Return to hmac.c CVS log

Up to [ELWIX - Embedded LightWeight unIX -] / embedaddon / axTLS / crypto

axTLS

    1: /*
    2:  * Copyright (c) 2007, Cameron Rich
    3:  * 
    4:  * All rights reserved.
    5:  * 
    6:  * Redistribution and use in source and binary forms, with or without 
    7:  * modification, are permitted provided that the following conditions are met:
    8:  *
    9:  * * Redistributions of source code must retain the above copyright notice, 
   10:  *   this list of conditions and the following disclaimer.
   11:  * * Redistributions in binary form must reproduce the above copyright notice, 
   12:  *   this list of conditions and the following disclaimer in the documentation 
   13:  *   and/or other materials provided with the distribution.
   14:  * * Neither the name of the axTLS project nor the names of its contributors 
   15:  *   may be used to endorse or promote products derived from this software 
   16:  *   without specific prior written permission.
   17:  *
   18:  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
   19:  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
   20:  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
   21:  * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
   22:  * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
   23:  * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
   24:  * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
   25:  * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
   26:  * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
   27:  * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
   28:  * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
   29:  */
   30: 
   31: /**
   32:  * HMAC implementation - This code was originally taken from RFC2104
   33:  * See http://www.ietf.org/rfc/rfc2104.txt and
   34:  * http://www.faqs.org/rfcs/rfc2202.html
   35:  */
   36: 
   37: #include <string.h>
   38: #include "os_port.h"
   39: #include "crypto.h"
   40: 
   41: /**
   42:  * Perform HMAC-MD5
   43:  * NOTE: does not handle keys larger than the block size.
   44:  */
   45: void hmac_md5(const uint8_t *msg, int length, const uint8_t *key, 
   46:         int key_len, uint8_t *digest)
   47: {
   48:     MD5_CTX context;
   49:     uint8_t k_ipad[64];
   50:     uint8_t k_opad[64];
   51:     int i;
   52: 
   53:     memset(k_ipad, 0, sizeof k_ipad);
   54:     memset(k_opad, 0, sizeof k_opad);
   55:     memcpy(k_ipad, key, key_len);
   56:     memcpy(k_opad, key, key_len);
   57: 
   58:     for (i = 0; i < 64; i++) 
   59:     {
   60:         k_ipad[i] ^= 0x36;
   61:         k_opad[i] ^= 0x5c;
   62:     }
   63: 
   64:     MD5_Init(&context);
   65:     MD5_Update(&context, k_ipad, 64);
   66:     MD5_Update(&context, msg, length);
   67:     MD5_Final(digest, &context);
   68:     MD5_Init(&context);
   69:     MD5_Update(&context, k_opad, 64);
   70:     MD5_Update(&context, digest, MD5_SIZE);
   71:     MD5_Final(digest, &context);
   72: }
   73: 
   74: /**
   75:  * Perform HMAC-SHA1
   76:  * NOTE: does not handle keys larger than the block size.
   77:  */
   78: void hmac_sha1(const uint8_t *msg, int length, const uint8_t *key, 
   79:         int key_len, uint8_t *digest)
   80: {
   81:     SHA1_CTX context;
   82:     uint8_t k_ipad[64];
   83:     uint8_t k_opad[64];
   84:     int i;
   85: 
   86:     memset(k_ipad, 0, sizeof k_ipad);
   87:     memset(k_opad, 0, sizeof k_opad);
   88:     memcpy(k_ipad, key, key_len);
   89:     memcpy(k_opad, key, key_len);
   90: 
   91:     for (i = 0; i < 64; i++) 
   92:     {
   93:         k_ipad[i] ^= 0x36;
   94:         k_opad[i] ^= 0x5c;
   95:     }
   96: 
   97:     SHA1_Init(&context);
   98:     SHA1_Update(&context, k_ipad, 64);
   99:     SHA1_Update(&context, msg, length);
  100:     SHA1_Final(digest, &context);
  101:     SHA1_Init(&context);
  102:     SHA1_Update(&context, k_opad, 64);
  103:     SHA1_Update(&context, digest, SHA1_SIZE);
  104:     SHA1_Final(digest, &context);
  105: }