Mercurial > dropbear
diff src/mac/omac/omac_process.c @ 192:9cc34777b479 libtomcrypt
propagate from branch 'au.asn.ucc.matt.ltc-orig' (head 9ba8f01f44320e9cb9f19881105ae84f84a43ea9)
to branch 'au.asn.ucc.matt.dropbear.ltc' (head dbf51c569bc34956ad948e4cc87a0eeb2170b768)
author | Matt Johnston <matt@ucc.asn.au> |
---|---|
date | Sun, 08 May 2005 06:36:47 +0000 |
parents | 1c15b283127b |
children | 39d5d58461d6 |
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--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/src/mac/omac/omac_process.c Sun May 08 06:36:47 2005 +0000 @@ -0,0 +1,79 @@ +/* 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, [email protected], 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) +{ + int err, n, x; + + 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 < 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 +