view libtomcrypt/src/mac/pmac/pmac_memory_multi.c @ 994:5c5ade336926

Prefer stronger algorithms in algorithm negotiation. Prefer diffie-hellman-group14-sha1 (2048 bit) over diffie-hellman-group1-sha1 (1024 bit). Due to meet-in-the-middle attacks the effective key length of three key 3DES is 112 bits. AES is stronger and faster then 3DES. Prefer to delay the start of compression until after authentication has completed. This avoids exposing compression code to attacks from unauthenticated users. (github pull request #9)
author Fedor Brunner <fedor.brunner@azet.sk>
date Fri, 23 Jan 2015 23:00:25 +0800
parents 0cbe8f6dbf9e
children f849a5ca2efc
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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.com
 */
#include "tomcrypt.h"
#include <stdarg.h>

/** 
   @file pmac_memory_multi.c
   PMAC implementation, process multiple blocks of memory, by Tom St Denis 
*/

#ifdef LTC_PMAC

/**
   PMAC multiple blocks of memory
   @param cipher   The index of the cipher desired
   @param key      The secret key
   @param keylen   The length of the secret key (octets)
   @param out      [out] Destination for the authentication tag
   @param outlen   [in/out] The max size and resulting size of the authentication tag
   @param in       The data you wish to send through PMAC
   @param inlen    The length of data you wish to send through PMAC (octets)
   @param ...      tuples of (data,len) pairs to PMAC, terminated with a (NULL,x) (x=don't care)
   @return CRYPT_OK if successful
*/
int pmac_memory_multi(int cipher, 
                const unsigned char *key, unsigned long  keylen,
                      unsigned char *out, unsigned long *outlen,
                const unsigned char *in,  unsigned long  inlen, ...)
{
   int                  err;
   pmac_state          *pmac;
   va_list              args;
   const unsigned char *curptr;
   unsigned long        curlen;

   LTC_ARGCHK(key    != NULL);
   LTC_ARGCHK(in     != NULL);
   LTC_ARGCHK(out    != NULL);
   LTC_ARGCHK(outlen != NULL);

   /* allocate ram for pmac state */
   pmac = XMALLOC(sizeof(pmac_state));
   if (pmac == NULL) {
      return CRYPT_MEM;
   }
   
   if ((err = pmac_init(pmac, cipher, key, keylen)) != CRYPT_OK) {
      goto LBL_ERR;
   }
   va_start(args, inlen);
   curptr = in; 
   curlen = inlen;
   for (;;) {
      /* process buf */
      if ((err = pmac_process(pmac, curptr, curlen)) != CRYPT_OK) {
         goto LBL_ERR;
      }
      /* step to next */
      curptr = va_arg(args, const unsigned char*);
      if (curptr == NULL) {
         break;
      }
      curlen = va_arg(args, unsigned long);
   }
   if ((err = pmac_done(pmac, out, outlen)) != CRYPT_OK) {
      goto LBL_ERR;
   }
LBL_ERR:
#ifdef LTC_CLEAN_STACK
   zeromem(pmac, sizeof(pmac_state));
#endif
   XFREE(pmac);
   va_end(args);
   return err;   
}

#endif

/* $Source: /cvs/libtom/libtomcrypt/src/mac/pmac/pmac_memory_multi.c,v $ */
/* $Revision: 1.6 $ */
/* $Date: 2006/11/03 00:39:49 $ */