/* 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.com
*/
#include "tomcrypt.h"
/**
@file xcbc_process.c
XCBC Support, process blocks with XCBC
*/
#ifdef LTC_XCBC
/** Process data through XCBC-MAC
@param xcbc The XCBC-MAC state
@param in Input data to process
@param inlen Length of input in octets
Return CRYPT_OK on success
*/
int xcbc_process(xcbc_state *xcbc, const unsigned char *in, unsigned long inlen)
{
int err;
#ifdef LTC_FAST
int x;
#endif
LTC_ARGCHK(xcbc != NULL);
LTC_ARGCHK(in != NULL);
/* check structure */
if ((err = cipher_is_valid(xcbc->cipher)) != CRYPT_OK) {
return err;
}
if ((xcbc->blocksize > cipher_descriptor[xcbc->cipher].block_length) || (xcbc->blocksize < 0) ||
(xcbc->buflen > xcbc->blocksize) || (xcbc->buflen < 0)) {
return CRYPT_INVALID_ARG;
}
#ifdef LTC_FAST
if (xcbc->buflen == 0) {
while (inlen > (unsigned long)xcbc->blocksize) {
for (x = 0; x < xcbc->blocksize; x += sizeof(LTC_FAST_TYPE)) {
*((LTC_FAST_TYPE*)&(xcbc->IV[x])) ^= *((LTC_FAST_TYPE*)&(in[x]));
}
cipher_descriptor[xcbc->cipher].ecb_encrypt(xcbc->IV, xcbc->IV, &xcbc->key);
in += xcbc->blocksize;
inlen -= xcbc->blocksize;
}
}
#endif
while (inlen) {
if (xcbc->buflen == xcbc->blocksize) {
cipher_descriptor[xcbc->cipher].ecb_encrypt(xcbc->IV, xcbc->IV, &xcbc->key);
xcbc->buflen = 0;
}
xcbc->IV[xcbc->buflen++] ^= *in++;
--inlen;
}
return CRYPT_OK;
}
#endif
/* $Source: /cvs/libtom/libtomcrypt/src/mac/xcbc/xcbc_process.c,v $ */
/* $Revision: 1.9 $ */
/* $Date: 2006/11/09 22:43:52 $ */