wolfssl/ctaocrypt/src/hmac.c
2011-06-02 11:06:25 -07:00

160 lines
4.2 KiB
C

/* hmac.c
*
* Copyright (C) 2006-2011 Sawtooth Consulting Ltd.
*
* This file is part of CyaSSL.
*
* CyaSSL is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* CyaSSL is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
*/
#ifndef NO_HMAC
#include "ctc_hmac.h"
#include "ctc_error.h"
static int InitHmac(Hmac* hmac, int type)
{
hmac->innerHashKeyed = 0;
hmac->macType = type;
if (!(type == MD5 || type == SHA || type == SHA256))
return BAD_FUNC_ARG;
if (type == MD5)
InitMd5(&hmac->hash.md5);
else if (type == SHA)
InitSha(&hmac->hash.sha);
#ifndef NO_SHA256
else if (type == SHA256)
InitSha256(&hmac->hash.sha256);
#endif
return 0;
}
void HmacSetKey(Hmac* hmac, int type, const byte* key, word32 length)
{
byte* ip = (byte*) hmac->ipad;
byte* op = (byte*) hmac->opad;
word32 i;
InitHmac(hmac, type);
if (length <= HMAC_BLOCK_SIZE)
XMEMCPY(ip, key, length);
else {
if (hmac->macType == MD5) {
Md5Update(&hmac->hash.md5, key, length);
Md5Final(&hmac->hash.md5, ip);
length = MD5_DIGEST_SIZE;
}
else if (hmac->macType == SHA) {
ShaUpdate(&hmac->hash.sha, key, length);
ShaFinal(&hmac->hash.sha, ip);
length = SHA_DIGEST_SIZE;
}
#ifndef NO_SHA256
else if (hmac->macType == SHA256) {
Sha256Update(&hmac->hash.sha256, key, length);
Sha256Final(&hmac->hash.sha256, ip);
length = SHA256_DIGEST_SIZE;
}
#endif
}
XMEMSET(ip + length, 0, HMAC_BLOCK_SIZE - length);
for(i = 0; i < HMAC_BLOCK_SIZE; i++) {
op[i] = ip[i] ^ OPAD;
ip[i] ^= IPAD;
}
}
static void HmacKeyInnerHash(Hmac* hmac)
{
if (hmac->macType == MD5)
Md5Update(&hmac->hash.md5, (byte*) hmac->ipad, HMAC_BLOCK_SIZE);
else if (hmac->macType == SHA)
ShaUpdate(&hmac->hash.sha, (byte*) hmac->ipad, HMAC_BLOCK_SIZE);
#ifndef NO_SHA256
else if (hmac->macType == SHA256)
Sha256Update(&hmac->hash.sha256, (byte*) hmac->ipad, HMAC_BLOCK_SIZE);
#endif
hmac->innerHashKeyed = 1;
}
void HmacUpdate(Hmac* hmac, const byte* msg, word32 length)
{
if (!hmac->innerHashKeyed)
HmacKeyInnerHash(hmac);
if (hmac->macType == MD5)
Md5Update(&hmac->hash.md5, msg, length);
else if (hmac->macType == SHA)
ShaUpdate(&hmac->hash.sha, msg, length);
#ifndef NO_SHA256
else if (hmac->macType == SHA256)
Sha256Update(&hmac->hash.sha256, msg, length);
#endif
}
void HmacFinal(Hmac* hmac, byte* hash)
{
if (!hmac->innerHashKeyed)
HmacKeyInnerHash(hmac);
if (hmac->macType == MD5) {
Md5Final(&hmac->hash.md5, (byte*) hmac->innerHash);
Md5Update(&hmac->hash.md5, (byte*) hmac->opad, HMAC_BLOCK_SIZE);
Md5Update(&hmac->hash.md5, (byte*) hmac->innerHash, MD5_DIGEST_SIZE);
Md5Final(&hmac->hash.md5, hash);
}
else if (hmac->macType ==SHA) {
ShaFinal(&hmac->hash.sha, (byte*) hmac->innerHash);
ShaUpdate(&hmac->hash.sha, (byte*) hmac->opad, HMAC_BLOCK_SIZE);
ShaUpdate(&hmac->hash.sha, (byte*) hmac->innerHash, SHA_DIGEST_SIZE);
ShaFinal(&hmac->hash.sha, hash);
}
#ifndef NO_SHA256
else if (hmac->macType ==SHA256) {
Sha256Final(&hmac->hash.sha256, (byte*) hmac->innerHash);
Sha256Update(&hmac->hash.sha256, (byte*) hmac->opad, HMAC_BLOCK_SIZE);
Sha256Update(&hmac->hash.sha256, (byte*) hmac->innerHash,
SHA256_DIGEST_SIZE);
Sha256Final(&hmac->hash.sha256, hash);
}
#endif
hmac->innerHashKeyed = 0;
}
#endif /* NO_HMAC */