gnunet-android

asn1.h (94905B)

---

 // 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_ASN1_H
 #define OPENSSL_HEADER_ASN1_H
 
 #include <openssl/base.h>   // IWYU pragma: export
 
 #include <time.h>
 
 #include <openssl/bio.h>
 #include <openssl/bn.h>
 #include <openssl/stack.h>
 
 #if defined(__cplusplus)
 extern "C" {
 #endif
 
 
 // Legacy ASN.1 library.
 //
 // This header is part of OpenSSL's ASN.1 implementation. It is retained for
 // compatibility but should not be used by new code. The functions are difficult
 // to use correctly, and have buggy or non-standard behaviors. They are thus
 // particularly prone to behavior changes and API removals, as BoringSSL
 // iterates on these issues.
 //
 // Use the new |CBS| and |CBB| library in <openssl/bytestring.h> instead.
 
 
 // Tag constants.
 //
 // These constants are used in various APIs to specify ASN.1 types and tag
 // components. See the specific API's documentation for details on which values
 // are used and how.
 
 // The following constants are tag classes.
 #define V_ASN1_UNIVERSAL 0x00
 #define V_ASN1_APPLICATION 0x40
 #define V_ASN1_CONTEXT_SPECIFIC 0x80
 #define V_ASN1_PRIVATE 0xc0
 
 // V_ASN1_CONSTRUCTED indicates an element is constructed, rather than
 // primitive.
 #define V_ASN1_CONSTRUCTED 0x20
 
 // V_ASN1_PRIMITIVE_TAG is the highest tag number which can be encoded in a
 // single byte. Note this is unrelated to whether an element is constructed or
 // primitive.
 //
 // TODO(davidben): Make this private.
 #define V_ASN1_PRIMITIVE_TAG 0x1f
 
 // V_ASN1_MAX_UNIVERSAL is the highest supported universal tag number. It is
 // necessary to avoid ambiguity with |V_ASN1_NEG| and |MBSTRING_FLAG|.
 //
 // TODO(davidben): Make this private.
 #define V_ASN1_MAX_UNIVERSAL 0xff
 
 // V_ASN1_UNDEF is used in some APIs to indicate an ASN.1 element is omitted.
 #define V_ASN1_UNDEF (-1)
 
 // V_ASN1_OTHER is used in |ASN1_TYPE| to indicate a non-universal ASN.1 type.
 #define V_ASN1_OTHER (-3)
 
 // V_ASN1_ANY is used by the ASN.1 templates to indicate an ANY type.
 #define V_ASN1_ANY (-4)
 
 // V_ASN1_ANY_AS_STRING is used by the ASN.1 templates to indicate an ANY type
 // represented with |ASN1_STRING| instead of |ASN1_TYPE|.
 #define V_ASN1_ANY_AS_STRING (-5)
 
 // The following constants are tag numbers for universal types.
 #define V_ASN1_EOC 0
 #define V_ASN1_BOOLEAN 1
 #define V_ASN1_INTEGER 2
 #define V_ASN1_BIT_STRING 3
 #define V_ASN1_OCTET_STRING 4
 #define V_ASN1_NULL 5
 #define V_ASN1_OBJECT 6
 #define V_ASN1_OBJECT_DESCRIPTOR 7
 #define V_ASN1_EXTERNAL 8
 #define V_ASN1_REAL 9
 #define V_ASN1_ENUMERATED 10
 #define V_ASN1_UTF8STRING 12
 #define V_ASN1_SEQUENCE 16
 #define V_ASN1_SET 17
 #define V_ASN1_NUMERICSTRING 18
 #define V_ASN1_PRINTABLESTRING 19
 #define V_ASN1_T61STRING 20
 #define V_ASN1_TELETEXSTRING 20
 #define V_ASN1_VIDEOTEXSTRING 21
 #define V_ASN1_IA5STRING 22
 #define V_ASN1_UTCTIME 23
 #define V_ASN1_GENERALIZEDTIME 24
 #define V_ASN1_GRAPHICSTRING 25
 #define V_ASN1_ISO64STRING 26
 #define V_ASN1_VISIBLESTRING 26
 #define V_ASN1_GENERALSTRING 27
 #define V_ASN1_UNIVERSALSTRING 28
 #define V_ASN1_BMPSTRING 30
 
 // The following constants are used for |ASN1_STRING| values that represent
 // negative INTEGER and ENUMERATED values. See |ASN1_STRING| for more details.
 #define V_ASN1_NEG 0x100
 #define V_ASN1_NEG_INTEGER (V_ASN1_INTEGER | V_ASN1_NEG)
 #define V_ASN1_NEG_ENUMERATED (V_ASN1_ENUMERATED | V_ASN1_NEG)
 
 // The following constants are bitmask representations of ASN.1 types.
 #define B_ASN1_NUMERICSTRING 0x0001
 #define B_ASN1_PRINTABLESTRING 0x0002
 #define B_ASN1_T61STRING 0x0004
 #define B_ASN1_TELETEXSTRING 0x0004
 #define B_ASN1_VIDEOTEXSTRING 0x0008
 #define B_ASN1_IA5STRING 0x0010
 #define B_ASN1_GRAPHICSTRING 0x0020
 #define B_ASN1_ISO64STRING 0x0040
 #define B_ASN1_VISIBLESTRING 0x0040
 #define B_ASN1_GENERALSTRING 0x0080
 #define B_ASN1_UNIVERSALSTRING 0x0100
 #define B_ASN1_OCTET_STRING 0x0200
 #define B_ASN1_BIT_STRING 0x0400
 #define B_ASN1_BMPSTRING 0x0800
 #define B_ASN1_UTF8STRING 0x2000
 #define B_ASN1_UTCTIME 0x4000
 #define B_ASN1_GENERALIZEDTIME 0x8000
 #define B_ASN1_SEQUENCE 0x10000
 
 // ASN1_tag2bit converts |tag| from the tag number of a universal type to a
 // corresponding |B_ASN1_*| constant, or zero if |tag| has no bitmask.
 OPENSSL_EXPORT unsigned long ASN1_tag2bit(int tag);
 
 // ASN1_tag2str returns a string representation of |tag|, interpret as a tag
 // number for a universal type, or |V_ASN1_NEG_*|.
 OPENSSL_EXPORT const char *ASN1_tag2str(int tag);
 
 
 // API conventions.
 //
 // The following sample functions document the calling conventions used by
 // legacy ASN.1 APIs.
 
 #if 0  // Sample functions
 
 // d2i_SAMPLE parses a structure from up to |len| bytes at |*inp|. On success,
 // it advances |*inp| by the number of bytes read and returns a newly-allocated
 // |SAMPLE| object containing the parsed structure. If |out| is non-NULL, it
 // additionally frees the previous value at |*out| and updates |*out| to the
 // result. If parsing or allocating the result fails, it returns NULL.
 //
 // This function does not reject trailing data in the input. This allows the
 // caller to parse a sequence of concatenated structures. Callers parsing only
 // one structure should check for trailing data by comparing the updated |*inp|
 // with the end of the input.
 //
 // Note: If |out| and |*out| are both non-NULL, the object at |*out| is not
 // updated in-place. Instead, it is freed, and the pointer is updated to the
 // new object. This differs from OpenSSL. Callers are recommended to set |out|
 // to NULL and instead use the return value.
 SAMPLE *d2i_SAMPLE(SAMPLE **out, const uint8_t **inp, long len);
 
 // i2d_SAMPLE marshals |in|. On error, it returns a negative value. On success,
 // it returns the length of the result and outputs it via |outp| as follows:
 //
 // If |outp| is NULL, the function writes nothing. This mode can be used to size
 // buffers.
 //
 // If |outp| is non-NULL but |*outp| is NULL, the function sets |*outp| to a
 // newly-allocated buffer containing the result. The caller is responsible for
 // releasing |*outp| with |OPENSSL_free|. This mode is recommended for most
 // callers.
 //
 // If |outp| and |*outp| are non-NULL, the function writes the result to
 // |*outp|, which must have enough space available, and advances |*outp| just
 // past the output.
 //
 // WARNING: In the third mode, the function does not internally check output
 // bounds. Failing to correctly size the buffer will result in a potentially
 // exploitable memory error.
 int i2d_SAMPLE(const SAMPLE *in, uint8_t **outp);
 
 #endif  // Sample functions
 
 // The following typedefs are sometimes used for pointers to functions like
 // |d2i_SAMPLE| and |i2d_SAMPLE|. Note, however, that these act on |void*|.
 // Calling a function with a different pointer type is undefined in C, so this
 // is only valid with a wrapper.
 typedef void *d2i_of_void(void **, const unsigned char **, long);
 typedef int i2d_of_void(const void *, unsigned char **);
 
 
 // ASN.1 types.
 //
 // An |ASN1_ITEM| represents an ASN.1 type and allows working with ASN.1 types
 // generically.
 //
 // |ASN1_ITEM|s use a different namespace from C types and are accessed via
 // |ASN1_ITEM_*| macros. So, for example, |ASN1_OCTET_STRING| is both a C type
 // and the name of an |ASN1_ITEM|, referenced as
 // |ASN1_ITEM_rptr(ASN1_OCTET_STRING)|.
 //
 // Each |ASN1_ITEM| has a corresponding C type, typically with the same name,
 // which represents values in the ASN.1 type. This type is either a pointer type
 // or |ASN1_BOOLEAN|. When it is a pointer, NULL pointers represent omitted
 // values. For example, an OCTET STRING value is declared with the C type
 // |ASN1_OCTET_STRING*| and uses the |ASN1_ITEM| named |ASN1_OCTET_STRING|. An
 // OPTIONAL OCTET STRING uses the same C type and represents an omitted value
 // with a NULL pointer. |ASN1_BOOLEAN| is described in a later section.
 
 // DECLARE_ASN1_ITEM declares an |ASN1_ITEM| with name |name|. The |ASN1_ITEM|
 // may be referenced with |ASN1_ITEM_rptr|. Uses of this macro should document
 // the corresponding ASN.1 and C types.
 #define DECLARE_ASN1_ITEM(name) extern OPENSSL_EXPORT const ASN1_ITEM name##_it;
 
 // ASN1_ITEM_rptr returns the |const ASN1_ITEM *| named |name|.
 #define ASN1_ITEM_rptr(name) (&(name##_it))
 
 // ASN1_ITEM_EXP is an abstraction for referencing an |ASN1_ITEM| in a
 // constant-initialized structure, such as a method table. It exists because, on
 // some OpenSSL platforms, |ASN1_ITEM| references are indirected through
 // functions. Structures reference the |ASN1_ITEM| by declaring a field like
 // |ASN1_ITEM_EXP *item| and initializing it with |ASN1_ITEM_ref|.
 typedef const ASN1_ITEM ASN1_ITEM_EXP;
 
 // ASN1_ITEM_ref returns an |ASN1_ITEM_EXP*| for the |ASN1_ITEM| named |name|.
 #define ASN1_ITEM_ref(name) (&(name##_it))
 
 // ASN1_ITEM_ptr converts |iptr|, which must be an |ASN1_ITEM_EXP*| to a
 // |const ASN1_ITEM*|.
 #define ASN1_ITEM_ptr(iptr) (iptr)
 
 // ASN1_VALUE_st (aka |ASN1_VALUE|) is an opaque type used as a placeholder for
 // the C type corresponding to an |ASN1_ITEM|.
 typedef struct ASN1_VALUE_st ASN1_VALUE;
 
 // ASN1_item_new allocates a new value of the C type corresponding to |it|, or
 // NULL on error. On success, the caller must release the value with
 // |ASN1_item_free|, or the corresponding C type's free function, when done. The
 // new value will initialize fields of the value to some default state, such as
 // an empty string. Note, however, that this default state sometimes omits
 // required values, such as with CHOICE types.
 //
 // This function may not be used with |ASN1_ITEM|s whose C type is
 // |ASN1_BOOLEAN|.
 //
 // WARNING: Casting the result of this function to the wrong type is a
 // potentially exploitable memory error. Callers must ensure the value is used
 // consistently with |it|. Prefer using type-specific functions such as
 // |ASN1_OCTET_STRING_new|.
 OPENSSL_EXPORT ASN1_VALUE *ASN1_item_new(const ASN1_ITEM *it);
 
 // ASN1_item_free releases memory associated with |val|, which must be an object
 // of the C type corresponding to |it|.
 //
 // This function may not be used with |ASN1_ITEM|s whose C type is
 // |ASN1_BOOLEAN|.
 //
 // WARNING: Passing a pointer of the wrong type into this function is a
 // potentially exploitable memory error. Callers must ensure |val| is consistent
 // with |it|. Prefer using type-specific functions such as
 // |ASN1_OCTET_STRING_free|.
 OPENSSL_EXPORT void ASN1_item_free(ASN1_VALUE *val, const ASN1_ITEM *it);
 
 // ASN1_item_d2i parses the ASN.1 type |it| from up to |len| bytes at |*inp|.
 // It behaves like |d2i_SAMPLE|, except that |out| and the return value are cast
 // to |ASN1_VALUE| pointers.
 //
 // TODO(https://crbug.com/boringssl/444): C strict aliasing forbids type-punning
 // |T*| and |ASN1_VALUE*| the way this function signature does. When that bug is
 // resolved, we will need to pick which type |*out| is (probably |T*|). Do not
 // use a non-NULL |out| to avoid ending up on the wrong side of this question.
 //
 // This function may not be used with |ASN1_ITEM|s whose C type is
 // |ASN1_BOOLEAN|.
 //
 // WARNING: Casting the result of this function to the wrong type, or passing a
 // pointer of the wrong type into this function, are potentially exploitable
 // memory errors. Callers must ensure |out| is consistent with |it|. Prefer
 // using type-specific functions such as |d2i_ASN1_OCTET_STRING|.
 OPENSSL_EXPORT ASN1_VALUE *ASN1_item_d2i(ASN1_VALUE **out,
                                          const unsigned char **inp, long len,
                                          const ASN1_ITEM *it);
 
 // ASN1_item_i2d marshals |val| as the ASN.1 type associated with |it|, as
 // described in |i2d_SAMPLE|.
 //
 // This function may not be used with |ASN1_ITEM|s whose C type is
 // |ASN1_BOOLEAN|.
 //
 // WARNING: Passing a pointer of the wrong type into this function is a
 // potentially exploitable memory error. Callers must ensure |val| is consistent
 // with |it|. Prefer using type-specific functions such as
 // |i2d_ASN1_OCTET_STRING|.
 OPENSSL_EXPORT int ASN1_item_i2d(ASN1_VALUE *val, unsigned char **outp,
                                  const ASN1_ITEM *it);
 
 // ASN1_item_dup returns a newly-allocated copy of |x|, or NULL on error. |x|
 // must be an object of |it|'s C type.
 //
 // This function may not be used with |ASN1_ITEM|s whose C type is
 // |ASN1_BOOLEAN|.
 //
 // WARNING: Casting the result of this function to the wrong type, or passing a
 // pointer of the wrong type into this function, are potentially exploitable
 // memory errors. Prefer using type-specific functions such as
 // |ASN1_STRING_dup|.
 OPENSSL_EXPORT void *ASN1_item_dup(const ASN1_ITEM *it, void *x);
 
 // The following functions behave like |ASN1_item_d2i| but read from |in|
 // instead. |out| is the same parameter as in |ASN1_item_d2i|, but written with
 // |void*| instead. The return values similarly match.
 //
 // These functions may not be used with |ASN1_ITEM|s whose C type is
 // |ASN1_BOOLEAN|.
 //
 // WARNING: These functions do not bound how much data is read from |in|.
 // Parsing an untrusted input could consume unbounded memory.
 OPENSSL_EXPORT void *ASN1_item_d2i_fp(const ASN1_ITEM *it, FILE *in, void *out);
 OPENSSL_EXPORT void *ASN1_item_d2i_bio(const ASN1_ITEM *it, BIO *in, void *out);
 
 // The following functions behave like |ASN1_item_i2d| but write to |out|
 // instead. |in| is the same parameter as in |ASN1_item_i2d|, but written with
 // |void*| instead.
 //
 // These functions may not be used with |ASN1_ITEM|s whose C type is
 // |ASN1_BOOLEAN|.
 OPENSSL_EXPORT int ASN1_item_i2d_fp(const ASN1_ITEM *it, FILE *out, void *in);
 OPENSSL_EXPORT int ASN1_item_i2d_bio(const ASN1_ITEM *it, BIO *out, void *in);
 
 // ASN1_item_unpack parses |oct|'s contents as |it|'s ASN.1 type. It returns a
 // newly-allocated instance of |it|'s C type on success, or NULL on error.
 //
 // This function may not be used with |ASN1_ITEM|s whose C type is
 // |ASN1_BOOLEAN|.
 //
 // WARNING: Casting the result of this function to the wrong type is a
 // potentially exploitable memory error. Callers must ensure the value is used
 // consistently with |it|.
 OPENSSL_EXPORT void *ASN1_item_unpack(const ASN1_STRING *oct,
                                       const ASN1_ITEM *it);
 
 // ASN1_item_pack marshals |obj| as |it|'s ASN.1 type. If |out| is NULL, it
 // returns a newly-allocated |ASN1_STRING| with the result, or NULL on error.
 // If |out| is non-NULL, but |*out| is NULL, it does the same but additionally
 // sets |*out| to the result. If both |out| and |*out| are non-NULL, it writes
 // the result to |*out| and returns |*out| on success or NULL on error.
 //
 // This function may not be used with |ASN1_ITEM|s whose C type is
 // |ASN1_BOOLEAN|.
 //
 // WARNING: Passing a pointer of the wrong type into this function is a
 // potentially exploitable memory error. Callers must ensure |val| is consistent
 // with |it|.
 OPENSSL_EXPORT ASN1_STRING *ASN1_item_pack(void *obj, const ASN1_ITEM *it,
                                            ASN1_STRING **out);
 
 
 // Booleans.
 //
 // This library represents ASN.1 BOOLEAN values with |ASN1_BOOLEAN|, which is an
 // integer type. FALSE is zero, TRUE is 0xff, and an omitted OPTIONAL BOOLEAN is
 // -1.
 
 // ASN1_BOOLEAN_FALSE is FALSE as an |ASN1_BOOLEAN|.
 #define ASN1_BOOLEAN_FALSE 0
 
 // ASN1_BOOLEAN_TRUE is TRUE as an |ASN1_BOOLEAN|. Some code incorrectly uses
 // 1, so prefer |b != ASN1_BOOLEAN_FALSE| over |b == ASN1_BOOLEAN_TRUE|.
 #define ASN1_BOOLEAN_TRUE 0xff
 
 // ASN1_BOOLEAN_NONE, in contexts where the |ASN1_BOOLEAN| represents an
 // OPTIONAL BOOLEAN, is an omitted value. Using this value in other contexts is
 // undefined and may be misinterpreted as TRUE.
 #define ASN1_BOOLEAN_NONE (-1)
 
 // d2i_ASN1_BOOLEAN parses a DER-encoded ASN.1 BOOLEAN from up to |len| bytes at
 // |*inp|. On success, it advances |*inp| by the number of bytes read and
 // returns the result. If |out| is non-NULL, it additionally writes the result
 // to |*out|. On error, it returns |ASN1_BOOLEAN_NONE|.
 //
 // This function does not reject trailing data in the input. This allows the
 // caller to parse a sequence of concatenated structures. Callers parsing only
 // one structure should check for trailing data by comparing the updated |*inp|
 // with the end of the input.
 //
 // WARNING: This function's is slightly different from other |d2i_*| functions
 // because |ASN1_BOOLEAN| is not a pointer type.
 OPENSSL_EXPORT ASN1_BOOLEAN d2i_ASN1_BOOLEAN(ASN1_BOOLEAN *out,
                                              const unsigned char **inp,
                                              long len);
 
 // i2d_ASN1_BOOLEAN marshals |a| as a DER-encoded ASN.1 BOOLEAN, as described in
 // |i2d_SAMPLE|.
 OPENSSL_EXPORT int i2d_ASN1_BOOLEAN(ASN1_BOOLEAN a, unsigned char **outp);
 
 // The following |ASN1_ITEM|s have ASN.1 type BOOLEAN and C type |ASN1_BOOLEAN|.
 // |ASN1_TBOOLEAN| and |ASN1_FBOOLEAN| must be marked OPTIONAL. When omitted,
 // they are parsed as TRUE and FALSE, respectively, rather than
 // |ASN1_BOOLEAN_NONE|.
 DECLARE_ASN1_ITEM(ASN1_BOOLEAN)
 DECLARE_ASN1_ITEM(ASN1_TBOOLEAN)
 DECLARE_ASN1_ITEM(ASN1_FBOOLEAN)
 
 
 // Strings.
 //
 // ASN.1 contains a myriad of string types, as well as types that contain data
 // that may be encoded into a string. This library uses a single type,
 // |ASN1_STRING|, to represent most values.
 
 // An asn1_string_st (aka |ASN1_STRING|) represents a value of a string-like
 // ASN.1 type. It contains a |type| field, and a byte string |data| field with a
 // type-specific representation. This type-specific representation does not
 // always correspond to the DER encoding of the type.
 //
 // If |type| is one of |V_ASN1_OCTET_STRING|, |V_ASN1_UTF8STRING|,
 // |V_ASN1_NUMERICSTRING|, |V_ASN1_PRINTABLESTRING|, |V_ASN1_T61STRING|,
 // |V_ASN1_VIDEOTEXSTRING|, |V_ASN1_IA5STRING|, |V_ASN1_GRAPHICSTRING|,
 // |V_ASN1_ISO64STRING|, |V_ASN1_VISIBLESTRING|, |V_ASN1_GENERALSTRING|,
 // |V_ASN1_UNIVERSALSTRING|, or |V_ASN1_BMPSTRING|, the object represents an
 // ASN.1 string type. The data contains the byte representation of the
 // string.
 //
 // If |type| is |V_ASN1_BIT_STRING|, the object represents a BIT STRING value.
 // See bit string documentation below for the data and flags.
 //
 // If |type| is one of |V_ASN1_INTEGER|, |V_ASN1_NEG_INTEGER|,
 // |V_ASN1_ENUMERATED|, or |V_ASN1_NEG_ENUMERATED|, the object represents an
 // INTEGER or ENUMERATED value. See integer documentation below for details.
 //
 // If |type| is |V_ASN1_GENERALIZEDTIME| or |V_ASN1_UTCTIME|, the object
 // represents a GeneralizedTime or UTCTime value, respectively. The data
 // contains the DER encoding of the value. For example, the UNIX epoch would be
 // "19700101000000Z" for a GeneralizedTime and "700101000000Z" for a UTCTime.
 //
 // If |type| is |V_ASN1_SEQUENCE|, |V_ASN1_SET|, or |V_ASN1_OTHER|, the object
 // represents a SEQUENCE, SET, or arbitrary ASN.1 value, respectively. Unlike
 // the above cases, the data contains the DER encoding of the entire structure,
 // including the header. If the value is explicitly or implicitly tagged, this
 // too will be reflected in the data field. As this case handles unknown types,
 // the contents are not checked when parsing or serializing.
 //
 // Other values of |type| do not represent a valid ASN.1 value, though
 // default-constructed objects may set |type| to -1. Such objects cannot be
 // serialized.
 //
 // |ASN1_STRING| additionally has the following typedefs: |ASN1_BIT_STRING|,
 // |ASN1_BMPSTRING|, |ASN1_ENUMERATED|, |ASN1_GENERALIZEDTIME|,
 // |ASN1_GENERALSTRING|, |ASN1_IA5STRING|, |ASN1_INTEGER|, |ASN1_OCTET_STRING|,
 // |ASN1_PRINTABLESTRING|, |ASN1_T61STRING|, |ASN1_TIME|,
 // |ASN1_UNIVERSALSTRING|, |ASN1_UTCTIME|, |ASN1_UTF8STRING|, and
 // |ASN1_VISIBLESTRING|. Other than |ASN1_TIME|, these correspond to universal
 // ASN.1 types. |ASN1_TIME| represents a CHOICE of UTCTime and GeneralizedTime,
 // with a cutoff of 2049, as used in Section 4.1.2.5 of RFC 5280.
 //
 // For clarity, callers are encouraged to use the appropriate typedef when
 // available. They are the same type as |ASN1_STRING|, so a caller may freely
 // pass them into functions expecting |ASN1_STRING|, such as
 // |ASN1_STRING_length|.
 //
 // If a function returns an |ASN1_STRING| where the typedef or ASN.1 structure
 // implies constraints on |type|, callers may assume that |type| is correct.
 // However, if a function takes an |ASN1_STRING| as input, callers must ensure
 // |type| matches. These invariants are not captured by the C type system and
 // may not be checked at runtime. For example, callers may assume the output of
 // |X509_get0_serialNumber| has type |V_ASN1_INTEGER| or |V_ASN1_NEG_INTEGER|.
 // Callers must not pass a string of type |V_ASN1_OCTET_STRING| to
 // |X509_set_serialNumber|. Doing so may break invariants on the |X509| object
 // and break the |X509_get0_serialNumber| invariant.
 //
 // TODO(https://crbug.com/boringssl/445): This is very unfriendly. Getting the
 // type field wrong should not cause memory errors, but it may do strange
 // things. We should add runtime checks to anything that consumes |ASN1_STRING|s
 // from the caller.
 struct asn1_string_st {
   int length;
   int type;
   unsigned char *data;
   long flags;
 };
 
 // ASN1_STRING_FLAG_BITS_LEFT indicates, in a BIT STRING |ASN1_STRING|, that
 // flags & 0x7 contains the number of padding bits added to the BIT STRING
 // value. When not set, all trailing zero bits in the last byte are implicitly
 // treated as padding. This behavior is deprecated and should not be used.
 #define ASN1_STRING_FLAG_BITS_LEFT 0x08
 
 // ASN1_STRING_type_new returns a newly-allocated empty |ASN1_STRING| object of
 // type |type|, or NULL on error.
 OPENSSL_EXPORT ASN1_STRING *ASN1_STRING_type_new(int type);
 
 // ASN1_STRING_new returns a newly-allocated empty |ASN1_STRING| object with an
 // arbitrary type. Prefer one of the type-specific constructors, such as
 // |ASN1_OCTET_STRING_new|, or |ASN1_STRING_type_new|.
 OPENSSL_EXPORT ASN1_STRING *ASN1_STRING_new(void);
 
 // ASN1_STRING_free releases memory associated with |str|.
 OPENSSL_EXPORT void ASN1_STRING_free(ASN1_STRING *str);
 
 // ASN1_STRING_copy sets |dst| to a copy of |str|. It returns one on success and
 // zero on error.
 OPENSSL_EXPORT int ASN1_STRING_copy(ASN1_STRING *dst, const ASN1_STRING *str);
 
 // ASN1_STRING_dup returns a newly-allocated copy of |str|, or NULL on error.
 OPENSSL_EXPORT ASN1_STRING *ASN1_STRING_dup(const ASN1_STRING *str);
 
 // ASN1_STRING_type returns the type of |str|. This value will be one of the
 // |V_ASN1_*| constants.
 OPENSSL_EXPORT int ASN1_STRING_type(const ASN1_STRING *str);
 
 // ASN1_STRING_get0_data returns a pointer to |str|'s contents. Callers should
 // use |ASN1_STRING_length| to determine the length of the string. The string
 // may have embedded NUL bytes and may not be NUL-terminated.
 //
 // The contents of an |ASN1_STRING| encode the value in some type-specific
 // representation that does not always correspond to the DER encoding of the
 // type. See the documentation for |ASN1_STRING| for details.
 OPENSSL_EXPORT const unsigned char *ASN1_STRING_get0_data(
     const ASN1_STRING *str);
 
 // ASN1_STRING_data returns a mutable pointer to |str|'s contents. Callers
 // should use |ASN1_STRING_length| to determine the length of the string. The
 // string may have embedded NUL bytes and may not be NUL-terminated.
 //
 // The contents of an |ASN1_STRING| encode the value in some type-specific
 // representation that does not always correspond to the DER encoding of the
 // type. See the documentation for |ASN1_STRING| for details.
 //
 // Prefer |ASN1_STRING_get0_data|.
 OPENSSL_EXPORT unsigned char *ASN1_STRING_data(ASN1_STRING *str);
 
 // ASN1_STRING_length returns the length of |str|, in bytes.
 //
 // The contents of an |ASN1_STRING| encode the value in some type-specific
 // representation that does not always correspond to the DER encoding of the
 // type. See the documentation for |ASN1_STRING| for details.
 OPENSSL_EXPORT int ASN1_STRING_length(const ASN1_STRING *str);
 
 // ASN1_STRING_cmp compares |a| and |b|'s type and contents. It returns an
 // integer equal to, less than, or greater than zero if |a| is equal to, less
 // than, or greater than |b|, respectively. This function compares by length,
 // then data, then type. Note the data compared is the |ASN1_STRING| internal
 // representation and the type order is arbitrary. While this comparison is
 // suitable for sorting, callers should not rely on the exact order when |a|
 // and |b| are different types.
 //
 // Note that, if |a| and |b| are INTEGERs, this comparison does not order the
 // values numerically. For a numerical comparison, use |ASN1_INTEGER_cmp|.
 OPENSSL_EXPORT int ASN1_STRING_cmp(const ASN1_STRING *a, const ASN1_STRING *b);
 
 // ASN1_STRING_set sets the contents of |str| to a copy of |len| bytes from
 // |data|. It returns one on success and zero on error. If |data| is NULL, it
 // updates the length and allocates the buffer as needed, but does not
 // initialize the contents.
 OPENSSL_EXPORT int ASN1_STRING_set(ASN1_STRING *str, const void *data,
                                    ossl_ssize_t len);
 
 // ASN1_STRING_set0 sets the contents of |str| to |len| bytes from |data|. It
 // takes ownership of |data|, which must have been allocated with
 // |OPENSSL_malloc|.
 OPENSSL_EXPORT void ASN1_STRING_set0(ASN1_STRING *str, void *data, int len);
 
 // The following functions call |ASN1_STRING_type_new| with the corresponding
 // |V_ASN1_*| constant.
 OPENSSL_EXPORT ASN1_BMPSTRING *ASN1_BMPSTRING_new(void);
 OPENSSL_EXPORT ASN1_GENERALSTRING *ASN1_GENERALSTRING_new(void);
 OPENSSL_EXPORT ASN1_IA5STRING *ASN1_IA5STRING_new(void);
 OPENSSL_EXPORT ASN1_OCTET_STRING *ASN1_OCTET_STRING_new(void);
 OPENSSL_EXPORT ASN1_PRINTABLESTRING *ASN1_PRINTABLESTRING_new(void);
 OPENSSL_EXPORT ASN1_T61STRING *ASN1_T61STRING_new(void);
 OPENSSL_EXPORT ASN1_UNIVERSALSTRING *ASN1_UNIVERSALSTRING_new(void);
 OPENSSL_EXPORT ASN1_UTF8STRING *ASN1_UTF8STRING_new(void);
 OPENSSL_EXPORT ASN1_VISIBLESTRING *ASN1_VISIBLESTRING_new(void);
 
 // The following functions call |ASN1_STRING_free|.
 OPENSSL_EXPORT void ASN1_BMPSTRING_free(ASN1_BMPSTRING *str);
 OPENSSL_EXPORT void ASN1_GENERALSTRING_free(ASN1_GENERALSTRING *str);
 OPENSSL_EXPORT void ASN1_IA5STRING_free(ASN1_IA5STRING *str);
 OPENSSL_EXPORT void ASN1_OCTET_STRING_free(ASN1_OCTET_STRING *str);
 OPENSSL_EXPORT void ASN1_PRINTABLESTRING_free(ASN1_PRINTABLESTRING *str);
 OPENSSL_EXPORT void ASN1_T61STRING_free(ASN1_T61STRING *str);
 OPENSSL_EXPORT void ASN1_UNIVERSALSTRING_free(ASN1_UNIVERSALSTRING *str);
 OPENSSL_EXPORT void ASN1_UTF8STRING_free(ASN1_UTF8STRING *str);
 OPENSSL_EXPORT void ASN1_VISIBLESTRING_free(ASN1_VISIBLESTRING *str);
 
 // The following functions parse up to |len| bytes from |*inp| as a
 // DER-encoded ASN.1 value of the corresponding type, as described in
 // |d2i_SAMPLE|.
 OPENSSL_EXPORT ASN1_BMPSTRING *d2i_ASN1_BMPSTRING(ASN1_BMPSTRING **out,
                                                   const uint8_t **inp,
                                                   long len);
 OPENSSL_EXPORT ASN1_GENERALSTRING *d2i_ASN1_GENERALSTRING(
     ASN1_GENERALSTRING **out, const uint8_t **inp, long len);
 OPENSSL_EXPORT ASN1_IA5STRING *d2i_ASN1_IA5STRING(ASN1_IA5STRING **out,
                                                   const uint8_t **inp,
                                                   long len);
 OPENSSL_EXPORT ASN1_OCTET_STRING *d2i_ASN1_OCTET_STRING(ASN1_OCTET_STRING **out,
                                                         const uint8_t **inp,
                                                         long len);
 OPENSSL_EXPORT ASN1_PRINTABLESTRING *d2i_ASN1_PRINTABLESTRING(
     ASN1_PRINTABLESTRING **out, const uint8_t **inp, long len);
 OPENSSL_EXPORT ASN1_T61STRING *d2i_ASN1_T61STRING(ASN1_T61STRING **out,
                                                   const uint8_t **inp,
                                                   long len);
 OPENSSL_EXPORT ASN1_UNIVERSALSTRING *d2i_ASN1_UNIVERSALSTRING(
     ASN1_UNIVERSALSTRING **out, const uint8_t **inp, long len);
 OPENSSL_EXPORT ASN1_UTF8STRING *d2i_ASN1_UTF8STRING(ASN1_UTF8STRING **out,
                                                     const uint8_t **inp,
                                                     long len);
 OPENSSL_EXPORT ASN1_VISIBLESTRING *d2i_ASN1_VISIBLESTRING(
     ASN1_VISIBLESTRING **out, const uint8_t **inp, long len);
 
 // The following functions marshal |in| as a DER-encoded ASN.1 value of the
 // corresponding type, as described in |i2d_SAMPLE|.
 OPENSSL_EXPORT int i2d_ASN1_BMPSTRING(const ASN1_BMPSTRING *in, uint8_t **outp);
 OPENSSL_EXPORT int i2d_ASN1_GENERALSTRING(const ASN1_GENERALSTRING *in,
                                           uint8_t **outp);
 OPENSSL_EXPORT int i2d_ASN1_IA5STRING(const ASN1_IA5STRING *in, uint8_t **outp);
 OPENSSL_EXPORT int i2d_ASN1_OCTET_STRING(const ASN1_OCTET_STRING *in,
                                          uint8_t **outp);
 OPENSSL_EXPORT int i2d_ASN1_PRINTABLESTRING(const ASN1_PRINTABLESTRING *in,
                                             uint8_t **outp);
 OPENSSL_EXPORT int i2d_ASN1_T61STRING(const ASN1_T61STRING *in, uint8_t **outp);
 OPENSSL_EXPORT int i2d_ASN1_UNIVERSALSTRING(const ASN1_UNIVERSALSTRING *in,
                                             uint8_t **outp);
 OPENSSL_EXPORT int i2d_ASN1_UTF8STRING(const ASN1_UTF8STRING *in,
                                        uint8_t **outp);
 OPENSSL_EXPORT int i2d_ASN1_VISIBLESTRING(const ASN1_VISIBLESTRING *in,
                                           uint8_t **outp);
 
 // The following |ASN1_ITEM|s have the ASN.1 type referred to in their name and
 // C type |ASN1_STRING*|. The C type may also be written as the corresponding
 // typedef.
 DECLARE_ASN1_ITEM(ASN1_BMPSTRING)
 DECLARE_ASN1_ITEM(ASN1_GENERALSTRING)
 DECLARE_ASN1_ITEM(ASN1_IA5STRING)
 DECLARE_ASN1_ITEM(ASN1_OCTET_STRING)
 DECLARE_ASN1_ITEM(ASN1_PRINTABLESTRING)
 DECLARE_ASN1_ITEM(ASN1_T61STRING)
 DECLARE_ASN1_ITEM(ASN1_UNIVERSALSTRING)
 DECLARE_ASN1_ITEM(ASN1_UTF8STRING)
 DECLARE_ASN1_ITEM(ASN1_VISIBLESTRING)
 
 // ASN1_OCTET_STRING_dup calls |ASN1_STRING_dup|.
 OPENSSL_EXPORT ASN1_OCTET_STRING *ASN1_OCTET_STRING_dup(
     const ASN1_OCTET_STRING *a);
 
 // ASN1_OCTET_STRING_cmp calls |ASN1_STRING_cmp|.
 OPENSSL_EXPORT int ASN1_OCTET_STRING_cmp(const ASN1_OCTET_STRING *a,
                                          const ASN1_OCTET_STRING *b);
 
 // ASN1_OCTET_STRING_set calls |ASN1_STRING_set|.
 OPENSSL_EXPORT int ASN1_OCTET_STRING_set(ASN1_OCTET_STRING *str,
                                          const unsigned char *data, int len);
 
 // ASN1_STRING_to_UTF8 converts |in| to UTF-8. On success, sets |*out| to a
 // newly-allocated buffer containing the resulting string and returns the length
 // of the string. The caller must call |OPENSSL_free| to release |*out| when
 // done. On error, it returns a negative number.
 OPENSSL_EXPORT int ASN1_STRING_to_UTF8(unsigned char **out,
                                        const ASN1_STRING *in);
 
 // The following formats define encodings for use with functions like
 // |ASN1_mbstring_copy|. Note |MBSTRING_ASC| refers to Latin-1, not ASCII.
 #define MBSTRING_FLAG 0x1000
 #define MBSTRING_UTF8 (MBSTRING_FLAG)
 #define MBSTRING_ASC (MBSTRING_FLAG | 1)
 #define MBSTRING_BMP (MBSTRING_FLAG | 2)
 #define MBSTRING_UNIV (MBSTRING_FLAG | 4)
 
 // DIRSTRING_TYPE contains the valid string types in an X.509 DirectoryString.
 #define DIRSTRING_TYPE                                            \
   (B_ASN1_PRINTABLESTRING | B_ASN1_T61STRING | B_ASN1_BMPSTRING | \
    B_ASN1_UTF8STRING)
 
 // PKCS9STRING_TYPE contains the valid string types in a PKCS9String.
 #define PKCS9STRING_TYPE (DIRSTRING_TYPE | B_ASN1_IA5STRING)
 
 // ASN1_mbstring_copy converts |len| bytes from |in| to an ASN.1 string. If
 // |len| is -1, |in| must be NUL-terminated and the length is determined by
 // |strlen|. |in| is decoded according to |inform|, which must be one of
 // |MBSTRING_*|. |mask| determines the set of valid output types and is a
 // bitmask containing a subset of |B_ASN1_PRINTABLESTRING|, |B_ASN1_IA5STRING|,
 // |B_ASN1_T61STRING|, |B_ASN1_BMPSTRING|, |B_ASN1_UNIVERSALSTRING|, and
 // |B_ASN1_UTF8STRING|, in that preference order. This function chooses the
 // first output type in |mask| which can represent |in|. It interprets T61String
 // as Latin-1, rather than T.61.
 //
 // If |mask| is zero, |DIRSTRING_TYPE| is used by default.
 //
 // On success, this function returns the |V_ASN1_*| constant corresponding to
 // the selected output type and, if |out| and |*out| are both non-NULL, updates
 // the object at |*out| with the result. If |out| is non-NULL and |*out| is
 // NULL, it instead sets |*out| to a newly-allocated |ASN1_STRING| containing
 // the result. If |out| is NULL, it returns the selected output type without
 // constructing an |ASN1_STRING|. On error, this function returns -1.
 OPENSSL_EXPORT int ASN1_mbstring_copy(ASN1_STRING **out, const uint8_t *in,
                                       ossl_ssize_t len, int inform,
                                       unsigned long mask);
 
 // ASN1_mbstring_ncopy behaves like |ASN1_mbstring_copy| but returns an error if
 // the input is less than |minsize| or greater than |maxsize| codepoints long. A
 // |maxsize| value of zero is ignored. Note the sizes are measured in
 // codepoints, not output bytes.
 OPENSSL_EXPORT int ASN1_mbstring_ncopy(ASN1_STRING **out, const uint8_t *in,
                                        ossl_ssize_t len, int inform,
                                        unsigned long mask, ossl_ssize_t minsize,
                                        ossl_ssize_t maxsize);
 
 // ASN1_STRING_set_by_NID behaves like |ASN1_mbstring_ncopy|, but determines
 // |mask|, |minsize|, and |maxsize| based on |nid|. When |nid| is a recognized
 // X.509 attribute type, it will pick a suitable ASN.1 string type and bounds.
 // For most attribute types, it preferentially chooses UTF8String. If |nid| is
 // unrecognized, it uses UTF8String by default.
 //
 // Slightly unlike |ASN1_mbstring_ncopy|, this function interprets |out| and
 // returns its result as follows: If |out| is NULL, it returns a newly-allocated
 // |ASN1_STRING| containing the result. If |out| is non-NULL and
 // |*out| is NULL, it additionally sets |*out| to the result. If both |out| and
 // |*out| are non-NULL, it instead updates the object at |*out| and returns
 // |*out|. In all cases, it returns NULL on error.
 //
 // This function supports the following NIDs: |NID_countryName|,
 // |NID_dnQualifier|, |NID_domainComponent|, |NID_friendlyName|,
 // |NID_givenName|, |NID_initials|, |NID_localityName|, |NID_ms_csp_name|,
 // |NID_name|, |NID_organizationalUnitName|, |NID_organizationName|,
 // |NID_pkcs9_challengePassword|, |NID_pkcs9_emailAddress|,
 // |NID_pkcs9_unstructuredAddress|, |NID_pkcs9_unstructuredName|,
 // |NID_serialNumber|, |NID_stateOrProvinceName|, and |NID_surname|. Additional
 // NIDs may be registered with |ASN1_STRING_set_by_NID|, but it is recommended
 // to call |ASN1_mbstring_ncopy| directly instead.
 OPENSSL_EXPORT ASN1_STRING *ASN1_STRING_set_by_NID(ASN1_STRING **out,
                                                    const unsigned char *in,
                                                    ossl_ssize_t len, int inform,
                                                    int nid);
 
 // STABLE_NO_MASK causes |ASN1_STRING_TABLE_add| to allow types other than
 // UTF8String.
 #define STABLE_NO_MASK 0x02
 
 // ASN1_STRING_TABLE_add registers the corresponding parameters with |nid|, for
 // use with |ASN1_STRING_set_by_NID|. It returns one on success and zero on
 // error. It is an error to call this function if |nid| is a built-in NID, or
 // was already registered by a previous call.
 //
 // WARNING: This function affects global state in the library. If two libraries
 // in the same address space register information for the same OID, one call
 // will fail. Prefer directly passing the desired parametrs to
 // |ASN1_mbstring_copy| or |ASN1_mbstring_ncopy| instead.
 OPENSSL_EXPORT int ASN1_STRING_TABLE_add(int nid, long minsize, long maxsize,
                                          unsigned long mask,
                                          unsigned long flags);
 
 
 // Multi-strings.
 //
 // A multi-string, or "MSTRING", is an |ASN1_STRING| that represents a CHOICE of
 // several string or string-like types, such as X.509's DirectoryString. The
 // |ASN1_STRING|'s type field determines which type is used.
 //
 // Multi-string types are associated with a bitmask, using the |B_ASN1_*|
 // constants, which defines which types are valid.
 
 // B_ASN1_DIRECTORYSTRING is a bitmask of types allowed in an X.509
 // DirectoryString (RFC 5280).
 #define B_ASN1_DIRECTORYSTRING                                        \
   (B_ASN1_PRINTABLESTRING | B_ASN1_TELETEXSTRING | B_ASN1_BMPSTRING | \
    B_ASN1_UNIVERSALSTRING | B_ASN1_UTF8STRING)
 
 // DIRECTORYSTRING_new returns a newly-allocated |ASN1_STRING| with type -1, or
 // NULL on error. The resulting |ASN1_STRING| is not a valid X.509
 // DirectoryString until initialized with a value.
 OPENSSL_EXPORT ASN1_STRING *DIRECTORYSTRING_new(void);
 
 // DIRECTORYSTRING_free calls |ASN1_STRING_free|.
 OPENSSL_EXPORT void DIRECTORYSTRING_free(ASN1_STRING *str);
 
 // d2i_DIRECTORYSTRING parses up to |len| bytes from |*inp| as a DER-encoded
 // X.509 DirectoryString (RFC 5280), as described in |d2i_SAMPLE|.
 //
 // TODO(https://crbug.com/boringssl/354): This function currently also accepts
 // BER, but this will be removed in the future.
 //
 // TODO(https://crbug.com/boringssl/449): DirectoryString's non-empty string
 // requirement is not currently enforced.
 OPENSSL_EXPORT ASN1_STRING *d2i_DIRECTORYSTRING(ASN1_STRING **out,
                                                 const uint8_t **inp, long len);
 
 // i2d_DIRECTORYSTRING marshals |in| as a DER-encoded X.509 DirectoryString (RFC
 // 5280), as described in |i2d_SAMPLE|.
 OPENSSL_EXPORT int i2d_DIRECTORYSTRING(const ASN1_STRING *in, uint8_t **outp);
 
 // DIRECTORYSTRING is an |ASN1_ITEM| whose ASN.1 type is X.509 DirectoryString
 // (RFC 5280) and C type is |ASN1_STRING*|.
 DECLARE_ASN1_ITEM(DIRECTORYSTRING)
 
 // B_ASN1_DISPLAYTEXT is a bitmask of types allowed in an X.509 DisplayText (RFC
 // 5280).
 #define B_ASN1_DISPLAYTEXT                                      \
   (B_ASN1_IA5STRING | B_ASN1_VISIBLESTRING | B_ASN1_BMPSTRING | \
    B_ASN1_UTF8STRING)
 
 // DISPLAYTEXT_new returns a newly-allocated |ASN1_STRING| with type -1, or NULL
 // on error. The resulting |ASN1_STRING| is not a valid X.509 DisplayText until
 // initialized with a value.
 OPENSSL_EXPORT ASN1_STRING *DISPLAYTEXT_new(void);
 
 // DISPLAYTEXT_free calls |ASN1_STRING_free|.
 OPENSSL_EXPORT void DISPLAYTEXT_free(ASN1_STRING *str);
 
 // d2i_DISPLAYTEXT parses up to |len| bytes from |*inp| as a DER-encoded X.509
 // DisplayText (RFC 5280), as described in |d2i_SAMPLE|.
 //
 // TODO(https://crbug.com/boringssl/354): This function currently also accepts
 // BER, but this will be removed in the future.
 //
 // TODO(https://crbug.com/boringssl/449): DisplayText's size limits are not
 // currently enforced.
 OPENSSL_EXPORT ASN1_STRING *d2i_DISPLAYTEXT(ASN1_STRING **out,
                                             const uint8_t **inp, long len);
 
 // i2d_DISPLAYTEXT marshals |in| as a DER-encoded X.509 DisplayText (RFC 5280),
 // as described in |i2d_SAMPLE|.
 OPENSSL_EXPORT int i2d_DISPLAYTEXT(const ASN1_STRING *in, uint8_t **outp);
 
 // DISPLAYTEXT is an |ASN1_ITEM| whose ASN.1 type is X.509 DisplayText (RFC
 // 5280) and C type is |ASN1_STRING*|.
 DECLARE_ASN1_ITEM(DISPLAYTEXT)
 
 
 // Bit strings.
 //
 // An ASN.1 BIT STRING type represents a string of bits. The string may not
 // necessarily be a whole number of bytes. BIT STRINGs occur in ASN.1 structures
 // in several forms:
 //
 // Some BIT STRINGs represent a bitmask of named bits, such as the X.509 key
 // usage extension in RFC 5280, section 4.2.1.3. For such bit strings, DER
 // imposes an additional restriction that trailing zero bits are removed. Some
 // functions like |ASN1_BIT_STRING_set_bit| help in maintaining this.
 //
 // Other BIT STRINGs are arbitrary strings of bits used as identifiers and do
 // not have this constraint, such as the X.509 issuerUniqueID field.
 //
 // Finally, some structures use BIT STRINGs as a container for byte strings. For
 // example, the signatureValue field in X.509 and the subjectPublicKey field in
 // SubjectPublicKeyInfo are defined as BIT STRINGs with a value specific to the
 // AlgorithmIdentifier. While some unknown algorithm could choose to store
 // arbitrary bit strings, all supported algorithms use a byte string, with bit
 // order matching the DER encoding. Callers interpreting a BIT STRING as a byte
 // string should use |ASN1_BIT_STRING_num_bytes| instead of |ASN1_STRING_length|
 // and reject bit strings that are not a whole number of bytes.
 //
 // This library represents BIT STRINGs as |ASN1_STRING|s with type
 // |V_ASN1_BIT_STRING|. The data contains the encoded form of the BIT STRING,
 // including any padding bits added to round to a whole number of bytes, but
 // excluding the leading byte containing the number of padding bits. If
 // |ASN1_STRING_FLAG_BITS_LEFT| is set, the bottom three bits contains the
 // number of padding bits. For example, DER encodes the BIT STRING {1, 0} as
 // {0x06, 0x80 = 0b10_000000}. The |ASN1_STRING| representation has data of
 // {0x80} and flags of ASN1_STRING_FLAG_BITS_LEFT | 6. If
 // |ASN1_STRING_FLAG_BITS_LEFT| is unset, trailing zero bits are implicitly
 // removed. Callers should not rely this representation when constructing bit
 // strings. The padding bits in the |ASN1_STRING| data must be zero.
 
 // ASN1_BIT_STRING_new calls |ASN1_STRING_type_new| with |V_ASN1_BIT_STRING|.
 OPENSSL_EXPORT ASN1_BIT_STRING *ASN1_BIT_STRING_new(void);
 
 // ASN1_BIT_STRING_free calls |ASN1_STRING_free|.
 OPENSSL_EXPORT void ASN1_BIT_STRING_free(ASN1_BIT_STRING *str);
 
 // d2i_ASN1_BIT_STRING parses up to |len| bytes from |*inp| as a DER-encoded
 // ASN.1 BIT STRING, as described in |d2i_SAMPLE|.
 OPENSSL_EXPORT ASN1_BIT_STRING *d2i_ASN1_BIT_STRING(ASN1_BIT_STRING **out,
                                                     const uint8_t **inp,
                                                     long len);
 
 // i2d_ASN1_BIT_STRING marshals |in| as a DER-encoded ASN.1 BIT STRING, as
 // described in |i2d_SAMPLE|.
 OPENSSL_EXPORT int i2d_ASN1_BIT_STRING(const ASN1_BIT_STRING *in,
                                        uint8_t **outp);
 
 // c2i_ASN1_BIT_STRING decodes |len| bytes from |*inp| as the contents of a
 // DER-encoded BIT STRING, excluding the tag and length. It behaves like
 // |d2i_SAMPLE| except, on success, it always consumes all |len| bytes.
 OPENSSL_EXPORT ASN1_BIT_STRING *c2i_ASN1_BIT_STRING(ASN1_BIT_STRING **out,
                                                     const uint8_t **inp,
                                                     long len);
 
 // i2c_ASN1_BIT_STRING encodes |in| as the contents of a DER-encoded BIT STRING,
 // excluding the tag and length. If |outp| is non-NULL, it writes the result to
 // |*outp|, advances |*outp| just past the output, and returns the number of
 // bytes written. |*outp| must have space available for the result. If |outp| is
 // NULL, it returns the number of bytes without writing anything. On error, it
 // returns a value <= 0.
 //
 // Note this function differs slightly from |i2d_SAMPLE|. If |outp| is non-NULL
 // and |*outp| is NULL, it does not allocate a new buffer.
 //
 // TODO(davidben): This function currently returns zero on error instead of -1,
 // but it is also mostly infallible. I've currently documented <= 0 to suggest
 // callers work with both.
 OPENSSL_EXPORT int i2c_ASN1_BIT_STRING(const ASN1_BIT_STRING *in,
                                        uint8_t **outp);
 
 // ASN1_BIT_STRING is an |ASN1_ITEM| with ASN.1 type BIT STRING and C type
 // |ASN1_BIT_STRING*|.
 DECLARE_ASN1_ITEM(ASN1_BIT_STRING)
 
 // ASN1_BIT_STRING_num_bytes computes the length of |str| in bytes. If |str|'s
 // bit length is a multiple of 8, it sets |*out| to the byte length and returns
 // one. Otherwise, it returns zero.
 //
 // This function may be used with |ASN1_STRING_get0_data| to interpret |str| as
 // a byte string.
 OPENSSL_EXPORT int ASN1_BIT_STRING_num_bytes(const ASN1_BIT_STRING *str,
                                              size_t *out);
 
 // ASN1_BIT_STRING_set calls |ASN1_STRING_set|. It leaves flags unchanged, so
 // the caller must set the number of unused bits.
 //
 // TODO(davidben): Maybe it should? Wrapping a byte string in a bit string is a
 // common use case.
 OPENSSL_EXPORT int ASN1_BIT_STRING_set(ASN1_BIT_STRING *str,
                                        const unsigned char *d,
                                        ossl_ssize_t length);
 
 // ASN1_BIT_STRING_set_bit sets bit |n| of |str| to one if |value| is non-zero
 // and zero if |value| is zero, resizing |str| as needed. It then truncates
 // trailing zeros in |str| to align with the DER represention for a bit string
 // with named bits. It returns one on success and zero on error. |n| is indexed
 // beginning from zero.
 OPENSSL_EXPORT int ASN1_BIT_STRING_set_bit(ASN1_BIT_STRING *str, int n,
                                            int value);
 
 // ASN1_BIT_STRING_get_bit returns one if bit |n| of |a| is in bounds and set,
 // and zero otherwise. |n| is indexed beginning from zero.
 OPENSSL_EXPORT int ASN1_BIT_STRING_get_bit(const ASN1_BIT_STRING *str, int n);
 
 // ASN1_BIT_STRING_check returns one if |str| only contains bits that are set in
 // the |flags_len| bytes pointed by |flags|. Otherwise it returns zero. Bits in
 // |flags| are arranged according to the DER representation, so bit 0
 // corresponds to the MSB of |flags[0]|.
 OPENSSL_EXPORT int ASN1_BIT_STRING_check(const ASN1_BIT_STRING *str,
                                          const unsigned char *flags,
                                          int flags_len);
 
 
 // Integers and enumerated values.
 //
 // INTEGER and ENUMERATED values are represented as |ASN1_STRING|s where the
 // data contains the big-endian encoding of the absolute value of the integer.
 // The sign bit is encoded in the type: non-negative values have a type of
 // |V_ASN1_INTEGER| or |V_ASN1_ENUMERATED|, while negative values have a type of
 // |V_ASN1_NEG_INTEGER| or |V_ASN1_NEG_ENUMERATED|. Note this differs from DER's
 // two's complement representation.
 //
 // The data in the |ASN1_STRING| may not have leading zeros. Note this means
 // zero is represented as the empty string. Parsing functions will never return
 // invalid representations. If an invalid input is constructed, the marshaling
 // functions will skip leading zeros, however other functions, such as
 // |ASN1_INTEGER_cmp| or |ASN1_INTEGER_get|, may not return the correct result.
 
 DEFINE_STACK_OF(ASN1_INTEGER)
 
 // ASN1_INTEGER_new calls |ASN1_STRING_type_new| with |V_ASN1_INTEGER|. The
 // resulting object has value zero.
 OPENSSL_EXPORT ASN1_INTEGER *ASN1_INTEGER_new(void);
 
 // ASN1_INTEGER_free calls |ASN1_STRING_free|.
 OPENSSL_EXPORT void ASN1_INTEGER_free(ASN1_INTEGER *str);
 
 // ASN1_INTEGER_dup calls |ASN1_STRING_dup|.
 OPENSSL_EXPORT ASN1_INTEGER *ASN1_INTEGER_dup(const ASN1_INTEGER *x);
 
 // d2i_ASN1_INTEGER parses up to |len| bytes from |*inp| as a DER-encoded
 // ASN.1 INTEGER, as described in |d2i_SAMPLE|.
 OPENSSL_EXPORT ASN1_INTEGER *d2i_ASN1_INTEGER(ASN1_INTEGER **out,
                                               const uint8_t **inp, long len);
 
 // i2d_ASN1_INTEGER marshals |in| as a DER-encoded ASN.1 INTEGER, as
 // described in |i2d_SAMPLE|.
 OPENSSL_EXPORT int i2d_ASN1_INTEGER(const ASN1_INTEGER *in, uint8_t **outp);
 
 // c2i_ASN1_INTEGER decodes |len| bytes from |*inp| as the contents of a
 // DER-encoded INTEGER, excluding the tag and length. It behaves like
 // |d2i_SAMPLE| except, on success, it always consumes all |len| bytes.
 OPENSSL_EXPORT ASN1_INTEGER *c2i_ASN1_INTEGER(ASN1_INTEGER **in,
                                               const uint8_t **outp, long len);
 
 // i2c_ASN1_INTEGER encodes |in| as the contents of a DER-encoded INTEGER,
 // excluding the tag and length. If |outp| is non-NULL, it writes the result to
 // |*outp|, advances |*outp| just past the output, and returns the number of
 // bytes written. |*outp| must have space available for the result. If |outp| is
 // NULL, it returns the number of bytes without writing anything. On error, it
 // returns a value <= 0.
 //
 // Note this function differs slightly from |i2d_SAMPLE|. If |outp| is non-NULL
 // and |*outp| is NULL, it does not allocate a new buffer.
 //
 // TODO(davidben): This function currently returns zero on error instead of -1,
 // but it is also mostly infallible. I've currently documented <= 0 to suggest
 // callers work with both.
 OPENSSL_EXPORT int i2c_ASN1_INTEGER(const ASN1_INTEGER *in, uint8_t **outp);
 
 // ASN1_INTEGER is an |ASN1_ITEM| with ASN.1 type INTEGER and C type
 // |ASN1_INTEGER*|.
 DECLARE_ASN1_ITEM(ASN1_INTEGER)
 
 // ASN1_INTEGER_set_uint64 sets |a| to an INTEGER with value |v|. It returns one
 // on success and zero on error.
 OPENSSL_EXPORT int ASN1_INTEGER_set_uint64(ASN1_INTEGER *out, uint64_t v);
 
 // ASN1_INTEGER_set_int64 sets |a| to an INTEGER with value |v|. It returns one
 // on success and zero on error.
 OPENSSL_EXPORT int ASN1_INTEGER_set_int64(ASN1_INTEGER *out, int64_t v);
 
 // ASN1_INTEGER_get_uint64 converts |a| to a |uint64_t|. On success, it returns
 // one and sets |*out| to the result. If |a| did not fit or has the wrong type,
 // it returns zero.
 OPENSSL_EXPORT int ASN1_INTEGER_get_uint64(uint64_t *out,
                                            const ASN1_INTEGER *a);
 
 // ASN1_INTEGER_get_int64 converts |a| to a |int64_t|. On success, it returns
 // one and sets |*out| to the result. If |a| did not fit or has the wrong type,
 // it returns zero.
 OPENSSL_EXPORT int ASN1_INTEGER_get_int64(int64_t *out, const ASN1_INTEGER *a);
 
 // BN_to_ASN1_INTEGER sets |ai| to an INTEGER with value |bn| and returns |ai|
 // on success or NULL or error. If |ai| is NULL, it returns a newly-allocated
 // |ASN1_INTEGER| on success instead, which the caller must release with
 // |ASN1_INTEGER_free|.
 OPENSSL_EXPORT ASN1_INTEGER *BN_to_ASN1_INTEGER(const BIGNUM *bn,
                                                 ASN1_INTEGER *ai);
 
 // ASN1_INTEGER_to_BN sets |bn| to the value of |ai| and returns |bn| on success
 // or NULL or error. If |bn| is NULL, it returns a newly-allocated |BIGNUM| on
 // success instead, which the caller must release with |BN_free|.
 OPENSSL_EXPORT BIGNUM *ASN1_INTEGER_to_BN(const ASN1_INTEGER *ai, BIGNUM *bn);
 
 // ASN1_INTEGER_cmp compares the values of |x| and |y|. It returns an integer
 // equal to, less than, or greater than zero if |x| is equal to, less than, or
 // greater than |y|, respectively.
 OPENSSL_EXPORT int ASN1_INTEGER_cmp(const ASN1_INTEGER *x,
                                     const ASN1_INTEGER *y);
 
 // ASN1_ENUMERATED_new calls |ASN1_STRING_type_new| with |V_ASN1_ENUMERATED|.
 // The resulting object has value zero.
 OPENSSL_EXPORT ASN1_ENUMERATED *ASN1_ENUMERATED_new(void);
 
 // ASN1_ENUMERATED_free calls |ASN1_STRING_free|.
 OPENSSL_EXPORT void ASN1_ENUMERATED_free(ASN1_ENUMERATED *str);
 
 // d2i_ASN1_ENUMERATED parses up to |len| bytes from |*inp| as a DER-encoded
 // ASN.1 ENUMERATED, as described in |d2i_SAMPLE|.
 OPENSSL_EXPORT ASN1_ENUMERATED *d2i_ASN1_ENUMERATED(ASN1_ENUMERATED **out,
                                                     const uint8_t **inp,
                                                     long len);
 
 // i2d_ASN1_ENUMERATED marshals |in| as a DER-encoded ASN.1 ENUMERATED, as
 // described in |i2d_SAMPLE|.
 OPENSSL_EXPORT int i2d_ASN1_ENUMERATED(const ASN1_ENUMERATED *in,
                                        uint8_t **outp);
 
 // ASN1_ENUMERATED is an |ASN1_ITEM| with ASN.1 type ENUMERATED and C type
 // |ASN1_ENUMERATED*|.
 DECLARE_ASN1_ITEM(ASN1_ENUMERATED)
 
 // ASN1_ENUMERATED_set_uint64 sets |a| to an ENUMERATED with value |v|. It
 // returns one on success and zero on error.
 OPENSSL_EXPORT int ASN1_ENUMERATED_set_uint64(ASN1_ENUMERATED *out, uint64_t v);
 
 // ASN1_ENUMERATED_set_int64 sets |a| to an ENUMERATED with value |v|. It
 // returns one on success and zero on error.
 OPENSSL_EXPORT int ASN1_ENUMERATED_set_int64(ASN1_ENUMERATED *out, int64_t v);
 
 // ASN1_ENUMERATED_get_uint64 converts |a| to a |uint64_t|. On success, it
 // returns one and sets |*out| to the result. If |a| did not fit or has the
 // wrong type, it returns zero.
 OPENSSL_EXPORT int ASN1_ENUMERATED_get_uint64(uint64_t *out,
                                               const ASN1_ENUMERATED *a);
 
 // ASN1_ENUMERATED_get_int64 converts |a| to a |int64_t|. On success, it
 // returns one and sets |*out| to the result. If |a| did not fit or has the
 // wrong type, it returns zero.
 OPENSSL_EXPORT int ASN1_ENUMERATED_get_int64(int64_t *out,
                                              const ASN1_ENUMERATED *a);
 
 // BN_to_ASN1_ENUMERATED sets |ai| to an ENUMERATED with value |bn| and returns
 // |ai| on success or NULL or error. If |ai| is NULL, it returns a
 // newly-allocated |ASN1_ENUMERATED| on success instead, which the caller must
 // release with |ASN1_ENUMERATED_free|.
 OPENSSL_EXPORT ASN1_ENUMERATED *BN_to_ASN1_ENUMERATED(const BIGNUM *bn,
                                                       ASN1_ENUMERATED *ai);
 
 // ASN1_ENUMERATED_to_BN sets |bn| to the value of |ai| and returns |bn| on
 // success or NULL or error. If |bn| is NULL, it returns a newly-allocated
 // |BIGNUM| on success instead, which the caller must release with |BN_free|.
 OPENSSL_EXPORT BIGNUM *ASN1_ENUMERATED_to_BN(const ASN1_ENUMERATED *ai,
                                              BIGNUM *bn);
 
 
 // Time.
 //
 // GeneralizedTime and UTCTime values are represented as |ASN1_STRING|s. The
 // type field is |V_ASN1_GENERALIZEDTIME| or |V_ASN1_UTCTIME|, respectively. The
 // data field contains the DER encoding of the value. For example, the UNIX
 // epoch would be "19700101000000Z" for a GeneralizedTime and "700101000000Z"
 // for a UTCTime.
 //
 // ASN.1 does not define how to interpret UTCTime's two-digit year. RFC 5280
 // defines it as a range from 1950 to 2049 for X.509. The library uses the
 // RFC 5280 interpretation. It does not currently enforce the restrictions from
 // BER, and the additional restrictions from RFC 5280, but future versions may.
 // Callers should not rely on fractional seconds and non-UTC time zones.
 //
 // The |ASN1_TIME| typedef is a multi-string representing the X.509 Time type,
 // which is a CHOICE of GeneralizedTime and UTCTime, using UTCTime when the
 // value is in range.
 
 // ASN1_UTCTIME_new calls |ASN1_STRING_type_new| with |V_ASN1_UTCTIME|. The
 // resulting object contains empty contents and must be initialized to be a
 // valid UTCTime.
 OPENSSL_EXPORT ASN1_UTCTIME *ASN1_UTCTIME_new(void);
 
 // ASN1_UTCTIME_free calls |ASN1_STRING_free|.
 OPENSSL_EXPORT void ASN1_UTCTIME_free(ASN1_UTCTIME *str);
 
 // d2i_ASN1_UTCTIME parses up to |len| bytes from |*inp| as a DER-encoded
 // ASN.1 UTCTime, as described in |d2i_SAMPLE|.
 //
 // TODO(https://crbug.com/boringssl/354): This function currently also accepts
 // BER, but this will be removed in the future.
 OPENSSL_EXPORT ASN1_UTCTIME *d2i_ASN1_UTCTIME(ASN1_UTCTIME **out,
                                               const uint8_t **inp, long len);
 
 // i2d_ASN1_UTCTIME marshals |in| as a DER-encoded ASN.1 UTCTime, as
 // described in |i2d_SAMPLE|.
 OPENSSL_EXPORT int i2d_ASN1_UTCTIME(const ASN1_UTCTIME *in, uint8_t **outp);
 
 // ASN1_UTCTIME is an |ASN1_ITEM| with ASN.1 type UTCTime and C type
 // |ASN1_UTCTIME*|.
 DECLARE_ASN1_ITEM(ASN1_UTCTIME)
 
 // ASN1_UTCTIME_check returns one if |a| is a valid UTCTime and zero otherwise.
 OPENSSL_EXPORT int ASN1_UTCTIME_check(const ASN1_UTCTIME *a);
 
 // ASN1_UTCTIME_set represents |posix_time| as a UTCTime and writes the result
 // to |s|. It returns |s| on success and NULL on error. If |s| is NULL, it
 // returns a newly-allocated |ASN1_UTCTIME| instead.
 //
 // Note this function may fail if the time is out of range for UTCTime.
 OPENSSL_EXPORT ASN1_UTCTIME *ASN1_UTCTIME_set(ASN1_UTCTIME *s,
                                               int64_t posix_time);
 
 // ASN1_UTCTIME_adj adds |offset_day| days and |offset_sec| seconds to
 // |posix_time| and writes the result to |s| as a UTCTime. It returns |s| on
 // success and NULL on error. If |s| is NULL, it returns a newly-allocated
 // |ASN1_UTCTIME| instead.
 //
 // Note this function may fail if the time overflows or is out of range for
 // UTCTime.
 OPENSSL_EXPORT ASN1_UTCTIME *ASN1_UTCTIME_adj(ASN1_UTCTIME *s,
                                               int64_t posix_time,
                                               int offset_day, long offset_sec);
 
 // ASN1_UTCTIME_set_string sets |s| to a UTCTime whose contents are a copy of
 // |str|. It returns one on success and zero on error or if |str| is not a valid
 // UTCTime.
 //
 // If |s| is NULL, this function validates |str| without copying it.
 OPENSSL_EXPORT int ASN1_UTCTIME_set_string(ASN1_UTCTIME *s, const char *str);
 
 // ASN1_GENERALIZEDTIME_new calls |ASN1_STRING_type_new| with
 // |V_ASN1_GENERALIZEDTIME|. The resulting object contains empty contents and
 // must be initialized to be a valid GeneralizedTime.
 OPENSSL_EXPORT ASN1_GENERALIZEDTIME *ASN1_GENERALIZEDTIME_new(void);
 
 // ASN1_GENERALIZEDTIME_free calls |ASN1_STRING_free|.
 OPENSSL_EXPORT void ASN1_GENERALIZEDTIME_free(ASN1_GENERALIZEDTIME *str);
 
 // d2i_ASN1_GENERALIZEDTIME parses up to |len| bytes from |*inp| as a
 // DER-encoded ASN.1 GeneralizedTime, as described in |d2i_SAMPLE|.
 OPENSSL_EXPORT ASN1_GENERALIZEDTIME *d2i_ASN1_GENERALIZEDTIME(
     ASN1_GENERALIZEDTIME **out, const uint8_t **inp, long len);
 
 // i2d_ASN1_GENERALIZEDTIME marshals |in| as a DER-encoded ASN.1
 // GeneralizedTime, as described in |i2d_SAMPLE|.
 OPENSSL_EXPORT int i2d_ASN1_GENERALIZEDTIME(const ASN1_GENERALIZEDTIME *in,
                                             uint8_t **outp);
 
 // ASN1_GENERALIZEDTIME is an |ASN1_ITEM| with ASN.1 type GeneralizedTime and C
 // type |ASN1_GENERALIZEDTIME*|.
 DECLARE_ASN1_ITEM(ASN1_GENERALIZEDTIME)
 
 // ASN1_GENERALIZEDTIME_check returns one if |a| is a valid GeneralizedTime and
 // zero otherwise.
 OPENSSL_EXPORT int ASN1_GENERALIZEDTIME_check(const ASN1_GENERALIZEDTIME *a);
 
 // ASN1_GENERALIZEDTIME_set represents |posix_time| as a GeneralizedTime and
 // writes the result to |s|. It returns |s| on success and NULL on error. If |s|
 // is NULL, it returns a newly-allocated |ASN1_GENERALIZEDTIME| instead.
 //
 // Note this function may fail if the time is out of range for GeneralizedTime.
 OPENSSL_EXPORT ASN1_GENERALIZEDTIME *ASN1_GENERALIZEDTIME_set(
     ASN1_GENERALIZEDTIME *s, int64_t posix_time);
 
 // ASN1_GENERALIZEDTIME_adj adds |offset_day| days and |offset_sec| seconds to
 // |posix_time| and writes the result to |s| as a GeneralizedTime. It returns
 // |s| on success and NULL on error. If |s| is NULL, it returns a
 // newly-allocated |ASN1_GENERALIZEDTIME| instead.
 //
 // Note this function may fail if the time overflows or is out of range for
 // GeneralizedTime.
 OPENSSL_EXPORT ASN1_GENERALIZEDTIME *ASN1_GENERALIZEDTIME_adj(
     ASN1_GENERALIZEDTIME *s, int64_t posix_time, int offset_day,
     long offset_sec);
 
 // ASN1_GENERALIZEDTIME_set_string sets |s| to a GeneralizedTime whose contents
 // are a copy of |str|. It returns one on success and zero on error or if |str|
 // is not a valid GeneralizedTime.
 //
 // If |s| is NULL, this function validates |str| without copying it.
 OPENSSL_EXPORT int ASN1_GENERALIZEDTIME_set_string(ASN1_GENERALIZEDTIME *s,
                                                    const char *str);
 
 // B_ASN1_TIME is a bitmask of types allowed in an X.509 Time.
 #define B_ASN1_TIME (B_ASN1_UTCTIME | B_ASN1_GENERALIZEDTIME)
 
 // ASN1_TIME_new returns a newly-allocated |ASN1_TIME| with type -1, or NULL on
 // error. The resulting |ASN1_TIME| is not a valid X.509 Time until initialized
 // with a value.
 OPENSSL_EXPORT ASN1_TIME *ASN1_TIME_new(void);
 
 // ASN1_TIME_free releases memory associated with |str|.
 OPENSSL_EXPORT void ASN1_TIME_free(ASN1_TIME *str);
 
 // d2i_ASN1_TIME parses up to |len| bytes from |*inp| as a DER-encoded X.509
 // Time (RFC 5280), as described in |d2i_SAMPLE|.
 //
 // TODO(https://crbug.com/boringssl/354): This function currently also accepts
 // BER, but this will be removed in the future.
 OPENSSL_EXPORT ASN1_TIME *d2i_ASN1_TIME(ASN1_TIME **out, const uint8_t **inp,
                                         long len);
 
 // i2d_ASN1_TIME marshals |in| as a DER-encoded X.509 Time (RFC 5280), as
 // described in |i2d_SAMPLE|.
 OPENSSL_EXPORT int i2d_ASN1_TIME(const ASN1_TIME *in, uint8_t **outp);
 
 // ASN1_TIME is an |ASN1_ITEM| whose ASN.1 type is X.509 Time (RFC 5280) and C
 // type is |ASN1_TIME*|.
 DECLARE_ASN1_ITEM(ASN1_TIME)
 
 // ASN1_TIME_diff computes |to| - |from|. On success, it sets |*out_days| to the
 // difference in days, rounded towards zero, sets |*out_seconds| to the
 // remainder, and returns one. On error, it returns zero.
 //
 // If |from| is before |to|, both outputs will be <= 0, with at least one
 // negative. If |from| is after |to|, both will be >= 0, with at least one
 // positive. If they are equal, ignoring fractional seconds, both will be zero.
 //
 // Note this function may fail on overflow, or if |from| or |to| cannot be
 // decoded.
 OPENSSL_EXPORT int ASN1_TIME_diff(int *out_days, int *out_seconds,
                                   const ASN1_TIME *from, const ASN1_TIME *to);
 
 // ASN1_TIME_set_posix represents |posix_time| as a GeneralizedTime or UTCTime
 // and writes the result to |s|. As in RFC 5280, section 4.1.2.5, it uses
 // UTCTime when the time fits and GeneralizedTime otherwise. It returns |s| on
 // success and NULL on error. If |s| is NULL, it returns a newly-allocated
 // |ASN1_TIME| instead.
 //
 // Note this function may fail if the time is out of range for GeneralizedTime.
 OPENSSL_EXPORT ASN1_TIME *ASN1_TIME_set_posix(ASN1_TIME *s, int64_t posix_time);
 
 // ASN1_TIME_set is exactly the same as |ASN1_TIME_set_posix| but with a
 // time_t as input for compatibility.
 OPENSSL_EXPORT ASN1_TIME *ASN1_TIME_set(ASN1_TIME *s, time_t time);
 
 // ASN1_TIME_adj adds |offset_day| days and |offset_sec| seconds to
 // |posix_time| and writes the result to |s|. As in RFC 5280, section 4.1.2.5,
 // it uses UTCTime when the time fits and GeneralizedTime otherwise. It returns
 // |s| on success and NULL on error. If |s| is NULL, it returns a
 // newly-allocated |ASN1_GENERALIZEDTIME| instead.
 //
 // Note this function may fail if the time overflows or is out of range for
 // GeneralizedTime.
 OPENSSL_EXPORT ASN1_TIME *ASN1_TIME_adj(ASN1_TIME *s, int64_t posix_time,
                                         int offset_day, long offset_sec);
 
 // ASN1_TIME_check returns one if |t| is a valid UTCTime or GeneralizedTime, and
 // zero otherwise. |t|'s type determines which check is performed. This
 // function does not enforce that UTCTime was used when possible.
 OPENSSL_EXPORT int ASN1_TIME_check(const ASN1_TIME *t);
 
 // ASN1_TIME_to_generalizedtime converts |t| to a GeneralizedTime. If |out| is
 // NULL, it returns a newly-allocated |ASN1_GENERALIZEDTIME| on success, or NULL
 // on error. If |out| is non-NULL and |*out| is NULL, it additionally sets
 // |*out| to the result. If |out| and |*out| are non-NULL, it instead updates
 // the object pointed by |*out| and returns |*out| on success or NULL on error.
 OPENSSL_EXPORT ASN1_GENERALIZEDTIME *ASN1_TIME_to_generalizedtime(
     const ASN1_TIME *t, ASN1_GENERALIZEDTIME **out);
 
 // ASN1_TIME_set_string behaves like |ASN1_UTCTIME_set_string| if |str| is a
 // valid UTCTime, and |ASN1_GENERALIZEDTIME_set_string| if |str| is a valid
 // GeneralizedTime. If |str| is neither, it returns zero.
 OPENSSL_EXPORT int ASN1_TIME_set_string(ASN1_TIME *s, const char *str);
 
 // ASN1_TIME_set_string_X509 behaves like |ASN1_TIME_set_string| except it
 // additionally converts GeneralizedTime to UTCTime if it is in the range where
 // UTCTime is used. See RFC 5280, section 4.1.2.5.
 OPENSSL_EXPORT int ASN1_TIME_set_string_X509(ASN1_TIME *s, const char *str);
 
 // ASN1_TIME_to_time_t converts |t| to a time_t value in |out|. On
 // success, one is returned. On failure, zero is returned. This function
 // will fail if the time can not be represented in a time_t.
 OPENSSL_EXPORT int ASN1_TIME_to_time_t(const ASN1_TIME *t, time_t *out);
 
 // ASN1_TIME_to_posix converts |t| to a POSIX time value in |out|. On
 // success, one is returned. On failure, zero is returned.
 OPENSSL_EXPORT int ASN1_TIME_to_posix(const ASN1_TIME *t, int64_t *out);
 
 // ASN1_TIME_to_posix_nonstandard converts |t| to a POSIX time value in
 // |out|. It is exactly the same as |ASN1_TIME_to_posix| but allows for
 // non-standard four-digit timezone offsets on UTC times. On success, one is
 // returned. On failure, zero is returned. |ASN1_TIME_to_posix| should normally
 // be used instead of this function.
 OPENSSL_EXPORT int ASN1_TIME_to_posix_nonstandard(
     const ASN1_TIME *t, int64_t *out);
 
 // TODO(davidben): Expand and document function prototypes generated in macros.
 
 
 // NULL values.
 //
 // This library represents the ASN.1 NULL value by a non-NULL pointer to the
 // opaque type |ASN1_NULL|. An omitted OPTIONAL ASN.1 NULL value is a NULL
 // pointer. Unlike other pointer types, it is not necessary to free |ASN1_NULL|
 // pointers, but it is safe to do so.
 
 // ASN1_NULL_new returns an opaque, non-NULL pointer. It is safe to call
 // |ASN1_NULL_free| on the result, but not necessary.
 OPENSSL_EXPORT ASN1_NULL *ASN1_NULL_new(void);
 
 // ASN1_NULL_free does nothing.
 OPENSSL_EXPORT void ASN1_NULL_free(ASN1_NULL *null);
 
 // d2i_ASN1_NULL parses a DER-encoded ASN.1 NULL value from up to |len| bytes
 // at |*inp|, as described in |d2i_SAMPLE|.
 OPENSSL_EXPORT ASN1_NULL *d2i_ASN1_NULL(ASN1_NULL **out, const uint8_t **inp,
                                         long len);
 
 // i2d_ASN1_NULL marshals |in| as a DER-encoded ASN.1 NULL value, as described
 // in |i2d_SAMPLE|.
 OPENSSL_EXPORT int i2d_ASN1_NULL(const ASN1_NULL *in, uint8_t **outp);
 
 // ASN1_NULL is an |ASN1_ITEM| with ASN.1 type NULL and C type |ASN1_NULL*|.
 DECLARE_ASN1_ITEM(ASN1_NULL)
 
 
 // Object identifiers.
 //
 // An |ASN1_OBJECT| represents a ASN.1 OBJECT IDENTIFIER. See also obj.h for
 // additional functions relating to |ASN1_OBJECT|.
 //
 // TODO(davidben): What's the relationship between asn1.h and obj.h? Most of
 // obj.h deals with the large NID table, but then functions like |OBJ_get0_data|
 // or |OBJ_dup| are general |ASN1_OBJECT| functions.
 
 DEFINE_STACK_OF(ASN1_OBJECT)
 
 // ASN1_OBJECT_create returns a newly-allocated |ASN1_OBJECT| with |len| bytes
 // from |data| as the encoded OID, or NULL on error. |data| should contain the
 // DER-encoded identifier, excluding the tag and length.
 //
 // |nid| should be |NID_undef|. Passing a NID value that does not match |data|
 // will cause some functions to misbehave. |sn| and |ln| should be NULL. If
 // non-NULL, they are stored as short and long names, respectively, but these
 // values have no effect for |ASN1_OBJECT|s created through this function.
 //
 // TODO(davidben): Should we just ignore all those parameters? NIDs and names
 // are only relevant for |ASN1_OBJECT|s in the obj.h table.
 OPENSSL_EXPORT ASN1_OBJECT *ASN1_OBJECT_create(int nid, const uint8_t *data,
                                                size_t len, const char *sn,
                                                const char *ln);
 
 // ASN1_OBJECT_free releases memory associated with |a|. If |a| is a static
 // |ASN1_OBJECT|, returned from |OBJ_nid2obj|, this function does nothing.
 OPENSSL_EXPORT void ASN1_OBJECT_free(ASN1_OBJECT *a);
 
 // d2i_ASN1_OBJECT parses a DER-encoded ASN.1 OBJECT IDENTIFIER from up to |len|
 // bytes at |*inp|, as described in |d2i_SAMPLE|.
 OPENSSL_EXPORT ASN1_OBJECT *d2i_ASN1_OBJECT(ASN1_OBJECT **out,
                                             const uint8_t **inp, long len);
 
 // i2d_ASN1_OBJECT marshals |in| as a DER-encoded ASN.1 OBJECT IDENTIFIER, as
 // described in |i2d_SAMPLE|.
 OPENSSL_EXPORT int i2d_ASN1_OBJECT(const ASN1_OBJECT *in, uint8_t **outp);
 
 // c2i_ASN1_OBJECT decodes |len| bytes from |*inp| as the contents of a
 // DER-encoded OBJECT IDENTIFIER, excluding the tag and length. It behaves like
 // |d2i_SAMPLE| except, on success, it always consumes all |len| bytes.
 OPENSSL_EXPORT ASN1_OBJECT *c2i_ASN1_OBJECT(ASN1_OBJECT **out,
                                             const uint8_t **inp, long len);
 
 // ASN1_OBJECT is an |ASN1_ITEM| with ASN.1 type OBJECT IDENTIFIER and C type
 // |ASN1_OBJECT*|.
 DECLARE_ASN1_ITEM(ASN1_OBJECT)
 
 
 // Arbitrary elements.
 
 // An asn1_type_st (aka |ASN1_TYPE|) represents an arbitrary ASN.1 element,
 // typically used for ANY types. It contains a |type| field and a |value| union
 // dependent on |type|.
 //
 // WARNING: This struct has a complex representation. Callers must not construct
 // |ASN1_TYPE| values manually. Use |ASN1_TYPE_set| and |ASN1_TYPE_set1|
 // instead. Additionally, callers performing non-trivial operations on this type
 // are encouraged to use |CBS| and |CBB| from <openssl/bytestring.h>, and
 // convert to or from |ASN1_TYPE| with |d2i_ASN1_TYPE| or |i2d_ASN1_TYPE|.
 //
 // The |type| field corresponds to the tag of the ASN.1 element being
 // represented:
 //
 // If |type| is a |V_ASN1_*| constant for an ASN.1 string-like type, as defined
 // by |ASN1_STRING|, the tag matches the constant. |value| contains an
 // |ASN1_STRING| pointer (equivalently, one of the more specific typedefs). See
 // |ASN1_STRING| for details on the representation. Unlike |ASN1_STRING|,
 // |ASN1_TYPE| does not use the |V_ASN1_NEG| flag for negative INTEGER and
 // ENUMERATE values. For a negative value, the |ASN1_TYPE|'s |type| will be
 // |V_ASN1_INTEGER| or |V_ASN1_ENUMERATED|, but |value| will an |ASN1_STRING|
 // whose |type| is |V_ASN1_NEG_INTEGER| or |V_ASN1_NEG_ENUMERATED|.
 //
 // If |type| is |V_ASN1_OBJECT|, the tag is OBJECT IDENTIFIER and |value|
 // contains an |ASN1_OBJECT| pointer.
 //
 // If |type| is |V_ASN1_NULL|, the tag is NULL. |value| contains a NULL pointer.
 //
 // If |type| is |V_ASN1_BOOLEAN|, the tag is BOOLEAN. |value| contains an
 // |ASN1_BOOLEAN|.
 //
 // If |type| is |V_ASN1_SEQUENCE|, |V_ASN1_SET|, or |V_ASN1_OTHER|, the tag is
 // SEQUENCE, SET, or some arbitrary tag, respectively. |value| uses the
 // corresponding |ASN1_STRING| representation. Although any type may be
 // represented in |V_ASN1_OTHER|, the parser will always return the more
 // specific encoding when available.
 //
 // Other values of |type| do not represent a valid ASN.1 value, though
 // default-constructed objects may set |type| to -1. Such objects cannot be
 // serialized.
 struct asn1_type_st {
   int type;
   union {
     char *ptr;
     ASN1_BOOLEAN boolean;
     ASN1_STRING *asn1_string;
     ASN1_OBJECT *object;
     ASN1_INTEGER *integer;
     ASN1_ENUMERATED *enumerated;
     ASN1_BIT_STRING *bit_string;
     ASN1_OCTET_STRING *octet_string;
     ASN1_PRINTABLESTRING *printablestring;
     ASN1_T61STRING *t61string;
     ASN1_IA5STRING *ia5string;
     ASN1_GENERALSTRING *generalstring;
     ASN1_BMPSTRING *bmpstring;
     ASN1_UNIVERSALSTRING *universalstring;
     ASN1_UTCTIME *utctime;
     ASN1_GENERALIZEDTIME *generalizedtime;
     ASN1_VISIBLESTRING *visiblestring;
     ASN1_UTF8STRING *utf8string;
     // set and sequence are left complete and still contain the entire element.
     ASN1_STRING *set;
     ASN1_STRING *sequence;
     ASN1_VALUE *asn1_value;
   } value;
 };
 
 DEFINE_STACK_OF(ASN1_TYPE)
 
 // ASN1_TYPE_new returns a newly-allocated |ASN1_TYPE|, or NULL on allocation
 // failure. The resulting object has type -1 and must be initialized to be
 // a valid ANY value.
 OPENSSL_EXPORT ASN1_TYPE *ASN1_TYPE_new(void);
 
 // ASN1_TYPE_free releases memory associated with |a|.
 OPENSSL_EXPORT void ASN1_TYPE_free(ASN1_TYPE *a);
 
 // d2i_ASN1_TYPE parses up to |len| bytes from |*inp| as an ASN.1 value of any
 // type, as described in |d2i_SAMPLE|. Note this function only validates
 // primitive, universal types supported by this library. Values of type
 // |V_ASN1_SEQUENCE|, |V_ASN1_SET|, |V_ASN1_OTHER|, or an unsupported primitive
 // type must be validated by the caller when interpreting.
 //
 // TODO(https://crbug.com/boringssl/354): This function currently also accepts
 // BER, but this will be removed in the future.
 OPENSSL_EXPORT ASN1_TYPE *d2i_ASN1_TYPE(ASN1_TYPE **out, const uint8_t **inp,
                                         long len);
 
 // i2d_ASN1_TYPE marshals |in| as DER, as described in |i2d_SAMPLE|.
 OPENSSL_EXPORT int i2d_ASN1_TYPE(const ASN1_TYPE *in, uint8_t **outp);
 
 // ASN1_ANY is an |ASN1_ITEM| with ASN.1 type ANY and C type |ASN1_TYPE*|. Note
 // the |ASN1_ITEM| name and C type do not match.
 DECLARE_ASN1_ITEM(ASN1_ANY)
 
 // ASN1_TYPE_get returns the type of |a|, which will be one of the |V_ASN1_*|
 // constants, or zero if |a| is not fully initialized.
 OPENSSL_EXPORT int ASN1_TYPE_get(const ASN1_TYPE *a);
 
 // ASN1_TYPE_set sets |a| to an |ASN1_TYPE| of type |type| and value |value|,
 // releasing the previous contents of |a|.
 //
 // If |type| is |V_ASN1_BOOLEAN|, |a| is set to FALSE if |value| is NULL and
 // TRUE otherwise. If setting |a| to TRUE, |value| may be an invalid pointer,
 // such as (void*)1.
 //
 // If |type| is |V_ASN1_NULL|, |value| must be NULL.
 //
 // For other values of |type|, this function takes ownership of |value|, which
 // must point to an object of the corresponding type. See |ASN1_TYPE| for
 // details.
 OPENSSL_EXPORT void ASN1_TYPE_set(ASN1_TYPE *a, int type, void *value);
 
 // ASN1_TYPE_set1 behaves like |ASN1_TYPE_set| except it does not take ownership
 // of |value|. It returns one on success and zero on error.
 OPENSSL_EXPORT int ASN1_TYPE_set1(ASN1_TYPE *a, int type, const void *value);
 
 // ASN1_TYPE_cmp returns zero if |a| and |b| are equal and some non-zero value
 // otherwise. Note this function can only be used for equality checks, not an
 // ordering.
 OPENSSL_EXPORT int ASN1_TYPE_cmp(const ASN1_TYPE *a, const ASN1_TYPE *b);
 
 typedef STACK_OF(ASN1_TYPE) ASN1_SEQUENCE_ANY;
 
 // d2i_ASN1_SEQUENCE_ANY parses up to |len| bytes from |*inp| as a DER-encoded
 // ASN.1 SEQUENCE OF ANY structure, as described in |d2i_SAMPLE|. The resulting
 // |ASN1_SEQUENCE_ANY| owns its contents and thus must be released with
 // |sk_ASN1_TYPE_pop_free| and |ASN1_TYPE_free|, not |sk_ASN1_TYPE_free|.
 //
 // TODO(https://crbug.com/boringssl/354): This function currently also accepts
 // BER, but this will be removed in the future.
 OPENSSL_EXPORT ASN1_SEQUENCE_ANY *d2i_ASN1_SEQUENCE_ANY(ASN1_SEQUENCE_ANY **out,
                                                         const uint8_t **inp,
                                                         long len);
 
 // i2d_ASN1_SEQUENCE_ANY marshals |in| as a DER-encoded SEQUENCE OF ANY
 // structure, as described in |i2d_SAMPLE|.
 OPENSSL_EXPORT int i2d_ASN1_SEQUENCE_ANY(const ASN1_SEQUENCE_ANY *in,
                                          uint8_t **outp);
 
 // d2i_ASN1_SET_ANY parses up to |len| bytes from |*inp| as a DER-encoded ASN.1
 // SET OF ANY structure, as described in |d2i_SAMPLE|. The resulting
 // |ASN1_SEQUENCE_ANY| owns its contents and thus must be released with
 // |sk_ASN1_TYPE_pop_free| and |ASN1_TYPE_free|, not |sk_ASN1_TYPE_free|.
 //
 // TODO(https://crbug.com/boringssl/354): This function currently also accepts
 // BER, but this will be removed in the future.
 OPENSSL_EXPORT ASN1_SEQUENCE_ANY *d2i_ASN1_SET_ANY(ASN1_SEQUENCE_ANY **out,
                                                    const uint8_t **inp,
                                                    long len);
 
 // i2d_ASN1_SET_ANY marshals |in| as a DER-encoded SET OF ANY structure, as
 // described in |i2d_SAMPLE|.
 OPENSSL_EXPORT int i2d_ASN1_SET_ANY(const ASN1_SEQUENCE_ANY *in,
                                     uint8_t **outp);
 
 
 // Human-readable output.
 //
 // The following functions output types in some human-readable format. These
 // functions may be used for debugging and logging. However, the output should
 // not be consumed programmatically. They may be ambiguous or lose information.
 
 // ASN1_UTCTIME_print writes a human-readable representation of |a| to |out|. It
 // returns one on success and zero on error.
 OPENSSL_EXPORT int ASN1_UTCTIME_print(BIO *out, const ASN1_UTCTIME *a);
 
 // ASN1_GENERALIZEDTIME_print writes a human-readable representation of |a| to
 // |out|. It returns one on success and zero on error.
 OPENSSL_EXPORT int ASN1_GENERALIZEDTIME_print(BIO *out,
                                               const ASN1_GENERALIZEDTIME *a);
 
 // ASN1_TIME_print writes a human-readable representation of |a| to |out|. It
 // returns one on success and zero on error.
 OPENSSL_EXPORT int ASN1_TIME_print(BIO *out, const ASN1_TIME *a);
 
 // ASN1_STRING_print writes a human-readable representation of |str| to |out|.
 // It returns one on success and zero on error. Unprintable characters are
 // replaced with '.'.
 OPENSSL_EXPORT int ASN1_STRING_print(BIO *out, const ASN1_STRING *str);
 
 // The following flags must not collide with |XN_FLAG_*|.
 
 // ASN1_STRFLGS_ESC_2253 causes characters to be escaped as in RFC 2253, section
 // 2.4.
 #define ASN1_STRFLGS_ESC_2253 1ul
 
 // ASN1_STRFLGS_ESC_CTRL causes all control characters to be escaped.
 #define ASN1_STRFLGS_ESC_CTRL 2ul
 
 // ASN1_STRFLGS_ESC_MSB causes all characters above 127 to be escaped.
 #define ASN1_STRFLGS_ESC_MSB 4ul
 
 // ASN1_STRFLGS_ESC_QUOTE causes the string to be surrounded by quotes, rather
 // than using backslashes, when characters are escaped. Fewer characters will
 // require escapes in this case.
 #define ASN1_STRFLGS_ESC_QUOTE 8ul
 
 // ASN1_STRFLGS_UTF8_CONVERT causes the string to be encoded as UTF-8, with each
 // byte in the UTF-8 encoding treated as an individual character for purposes of
 // escape sequences. If not set, each Unicode codepoint in the string is treated
 // as a character, with wide characters escaped as "\Uxxxx" or "\Wxxxxxxxx".
 // Note this can be ambiguous if |ASN1_STRFLGS_ESC_*| are all unset. In that
 // case, backslashes are not escaped, but wide characters are.
 #define ASN1_STRFLGS_UTF8_CONVERT 0x10ul
 
 // ASN1_STRFLGS_IGNORE_TYPE causes the string type to be ignored. The
 // |ASN1_STRING| in-memory representation will be printed directly.
 #define ASN1_STRFLGS_IGNORE_TYPE 0x20ul
 
 // ASN1_STRFLGS_SHOW_TYPE causes the string type to be included in the output.
 #define ASN1_STRFLGS_SHOW_TYPE 0x40ul
 
 // ASN1_STRFLGS_DUMP_ALL causes all strings to be printed as a hexdump, using
 // RFC 2253 hexstring notation, such as "#0123456789ABCDEF".
 #define ASN1_STRFLGS_DUMP_ALL 0x80ul
 
 // ASN1_STRFLGS_DUMP_UNKNOWN behaves like |ASN1_STRFLGS_DUMP_ALL| but only
 // applies to values of unknown type. If unset, unknown values will print
 // their contents as single-byte characters with escape sequences.
 #define ASN1_STRFLGS_DUMP_UNKNOWN 0x100ul
 
 // ASN1_STRFLGS_DUMP_DER causes hexdumped strings (as determined by
 // |ASN1_STRFLGS_DUMP_ALL| or |ASN1_STRFLGS_DUMP_UNKNOWN|) to print the entire
 // DER element as in RFC 2253, rather than only the contents of the
 // |ASN1_STRING|.
 #define ASN1_STRFLGS_DUMP_DER 0x200ul
 
 // ASN1_STRFLGS_RFC2253 causes the string to be escaped as in RFC 2253,
 // additionally escaping control characters.
 #define ASN1_STRFLGS_RFC2253                                              \
   (ASN1_STRFLGS_ESC_2253 | ASN1_STRFLGS_ESC_CTRL | ASN1_STRFLGS_ESC_MSB | \
    ASN1_STRFLGS_UTF8_CONVERT | ASN1_STRFLGS_DUMP_UNKNOWN |                \
    ASN1_STRFLGS_DUMP_DER)
 
 // ASN1_STRING_print_ex writes a human-readable representation of |str| to
 // |out|. It returns the number of bytes written on success and -1 on error. If
 // |out| is NULL, it returns the number of bytes it would have written, without
 // writing anything.
 //
 // The |flags| should be a combination of combination of |ASN1_STRFLGS_*|
 // constants. See the documentation for each flag for how it controls the
 // output. If unsure, use |ASN1_STRFLGS_RFC2253|.
 OPENSSL_EXPORT int ASN1_STRING_print_ex(BIO *out, const ASN1_STRING *str,
                                         unsigned long flags);
 
 // ASN1_STRING_print_ex_fp behaves like |ASN1_STRING_print_ex| but writes to a
 // |FILE| rather than a |BIO|.
 OPENSSL_EXPORT int ASN1_STRING_print_ex_fp(FILE *fp, const ASN1_STRING *str,
                                            unsigned long flags);
 
 // i2a_ASN1_INTEGER writes a human-readable representation of |a| to |bp|. It
 // returns the number of bytes written on success, or a negative number on
 // error. On error, this function may have written a partial output to |bp|.
 OPENSSL_EXPORT int i2a_ASN1_INTEGER(BIO *bp, const ASN1_INTEGER *a);
 
 // i2a_ASN1_ENUMERATED writes a human-readable representation of |a| to |bp|. It
 // returns the number of bytes written on success, or a negative number on
 // error. On error, this function may have written a partial output to |bp|.
 OPENSSL_EXPORT int i2a_ASN1_ENUMERATED(BIO *bp, const ASN1_ENUMERATED *a);
 
 // i2a_ASN1_OBJECT writes a human-readable representation of |a| to |bp|. It
 // returns the number of bytes written on success, or a negative number on
 // error. On error, this function may have written a partial output to |bp|.
 OPENSSL_EXPORT int i2a_ASN1_OBJECT(BIO *bp, const ASN1_OBJECT *a);
 
 // i2a_ASN1_STRING writes a text representation of |a|'s contents to |bp|. It
 // returns the number of bytes written on success, or a negative number on
 // error. On error, this function may have written a partial output to |bp|.
 // |type| is ignored.
 //
 // This function does not decode |a| into a Unicode string. It only hex-encodes
 // the internal representation of |a|. This is suitable for printing an OCTET
 // STRING, but may not be human-readable for any other string type.
 OPENSSL_EXPORT int i2a_ASN1_STRING(BIO *bp, const ASN1_STRING *a, int type);
 
 // i2t_ASN1_OBJECT calls |OBJ_obj2txt| with |always_return_oid| set to zero.
 OPENSSL_EXPORT int i2t_ASN1_OBJECT(char *buf, int buf_len,
                                    const ASN1_OBJECT *a);
 
 
 // Low-level encoding functions.
 
 // ASN1_get_object parses a BER element from up to |max_len| bytes at |*inp|. It
 // returns |V_ASN1_CONSTRUCTED| if it successfully parsed a constructed element,
 // zero if it successfully parsed a primitive element, and 0x80 on error. On
 // success, it additionally advances |*inp| to the element body, sets
 // |*out_length|, |*out_tag|, and |*out_class| to the element's length, tag
 // number, and tag class, respectively,
 //
 // Unlike OpenSSL, this function only supports DER. Indefinite and non-minimal
 // lengths are rejected.
 //
 // This function is difficult to use correctly. Use |CBS_get_asn1| and related
 // functions from bytestring.h.
 OPENSSL_EXPORT int ASN1_get_object(const unsigned char **inp, long *out_length,
                                    int *out_tag, int *out_class, long max_len);
 
 // ASN1_put_object writes the header for a DER or BER element to |*outp| and
 // advances |*outp| by the number of bytes written. The caller is responsible
 // for ensuring |*outp| has enough space for the output. The header describes an
 // element with length |length|, tag number |tag|, and class |xclass|. |xclass|
 // should be one of the |V_ASN1_*| tag class constants. The element is primitive
 // if |constructed| is zero and constructed if it is one or two. If
 // |constructed| is two, |length| is ignored and the element uses
 // indefinite-length encoding.
 //
 // Use |CBB_add_asn1| instead.
 OPENSSL_EXPORT void ASN1_put_object(unsigned char **outp, int constructed,
                                     int length, int tag, int xclass);
 
 // ASN1_put_eoc writes two zero bytes to |*outp|, advances |*outp| to point past
 // those bytes, and returns two.
 //
 // Use definite-length encoding instead.
 OPENSSL_EXPORT int ASN1_put_eoc(unsigned char **outp);
 
 // ASN1_object_size returns the number of bytes needed to encode a DER or BER
 // value with length |length| and tag number |tag|, or -1 on error. |tag| should
 // not include the constructed bit or tag class. If |constructed| is zero or
 // one, the result uses a definite-length encoding with minimally-encoded
 // length, as in DER. If |constructed| is two, the result uses BER
 // indefinite-length encoding.
 //
 // Use |CBB_add_asn1| instead.
 OPENSSL_EXPORT int ASN1_object_size(int constructed, int length, int tag);
 
 
 // Function declaration macros.
 //
 // The following macros declare functions for ASN.1 types. Prefer writing the
 // prototypes directly. Particularly when |type|, |itname|, or |name| differ,
 // the macros can be difficult to understand.
 
 #define DECLARE_ASN1_FUNCTIONS(type) DECLARE_ASN1_FUNCTIONS_name(type, type)
 
 #define DECLARE_ASN1_ALLOC_FUNCTIONS(type) \
   DECLARE_ASN1_ALLOC_FUNCTIONS_name(type, type)
 
 #define DECLARE_ASN1_FUNCTIONS_name(type, name) \
   DECLARE_ASN1_ALLOC_FUNCTIONS_name(type, name) \
   DECLARE_ASN1_ENCODE_FUNCTIONS(type, name, name)
 
 #define DECLARE_ASN1_FUNCTIONS_fname(type, itname, name) \
   DECLARE_ASN1_ALLOC_FUNCTIONS_name(type, name)          \
   DECLARE_ASN1_ENCODE_FUNCTIONS(type, itname, name)
 
 #define DECLARE_ASN1_ENCODE_FUNCTIONS(type, itname, name)             \
   OPENSSL_EXPORT type *d2i_##name(type **a, const unsigned char **in, \
                                   long len);                          \
   OPENSSL_EXPORT int i2d_##name(type *a, unsigned char **out);        \
   DECLARE_ASN1_ITEM(itname)
 
 #define DECLARE_ASN1_ENCODE_FUNCTIONS_const(type, name)               \
   OPENSSL_EXPORT type *d2i_##name(type **a, const unsigned char **in, \
                                   long len);                          \
   OPENSSL_EXPORT int i2d_##name(const type *a, unsigned char **out);  \
   DECLARE_ASN1_ITEM(name)
 
 #define DECLARE_ASN1_FUNCTIONS_const(name) \
   DECLARE_ASN1_ALLOC_FUNCTIONS(name)       \
   DECLARE_ASN1_ENCODE_FUNCTIONS_const(name, name)
 
 #define DECLARE_ASN1_ALLOC_FUNCTIONS_name(type, name) \
   OPENSSL_EXPORT type *name##_new(void);              \
   OPENSSL_EXPORT void name##_free(type *a);
 
 
 // Deprecated functions.
 
 // ASN1_STRING_set_default_mask does nothing.
 OPENSSL_EXPORT void ASN1_STRING_set_default_mask(unsigned long mask);
 
 // ASN1_STRING_set_default_mask_asc returns one.
 OPENSSL_EXPORT int ASN1_STRING_set_default_mask_asc(const char *p);
 
 // ASN1_STRING_get_default_mask returns |B_ASN1_UTF8STRING|.
 OPENSSL_EXPORT unsigned long ASN1_STRING_get_default_mask(void);
 
 // ASN1_STRING_TABLE_cleanup does nothing.
 OPENSSL_EXPORT void ASN1_STRING_TABLE_cleanup(void);
 
 // M_ASN1_* are legacy aliases for various |ASN1_STRING| functions. Use the
 // functions themselves.
 #define M_ASN1_STRING_length(x) ASN1_STRING_length(x)
 #define M_ASN1_STRING_type(x) ASN1_STRING_type(x)
 #define M_ASN1_STRING_data(x) ASN1_STRING_data(x)
 #define M_ASN1_BIT_STRING_new() ASN1_BIT_STRING_new()
 #define M_ASN1_BIT_STRING_free(a) ASN1_BIT_STRING_free(a)
 #define M_ASN1_BIT_STRING_dup(a) ASN1_STRING_dup(a)
 #define M_ASN1_BIT_STRING_cmp(a, b) ASN1_STRING_cmp(a, b)
 #define M_ASN1_BIT_STRING_set(a, b, c) ASN1_BIT_STRING_set(a, b, c)
 #define M_ASN1_INTEGER_new() ASN1_INTEGER_new()
 #define M_ASN1_INTEGER_free(a) ASN1_INTEGER_free(a)
 #define M_ASN1_INTEGER_dup(a) ASN1_INTEGER_dup(a)
 #define M_ASN1_INTEGER_cmp(a, b) ASN1_INTEGER_cmp(a, b)
 #define M_ASN1_ENUMERATED_new() ASN1_ENUMERATED_new()
 #define M_ASN1_ENUMERATED_free(a) ASN1_ENUMERATED_free(a)
 #define M_ASN1_ENUMERATED_dup(a) ASN1_STRING_dup(a)
 #define M_ASN1_ENUMERATED_cmp(a, b) ASN1_STRING_cmp(a, b)
 #define M_ASN1_OCTET_STRING_new() ASN1_OCTET_STRING_new()
 #define M_ASN1_OCTET_STRING_free(a) ASN1_OCTET_STRING_free()
 #define M_ASN1_OCTET_STRING_dup(a) ASN1_OCTET_STRING_dup(a)
 #define M_ASN1_OCTET_STRING_cmp(a, b) ASN1_OCTET_STRING_cmp(a, b)
 #define M_ASN1_OCTET_STRING_set(a, b, c) ASN1_OCTET_STRING_set(a, b, c)
 #define M_ASN1_OCTET_STRING_print(a, b) ASN1_STRING_print(a, b)
 #define M_ASN1_PRINTABLESTRING_new() ASN1_PRINTABLESTRING_new()
 #define M_ASN1_PRINTABLESTRING_free(a) ASN1_PRINTABLESTRING_free(a)
 #define M_ASN1_IA5STRING_new() ASN1_IA5STRING_new()
 #define M_ASN1_IA5STRING_free(a) ASN1_IA5STRING_free(a)
 #define M_ASN1_IA5STRING_dup(a) ASN1_STRING_dup(a)
 #define M_ASN1_UTCTIME_new() ASN1_UTCTIME_new()
 #define M_ASN1_UTCTIME_free(a) ASN1_UTCTIME_free(a)
 #define M_ASN1_UTCTIME_dup(a) ASN1_STRING_dup(a)
 #define M_ASN1_T61STRING_new() ASN1_T61STRING_new()
 #define M_ASN1_T61STRING_free(a) ASN1_T61STRING_free(a)
 #define M_ASN1_GENERALIZEDTIME_new() ASN1_GENERALIZEDTIME_new()
 #define M_ASN1_GENERALIZEDTIME_free(a) ASN1_GENERALIZEDTIME_free(a)
 #define M_ASN1_GENERALIZEDTIME_dup(a) ASN1_STRING_dup(a)
 #define M_ASN1_GENERALSTRING_new() ASN1_GENERALSTRING_new()
 #define M_ASN1_GENERALSTRING_free(a) ASN1_GENERALSTRING_free(a)
 #define M_ASN1_UNIVERSALSTRING_new() ASN1_UNIVERSALSTRING_new()
 #define M_ASN1_UNIVERSALSTRING_free(a) ASN1_UNIVERSALSTRING_free(a)
 #define M_ASN1_BMPSTRING_new() ASN1_BMPSTRING_new()
 #define M_ASN1_BMPSTRING_free(a) ASN1_BMPSTRING_free(a)
 #define M_ASN1_VISIBLESTRING_new() ASN1_VISIBLESTRING_new()
 #define M_ASN1_VISIBLESTRING_free(a) ASN1_VISIBLESTRING_free(a)
 #define M_ASN1_UTF8STRING_new() ASN1_UTF8STRING_new()
 #define M_ASN1_UTF8STRING_free(a) ASN1_UTF8STRING_free(a)
 
 // ASN1_INTEGER_set sets |a| to an INTEGER with value |v|. It returns one on
 // success and zero on error.
 //
 // Use |ASN1_INTEGER_set_uint64| and |ASN1_INTEGER_set_int64| instead.
 OPENSSL_EXPORT int ASN1_INTEGER_set(ASN1_INTEGER *a, long v);
 
 // ASN1_ENUMERATED_set sets |a| to an ENUMERATED with value |v|. It returns one
 // on success and zero on error.
 //
 // Use |ASN1_ENUMERATED_set_uint64| and |ASN1_ENUMERATED_set_int64| instead.
 OPENSSL_EXPORT int ASN1_ENUMERATED_set(ASN1_ENUMERATED *a, long v);
 
 // ASN1_INTEGER_get returns the value of |a| as a |long|, or -1 if |a| is out of
 // range or the wrong type.
 //
 // WARNING: This function's return value cannot distinguish errors from -1.
 // Use |ASN1_INTEGER_get_uint64| and |ASN1_INTEGER_get_int64| instead.
 OPENSSL_EXPORT long ASN1_INTEGER_get(const ASN1_INTEGER *a);
 
 // ASN1_ENUMERATED_get returns the value of |a| as a |long|, or -1 if |a| is out
 // of range or the wrong type.
 //
 // WARNING: This function's return value cannot distinguish errors from -1.
 // Use |ASN1_ENUMERATED_get_uint64| and |ASN1_ENUMERATED_get_int64| instead.
 OPENSSL_EXPORT long ASN1_ENUMERATED_get(const ASN1_ENUMERATED *a);
 
 
 #if defined(__cplusplus)
 }  // extern C
 
 extern "C++" {
 
 BSSL_NAMESPACE_BEGIN
 
 BORINGSSL_MAKE_DELETER(ASN1_OBJECT, ASN1_OBJECT_free)
 BORINGSSL_MAKE_DELETER(ASN1_STRING, ASN1_STRING_free)
 BORINGSSL_MAKE_DELETER(ASN1_TYPE, ASN1_TYPE_free)
 
 BSSL_NAMESPACE_END
 
 }  // extern C++
 
 #endif
 
 #define ASN1_R_ASN1_LENGTH_MISMATCH 100
 #define ASN1_R_AUX_ERROR 101
 #define ASN1_R_BAD_GET_ASN1_OBJECT_CALL 102
 #define ASN1_R_BAD_OBJECT_HEADER 103
 #define ASN1_R_BMPSTRING_IS_WRONG_LENGTH 104
 #define ASN1_R_BN_LIB 105
 #define ASN1_R_BOOLEAN_IS_WRONG_LENGTH 106
 #define ASN1_R_BUFFER_TOO_SMALL 107
 #define ASN1_R_CONTEXT_NOT_INITIALISED 108
 #define ASN1_R_DECODE_ERROR 109
 #define ASN1_R_DEPTH_EXCEEDED 110
 #define ASN1_R_DIGEST_AND_KEY_TYPE_NOT_SUPPORTED 111
 #define ASN1_R_ENCODE_ERROR 112
 #define ASN1_R_ERROR_GETTING_TIME 113
 #define ASN1_R_EXPECTING_AN_ASN1_SEQUENCE 114
 #define ASN1_R_EXPECTING_AN_INTEGER 115
 #define ASN1_R_EXPECTING_AN_OBJECT 116
 #define ASN1_R_EXPECTING_A_BOOLEAN 117
 #define ASN1_R_EXPECTING_A_TIME 118
 #define ASN1_R_EXPLICIT_LENGTH_MISMATCH 119
 #define ASN1_R_EXPLICIT_TAG_NOT_CONSTRUCTED 120
 #define ASN1_R_FIELD_MISSING 121
 #define ASN1_R_FIRST_NUM_TOO_LARGE 122
 #define ASN1_R_HEADER_TOO_LONG 123
 #define ASN1_R_ILLEGAL_BITSTRING_FORMAT 124
 #define ASN1_R_ILLEGAL_BOOLEAN 125
 #define ASN1_R_ILLEGAL_CHARACTERS 126
 #define ASN1_R_ILLEGAL_FORMAT 127
 #define ASN1_R_ILLEGAL_HEX 128
 #define ASN1_R_ILLEGAL_IMPLICIT_TAG 129
 #define ASN1_R_ILLEGAL_INTEGER 130
 #define ASN1_R_ILLEGAL_NESTED_TAGGING 131
 #define ASN1_R_ILLEGAL_NULL 132
 #define ASN1_R_ILLEGAL_NULL_VALUE 133
 #define ASN1_R_ILLEGAL_OBJECT 134
 #define ASN1_R_ILLEGAL_OPTIONAL_ANY 135
 #define ASN1_R_ILLEGAL_OPTIONS_ON_ITEM_TEMPLATE 136
 #define ASN1_R_ILLEGAL_TAGGED_ANY 137
 #define ASN1_R_ILLEGAL_TIME_VALUE 138
 #define ASN1_R_INTEGER_NOT_ASCII_FORMAT 139
 #define ASN1_R_INTEGER_TOO_LARGE_FOR_LONG 140
 #define ASN1_R_INVALID_BIT_STRING_BITS_LEFT 141
 #define ASN1_R_INVALID_BMPSTRING 142
 #define ASN1_R_INVALID_DIGIT 143
 #define ASN1_R_INVALID_MODIFIER 144
 #define ASN1_R_INVALID_NUMBER 145
 #define ASN1_R_INVALID_OBJECT_ENCODING 146
 #define ASN1_R_INVALID_SEPARATOR 147
 #define ASN1_R_INVALID_TIME_FORMAT 148
 #define ASN1_R_INVALID_UNIVERSALSTRING 149
 #define ASN1_R_INVALID_UTF8STRING 150
 #define ASN1_R_LIST_ERROR 151
 #define ASN1_R_MISSING_ASN1_EOS 152
 #define ASN1_R_MISSING_EOC 153
 #define ASN1_R_MISSING_SECOND_NUMBER 154
 #define ASN1_R_MISSING_VALUE 155
 #define ASN1_R_MSTRING_NOT_UNIVERSAL 156
 #define ASN1_R_MSTRING_WRONG_TAG 157
 #define ASN1_R_NESTED_ASN1_ERROR 158
 #define ASN1_R_NESTED_ASN1_STRING 159
 #define ASN1_R_NON_HEX_CHARACTERS 160
 #define ASN1_R_NOT_ASCII_FORMAT 161
 #define ASN1_R_NOT_ENOUGH_DATA 162
 #define ASN1_R_NO_MATCHING_CHOICE_TYPE 163
 #define ASN1_R_NULL_IS_WRONG_LENGTH 164
 #define ASN1_R_OBJECT_NOT_ASCII_FORMAT 165
 #define ASN1_R_ODD_NUMBER_OF_CHARS 166
 #define ASN1_R_SECOND_NUMBER_TOO_LARGE 167
 #define ASN1_R_SEQUENCE_LENGTH_MISMATCH 168
 #define ASN1_R_SEQUENCE_NOT_CONSTRUCTED 169
 #define ASN1_R_SEQUENCE_OR_SET_NEEDS_CONFIG 170
 #define ASN1_R_SHORT_LINE 171
 #define ASN1_R_STREAMING_NOT_SUPPORTED 172
 #define ASN1_R_STRING_TOO_LONG 173
 #define ASN1_R_STRING_TOO_SHORT 174
 #define ASN1_R_TAG_VALUE_TOO_HIGH 175
 #define ASN1_R_TIME_NOT_ASCII_FORMAT 176
 #define ASN1_R_TOO_LONG 177
 #define ASN1_R_TYPE_NOT_CONSTRUCTED 178
 #define ASN1_R_TYPE_NOT_PRIMITIVE 179
 #define ASN1_R_UNEXPECTED_EOC 180
 #define ASN1_R_UNIVERSALSTRING_IS_WRONG_LENGTH 181
 #define ASN1_R_UNKNOWN_FORMAT 182
 #define ASN1_R_UNKNOWN_MESSAGE_DIGEST_ALGORITHM 183
 #define ASN1_R_UNKNOWN_SIGNATURE_ALGORITHM 184
 #define ASN1_R_UNKNOWN_TAG 185
 #define ASN1_R_UNSUPPORTED_ANY_DEFINED_BY_TYPE 186
 #define ASN1_R_UNSUPPORTED_PUBLIC_KEY_TYPE 187
 #define ASN1_R_UNSUPPORTED_TYPE 188
 #define ASN1_R_WRONG_PUBLIC_KEY_TYPE 189
 #define ASN1_R_WRONG_TAG 190
 #define ASN1_R_WRONG_TYPE 191
 #define ASN1_R_NESTED_TOO_DEEP 192
 #define ASN1_R_BAD_TEMPLATE 193
 #define ASN1_R_INVALID_BIT_STRING_PADDING 194
 #define ASN1_R_WRONG_INTEGER_TYPE 195
 #define ASN1_R_INVALID_INTEGER 196
 
 #endif  // OPENSSL_HEADER_ASN1_H