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/* LibTomCrypt, modular cryptographic library -- Tom St Denis
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* LibTomCrypt is a library that provides various cryptographic
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* algorithms in a highly modular and flexible manner.
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* The library is free for all purposes without any express
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* Tom St Denis, tomstdenis@gmail.com, http://libtomcrypt.org
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OMAC1 support, process data, Tom St Denis
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Process data through OMAC
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@param omac The OMAC state
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@param in The input data to send through OMAC
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@param inlen The length of the input (octets)
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@return CRYPT_OK if successful
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int omac_process(omac_state *omac, const unsigned char *in, unsigned long inlen)
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LTC_ARGCHK(omac != NULL);
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LTC_ARGCHK(in != NULL);
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if ((err = cipher_is_valid(omac->cipher_idx)) != CRYPT_OK) {
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if ((omac->buflen > (int)sizeof(omac->block)) || (omac->buflen < 0) ||
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(omac->blklen > (int)sizeof(omac->block)) || (omac->buflen > omac->blklen)) {
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return CRYPT_INVALID_ARG;
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if (omac->buflen == 0 && inlen > 16) {
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for (x = 0; x < (inlen - 16); x += 16) {
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for (y = 0; y < 16; y += sizeof(LTC_FAST_TYPE)) {
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*((LTC_FAST_TYPE*)(&omac->prev[y])) ^= *((LTC_FAST_TYPE*)(&in[y]));
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cipher_descriptor[omac->cipher_idx].ecb_encrypt(omac->prev, omac->prev, &omac->key);
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/* ok if the block is full we xor in prev, encrypt and replace prev */
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if (omac->buflen == omac->blklen) {
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for (x = 0; x < (unsigned long)omac->blklen; x++) {
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omac->block[x] ^= omac->prev[x];
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cipher_descriptor[omac->cipher_idx].ecb_encrypt(omac->block, omac->prev, &omac->key);
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n = MIN(inlen, (unsigned long)(omac->blklen - omac->buflen));
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XMEMCPY(omac->block + omac->buflen, in, n);
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/* $Source: /cvs/libtom/libtomcrypt/src/mac/omac/omac_process.c,v $ */
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/* $Revision: 1.6 $ */
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/* $Date: 2005/05/05 14:35:58 $ */