diff options
Diffstat (limited to 'libtomcrypt/src/mac/omac/omac_process.c')
-rw-r--r-- | libtomcrypt/src/mac/omac/omac_process.c | 88 |
1 files changed, 88 insertions, 0 deletions
diff --git a/libtomcrypt/src/mac/omac/omac_process.c b/libtomcrypt/src/mac/omac/omac_process.c new file mode 100644 index 0000000..f4b96f5 --- /dev/null +++ b/libtomcrypt/src/mac/omac/omac_process.c @@ -0,0 +1,88 @@ +/* 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 omac_process.c + OMAC1 support, process data, Tom St Denis +*/ + + +#ifdef LTC_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; + if ((err = cipher_descriptor[omac->cipher_idx].ecb_encrypt(omac->prev, omac->prev, &omac->key)) != CRYPT_OK) { + return err; + } + } + 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]; + } + if ((err = cipher_descriptor[omac->cipher_idx].ecb_encrypt(omac->block, omac->prev, &omac->key)) != CRYPT_OK) { + return err; + } + 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: 1.9 $ */ +/* $Date: 2006/11/03 00:39:49 $ */ |