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/* 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 pmac_process.c
PMAC implementation, process data, by Tom St Denis
*/
#ifdef PMAC
/**
Process data in a PMAC stream
@param pmac The PMAC state
@param in The data to send through PMAC
@param inlen The length of the data to send through PMAC
@return CRYPT_OK if successful
*/
int pmac_process(pmac_state *pmac, const unsigned char *in, unsigned long inlen)
{
int err, n;
unsigned long x;
unsigned char Z[MAXBLOCKSIZE];
LTC_ARGCHK(pmac != NULL);
LTC_ARGCHK(in != NULL);
if ((err = cipher_is_valid(pmac->cipher_idx)) != CRYPT_OK) {
return err;
}
if ((pmac->buflen > (int)sizeof(pmac->block)) || (pmac->buflen < 0) ||
(pmac->block_len > (int)sizeof(pmac->block)) || (pmac->buflen > pmac->block_len)) {
return CRYPT_INVALID_ARG;
}
#ifdef LTC_FAST
if (pmac->buflen == 0 && inlen > 16) {
unsigned long y;
for (x = 0; x < (inlen - 16); x += 16) {
pmac_shift_xor(pmac);
for (y = 0; y < 16; y += sizeof(LTC_FAST_TYPE)) {
*((LTC_FAST_TYPE*)(&Z[y])) = *((LTC_FAST_TYPE*)(&in[y])) ^ *((LTC_FAST_TYPE*)(&pmac->Li[y]));
}
cipher_descriptor[pmac->cipher_idx].ecb_encrypt(Z, Z, &pmac->key);
for (y = 0; y < 16; y += sizeof(LTC_FAST_TYPE)) {
*((LTC_FAST_TYPE*)(&pmac->checksum[y])) ^= *((LTC_FAST_TYPE*)(&Z[y]));
}
in += 16;
}
inlen -= x;
}
#endif
while (inlen != 0) {
/* ok if the block is full we xor in prev, encrypt and replace prev */
if (pmac->buflen == pmac->block_len) {
pmac_shift_xor(pmac);
for (x = 0; x < (unsigned long)pmac->block_len; x++) {
Z[x] = pmac->Li[x] ^ pmac->block[x];
}
cipher_descriptor[pmac->cipher_idx].ecb_encrypt(Z, Z, &pmac->key);
for (x = 0; x < (unsigned long)pmac->block_len; x++) {
pmac->checksum[x] ^= Z[x];
}
pmac->buflen = 0;
}
/* add bytes */
n = MIN(inlen, (unsigned long)(pmac->block_len - pmac->buflen));
XMEMCPY(pmac->block + pmac->buflen, in, n);
pmac->buflen += n;
inlen -= n;
in += n;
}
#ifdef LTC_CLEAN_STACK
zeromem(Z, sizeof(Z));
#endif
return CRYPT_OK;
}
#endif
/* $Source: /cvs/libtom/libtomcrypt/src/mac/pmac/pmac_process.c,v $ */
/* $Revision: 1.5 $ */
/* $Date: 2005/05/05 14:35:59 $ */
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