rsa-compat.c

/* rsa-compat.c
 *
 * The RSA publickey algorithm, RSAREF compatible interface.
 */

/* nettle, low-level cryptographics library
 *
 * Copyright (C) 2001 Niels Mller
 *  
 * The nettle library is free software; you can redistribute it and/or modify
 * it under the terms of the GNU Lesser General Public License as published by
 * the Free Software Foundation; either version 2.1 of the License, or (at your
 * option) any later version.
 * 
 * The nettle library is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
 * or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU Lesser General Public
 * License for more details.
 * 
 * You should have received a copy of the GNU Lesser General Public License
 * along with the nettle library; see the file COPYING.LIB.  If not, write to
 * the Free Software Foundation, Inc., 59 Temple Place - Suite 330, Boston,
 * MA 02111-1307, USA.
 */

#include "rsa-compat.h"

#include "bignum.h"
#include "md5.h"

int
R_SignInit(R_SIGNATURE_CTX *ctx,
           int digestAlgorithm)
{
  if (digestAlgorithm != DA_MD5)
    return RE_DIGEST_ALGORITHM;

  md5_init(&ctx->hash);

  return 0;
}

int
R_SignUpdate(R_SIGNATURE_CTX *ctx,
             const uint8_t *data,
             /* Length is an unsigned char according to rsaref.txt,
              * but that must be a typo. */
             unsigned length)
{
  md5_update(&ctx->hash, length, data);

  return RE_SUCCESS;
}

int
R_SignFinal(R_SIGNATURE_CTX *ctx,
            uint8_t *signature,
            unsigned *length,
            R_RSA_PRIVATE_KEY *key)
{
  struct rsa_private_key k;
  int res;
  
  nettle_mpz_init_set_str_256(k.p,
                              MAX_RSA_MODULUS_LEN, key->prime[0]);
  nettle_mpz_init_set_str_256(k.q,
                              MAX_RSA_MODULUS_LEN, key->prime[1]);
  nettle_mpz_init_set_str_256(k.a,
                              MAX_RSA_MODULUS_LEN, key->primeExponent[0]);
  nettle_mpz_init_set_str_256(k.b,