release/src-rt/bcmcrypto/hmac.c

   1 /*
   2  * Function: hmac_md5
   3  * From rfc2104.txt
   4  *
   5  * $Id: hmac.c,v 1.16 2009-04-13 16:25:16 Exp $
   6  */
   7
   8 /*
   9  *   Copyright (C) The Internet Society (2001).  All Rights Reserved.
  10  *
  11  *   This document and translations of it may be copied and furnished to
  12  *   others, and derivative works that comment on or otherwise explain it
  13  *   or assist in its implementation may be prepared, copied, published
  14  *   and distributed, in whole or in part, without restriction of any
  15  *   kind, provided that the above copyright notice and this paragraph are
  16  *   included on all such copies and derivative works.  However, this
  17  *   document itself may not be modified in any way, such as by removing
  18  *   the copyright notice or references to the Internet Society or other
  19  *   Internet organizations, except as needed for the purpose of
  20  *   developing Internet standards in which case the procedures for
  21  *   copyrights defined in the Internet Standards process must be
  22  *   followed, or as required to translate it into languages other than
  23  *   English.
  24  *
  25  *   The limited permissions granted above are perpetual and will not be
  26  *   revoked by the Internet Society or its successors or assigns.
  27  *
  28  *   This document and the information contained herein is provided on an
  29  *   "AS IS" basis and THE INTERNET SOCIETY AND THE INTERNET ENGINEERING
  30  *   TASK FORCE DISCLAIMS ALL WARRANTIES, EXPRESS OR IMPLIED, INCLUDING
  31  *   BUT NOT LIMITED TO ANY WARRANTY THAT THE USE OF THE INFORMATION
  32  *   HEREIN WILL NOT INFRINGE ANY RIGHTS OR ANY IMPLIED WARRANTIES OF
  33  *   MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE.
  34  *
  35  * Copyright (C) 2010, Broadcom Corporation
  36  * All Rights Reserved.
  37  *
  38  * This is UNPUBLISHED PROPRIETARY SOURCE CODE of Broadcom Corporation;
  39  * the contents of this file may not be disclosed to third parties, copied
  40  * or duplicated in any form, in whole or in part, without the prior
  41  * written permission of Broadcom Corporation.
  42  *
  43  * $Id: hmac.c,v 1.16 2009-04-13 16:25:16 Exp $
  44  */
  45
  46
  47 #include <bcmcrypto/md5.h>
  48
  49 #ifdef BCMDRIVER
  50 #if !defined(BCMSUP_PSK)
  51 #error "BCMSUP_PSK or BCMCCX must be defined to compile hmac.c for driver!"
  52 #endif
  53 #include <osl.h>
  54 #else
  55 #if defined(__GNUC__)
  56 extern void bcopy(const void *src, void *dst, int len);
  57 extern void bzero(void *b, int len);
  58 #else
  59 #define bcopy(src, dst, len)    memcpy((dst), (src), (len))
  60 #define bzero(b, len)           memset((b), 0, (len))
  61 #endif
  62 #endif  /* BCMDRIVER */
  63
  64
  65 extern void BCMROMFN(hmac_md5)(unsigned char *text, int text_len, unsigned char *key,
  66                                int key_len, unsigned char *digest);
  67
  68 /* text         pointer to data stream */
  69 /* text_len     length of data stream */
  70 /* key          pointer to authentication key */
  71 /* key_len      length of authentication key */
  72 /* digest       caller digest to be filled in */
  73 void
  74 BCMROMFN(hmac_md5)(unsigned char *text, int text_len, unsigned char *key,
  75                    int key_len, unsigned char *digest)
  76 {
  77         MD5_CTX context;
  78         unsigned char k_ipad[65];    /* inner padding -
  79                                       * key XORd with ipad
  80                                       */
  81         unsigned char k_opad[65];    /* outer padding -
  82                                       * key XORd with opad
  83                                       */
  84         unsigned char tk[16];
  85         int i;
  86         /* if key is longer than 64 bytes reset it to key=MD5(key) */
  87         if (key_len > 64) {
  88
  89                 MD5_CTX      tctx;
  90
  91                 MD5Init(&tctx);
  92                 MD5Update(&tctx, key, key_len);
  93                 MD5Final(tk, &tctx);
  94
  95                 key = tk;
  96                 key_len = 16;
  97         }
  98
  99         /*
 100          * the HMAC_MD5 transform looks like:
 101          *
 102          * MD5(K XOR opad, MD5(K XOR ipad, text))
 103          *
 104          * where K is an n byte key
 105          * ipad is the byte 0x36 repeated 64 times
 106
 107          * opad is the byte 0x5c repeated 64 times
 108          * and text is the data being protected
 109          */
 110
 111         /* start out by storing key in pads */
 112         bzero(k_ipad, sizeof(k_ipad));
 113         bzero(k_opad, sizeof(k_opad));
 114         bcopy(key, k_ipad, key_len);
 115         bcopy(key, k_opad, key_len);
 116
 117         /* XOR key with ipad and opad values */
 118         for (i = 0; i < 64; i++) {
 119                 k_ipad[i] ^= 0x36;
 120                 k_opad[i] ^= 0x5c;
 121         }
 122         /*
 123          * perform inner MD5
 124          */
 125         MD5Init(&context);                   /* init context for 1st pass */
 126         MD5Update(&context, k_ipad, 64);     /* start with inner pad */
 127         MD5Update(&context, text, text_len); /* then text of datagram */
 128         MD5Final(digest, &context);          /* finish up 1st pass */
 129         /*
 130          * perform outer MD5
 131          */
 132         MD5Init(&context);                   /* init context for 2nd pass */
 133         MD5Update(&context, k_opad, 64);     /* start with outer pad */
 134         MD5Update(&context, digest, 16);     /* then results of 1st hash */
 135         MD5Final(digest, &context);          /* finish up 2nd pass */
 136 }