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/* rsa.h
*
* The RSA publickey algorithm.
*/
/* nettle, low-level cryptographics library
*
* Copyright (C) 2001 Niels Möller
*
* 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_RSA_H_INCLUDED
#define NETTLE_RSA_H_INCLUDED
#include <inttypes.h>
#include <gmp.h>
#include "md5.h"
#include "sha.h"
struct rsa_public_key
{
/* Size of the modulo, in octets. This is also the size of all
* signatures that are created or verified with this key. */
unsigned size;
/* Modulo */
mpz_t n;
/* Public exponent */
mpz_t e;
};
struct rsa_private_key
{
struct rsa_public_key pub;
/* Secret exponent */
mpz_t d;
/* The two factors */
mpz_t p; mpz_t q;
/* d % (p-1), i.e. a e = 1 (mod (p-1)) */
mpz_t a;
/* d % (q-1), i.e. b e = 1 (mod (q-1)) */
mpz_t b;
/* modular inverse of q , i.e. c q = 1 (mod p) */
mpz_t c;
};
/* Signing a message works as follows:
*
* Store the private key in a rsa_private_key struct.
*
* Call rsa_prepare_private_key. This initializes the size attribute
* to the length of a signature.
*
* Initialize a hashing context, by callling
* md5_init
*
* Hash the message by calling
* md5_update
*
* Create the signature by calling
* rsa_md5_sign
*
* The signature is represented as a mpz_t bignum. This call also
* resets the hashing context.
*
* When done with the key and signature, don't forget to call
* mpz_clear.
*/
/* Calls mpz_init to initialize bignum storage. */
void
rsa_init_public_key(struct rsa_public_key *key);
/* Calls mpz_clear to deallocate bignum storage. */
void
rsa_clear_public_key(struct rsa_public_key *key);
int
rsa_prepare_public_key(struct rsa_public_key *key);
/* Calls mpz_init to initialize bignum storage. */
void
rsa_init_private_key(struct rsa_private_key *key);
/* Calls mpz_clear to deallocate bignum storage. */
void
rsa_clear_private_key(struct rsa_private_key *key);
int
rsa_prepare_private_key(struct rsa_private_key *key);
/* PKCS#1 style signatures */
void
rsa_md5_sign(struct rsa_private_key *key,
struct md5_ctx *hash,
mpz_t signature);
int
rsa_md5_verify(struct rsa_public_key *key,
struct md5_ctx *hash,
const mpz_t signature);
void
rsa_sha1_sign(struct rsa_private_key *key,
struct sha1_ctx *hash,
mpz_t signature);
int
rsa_sha1_verify(struct rsa_public_key *key,
struct sha1_ctx *hash,
const mpz_t signature);
/* Compute x, the d:th root of m. Calling it with x == m is allowed. */
void
rsa_compute_root(struct rsa_private_key *key, mpz_t x, const mpz_t m);
#endif /* NETTLE_RSA_H_INCLUDED */
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