/* 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 $ */