * The invalid combination of username parameters are used by client.
   5164    * Either:
   5165    * * both 'username' and 'username*' are used
   5166    * * 'username*' is used with 'userhash=true'
   5167    * * 'username*' used with invalid extended notation
   5168    * * 'username' is not hexadecimal string, while 'userhash' set to 'true'
   5169    */
   5170   MHD_DIGEST_AUTH_UNAME_TYPE_INVALID = (1 << 0)
   5171 } _MHD_FIXED_ENUM;
   5172 
   5173 /**
   5174  * The QOP ('quality of protection') types.
   5175  * @note Available since #MHD_VERSION 0x00097701
   5176  */
   5177 enum MHD_DigestAuthQOP
   5178 {
   5179   /**
   5180    * Invalid/unknown QOP.
   5181    * Used in struct MHD_DigestAuthInfo to indicate client value that
   5182    * cannot by identified.
   5183    */
   5184   MHD_DIGEST_AUTH_QOP_INVALID = 0,
   5185 
   5186   /**
   5187    * No QOP parameter.
   5188    * As described in old RFC 2069 original specification.
   5189    * This mode is not allowed by latest RFCs and should be used only to
   5190    * communicate with clients that do not support more modern modes (with QOP
   5191    * parameter).
   5192    * This mode is less secure than other modes and inefficient.
   5193    */
   5194   MHD_DIGEST_AUTH_QOP_NONE = 1 << 0,
   5195 
   5196   /**
   5197    * The 'auth' QOP type.
   5198    */
   5199   MHD_DIGEST_AUTH_QOP_AUTH = 1 << 1,
   5200 
   5201   /**
   5202    * The 'auth-int' QOP type.
   5203    * Not supported by MHD for authentication.
   5204    */
   5205   MHD_DIGEST_AUTH_QOP_AUTH_INT = 1 << 2
   5206 } _MHD_FIXED_FLAGS_ENUM;
   5207 
   5208 /**
   5209  * The QOP ('quality of protection') types, multiple selection.
   5210  *
   5211  * #MHD_DigestAuthQOP always can be casted to #MHD_DigestAuthMultiQOP, but
   5212  * not vice versa.
   5213  *
   5214  * @note Available since #MHD_VERSION 0x00097701
   5215  */
   5216 enum MHD_DigestAuthMultiQOP
   5217 {
   5218   /**
   5219    * Invalid/unknown QOP.
   5220    */
   5221   MHD_DIGEST_AUTH_MULT_QOP_INVALID = MHD_DIGEST_AUTH_QOP_INVALID,
   5222 
   5223   /**
   5224    * No QOP parameter.
   5225    * As described in old RFC 2069 original specification.
   5226    * This mode is not allowed by latest RFCs and should be used only to
   5227    * communicate with clients that do not support more modern modes (with QOP
   5228    * parameter).
   5229    * This mode is less secure than other modes and inefficient.
   5230    */
   5231   MHD_DIGEST_AUTH_MULT_QOP_NONE = MHD_DIGEST_AUTH_QOP_NONE,
   5232 
   5233   /**
   5234    * The 'auth' QOP type.
   5235    */
   5236   MHD_DIGEST_AUTH_MULT_QOP_AUTH = MHD_DIGEST_AUTH_QOP_AUTH,
   5237 
   5238   /**
   5239    * The 'auth-int' QOP type.
   5240    * Not supported by MHD.
   5241    * Reserved value.
   5242    */
   5243   MHD_DIGEST_AUTH_MULT_QOP_AUTH_INT = MHD_DIGEST_AUTH_QOP_AUTH_INT,
   5244 
   5245   /**
   5246    * The 'auth' QOP type OR the old RFC2069 (no QOP) type.
   5247    * In other words: any types except 'auth-int'.
   5248    * RFC2069-compatible mode is allowed, thus this value should be used only
   5249    * when it is really necessary.
   5250    */
   5251   MHD_DIGEST_AUTH_MULT_QOP_ANY_NON_INT =
   5252     MHD_DIGEST_AUTH_QOP_NONE | MHD_DIGEST_AUTH_QOP_AUTH,
   5253 
   5254   /**
   5255    * Any 'auth' QOP type ('auth' or 'auth-int').
   5256    * Currently supported as 'auth' QOP type only.
   5257    */
   5258   MHD_DIGEST_AUTH_MULT_QOP_AUTH_ANY =
   5259     MHD_DIGEST_AUTH_QOP_AUTH | MHD_DIGEST_AUTH_QOP_AUTH_INT
   5260 } _MHD_FIXED_ENUM;
   5261 
   5262 /**
   5263  * The invalid value of 'nc' parameter in client Digest Authorization header.
   5264  * @note Available since #MHD_VERSION 0x00097701
   5265  */
   5266 #define MHD_DIGEST_AUTH_INVALID_NC_VALUE        (0)
   5267 
   5268 /**
   5269  * Information from Digest Authorization client's header.
   5270  *
   5271  * All buffers pointed by any struct members are freed when #MHD_free() is
   5272  * called for pointer to this structure.
   5273  *
   5274  * Application may modify buffers as needed until #MHD_free() is called for
   5275  * pointer to this structure
   5276  * @note Available since #MHD_VERSION 0x00097701
   5277  */
   5278 struct MHD_DigestAuthInfo
   5279 {
   5280   /**
   5281    * The algorithm as defined by client.
   5282    * Set automatically to MD5 if not specified by client.
   5283    * @warning Do not be confused with #MHD_DigestAuthAlgorithm,
   5284    *          which uses other values!
   5285    */
   5286   enum MHD_DigestAuthAlgo3 algo3;
   5287 
   5288   /**
   5289    * The type of username used by client.
   5290    */
   5291   enum MHD_DigestAuthUsernameType uname_type;
   5292 
   5293   /**
   5294    * The username string.
   5295    * Used only if username type is standard or extended, always NULL otherwise.
   5296    * If extended notation is used, this string is pct-decoded string
   5297    * with charset and language tag removed (i.e. it is original username
   5298    * extracted from the extended notation).
   5299    * When userhash is used by the client, this member is NULL and
   5300    * @a userhash_hex and @a userhash_bin are set.
   5301    * The buffer pointed by the @a username becomes invalid when the pointer
   5302    * to the structure is freed by #MHD_free().
   5303    */
   5304   char *username;
   5305 
   5306   /**
   5307    * The length of the @a username.
   5308    * When the @a username is NULL, this member is always zero.
   5309    */
   5310   size_t username_len;
   5311 
   5312   /**
   5313    * The userhash string.
   5314    * Valid only if username type is userhash.
   5315    * This is unqoted string without decoding of the hexadecimal
   5316    * digits (as provided by the client).
   5317    * The buffer pointed by the @a userhash_hex becomes invalid when the pointer
   5318    * to the structure is freed by #MHD_free().
   5319    * @sa #MHD_digest_auth_calc_userhash_hex()
   5320    */
   5321   char *userhash_hex;
   5322 
   5323   /**
   5324    * The length of the @a userhash_hex in characters.
   5325    * The valid size should be #MHD_digest_get_hash_size(algo3) * 2 characters.
   5326    * When the @a userhash_hex is NULL, this member is always zero.
   5327    */
   5328   size_t userhash_hex_len;
   5329 
   5330   /**
   5331    * The userhash decoded to binary form.
   5332    * Used only if username type is userhash, always NULL otherwise.
   5333    * When not NULL, this points to binary sequence @a userhash_hex_len /2 bytes
   5334    * long.
   5335    * The valid size should be #MHD_digest_get_hash_size(algo3) bytes.
   5336    * The buffer pointed by the @a userhash_bin becomes invalid when the pointer
   5337    * to the structure is freed by #MHD_free().
   5338    * @warning This is a binary data, no zero termination.
   5339    * @warning To avoid buffer overruns, always check the size of the data before
   5340    *          use, because @a userhash_bin can point even to zero-sized
   5341    *          data.
   5342    * @sa #MHD_digest_auth_calc_userhash()
   5343    */
   5344   uint8_t *userhash_bin;
   5345 
   5346   /**
   5347    * The 'opaque' parameter value, as specified by client.
   5348    * NULL if not specified by client.
   5349    * The buffer pointed by the @a opaque becomes invalid when the pointer
   5350    * to the structure is freed by #MHD_free().
   5351    */
   5352   char *opaque;
   5353 
   5354   /**
   5355    * The length of the @a opaque.
   5356    * When the @a opaque is NULL, this member is always zero.
   5357    */
   5358   size_t opaque_len;
   5359 
   5360   /**
   5361    * The 'realm' parameter value, as specified by client.
   5362    * NULL if not specified by client.
   5363    * The buffer pointed by the @a realm becomes invalid when the pointer
   5364    * to the structure is freed by #MHD_free().
   5365    */
   5366   char *realm;
   5367 
   5368   /**
   5369    * The length of the @a realm.
   5370    * When the @a realm is NULL, this member is always zero.
   5371    */
   5372   size_t realm_len;
   5373 
   5374   /**
   5375    * The 'qop' parameter value.
   5376    */
   5377   enum MHD_DigestAuthQOP qop;
   5378 
   5379   /**
   5380    * The length of the 'cnonce' parameter value, including possible
   5381    * backslash-escape characters.
   5382    * 'cnonce' is used in hash calculation, which is CPU-intensive procedure.
   5383    * An application may want to reject too large cnonces to limit the CPU load.
   5384    * A few kilobytes is a reasonable limit, typically cnonce is just 32-160
   5385    * characters long.
   5386    */
   5387   size_t cnonce_len;
   5388 
   5389   /**
   5390    * The nc parameter value.
   5391    * Can be used by application to limit the number of nonce re-uses. If @a nc
   5392    * is higher than application wants to allow, then "auth required" response
   5393    * with 'stale=true' could be used to force client to retry with the fresh
   5394    * 'nonce'.
   5395    * If not specified by client or does not have hexadecimal digits only, the
   5396    * value is #MHD_DIGEST_AUTH_INVALID_NC_VALUE.
   5397    */
   5398   uint32_t nc;
   5399 };
   5400 
   5401 
   5402 /**
   5403  * Get information about Digest Authorization client's header.
   5404  *
   5405  * @param connection The MHD connection structure
   5406  * @return NULL if no valid Digest Authorization header is used in the request;
   5407  *         a pointer to the structure with information if the valid request
   5408  *         header found, free using #MHD_free().
   5409  * @sa #MHD_digest_auth_get_username3()
   5410  * @note Available since #MHD_VERSION 0x00097701
   5411  * @ingroup authentication
   5412  */
   5413 _MHD_EXTERN struct MHD_DigestAuthInfo *
   5414 MHD_digest_auth_get_request_info3 (struct MHD_Connection *connection);
   5415 
   5416 
   5417 /**
   5418  * Information from Digest Authorization client's header.
   5419  *
   5420  * All buffers pointed by any struct members are freed when #MHD_free() is
   5421  * called for pointer to this structure.
   5422  *
   5423  * Application may modify buffers as needed until #MHD_free() is called for
   5424  * pointer to this structure
   5425  * @note Available since #MHD_VERSION 0x00097701
   5426  */
   5427 struct MHD_DigestAuthUsernameInfo
   5428 {
   5429   /**
   5430    * The algorithm as defined by client.
   5431    * Set automatically to MD5 if not specified by client.
   5432    * @warning Do not be confused with #MHD_DigestAuthAlgorithm,
   5433    *          which uses other values!
   5434    */
   5435   enum MHD_DigestAuthAlgo3 algo3;
   5436 
   5437   /**
   5438    * The type of username used by client.
   5439    * The 'invalid' and 'missing' types are not used in this structure,
   5440    * instead NULL is returned by #MHD_digest_auth_get_username3().
   5441    */
   5442   enum MHD_DigestAuthUsernameType uname_type;
   5443 
   5444   /**
   5445    * The username string.
   5446    * Used only if username type is standard or extended, always NULL otherwise.
   5447    * If extended notation is used, this string is pct-decoded string
   5448    * with charset and language tag removed (i.e. it is original username
   5449    * extracted from the extended notation).
   5450    * When userhash is used by the client, this member is NULL and
   5451    * @a userhash_hex and @a userhash_bin are set.
   5452    * The buffer pointed by the @a username becomes invalid when the pointer
   5453    * to the structure is freed by #MHD_free().
   5454    */
   5455   char *username;
   5456 
   5457   /**
   5458    * The length of the @a username.
   5459    * When the @a username is NULL, this member is always zero.
   5460    */
   5461   size_t username_len;
   5462 
   5463   /**
   5464    * The userhash string.
   5465    * Valid only if username type is userhash.
   5466    * This is unqoted string without decoding of the hexadecimal
   5467    * digits (as provided by the client).
   5468    * The buffer pointed by the @a userhash_hex becomes invalid when the pointer
   5469    * to the structure is freed by #MHD_free().
   5470    * @sa #MHD_digest_auth_calc_userhash_hex()
   5471    */
   5472   char *userhash_hex;
   5473 
   5474   /**
   5475    * The length of the @a userhash_hex in characters.
   5476    * The valid size should be #MHD_digest_get_hash_size(algo3) * 2 characters.
   5477    * When the @a userhash_hex is NULL, this member is always zero.
   5478    */
   5479   size_t userhash_hex_len;
   5480 
   5481   /**
   5482    * The userhash decoded to binary form.
   5483    * Used only if username type is userhash, always NULL otherwise.
   5484    * When not NULL, this points to binary sequence @a userhash_hex_len /2 bytes
   5485    * long.
   5486    * The valid size should be #MHD_digest_get_hash_size(algo3) bytes.
   5487    * The buffer pointed by the @a userhash_bin becomes invalid when the pointer
   5488    * to the structure is freed by #MHD_free().
   5489    * @warning This is a binary data, no zero termination.
   5490    * @warning To avoid buffer overruns, always check the size of the data before
   5491    *          use, because @a userhash_bin can point even to zero-sized
   5492    *          data.
   5493    * @sa #MHD_digest_auth_calc_userhash()
   5494    */
   5495   uint8_t *userhash_bin;
   5496 };
   5497 
   5498 
   5499 /**
   5500  * Get the username from Digest Authorization client's header.
   5501  *
   5502  * @param connection The MHD connection structure
   5503  * @return NULL if no valid Digest Authorization header is used in the request,
   5504  *         or no username parameter is present in the header, or username is
   5505  *         provided incorrectly by client (see description for
   5506  *         #MHD_DIGEST_AUTH_UNAME_TYPE_INVALID);
   5507  *         a pointer structure with information if the valid request header
   5508  *         found, free using #MHD_free().
   5509  * @sa #MHD_digest_auth_get_request_info3() provides more complete information
   5510  * @note Available since #MHD_VERSION 0x00097701
   5511  * @ingroup authentication
   5512  */
   5513 _MHD_EXTERN struct MHD_DigestAuthUsernameInfo *
   5514 MHD_digest_auth_get_username3 (struct MHD_Connection *connection);
   5515 
   5516 
   5517 /**
   5518  * The result of digest authentication of the client.
   5519  *
   5520  * All error values are zero or negative.
   5521  *
   5522  * @note Available since #MHD_VERSION 0x00097701
   5523  */
   5524 enum MHD_DigestAuthResult
   5525 {
   5526   /**
   5527    * Authentication OK.
   5528    */
   5529   MHD_DAUTH_OK = 1,
   5530 
   5531   /**
   5532    * General error, like "out of memory".
   5533    */
   5534   MHD_DAUTH_ERROR = 0,
   5535 
   5536   /**
   5537    * No "Authorization" header or wrong format of the header.
   5538    * Also may be returned if required parameters in client Authorisation header
   5539    * are missing or broken (in invalid format).
   5540    */
   5541   MHD_DAUTH_WRONG_HEADER = -1,
   5542 
   5543   /**
   5544    * Wrong 'username'.
   5545    */
   5546   MHD_DAUTH_WRONG_USERNAME = -2,
   5547 
   5548   /**
   5549    * Wrong 'realm'.
   5550    */
   5551   MHD_DAUTH_WRONG_REALM = -3,
   5552 
   5553   /**
   5554    * Wrong 'URI' (or URI parameters).
   5555    */
   5556   MHD_DAUTH_WRONG_URI = -4,
   5557 
   5558   /**
   5559    * Wrong 'qop'.
   5560    */
   5561   MHD_DAUTH_WRONG_QOP = -5,
   5562 
   5563   /**
   5564    * Wrong 'algorithm'.
   5565    */
   5566   MHD_DAUTH_WRONG_ALGO = -6,
   5567 
   5568   /**
   5569    * Too large (>64 KiB) Authorization parameter value.
   5570    */
   5571   MHD_DAUTH_TOO_LARGE = -15,
   5572 
   5573   /* The different form of naming is intentionally used for the results below,
   5574    * as they are more important */
   5575 
   5576   /**
   5577    * The 'nonce' is too old. Suggest the client to retry with the same
   5578    * username and password to get the fresh 'nonce'.
   5579    * The validity of the 'nonce' may be not checked.
   5580    */
   5581   MHD_DAUTH_NONCE_STALE = -17,
   5582 
   5583   /**
   5584    * The 'nonce' was generated by MHD for other conditions.
   5585    * This value is only returned if #MHD_OPTION_DIGEST_AUTH_NONCE_BIND_TYPE
   5586    * is set to anything other than #MHD_DAUTH_BIND_NONCE_NONE.
   5587    * The interpretation of this code could be different. For example, if
   5588    * #MHD_DAUTH_BIND_NONCE_URI is set and client just used the same 'nonce' for
   5589    * another URI, the code could be handled as #MHD_DAUTH_NONCE_STALE as
   5590    * RFCs allow nonces re-using for other URIs in the same "protection
   5591    * space". However, if only #MHD_DAUTH_BIND_NONCE_CLIENT_IP bit is set and
   5592    * it is know that clients have fixed IP addresses, this return code could
   5593    * be handled like #MHD_DAUTH_NONCE_WRONG.
   5594    */
   5595   MHD_DAUTH_NONCE_OTHER_COND = -18,
   5596 
   5597   /**
   5598    * The 'nonce' is wrong. May indicate an attack attempt.
   5599    */
   5600   MHD_DAUTH_NONCE_WRONG = -33,
   5601 
   5602   /**
   5603    * The 'response' is wrong. Typically it means that wrong password used.
   5604    * May indicate an attack attempt.
   5605    */
   5606   MHD_DAUTH_RESPONSE_WRONG = -34
   5607 };
   5608 
   5609 
   5610 /**
   5611  * Authenticates the authorization header sent by the client.
   5612  *
   5613  * If RFC2069 mode is allowed by setting bit #MHD_DIGEST_AUTH_QOP_NONE in
   5614  * @a mqop and the client uses this mode, then server generated nonces are
   5615  * used as one-time nonces because nonce-count is not supported in this old RFC.
   5616  * Communication in this mode is very inefficient, especially if the client
   5617  * requests several resources one-by-one as for every request a new nonce must
   5618  * be generated and client repeats all requests twice (first time to get a new
   5619  * nonce and second time to perform an authorised request).
   5620  *
   5621  * @param connection the MHD connection structure
   5622  * @param realm the realm for authorization of the client
   5623  * @param username the username to be authenticated, must be in clear text
   5624  *                 even if userhash is used by the client
   5625  * @param password the password matching the @a username (and the @a realm)
   5626  * @param nonce_timeout the period of seconds since nonce generation, when
   5627  *                      the nonce is recognised as valid and not stale;
   5628  *                      if zero is specified then daemon default value is used.
   5629  * @param max_nc the maximum allowed nc (Nonce Count) value, if client's nc
   5630  *               exceeds the specified value then MHD_DAUTH_NONCE_STALE is
   5631  *               returned;
   5632  *               if zero is specified then daemon default value is used.
   5633  * @param mqop the QOP to use
   5634  * @param malgo3 digest algorithms allowed to use, fail if algorithm used
   5635  *               by the client is not allowed by this parameter
   5636  * @return #MHD_DAUTH_OK if authenticated,
   5637  *         the error code otherwise
   5638  * @note Available since #MHD_VERSION 0x00097708
   5639  * @ingroup authentication
   5640  */
   5641 _MHD_EXTERN enum MHD_DigestAuthResult
   5642 MHD_digest_auth_check3 (struct MHD_Connection *connection,
   5643                         const char *realm,
   5644                         const char *username,
   5645                         const char *password,
   5646                         unsigned int nonce_timeout,
   5647                         uint32_t max_nc,
   5648                         enum MHD_DigestAuthMultiQOP mqop,
   5649                         enum MHD_DigestAuthMultiAlgo3 malgo3);
   5650 
   5651 
   5652 /**
   5653  * Calculate userdigest, return it as a binary data.
   5654  *
   5655  * The "userdigest" is the hash of the "username:realm:password" string.
   5656  *
   5657  * The "userdigest" can be used to avoid storing the password in clear text
   5658  * in database/files
   5659  *
   5660  * This function is designed to improve security of stored credentials,
   5661  * the "userdigest" does not improve security of the authentication process.
   5662  *
   5663  * The results can be used to store username & userdigest pairs instead of
   5664  * username & password pairs. To further improve security, application may
   5665  * store username & userhash & userdigest triplets.
   5666  *
   5667  * @param algo3 the digest algorithm
   5668  * @param username the username
   5669  * @param realm the realm
   5670  * @param password the password
   5671  * @param[out] userdigest_bin the output buffer for userdigest;
   5672  *                            if this function succeeds, then this buffer has
   5673  *                            #MHD_digest_get_hash_size(algo3) bytes of
   5674  *                            userdigest upon return
   5675  * @param bin_buf_size the size of the @a userdigest_bin buffer, must be
   5676  *                     at least #MHD_digest_get_hash_size(algo3) bytes long
   5677  * @return MHD_YES on success,
   5678  *         MHD_NO if @a userdigest_bin is too small or if @a algo3 algorithm is
   5679  *         not supported (or external error has occurred,
   5680  *         see #MHD_FEATURE_EXTERN_HASH).
   5681  * @sa #MHD_digest_auth_check_digest3()
   5682  * @note Available since #MHD_VERSION 0x00097701
   5683  * @ingroup authentication
   5684  */
   5685 _MHD_EXTERN enum MHD_Result
   5686 MHD_digest_auth_calc_userdigest (enum MHD_DigestAuthAlgo3 algo3,
   5687                                  const char *username,
   5688                                  const char *realm,
   5689                                  const char *password,
   5690                                  void *userdigest_bin,
   5691                                  size_t bin_buf_size);
   5692 
   5693 
   5694 /**
   5695  * Authenticates the authorization header sent by the client by using
   5696  * hash of "username:realm:password".
   5697  *
   5698  * If RFC2069 mode is allowed by setting bit #MHD_DIGEST_AUTH_QOP_NONE in
   5699  * @a mqop and the client uses this mode, then server generated nonces are
   5700  * used as one-time nonces because nonce-count is not supported in this old RFC.
   5701  * Communication in this mode is very inefficient, especially if the client
   5702  * requests several resources one-by-one as for every request a new nonce must
   5703  * be generated and client repeats all requests twice (first time to get a new
   5704  * nonce and second time to perform an authorised request).
   5705  *
   5706  * @param connection the MHD connection structure
   5707  * @param realm the realm for authorization of the client
   5708  * @param username the username to be authenticated, must be in clear text
   5709  *                 even if userhash is used by the client
   5710  * @param userdigest the precalculated binary hash of the string
   5711  *                   "username:realm:password",
   5712  *                   see #MHD_digest_auth_calc_userdigest()
   5713  * @param userdigest_size the size of the @a userdigest in bytes, must match the
   5714  *                        hashing algorithm (see #MHD_MD5_DIGEST_SIZE,
   5715  *                        #MHD_SHA256_DIGEST_SIZE, #MHD_SHA512_256_DIGEST_SIZE,
   5716  *                        #MHD_digest_get_hash_size())
   5717  * @param nonce_timeout the period of seconds since nonce generation, when
   5718  *                      the nonce is recognised as valid and not stale;
   5719  *                      if zero is specified then daemon default value is used.
   5720  * @param max_nc the maximum allowed nc (Nonce Count) value, if client's nc
   5721  *               exceeds the specified value then MHD_DAUTH_NONCE_STALE is
   5722  *               returned;
   5723  *               if zero is specified then daemon default value is used.
   5724  * @param mqop the QOP to use
   5725  * @param malgo3 digest algorithms allowed to use, fail if algorithm used
   5726  *               by the client is not allowed by this parameter;
   5727  *               more than one base algorithms (MD5, SHA-256, SHA-512/256)
   5728  *               cannot be used at the same time for this function
   5729  *               as @a userdigest must match specified algorithm
   5730  * @return #MHD_DAUTH_OK if authenticated,
   5731  *         the error code otherwise
   5732  * @sa #MHD_digest_auth_calc_userdigest()
   5733  * @note Available since #MHD_VERSION 0x00097701
   5734  * @ingroup authentication
   5735  */
   5736 _MHD_EXTERN enum MHD_DigestAuthResult
   5737 MHD_digest_auth_check_digest3 (struct MHD_Connection *connection,
   5738                                const char *realm,
   5739                                const char *username,
   5740                                const void *userdigest,
   5741                                size_t userdigest_size,
   5742                                unsigned int nonce_timeout,
   5743                                uint32_t max_nc,
   5744                                enum MHD_DigestAuthMultiQOP mqop,
   5745                                enum MHD_DigestAuthMultiAlgo3 malgo3);
   5746 
   5747 
   5748 /**
   5749  * Queues a response to request authentication from the client
   5750  *
   5751  * This function modifies provided @a response. The @a response must not be
   5752  * reused and should be destroyed (by #MHD_destroy_response()) after call of
   5753  * this function.
   5754  *
   5755  * If @a mqop allows both RFC 2069 (MHD_DIGEST_AUTH_QOP_NONE) and QOP with
   5756  * value, then response is formed like if MHD_DIGEST_AUTH_QOP_NONE bit was
   5757  * not set, because such response should be backward-compatible with RFC 2069.
   5758  *
   5759  * If @a mqop allows only MHD_DIGEST_AUTH_MULT_QOP_NONE, then the response is
   5760  * formed in strict accordance with RFC 2069 (no 'qop', no 'userhash', no
   5761  * 'charset'). For better compatibility with clients, it is recommended (but
   5762  * not required) to set @a domain to NULL in this mode.
   5763  *
   5764  * @param connection the MHD connection structure
   5765  * @param realm the realm presented to the client
   5766  * @param opaque the string for opaque value, can be NULL, but NULL is
   5767  *               not recommended for better compatibility with clients;
   5768  *               the recommended format is hex or Base64 encoded string
   5769  * @param domain the optional space-separated list of URIs for which the
   5770  *               same authorisation could be used, URIs can be in form
   5771  *               "path-absolute" (the path for the same host with initial slash)
   5772  *               or in form "absolute-URI" (the full path with protocol), in
   5773  *               any case client may assume that URI is in the same "protection
   5774  *               space" if it starts with any of values specified here;
   5775  *               could be NULL (clients typically assume that the same
   5776  *               credentials could be used for any URI on the same host);
   5777  *               this list provides information for the client only and does
   5778  *               not actually restrict anything on the server side
   5779  * @param response the reply to send; should contain the "access denied"
   5780  *                 body;
   5781  *                 note: this function sets the "WWW Authenticate" header and
   5782  *                 the caller should not set this header;
   5783  *                 the NULL is tolerated
   5784  * @param signal_stale if set to #MHD_YES then indication of stale nonce used in
   5785  *                     the client's request is signalled by adding 'stale=true'
   5786  *                     to the authentication header, this instructs the client
   5787  *                     to retry immediately with the new nonce and the same
   5788  *                     credentials, without asking user for the new password
   5789  * @param mqop the QOP to use
   5790  * @param malgo3 digest algorithm to use; if several algorithms are allowed
   5791  *               then MD5 is preferred (currently, may be changed in next
   5792  *               versions)
   5793  * @param userhash_support if set to non-zero value (#MHD_YES) then support of
   5794  *                         userhash is indicated, allowing client to provide
   5795  *                         hash("username:realm") instead of the username in
   5796  *                         clear text;
   5797  *                         note that clients are allowed to provide the username
   5798  *                         in cleartext even if this parameter set to non-zero;
   5799  *                         when userhash is used, application must be ready to
   5800  *                         identify users by provided userhash value instead of
   5801  *                         username; see #MHD_digest_auth_calc_userhash() and
   5802  *                         #MHD_digest_auth_calc_userhash_hex()
   5803  * @param prefer_utf8 if not set to #MHD_NO, parameter 'charset=UTF-8' is
   5804  *                    added, indicating for the client that UTF-8 encoding for
   5805  *                    the username is preferred
   5806  * @return #MHD_YES on success, #MHD_NO otherwise
   5807  * @note Available since #MHD_VERSION 0x00097701
   5808  * @ingroup authentication
   5809  */
   5810 _MHD_EXTERN enum MHD_Result
   5811 MHD_queue_auth_required_response3 (struct MHD_Connection *connection,
   5812                                    const char *realm,
   5813                                    const char *opaque,
   5814                                    const char *domain,
   5815                                    struct MHD_Response *response,
   5816                                    int signal_stale,
   5817                                    enum MHD_DigestAuthMultiQOP mqop,
   5818                                    enum MHD_DigestAuthMultiAlgo3 algo,
   5819                                    int userhash_support,
   5820                                    int prefer_utf8);
   5821 
   5822 
   5823 /**
   5824  * Constant to indicate that the nonce of the provided
   5825  * authentication code was wrong.
   5826  * Used as return code by #MHD_digest_auth_check(), #MHD_digest_auth_check2(),
   5827  * #MHD_digest_auth_check_digest(), #MHD_digest_auth_check_digest2().
   5828  * @ingroup authentication
   5829  */
   5830 #define MHD_INVALID_NONCE -1
   5831 
   5832 
   5833 /**
   5834  * Get the username from the authorization header sent by the client
   5835  *
   5836  * This function supports username in standard and extended notations.
   5837  * "userhash" is not supported by this function.
   5838  *
   5839  * @param connection The MHD connection structure
   5840  * @return NULL if no username could be found, username provided as
   5841  *         "userhash", extended notation broken or memory allocation error
   5842  *         occurs;
   5843  *         a pointer to the username if found, free using #MHD_free().
   5844  * @warning Returned value must be freed by #MHD_free().
   5845  * @sa #MHD_digest_auth_get_username3()
   5846  * @ingroup authentication
   5847  */
   5848 _MHD_EXTERN char *
   5849 MHD_digest_auth_get_username (struct MHD_Connection *connection);
   5850 
   5851 
   5852 /**
   5853  * Which digest algorithm should MHD use for HTTP digest authentication?
   5854  * Used as parameter for #MHD_digest_auth_check2(),
   5855  * #MHD_digest_auth_check_digest2(), #MHD_queue_auth_fail_response2().
   5856  */
   5857 enum MHD_DigestAuthAlgorithm
   5858 {
   5859 
   5860   /**
   5861    * MHD should pick (currently defaults to MD5).
   5862    */
   5863   MHD_DIGEST_ALG_AUTO = 0,
   5864 
   5865   /**
   5866    * Force use of MD5.
   5867    */
   5868   MHD_DIGEST_ALG_MD5,
   5869 
   5870   /**
   5871    * Force use of SHA-256.
   5872    */
   5873   MHD_DIGEST_ALG_SHA256
   5874 
   5875 } _MHD_FIXED_ENUM;
   5876 
   5877 
   5878 /**
   5879  * Authenticates the authorization header sent by the client.
   5880  *
   5881  * @param connection The MHD connection structure
   5882  * @param realm The realm presented to the client
   5883  * @param username The username needs to be authenticated
   5884  * @param password The password used in the authentication
   5885  * @param nonce_timeout The amount of time for a nonce to be
   5886  *      invalid in seconds
   5887  * @param algo digest algorithms allowed for verification
   5888  * @return #MHD_YES if authenticated, #MHD_NO if not,
   5889  *         #MHD_INVALID_NONCE if nonce is invalid or stale
   5890  * @note Available since #MHD_VERSION 0x00096200
   5891  * @deprecated use MHD_digest_auth_check3()
   5892  * @ingroup authentication
   5893  */
   5894 _MHD_EXTERN int
   5895 MHD_digest_auth_check2 (struct MHD_Connection *connection,
   5896                         const char *realm,
   5897                         const char *username,
   5898                         const char *password,
   5899                         unsigned int nonce_timeout,
   5900                         enum MHD_DigestAuthAlgorithm algo);
   5901 
   5902 
   5903 /**
   5904  * Authenticates the authorization header sent by the client.
   5905  * Uses #MHD_DIGEST_ALG_MD5 (for now, for backwards-compatibility).
   5906  * Note that this MAY change to #MHD_DIGEST_ALG_AUTO in the future.
   5907  * If you want to be sure you get MD5, use #MHD_digest_auth_check2()
   5908  * and specify MD5 explicitly.
   5909  *
   5910  * @param connection The MHD connection structure
   5911  * @param realm The realm presented to the client
   5912  * @param username The username needs to be authenticated
   5913  * @param password The password used in the authentication
   5914  * @param nonce_timeout The amount of time for a nonce to be
   5915  *      invalid in seconds
   5916  * @return #MHD_YES if authenticated, #MHD_NO if not,
   5917  *         #MHD_INVALID_NONCE if nonce is invalid or stale
   5918  * @deprecated use MHD_digest_auth_check3()
   5919  * @ingroup authentication
   5920  */
   5921 _MHD_EXTERN int
   5922 MHD_digest_auth_check (struct MHD_Connection *connection,
   5923                        const char *realm,
   5924                        const char *username,
   5925                        const char *password,
   5926                        unsigned int nonce_timeout);
   5927 
   5928 
   5929 /**
   5930  * Authenticates the authorization header sent by the client.
   5931  *
   5932  * @param connection The MHD connection structure
   5933  * @param realm The realm presented to the client
   5934  * @param username The username needs to be authenticated
   5935  * @param digest An `unsigned char *' pointer to the binary MD5 sum
   5936  *      for the precalculated hash value "username:realm:password"
   5937  *      of @a digest_size bytes
   5938  * @param digest_size number of bytes in @a digest (size must match @a algo!)
   5939  * @param nonce_timeout The amount of time for a nonce to be
   5940  *      invalid in seconds
   5941  * @param algo digest algorithm allowed for verification; exactly one
   5942  *      algorithm must be named, as @a digest is a hash produced by one
   5943  *      specific algorithm.  #MHD_DIGEST_ALG_AUTO cannot be used here
   5944  *      and makes this function return #MHD_NO
   5945  * @return #MHD_YES if authenticated, #MHD_NO if not,
   5946  *         #MHD_INVALID_NONCE if nonce is invalid or stale
   5947  * @note Available since #MHD_VERSION 0x00096200
   5948  * @deprecated use MHD_digest_auth_check_digest3()
   5949  * @ingroup authentication
   5950  */
   5951 _MHD_EXTERN int
   5952 MHD_digest_auth_check_digest2 (struct MHD_Connection *connection,
   5953                                const char *realm,
   5954                                const char *username,
   5955                                const uint8_t *digest,
   5956                                size_t digest_size,
   5957                                unsigned int nonce_timeout,
   5958                                enum MHD_DigestAuthAlgorithm algo);
   5959 
   5960 
   5961 /**
   5962  * Authenticates the authorization header sent by the client
   5963  * Uses #MHD_DIGEST_ALG_MD5 (required, as @a digest is of fixed
   5964  * size).
   5965  *
   5966  * @param connection The MHD connection structure
   5967  * @param realm The realm presented to the client
   5968  * @param username The username needs to be authenticated
   5969  * @param digest An `unsigned char *' pointer to the binary hash
   5970  *    for the precalculated hash value "username:realm:password";
   5971  *    length must be #MHD_MD5_DIGEST_SIZE bytes
   5972  * @param nonce_timeout The amount of time for a nonce to be
   5973  *      invalid in seconds
   5974  * @return #MHD_YES if authenticated, #MHD_NO if not,
   5975  *         #MHD_INVALID_NONCE if nonce is invalid or stale
   5976  * @note Available since #MHD_VERSION 0x00096000
   5977  * @deprecated use #MHD_digest_auth_check_digest3()
   5978  * @ingroup authentication
   5979  */
   5980 _MHD_EXTERN int
   5981 MHD_digest_auth_check_digest (struct MHD_Connection *connection,
   5982                               const char *realm,
   5983                               const char *username,
   5984                               const uint8_t digest[MHD_MD5_DIGEST_SIZE],
   5985                               unsigned int nonce_timeout);
   5986 
   5987 
   5988 /**
   5989  * Queues a response to request authentication from the client
   5990  *
   5991  * This function modifies provided @a response. The @a response must not be
   5992  * reused and should be destroyed after call of this function.
   5993  *
   5994  * @param connection The MHD connection structure
   5995  * @param realm the realm presented to the client
   5996  * @param opaque string to user for opaque value
   5997  * @param response reply to send; should contain the "access denied"
   5998  *        body; note that this function will set the "WWW Authenticate"
   5999  *        header and that the caller should not do this; the NULL is tolerated
   6000  * @param signal_stale #MHD_YES if the nonce is stale to add
   6001  *        'stale=true' to the authentication header
   6002  * @param algo digest algorithm to use
   6003  * @return #MHD_YES on success, #MHD_NO otherwise
   6004  * @note Available since #MHD_VERSION 0x00096200
   6005  * @deprecated use MHD_queue_auth_required_response3()
   6006  * @ingroup authentication
   6007  */
   6008 _MHD_EXTERN enum MHD_Result
   6009 MHD_queue_auth_fail_response2 (struct MHD_Connection *connection,
   6010                                const char *realm,
   6011                                const char *opaque,
   6012                                struct MHD_Response *response,
   6013                                int signal_stale,
   6014                                enum MHD_DigestAuthAlgorithm algo);
   6015 
   6016 
   6017 /**
   6018  * Queues a response to request authentication from the client.
   6019  * For now uses MD5 (for backwards-compatibility). Still, if you
   6020  * need to be sure, use #MHD_queue_auth_fail_response2().
   6021  *
   6022  * This function modifies provided @a response. The @a response must not be
   6023  * reused and should be destroyed after call of this function.
   6024  *
   6025  * @param connection The MHD connection structure
   6026  * @param realm the realm presented to the client
   6027  * @param opaque string to user for opaque value
   6028  * @param response reply to send; should contain the "access denied"
   6029  *        body; note that this function will set the "WWW Authenticate"
   6030  *        header and that the caller should not do this; the NULL is tolerated
   6031  * @param signal_stale #MHD_YES if the nonce is stale to add
   6032  *        'stale=true' to the authentication header
   6033  * @return #MHD_YES on success, #MHD_NO otherwise
   6034  * @deprecated use MHD_queue_auth_required_response3()
   6035  * @ingroup authentication
   6036  */
   6037 _MHD_EXTERN enum MHD_Result
   6038 MHD_queue_auth_fail_response (struct MHD_Connection *connection,
   6039                               const char *realm,
   6040                               const char *opaque,
   6041                               struct MHD_Response *response,
   6042                               int signal_stale);
   6043 
   6044 
   6045 /* ********************* Basic Authentication functions *************** */
   6046 
   6047 
   6048 /**
   6049  * Information decoded from Basic Authentication client's header.
   6050  *
   6051  * The username and the password are technically allowed to have binary zeros,
   6052  * username_len and password_len could be used to detect such situations.
   6053  *
   6054  * The buffers pointed by username and password members are freed
   6055  * when #MHD_free() is called for pointer to this structure.
   6056  *
   6057  * Application may modify buffers as needed until #MHD_free() is called for
   6058  * pointer to this structure
   6059  */
   6060 struct MHD_BasicAuthInfo
   6061 {
   6062   /**
   6063    * The username, cannot be NULL.
   6064    * The buffer pointed by the @a username becomes invalid when the pointer
   6065    * to the structure is freed by #MHD_free().
   6066    */
   6067   char *username;
   6068 
   6069   /**
   6070    * The length of the @a username, not including zero-termination
   6071    */
   6072   size_t username_len;
   6073 
   6074   /**
   6075    * The password, may be NULL if password is not encoded by the client.
   6076    * The buffer pointed by the @a password becomes invalid when the pointer
   6077    * to the structure is freed by #MHD_free().
   6078    */
   6079   char *password;
   6080 
   6081   /**
   6082    * The length of the @a password, not including zero-termination;
   6083    * when the @a password is NULL, the length is always zero.
   6084    */
   6085   size_t password_len;
   6086 };
   6087 
   6088 /**
   6089  * Get the username and password from the Basic Authorisation header
   6090  * sent by the client
   6091  *
   6092  * @param connection the MHD connection structure
   6093  * @return NULL if no valid Basic Authentication header is present in
   6094  *         current request, or
   6095  *         pointer to structure with username and password, which must be
   6096  *         freed by #MHD_free().
   6097  * @note Available since #MHD_VERSION 0x00097701
   6098  * @ingroup authentication
   6099  */
   6100 _MHD_EXTERN struct MHD_BasicAuthInfo *
   6101 MHD_basic_auth_get_username_password3 (struct MHD_Connection *connection);
   6102 
   6103 /**
   6104  * Queues a response to request basic authentication from the client.
   6105  *
   6106  * The given response object is expected to include the payload for
   6107  * the response; the "WWW-Authenticate" header will be added and the
   6108  * response queued with the 'UNAUTHORIZED' status code.
   6109  *
   6110  * See RFC 7617#section-2 for details.
   6111  *
   6112  * The @a response is modified by this function. The modified response object
   6113  * can be used to respond subsequent requests by #MHD_queue_response()
   6114  * function with status code #MHD_HTTP_UNAUTHORIZED and must not be used again
   6115  * with MHD_queue_basic_auth_required_response3() function. The response could
   6116  * be destroyed right after call of this function.
   6117  *
   6118  * @param connection the MHD connection structure
   6119  * @param realm the realm presented to the client
   6120  * @param prefer_utf8 if not set to #MHD_NO, parameter'charset="UTF-8"' will
   6121  *                    be added, indicating for client that UTF-8 encoding
   6122  *                    is preferred
   6123  * @param response the response object to modify and queue; the NULL
   6124  *                 is tolerated
   6125  * @return #MHD_YES on success, #MHD_NO otherwise
   6126  * @note Available since #MHD_VERSION 0x00097704
   6127  * @ingroup authentication
   6128  */
   6129 _MHD_EXTERN enum MHD_Result
   6130 MHD_queue_basic_auth_required_response3 (struct MHD_Connection *connection,
   6131                                          const char *realm,
   6132                                          int prefer_utf8,
   6133                                          struct MHD_Response *response);
   6134 
   6135 /**
   6136  * Get the username and password from the basic authorization header sent by the client
   6137  *
   6138  * @param connection The MHD connection structure
   6139  * @param[out] password a pointer for the password, free using #MHD_free().
   6140  * @return NULL if no username could be found, a pointer
   6141  *      to the username if found, free using #MHD_free().
   6142  * @deprecated use #MHD_basic_auth_get_username_password3()
   6143  * @ingroup authentication
   6144  */
   6145 _MHD_EXTERN char *
   6146 MHD_basic_auth_get_username_password (struct MHD_Connection *connection,
   6147                                       char **password);
   6148 
   6149 
   6150 /**
   6151  * Queues a response to request basic authentication from the client
   6152  * The given response object is expected to include the payload for
   6153  * the response; the "WWW-Authenticate" header will be added and the
   6154  * response queued with the 'UNAUTHORIZED' status code.
   6155  *
   6156  * @param connection The MHD connection structure
   6157  * @param realm the realm presented to the client
   6158  * @param response response object to modify and queue; the NULL is tolerated
   6159  * @return #MHD_YES on success, #MHD_NO otherwise
   6160  * @deprecated use MHD_queue_basic_auth_required_response3()
   6161  * @ingroup authentication
   6162  */
   6163 _MHD_EXTERN enum MHD_Result
   6164 MHD_queue_basic_auth_fail_response (struct MHD_Connection *connection,
   6165                                     const char *realm,
   6166                                     struct MHD_Response *response);
   6167 
   6168 /* ********************** generic query functions ********************** */
   6169 
   6170 
   6171 /**
   6172  * Obtain information about the given connection.
   6173  * The returned pointer is invalidated with the next call of this function or
   6174  * when the connection is closed.
   6175  *
   6176  * @param connection what connection to get information about
   6177  * @param info_type what information is desired?
   6178  * @param ... depends on @a info_type
   6179  * @return NULL if this information is not available
   6180  *         (or if the @a info_type is unknown)
   6181  * @ingroup specialized
   6182  */
   6183 _MHD_EXTERN const union MHD_ConnectionInfo *
   6184 MHD_get_connection_info (struct MHD_Connection *connection,
   6185                          enum MHD_ConnectionInfoType info_type,
   6186                          ...);
   6187 
   6188 
   6189 /**
   6190  * MHD connection options.  Given to #MHD_set_connection_option to
   6191  * set custom options for a particular connection.
   6192  */
   6193 enum MHD_CONNECTION_OPTION
   6194 {
   6195 
   6196   /**
   6197    * Set a custom timeout for the given connection.  Specified
   6198    * as the number of seconds, given as an `unsigned int`.  Use
   6199    * zero for no timeout.
   6200    * If timeout was set to zero (or unset) before, setup of new value by
   6201    * MHD_set_connection_option() will reset timeout timer.
   6202    * Values larger than (UINT64_MAX / 2000 - 1) will
   6203    * be clipped to this number.
   6204    */
   6205   MHD_CONNECTION_OPTION_TIMEOUT
   6206 
   6207 } _MHD_FIXED_ENUM;
   6208 
   6209 
   6210 /**
   6211  * Set a custom option for the given connection, overriding defaults.
   6212  *
   6213  * @param connection connection to modify
   6214  * @param option option to set
   6215  * @param ... arguments to the option, depending on the option type
   6216  * @return #MHD_YES on success, #MHD_NO if setting the option failed
   6217  * @ingroup specialized
   6218  */
   6219 _MHD_EXTERN enum MHD_Result
   6220 MHD_set_connection_option (struct MHD_Connection *connection,
   6221                            enum MHD_CONNECTION_OPTION option,
   6222                            ...);
   6223 
   6224 
   6225 /**
   6226  * Information about an MHD daemon.
   6227  */
   6228 union MHD_DaemonInfo
   6229 {
   6230   /**
   6231    * Size of the key, no longer supported.
   6232    * @deprecated
   6233    */
   6234   size_t key_size;
   6235 
   6236   /**
   6237    * Size of the mac key, no longer supported.
   6238    * @deprecated
   6239    */
   6240   size_t mac_key_size;
   6241 
   6242   /**
   6243    * Socket, returned for #MHD_DAEMON_INFO_LISTEN_FD.
   6244    */
   6245   MHD_socket listen_fd;
   6246 
   6247   /**
   6248    * Bind port number, returned for #MHD_DAEMON_INFO_BIND_PORT.
   6249    */
   6250   uint16_t port;
   6251 
   6252   /**
   6253    * epoll FD, returned for #MHD_DAEMON_INFO_EPOLL_FD.
   6254    */
   6255   int epoll_fd;
   6256 
   6257   /**
   6258    * Number of active connections, for #MHD_DAEMON_INFO_CURRENT_CONNECTIONS.
   6259    */
   6260   unsigned int num_connections;
   6261 
   6262   /**
   6263    * Combination of #MHD_FLAG values, for #MHD_DAEMON_INFO_FLAGS.
   6264    * This value is actually a bitfield.
   6265    * Note: flags may differ from original 'flags' specified for
   6266    * daemon, especially if #MHD_USE_AUTO was set.
   6267    */
   6268   enum MHD_FLAG flags;
   6269 };
   6270 
   6271 
   6272 /**
   6273  * Obtain information about the given daemon.
   6274  * The returned pointer is invalidated with the next call of this function or
   6275  * when the daemon is stopped.
   6276  *
   6277  * @param daemon what daemon to get information about
   6278  * @param info_type what information is desired?
   6279  * @param ... depends on @a info_type
   6280  * @return NULL if this information is not available
   6281  *         (or if the @a info_type is unknown)
   6282  * @ingroup specialized
   6283  */
   6284 _MHD_EXTERN const union MHD_DaemonInfo *
   6285 MHD_get_daemon_info (struct MHD_Daemon *daemon,
   6286                      enum MHD_DaemonInfoType info_type,
   6287                      ...);
   6288 
   6289 
   6290 /**
   6291  * Obtain the version of this library
   6292  *
   6293  * @return static version string, e.g. "0.9.9"
   6294  * @ingroup specialized
   6295  */
   6296 _MHD_EXTERN const char *
   6297 MHD_get_version (void);
   6298 
   6299 
   6300 /**
   6301  * Obtain the version of this library as a binary value.
   6302  *
   6303  * @return version binary value, e.g. "0x00090900" (#MHD_VERSION of
   6304  *         compiled MHD binary)
   6305  * @note Available since #MHD_VERSION 0x00097601
   6306  * @ingroup specialized
   6307  */
   6308 _MHD_EXTERN uint32_t
   6309 MHD_get_version_bin (void);
   6310 
   6311 
   6312 /**
   6313  * Types of information about MHD features,
   6314  * used by #MHD_is_feature_supported().
   6315  */
   6316 enum MHD_FEATURE
   6317 {
   6318   /**
   6319    * Get whether messages are supported. If supported then in debug
   6320    * mode messages can be printed to stderr or to external logger.
   6321    */
   6322   MHD_FEATURE_MESSAGES = 1,
   6323 
   6324   /**
   6325    * Get whether HTTPS is supported.  If supported then flag
   6326    * #MHD_USE_TLS and options #MHD_OPTION_HTTPS_MEM_KEY,
   6327    * #MHD_OPTION_HTTPS_MEM_CERT, #MHD_OPTION_HTTPS_MEM_TRUST,
   6328    * #MHD_OPTION_HTTPS_MEM_DHPARAMS, #MHD_OPTION_HTTPS_CRED_TYPE,
   6329    * #MHD_OPTION_HTTPS_PRIORITIES can be used.
   6330    */
   6331   MHD_FEATURE_TLS = 2,
   6332   MHD_FEATURE_SSL = 2,
   6333 
   6334   /**
   6335    * Get whether option #MHD_OPTION_HTTPS_CERT_CALLBACK is
   6336    * supported.
   6337    */
   6338   MHD_FEATURE_HTTPS_CERT_CALLBACK = 3,
   6339 
   6340   /**
   6341    * Get whether IPv6 is supported. If supported then flag
   6342    * #MHD_USE_IPv6 can be used.
   6343    */
   6344   MHD_FEATURE_IPv6 = 4,
   6345 
   6346   /**
   6347    * Get whether IPv6 without IPv4 is supported. If not supported
   6348    * then IPv4 is always enabled in IPv6 sockets and
   6349    * flag #MHD_USE_DUAL_STACK is always used when #MHD_USE_IPv6 is
   6350    * specified.
   6351    */
   6352   MHD_FEATURE_IPv6_ONLY = 5,
   6353 
   6354   /**
   6355    * Get whether `poll()` is supported. If supported then flag
   6356    * #MHD_USE_POLL can be used.
   6357    */
   6358   MHD_FEATURE_POLL = 6,
   6359 
   6360   /**
   6361    * Get whether `epoll()` is supported. If supported then Flags
   6362    * #MHD_USE_EPOLL and
   6363    * #MHD_USE_EPOLL_INTERNAL_THREAD can be used.
   6364    */
   6365   MHD_FEATURE_EPOLL = 7,
   6366 
   6367   /**
   6368    * Get whether shutdown on listen socket to signal other
   6369    * threads is supported. If not supported flag
   6370    * #MHD_USE_ITC is automatically forced.
   6371    */
   6372   MHD_FEATURE_SHUTDOWN_LISTEN_SOCKET = 8,
   6373 
   6374   /**
   6375    * Get whether socketpair is used internally instead of pipe to
   6376    * signal other threads.
   6377    */
   6378   MHD_FEATURE_SOCKETPAIR = 9,
   6379 
   6380   /**
   6381    * Get whether TCP Fast Open is supported. If supported then
   6382    * flag #MHD_USE_TCP_FASTOPEN and option
   6383    * #MHD_OPTION_TCP_FASTOPEN_QUEUE_SIZE can be used.
   6384    */
   6385   MHD_FEATURE_TCP_FASTOPEN = 10,
   6386 
   6387   /**
   6388    * Get whether HTTP Basic authorization is supported. If supported
   6389    * then functions #MHD_basic_auth_get_username_password and
   6390    * #MHD_queue_basic_auth_fail_response can be used.
   6391    */
   6392   MHD_FEATURE_BASIC_AUTH = 11,
   6393 
   6394   /**
   6395    * Get whether HTTP Digest authorization is supported. If
   6396    * supported then options #MHD_OPTION_DIGEST_AUTH_RANDOM,
   6397    * #MHD_OPTION_NONCE_NC_SIZE and
   6398    * #MHD_digest_auth_check() can be used.
   6399    */
   6400   MHD_FEATURE_DIGEST_AUTH = 12,
   6401 
   6402   /**
   6403    * Get whether postprocessor is supported. If supported then
   6404    * functions #MHD_create_post_processor(), #MHD_post_process() and
   6405    * #MHD_destroy_post_processor() can
   6406    * be used.
   6407    */
   6408   MHD_FEATURE_POSTPROCESSOR = 13,
   6409 
   6410   /**
   6411   * Get whether password encrypted private key for HTTPS daemon is
   6412   * supported. If supported then option
   6413   * ::MHD_OPTION_HTTPS_KEY_PASSWORD can be used.
   6414   */
   6415   MHD_FEATURE_HTTPS_KEY_PASSWORD = 14,
   6416 
   6417   /**
   6418    * Get whether reading files beyond 2 GiB boundary is supported.
   6419    * If supported then #MHD_create_response_from_fd(),
   6420    * #MHD_create_response_from_fd64 #MHD_create_response_from_fd_at_offset()
   6421    * and #MHD_create_response_from_fd_at_offset64() can be used with sizes and
   6422    * offsets larger than 2 GiB. If not supported value of size+offset is
   6423    * limited to 2 GiB.
   6424    */
   6425   MHD_FEATURE_LARGE_FILE = 15,
   6426 
   6427   /**
   6428    * Get whether MHD set names on generated threads.
   6429    */
   6430   MHD_FEATURE_THREAD_NAMES = 16,
   6431   MHD_THREAD_NAMES = 16,
   6432 
   6433   /**
   6434    * Get whether HTTP "Upgrade" is supported.
   6435    * If supported then #MHD_ALLOW_UPGRADE, #MHD_upgrade_action() and
   6436    * #MHD_create_response_for_upgrade() can be used.
   6437    */
   6438   MHD_FEATURE_UPGRADE = 17,
   6439 
   6440   /**
   6441    * Get whether it's safe to use same FD for multiple calls of
   6442    * #MHD_create_response_from_fd() and whether it's safe to use single
   6443    * response generated by #MHD_create_response_from_fd() with multiple
   6444    * connections at same time.
   6445    * If #MHD_is_feature_supported() return #MHD_NO for this feature then
   6446    * usage of responses with same file FD in multiple parallel threads may
   6447    * results in incorrect data sent to remote client.
   6448    * It's always safe to use same file FD in multiple responses if MHD
   6449    * is run in any single thread mode.
   6450    */
   6451   MHD_FEATURE_RESPONSES_SHARED_FD = 18,
   6452 
   6453   /**
   6454    * Get whether MHD support automatic detection of bind port number.
   6455    * @sa #MHD_DAEMON_INFO_BIND_PORT
   6456    */
   6457   MHD_FEATURE_AUTODETECT_BIND_PORT = 19,
   6458 
   6459   /**
   6460    * Get whether MHD supports automatic SIGPIPE suppression.
   6461    * If SIGPIPE suppression is not supported, application must handle
   6462    * SIGPIPE signal by itself.
   6463    */
   6464   MHD_FEATURE_AUTOSUPPRESS_SIGPIPE = 20,
   6465 
   6466   /**
   6467    * Get whether MHD use system's sendfile() function to send
   6468    * file-FD based responses over non-TLS connections.
   6469    * @note Since v0.9.56
   6470    */
   6471   MHD_FEATURE_SENDFILE = 21,
   6472 
   6473   /**
   6474    * Get whether MHD supports threads.
   6475    */
   6476   MHD_FEATURE_THREADS = 22,
   6477 
   6478   /**
   6479    * Get whether option #MHD_OPTION_HTTPS_CERT_CALLBACK2 is
   6480    * supported.
   6481    */
   6482   MHD_FEATURE_HTTPS_CERT_CALLBACK2 = 23,
   6483 
   6484   /**
   6485    * Get whether automatic parsing of HTTP Cookie header is supported.
   6486    * If disabled, no MHD_COOKIE_KIND will be generated by MHD.
   6487    * MHD versions before 0x00097701 always support cookie parsing.
   6488    * @note Available since #MHD_VERSION 0x01000200
   6489    */
   6490   MHD_FEATURE_COOKIE_PARSING = 24,
   6491 
   6492   /**
   6493    * Get whether the early version the Digest Authorization (RFC 2069) is
   6494    * supported (digest authorisation without QOP parameter).
   6495    * Since #MHD_VERSION 0x00097701 it is always supported if Digest Auth
   6496    * module is built.
   6497    * @note Available since #MHD_VERSION 0x00097701
   6498    */
   6499   MHD_FEATURE_DIGEST_AUTH_RFC2069 = 25,
   6500 
   6501   /**
   6502    * Get whether the MD5-based hashing algorithms are supported for Digest
   6503    * Authorization.
   6504    * Currently it is always supported if Digest Auth module is built
   6505    * unless manually disabled in a custom build.
   6506    * @note Available since #MHD_VERSION 0x00097701
   6507    */
   6508   MHD_FEATURE_DIGEST_AUTH_MD5 = 26,
   6509 
   6510   /**
   6511    * Get whether the SHA-256-based hashing algorithms are supported for Digest
   6512    * Authorization.
   6513    * It is always supported since #MHD_VERSION 0x00096200 if Digest Auth
   6514    * module is built unless manually disabled in a custom build.
   6515    * @note Available since #MHD_VERSION 0x00097701
   6516    */
   6517   MHD_FEATURE_DIGEST_AUTH_SHA256 = 27,
   6518 
   6519   /**
   6520    * Get whether the SHA-512/256-based hashing algorithms are supported
   6521    * for Digest Authorization.
   6522    * It it always supported since #MHD_VERSION 0x00097701 if Digest Auth
   6523    * module is built unless manually disabled in a custom build.
   6524    * @note Available since #MHD_VERSION 0x00097701
   6525    */
   6526   MHD_FEATURE_DIGEST_AUTH_SHA512_256 = 28,
   6527 
   6528   /**
   6529    * Get whether QOP with value 'auth-int' (authentication with integrity
   6530    * protection) is supported for Digest Authorization.
   6531    * Currently it is always not supported.
   6532    * @note Available since #MHD_VERSION 0x00097701
   6533    */
   6534   MHD_FEATURE_DIGEST_AUTH_AUTH_INT = 29,
   6535 
   6536   /**
   6537    * Get whether 'session' algorithms (like 'MD5-sess') are supported for Digest
   6538    * Authorization.
   6539    * Currently it is always not supported.
   6540    * @note Available since #MHD_VERSION 0x00097701
   6541    */
   6542   MHD_FEATURE_DIGEST_AUTH_ALGO_SESSION = 30,
   6543 
   6544   /**
   6545    * Get whether 'userhash' is supported for Digest Authorization.
   6546    * It is always supported since #MHD_VERSION 0x00097701 if Digest Auth
   6547    * module is built.
   6548    * @note Available since #MHD_VERSION 0x00097701
   6549    */
   6550   MHD_FEATURE_DIGEST_AUTH_USERHASH = 31,
   6551 
   6552   /**
   6553    * Get whether any of hashing algorithms is implemented by external
   6554    * function (like TLS library) and may fail due to external conditions,
   6555    * like "out-of-memory".
   6556    *
   6557    * If result is #MHD_YES then functions which use hash calculations
   6558    * like #MHD_digest_auth_calc_userhash(), #MHD_digest_auth_check3() and others
   6559    * potentially may fail even with valid input because of out-of-memory error
   6560    * or crypto accelerator device failure, however in practice such fails are
   6561    * unlikely.
   6562    * @note Available since #MHD_VERSION 0x00097701
   6563    */
   6564   MHD_FEATURE_EXTERN_HASH = 32,
   6565 
   6566   /**
   6567    * Get whether MHD was built with asserts enabled.
   6568    * For debug builds the error log is always enabled even if #MHD_USE_ERROR_LOG
   6569    * is not specified for daemon.
   6570    * @note Available since #MHD_VERSION 0x00097701
   6571    */
   6572   MHD_FEATURE_DEBUG_BUILD = 33,
   6573 
   6574   /**
   6575    * Get whether MHD was build with support for overridable FD_SETSIZE.
   6576    * This feature should be always available when the relevant platform ability
   6577    * is detected.
   6578    * @sa #MHD_OPTION_APP_FD_SETSIZE
   6579    * @note Available since #MHD_VERSION 0x00097705
   6580    */
   6581   MHD_FEATURE_FLEXIBLE_FD_SETSIZE = 34
   6582 };
   6583 
   6584 #define MHD_FEATURE_HTTPS_COOKIE_PARSING _MHD_DEPR_IN_MACRO ( \
   6585           "Value MHD_FEATURE_HTTPS_COOKIE_PARSING is deprecated, use MHD_FEATURE_COOKIE_PARSING" \
   6586           ) MHD_FEATURE_COOKIE_PARSING
   6587 
   6588 /**
   6589  * Get information about supported MHD features.
   6590  * Indicate that MHD was compiled with or without support for
   6591  * particular feature. Some features require additional support
   6592  * by kernel. Kernel support is not checked by this function.
   6593  *
   6594  * @param feature type of requested information
   6595  * @return #MHD_YES if feature is supported by MHD, #MHD_NO if
   6596  * feature is not supported or feature is unknown.
   6597  * @ingroup specialized
   6598  */
   6599 _MHD_EXTERN enum MHD_Result
   6600 MHD_is_feature_supported (enum MHD_FEATURE feature);
   6601 
   6602 
   6603 MHD_C_DECLRATIONS_FINISH_HERE_
   6604 
   6605 #endif