diff options
Diffstat (limited to 'core/lib/libtomcrypt/src/mac/hmac/hmac_init.c')
| -rw-r--r-- | core/lib/libtomcrypt/src/mac/hmac/hmac_init.c | 134 |
1 files changed, 134 insertions, 0 deletions
diff --git a/core/lib/libtomcrypt/src/mac/hmac/hmac_init.c b/core/lib/libtomcrypt/src/mac/hmac/hmac_init.c new file mode 100644 index 0000000..abc5bf3 --- /dev/null +++ b/core/lib/libtomcrypt/src/mac/hmac/hmac_init.c @@ -0,0 +1,134 @@ +/* + * Copyright (c) 2001-2007, Tom St Denis + * All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions are met: + * + * 1. Redistributions of source code must retain the above copyright notice, + * this list of conditions and the following disclaimer. + * + * 2. Redistributions in binary form must reproduce the above copyright notice, + * this list of conditions and the following disclaimer in the documentation + * and/or other materials provided with the distribution. + * + * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" + * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE + * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE + * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE + * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR + * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF + * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS + * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN + * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) + * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE + * POSSIBILITY OF SUCH DAMAGE. + */ + +/* LibTomCrypt, modular cryptographic library -- Tom St Denis + * + * LibTomCrypt is a library that provides various cryptographic + * algorithms in a highly modular and flexible manner. + * + * The library is free for all purposes without any express + * guarantee it works. + * + * Tom St Denis, tomstdenis@gmail.com, http://libtom.org + */ +#include "tomcrypt.h" + +/** + @file hmac_init.c + LTC_HMAC support, initialize state, Tom St Denis/Dobes Vandermeer +*/ + +#ifdef LTC_HMAC + +#define LTC_HMAC_BLOCKSIZE hash_descriptor[hash]->blocksize + +/** + Initialize an LTC_HMAC context. + @param hmac The LTC_HMAC state + @param hash The index of the hash you want to use + @param key The secret key + @param keylen The length of the secret key (octets) + @return CRYPT_OK if successful +*/ +int hmac_init(hmac_state *hmac, int hash, const unsigned char *key, unsigned long keylen) +{ + unsigned char *buf; + unsigned long hashsize; + unsigned long i, z; + int err; + + LTC_ARGCHK(hmac != NULL); + LTC_ARGCHK(key != NULL); + + /* valid hash? */ + if ((err = hash_is_valid(hash)) != CRYPT_OK) { + return err; + } + hmac->hash = hash; + hashsize = hash_descriptor[hash]->hashsize; + + /* valid key length? */ + if (keylen == 0) { + return CRYPT_INVALID_KEYSIZE; + } + + /* allocate ram for buf */ + buf = XMALLOC(LTC_HMAC_BLOCKSIZE); + if (buf == NULL) { + return CRYPT_MEM; + } + + /* check hash blocks fits */ + if (sizeof(hmac->key) < LTC_HMAC_BLOCKSIZE) { + err = CRYPT_BUFFER_OVERFLOW; + goto LBL_ERR; + } + + /* (1) make sure we have a large enough key */ + if(keylen > LTC_HMAC_BLOCKSIZE) { + z = LTC_HMAC_BLOCKSIZE; + if ((err = hash_memory(hash, key, keylen, hmac->key, &z)) != CRYPT_OK) { + goto LBL_ERR; + } + keylen = hashsize; + } else { + XMEMCPY(hmac->key, key, (size_t)keylen); + } + + if(keylen < LTC_HMAC_BLOCKSIZE) { + zeromem((hmac->key) + keylen, (size_t)(LTC_HMAC_BLOCKSIZE - keylen)); + } + + /* Create the initial vector for step (3) */ + for(i=0; i < LTC_HMAC_BLOCKSIZE; i++) { + buf[i] = hmac->key[i] ^ 0x36; + } + + /* Pre-pend that to the hash data */ + if ((err = hash_descriptor[hash]->init(&hmac->md)) != CRYPT_OK) { + goto LBL_ERR; + } + + if ((err = hash_descriptor[hash]->process(&hmac->md, buf, LTC_HMAC_BLOCKSIZE)) != CRYPT_OK) { + goto LBL_ERR; + } + goto done; +LBL_ERR: +done: +#ifdef LTC_CLEAN_STACK + zeromem(buf, LTC_HMAC_BLOCKSIZE); +#endif + + XFREE(buf); + return err; +} + +#endif + +/* $Source: /cvs/libtom/libtomcrypt/src/mac/hmac/hmac_init.c,v $ */ +/* $Revision: 1.7 $ */ +/* $Date: 2007/05/12 14:37:41 $ */ |