/* 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 f9_done.c  f9 Support, terminate the state*/#ifdef LTC_F9_MODE/** Terminate the f9-MAC state  @param f9     f9 state to terminate  @param out      [out] Destination for the MAC tag  @param outlen   [in/out] Destination size and final tag size  Return CRYPT_OK on success*/int f9_done(f9_state *f9, unsigned char *out, unsigned long *outlen){   int err, x;   LTC_ARGCHK(f9 != NULL);   LTC_ARGCHK(out  != NULL);   /* check structure */   if ((err = cipher_is_valid(f9->cipher)) != CRYPT_OK) {      return err;   }   if ((f9->blocksize > cipher_descriptor[f9->cipher].block_length) || (f9->blocksize < 0) ||       (f9->buflen > f9->blocksize) || (f9->buflen < 0)) {      return CRYPT_INVALID_ARG;   }   if (f9->buflen != 0) {      /* encrypt */      cipher_descriptor[f9->cipher].ecb_encrypt(f9->IV, f9->IV, &f9->key);      f9->buflen = 0;      for (x = 0; x < f9->blocksize; x++) {         f9->ACC[x] ^= f9->IV[x];      }   }   /* schedule modified key */   if ((err = cipher_descriptor[f9->cipher].setup(f9->akey, f9->keylen, 0, &f9->key)) != CRYPT_OK) {      return err;   }   /* encrypt the ACC */   cipher_descriptor[f9->cipher].ecb_encrypt(f9->ACC, f9->ACC, &f9->key);   cipher_descriptor[f9->cipher].done(&f9->key);   /* extract tag */   for (x = 0; x < f9->blocksize && (unsigned long)x < *outlen; x++) {      out[x] = f9->ACC[x];   }   *outlen = x;  #ifdef LTC_CLEAN_STACK   zeromem(f9, sizeof(*f9));#endif   return CRYPT_OK;}#endif/* $Source: /cvs/libtom/libtomcrypt/src/mac/f9/f9_done.c,v $ *//* $Revision: 1.6 $ *//* $Date: 2006/12/28 01:27:23 $ */