crypto/openssl/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     /* If we are changing MD then we must have a key */
 101     if (md != NULL && md != ctx->md && (key == NULL || len < 0))
 102         return 0;
 103
 104     if (md != NULL) {
 105         reset = 1;
 106         ctx->md = md;
 107     } else if (ctx->md) {
 108         md = ctx->md;
 109     } else {
 110         return 0;
 111     }
 112
 113     if (key != NULL) {
 114         reset = 1;
 115         j = EVP_MD_block_size(md);
 116         OPENSSL_assert(j <= (int)sizeof(ctx->key));
 117         if (j < len) {
 118             if (!EVP_DigestInit_ex(&ctx->md_ctx, md, impl))
 119                 goto err;
 120             if (!EVP_DigestUpdate(&ctx->md_ctx, key, len))
 121                 goto err;
 122             if (!EVP_DigestFinal_ex(&(ctx->md_ctx), ctx->key,
 123                                     &ctx->key_length))
 124                 goto err;
 125         } else {
 126             if (len < 0 || len > (int)sizeof(ctx->key))
 127                 return 0;
 128             memcpy(ctx->key, key, len);
 129             ctx->key_length = len;
 130         }
 131         if (ctx->key_length != HMAC_MAX_MD_CBLOCK)
 132             memset(&ctx->key[ctx->key_length], 0,
 133                    HMAC_MAX_MD_CBLOCK - ctx->key_length);
 134     }
 135
 136     if (reset) {
 137         for (i = 0; i < HMAC_MAX_MD_CBLOCK; i++)
 138             pad[i] = 0x36 ^ ctx->key[i];
 139         if (!EVP_DigestInit_ex(&ctx->i_ctx, md, impl))
 140             goto err;
 141         if (!EVP_DigestUpdate(&ctx->i_ctx, pad, EVP_MD_block_size(md)))
 142             goto err;
 143
 144         for (i = 0; i < HMAC_MAX_MD_CBLOCK; i++)
 145             pad[i] = 0x5c ^ ctx->key[i];
 146         if (!EVP_DigestInit_ex(&ctx->o_ctx, md, impl))
 147             goto err;
 148         if (!EVP_DigestUpdate(&ctx->o_ctx, pad, EVP_MD_block_size(md)))
 149             goto err;
 150     }
 151     if (!EVP_MD_CTX_copy_ex(&ctx->md_ctx, &ctx->i_ctx))
 152         goto err;
 153     return 1;
 154  err:
 155     return 0;
 156 }
 157
 158 int HMAC_Init(HMAC_CTX *ctx, const void *key, int len, const EVP_MD *md)
 159 {
 160     if (key && md)
 161         HMAC_CTX_init(ctx);
 162     return HMAC_Init_ex(ctx, key, len, md, NULL);
 163 }
 164
 165 int HMAC_Update(HMAC_CTX *ctx, const unsigned char *data, size_t len)
 166 {
 167 #ifdef OPENSSL_FIPS
 168     if (FIPS_mode() && !ctx->i_ctx.engine)
 169         return FIPS_hmac_update(ctx, data, len);
 170 #endif
 171     if (!ctx->md)
 172         return 0;
 173
 174     return EVP_DigestUpdate(&ctx->md_ctx, data, len);
 175 }
 176
 177 int HMAC_Final(HMAC_CTX *ctx, unsigned char *md, unsigned int *len)
 178 {
 179     unsigned int i;
 180     unsigned char buf[EVP_MAX_MD_SIZE];
 181 #ifdef OPENSSL_FIPS
 182     if (FIPS_mode() && !ctx->i_ctx.engine)
 183         return FIPS_hmac_final(ctx, md, len);
 184 #endif
 185
 186     if (!ctx->md)
 187         goto err;
 188
 189     if (!EVP_DigestFinal_ex(&ctx->md_ctx, buf, &i))
 190         goto err;
 191     if (!EVP_MD_CTX_copy_ex(&ctx->md_ctx, &ctx->o_ctx))
 192         goto err;
 193     if (!EVP_DigestUpdate(&ctx->md_ctx, buf, i))
 194         goto err;
 195     if (!EVP_DigestFinal_ex(&ctx->md_ctx, md, len))
 196         goto err;
 197     return 1;
 198  err:
 199     return 0;
 200 }
 201
 202 void HMAC_CTX_init(HMAC_CTX *ctx)
 203 {
 204     EVP_MD_CTX_init(&ctx->i_ctx);
 205     EVP_MD_CTX_init(&ctx->o_ctx);
 206     EVP_MD_CTX_init(&ctx->md_ctx);
 207     ctx->md = NULL;
 208 }
 209
 210 int HMAC_CTX_copy(HMAC_CTX *dctx, HMAC_CTX *sctx)
 211 {
 212     if (!EVP_MD_CTX_copy(&dctx->i_ctx, &sctx->i_ctx))
 213         goto err;
 214     if (!EVP_MD_CTX_copy(&dctx->o_ctx, &sctx->o_ctx))
 215         goto err;
 216     if (!EVP_MD_CTX_copy(&dctx->md_ctx, &sctx->md_ctx))
 217         goto err;
 218     memcpy(dctx->key, sctx->key, HMAC_MAX_MD_CBLOCK);
 219     dctx->key_length = sctx->key_length;
 220     dctx->md = sctx->md;
 221     return 1;
 222  err:
 223     return 0;
 224 }
 225
 226 void HMAC_CTX_cleanup(HMAC_CTX *ctx)
 227 {
 228 #ifdef OPENSSL_FIPS
 229     if (FIPS_mode() && !ctx->i_ctx.engine) {
 230         FIPS_hmac_ctx_cleanup(ctx);
 231         return;
 232     }
 233 #endif
 234     EVP_MD_CTX_cleanup(&ctx->i_ctx);
 235     EVP_MD_CTX_cleanup(&ctx->o_ctx);
 236     EVP_MD_CTX_cleanup(&ctx->md_ctx);
 237     memset(ctx, 0, sizeof *ctx);
 238 }
 239
 240 unsigned char *HMAC(const EVP_MD *evp_md, const void *key, int key_len,
 241                     const unsigned char *d, size_t n, unsigned char *md,
 242                     unsigned int *md_len)
 243 {
 244     HMAC_CTX c;
 245     static unsigned char m[EVP_MAX_MD_SIZE];
 246
 247     if (md == NULL)
 248         md = m;
 249     HMAC_CTX_init(&c);
 250     if (!HMAC_Init(&c, key, key_len, evp_md))
 251         goto err;
 252     if (!HMAC_Update(&c, d, n))
 253         goto err;
 254     if (!HMAC_Final(&c, md, md_len))
 255         goto err;
 256     HMAC_CTX_cleanup(&c);
 257     return md;
 258  err:
 259     HMAC_CTX_cleanup(&c);
 260     return NULL;
 261 }
 262
 263 void HMAC_CTX_set_flags(HMAC_CTX *ctx, unsigned long flags)
 264 {
 265     EVP_MD_CTX_set_flags(&ctx->i_ctx, flags);
 266     EVP_MD_CTX_set_flags(&ctx->o_ctx, flags);
 267     EVP_MD_CTX_set_flags(&ctx->md_ctx, flags);
 268 }