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eax_encrypt_authenticate_memory.c
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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, tomstdenis@gmail.com, http://libtom.org
 */

/**
  @file eax_encrypt_authenticate_memory.c
  EAX implementation, encrypt a block of memory, by Tom St Denis
*/
#include "tomcrypt.h"

#ifdef LTC_EAX_MODE

/**
   EAX encrypt and produce an authentication tag
   @param cipher     The index of the cipher desired
   @param key        The secret key to use
   @param keylen     The length of the secret key (octets)
   @param nonce      The session nonce [use once]
   @param noncelen   The length of the nonce
   @param header     The header for the session
   @param headerlen  The length of the header (octets)
   @param pt         The plaintext
   @param ptlen      The length of the plaintext (octets)
   @param ct         [out] The ciphertext
   @param tag        [out] The destination tag
   @param taglen     [in/out] The max size and resulting size of the authentication tag
   @return CRYPT_OK if successful
*/
int eax_encrypt_authenticate_memory(int cipher,
    const unsigned char *key,    unsigned long keylen,
    const unsigned char *nonce,  unsigned long noncelen,
    const unsigned char *header, unsigned long headerlen,
    const unsigned char *pt,     unsigned long ptlen,
          unsigned char *ct,
          unsigned char *tag,    unsigned long *taglen)
{
   int err;
   eax_state *eax;

   LTC_ARGCHK(key    != NULL);
   LTC_ARGCHK(pt     != NULL);
   LTC_ARGCHK(ct     != NULL);
   LTC_ARGCHK(tag    != NULL);
   LTC_ARGCHK(taglen != NULL);

   eax = XMALLOC(sizeof(*eax));

   if ((err = eax_init(eax, cipher, key, keylen, nonce, noncelen, header, headerlen)) != CRYPT_OK) {
      goto LBL_ERR; 
   }

   if ((err = eax_encrypt(eax, pt, ct, ptlen)) != CRYPT_OK) {
      goto LBL_ERR; 
   }
 
   if ((err = eax_done(eax, tag, taglen)) != CRYPT_OK) {
      goto LBL_ERR; 
   }

   err = CRYPT_OK;
LBL_ERR:
#ifdef LTC_CLEAN_STACK
   zeromem(eax, sizeof(*eax));
#endif

   XFREE(eax);

   return err;   
}

#endif

/* $Source: /cvs/libtom/libtomcrypt/src/encauth/eax/eax_encrypt_authenticate_memory.c,v $ */
/* $Revision: 1.6 $ */
/* $Date: 2007/05/12 14:32:35 $ */

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