| /* 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 omac_process.c |
| OMAC1 support, process data, Tom St Denis |
| */ |
| |
| |
| #ifdef OMAC |
| |
| /** |
| Process data through OMAC |
| @param omac The OMAC state |
| @param in The input data to send through OMAC |
| @param inlen The length of the input (octets) |
| @return CRYPT_OK if successful |
| */ |
| int omac_process(omac_state *omac, const unsigned char *in, unsigned long inlen) |
| { |
| unsigned long n, x; |
| int err; |
| |
| LTC_ARGCHK(omac != NULL); |
| LTC_ARGCHK(in != NULL); |
| if ((err = cipher_is_valid(omac->cipher_idx)) != CRYPT_OK) { |
| return err; |
| } |
| |
| if ((omac->buflen > (int)sizeof(omac->block)) || (omac->buflen < 0) || |
| (omac->blklen > (int)sizeof(omac->block)) || (omac->buflen > omac->blklen)) { |
| return CRYPT_INVALID_ARG; |
| } |
| |
| #ifdef LTC_FAST |
| if (omac->buflen == 0 && inlen > 16) { |
| int y; |
| for (x = 0; x < (inlen - 16); x += 16) { |
| for (y = 0; y < 16; y += sizeof(LTC_FAST_TYPE)) { |
| *((LTC_FAST_TYPE*)(&omac->prev[y])) ^= *((LTC_FAST_TYPE*)(&in[y])); |
| } |
| in += 16; |
| cipher_descriptor[omac->cipher_idx].ecb_encrypt(omac->prev, omac->prev, &omac->key); |
| } |
| inlen -= x; |
| } |
| #endif |
| |
| while (inlen != 0) { |
| /* ok if the block is full we xor in prev, encrypt and replace prev */ |
| if (omac->buflen == omac->blklen) { |
| for (x = 0; x < (unsigned long)omac->blklen; x++) { |
| omac->block[x] ^= omac->prev[x]; |
| } |
| cipher_descriptor[omac->cipher_idx].ecb_encrypt(omac->block, omac->prev, &omac->key); |
| omac->buflen = 0; |
| } |
| |
| /* add bytes */ |
| n = MIN(inlen, (unsigned long)(omac->blklen - omac->buflen)); |
| XMEMCPY(omac->block + omac->buflen, in, n); |
| omac->buflen += n; |
| inlen -= n; |
| in += n; |
| } |
| |
| return CRYPT_OK; |
| } |
| |
| #endif |
| |
| |
| /* $Source: /cvs/libtom/libtomcrypt/src/mac/omac/omac_process.c,v $ */ |
| /* $Revision: 1.6 $ */ |
| /* $Date: 2005/05/05 14:35:58 $ */ |