/* 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 xcbc_process.c  XCBC Support, process blocks with XCBC*/#ifdef LTC_XCBC/** Process data through XCBC-MAC  @param xcbc     The XCBC-MAC state  @param in       Input data to process  @param inlen    Length of input in octets  Return CRYPT_OK on success*/int xcbc_process(xcbc_state *xcbc, const unsigned char *in, unsigned long inlen){   int err;#ifdef LTC_FAST   int x;#endif   LTC_ARGCHK(xcbc != NULL);   LTC_ARGCHK(in   != NULL);   /* check structure */   if ((err = cipher_is_valid(xcbc->cipher)) != CRYPT_OK) {      return err;   }   if ((xcbc->blocksize > cipher_descriptor[xcbc->cipher].block_length) || (xcbc->blocksize < 0) ||       (xcbc->buflen > xcbc->blocksize) || (xcbc->buflen < 0)) {      return CRYPT_INVALID_ARG;   }#ifdef LTC_FAST   if (xcbc->buflen == 0) {       while (inlen > (unsigned long)xcbc->blocksize) {           for (x = 0; x < xcbc->blocksize; x += sizeof(LTC_FAST_TYPE)) {              *((LTC_FAST_TYPE*)&(xcbc->IV[x])) ^= *((LTC_FAST_TYPE*)&(in[x]));           }           cipher_descriptor[xcbc->cipher].ecb_encrypt(xcbc->IV, xcbc->IV, &xcbc->key);           in    += xcbc->blocksize;           inlen -= xcbc->blocksize;       }  }#endif   while (inlen) {     if (xcbc->buflen == xcbc->blocksize) {         cipher_descriptor[xcbc->cipher].ecb_encrypt(xcbc->IV, xcbc->IV, &xcbc->key);         xcbc->buflen = 0;     }     xcbc->IV[xcbc->buflen++] ^= *in++;     --inlen;  }  return CRYPT_OK;       }#endif/* $Source: /cvs/libtom/libtomcrypt/src/mac/xcbc/xcbc_process.c,v $ *//* $Revision: 1.9 $ *//* $Date: 2006/11/09 22:43:52 $ */