diff options
author | Matt Johnston <matt@ucc.asn.au> | 2006-03-08 12:58:00 +0000 |
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committer | Matt Johnston <matt@ucc.asn.au> | 2006-03-08 12:58:00 +0000 |
commit | c57e1d8def6e38d350da8b098a91806d405e952e (patch) | |
tree | dbd7bff4e514b7bfd2f2fe365eeaaea77ebafffd /src/mac/hmac/hmac_done.c |
Re-import libtomcrypt 1.05 for cleaner propagating.
From crypt-1.05.tar.bz2, SHA1 of 88250202bb51570dc64f7e8f1c943cda9479258f
--HG--
branch : libtomcrypt-orig
extra : convert_revision : 5c0c50e93111636ccf8deb758a689ad713797baf
Diffstat (limited to 'src/mac/hmac/hmac_done.c')
-rw-r--r-- | src/mac/hmac/hmac_done.c | 109 |
1 files changed, 109 insertions, 0 deletions
diff --git a/src/mac/hmac/hmac_done.c b/src/mac/hmac/hmac_done.c new file mode 100644 index 0000000..f64d044 --- /dev/null +++ b/src/mac/hmac/hmac_done.c @@ -0,0 +1,109 @@ +/* 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://libtomcrypt.org + */ +#include "tomcrypt.h" + +/** + @file hmac_done.c + HMAC support, terminate stream, Tom St Denis/Dobes Vandermeer +*/ + +#ifdef HMAC + +#define HMAC_BLOCKSIZE hash_descriptor[hash].blocksize + +/** + Terminate an HMAC session + @param hmac The HMAC state + @param out [out] The destination of the HMAC authentication tag + @param outlen [in/out] The max size and resulting size of the HMAC authentication tag + @return CRYPT_OK if successful +*/ +int hmac_done(hmac_state *hmac, unsigned char *out, unsigned long *outlen) +{ + unsigned char *buf, *isha; + unsigned long hashsize, i; + int hash, err; + + LTC_ARGCHK(hmac != NULL); + LTC_ARGCHK(out != NULL); + + /* test hash */ + hash = hmac->hash; + if((err = hash_is_valid(hash)) != CRYPT_OK) { + return err; + } + + /* get the hash message digest size */ + hashsize = hash_descriptor[hash].hashsize; + + /* allocate buffers */ + buf = XMALLOC(HMAC_BLOCKSIZE); + isha = XMALLOC(hashsize); + if (buf == NULL || isha == NULL) { + if (buf != NULL) { + XFREE(buf); + } + if (isha != NULL) { + XFREE(isha); + } + return CRYPT_MEM; + } + + /* Get the hash of the first HMAC vector plus the data */ + if ((err = hash_descriptor[hash].done(&hmac->md, isha)) != CRYPT_OK) { + goto LBL_ERR; + } + + /* Create the second HMAC vector vector for step (3) */ + for(i=0; i < HMAC_BLOCKSIZE; i++) { + buf[i] = hmac->key[i] ^ 0x5C; + } + + /* Now calculate the "outer" hash for step (5), (6), and (7) */ + if ((err = hash_descriptor[hash].init(&hmac->md)) != CRYPT_OK) { + goto LBL_ERR; + } + if ((err = hash_descriptor[hash].process(&hmac->md, buf, HMAC_BLOCKSIZE)) != CRYPT_OK) { + goto LBL_ERR; + } + if ((err = hash_descriptor[hash].process(&hmac->md, isha, hashsize)) != CRYPT_OK) { + goto LBL_ERR; + } + if ((err = hash_descriptor[hash].done(&hmac->md, buf)) != CRYPT_OK) { + goto LBL_ERR; + } + + /* copy to output */ + for (i = 0; i < hashsize && i < *outlen; i++) { + out[i] = buf[i]; + } + *outlen = i; + + err = CRYPT_OK; +LBL_ERR: + XFREE(hmac->key); +#ifdef LTC_CLEAN_STACK + zeromem(isha, hashsize); + zeromem(buf, hashsize); + zeromem(hmac, sizeof(*hmac)); +#endif + + XFREE(isha); + XFREE(buf); + + return err; +} + +#endif + +/* $Source: /cvs/libtom/libtomcrypt/src/mac/hmac/hmac_done.c,v $ */ +/* $Revision: 1.3 $ */ +/* $Date: 2005/05/05 14:35:58 $ */ |