diff options
Diffstat (limited to 'src/mac/pmac/pmac_process.c')
-rw-r--r-- | src/mac/pmac/pmac_process.c | 96 |
1 files changed, 96 insertions, 0 deletions
diff --git a/src/mac/pmac/pmac_process.c b/src/mac/pmac/pmac_process.c new file mode 100644 index 0000000..9ebd44e --- /dev/null +++ b/src/mac/pmac/pmac_process.c @@ -0,0 +1,96 @@ +/* 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 $ */ |