crypto/libressl/crypto/hmac/hmac.c

   1 /* $OpenBSD: hmac.c,v 1.21 2014/07/11 08:44:48 jsing Exp $ */
   2 /* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
   3  * All rights reserved.
   4  *
   5  * This package is an SSL implementation written
   6  * by Eric Young (eay@cryptsoft.com).
   7  * The implementation was written so as to conform with Netscapes SSL.
   8  *
   9  * This library is free for commercial and non-commercial use as long as
  10  * the following conditions are aheared to.  The following conditions
  11  * apply to all code found in this distribution, be it the RC4, RSA,
  12  * lhash, DES, etc., code; not just the SSL code.  The SSL documentation
  13  * included with this distribution is covered by the same copyright terms
  14  * except that the holder is Tim Hudson (tjh@cryptsoft.com).
  15  *
  16  * Copyright remains Eric Young's, and as such any Copyright notices in
  17  * the code are not to be removed.
  18  * If this package is used in a product, Eric Young should be given attribution
  19  * as the author of the parts of the library used.
  20  * This can be in the form of a textual message at program startup or
  21  * in documentation (online or textual) provided with the package.
  22  *
  23  * Redistribution and use in source and binary forms, with or without
  24  * modification, are permitted provided that the following conditions
  25  * are met:
  26  * 1. Redistributions of source code must retain the copyright
  27  *    notice, this list of conditions and the following disclaimer.
  28  * 2. Redistributions in binary form must reproduce the above copyright
  29  *    notice, this list of conditions and the following disclaimer in the
  30  *    documentation and/or other materials provided with the distribution.
  31  * 3. All advertising materials mentioning features or use of this software
  32  *    must display the following acknowledgement:
  33  *    "This product includes cryptographic software written by
  34  *     Eric Young (eay@cryptsoft.com)"
  35  *    The word 'cryptographic' can be left out if the rouines from the library
  36  *    being used are not cryptographic related :-).
  37  * 4. If you include any Windows specific code (or a derivative thereof) from
  38  *    the apps directory (application code) you must include an acknowledgement:
  39  *    "This product includes software written by Tim Hudson (tjh@cryptsoft.com)"
  40  *
  41  * THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND
  42  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  43  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  44  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
  45  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  46  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  47  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  48  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  49  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  50  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  51  * SUCH DAMAGE.
  52  *
  53  * The licence and distribution terms for any publically available version or
  54  * derivative of this code cannot be changed.  i.e. this code cannot simply be
  55  * copied and put under another distribution licence
  56  * [including the GNU Public Licence.]
  57  */
  58
  59 #include <stdio.h>
  60 #include <stdlib.h>
  61 #include <string.h>
  62
  63 #include <openssl/err.h>
  64 #include <openssl/hmac.h>
  65
  66 int
  67 HMAC_Init_ex(HMAC_CTX *ctx, const void *key, int len, const EVP_MD *md,
  68     ENGINE *impl)
  69 {
  70         int i, j, reset = 0;
  71         unsigned char pad[HMAC_MAX_MD_CBLOCK];
  72
  73         if (md != NULL) {
  74                 reset = 1;
  75                 ctx->md = md;
  76         } else
  77                 md = ctx->md;
  78
  79         if (key != NULL) {
  80                 reset = 1;
  81                 j = EVP_MD_block_size(md);
  82                 if ((size_t)j > sizeof(ctx->key)) {
  83                         EVPerr(EVP_F_HMAC_INIT_EX, EVP_R_BAD_BLOCK_LENGTH);
  84                         goto err;
  85                 }
  86                 if (j < len) {
  87                         if (!EVP_DigestInit_ex(&ctx->md_ctx, md, impl))
  88                                 goto err;
  89                         if (!EVP_DigestUpdate(&ctx->md_ctx, key, len))
  90                                 goto err;
  91                         if (!EVP_DigestFinal_ex(&(ctx->md_ctx), ctx->key,
  92                             &ctx->key_length))
  93                                 goto err;
  94                 } else {
  95                         if ((size_t)len > sizeof(ctx->key)) {
  96                                 EVPerr(EVP_F_HMAC_INIT_EX,
  97                                     EVP_R_BAD_KEY_LENGTH);
  98                                 goto err;
  99                         }
 100                         memcpy(ctx->key, key, len);
 101                         ctx->key_length = len;
 102                 }
 103                 if (ctx->key_length != HMAC_MAX_MD_CBLOCK)
 104                         memset(&ctx->key[ctx->key_length], 0,
 105                             HMAC_MAX_MD_CBLOCK - ctx->key_length);
 106         }
 107
 108         if (reset) {
 109                 for (i = 0; i < HMAC_MAX_MD_CBLOCK; i++)
 110                         pad[i] = 0x36 ^ ctx->key[i];
 111                 if (!EVP_DigestInit_ex(&ctx->i_ctx, md, impl))
 112                         goto err;
 113                 if (!EVP_DigestUpdate(&ctx->i_ctx, pad, EVP_MD_block_size(md)))
 114                         goto err;
 115
 116                 for (i = 0; i < HMAC_MAX_MD_CBLOCK; i++)
 117                         pad[i] = 0x5c ^ ctx->key[i];
 118                 if (!EVP_DigestInit_ex(&ctx->o_ctx, md, impl))
 119                         goto err;
 120                 if (!EVP_DigestUpdate(&ctx->o_ctx, pad, EVP_MD_block_size(md)))
 121                         goto err;
 122         }
 123         if (!EVP_MD_CTX_copy_ex(&ctx->md_ctx, &ctx->i_ctx))
 124                 goto err;
 125         return 1;
 126 err:
 127         return 0;
 128 }
 129
 130 int
 131 HMAC_Init(HMAC_CTX *ctx, const void *key, int len, const EVP_MD *md)
 132 {
 133         if (key && md)
 134                 HMAC_CTX_init(ctx);
 135         return HMAC_Init_ex(ctx, key, len, md, NULL);
 136 }
 137
 138 int
 139 HMAC_Update(HMAC_CTX *ctx, const unsigned char *data, size_t len)
 140 {
 141         return EVP_DigestUpdate(&ctx->md_ctx, data, len);
 142 }
 143
 144 int
 145 HMAC_Final(HMAC_CTX *ctx, unsigned char *md, unsigned int *len)
 146 {
 147         unsigned int i;
 148         unsigned char buf[EVP_MAX_MD_SIZE];
 149
 150         if (!EVP_DigestFinal_ex(&ctx->md_ctx, buf, &i))
 151                 goto err;
 152         if (!EVP_MD_CTX_copy_ex(&ctx->md_ctx, &ctx->o_ctx))
 153                 goto err;
 154         if (!EVP_DigestUpdate(&ctx->md_ctx, buf, i))
 155                 goto err;
 156         if (!EVP_DigestFinal_ex(&ctx->md_ctx, md, len))
 157                 goto err;
 158         return 1;
 159 err:
 160         return 0;
 161 }
 162
 163 void
 164 HMAC_CTX_init(HMAC_CTX *ctx)
 165 {
 166         EVP_MD_CTX_init(&ctx->i_ctx);
 167         EVP_MD_CTX_init(&ctx->o_ctx);
 168         EVP_MD_CTX_init(&ctx->md_ctx);
 169 }
 170
 171 int
 172 HMAC_CTX_copy(HMAC_CTX *dctx, HMAC_CTX *sctx)
 173 {
 174         if (!EVP_MD_CTX_copy(&dctx->i_ctx, &sctx->i_ctx))
 175                 goto err;
 176         if (!EVP_MD_CTX_copy(&dctx->o_ctx, &sctx->o_ctx))
 177                 goto err;
 178         if (!EVP_MD_CTX_copy(&dctx->md_ctx, &sctx->md_ctx))
 179                 goto err;
 180         memcpy(dctx->key, sctx->key, HMAC_MAX_MD_CBLOCK);
 181         dctx->key_length = sctx->key_length;
 182         dctx->md = sctx->md;
 183         return 1;
 184 err:
 185         return 0;
 186 }
 187
 188 void
 189 HMAC_CTX_cleanup(HMAC_CTX *ctx)
 190 {
 191         EVP_MD_CTX_cleanup(&ctx->i_ctx);
 192         EVP_MD_CTX_cleanup(&ctx->o_ctx);
 193         EVP_MD_CTX_cleanup(&ctx->md_ctx);
 194         memset(ctx, 0, sizeof *ctx);
 195 }
 196
 197 unsigned char *
 198 HMAC(const EVP_MD *evp_md, const void *key, int key_len, const unsigned char *d,
 199     size_t n, unsigned char *md, unsigned int *md_len)
 200 {
 201         HMAC_CTX c;
 202         static unsigned char m[EVP_MAX_MD_SIZE];
 203
 204         if (md == NULL)
 205                 md = m;
 206         HMAC_CTX_init(&c);
 207         if (!HMAC_Init(&c, key, key_len, evp_md))
 208                 goto err;
 209         if (!HMAC_Update(&c, d, n))
 210                 goto err;
 211         if (!HMAC_Final(&c, md, md_len))
 212                 goto err;
 213         HMAC_CTX_cleanup(&c);
 214         return md;
 215 err:
 216         return NULL;
 217 }
 218
 219 void
 220 HMAC_CTX_set_flags(HMAC_CTX *ctx, unsigned long flags)
 221 {
 222         EVP_MD_CTX_set_flags(&ctx->i_ctx, flags);
 223         EVP_MD_CTX_set_flags(&ctx->o_ctx, flags);
 224         EVP_MD_CTX_set_flags(&ctx->md_ctx, flags);
 225 }