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      1 /* Copyright (C) 1995-1998 Eric Young (eay (at) cryptsoft.com)
      2  * All rights reserved.
      3  *
      4  * This package is an SSL implementation written
      5  * by Eric Young (eay (at) cryptsoft.com).
      6  * The implementation was written so as to conform with Netscapes SSL.
      7  *
      8  * This library is free for commercial and non-commercial use as long as
      9  * the following conditions are aheared to.  The following conditions
     10  * apply to all code found in this distribution, be it the RC4, RSA,
     11  * lhash, DES, etc., code; not just the SSL code.  The SSL documentation
     12  * included with this distribution is covered by the same copyright terms
     13  * except that the holder is Tim Hudson (tjh (at) cryptsoft.com).
     14  *
     15  * Copyright remains Eric Young's, and as such any Copyright notices in
     16  * the code are not to be removed.
     17  * If this package is used in a product, Eric Young should be given attribution
     18  * as the author of the parts of the library used.
     19  * This can be in the form of a textual message at program startup or
     20  * in documentation (online or textual) provided with the package.
     21  *
     22  * Redistribution and use in source and binary forms, with or without
     23  * modification, are permitted provided that the following conditions
     24  * are met:
     25  * 1. Redistributions of source code must retain the copyright
     26  *    notice, this list of conditions and the following disclaimer.
     27  * 2. Redistributions in binary form must reproduce the above copyright
     28  *    notice, this list of conditions and the following disclaimer in the
     29  *    documentation and/or other materials provided with the distribution.
     30  * 3. All advertising materials mentioning features or use of this software
     31  *    must display the following acknowledgement:
     32  *    "This product includes cryptographic software written by
     33  *     Eric Young (eay (at) cryptsoft.com)"
     34  *    The word 'cryptographic' can be left out if the rouines from the library
     35  *    being used are not cryptographic related :-).
     36  * 4. If you include any Windows specific code (or a derivative thereof) from
     37  *    the apps directory (application code) you must include an acknowledgement:
     38  *    "This product includes software written by Tim Hudson (tjh (at) cryptsoft.com)"
     39  *
     40  * THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND
     41  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     42  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
     43  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
     44  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
     45  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
     46  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     47  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
     48  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     49  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     50  * SUCH DAMAGE.
     51  *
     52  * The licence and distribution terms for any publically available version or
     53  * derivative of this code cannot be changed.  i.e. this code cannot simply be
     54  * copied and put under another distribution licence
     55  * [including the GNU Public Licence.] */
     56 
     57 #ifndef OPENSSL_HEADER_DIGEST_H
     58 #define OPENSSL_HEADER_DIGEST_H
     59 
     60 #include <openssl/base.h>
     61 
     62 #if defined(__cplusplus)
     63 extern "C" {
     64 #endif
     65 
     66 
     67 // Digest functions.
     68 //
     69 // An EVP_MD abstracts the details of a specific hash function allowing code to
     70 // deal with the concept of a "hash function" without needing to know exactly
     71 // which hash function it is.
     72 
     73 
     74 // Hash algorithms.
     75 //
     76 // The following functions return |EVP_MD| objects that implement the named hash
     77 // function.
     78 
     79 OPENSSL_EXPORT const EVP_MD *EVP_md4(void);
     80 OPENSSL_EXPORT const EVP_MD *EVP_md5(void);
     81 OPENSSL_EXPORT const EVP_MD *EVP_sha1(void);
     82 OPENSSL_EXPORT const EVP_MD *EVP_sha224(void);
     83 OPENSSL_EXPORT const EVP_MD *EVP_sha256(void);
     84 OPENSSL_EXPORT const EVP_MD *EVP_sha384(void);
     85 OPENSSL_EXPORT const EVP_MD *EVP_sha512(void);
     86 
     87 // EVP_md5_sha1 is a TLS-specific |EVP_MD| which computes the concatenation of
     88 // MD5 and SHA-1, as used in TLS 1.1 and below.
     89 OPENSSL_EXPORT const EVP_MD *EVP_md5_sha1(void);
     90 
     91 // EVP_get_digestbynid returns an |EVP_MD| for the given NID, or NULL if no
     92 // such digest is known.
     93 OPENSSL_EXPORT const EVP_MD *EVP_get_digestbynid(int nid);
     94 
     95 // EVP_get_digestbyobj returns an |EVP_MD| for the given |ASN1_OBJECT|, or NULL
     96 // if no such digest is known.
     97 OPENSSL_EXPORT const EVP_MD *EVP_get_digestbyobj(const ASN1_OBJECT *obj);
     98 
     99 
    100 // Digest contexts.
    101 //
    102 // An EVP_MD_CTX represents the state of a specific digest operation in
    103 // progress.
    104 
    105 // EVP_MD_CTX_init initialises an, already allocated, |EVP_MD_CTX|. This is the
    106 // same as setting the structure to zero.
    107 OPENSSL_EXPORT void EVP_MD_CTX_init(EVP_MD_CTX *ctx);
    108 
    109 // EVP_MD_CTX_new allocates and initialises a fresh |EVP_MD_CTX| and returns
    110 // it, or NULL on allocation failure. The caller must use |EVP_MD_CTX_free| to
    111 // release the resulting object.
    112 OPENSSL_EXPORT EVP_MD_CTX *EVP_MD_CTX_new(void);
    113 
    114 // EVP_MD_CTX_cleanup frees any resources owned by |ctx| and resets it to a
    115 // freshly initialised state. It does not free |ctx| itself. It returns one.
    116 OPENSSL_EXPORT int EVP_MD_CTX_cleanup(EVP_MD_CTX *ctx);
    117 
    118 // EVP_MD_CTX_free calls |EVP_MD_CTX_cleanup| and then frees |ctx| itself.
    119 OPENSSL_EXPORT void EVP_MD_CTX_free(EVP_MD_CTX *ctx);
    120 
    121 // EVP_MD_CTX_copy_ex sets |out|, which must already be initialised, to be a
    122 // copy of |in|. It returns one on success and zero on error.
    123 OPENSSL_EXPORT int EVP_MD_CTX_copy_ex(EVP_MD_CTX *out, const EVP_MD_CTX *in);
    124 
    125 // EVP_MD_CTX_reset calls |EVP_MD_CTX_cleanup| followed by |EVP_MD_CTX_init|.
    126 OPENSSL_EXPORT void EVP_MD_CTX_reset(EVP_MD_CTX *ctx);
    127 
    128 
    129 // Digest operations.
    130 
    131 // EVP_DigestInit_ex configures |ctx|, which must already have been
    132 // initialised, for a fresh hashing operation using |type|. It returns one on
    133 // success and zero otherwise.
    134 OPENSSL_EXPORT int EVP_DigestInit_ex(EVP_MD_CTX *ctx, const EVP_MD *type,
    135                                      ENGINE *engine);
    136 
    137 // EVP_DigestInit acts like |EVP_DigestInit_ex| except that |ctx| is
    138 // initialised before use.
    139 OPENSSL_EXPORT int EVP_DigestInit(EVP_MD_CTX *ctx, const EVP_MD *type);
    140 
    141 // EVP_DigestUpdate hashes |len| bytes from |data| into the hashing operation
    142 // in |ctx|. It returns one.
    143 OPENSSL_EXPORT int EVP_DigestUpdate(EVP_MD_CTX *ctx, const void *data,
    144                                     size_t len);
    145 
    146 // EVP_MAX_MD_SIZE is the largest digest size supported, in bytes.
    147 // Functions that output a digest generally require the buffer have
    148 // at least this much space.
    149 #define EVP_MAX_MD_SIZE 64  // SHA-512 is the longest so far.
    150 
    151 // EVP_MAX_MD_BLOCK_SIZE is the largest digest block size supported, in
    152 // bytes.
    153 #define EVP_MAX_MD_BLOCK_SIZE 128  // SHA-512 is the longest so far.
    154 
    155 // EVP_DigestFinal_ex finishes the digest in |ctx| and writes the output to
    156 // |md_out|. |EVP_MD_CTX_size| bytes are written, which is at most
    157 // |EVP_MAX_MD_SIZE|. If |out_size| is not NULL then |*out_size| is set to the
    158 // number of bytes written. It returns one. After this call, the hash cannot be
    159 // updated or finished again until |EVP_DigestInit_ex| is called to start
    160 // another hashing operation.
    161 OPENSSL_EXPORT int EVP_DigestFinal_ex(EVP_MD_CTX *ctx, uint8_t *md_out,
    162                                       unsigned int *out_size);
    163 
    164 // EVP_DigestFinal acts like |EVP_DigestFinal_ex| except that
    165 // |EVP_MD_CTX_cleanup| is called on |ctx| before returning.
    166 OPENSSL_EXPORT int EVP_DigestFinal(EVP_MD_CTX *ctx, uint8_t *md_out,
    167                                    unsigned int *out_size);
    168 
    169 // EVP_Digest performs a complete hashing operation in one call. It hashes |len|
    170 // bytes from |data| and writes the digest to |md_out|. |EVP_MD_CTX_size| bytes
    171 // are written, which is at most |EVP_MAX_MD_SIZE|. If |out_size| is not NULL
    172 // then |*out_size| is set to the number of bytes written. It returns one on
    173 // success and zero otherwise.
    174 OPENSSL_EXPORT int EVP_Digest(const void *data, size_t len, uint8_t *md_out,
    175                               unsigned int *md_out_size, const EVP_MD *type,
    176                               ENGINE *impl);
    177 
    178 
    179 // Digest function accessors.
    180 //
    181 // These functions allow code to learn details about an abstract hash
    182 // function.
    183 
    184 // EVP_MD_type returns a NID identifying |md|. (For example, |NID_sha256|.)
    185 OPENSSL_EXPORT int EVP_MD_type(const EVP_MD *md);
    186 
    187 // EVP_MD_flags returns the flags for |md|, which is a set of |EVP_MD_FLAG_*|
    188 // values, ORed together.
    189 OPENSSL_EXPORT uint32_t EVP_MD_flags(const EVP_MD *md);
    190 
    191 // EVP_MD_size returns the digest size of |md|, in bytes.
    192 OPENSSL_EXPORT size_t EVP_MD_size(const EVP_MD *md);
    193 
    194 // EVP_MD_block_size returns the native block-size of |md|, in bytes.
    195 OPENSSL_EXPORT size_t EVP_MD_block_size(const EVP_MD *md);
    196 
    197 // EVP_MD_FLAG_PKEY_DIGEST indicates the the digest function is used with a
    198 // specific public key in order to verify signatures. (For example,
    199 // EVP_dss1.)
    200 #define EVP_MD_FLAG_PKEY_DIGEST 1
    201 
    202 // EVP_MD_FLAG_DIGALGID_ABSENT indicates that the parameter type in an X.509
    203 // DigestAlgorithmIdentifier representing this digest function should be
    204 // undefined rather than NULL.
    205 #define EVP_MD_FLAG_DIGALGID_ABSENT 2
    206 
    207 
    208 // Digest operation accessors.
    209 
    210 // EVP_MD_CTX_md returns the underlying digest function, or NULL if one has not
    211 // been set.
    212 OPENSSL_EXPORT const EVP_MD *EVP_MD_CTX_md(const EVP_MD_CTX *ctx);
    213 
    214 // EVP_MD_CTX_size returns the digest size of |ctx|, in bytes. It
    215 // will crash if a digest hasn't been set on |ctx|.
    216 OPENSSL_EXPORT size_t EVP_MD_CTX_size(const EVP_MD_CTX *ctx);
    217 
    218 // EVP_MD_CTX_block_size returns the block size of the digest function used by
    219 // |ctx|, in bytes. It will crash if a digest hasn't been set on |ctx|.
    220 OPENSSL_EXPORT size_t EVP_MD_CTX_block_size(const EVP_MD_CTX *ctx);
    221 
    222 // EVP_MD_CTX_type returns a NID describing the digest function used by |ctx|.
    223 // (For example, |NID_sha256|.) It will crash if a digest hasn't been set on
    224 // |ctx|.
    225 OPENSSL_EXPORT int EVP_MD_CTX_type(const EVP_MD_CTX *ctx);
    226 
    227 
    228 // ASN.1 functions.
    229 //
    230 // These functions allow code to parse and serialize AlgorithmIdentifiers for
    231 // hash functions.
    232 
    233 // EVP_parse_digest_algorithm parses an AlgorithmIdentifier structure containing
    234 // a hash function OID (for example, 2.16.840.1.101.3.4.2.1 is SHA-256) and
    235 // advances |cbs|. The parameters field may either be omitted or a NULL. It
    236 // returns the digest function or NULL on error.
    237 OPENSSL_EXPORT const EVP_MD *EVP_parse_digest_algorithm(CBS *cbs);
    238 
    239 // EVP_marshal_digest_algorithm marshals |md| as an AlgorithmIdentifier
    240 // structure and appends the result to |cbb|. It returns one on success and zero
    241 // on error.
    242 OPENSSL_EXPORT int EVP_marshal_digest_algorithm(CBB *cbb, const EVP_MD *md);
    243 
    244 
    245 // Deprecated functions.
    246 
    247 // EVP_MD_CTX_copy sets |out|, which must /not/ be initialised, to be a copy of
    248 // |in|. It returns one on success and zero on error.
    249 OPENSSL_EXPORT int EVP_MD_CTX_copy(EVP_MD_CTX *out, const EVP_MD_CTX *in);
    250 
    251 // EVP_add_digest does nothing and returns one. It exists only for
    252 // compatibility with OpenSSL.
    253 OPENSSL_EXPORT int EVP_add_digest(const EVP_MD *digest);
    254 
    255 // EVP_get_digestbyname returns an |EVP_MD| given a human readable name in
    256 // |name|, or NULL if the name is unknown.
    257 OPENSSL_EXPORT const EVP_MD *EVP_get_digestbyname(const char *);
    258 
    259 // EVP_dss1 returns the value of EVP_sha1(). This was provided by OpenSSL to
    260 // specifiy the original DSA signatures, which were fixed to use SHA-1. Note,
    261 // however, that attempting to sign or verify DSA signatures with the EVP
    262 // interface will always fail.
    263 OPENSSL_EXPORT const EVP_MD *EVP_dss1(void);
    264 
    265 // EVP_MD_CTX_create calls |EVP_MD_CTX_new|.
    266 OPENSSL_EXPORT EVP_MD_CTX *EVP_MD_CTX_create(void);
    267 
    268 // EVP_MD_CTX_destroy calls |EVP_MD_CTX_free|.
    269 OPENSSL_EXPORT void EVP_MD_CTX_destroy(EVP_MD_CTX *ctx);
    270 
    271 
    272 struct evp_md_pctx_ops;
    273 
    274 struct env_md_ctx_st {
    275   // digest is the underlying digest function, or NULL if not set.
    276   const EVP_MD *digest;
    277   // md_data points to a block of memory that contains the hash-specific
    278   // context.
    279   void *md_data;
    280 
    281   // pctx is an opaque (at this layer) pointer to additional context that
    282   // EVP_PKEY functions may store in this object.
    283   EVP_PKEY_CTX *pctx;
    284 
    285   // pctx_ops, if not NULL, points to a vtable that contains functions to
    286   // manipulate |pctx|.
    287   const struct evp_md_pctx_ops *pctx_ops;
    288 } /* EVP_MD_CTX */;
    289 
    290 
    291 #if defined(__cplusplus)
    292 }  // extern C
    293 
    294 #if !defined(BORINGSSL_NO_CXX)
    295 extern "C++" {
    296 
    297 namespace bssl {
    298 
    299 BORINGSSL_MAKE_DELETER(EVP_MD_CTX, EVP_MD_CTX_free)
    300 
    301 using ScopedEVP_MD_CTX =
    302     internal::StackAllocated<EVP_MD_CTX, int, EVP_MD_CTX_init,
    303                              EVP_MD_CTX_cleanup>;
    304 
    305 }  // namespace bssl
    306 
    307 }  // extern C++
    308 #endif
    309 
    310 #endif
    311 
    312 #define DIGEST_R_INPUT_NOT_INITIALIZED 100
    313 #define DIGEST_R_DECODE_ERROR 101
    314 #define DIGEST_R_UNKNOWN_HASH 102
    315 
    316 #endif  // OPENSSL_HEADER_DIGEST_H
    317