crypto/hmac/hmac.c

   1 /* crypto/hmac/hmac.c */
   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 #include <stdio.h>
  59 #include <stdlib.h>
  60 #include <string.h>
  61 #include "cryptlib.h"
  62 #include <openssl/hmac.h>
  63
  64 #ifdef OPENSSL_FIPS
  65 # include <openssl/fips.h>
  66 #endif
  67
  68 int HMAC_Init_ex(HMAC_CTX *ctx, const void *key, int len,
  69                  const EVP_MD *md, ENGINE *impl)
  70 {
  71     int i, j, reset = 0;
  72     unsigned char pad[HMAC_MAX_MD_CBLOCK];
  73
  74 #ifdef OPENSSL_FIPS
  75     /* If FIPS mode switch to approved implementation if possible */
  76     if (FIPS_mode()) {
  77         const EVP_MD *fipsmd;
  78         if (md) {
  79             fipsmd = FIPS_get_digestbynid(EVP_MD_type(md));
  80             if (fipsmd)
  81                 md = fipsmd;
  82         }
  83     }
  84
  85     if (FIPS_mode()) {
  86         /* If we have an ENGINE need to allow non FIPS */
  87         if ((impl || ctx->i_ctx.engine)
  88             && !(ctx->i_ctx.flags & EVP_CIPH_FLAG_NON_FIPS_ALLOW)) {
  89             EVPerr(EVP_F_HMAC_INIT_EX, EVP_R_DISABLED_FOR_FIPS);
  90             return 0;
  91         }
  92         /*
  93          * Other algorithm blocking will be done in FIPS_cmac_init, via
  94          * FIPS_hmac_init_ex().
  95          */
  96         if (!impl && !ctx->i_ctx.engine)
  97             return FIPS_hmac_init_ex(ctx, key, len, md, NULL);
  98     }
  99 #endif
 100
 101     if (md != NULL) {
 102         reset = 1;
 103         ctx->md = md;
 104     } else
 105         md = ctx->md;
 106
 107     if (key != NULL) {
 108         reset = 1;
 109         j = EVP_MD_block_size(md);
 110         OPENSSL_assert(j <= (int)sizeof(ctx->key));
 111         if (j < len) {
 112             if (!EVP_DigestInit_ex(&ctx->md_ctx, md, impl))
 113                 goto err;
 114             if (!EVP_DigestUpdate(&ctx->md_ctx, key, len))
 115                 goto err;
 116             if (!EVP_DigestFinal_ex(&(ctx->md_ctx), ctx->key,
 117                                     &ctx->key_length))
 118                 goto err;
 119         } else {
 120             OPENSSL_assert(len >= 0 && len <= (int)sizeof(ctx->key));
 121             memcpy(ctx->key, key, len);
 122             ctx->key_length = len;
 123         }
 124         if (ctx->key_length != HMAC_MAX_MD_CBLOCK)
 125             memset(&ctx->key[ctx->key_length], 0,
 126                    HMAC_MAX_MD_CBLOCK - ctx->key_length);
 127     }
 128
 129     if (reset) {
 130         for (i = 0; i < HMAC_MAX_MD_CBLOCK; i++)
 131             pad[i] = 0x36 ^ ctx->key[i];
 132         if (!EVP_DigestInit_ex(&ctx->i_ctx, md, impl))
 133             goto err;
 134         if (!EVP_DigestUpdate(&ctx->i_ctx, pad, EVP_MD_block_size(md)))
 135             goto err;
 136
 137         for (i = 0; i < HMAC_MAX_MD_CBLOCK; i++)
 138             pad[i] = 0x5c ^ ctx->key[i];
 139         if (!EVP_DigestInit_ex(&ctx->o_ctx, md, impl))
 140             goto err;
 141         if (!EVP_DigestUpdate(&ctx->o_ctx, pad, EVP_MD_block_size(md)))
 142             goto err;
 143     }
 144     if (!EVP_MD_CTX_copy_ex(&ctx->md_ctx, &ctx->i_ctx))
 145         goto err;
 146     return 1;
 147  err:
 148     return 0;
 149 }
 150
 151 int HMAC_Init(HMAC_CTX *ctx, const void *key, int len, const EVP_MD *md)
 152 {
 153     if (key && md)
 154         HMAC_CTX_init(ctx);
 155     return HMAC_Init_ex(ctx, key, len, md, NULL);
 156 }
 157
 158 int HMAC_Update(HMAC_CTX *ctx, const unsigned char *data, size_t len)
 159 {
 160 #ifdef OPENSSL_FIPS
 161     if (FIPS_mode() && !ctx->i_ctx.engine)
 162         return FIPS_hmac_update(ctx, data, len);
 163 #endif
 164     return EVP_DigestUpdate(&ctx->md_ctx, data, len);
 165 }
 166
 167 int HMAC_Final(HMAC_CTX *ctx, unsigned char *md, unsigned int *len)
 168 {
 169     unsigned int i;
 170     unsigned char buf[EVP_MAX_MD_SIZE];
 171 #ifdef OPENSSL_FIPS
 172     if (FIPS_mode() && !ctx->i_ctx.engine)
 173         return FIPS_hmac_final(ctx, md, len);
 174 #endif
 175
 176     if (!EVP_DigestFinal_ex(&ctx->md_ctx, buf, &i))
 177         goto err;
 178     if (!EVP_MD_CTX_copy_ex(&ctx->md_ctx, &ctx->o_ctx))
 179         goto err;
 180     if (!EVP_DigestUpdate(&ctx->md_ctx, buf, i))
 181         goto err;
 182     if (!EVP_DigestFinal_ex(&ctx->md_ctx, md, len))
 183         goto err;
 184     return 1;
 185  err:
 186     return 0;
 187 }
 188
 189 void HMAC_CTX_init(HMAC_CTX *ctx)
 190 {
 191     EVP_MD_CTX_init(&ctx->i_ctx);
 192     EVP_MD_CTX_init(&ctx->o_ctx);
 193     EVP_MD_CTX_init(&ctx->md_ctx);
 194 }
 195
 196 int HMAC_CTX_copy(HMAC_CTX *dctx, HMAC_CTX *sctx)
 197 {
 198     if (!EVP_MD_CTX_copy(&dctx->i_ctx, &sctx->i_ctx))
 199         goto err;
 200     if (!EVP_MD_CTX_copy(&dctx->o_ctx, &sctx->o_ctx))
 201         goto err;
 202     if (!EVP_MD_CTX_copy(&dctx->md_ctx, &sctx->md_ctx))
 203         goto err;
 204     memcpy(dctx->key, sctx->key, HMAC_MAX_MD_CBLOCK);
 205     dctx->key_length = sctx->key_length;
 206     dctx->md = sctx->md;
 207     return 1;
 208  err:
 209     return 0;
 210 }
 211
 212 void HMAC_CTX_cleanup(HMAC_CTX *ctx)
 213 {
 214 #ifdef OPENSSL_FIPS
 215     if (FIPS_mode() && !ctx->i_ctx.engine) {
 216         FIPS_hmac_ctx_cleanup(ctx);
 217         return;
 218     }
 219 #endif
 220     EVP_MD_CTX_cleanup(&ctx->i_ctx);
 221     EVP_MD_CTX_cleanup(&ctx->o_ctx);
 222     EVP_MD_CTX_cleanup(&ctx->md_ctx);
 223     memset(ctx, 0, sizeof *ctx);
 224 }
 225
 226 unsigned char *HMAC(const EVP_MD *evp_md, const void *key, int key_len,
 227                     const unsigned char *d, size_t n, unsigned char *md,
 228                     unsigned int *md_len)
 229 {
 230     HMAC_CTX c;
 231     static unsigned char m[EVP_MAX_MD_SIZE];
 232
 233     if (md == NULL)
 234         md = m;
 235     HMAC_CTX_init(&c);
 236     if (!HMAC_Init(&c, key, key_len, evp_md))
 237         goto err;
 238     if (!HMAC_Update(&c, d, n))
 239         goto err;
 240     if (!HMAC_Final(&c, md, md_len))
 241         goto err;
 242     HMAC_CTX_cleanup(&c);
 243     return md;
 244  err:
 245     return NULL;
 246 }
 247
 248 void HMAC_CTX_set_flags(HMAC_CTX *ctx, unsigned long flags)
 249 {
 250     EVP_MD_CTX_set_flags(&ctx->i_ctx, flags);
 251     EVP_MD_CTX_set_flags(&ctx->o_ctx, flags);
 252     EVP_MD_CTX_set_flags(&ctx->md_ctx, flags);
 253 }