[gssapi-openssh.git] / openssh / dh.c

/* $OpenBSD: dh.c,v 1.47 2008/06/26 09:19:39 djm Exp $ */
/*
 * Copyright (c) 2000 Niels Provos.  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.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS 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 AUTHOR 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.
 */

#include "includes.h"

#include <sys/param.h>

#include <openssl/bn.h>
#include <openssl/dh.h>

#include <stdarg.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#include "dh.h"
#include "pathnames.h"
#include "log.h"
#include "misc.h"

static int
parse_prime(int linenum, char *line, struct dhgroup *dhg)
{
	char *cp, *arg;
	char *strsize, *gen, *prime;
	const char *errstr = NULL;
	long long n;

	cp = line;
	if ((arg = strdelim(&cp)) == NULL)
		return 0;
	/* Ignore leading whitespace */
	if (*arg == '\0')
		arg = strdelim(&cp);
	if (!arg || !*arg || *arg == '#')
		return 0;

	/* time */
	if (cp == NULL || *arg == '\0')
		goto fail;
	arg = strsep(&cp, " "); /* type */
	if (cp == NULL || *arg == '\0')
		goto fail;
	/* Ensure this is a safe prime */
	n = strtonum(arg, 0, 5, &errstr);
	if (errstr != NULL || n != MODULI_TYPE_SAFE)
		goto fail;
	arg = strsep(&cp, " "); /* tests */
	if (cp == NULL || *arg == '\0')
		goto fail;
	/* Ensure prime has been tested and is not composite */
	n = strtonum(arg, 0, 0x1f, &errstr);
	if (errstr != NULL ||
	    (n & MODULI_TESTS_COMPOSITE) || !(n & ~MODULI_TESTS_COMPOSITE))
		goto fail;
	arg = strsep(&cp, " "); /* tries */
	if (cp == NULL || *arg == '\0')
		goto fail;
	n = strtonum(arg, 0, 1<<30, &errstr);
	if (errstr != NULL || n == 0)
		goto fail;
	strsize = strsep(&cp, " "); /* size */
	if (cp == NULL || *strsize == '\0' ||
	    (dhg->size = (u_int)strtonum(strsize, 0, 64*1024, &errstr)) == 0 ||
	    errstr)
		goto fail;
	/* The whole group is one bit larger */
	dhg->size++;
	gen = strsep(&cp, " "); /* gen */
	if (cp == NULL || *gen == '\0')
		goto fail;
	prime = strsep(&cp, " "); /* prime */
	if (cp != NULL || *prime == '\0')
		goto fail;

	if ((dhg->g = BN_new()) == NULL)
		fatal("parse_prime: BN_new failed");
	if ((dhg->p = BN_new()) == NULL)
		fatal("parse_prime: BN_new failed");
	if (BN_hex2bn(&dhg->g, gen) == 0)
		goto failclean;

	if (BN_hex2bn(&dhg->p, prime) == 0)
		goto failclean;

	if (BN_num_bits(dhg->p) != dhg->size)
		goto failclean;

	if (BN_is_zero(dhg->g) || BN_is_one(dhg->g))
		goto failclean;

	return (1);

 failclean:
	BN_clear_free(dhg->g);
	BN_clear_free(dhg->p);
 fail:
	error("Bad prime description in line %d", linenum);
	return (0);
}

DH *
choose_dh(int min, int wantbits, int max)
{
	FILE *f;
	char line[4096];
	int best, bestcount, which;
	int linenum;
	struct dhgroup dhg;

	if ((f = fopen(_PATH_DH_MODULI, "r")) == NULL &&
	    (f = fopen(_PATH_DH_PRIMES, "r")) == NULL) {
		logit("WARNING: %s does not exist, using fixed modulus",
		    _PATH_DH_MODULI);
		return (dh_new_group14());
	}

	linenum = 0;
	best = bestcount = 0;
	while (fgets(line, sizeof(line), f)) {
		linenum++;
		if (!parse_prime(linenum, line, &dhg))
			continue;
		BN_clear_free(dhg.g);
		BN_clear_free(dhg.p);

		if (dhg.size > max || dhg.size < min)
			continue;

		if ((dhg.size > wantbits && dhg.size < best) ||
		    (dhg.size > best && best < wantbits)) {
			best = dhg.size;
			bestcount = 0;
		}
		if (dhg.size == best)
			bestcount++;
	}
	rewind(f);

	if (bestcount == 0) {
		fclose(f);
		logit("WARNING: no suitable primes in %s", _PATH_DH_PRIMES);
		return (dh_new_group14());
	}

	linenum = 0;
	which = arc4random_uniform(bestcount);
	while (fgets(line, sizeof(line), f)) {
		if (!parse_prime(linenum, line, &dhg))
			continue;
		if ((dhg.size > max || dhg.size < min) ||
		    dhg.size != best ||
		    linenum++ != which) {
			BN_clear_free(dhg.g);
			BN_clear_free(dhg.p);
			continue;
		}
		break;
	}
	fclose(f);
	if (linenum != which+1)
		fatal("WARNING: line %d disappeared in %s, giving up",
		    which, _PATH_DH_PRIMES);

	return (dh_new_group(dhg.g, dhg.p));
}

/* diffie-hellman-groupN-sha1 */

int
dh_pub_is_valid(DH *dh, BIGNUM *dh_pub)
{
	int i;
	int n = BN_num_bits(dh_pub);
	int bits_set = 0;
	BIGNUM *tmp;

	if (dh_pub->neg) {
		logit("invalid public DH value: negative");
		return 0;
	}
	if (BN_cmp(dh_pub, BN_value_one()) != 1) {	/* pub_exp <= 1 */
		logit("invalid public DH value: <= 1");
		return 0;
	}

	if ((tmp = BN_new()) == NULL) {
		error("%s: BN_new failed", __func__);
		return 0;
	}
	if (!BN_sub(tmp, dh->p, BN_value_one()) ||
	    BN_cmp(dh_pub, tmp) != -1) {		/* pub_exp > p-2 */
		BN_clear_free(tmp);
		logit("invalid public DH value: >= p-1");
		return 0;
	}
	BN_clear_free(tmp);

	for (i = 0; i <= n; i++)
		if (BN_is_bit_set(dh_pub, i))
			bits_set++;
	debug2("bits set: %d/%d", bits_set, BN_num_bits(dh->p));

	/* if g==2 and bits_set==1 then computing log_g(dh_pub) is trivial */
	if (bits_set > 1)
		return 1;

	logit("invalid public DH value (%d/%d)", bits_set, BN_num_bits(dh->p));
	return 0;
}

void
dh_gen_key(DH *dh, int need)
{
	int i, bits_set, tries = 0;

	if (dh->p == NULL)
		fatal("dh_gen_key: dh->p == NULL");
	if (need > INT_MAX / 2 || 2 * need >= BN_num_bits(dh->p))
		fatal("dh_gen_key: group too small: %d (2*need %d)",
		    BN_num_bits(dh->p), 2*need);
	do {
		if (dh->priv_key != NULL)
			BN_clear_free(dh->priv_key);
		if ((dh->priv_key = BN_new()) == NULL)
			fatal("dh_gen_key: BN_new failed");
		/* generate a 2*need bits random private exponent */
		if (!BN_rand(dh->priv_key, 2*need, 0, 0))
			fatal("dh_gen_key: BN_rand failed");
		if (DH_generate_key(dh) == 0)
			fatal("DH_generate_key");
		for (i = 0, bits_set = 0; i <= BN_num_bits(dh->priv_key); i++)
			if (BN_is_bit_set(dh->priv_key, i))
				bits_set++;
		debug2("dh_gen_key: priv key bits set: %d/%d",
		    bits_set, BN_num_bits(dh->priv_key));
		if (tries++ > 10)
			fatal("dh_gen_key: too many bad keys: giving up");
	} while (!dh_pub_is_valid(dh, dh->pub_key));
}

DH *
dh_new_group_asc(const char *gen, const char *modulus)
{
	DH *dh;

	if ((dh = DH_new()) == NULL)
		fatal("dh_new_group_asc: DH_new");

	if (BN_hex2bn(&dh->p, modulus) == 0)
		fatal("BN_hex2bn p");
	if (BN_hex2bn(&dh->g, gen) == 0)
		fatal("BN_hex2bn g");

	return (dh);
}

/*
 * This just returns the group, we still need to generate the exchange
 * value.
 */

DH *
dh_new_group(BIGNUM *gen, BIGNUM *modulus)
{
	DH *dh;

	if ((dh = DH_new()) == NULL)
		fatal("dh_new_group: DH_new");
	dh->p = modulus;
	dh->g = gen;

	return (dh);
}

DH *
dh_new_group1(void)
{
	static char *gen = "2", *group1 =
	    "FFFFFFFF" "FFFFFFFF" "C90FDAA2" "2168C234" "C4C6628B" "80DC1CD1"
	    "29024E08" "8A67CC74" "020BBEA6" "3B139B22" "514A0879" "8E3404DD"
	    "EF9519B3" "CD3A431B" "302B0A6D" "F25F1437" "4FE1356D" "6D51C245"
	    "E485B576" "625E7EC6" "F44C42E9" "A637ED6B" "0BFF5CB6" "F406B7ED"
	    "EE386BFB" "5A899FA5" "AE9F2411" "7C4B1FE6" "49286651" "ECE65381"
	    "FFFFFFFF" "FFFFFFFF";

	return (dh_new_group_asc(gen, group1));
}

DH *
dh_new_group14(void)
{
	static char *gen = "2", *group14 =
	    "FFFFFFFF" "FFFFFFFF" "C90FDAA2" "2168C234" "C4C6628B" "80DC1CD1"
	    "29024E08" "8A67CC74" "020BBEA6" "3B139B22" "514A0879" "8E3404DD"
	    "EF9519B3" "CD3A431B" "302B0A6D" "F25F1437" "4FE1356D" "6D51C245"
	    "E485B576" "625E7EC6" "F44C42E9" "A637ED6B" "0BFF5CB6" "F406B7ED"
	    "EE386BFB" "5A899FA5" "AE9F2411" "7C4B1FE6" "49286651" "ECE45B3D"
	    "C2007CB8" "A163BF05" "98DA4836" "1C55D39A" "69163FA8" "FD24CF5F"
	    "83655D23" "DCA3AD96" "1C62F356" "208552BB" "9ED52907" "7096966D"
	    "670C354E" "4ABC9804" "F1746C08" "CA18217C" "32905E46" "2E36CE3B"
	    "E39E772C" "180E8603" "9B2783A2" "EC07A28F" "B5C55DF0" "6F4C52C9"
	    "DE2BCBF6" "95581718" "3995497C" "EA956AE5" "15D22618" "98FA0510"
	    "15728E5A" "8AACAA68" "FFFFFFFF" "FFFFFFFF";

	return (dh_new_group_asc(gen, group14));
}

/*
 * Estimates the group order for a Diffie-Hellman group that has an
 * attack complexity approximately the same as O(2**bits).  Estimate
 * with:  O(exp(1.9223 * (ln q)^(1/3) (ln ln q)^(2/3)))
 */

int
dh_estimate(int bits)
{

	if (bits <= 128)
		return (1024);	/* O(2**86) */
	if (bits <= 192)
		return (2048);	/* O(2**116) */
	return (4096);		/* O(2**156) */
}
Commit	Line	Data
6f25cbdd	1	/* $OpenBSD: dh.c,v 1.47 2008/06/26 09:19:39 djm Exp $ */
3c0ef626	2	/*
	3	* Copyright (c) 2000 Niels Provos. All rights reserved.
	4	*
	5	* Redistribution and use in source and binary forms, with or without
	6	* modification, are permitted provided that the following conditions
	7	* are met:
	8	* 1. Redistributions of source code must retain the above copyright
	9	* notice, this list of conditions and the following disclaimer.
	10	* 2. Redistributions in binary form must reproduce the above copyright
	11	* notice, this list of conditions and the following disclaimer in the
	12	* documentation and/or other materials provided with the distribution.
	13	*
	14	* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
	15	* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
	16	* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
	17	* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
	18	* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
	19	* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
	20	* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
	21	* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
	22	* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
	23	* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
	24	*/
	25
	26	#include "includes.h"
3c0ef626	27
2e437378	28	#include <sys/param.h>
3c0ef626	29
	30	#include <openssl/bn.h>
	31	#include <openssl/dh.h>
3c0ef626	32
2e437378	33	#include <stdarg.h>
	34	#include <stdio.h>
	35	#include <stdlib.h>
	36	#include <string.h>
	37
3c0ef626	38	#include "dh.h"
	39	#include "pathnames.h"
	40	#include "log.h"
	41	#include "misc.h"
	42
	43	static int
	44	parse_prime(int linenum, char line, struct dhgroup dhg)
	45	{
	46	char cp, arg;
	47	char strsize, gen, *prime;
2e437378	48	const char *errstr = NULL;
6f25cbdd	49	long long n;
3c0ef626	50
3c0ef626	51	cp = line;
2e437378	52	if ((arg = strdelim(&cp)) == NULL)
2e437378	53	return 0;
3c0ef626	54	/* Ignore leading whitespace */
	55	if (*arg == '\0')
	56	arg = strdelim(&cp);
e54b3d7c	57	if (!arg \|\| !arg \|\| arg == '#')
3c0ef626	58	return 0;
	59
	60	/* time */
	61	if (cp == NULL \|\| *arg == '\0')
	62	goto fail;
	63	arg = strsep(&cp, " "); /* type */
	64	if (cp == NULL \|\| *arg == '\0')
	65	goto fail;
6f25cbdd	66	/* Ensure this is a safe prime */
	67	n = strtonum(arg, 0, 5, &errstr);
	68	if (errstr != NULL \|\| n != MODULI_TYPE_SAFE)
	69	goto fail;
3c0ef626	70	arg = strsep(&cp, " "); /* tests */
	71	if (cp == NULL \|\| *arg == '\0')
	72	goto fail;
6f25cbdd	73	/* Ensure prime has been tested and is not composite */
	74	n = strtonum(arg, 0, 0x1f, &errstr);
	75	if (errstr != NULL \|\|
	76	(n & MODULI_TESTS_COMPOSITE) \|\| !(n & ~MODULI_TESTS_COMPOSITE))
	77	goto fail;
3c0ef626	78	arg = strsep(&cp, " "); /* tries */
	79	if (cp == NULL \|\| *arg == '\0')
	80	goto fail;
6f25cbdd	81	n = strtonum(arg, 0, 1<<30, &errstr);
	82	if (errstr != NULL \|\| n == 0)
	83	goto fail;
3c0ef626	84	strsize = strsep(&cp, " "); /* size */
3c0ef626	85	if (cp == NULL \|\| *strsize == '\0' \|\|
2e437378	86	(dhg->size = (u_int)strtonum(strsize, 0, 64*1024, &errstr)) == 0 \|\|
2e437378	87	errstr)
3c0ef626	88	goto fail;
	89	/* The whole group is one bit larger */
	90	dhg->size++;
	91	gen = strsep(&cp, " "); /* gen */
	92	if (cp == NULL \|\| *gen == '\0')
	93	goto fail;
	94	prime = strsep(&cp, " "); /* prime */
	95	if (cp != NULL \|\| *prime == '\0')
	96	goto fail;
	97
e9a17296	98	if ((dhg->g = BN_new()) == NULL)
	99	fatal("parse_prime: BN_new failed");
	100	if ((dhg->p = BN_new()) == NULL)
	101	fatal("parse_prime: BN_new failed");
3c0ef626	102	if (BN_hex2bn(&dhg->g, gen) == 0)
	103	goto failclean;
	104
	105	if (BN_hex2bn(&dhg->p, prime) == 0)
	106	goto failclean;
	107
	108	if (BN_num_bits(dhg->p) != dhg->size)
	109	goto failclean;
	110
2a304a95	111	if (BN_is_zero(dhg->g) \|\| BN_is_one(dhg->g))
	112	goto failclean;
	113
3c0ef626	114	return (1);
	115
	116	failclean:
e9a17296	117	BN_clear_free(dhg->g);
e9a17296	118	BN_clear_free(dhg->p);
3c0ef626	119	fail:
	120	error("Bad prime description in line %d", linenum);
	121	return (0);
	122	}
	123
	124	DH *
	125	choose_dh(int min, int wantbits, int max)
	126	{
	127	FILE *f;
2a304a95	128	char line[4096];
3c0ef626	129	int best, bestcount, which;
	130	int linenum;
	131	struct dhgroup dhg;
	132
	133	if ((f = fopen(_PATH_DH_MODULI, "r")) == NULL &&
	134	(f = fopen(_PATH_DH_PRIMES, "r")) == NULL) {
1b56ff3d	135	logit("WARNING: %s does not exist, using fixed modulus",
	136	_PATH_DH_MODULI);
	137	return (dh_new_group14());
3c0ef626	138	}
	139
	140	linenum = 0;
	141	best = bestcount = 0;
	142	while (fgets(line, sizeof(line), f)) {
	143	linenum++;
	144	if (!parse_prime(linenum, line, &dhg))
	145	continue;
e9a17296	146	BN_clear_free(dhg.g);
e9a17296	147	BN_clear_free(dhg.p);
3c0ef626	148
	149	if (dhg.size > max \|\| dhg.size < min)
	150	continue;
	151
	152	if ((dhg.size > wantbits && dhg.size < best) \|\|
	153	(dhg.size > best && best < wantbits)) {
	154	best = dhg.size;
	155	bestcount = 0;
	156	}
	157	if (dhg.size == best)
	158	bestcount++;
	159	}
	160	rewind(f);
	161
	162	if (bestcount == 0) {
	163	fclose(f);
70791e56	164	logit("WARNING: no suitable primes in %s", _PATH_DH_PRIMES);
1b56ff3d	165	return (dh_new_group14());
3c0ef626	166	}
	167
	168	linenum = 0;
6f25cbdd	169	which = arc4random_uniform(bestcount);
3c0ef626	170	while (fgets(line, sizeof(line), f)) {
	171	if (!parse_prime(linenum, line, &dhg))
	172	continue;
	173	if ((dhg.size > max \|\| dhg.size < min) \|\|
	174	dhg.size != best \|\|
	175	linenum++ != which) {
e9a17296	176	BN_clear_free(dhg.g);
e9a17296	177	BN_clear_free(dhg.p);
3c0ef626	178	continue;
	179	}
	180	break;
	181	}
	182	fclose(f);
	183	if (linenum != which+1)
	184	fatal("WARNING: line %d disappeared in %s, giving up",
	185	which, _PATH_DH_PRIMES);
	186
	187	return (dh_new_group(dhg.g, dhg.p));
	188	}
	189
1b56ff3d	190	/* diffie-hellman-groupN-sha1 */
3c0ef626	191
	192	int
	193	dh_pub_is_valid(DH dh, BIGNUM dh_pub)
	194	{
	195	int i;
	196	int n = BN_num_bits(dh_pub);
	197	int bits_set = 0;
2e437378	198	BIGNUM *tmp;
3c0ef626	199
3c0ef626	200	if (dh_pub->neg) {
bd5d5d2a	201	logit("invalid public DH value: negative");
3c0ef626	202	return 0;
3c0ef626	203	}
2e437378	204	if (BN_cmp(dh_pub, BN_value_one()) != 1) { /* pub_exp <= 1 */
	205	logit("invalid public DH value: <= 1");
	206	return 0;
	207	}
	208
bd5d5d2a	209	if ((tmp = BN_new()) == NULL) {
	210	error("%s: BN_new failed", __func__);
	211	return 0;
	212	}
2e437378	213	if (!BN_sub(tmp, dh->p, BN_value_one()) \|\|
	214	BN_cmp(dh_pub, tmp) != -1) { /* pub_exp > p-2 */
	215	BN_clear_free(tmp);
	216	logit("invalid public DH value: >= p-1");
	217	return 0;
	218	}
	219	BN_clear_free(tmp);
	220
3c0ef626	221	for (i = 0; i <= n; i++)
	222	if (BN_is_bit_set(dh_pub, i))
	223	bits_set++;
1c14df9e	224	debug2("bits set: %d/%d", bits_set, BN_num_bits(dh->p));
3c0ef626	225
3c0ef626	226	/* if g==2 and bits_set==1 then computing log_g(dh_pub) is trivial */
2e437378	227	if (bits_set > 1)
3c0ef626	228	return 1;
2e437378	229
70791e56	230	logit("invalid public DH value (%d/%d)", bits_set, BN_num_bits(dh->p));
3c0ef626	231	return 0;
	232	}
	233
	234	void
	235	dh_gen_key(DH *dh, int need)
	236	{
2a304a95	237	int i, bits_set, tries = 0;
3c0ef626	238
	239	if (dh->p == NULL)
	240	fatal("dh_gen_key: dh->p == NULL");
416fd2a8	241	if (need > INT_MAX / 2 \|\| 2 * need >= BN_num_bits(dh->p))
3c0ef626	242	fatal("dh_gen_key: group too small: %d (2*need %d)",
	243	BN_num_bits(dh->p), 2*need);
	244	do {
	245	if (dh->priv_key != NULL)
e9a17296	246	BN_clear_free(dh->priv_key);
e9a17296	247	if ((dh->priv_key = BN_new()) == NULL)
3c0ef626	248	fatal("dh_gen_key: BN_new failed");
	249	/* generate a 2need bits random private exponent /
	250	if (!BN_rand(dh->priv_key, 2*need, 0, 0))
	251	fatal("dh_gen_key: BN_rand failed");
	252	if (DH_generate_key(dh) == 0)
	253	fatal("DH_generate_key");
2a304a95	254	for (i = 0, bits_set = 0; i <= BN_num_bits(dh->priv_key); i++)
3c0ef626	255	if (BN_is_bit_set(dh->priv_key, i))
3c0ef626	256	bits_set++;
1c14df9e	257	debug2("dh_gen_key: priv key bits set: %d/%d",
3c0ef626	258	bits_set, BN_num_bits(dh->priv_key));
	259	if (tries++ > 10)
	260	fatal("dh_gen_key: too many bad keys: giving up");
	261	} while (!dh_pub_is_valid(dh, dh->pub_key));
	262	}
	263
	264	DH *
	265	dh_new_group_asc(const char gen, const char modulus)
	266	{
	267	DH *dh;
	268
e9a17296	269	if ((dh = DH_new()) == NULL)
e9a17296	270	fatal("dh_new_group_asc: DH_new");
3c0ef626	271
	272	if (BN_hex2bn(&dh->p, modulus) == 0)
	273	fatal("BN_hex2bn p");
	274	if (BN_hex2bn(&dh->g, gen) == 0)
	275	fatal("BN_hex2bn g");
	276
	277	return (dh);
	278	}
	279
	280	/*
	281	* This just returns the group, we still need to generate the exchange
	282	* value.
	283	*/
	284
	285	DH *
	286	dh_new_group(BIGNUM gen, BIGNUM modulus)
	287	{
	288	DH *dh;
	289
e9a17296	290	if ((dh = DH_new()) == NULL)
e9a17296	291	fatal("dh_new_group: DH_new");
3c0ef626	292	dh->p = modulus;
	293	dh->g = gen;
	294
	295	return (dh);
	296	}
	297
	298	DH *
	299	dh_new_group1(void)
	300	{
	301	static char gen = "2", group1 =
	302	"FFFFFFFF" "FFFFFFFF" "C90FDAA2" "2168C234" "C4C6628B" "80DC1CD1"
	303	"29024E08" "8A67CC74" "020BBEA6" "3B139B22" "514A0879" "8E3404DD"
	304	"EF9519B3" "CD3A431B" "302B0A6D" "F25F1437" "4FE1356D" "6D51C245"
	305	"E485B576" "625E7EC6" "F44C42E9" "A637ED6B" "0BFF5CB6" "F406B7ED"
	306	"EE386BFB" "5A899FA5" "AE9F2411" "7C4B1FE6" "49286651" "ECE65381"
	307	"FFFFFFFF" "FFFFFFFF";
	308
	309	return (dh_new_group_asc(gen, group1));
	310	}
	311
1b56ff3d	312	DH *
	313	dh_new_group14(void)
	314	{
	315	static char gen = "2", group14 =
	316	"FFFFFFFF" "FFFFFFFF" "C90FDAA2" "2168C234" "C4C6628B" "80DC1CD1"
	317	"29024E08" "8A67CC74" "020BBEA6" "3B139B22" "514A0879" "8E3404DD"
	318	"EF9519B3" "CD3A431B" "302B0A6D" "F25F1437" "4FE1356D" "6D51C245"
	319	"E485B576" "625E7EC6" "F44C42E9" "A637ED6B" "0BFF5CB6" "F406B7ED"
	320	"EE386BFB" "5A899FA5" "AE9F2411" "7C4B1FE6" "49286651" "ECE45B3D"
	321	"C2007CB8" "A163BF05" "98DA4836" "1C55D39A" "69163FA8" "FD24CF5F"
	322	"83655D23" "DCA3AD96" "1C62F356" "208552BB" "9ED52907" "7096966D"
	323	"670C354E" "4ABC9804" "F1746C08" "CA18217C" "32905E46" "2E36CE3B"
	324	"E39E772C" "180E8603" "9B2783A2" "EC07A28F" "B5C55DF0" "6F4C52C9"
	325	"DE2BCBF6" "95581718" "3995497C" "EA956AE5" "15D22618" "98FA0510"
	326	"15728E5A" "8AACAA68" "FFFFFFFF" "FFFFFFFF";
	327
	328	return (dh_new_group_asc(gen, group14));
	329	}
	330
3c0ef626	331	/*
	332	* Estimates the group order for a Diffie-Hellman group that has an
	333	* attack complexity approximately the same as O(2**bits). Estimate
	334	* with: O(exp(1.9223 * (ln q)^(1/3) (ln ln q)^(2/3)))
	335	*/
	336
	337	int
	338	dh_estimate(int bits)
	339	{
	340
416fd2a8	341	if (bits <= 128)
3c0ef626	342	return (1024); /* O(2*86) /
416fd2a8	343	if (bits <= 192)
3c0ef626	344	return (2048); /* O(2*116) /
	345	return (4096); /* O(2*156) /
	346	}