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_done.c
    PMAC implementation, terminate a session, by Tom St Denis 
  */
  
  #ifdef LTC_PMAC
  
  int pmac_done(pmac_state *state, unsigned char *out, unsigned long *outlen)
  {
     int err, x;
  
     LTC_ARGCHK(state != NULL);
     LTC_ARGCHK(out   != NULL);
     if ((err = cipher_is_valid(state->cipher_idx)) != CRYPT_OK) {
        return err;
     }
  
     if ((state->buflen > (int)sizeof(state->block)) || (state->buflen < 0) ||
         (state->block_len > (int)sizeof(state->block)) || (state->buflen > state->block_len)) {
        return CRYPT_INVALID_ARG;
     }
  
  
     /* handle padding.  If multiple xor in L/x */
  
     if (state->buflen == state->block_len) {
        /* xor Lr against the checksum */
        for (x = 0; x < state->block_len; x++) {
            state->checksum[x] ^= state->block[x] ^ state->Lr[x];
        }
     } else {
        /* otherwise xor message bytes then the 0x80 byte */
        for (x = 0; x < state->buflen; x++) {
            state->checksum[x] ^= state->block[x];
        }
        state->checksum[x] ^= 0x80;
     }
  
     /* encrypt it */
     if ((err = cipher_descriptor[state->cipher_idx].ecb_encrypt(state->checksum, state->checksum, &state->key)) != CRYPT_OK) {
        return err;
     }
     cipher_descriptor[state->cipher_idx].done(&state->key);
  
     /* store it */
     for (x = 0; x < state->block_len && x < (int)*outlen; x++) {
         out[x] = state->checksum[x];
     }
     *outlen = x;
  
  #ifdef LTC_CLEAN_STACK
     zeromem(state, sizeof(*state));
  #endif
     return CRYPT_OK;
  }
  
  #endif
  
  
  /* $Source: /cvs/libtom/libtomcrypt/src/mac/pmac/pmac_done.c,v $ */
  /* $Revision: 1.9 $ */
  /* $Date: 2006/12/28 01:27:23 $ */
  