Commit 27ea18ab authored by Niels Möller's avatar Niels Möller

New function dsa_generate_params.

parent bf85a3db
2014-03-27 Niels Möller <nisse@lysator.liu.se>
* dsa-gen-params.c (dsa_generate_params): New file and function,
extracted from DSA key generation.
* dsa-keygen.c (dsa_generate_keypair): Use dsa_generate_params.
2014-03-26 Niels Möller <nisse@lysator.liu.se>
* der2dsa.c (dsa_params_from_der_iterator): Converted to new DSA
......
......@@ -148,7 +148,8 @@ hogweed_SOURCES = sexp.c sexp-format.c \
rsa-encrypt.c rsa-decrypt.c rsa-decrypt-tr.c \
rsa-keygen.c rsa-compat.c rsa-blind.c \
rsa2sexp.c sexp2rsa.c \
dsa.c dsa-sign.c dsa-verify.c dsa-keygen.c dsa-hash.c \
dsa.c dsa-gen-params.c \
dsa-sign.c dsa-verify.c dsa-keygen.c dsa-hash.c \
dsa-sha1-sign.c dsa-sha1-verify.c \
dsa-sha256-sign.c dsa-sha256-verify.c \
dsa2sexp.c sexp2dsa.c \
......
/* dsa-gen-params.c
*
* Generation of DSA parameters
*/
/* nettle, low-level cryptographics library
*
* Copyright (C) 2002, 2013, 2014 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., 51 Franklin Street, Fifth Floor, Boston,
* MA 02111-1301, USA.
*/
#if HAVE_CONFIG_H
# include "config.h"
#endif
#include <assert.h>
#include <stdlib.h>
#include "dsa.h"
#include "bignum.h"
#include "nettle-internal.h"
/* Valid sizes, according to FIPS 186-3 are (1024, 160), (2048, 224),
(2048, 256), (3072, 256). */
int
dsa_generate_params(struct dsa_params *params,
void *random_ctx, nettle_random_func *random,
void *progress_ctx, nettle_progress_func *progress,
unsigned p_bits, unsigned q_bits)
{
mpz_t r;
unsigned p0_bits;
unsigned a;
if (q_bits < 30 || p_bits < q_bits + 30)
return 0;
mpz_init (r);
nettle_random_prime (params->q, q_bits, 0, random_ctx, random,
progress_ctx, progress);
if (q_bits >= (p_bits + 2)/3)
_nettle_generate_pocklington_prime (params->p, r, p_bits, 0,
random_ctx, random,
params->q, NULL, params->q);
else
{
mpz_t p0, p0q;
mpz_init (p0);
mpz_init (p0q);
p0_bits = (p_bits + 3)/2;
nettle_random_prime (p0, p0_bits, 0,
random_ctx, random,
progress_ctx, progress);
if (progress)
progress (progress_ctx, 'q');
/* Generate p = 2 r q p0 + 1, such that 2^{n-1} < p < 2^n. */
mpz_mul (p0q, p0, params->q);
_nettle_generate_pocklington_prime (params->p, r, p_bits, 0,
random_ctx, random,
p0, params->q, p0q);
mpz_mul (r, r, p0);
mpz_clear (p0);
mpz_clear (p0q);
}
if (progress)
progress (progress_ctx, 'p');
for (a = 2; ; a++)
{
mpz_set_ui (params->g, a);
mpz_powm (params->g, params->g, r, params->p);
if (mpz_cmp_ui (params->g, 1) != 0)
break;
}
mpz_clear (r);
if (progress)
progress (progress_ctx, 'g');
return 1;
}
......@@ -5,7 +5,7 @@
/* nettle, low-level cryptographics library
*
* Copyright (C) 2002 Niels Möller
* Copyright (C) 2002, 2014 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
......@@ -36,8 +36,7 @@
/* Valid sizes, according to FIPS 186-3 are (1024, 160), (2048, 224),
(2048, 256), (3072, 256). Currenty, we use only q_bits of 160 or
256. */
(2048, 256), (3072, 256). */
int
dsa_generate_keypair(struct dsa_public_key *pub,
struct dsa_private_key *key,
......@@ -45,9 +44,8 @@ dsa_generate_keypair(struct dsa_public_key *pub,
void *progress_ctx, nettle_progress_func *progress,
unsigned p_bits, unsigned q_bits)
{
mpz_t p0, p0q, r;
unsigned p0_bits;
unsigned a;
struct dsa_params *params;
mpz_t r;
switch (q_bits)
{
......@@ -64,49 +62,16 @@ dsa_generate_keypair(struct dsa_public_key *pub,
return 0;
}
mpz_init (p0);
mpz_init (p0q);
mpz_init (r);
/* NOTE: Depends on identical layout! */
params = (struct dsa_params *) pub;
nettle_random_prime (pub->q, q_bits, 0, random_ctx, random,
progress_ctx, progress);
p0_bits = (p_bits + 3)/2;
nettle_random_prime (p0, p0_bits, 0,
random_ctx, random,
progress_ctx, progress);
if (progress)
progress (progress_ctx, 'q');
if (!dsa_generate_params (params,
random_ctx, random,
progress_ctx, progress,
p_bits, q_bits))
return 0;
/* Generate p = 2 r q p0 + 1, such that 2^{n-1} < p < 2^n.
*
* We select r in the range i + 1 < r <= 2i, with i = floor (2^{n-2} / (p0 q). */
mpz_mul (p0q, p0, pub->q);
_nettle_generate_pocklington_prime (pub->p, r, p_bits, 0,
random_ctx, random,
p0, pub->q, p0q);
if (progress)
progress (progress_ctx, 'p');
mpz_mul (r, r, p0);
for (a = 2; ; a++)
{
mpz_set_ui (pub->g, a);
mpz_powm (pub->g, pub->g, r, pub->p);
if (mpz_cmp_ui (pub->g, 1) != 0)
break;
}
if (progress)
progress (progress_ctx, 'g');
mpz_set(r, pub->q);
mpz_init_set(r, pub->q);
mpz_sub_ui(r, r, 2);
nettle_mpz_random(key->x, random_ctx, random, r);
......@@ -117,8 +82,6 @@ dsa_generate_keypair(struct dsa_public_key *pub,
if (progress)
progress (progress_ctx, '\n');
mpz_clear (p0);
mpz_clear (p0q);
mpz_clear (r);
return 1;
......
......@@ -56,6 +56,7 @@ extern "C" {
#define dsa_sha1_verify_digest nettle_dsa_sha1_verify_digest
#define dsa_sha256_sign_digest nettle_dsa_sha256_sign_digest
#define dsa_sha256_verify_digest nettle_dsa_sha256_verify_digest
#define dsa_generate_params nettle_dsa_generate_params
#define dsa_generate_keypair nettle_dsa_generate_keypair
#define dsa_signature_from_sexp nettle_dsa_signature_from_sexp
#define dsa_keypair_to_sexp nettle_dsa_keypair_to_sexp
......@@ -235,6 +236,12 @@ dsa_sha256_verify_digest(const struct dsa_public_key *key,
/* Key generation */
int
dsa_generate_params(struct dsa_params *params,
void *random_ctx, nettle_random_func *random,
void *progress_ctx, nettle_progress_func *progress,
unsigned p_bits, unsigned q_bits);
int
dsa_generate_keypair(struct dsa_public_key *pub,
struct dsa_private_key *key,
......
Markdown is supported
0% or
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment