Line data    Source code

       1             : /* FreeTDS - Library of routines accessing Sybase and Microsoft databases
       2             :  * Copyright (C) 2008  Frediano Ziglio
       3             :  *
       4             :  * This library is free software; you can redistribute it and/or
       5             :  * modify it under the terms of the GNU Library General Public
       6             :  * License as published by the Free Software Foundation; either
       7             :  * version 2 of the License, or (at your option) any later version.
       8             :  *
       9             :  * This library is distributed in the hope that it will be useful,
      10             :  * but WITHOUT ANY WARRANTY; without even the implied warranty of
      11             :  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
      12             :  * Library General Public License for more details.
      13             :  *
      14             :  * You should have received a copy of the GNU Library General Public
      15             :  * License along with this library; if not, write to the
      16             :  * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
      17             :  * Boston, MA 02111-1307, USA.
      18             :  */
      19             : 
      20             : #include <config.h>
      21             : 
      22             : #if HAVE_STRING_H
      23             : #include <string.h>
      24             : #endif /* HAVE_STRING_H */
      25             : 
      26             : #include <tds_sysdep_public.h>
      27             : #include <freetds/utils/md5.h>
      28             : #include <freetds/utils/hmac_md5.h>
      29             : #include <memory.h>
      30             : 
      31             : /**
      32             :  * Calculates the HMAC-MD5 hash of the given data using the specified
      33             :  * hashing key.
      34             :  *
      35             :  * @param key      The hashing key.
      36             :  * @param data     The data for which the hash will be calculated. 
      37             :  * @param data_len data length. 
      38             :  * @param digest   The HMAC-MD5 hash of the given data.
      39             :  */
      40        2142 : void hmac_md5(const unsigned char key[16],
      41             :               const unsigned char* data, size_t data_len,
      42             :               unsigned char* digest)
      43             : {
      44             :         int i;
      45             :         MD5_CTX ctx;
      46             :         unsigned char k_ipad[64];
      47             :         unsigned char k_opad[64];
      48             : 
      49             :         /* compute ipad and opad */
      50        2142 :         memset(k_ipad, 0x36, sizeof(k_ipad));
      51        2142 :         memset(k_opad, 0x5c, sizeof(k_opad));
      52       36414 :         for (i=0; i<16; ++i) {
      53       34272 :                 k_ipad[i] ^= key[i];
      54       34272 :                 k_opad[i] ^= key[i];
      55             :         }
      56             : 
      57        2142 :         MD5Init(&ctx);
      58        2142 :         MD5Update(&ctx, k_ipad, 64);
      59        2142 :         if (data_len != 0)
      60        1067 :                 MD5Update(&ctx, data, data_len);
      61        2142 :         MD5Final(&ctx, digest);
      62             : 
      63        2142 :         MD5Init(&ctx);
      64        2142 :         MD5Update(&ctx, k_opad, 64);
      65        2142 :         MD5Update(&ctx, digest, 16);
      66        2142 :         MD5Final(&ctx, digest);
      67        2142 : }
      68             :