wolfssl/ctaocrypt/src/hmac.c

/* hmac.c
 *
 * Copyright (C) 2006-2012 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
 */

#ifdef HAVE_CONFIG_H
    #include <config.h>
#endif

#ifndef NO_HMAC

#include <cyassl/ctaocrypt/hmac.h>
#include <cyassl/ctaocrypt/error.h>


static int InitHmac(Hmac* hmac, int type)
{
    hmac->innerHashKeyed = 0;
    hmac->macType = (byte)type;

    if (!(type == MD5 || type == SHA || type == SHA256 || type == SHA384))
        return BAD_FUNC_ARG;

    switch (type) {
        #ifndef NO_MD5
        case MD5:
            InitMd5(&hmac->hash.md5);
        break;
        #endif

        case SHA:
            InitSha(&hmac->hash.sha);
        break;
        
        #ifndef NO_SHA256
        case SHA256:
            InitSha256(&hmac->hash.sha256);
        break;
        #endif
        
        #ifdef CYASSL_SHA384
        case SHA384:
            InitSha384(&hmac->hash.sha384);
        break;
        #endif
        
        default:
        break;
    }

    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, hmac_block_size = SHA_BLOCK_SIZE;

    InitHmac(hmac, type);

    switch (hmac->macType) {
        #ifndef NO_MD5
        case MD5:
        {
            hmac_block_size = MD5_BLOCK_SIZE;
            if (length <= MD5_BLOCK_SIZE) {
                XMEMCPY(ip, key, length);
            }
            else {
                Md5Update(&hmac->hash.md5, key, length);
                Md5Final(&hmac->hash.md5, ip);
                length = MD5_DIGEST_SIZE;
            }
        }
        break;
        #endif

        case SHA:
        {
            if (length <= SHA_BLOCK_SIZE) {
                XMEMCPY(ip, key, length);
            }
            else {
                ShaUpdate(&hmac->hash.sha, key, length);
                ShaFinal(&hmac->hash.sha, ip);
                length = SHA_DIGEST_SIZE;
            }
        }
        break;

        #ifndef NO_SHA256
        case SHA256:
        {
    		hmac_block_size = SHA256_BLOCK_SIZE;
            if (length <= SHA256_BLOCK_SIZE) {
                XMEMCPY(ip, key, length);
            }
            else {
                Sha256Update(&hmac->hash.sha256, key, length);
                Sha256Final(&hmac->hash.sha256, ip);
                length = SHA256_DIGEST_SIZE;
            }
        }
        break;
        #endif

        #ifdef CYASSL_SHA384
        case SHA384:
        {
            hmac_block_size = SHA384_BLOCK_SIZE;
            if (length <= SHA384_BLOCK_SIZE) {
                XMEMCPY(ip, key, length);
            }
            else {
                Sha384Update(&hmac->hash.sha384, key, length);
                Sha384Final(&hmac->hash.sha384, ip);
                length = SHA384_DIGEST_SIZE;
            }
        }
        break;
        #endif

        default:
        break;
    }
    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)
{
    switch (hmac->macType) {
        #ifndef NO_MD5
        case MD5:
            Md5Update(&hmac->hash.md5, (byte*) hmac->ipad, MD5_BLOCK_SIZE);
        break;
        #endif

        case SHA:
            ShaUpdate(&hmac->hash.sha, (byte*) hmac->ipad, SHA_BLOCK_SIZE);
        break;

        #ifndef NO_SHA256
        case SHA256:
            Sha256Update(&hmac->hash.sha256,
                                         (byte*) hmac->ipad, SHA256_BLOCK_SIZE);
        break;
        #endif

        #ifdef CYASSL_SHA384
        case SHA384:
            Sha384Update(&hmac->hash.sha384,
                                         (byte*) hmac->ipad, SHA384_BLOCK_SIZE);
        break;
        #endif

        default:
        break;
    }

    hmac->innerHashKeyed = 1;
}


void HmacUpdate(Hmac* hmac, const byte* msg, word32 length)
{
    if (!hmac->innerHashKeyed)
        HmacKeyInnerHash(hmac);

    switch (hmac->macType) {
        #ifndef NO_MD5
        case MD5:
            Md5Update(&hmac->hash.md5, msg, length);
        break;
        #endif

        case SHA:
            ShaUpdate(&hmac->hash.sha, msg, length);
        break;

        #ifndef NO_SHA256
        case SHA256:
            Sha256Update(&hmac->hash.sha256, msg, length);
        break;
        #endif

        #ifdef CYASSL_SHA384
        case SHA384:
            Sha384Update(&hmac->hash.sha384, msg, length);
        break;
        #endif

        default:
        break;
    }

}


void HmacFinal(Hmac* hmac, byte* hash)
{
    if (!hmac->innerHashKeyed)
        HmacKeyInnerHash(hmac);

    switch (hmac->macType) {
        #ifndef NO_MD5
        case MD5:
        {
            Md5Final(&hmac->hash.md5, (byte*) hmac->innerHash);

            Md5Update(&hmac->hash.md5, (byte*) hmac->opad, MD5_BLOCK_SIZE);
            Md5Update(&hmac->hash.md5,
                                     (byte*) hmac->innerHash, MD5_DIGEST_SIZE);

            Md5Final(&hmac->hash.md5, hash);
        }
        break;
        #endif

        case SHA:
        {
            ShaFinal(&hmac->hash.sha, (byte*) hmac->innerHash);

            ShaUpdate(&hmac->hash.sha, (byte*) hmac->opad, SHA_BLOCK_SIZE);
            ShaUpdate(&hmac->hash.sha,
                                     (byte*) hmac->innerHash, SHA_DIGEST_SIZE);

            ShaFinal(&hmac->hash.sha, hash);
        }
        break;

        #ifndef NO_SHA256
        case SHA256:
        {
            Sha256Final(&hmac->hash.sha256, (byte*) hmac->innerHash);

            Sha256Update(&hmac->hash.sha256,
                                (byte*) hmac->opad, SHA256_BLOCK_SIZE);
            Sha256Update(&hmac->hash.sha256,
                                (byte*) hmac->innerHash, SHA256_DIGEST_SIZE);

            Sha256Final(&hmac->hash.sha256, hash);
        }
        break;
        #endif

        #ifdef CYASSL_SHA384
        case SHA384:
        {
            Sha384Final(&hmac->hash.sha384, (byte*) hmac->innerHash);

            Sha384Update(&hmac->hash.sha384,
                                 (byte*) hmac->opad, SHA384_BLOCK_SIZE);
            Sha384Update(&hmac->hash.sha384,
                                 (byte*) hmac->innerHash, SHA384_DIGEST_SIZE);

            Sha384Final(&hmac->hash.sha384, hash);
        }
        break;
        #endif

        default:
        break;
    }

    hmac->innerHashKeyed = 0;
}


#endif /* NO_HMAC */