Newer
Older
/* 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 <gmp.h>
#include "nettle-types.h"
#include "sha.h"
/* For nettle_random_func */
#include "nettle-meta.h"
/* Name mangling */
#define dsa_public_key_init nettle_dsa_public_key_init
#define dsa_public_key_clear nettle_dsa_public_key_clear
#define dsa_private_key_init nettle_dsa_private_key_init
#define dsa_private_key_clear nettle_dsa_private_key_clear
#define dsa_signature_init nettle_dsa_signature_init
#define dsa_signature_clear nettle_dsa_signature_clear
#define dsa_sign nettle_dsa_sign
#define dsa_verify nettle_dsa_verify
#define dsa_sign_digest nettle_dsa_sign_digest
#define dsa_verify_digest nettle_dsa_verify_digest
#define dsa_generate_keypair nettle_dsa_generate_keypair
#define dsa_signature_from_sexp nettle_dsa_signature_from_sexp
#define dsa_keypair_from_sexp_alist nettle_dsa_keypair_from_sexp_alist
#define dsa_keypair_from_sexp nettle_dsa_keypair_from_sexp
#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:
*
* Store the private key in a dsa_private_key struct.
*
* Initialize a hashing context, by callling
* sha1_init
*
* Hash the message by calling
* sha1_update
*
* Create the signature by calling
* dsa_sign
*
* The signature is represented as a struct dsa_signature. This call also
* resets the hashing context.
*
* When done with the key and signature, don't forget to call
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
*/
/* Calls mpz_init to initialize bignum storage. */
void
dsa_public_key_init(struct dsa_public_key *key);
/* Calls mpz_clear to deallocate bignum storage. */
void
dsa_public_key_clear(struct dsa_public_key *key);
/* Calls mpz_init to initialize bignum storage. */
void
dsa_private_key_init(struct dsa_private_key *key);
/* Calls mpz_clear to deallocate bignum storage. */
void
dsa_private_key_clear(struct dsa_private_key *key);
/* Calls mpz_init to initialize bignum storage. */
void
dsa_signature_init(struct dsa_signature *signature);
/* Calls mpz_clear to deallocate bignum storage. */
void
dsa_signature_clear(struct dsa_signature *signature);
void
dsa_sign(const struct dsa_public_key *pub,
const struct dsa_private_key *key,
void *random_ctx, nettle_random_func random,
struct sha1_ctx *hash,
struct dsa_signature *signature);
int
dsa_verify(const struct dsa_public_key *key,
struct sha1_ctx *hash,
const struct dsa_signature *signature);
void
dsa_sign_digest(const struct dsa_public_key *pub,
const struct dsa_private_key *key,
void *random_ctx, nettle_random_func random,
const uint8_t *digest,
struct dsa_signature *signature);
int
dsa_verify_digest(const struct dsa_public_key *key,
const uint8_t *digest,
const struct dsa_signature *signature);
/* Key generation */
int
dsa_generate_keypair(struct dsa_public_key *pub,
struct dsa_private_key *key,
void *random_ctx, nettle_random_func random,
void *progress_ctx, nettle_progress_func progress,
/* Size of key, in bits.
* Use size = 512 + 64 * l for the official
* NIS key sizes. */
unsigned bits);
struct sexp_iterator;
int
dsa_signature_from_sexp(struct dsa_signature *rs,
struct sexp_iterator *i);
int
dsa_keypair_from_sexp_alist(struct dsa_public_key *pub,
struct dsa_private_key *priv,
unsigned limit,
struct sexp_iterator *i);
/* If PRIV is NULL, expect a public-key expression. If PUB is NULL,
* expect a private key expression and ignore the parts not needed for
* the public key. */
/* Keys must be initialized before calling this function, as usual. */
int
dsa_keypair_from_sexp(struct dsa_public_key *pub,
struct dsa_private_key *priv,
unsigned limit,
unsigned length, const uint8_t *expr);