view ocb_done_decrypt.c @ 50:c61e66431001 libtomcrypt

Merge of the normal Dropbear makefile: - Don't include mpi.o, since it does Bad Things (tm) (wrt LTM) - Don't try to make clean in tests if it doesn't exist (infinite looping makefiles, mmmmm)
author Matt Johnston <matt@ucc.asn.au>
date Sat, 07 Aug 2004 16:33:31 +0000
parents d7da3b1e1540
children 5d99163f7e32
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/* 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, [email protected], http://libtomcrypt.org
 */

/* OCB Implementation by Tom St Denis */
#include "mycrypt.h"

#ifdef OCB_MODE

int ocb_done_decrypt(ocb_state *ocb, 
                     const unsigned char *ct,  unsigned long ctlen,
                           unsigned char *pt, 
                     const unsigned char *tag, unsigned long taglen, int *res)
{
   int err;
   unsigned char tagbuf[MAXBLOCKSIZE];
   unsigned long tagbuflen;

   _ARGCHK(ocb != NULL);
   _ARGCHK(pt  != NULL);
   _ARGCHK(ct  != NULL);
   _ARGCHK(tag != NULL);
   _ARGCHK(res != NULL);

   *res = 0;

   tagbuflen = sizeof(tagbuf);
   if ((err = __ocb_done(ocb, ct, ctlen, pt, tagbuf, &tagbuflen, 1)) != CRYPT_OK) {
      return err;
   }

   if (taglen <= tagbuflen && memcmp(tagbuf, tag, taglen) == 0) {
      *res = 1;
   }

#ifdef CLEAN_STACK
   zeromem(tagbuf, sizeof(tagbuf));
#endif

   return CRYPT_OK;
}

#endif