gnunet-android

bio.h (41354B)

---

 // Copyright 1995-2016 The OpenSSL Project Authors. All Rights Reserved.
 //
 // Licensed under the Apache License, Version 2.0 (the "License");
 // you may not use this file except in compliance with the License.
 // You may obtain a copy of the License at
 //
 //     https://www.apache.org/licenses/LICENSE-2.0
 //
 // Unless required by applicable law or agreed to in writing, software
 // distributed under the License is distributed on an "AS IS" BASIS,
 // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
 #ifndef OPENSSL_HEADER_BIO_H
 #define OPENSSL_HEADER_BIO_H
 
 #include <openssl/base.h>   // IWYU pragma: export
 
 #include <stdio.h>  // For FILE
 
 #include <openssl/buffer.h>
 #include <openssl/err.h>  // for ERR_print_errors_fp
 #include <openssl/ex_data.h>
 #include <openssl/stack.h>
 
 #if defined(__cplusplus)
 extern "C" {
 #endif
 
 
 // BIO abstracts over a file-descriptor like interface.
 
 
 // Allocation and freeing.
 
 DEFINE_STACK_OF(BIO)
 
 // BIO_new creates a new BIO with the given method and a reference count of one.
 // It returns the fresh |BIO|, or NULL on error.
 OPENSSL_EXPORT BIO *BIO_new(const BIO_METHOD *method);
 
 // BIO_free decrements the reference count of |bio|. If the reference count
 // drops to zero, it calls the destroy callback, if present, on the method and
 // frees |bio| itself. It then repeats that for the next BIO in the chain, if
 // any.
 //
 // It returns one on success or zero otherwise.
 OPENSSL_EXPORT int BIO_free(BIO *bio);
 
 // BIO_vfree performs the same actions as |BIO_free|, but has a void return
 // value. This is provided for API-compat.
 //
 // TODO(fork): remove.
 OPENSSL_EXPORT void BIO_vfree(BIO *bio);
 
 // BIO_up_ref increments the reference count of |bio| and returns one.
 OPENSSL_EXPORT int BIO_up_ref(BIO *bio);
 
 
 // Basic I/O.
 
 // BIO_read attempts to read |len| bytes into |data|. It returns the number of
 // bytes read, zero on EOF, or a negative number on error.
 OPENSSL_EXPORT int BIO_read(BIO *bio, void *data, int len);
 
 // BIO_gets reads a line from |bio| and writes at most |size| bytes into |buf|.
 // It returns the number of bytes read or a negative number on error. This
 // function's output always includes a trailing NUL byte, so it will read at
 // most |size - 1| bytes.
 //
 // If the function read a complete line, the output will include the newline
 // character, '\n'. If no newline was found before |size - 1| bytes or EOF, it
 // outputs the bytes which were available.
 OPENSSL_EXPORT int BIO_gets(BIO *bio, char *buf, int size);
 
 // BIO_write writes |len| bytes from |data| to |bio|. It returns the number of
 // bytes written or a negative number on error.
 OPENSSL_EXPORT int BIO_write(BIO *bio, const void *data, int len);
 
 // BIO_write_all writes |len| bytes from |data| to |bio|, looping as necessary.
 // It returns one if all bytes were successfully written and zero on error.
 OPENSSL_EXPORT int BIO_write_all(BIO *bio, const void *data, size_t len);
 
 // BIO_puts writes a NUL terminated string from |buf| to |bio|. It returns the
 // number of bytes written or a negative number on error.
 OPENSSL_EXPORT int BIO_puts(BIO *bio, const char *buf);
 
 // BIO_flush flushes any buffered output. It returns one on success and zero
 // otherwise.
 OPENSSL_EXPORT int BIO_flush(BIO *bio);
 
 
 // Low-level control functions.
 //
 // These are generic functions for sending control requests to a BIO. In
 // general one should use the wrapper functions like |BIO_get_close|.
 
 // BIO_ctrl sends the control request |cmd| to |bio|. The |cmd| argument should
 // be one of the |BIO_C_*| values.
 OPENSSL_EXPORT long BIO_ctrl(BIO *bio, int cmd, long larg, void *parg);
 
 // BIO_ptr_ctrl acts like |BIO_ctrl| but passes the address of a |void*|
 // pointer as |parg| and returns the value that is written to it, or NULL if
 // the control request returns <= 0.
 OPENSSL_EXPORT char *BIO_ptr_ctrl(BIO *bp, int cmd, long larg);
 
 // BIO_int_ctrl acts like |BIO_ctrl| but passes the address of a copy of |iarg|
 // as |parg|.
 OPENSSL_EXPORT long BIO_int_ctrl(BIO *bp, int cmd, long larg, int iarg);
 
 // BIO_reset resets |bio| to its initial state, the precise meaning of which
 // depends on the concrete type of |bio|. It returns one on success and zero
 // otherwise.
 OPENSSL_EXPORT int BIO_reset(BIO *bio);
 
 // BIO_eof returns non-zero when |bio| has reached end-of-file. The precise
 // meaning of which depends on the concrete type of |bio|. Note that in the
 // case of BIO_pair this always returns non-zero.
 OPENSSL_EXPORT int BIO_eof(BIO *bio);
 
 // BIO_set_flags ORs |flags| with |bio->flags|.
 OPENSSL_EXPORT void BIO_set_flags(BIO *bio, int flags);
 
 // BIO_clear_flags ANDs |bio->flags| with the bitwise-complement of |flags|.
 OPENSSL_EXPORT void BIO_clear_flags(BIO *bio, int flags);
 
 // BIO_test_flags returns |bio->flags| AND |flags|.
 OPENSSL_EXPORT int BIO_test_flags(const BIO *bio, int flags);
 
 // BIO_should_read returns non-zero if |bio| encountered a temporary error
 // while reading (i.e. EAGAIN), indicating that the caller should retry the
 // read.
 OPENSSL_EXPORT int BIO_should_read(const BIO *bio);
 
 // BIO_should_write returns non-zero if |bio| encountered a temporary error
 // while writing (i.e. EAGAIN), indicating that the caller should retry the
 // write.
 OPENSSL_EXPORT int BIO_should_write(const BIO *bio);
 
 // BIO_should_retry returns non-zero if the reason that caused a failed I/O
 // operation is temporary and thus the operation should be retried. Otherwise,
 // it was a permanent error and it returns zero.
 OPENSSL_EXPORT int BIO_should_retry(const BIO *bio);
 
 // BIO_should_io_special returns non-zero if |bio| encountered a temporary
 // error while performing a special I/O operation, indicating that the caller
 // should retry. The operation that caused the error is returned by
 // |BIO_get_retry_reason|.
 OPENSSL_EXPORT int BIO_should_io_special(const BIO *bio);
 
 // BIO_RR_CONNECT indicates that a connect would have blocked
 #define BIO_RR_CONNECT 0x02
 
 // BIO_RR_ACCEPT indicates that an accept would have blocked
 #define BIO_RR_ACCEPT 0x03
 
 // BIO_get_retry_reason returns the special I/O operation that needs to be
 // retried. The return value is one of the |BIO_RR_*| values.
 OPENSSL_EXPORT int BIO_get_retry_reason(const BIO *bio);
 
 // BIO_set_retry_reason sets the special I/O operation that needs to be retried
 // to |reason|, which should be one of the |BIO_RR_*| values.
 OPENSSL_EXPORT void BIO_set_retry_reason(BIO *bio, int reason);
 
 // BIO_set_retry_read sets the |BIO_FLAGS_READ| and |BIO_FLAGS_SHOULD_RETRY|
 // flags on |bio|.
 OPENSSL_EXPORT void BIO_set_retry_read(BIO *bio);
 
 // BIO_set_retry_write sets the |BIO_FLAGS_WRITE| and |BIO_FLAGS_SHOULD_RETRY|
 // flags on |bio|.
 OPENSSL_EXPORT void BIO_set_retry_write(BIO *bio);
 
 // BIO_get_retry_flags gets the |BIO_FLAGS_READ|, |BIO_FLAGS_WRITE|,
 // |BIO_FLAGS_IO_SPECIAL| and |BIO_FLAGS_SHOULD_RETRY| flags from |bio|.
 OPENSSL_EXPORT int BIO_get_retry_flags(BIO *bio);
 
 // BIO_clear_retry_flags clears the |BIO_FLAGS_READ|, |BIO_FLAGS_WRITE|,
 // |BIO_FLAGS_IO_SPECIAL| and |BIO_FLAGS_SHOULD_RETRY| flags from |bio|.
 OPENSSL_EXPORT void BIO_clear_retry_flags(BIO *bio);
 
 // BIO_method_type returns the type of |bio|, which is one of the |BIO_TYPE_*|
 // values.
 OPENSSL_EXPORT int BIO_method_type(const BIO *bio);
 
 typedef int BIO_info_cb(BIO *, int, int);
 
 // BIO_callback_ctrl allows the callback function to be manipulated. The |cmd|
 // arg will generally be |BIO_CTRL_SET_CALLBACK| but arbitrary command values
 // can be interpreted by the |BIO|.
 OPENSSL_EXPORT long BIO_callback_ctrl(BIO *bio, int cmd, BIO_info_cb *fp);
 
 // BIO_pending returns the number of bytes pending to be read.
 OPENSSL_EXPORT size_t BIO_pending(const BIO *bio);
 
 // BIO_ctrl_pending calls |BIO_pending| and exists only for compatibility with
 // OpenSSL.
 OPENSSL_EXPORT size_t BIO_ctrl_pending(const BIO *bio);
 
 // BIO_wpending returns the number of bytes pending to be written.
 OPENSSL_EXPORT size_t BIO_wpending(const BIO *bio);
 
 // BIO_set_close sets the close flag for |bio|. The meaning of which depends on
 // the type of |bio| but, for example, a memory BIO interprets the close flag
 // as meaning that it owns its buffer. It returns one on success and zero
 // otherwise.
 OPENSSL_EXPORT int BIO_set_close(BIO *bio, int close_flag);
 
 // BIO_number_read returns the number of bytes that have been read from
 // |bio|.
 OPENSSL_EXPORT uint64_t BIO_number_read(const BIO *bio);
 
 // BIO_number_written returns the number of bytes that have been written to
 // |bio|.
 OPENSSL_EXPORT uint64_t BIO_number_written(const BIO *bio);
 
 
 // Managing chains of BIOs.
 //
 // BIOs can be put into chains where the output of one is used as the input of
 // the next etc. The most common case is a buffering BIO, which accepts and
 // buffers writes until flushed into the next BIO in the chain.
 
 // BIO_push adds |appended_bio| to the end of the chain with |bio| at the head.
 // It returns |bio|. Note that |appended_bio| may be the head of a chain itself
 // and thus this function can be used to join two chains.
 //
 // BIO_push takes ownership of the caller's reference to |appended_bio|.
 OPENSSL_EXPORT BIO *BIO_push(BIO *bio, BIO *appended_bio);
 
 // BIO_pop removes |bio| from the head of a chain and returns the next BIO in
 // the chain, or NULL if there is no next BIO.
 //
 // The caller takes ownership of the chain's reference to |bio|.
 OPENSSL_EXPORT BIO *BIO_pop(BIO *bio);
 
 // BIO_next returns the next BIO in the chain after |bio|, or NULL if there is
 // no such BIO.
 OPENSSL_EXPORT BIO *BIO_next(BIO *bio);
 
 // BIO_free_all calls |BIO_free|.
 //
 // TODO(fork): update callers and remove.
 OPENSSL_EXPORT void BIO_free_all(BIO *bio);
 
 // BIO_find_type walks a chain of BIOs and returns the first that matches
 // |type|, which is one of the |BIO_TYPE_*| values.
 OPENSSL_EXPORT BIO *BIO_find_type(BIO *bio, int type);
 
 // BIO_copy_next_retry sets the retry flags and |retry_reason| of |bio| from
 // the next BIO in the chain.
 OPENSSL_EXPORT void BIO_copy_next_retry(BIO *bio);
 
 
 // Printf functions.
 
 // BIO_printf behaves like |printf| but outputs to |bio| rather than a |FILE|.
 // It returns the number of bytes written or a negative number on error.
 OPENSSL_EXPORT int BIO_printf(BIO *bio, const char *format, ...)
     OPENSSL_PRINTF_FORMAT_FUNC(2, 3);
 
 
 // Utility functions.
 
 // BIO_indent prints min(|indent|, |max_indent|) spaces. It returns one on
 // success and zero otherwise.
 OPENSSL_EXPORT int BIO_indent(BIO *bio, unsigned indent, unsigned max_indent);
 
 // BIO_hexdump writes a hex dump of |data| to |bio|. Each line will be indented
 // by |indent| spaces. It returns one on success and zero otherwise.
 OPENSSL_EXPORT int BIO_hexdump(BIO *bio, const uint8_t *data, size_t len,
                                unsigned indent);
 
 // ERR_print_errors prints the current contents of the error stack to |bio|
 // using human readable strings where possible.
 OPENSSL_EXPORT void ERR_print_errors(BIO *bio);
 
 // BIO_read_asn1 reads a single ASN.1 object from |bio|. If successful it sets
 // |*out| to be an allocated buffer (that should be freed with |OPENSSL_free|),
 // |*out_size| to the length, in bytes, of that buffer and returns one.
 // Otherwise it returns zero.
 //
 // If the length of the object is greater than |max_len| or 2^32 then the
 // function will fail. Long-form tags are not supported. If the length of the
 // object is indefinite the full contents of |bio| are read, unless it would be
 // greater than |max_len|, in which case the function fails.
 //
 // If the function fails then some unknown amount of data may have been read
 // from |bio|.
 OPENSSL_EXPORT int BIO_read_asn1(BIO *bio, uint8_t **out, size_t *out_len,
                                  size_t max_len);
 
 
 // Memory BIOs.
 //
 // Memory BIOs can be used as a read-only source (with |BIO_new_mem_buf|) or a
 // writable sink (with |BIO_new|, |BIO_s_mem| and |BIO_mem_contents|). Data
 // written to a writable, memory BIO can be recalled by reading from it.
 //
 // Calling |BIO_reset| on a read-only BIO resets it to the original contents.
 // On a writable BIO, it clears any data.
 //
 // If the close flag is set to |BIO_NOCLOSE| (not the default) then the
 // underlying |BUF_MEM| will not be freed when the |BIO| is freed.
 //
 // Memory BIOs support |BIO_gets| and |BIO_puts|.
 //
 // |BIO_ctrl_pending| returns the number of bytes currently stored.
 
 // BIO_NOCLOSE and |BIO_CLOSE| can be used as symbolic arguments when a "close
 // flag" is passed to a BIO function.
 #define BIO_NOCLOSE 0
 #define BIO_CLOSE 1
 
 // BIO_s_mem returns a |BIO_METHOD| that uses a in-memory buffer.
 OPENSSL_EXPORT const BIO_METHOD *BIO_s_mem(void);
 
 // BIO_new_mem_buf creates read-only BIO that reads from |len| bytes at |buf|.
 // It returns the BIO or NULL on error. This function does not copy or take
 // ownership of |buf|. The caller must ensure the memory pointed to by |buf|
 // outlives the |BIO|.
 //
 // If |len| is negative, then |buf| is treated as a NUL-terminated string, but
 // don't depend on this in new code.
 OPENSSL_EXPORT BIO *BIO_new_mem_buf(const void *buf, ossl_ssize_t len);
 
 // BIO_mem_contents sets |*out_contents| to point to the current contents of
 // |bio| and |*out_len| to contain the length of that data. It returns one on
 // success and zero otherwise.
 OPENSSL_EXPORT int BIO_mem_contents(const BIO *bio,
                                     const uint8_t **out_contents,
                                     size_t *out_len);
 
 // BIO_get_mem_data sets |*contents| to point to the current contents of |bio|
 // and returns the length of the data.
 //
 // WARNING: don't use this, use |BIO_mem_contents|. A return value of zero from
 // this function can mean either that it failed or that the memory buffer is
 // empty.
 OPENSSL_EXPORT long BIO_get_mem_data(BIO *bio, char **contents);
 
 // BIO_get_mem_ptr sets |*out| to a BUF_MEM containing the current contents of
 // |bio|. It returns one on success or zero on error.
 OPENSSL_EXPORT int BIO_get_mem_ptr(BIO *bio, BUF_MEM **out);
 
 // BIO_set_mem_buf sets |b| as the contents of |bio|. If |take_ownership| is
 // non-zero, then |b| will be freed when |bio| is closed. Returns one on
 // success or zero otherwise.
 OPENSSL_EXPORT int BIO_set_mem_buf(BIO *bio, BUF_MEM *b, int take_ownership);
 
 // BIO_set_mem_eof_return sets the value that will be returned from reading
 // |bio| when empty. If |eof_value| is zero then an empty memory BIO will
 // return EOF (that is it will return zero and |BIO_should_retry| will be
 // false). If |eof_value| is non zero then it will return |eof_value| when it
 // is empty and it will set the read retry flag (that is |BIO_read_retry| is
 // true). To avoid ambiguity with a normal positive return value, |eof_value|
 // should be set to a negative value, typically -1.
 //
 // For a read-only BIO, the default is zero (EOF). For a writable BIO, the
 // default is -1 so that additional data can be written once exhausted.
 OPENSSL_EXPORT int BIO_set_mem_eof_return(BIO *bio, int eof_value);
 
 
 // File descriptor BIOs.
 //
 // File descriptor BIOs are wrappers around the system's |read| and |write|
 // functions. If the close flag is set then then |close| is called on the
 // underlying file descriptor when the BIO is freed.
 //
 // |BIO_reset| attempts to seek the file pointer to the start of file using
 // |lseek|.
 
 #if !defined(OPENSSL_NO_POSIX_IO)
 // BIO_s_fd returns a |BIO_METHOD| for file descriptor fds.
 OPENSSL_EXPORT const BIO_METHOD *BIO_s_fd(void);
 
 // BIO_new_fd creates a new file descriptor BIO wrapping |fd|. If |close_flag|
 // is non-zero, then |fd| will be closed when the BIO is.
 OPENSSL_EXPORT BIO *BIO_new_fd(int fd, int close_flag);
 #endif
 
 // BIO_set_fd sets the file descriptor of |bio| to |fd|. If |close_flag| is
 // non-zero then |fd| will be closed when |bio| is. It returns one on success
 // or zero on error.
 //
 // This function may also be used with socket BIOs (see |BIO_s_socket| and
 // |BIO_new_socket|).
 OPENSSL_EXPORT int BIO_set_fd(BIO *bio, int fd, int close_flag);
 
 // BIO_get_fd returns the file descriptor currently in use by |bio| or -1 if
 // |bio| does not wrap a file descriptor. If there is a file descriptor and
 // |out_fd| is not NULL, it also sets |*out_fd| to the file descriptor.
 //
 // This function may also be used with socket BIOs (see |BIO_s_socket| and
 // |BIO_new_socket|).
 OPENSSL_EXPORT int BIO_get_fd(BIO *bio, int *out_fd);
 
 
 // File BIOs.
 //
 // File BIOs are wrappers around a C |FILE| object.
 //
 // |BIO_flush| on a file BIO calls |fflush| on the wrapped stream.
 //
 // |BIO_reset| attempts to seek the file pointer to the start of file using
 // |fseek|.
 //
 // Setting the close flag causes |fclose| to be called on the stream when the
 // BIO is freed.
 
 // BIO_s_file returns a BIO_METHOD that wraps a |FILE|.
 OPENSSL_EXPORT const BIO_METHOD *BIO_s_file(void);
 
 // BIO_new_file creates a file BIO by opening |filename| with the given mode.
 // See the |fopen| manual page for details of the mode argument. On Windows,
 // files may be opened in either binary or text mode so, as in |fopen|, callers
 // must specify the desired option in |mode|.
 OPENSSL_EXPORT BIO *BIO_new_file(const char *filename, const char *mode);
 
 // BIO_FP_TEXT indicates the |FILE| should be switched to text mode on Windows.
 // It has no effect on non-Windows platforms.
 #define BIO_FP_TEXT 0x10
 
 // BIO_new_fp creates a new file BIO that wraps |file|. If |flags| contains
 // |BIO_CLOSE|, then |fclose| will be called on |file| when the BIO is closed.
 //
 // On Windows, if |flags| contains |BIO_FP_TEXT|, this function will
 // additionally switch |file| to text mode. This is not recommended, but may be
 // required for OpenSSL compatibility. If |file| was not already in text mode,
 // mode changes can cause unflushed data in |file| to be written in unexpected
 // ways. See |_setmode| in Windows documentation for details.
 //
 // Unlike OpenSSL, if |flags| does not contain |BIO_FP_TEXT|, the translation
 // mode of |file| is left as-is. In OpenSSL, |file| will be set to binary, with
 // the same pitfalls as above. BoringSSL does not do this so that wrapping a
 // |FILE| in a |BIO| will not inadvertently change its state.
 //
 // To avoid these pitfalls, callers should set the desired translation mode when
 // opening the file. If targeting just BoringSSL, this is sufficient. If
 // targeting both OpenSSL and BoringSSL, callers should set |BIO_FP_TEXT| to
 // match the desired state of the file.
 OPENSSL_EXPORT BIO *BIO_new_fp(FILE *file, int flags);
 
 // BIO_get_fp sets |*out_file| to the current |FILE| for |bio|. It returns one
 // on success and zero otherwise.
 OPENSSL_EXPORT int BIO_get_fp(BIO *bio, FILE **out_file);
 
 // BIO_set_fp sets the |FILE| for |bio|. If |flags| contains |BIO_CLOSE| then
 // |fclose| will be called on |file| when |bio| is closed. It returns one on
 // success and zero otherwise.
 //
 // On Windows, if |flags| contains |BIO_FP_TEXT|, this function will
 // additionally switch |file| to text mode. This is not recommended, but may be
 // required for OpenSSL compatibility. If |file| was not already in text mode,
 // mode changes can cause unflushed data in |file| to be written in unexpected
 // ways. See |_setmode| in Windows documentation for details.
 //
 // Unlike OpenSSL, if |flags| does not contain |BIO_FP_TEXT|, the translation
 // mode of |file| is left as-is. In OpenSSL, |file| will be set to binary, with
 // the same pitfalls as above. BoringSSL does not do this so that wrapping a
 // |FILE| in a |BIO| will not inadvertently change its state.
 //
 // To avoid these pitfalls, callers should set the desired translation mode when
 // opening the file. If targeting just BoringSSL, this is sufficient. If
 // targeting both OpenSSL and BoringSSL, callers should set |BIO_FP_TEXT| to
 // match the desired state of the file.
 OPENSSL_EXPORT int BIO_set_fp(BIO *bio, FILE *file, int flags);
 
 // BIO_read_filename opens |filename| for reading and sets the result as the
 // |FILE| for |bio|. It returns one on success and zero otherwise. The |FILE|
 // will be closed when |bio| is freed. On Windows, the file is opened in binary
 // mode.
 OPENSSL_EXPORT int BIO_read_filename(BIO *bio, const char *filename);
 
 // BIO_write_filename opens |filename| for writing and sets the result as the
 // |FILE| for |bio|. It returns one on success and zero otherwise. The |FILE|
 // will be closed when |bio| is freed. On Windows, the file is opened in binary
 // mode.
 OPENSSL_EXPORT int BIO_write_filename(BIO *bio, const char *filename);
 
 // BIO_append_filename opens |filename| for appending and sets the result as
 // the |FILE| for |bio|. It returns one on success and zero otherwise. The
 // |FILE| will be closed when |bio| is freed. On Windows, the file is opened in
 // binary mode.
 OPENSSL_EXPORT int BIO_append_filename(BIO *bio, const char *filename);
 
 // BIO_rw_filename opens |filename| for reading and writing and sets the result
 // as the |FILE| for |bio|. It returns one on success and zero otherwise. The
 // |FILE| will be closed when |bio| is freed. On Windows, the file is opened in
 // binary mode.
 OPENSSL_EXPORT int BIO_rw_filename(BIO *bio, const char *filename);
 
 // BIO_tell returns the file offset of |bio|, or a negative number on error or
 // if |bio| does not support the operation.
 //
 // TODO(https://crbug.com/boringssl/465): On platforms where |long| is 32-bit,
 // this function cannot report 64-bit offsets.
 OPENSSL_EXPORT long BIO_tell(BIO *bio);
 
 // BIO_seek sets the file offset of |bio| to |offset|. It returns a non-negative
 // number on success and a negative number on error. If |bio| is a file
 // descriptor |BIO|, it returns the resulting file offset on success. If |bio|
 // is a file |BIO|, it returns zero on success.
 //
 // WARNING: This function's return value conventions differs from most functions
 // in this library.
 //
 // TODO(https://crbug.com/boringssl/465): On platforms where |long| is 32-bit,
 // this function cannot handle 64-bit offsets.
 OPENSSL_EXPORT long BIO_seek(BIO *bio, long offset);
 
 
 // Socket BIOs.
 //
 // Socket BIOs behave like file descriptor BIOs but, on Windows systems, wrap
 // the system's |recv| and |send| functions instead of |read| and |write|. On
 // Windows, file descriptors are provided by C runtime and are not
 // interchangeable with sockets.
 //
 // Socket BIOs may be used with |BIO_set_fd| and |BIO_get_fd|.
 //
 // TODO(davidben): Add separate APIs and fix the internals to use |SOCKET|s
 // around rather than rely on int casts.
 
 #if !defined(OPENSSL_NO_SOCK)
 OPENSSL_EXPORT const BIO_METHOD *BIO_s_socket(void);
 
 // BIO_new_socket allocates and initialises a fresh BIO which will read and
 // write to the socket |fd|. If |close_flag| is |BIO_CLOSE| then closing the
 // BIO will close |fd|. It returns the fresh |BIO| or NULL on error.
 OPENSSL_EXPORT BIO *BIO_new_socket(int fd, int close_flag);
 #endif  // !OPENSSL_NO_SOCK
 
 
 // Connect BIOs.
 //
 // A connection BIO creates a network connection and transfers data over the
 // resulting socket.
 
 #if !defined(OPENSSL_NO_SOCK)
 OPENSSL_EXPORT const BIO_METHOD *BIO_s_connect(void);
 
 // BIO_new_connect returns a BIO that connects to the given hostname and port.
 // The |host_and_optional_port| argument should be of the form
 // "www.example.com" or "www.example.com:443". If the port is omitted, it must
 // be provided with |BIO_set_conn_port|.
 //
 // It returns the new BIO on success, or NULL on error.
 OPENSSL_EXPORT BIO *BIO_new_connect(const char *host_and_optional_port);
 
 // BIO_set_conn_hostname sets |host_and_optional_port| as the hostname and
 // optional port that |bio| will connect to. If the port is omitted, it must be
 // provided with |BIO_set_conn_port|.
 //
 // It returns one on success and zero otherwise.
 OPENSSL_EXPORT int BIO_set_conn_hostname(BIO *bio,
                                          const char *host_and_optional_port);
 
 // BIO_set_conn_port sets |port_str| as the port or service name that |bio|
 // will connect to. It returns one on success and zero otherwise.
 OPENSSL_EXPORT int BIO_set_conn_port(BIO *bio, const char *port_str);
 
 // BIO_set_conn_int_port sets |*port| as the port that |bio| will connect to.
 // It returns one on success and zero otherwise.
 OPENSSL_EXPORT int BIO_set_conn_int_port(BIO *bio, const int *port);
 
 // BIO_set_nbio sets whether |bio| will use non-blocking I/O operations. It
 // returns one on success and zero otherwise. This only works for connect BIOs
 // and must be called before |bio| is connected to take effect.
 //
 // For socket and fd BIOs, callers must configure blocking vs. non-blocking I/O
 // using the underlying platform APIs.
 OPENSSL_EXPORT int BIO_set_nbio(BIO *bio, int on);
 
 // BIO_do_connect connects |bio| if it has not been connected yet. It returns
 // one on success and <= 0 otherwise.
 OPENSSL_EXPORT int BIO_do_connect(BIO *bio);
 #endif  // !OPENSSL_NO_SOCK
 
 
 // Datagram BIOs.
 //
 // TODO(fork): not implemented.
 
 #define BIO_CTRL_DGRAM_QUERY_MTU 40  // as kernel for current MTU
 
 #define BIO_CTRL_DGRAM_SET_MTU 42 /* set cached value for  MTU. want to use
                                      this if asking the kernel fails */
 
 #define BIO_CTRL_DGRAM_MTU_EXCEEDED 43 /* check whether the MTU was exceed in
                                           the previous write operation. */
 
 // BIO_CTRL_DGRAM_SET_NEXT_TIMEOUT is unsupported as it is unused by consumers
 // and depends on |timeval|, which is not 2038-clean on all platforms.
 
 #define BIO_CTRL_DGRAM_GET_PEER           46
 
 #define BIO_CTRL_DGRAM_GET_FALLBACK_MTU   47
 
 
 // BIO Pairs.
 //
 // BIO pairs provide a "loopback" like system: a pair of BIOs where data
 // written to one can be read from the other and vice versa.
 
 // BIO_new_bio_pair sets |*out1| and |*out2| to two freshly created BIOs where
 // data written to one can be read from the other and vice versa. The
 // |writebuf1| argument gives the size of the buffer used in |*out1| and
 // |writebuf2| for |*out2|. It returns one on success and zero on error.
 OPENSSL_EXPORT int BIO_new_bio_pair(BIO **out1, size_t writebuf1, BIO **out2,
                                     size_t writebuf2);
 
 // BIO_ctrl_get_read_request returns the number of bytes that the other side of
 // |bio| tried (unsuccessfully) to read.
 OPENSSL_EXPORT size_t BIO_ctrl_get_read_request(BIO *bio);
 
 // BIO_ctrl_get_write_guarantee returns the number of bytes that |bio| (which
 // must have been returned by |BIO_new_bio_pair|) will accept on the next
 // |BIO_write| call.
 OPENSSL_EXPORT size_t BIO_ctrl_get_write_guarantee(BIO *bio);
 
 // BIO_shutdown_wr marks |bio| as closed, from the point of view of the other
 // side of the pair. Future |BIO_write| calls on |bio| will fail. It returns
 // one on success and zero otherwise.
 OPENSSL_EXPORT int BIO_shutdown_wr(BIO *bio);
 
 
 // Custom BIOs.
 //
 // Consumers can create custom |BIO|s by filling in a |BIO_METHOD| and using
 // low-level control functions to set state.
 
 // BIO_get_new_index returns a new "type" value for a custom |BIO|.
 OPENSSL_EXPORT int BIO_get_new_index(void);
 
 // BIO_meth_new returns a newly-allocated |BIO_METHOD| or NULL on allocation
 // error. The |type| specifies the type that will be returned by
 // |BIO_method_type|. If this is unnecessary, this value may be zero. The |name|
 // parameter is vestigial and may be NULL.
 //
 // Use the |BIO_meth_set_*| functions below to initialize the |BIO_METHOD|. The
 // function implementations may use |BIO_set_data| and |BIO_get_data| to add
 // method-specific state to associated |BIO|s. Additionally, |BIO_set_init| must
 // be called after an associated |BIO| is fully initialized. State set via
 // |BIO_set_data| may be released by configuring a destructor with
 // |BIO_meth_set_destroy|.
 OPENSSL_EXPORT BIO_METHOD *BIO_meth_new(int type, const char *name);
 
 // BIO_meth_free releases memory associated with |method|.
 OPENSSL_EXPORT void BIO_meth_free(BIO_METHOD *method);
 
 // BIO_meth_set_create sets a function to be called on |BIO_new| for |method|
 // and returns one. The function should return one on success and zero on
 // error.
 OPENSSL_EXPORT int BIO_meth_set_create(BIO_METHOD *method,
                                        int (*create_func)(BIO *));
 
 // BIO_meth_set_destroy sets a function to release data associated with a |BIO|
 // and returns one. The function's return value is ignored.
 //
 // As the |BIO| is about to be destroyed, it is not necessary for |destroy_func|
 // to clear the BIO's state with |BIO_set_data| or |BIO_set_init|. There is no
 // harm in clearing them, but the |BIO| will not be passed to |BIO| operations,
 // unless |destroy_func| itself does so.
 OPENSSL_EXPORT int BIO_meth_set_destroy(BIO_METHOD *method,
                                         int (*destroy_func)(BIO *));
 
 // BIO_meth_set_write sets the implementation of |BIO_write| for |method| and
 // returns one. |BIO_METHOD|s which implement |BIO_write| should also implement
 // |BIO_CTRL_FLUSH|. (See |BIO_meth_set_ctrl|.)
 OPENSSL_EXPORT int BIO_meth_set_write(BIO_METHOD *method,
                                       int (*write_func)(BIO *, const char *,
                                                         int));
 
 // BIO_meth_set_read sets the implementation of |BIO_read| for |method| and
 // returns one.
 OPENSSL_EXPORT int BIO_meth_set_read(BIO_METHOD *method,
                                      int (*read_func)(BIO *, char *, int));
 
 // BIO_meth_set_gets sets the implementation of |BIO_gets| for |method| and
 // returns one.
 OPENSSL_EXPORT int BIO_meth_set_gets(BIO_METHOD *method,
                                      int (*gets_func)(BIO *, char *, int));
 
 // BIO_meth_set_ctrl sets the implementation of |BIO_ctrl| for |method| and
 // returns one.
 OPENSSL_EXPORT int BIO_meth_set_ctrl(BIO_METHOD *method,
                                      long (*ctrl_func)(BIO *, int, long,
                                                        void *));
 
 // BIO_meth_set_callback_ctrl sets the implementation of |BIO_callback_ctrl| for
 // |method| and returns one.
 OPENSSL_EXPORT int BIO_meth_set_callback_ctrl(
     BIO_METHOD *method, long (*callback_ctrl_func)(BIO *, int, BIO_info_cb *));
 
 // BIO_set_data sets custom data on |bio|. It may be retried with
 // |BIO_get_data|.
 //
 // This function should only be called by the implementation of a custom |BIO|.
 // In particular, the data pointer of a built-in |BIO| is private to the
 // library. For other uses, see |BIO_set_ex_data| and |BIO_set_app_data|.
 OPENSSL_EXPORT void BIO_set_data(BIO *bio, void *ptr);
 
 // BIO_get_data returns custom data on |bio| set by |BIO_get_data|.
 //
 // This function should only be called by the implementation of a custom |BIO|.
 // In particular, the data pointer of a built-in |BIO| is private to the
 // library. For other uses, see |BIO_get_ex_data| and |BIO_get_app_data|.
 OPENSSL_EXPORT void *BIO_get_data(BIO *bio);
 
 // BIO_set_init sets whether |bio| has been fully initialized. Until fully
 // initialized, |BIO_read| and |BIO_write| will fail.
 OPENSSL_EXPORT void BIO_set_init(BIO *bio, int init);
 
 // BIO_get_init returns whether |bio| has been fully initialized.
 OPENSSL_EXPORT int BIO_get_init(BIO *bio);
 
 // These are values of the |cmd| argument to |BIO_ctrl|.
 
 // BIO_CTRL_RESET implements |BIO_reset|. The arguments are unused.
 #define BIO_CTRL_RESET 1
 
 // BIO_CTRL_EOF implements |BIO_eof|. The arguments are unused.
 #define BIO_CTRL_EOF 2
 
 // BIO_CTRL_INFO is a legacy command that returns information specific to the
 // type of |BIO|. It is not safe to call generically and should not be
 // implemented in new |BIO| types.
 #define BIO_CTRL_INFO 3
 
 // BIO_CTRL_GET_CLOSE returns the close flag set by |BIO_CTRL_SET_CLOSE|. The
 // arguments are unused.
 #define BIO_CTRL_GET_CLOSE 8
 
 // BIO_CTRL_SET_CLOSE implements |BIO_set_close|. The |larg| argument is the
 // close flag.
 #define BIO_CTRL_SET_CLOSE 9
 
 // BIO_CTRL_PENDING implements |BIO_pending|. The arguments are unused.
 #define BIO_CTRL_PENDING 10
 
 // BIO_CTRL_FLUSH implements |BIO_flush|. The arguments are unused.
 #define BIO_CTRL_FLUSH 11
 
 // BIO_CTRL_WPENDING implements |BIO_wpending|. The arguments are unused.
 #define BIO_CTRL_WPENDING 13
 
 // BIO_CTRL_SET_CALLBACK sets an informational callback of type
 // int cb(BIO *bio, int state, int ret)
 #define BIO_CTRL_SET_CALLBACK 14
 
 // BIO_CTRL_GET_CALLBACK returns the callback set by |BIO_CTRL_SET_CALLBACK|.
 #define BIO_CTRL_GET_CALLBACK 15
 
 // The following are never used, but are defined to aid porting existing code.
 #define BIO_CTRL_SET 4
 #define BIO_CTRL_GET 5
 #define BIO_CTRL_PUSH 6
 #define BIO_CTRL_POP 7
 #define BIO_CTRL_DUP 12
 #define BIO_CTRL_SET_FILENAME 30
 
 
 // ex_data functions.
 //
 // See |ex_data.h| for details.
 
 OPENSSL_EXPORT int BIO_get_ex_new_index(long argl, void *argp,
                                         CRYPTO_EX_unused *unused,
                                         CRYPTO_EX_dup *dup_unused,
                                         CRYPTO_EX_free *free_func);
 OPENSSL_EXPORT int BIO_set_ex_data(BIO *bio, int idx, void *arg);
 OPENSSL_EXPORT void *BIO_get_ex_data(const BIO *bio, int idx);
 
 #define BIO_set_app_data(bio, arg) (BIO_set_ex_data(bio, 0, (char *)(arg)))
 #define BIO_get_app_data(bio) (BIO_get_ex_data(bio, 0))
 
 
 // Deprecated functions.
 
 typedef BIO_info_cb bio_info_cb;
 
 // BIO_f_base64 returns a filter |BIO| that base64-encodes data written into
 // it, and decodes data read from it. |BIO_gets| is not supported. Call
 // |BIO_flush| when done writing, to signal that no more data are to be
 // encoded. The flag |BIO_FLAGS_BASE64_NO_NL| may be set to encode all the data
 // on one line.
 //
 // Use |EVP_EncodeBlock| and |EVP_DecodeBase64| instead.
 OPENSSL_EXPORT const BIO_METHOD *BIO_f_base64(void);
 
 OPENSSL_EXPORT void BIO_set_retry_special(BIO *bio);
 
 // BIO_set_write_buffer_size returns zero.
 OPENSSL_EXPORT int BIO_set_write_buffer_size(BIO *bio, int buffer_size);
 
 // BIO_set_shutdown sets a method-specific "shutdown" bit on |bio|.
 OPENSSL_EXPORT void BIO_set_shutdown(BIO *bio, int shutdown);
 
 // BIO_get_shutdown returns the method-specific "shutdown" bit.
 OPENSSL_EXPORT int BIO_get_shutdown(BIO *bio);
 
 // BIO_meth_set_puts returns one. |BIO_puts| is implemented with |BIO_write| in
 // BoringSSL.
 OPENSSL_EXPORT int BIO_meth_set_puts(BIO_METHOD *method,
                                      int (*puts)(BIO *, const char *));
 
 #if !defined(OPENSSL_NO_SOCK)
 // The following functions return function pointers, possibly NULL, which are
 // compatible with the corresponding |BIO_meth_set_*| function. |method| must be
 // |BIO_s_socket| or the program will abort.
 //
 // Using these functions is inherently unsafe and fragile. It is not possible to
 // use them in a future-proof way. See
 // https://github.com/openssl/openssl/issues/26047 for details. BoringSSL
 // implements them solely for compatibility with Folly and older versions of
 // PostgreSQL. To work around the future-proofing problems, the return values
 // may diverge from the true implementation of |BIO_s_socket|.
 //
 // Caller should not use these functions. They are not necessary to define
 // custom |BIO_METHOD|s. Instead, callers should either:
 //
 // - Define a custom |BIO_METHOD| that owns a socket |BIO| somewhere in the
 //   custom data. See |BIO_set_data|.
 //
 // - Define a custom |BIO_METHOD| that wraps a socket |BIO| as a filter. See
 //   |BIO_push| and |BIO_next|.
 //
 // - Define a custom |BIO_METHOD| without |BIO_s_socket| at all. If not using
 //   the built-in read or write functions, |BIO_s_socket| only provides a no-op
 //   |BIO_CTRL_FLUSH| implementation. This can be implemented by the caller.
 OPENSSL_EXPORT int (*BIO_meth_get_write(const BIO_METHOD *method))(BIO *,
                                                                    const char *,
                                                                    int);
 OPENSSL_EXPORT int (*BIO_meth_get_read(const BIO_METHOD *method))(BIO *, char *,
                                                                   int);
 OPENSSL_EXPORT int (*BIO_meth_get_gets(const BIO_METHOD *method))(BIO *, char *,
                                                                   int);
 OPENSSL_EXPORT int (*BIO_meth_get_puts(const BIO_METHOD *method))(BIO *,
                                                                   const char *);
 OPENSSL_EXPORT long (*BIO_meth_get_ctrl(const BIO_METHOD *method))(BIO *, int,
                                                                    long,
                                                                    void *);
 OPENSSL_EXPORT int (*BIO_meth_get_create(const BIO_METHOD *method))(BIO *);
 OPENSSL_EXPORT int (*BIO_meth_get_destroy(const BIO_METHOD *method))(BIO *);
 OPENSSL_EXPORT long (*BIO_meth_get_callback_ctrl(const BIO_METHOD *method))(
     BIO *, int, BIO_info_cb *);
 #endif  // !OPENSSL_NO_SOCK
 
 
 // Private functions
 
 #define BIO_FLAGS_READ 0x01
 #define BIO_FLAGS_WRITE 0x02
 #define BIO_FLAGS_IO_SPECIAL 0x04
 #define BIO_FLAGS_RWS (BIO_FLAGS_READ | BIO_FLAGS_WRITE | BIO_FLAGS_IO_SPECIAL)
 #define BIO_FLAGS_SHOULD_RETRY 0x08
 #define BIO_FLAGS_BASE64_NO_NL 0x100
 // BIO_FLAGS_MEM_RDONLY is used with memory BIOs. It means we shouldn't free up
 // or change the data in any way.
 #define BIO_FLAGS_MEM_RDONLY 0x200
 
 // BIO_TYPE_DESCRIPTOR denotes that the |BIO| responds to the |BIO_C_SET_FD|
 // (|BIO_set_fd|) and |BIO_C_GET_FD| (|BIO_get_fd|) control hooks.
 #define BIO_TYPE_DESCRIPTOR 0x0100  // socket, fd, connect or accept
 #define BIO_TYPE_FILTER 0x0200
 #define BIO_TYPE_SOURCE_SINK 0x0400
 
 // These are the 'types' of BIOs
 #define BIO_TYPE_NONE 0
 #define BIO_TYPE_MEM (1 | BIO_TYPE_SOURCE_SINK)
 #define BIO_TYPE_FILE (2 | BIO_TYPE_SOURCE_SINK)
 #define BIO_TYPE_FD (4 | BIO_TYPE_SOURCE_SINK | BIO_TYPE_DESCRIPTOR)
 #define BIO_TYPE_SOCKET (5 | BIO_TYPE_SOURCE_SINK | BIO_TYPE_DESCRIPTOR)
 #define BIO_TYPE_NULL (6 | BIO_TYPE_SOURCE_SINK)
 #define BIO_TYPE_SSL (7 | BIO_TYPE_FILTER)
 #define BIO_TYPE_MD (8 | BIO_TYPE_FILTER)
 #define BIO_TYPE_BUFFER (9 | BIO_TYPE_FILTER)
 #define BIO_TYPE_CIPHER (10 | BIO_TYPE_FILTER)
 #define BIO_TYPE_BASE64 (11 | BIO_TYPE_FILTER)
 #define BIO_TYPE_CONNECT (12 | BIO_TYPE_SOURCE_SINK | BIO_TYPE_DESCRIPTOR)
 #define BIO_TYPE_ACCEPT (13 | BIO_TYPE_SOURCE_SINK | BIO_TYPE_DESCRIPTOR)
 #define BIO_TYPE_PROXY_CLIENT (14 | BIO_TYPE_FILTER)
 #define BIO_TYPE_PROXY_SERVER (15 | BIO_TYPE_FILTER)
 #define BIO_TYPE_NBIO_TEST (16 | BIO_TYPE_FILTER)
 #define BIO_TYPE_NULL_FILTER (17 | BIO_TYPE_FILTER)
 #define BIO_TYPE_BER (18 | BIO_TYPE_FILTER)       // BER -> bin filter
 #define BIO_TYPE_BIO (19 | BIO_TYPE_SOURCE_SINK)  // (half a) BIO pair
 #define BIO_TYPE_LINEBUFFER (20 | BIO_TYPE_FILTER)
 #define BIO_TYPE_DGRAM (21 | BIO_TYPE_SOURCE_SINK | BIO_TYPE_DESCRIPTOR)
 #define BIO_TYPE_ASN1 (22 | BIO_TYPE_FILTER)
 #define BIO_TYPE_COMP (23 | BIO_TYPE_FILTER)
 
 // BIO_TYPE_START is the first user-allocated |BIO| type. No pre-defined type,
 // flag bits aside, may exceed this value.
 #define BIO_TYPE_START 128
 
 #define BIO_C_SET_CONNECT 100
 #define BIO_C_DO_STATE_MACHINE 101
 #define BIO_C_SET_NBIO 102
 #define BIO_C_SET_PROXY_PARAM 103
 #define BIO_C_SET_FD 104
 #define BIO_C_GET_FD 105
 #define BIO_C_SET_FILE_PTR 106
 #define BIO_C_GET_FILE_PTR 107
 #define BIO_C_SET_FILENAME 108
 #define BIO_C_SET_SSL 109
 #define BIO_C_SET_MD 111
 #define BIO_C_GET_MD 112
 #define BIO_C_GET_CIPHER_STATUS 113
 #define BIO_C_SET_BUF_MEM 114
 #define BIO_C_GET_BUF_MEM_PTR 115
 #define BIO_C_GET_BUFF_NUM_LINES 116
 #define BIO_C_SET_BUFF_SIZE 117
 #define BIO_C_SET_ACCEPT 118
 #define BIO_C_SSL_MODE 119
 #define BIO_C_GET_MD_CTX 120
 #define BIO_C_GET_PROXY_PARAM 121
 #define BIO_C_SET_BUFF_READ_DATA 122  // data to read first
 #define BIO_C_GET_ACCEPT 124
 #define BIO_C_FILE_SEEK 128
 #define BIO_C_GET_CIPHER_CTX 129
 #define BIO_C_SET_BUF_MEM_EOF_RETURN 130  // return end of input value
 #define BIO_C_SET_BIND_MODE 131
 #define BIO_C_GET_BIND_MODE 132
 #define BIO_C_FILE_TELL 133
 #define BIO_C_GET_SOCKS 134
 #define BIO_C_SET_SOCKS 135
 
 #define BIO_C_SET_WRITE_BUF_SIZE 136  // for BIO_s_bio
 #define BIO_C_GET_WRITE_BUF_SIZE 137
 #define BIO_C_GET_WRITE_GUARANTEE 140
 #define BIO_C_GET_READ_REQUEST 141
 #define BIO_C_SHUTDOWN_WR 142
 #define BIO_C_NREAD0 143
 #define BIO_C_NREAD 144
 #define BIO_C_NWRITE0 145
 #define BIO_C_NWRITE 146
 #define BIO_C_RESET_READ_REQUEST 147
 #define BIO_C_SET_MD_CTX 148
 
 #define BIO_C_SET_PREFIX 149
 #define BIO_C_GET_PREFIX 150
 #define BIO_C_SET_SUFFIX 151
 #define BIO_C_GET_SUFFIX 152
 
 #define BIO_C_SET_EX_ARG 153
 #define BIO_C_GET_EX_ARG 154
 
 
 #if defined(__cplusplus)
 }  // extern C
 
 extern "C++" {
 
 BSSL_NAMESPACE_BEGIN
 
 BORINGSSL_MAKE_DELETER(BIO, BIO_free)
 BORINGSSL_MAKE_UP_REF(BIO, BIO_up_ref)
 BORINGSSL_MAKE_DELETER(BIO_METHOD, BIO_meth_free)
 
 BSSL_NAMESPACE_END
 
 }  // extern C++
 
 #endif
 
 #define BIO_R_BAD_FOPEN_MODE 100
 #define BIO_R_BROKEN_PIPE 101
 #define BIO_R_CONNECT_ERROR 102
 #define BIO_R_ERROR_SETTING_NBIO 103
 #define BIO_R_INVALID_ARGUMENT 104
 #define BIO_R_IN_USE 105
 #define BIO_R_KEEPALIVE 106
 #define BIO_R_NBIO_CONNECT_ERROR 107
 #define BIO_R_NO_HOSTNAME_SPECIFIED 108
 #define BIO_R_NO_PORT_SPECIFIED 109
 #define BIO_R_NO_SUCH_FILE 110
 #define BIO_R_NULL_PARAMETER 111
 #define BIO_R_SYS_LIB 112
 #define BIO_R_UNABLE_TO_CREATE_SOCKET 113
 #define BIO_R_UNINITIALIZED 114
 #define BIO_R_UNSUPPORTED_METHOD 115
 #define BIO_R_WRITE_TO_READ_ONLY_BIO 116
 
 #endif  // OPENSSL_HEADER_BIO_H