view libtomcrypt/src/pk/katja/katja_export.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"

/**
  @file katja_export.c
  Export Katja PKCS-style keys, Tom St Denis
*/  

#ifdef MKAT

/**
    This will export either an KatjaPublicKey or KatjaPrivateKey
    @param out       [out] Destination of the packet
    @param outlen    [in/out] The max size and resulting size of the packet
    @param type      The type of exported key (PK_PRIVATE or PK_PUBLIC)
    @param key       The Katja key to export
    @return CRYPT_OK if successful
*/    
int katja_export(unsigned char *out, unsigned long *outlen, int type, katja_key *key)
{
   int           err;
   unsigned long zero=0;

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

   /* type valid? */
   if (!(key->type == PK_PRIVATE) && (type == PK_PRIVATE)) {
      return CRYPT_PK_INVALID_TYPE;
   }

   if (type == PK_PRIVATE) {
      /* private key */
      /* output is 
            Version, n, d, p, q, d mod (p-1), d mod (q - 1), 1/q mod p, pq
       */
      if ((err = der_encode_sequence_multi(out, outlen, 
                          LTC_ASN1_SHORT_INTEGER, 1UL, &zero, 
                          LTC_ASN1_INTEGER, 1UL,  key->N, 
                          LTC_ASN1_INTEGER, 1UL,  key->d, 
                          LTC_ASN1_INTEGER, 1UL,  key->p, 
                          LTC_ASN1_INTEGER, 1UL,  key->q, 
                          LTC_ASN1_INTEGER, 1UL,  key->dP,
                          LTC_ASN1_INTEGER, 1UL,  key->dQ, 
                          LTC_ASN1_INTEGER, 1UL,  key->qP, 
                          LTC_ASN1_INTEGER, 1UL,  key->pq, 
                          LTC_ASN1_EOL,     0UL, NULL)) != CRYPT_OK) {
         return err;
      }
 
      /* clear zero and return */
      return CRYPT_OK;
   } else {
      /* public key */
      return der_encode_sequence_multi(out, outlen, 
                                 LTC_ASN1_INTEGER, 1UL, key->N, 
                                 LTC_ASN1_EOL,     0UL, NULL);
   }
}

#endif /* MRSA */

/* $Source: /cvs/libtom/libtomcrypt/src/pk/katja/katja_export.c,v $ */
/* $Revision: 1.2 $ */
/* $Date: 2006/03/31 14:15:35 $ */