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 void HMAC_Init_ex(HMAC_CTX *ctx, const void *key, int len,
  65                   const EVP_MD *md, ENGINE *impl)
  66         {
  67         int i,j,reset=0;
  68         unsigned char pad[HMAC_MAX_MD_CBLOCK];
  69
  70         if (md != NULL)
  71                 {
  72                 reset=1;
  73                 ctx->md=md;
  74                 }
  75         else
  76                 md=ctx->md;
  77
  78         if (key != NULL)
  79                 {
  80                 reset=1;
  81                 j=EVP_MD_block_size(md);
  82                 OPENSSL_assert(j <= (int)sizeof(ctx->key));
  83                 if (j < len)
  84                         {
  85                         EVP_DigestInit_ex(&ctx->md_ctx,md, impl);
  86                         EVP_DigestUpdate(&ctx->md_ctx,key,len);
  87                         EVP_DigestFinal_ex(&(ctx->md_ctx),ctx->key,
  88                                 &ctx->key_length);
  89                         }
  90                 else
  91                         {
  92                         OPENSSL_assert(len>=0 && len<=(int)sizeof(ctx->key));
  93                         memcpy(ctx->key,key,len);
  94                         ctx->key_length=len;
  95                         }
  96                 if(ctx->key_length != HMAC_MAX_MD_CBLOCK)
  97                         memset(&ctx->key[ctx->key_length], 0,
  98                                 HMAC_MAX_MD_CBLOCK - ctx->key_length);
  99                 }
 100
 101         if (reset)
 102                 {
 103                 for (i=0; i<HMAC_MAX_MD_CBLOCK; i++)
 104                         pad[i]=0x36^ctx->key[i];
 105                 EVP_DigestInit_ex(&ctx->i_ctx,md, impl);
 106                 EVP_DigestUpdate(&ctx->i_ctx,pad,EVP_MD_block_size(md));
 107
 108                 for (i=0; i<HMAC_MAX_MD_CBLOCK; i++)
 109                         pad[i]=0x5c^ctx->key[i];
 110                 EVP_DigestInit_ex(&ctx->o_ctx,md, impl);
 111                 EVP_DigestUpdate(&ctx->o_ctx,pad,EVP_MD_block_size(md));
 112                 }
 113         EVP_MD_CTX_copy_ex(&ctx->md_ctx,&ctx->i_ctx);
 114         }
 115
 116 void HMAC_Init(HMAC_CTX *ctx, const void *key, int len,
 117                const EVP_MD *md)
 118         {
 119         if(key && md)
 120             HMAC_CTX_init(ctx);
 121         HMAC_Init_ex(ctx,key,len,md, NULL);
 122         }
 123
 124 void HMAC_Update(HMAC_CTX *ctx, const unsigned char *data, size_t len)
 125         {
 126         EVP_DigestUpdate(&ctx->md_ctx,data,len);
 127         }
 128
 129 void HMAC_Final(HMAC_CTX *ctx, unsigned char *md, unsigned int *len)
 130         {
 131         int j;
 132         unsigned int i;
 133         unsigned char buf[EVP_MAX_MD_SIZE];
 134
 135         j=EVP_MD_block_size(ctx->md);
 136
 137         EVP_DigestFinal_ex(&ctx->md_ctx,buf,&i);
 138         EVP_MD_CTX_copy_ex(&ctx->md_ctx,&ctx->o_ctx);
 139         EVP_DigestUpdate(&ctx->md_ctx,buf,i);
 140         EVP_DigestFinal_ex(&ctx->md_ctx,md,len);
 141         }
 142
 143 void HMAC_CTX_init(HMAC_CTX *ctx)
 144         {
 145         EVP_MD_CTX_init(&ctx->i_ctx);
 146         EVP_MD_CTX_init(&ctx->o_ctx);
 147         EVP_MD_CTX_init(&ctx->md_ctx);
 148         }
 149
 150 void HMAC_CTX_cleanup(HMAC_CTX *ctx)
 151         {
 152         EVP_MD_CTX_cleanup(&ctx->i_ctx);
 153         EVP_MD_CTX_cleanup(&ctx->o_ctx);
 154         EVP_MD_CTX_cleanup(&ctx->md_ctx);
 155         memset(ctx,0,sizeof *ctx);
 156         }
 157
 158 unsigned char *HMAC(const EVP_MD *evp_md, const void *key, int key_len,
 159                     const unsigned char *d, size_t n, unsigned char *md,
 160                     unsigned int *md_len)
 161         {
 162         HMAC_CTX c;
 163         static unsigned char m[EVP_MAX_MD_SIZE];
 164
 165         if (md == NULL) md=m;
 166         HMAC_CTX_init(&c);
 167         HMAC_Init(&c,key,key_len,evp_md);
 168         HMAC_Update(&c,d,n);
 169         HMAC_Final(&c,md,md_len);
 170         HMAC_CTX_cleanup(&c);
 171         return(md);
 172         }
 173