text: /* 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://libtom.org
   */
  #include "tomcrypt.h"
  
  /**
     @file pmac_process.c
     PMAC implementation, process data, by Tom St Denis
  */
  
  
  #ifdef LTC_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]));
            }
            if ((err = cipher_descriptor[pmac->cipher_idx].ecb_encrypt(Z, Z, &pmac->key)) != CRYPT_OK) {
               return err;
            }
            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];
            }
            if ((err = cipher_descriptor[pmac->cipher_idx].ecb_encrypt(Z, Z, &pmac->key)) != CRYPT_OK) {
               return err;
             }
            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
  
  /* $Source$ */
  /* $Revision$ */
  /* $Date$ */
  