dsa.h

/* dsa.h
 *
 * The DSA publickey algorithm.
 */

/* nettle, low-level cryptographics library
 *
 * Copyright (C) 2002 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.
 */
 
#ifndef NETTLE_DSA_H_INCLUDED
#define NETTLE_DSA_H_INCLUDED

#include <inttypes.h>
#include <gmp.h>

#include "sha.h"

/* For nettle_random_func */
#include "nettle-meta.h"

#define DSA_MIN_P_BITS 512
#define DSA_Q_OCTETS 20
#define DSA_Q_BITS 160

struct dsa_public_key
{  
  /* Modulo */
  mpz_t p;

  /* Group order */
  mpz_t q;

  /* Generator */
  mpz_t g;
  
  /* Public value */
  mpz_t y;
};

struct dsa_private_key
{
  /* Unlike an rsa public key, private key operations will need both
   * the private and the public information. */
  mpz_t x;
};

struct dsa_signature
{
  mpz_t r;
  mpz_t s;
};

/* Signing a message works as follows:
 *