[thirdparty/openssl.git] / crypto / bn / bn_x931p.c

/* bn_x931p.c */
/* Written by Dr Stephen N Henson (steve@openssl.org) for the OpenSSL
 * project 2005.
 */
/* ====================================================================
 * Copyright (c) 2005 The OpenSSL Project.  All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer. 
 *
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in
 *    the documentation and/or other materials provided with the
 *    distribution.
 *
 * 3. All advertising materials mentioning features or use of this
 *    software must display the following acknowledgment:
 *    "This product includes software developed by the OpenSSL Project
 *    for use in the OpenSSL Toolkit. (http://www.OpenSSL.org/)"
 *
 * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to
 *    endorse or promote products derived from this software without
 *    prior written permission. For written permission, please contact
 *    licensing@OpenSSL.org.
 *
 * 5. Products derived from this software may not be called "OpenSSL"
 *    nor may "OpenSSL" appear in their names without prior written
 *    permission of the OpenSSL Project.
 *
 * 6. Redistributions of any form whatsoever must retain the following
 *    acknowledgment:
 *    "This product includes software developed by the OpenSSL Project
 *    for use in the OpenSSL Toolkit (http://www.OpenSSL.org/)"
 *
 * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY
 * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE OpenSSL PROJECT OR
 * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
 * OF THE POSSIBILITY OF SUCH DAMAGE.
 * ====================================================================
 *
 * This product includes cryptographic software written by Eric Young
 * (eay@cryptsoft.com).  This product includes software written by Tim
 * Hudson (tjh@cryptsoft.com).
 *
 */

#include <stdio.h>
#include <openssl/bn.h>
#include "bn_lcl.h"

/* X9.31 routines for prime derivation */

/* X9.31 prime derivation. This is used to generate the primes pi
 * (p1, p2, q1, q2) from a parameter Xpi by checking successive odd
 * integers.
 */

static int bn_x931_derive_pi(BIGNUM *pi, const BIGNUM *Xpi, BN_CTX *ctx,
			BN_GENCB *cb)
	{
	int i = 0;
	if (!BN_copy(pi, Xpi))
		return 0;
	if (!BN_is_odd(pi) && !BN_add_word(pi, 1))
		return 0;
	for(;;)
		{
		i++;
		BN_GENCB_call(cb, 0, i);
		/* NB 27 MR is specificed in X9.31 */
		if (BN_is_prime_fasttest_ex(pi, 27, ctx, 1, cb))
			break;
		if (!BN_add_word(pi, 2))
			return 0;
		}
	BN_GENCB_call(cb, 2, i);
	return 1;
	}

/* This is the main X9.31 prime derivation function. From parameters
 * Xp1, Xp2 and Xp derive the prime p. If the parameters p1 or p2 are
 * not NULL they will be returned too: this is needed for testing.
 */

int BN_X931_derive_prime_ex(BIGNUM *p, BIGNUM *p1, BIGNUM *p2,
			const BIGNUM *Xp, const BIGNUM *Xp1, const BIGNUM *Xp2,
			const BIGNUM *e, BN_CTX *ctx, BN_GENCB *cb)
	{
	int ret = 0;

	BIGNUM *t, *p1p2, *pm1;

	/* Only even e supported */
	if (!BN_is_odd(e))
		return 0;

	BN_CTX_start(ctx);
	if (!p1)
		p1 = BN_CTX_get(ctx);

	if (!p2)
		p2 = BN_CTX_get(ctx);

	t = BN_CTX_get(ctx);

	p1p2 = BN_CTX_get(ctx);

	pm1 = BN_CTX_get(ctx);

	if (!bn_x931_derive_pi(p1, Xp1, ctx, cb))
		goto err;

	if (!bn_x931_derive_pi(p2, Xp2, ctx, cb))
		goto err;

	if (!BN_mul(p1p2, p1, p2, ctx))
		goto err;

	/* First set p to value of Rp */

	if (!BN_mod_inverse(p, p2, p1, ctx))
		goto err;

	if (!BN_mul(p, p, p2, ctx))
		goto err;

	if (!BN_mod_inverse(t, p1, p2, ctx))
		goto err;

	if (!BN_mul(t, t, p1, ctx))
		goto err;

	if (!BN_sub(p, p, t))
		goto err;

	if (p->neg && !BN_add(p, p, p1p2))
		goto err;

	/* p now equals Rp */

	if (!BN_mod_sub(p, p, Xp, p1p2, ctx))
		goto err;

	if (!BN_add(p, p, Xp))
		goto err;

	/* p now equals Yp0 */

	for (;;)
		{
		int i = 1;
		BN_GENCB_call(cb, 0, i++);
		if (!BN_copy(pm1, p))
			goto err;
		if (!BN_sub_word(pm1, 1))
			goto err;
		if (!BN_gcd(t, pm1, e, ctx))
			goto err;
		if (BN_is_one(t)
		/* X9.31 specifies 8 MR and 1 Lucas test or any prime test
		 * offering similar or better guarantees 50 MR is considerably 
		 * better.
		 */
			&& BN_is_prime_fasttest_ex(p, 50, ctx, 1, cb))
			break;
		if (!BN_add(p, p, p1p2))
			goto err;
		}

	BN_GENCB_call(cb, 3, 0);

	ret = 1;

	err:

	BN_CTX_end(ctx);

	return ret;
	}

/* Generate pair of parameters Xp, Xq for X9.31 prime generation.
 * Note: nbits parameter is sum of number of bits in both.
 */

int BN_X931_generate_Xpq(BIGNUM *Xp, BIGNUM *Xq, int nbits, BN_CTX *ctx)
	{
	BIGNUM *t;
	int i;
	/* Number of bits for each prime is of the form
	 * 512+128s for s = 0, 1, ...
	 */
	if ((nbits < 1024) || (nbits & 0xff))
		return 0;
	nbits >>= 1;
	/* The random value Xp must be between sqrt(2) * 2^(nbits-1) and
	 * 2^nbits - 1. By setting the top two bits we ensure that the lower
	 * bound is exceeded.
	 */
	if (!BN_rand(Xp, nbits, 1, 0))
		return 0;

	BN_CTX_start(ctx);
	t = BN_CTX_get(ctx);

	for (i = 0; i < 1000; i++)
		{
		if (!BN_rand(Xq, nbits, 1, 0))
			return 0;
		/* Check that |Xp - Xq| > 2^(nbits - 100) */
		BN_sub(t, Xp, Xq);
		if (BN_num_bits(t) > (nbits - 100))
			break;
		}

	BN_CTX_end(ctx);

	if (i < 1000)
		return 1;

	return 0;

	}

/* Generate primes using X9.31 algorithm. Of the values p, p1, p2, Xp1
 * and Xp2 only 'p' needs to be non-NULL. If any of the others are not NULL
 * the relevant parameter will be stored in it.
 *
 * Due to the fact that |Xp - Xq| > 2^(nbits - 100) must be satisfied Xp and Xq
 * are generated using the previous function and supplied as input.
 */

int BN_X931_generate_prime_ex(BIGNUM *p, BIGNUM *p1, BIGNUM *p2,
			BIGNUM *Xp1, BIGNUM *Xp2,
			const BIGNUM *Xp,
			const BIGNUM *e, BN_CTX *ctx,
			BN_GENCB *cb)
	{
	int ret = 0;

	BN_CTX_start(ctx);
	if (!Xp1)
		Xp1 = BN_CTX_get(ctx);
	if (!Xp2)
		Xp2 = BN_CTX_get(ctx);

	if (!BN_rand(Xp1, 101, 0, 0))
		goto error;
	if (!BN_rand(Xp2, 101, 0, 0))
		goto error;
	if (!BN_X931_derive_prime_ex(p, p1, p2, Xp, Xp1, Xp2, e, ctx, cb))
		goto error;

	ret = 1;

	error:
	BN_CTX_end(ctx);

	return ret;

	}
Commit	Line	Data
7b1a0451 DSH	1	/* bn_x931p.c */
	2	/* Written by Dr Stephen N Henson (steve@openssl.org) for the OpenSSL
	3	* project 2005.
	4	*/
	5	/* ====================================================================
	6	* Copyright (c) 2005 The OpenSSL Project. All rights reserved.
	7	*
	8	* Redistribution and use in source and binary forms, with or without
	9	* modification, are permitted provided that the following conditions
	10	* are met:
	11	*
	12	* 1. Redistributions of source code must retain the above copyright
	13	* notice, this list of conditions and the following disclaimer.
	14	*
	15	* 2. Redistributions in binary form must reproduce the above copyright
	16	* notice, this list of conditions and the following disclaimer in
	17	* the documentation and/or other materials provided with the
	18	* distribution.
	19	*
	20	* 3. All advertising materials mentioning features or use of this
	21	* software must display the following acknowledgment:
	22	* "This product includes software developed by the OpenSSL Project
	23	* for use in the OpenSSL Toolkit. (http://www.OpenSSL.org/)"
	24	*
	25	* 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to
	26	* endorse or promote products derived from this software without
	27	* prior written permission. For written permission, please contact
	28	* licensing@OpenSSL.org.
	29	*
	30	* 5. Products derived from this software may not be called "OpenSSL"
	31	* nor may "OpenSSL" appear in their names without prior written
	32	* permission of the OpenSSL Project.
	33	*
	34	* 6. Redistributions of any form whatsoever must retain the following
	35	* acknowledgment:
	36	* "This product includes software developed by the OpenSSL Project
	37	* for use in the OpenSSL Toolkit (http://www.OpenSSL.org/)"
	38	*
	39	* THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY
	40	* EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
	41	* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
	42	* PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE OpenSSL PROJECT OR
	43	* ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
	44	* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
	45	* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
	46	* LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
	47	* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
	48	* STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
	49	* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
	50	* OF THE POSSIBILITY OF SUCH DAMAGE.
	51	* ====================================================================
	52	*
	53	* This product includes cryptographic software written by Eric Young
	54	* (eay@cryptsoft.com). This product includes software written by Tim
	55	* Hudson (tjh@cryptsoft.com).
	56	*
	57	*/
	58
	59	#include <stdio.h>
	60	#include <openssl/bn.h>
85bcf27c	61	#include "bn_lcl.h"
7b1a0451 DSH	62
	63	/* X9.31 routines for prime derivation */
	64
	65	/* X9.31 prime derivation. This is used to generate the primes pi
	66	* (p1, p2, q1, q2) from a parameter Xpi by checking successive odd
	67	* integers.
	68	*/
	69
	70	static int bn_x931_derive_pi(BIGNUM pi, const BIGNUM Xpi, BN_CTX *ctx,
	71	BN_GENCB *cb)
	72	{
	73	int i = 0;
	74	if (!BN_copy(pi, Xpi))
	75	return 0;
	76	if (!BN_is_odd(pi) && !BN_add_word(pi, 1))
	77	return 0;
	78	for(;;)
	79	{
	80	i++;
	81	BN_GENCB_call(cb, 0, i);
	82	/* NB 27 MR is specificed in X9.31 */
	83	if (BN_is_prime_fasttest_ex(pi, 27, ctx, 1, cb))
	84	break;
	85	if (!BN_add_word(pi, 2))
	86	return 0;
	87	}
	88	BN_GENCB_call(cb, 2, i);
	89	return 1;
	90	}
	91
	92	/* This is the main X9.31 prime derivation function. From parameters
	93	* Xp1, Xp2 and Xp derive the prime p. If the parameters p1 or p2 are
	94	* not NULL they will be returned too: this is needed for testing.
	95	*/
	96
	97	int BN_X931_derive_prime_ex(BIGNUM p, BIGNUM p1, BIGNUM *p2,
	98	const BIGNUM Xp, const BIGNUM Xp1, const BIGNUM *Xp2,
	99	const BIGNUM e, BN_CTX ctx, BN_GENCB *cb)
	100	{
	101	int ret = 0;
	102
	103	BIGNUM t, p1p2, *pm1;
	104
	105	/* Only even e supported */
	106	if (!BN_is_odd(e))
	107	return 0;
	108
	109	BN_CTX_start(ctx);
	110	if (!p1)
	111	p1 = BN_CTX_get(ctx);
	112
	113	if (!p2)
	114	p2 = BN_CTX_get(ctx);
	115
	116	t = BN_CTX_get(ctx);
	117
	118	p1p2 = BN_CTX_get(ctx);
	119
	120	pm1 = BN_CTX_get(ctx);
	121
	122	if (!bn_x931_derive_pi(p1, Xp1, ctx, cb))
	123	goto err;
	124
	125	if (!bn_x931_derive_pi(p2, Xp2, ctx, cb))
126	goto err;
127
128	if (!BN_mul(p1p2, p1, p2, ctx))
129	goto err;
130
131	/* First set p to value of Rp */
132
133	if (!BN_mod_inverse(p, p2, p1, ctx))
134	goto err;
135
136	if (!BN_mul(p, p, p2, ctx))
137	goto err;
138
139	if (!BN_mod_inverse(t, p1, p2, ctx))
140	goto err;
141
142	if (!BN_mul(t, t, p1, ctx))
143	goto err;
144
145	if (!BN_sub(p, p, t))
146	goto err;
147
148	if (p->neg && !BN_add(p, p, p1p2))
149	goto err;
150
151	/* p now equals Rp */
152
153	if (!BN_mod_sub(p, p, Xp, p1p2, ctx))
154	goto err;
155
156	if (!BN_add(p, p, Xp))
157	goto err;
158
159	/* p now equals Yp0 */
160
161	for (;;)
162	{
163	int i = 1;
164	BN_GENCB_call(cb, 0, i++);
165	if (!BN_copy(pm1, p))
166	goto err;
167	if (!BN_sub_word(pm1, 1))
168	goto err;
169	if (!BN_gcd(t, pm1, e, ctx))
170	goto err;
171	if (BN_is_one(t)
172	/* X9.31 specifies 8 MR and 1 Lucas test or any prime test
173	* offering similar or better guarantees 50 MR is considerably
174	* better.
175	*/
176	&& BN_is_prime_fasttest_ex(p, 50, ctx, 1, cb))
177	break;
178	if (!BN_add(p, p, p1p2))
179	goto err;
180	}
181
182	BN_GENCB_call(cb, 3, 0);
183
184	ret = 1;
185
186	err:
187
188	BN_CTX_end(ctx);
189
190	return ret;
191	}
192
1afd7fa9 MO	193	/* Generate pair of parameters Xp, Xq for X9.31 prime generation.
1afd7fa9 MO	194	* Note: nbits parameter is sum of number of bits in both.
7b1a0451 DSH	195	*/
	196
	197	int BN_X931_generate_Xpq(BIGNUM Xp, BIGNUM Xq, int nbits, BN_CTX *ctx)
	198	{
	199	BIGNUM *t;
	200	int i;
	201	/* Number of bits for each prime is of the form
	202	* 512+128s for s = 0, 1, ...
	203	*/
	204	if ((nbits < 1024) \|\| (nbits & 0xff))
	205	return 0;
	206	nbits >>= 1;
	207	/* The random value Xp must be between sqrt(2) * 2^(nbits-1) and
	208	* 2^nbits - 1. By setting the top two bits we ensure that the lower
	209	* bound is exceeded.
	210	*/
	211	if (!BN_rand(Xp, nbits, 1, 0))
	212	return 0;
	213
	214	BN_CTX_start(ctx);
	215	t = BN_CTX_get(ctx);
	216
	217	for (i = 0; i < 1000; i++)
	218	{
	219	if (!BN_rand(Xq, nbits, 1, 0))
	220	return 0;
	221	/* Check that \|Xp - Xq\| > 2^(nbits - 100) */
	222	BN_sub(t, Xp, Xq);
	223	if (BN_num_bits(t) > (nbits - 100))
	224	break;
	225	}
	226
	227	BN_CTX_end(ctx);
	228
	229	if (i < 1000)
	230	return 1;
	231
	232	return 0;
	233
	234	}
	235
	236	/* Generate primes using X9.31 algorithm. Of the values p, p1, p2, Xp1
	237	* and Xp2 only 'p' needs to be non-NULL. If any of the others are not NULL
	238	* the relevant parameter will be stored in it.
	239	*
	240	* Due to the fact that \|Xp - Xq\| > 2^(nbits - 100) must be satisfied Xp and Xq
	241	* are generated using the previous function and supplied as input.
	242	*/
	243
	244	int BN_X931_generate_prime_ex(BIGNUM p, BIGNUM p1, BIGNUM *p2,
	245	BIGNUM Xp1, BIGNUM Xp2,
	246	const BIGNUM *Xp,
	247	const BIGNUM e, BN_CTX ctx,
	248	BN_GENCB *cb)
	249	{
	250	int ret = 0;
	251
	252	BN_CTX_start(ctx);
	253	if (!Xp1)
	254	Xp1 = BN_CTX_get(ctx);
	255	if (!Xp2)
	256	Xp2 = BN_CTX_get(ctx);
	257
	258	if (!BN_rand(Xp1, 101, 0, 0))
259	goto error;
260	if (!BN_rand(Xp2, 101, 0, 0))
261	goto error;
262	if (!BN_X931_derive_prime_ex(p, p1, p2, Xp, Xp1, Xp2, e, ctx, cb))
263	goto error;
264
265	ret = 1;
266
267	error:
268	BN_CTX_end(ctx);
269
270	return ret;
271
272	}
273