[thirdparty/openssl.git] / crypto / dh / dh_key.c

/* crypto/dh/dh_key.c */
/* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
 * All rights reserved.
 *
 * This package is an SSL implementation written
 * by Eric Young (eay@cryptsoft.com).
 * The implementation was written so as to conform with Netscapes SSL.
 * 
 * This library is free for commercial and non-commercial use as long as
 * the following conditions are aheared to.  The following conditions
 * apply to all code found in this distribution, be it the RC4, RSA,
 * lhash, DES, etc., code; not just the SSL code.  The SSL documentation
 * included with this distribution is covered by the same copyright terms
 * except that the holder is Tim Hudson (tjh@cryptsoft.com).
 * 
 * Copyright remains Eric Young's, and as such any Copyright notices in
 * the code are not to be removed.
 * If this package is used in a product, Eric Young should be given attribution
 * as the author of the parts of the library used.
 * This can be in the form of a textual message at program startup or
 * in documentation (online or textual) provided with the package.
 * 
 * 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 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 acknowledgement:
 *    "This product includes cryptographic software written by
 *     Eric Young (eay@cryptsoft.com)"
 *    The word 'cryptographic' can be left out if the rouines from the library
 *    being used are not cryptographic related :-).
 * 4. If you include any Windows specific code (or a derivative thereof) from 
 *    the apps directory (application code) you must include an acknowledgement:
 *    "This product includes software written by Tim Hudson (tjh@cryptsoft.com)"
 * 
 * THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``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 OR 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.
 * 
 * The licence and distribution terms for any publically available version or
 * derivative of this code cannot be changed.  i.e. this code cannot simply be
 * copied and put under another distribution licence
 * [including the GNU Public Licence.]
 */

#include <stdio.h>
#include "cryptlib.h"
#include <openssl/bn.h>
#include <openssl/rand.h>
#include <openssl/dh.h>
#include <openssl/engine.h>

static int generate_key(DH *dh);
static int compute_key(unsigned char *key, const BIGNUM *pub_key, DH *dh);
static int dh_bn_mod_exp(const DH *dh, BIGNUM *r,
			const BIGNUM *a, const BIGNUM *p,
			const BIGNUM *m, BN_CTX *ctx,
			BN_MONT_CTX *m_ctx);
static int dh_init(DH *dh);
static int dh_finish(DH *dh);

int DH_generate_key(DH *dh)
	{
	return dh->meth->generate_key(dh);
	}

int DH_compute_key(unsigned char *key, const BIGNUM *pub_key, DH *dh)
	{
	return dh->meth->compute_key(key, pub_key, dh);
	}

static DH_METHOD dh_ossl = {
"OpenSSL DH Method",
generate_key,
compute_key,
dh_bn_mod_exp,
dh_init,
dh_finish,
0,
NULL
};

const DH_METHOD *DH_OpenSSL(void)
{
	return &dh_ossl;
}

static int generate_key(DH *dh)
	{
	int ok=0;
	int generate_new_key=0;
	unsigned l;
	BN_CTX *ctx;
	BN_MONT_CTX *mont;
	BIGNUM *pub_key=NULL,*priv_key=NULL;

	ctx = BN_CTX_new();
	if (ctx == NULL) goto err;

	if (dh->priv_key == NULL)
		{
		priv_key=BN_new();
		if (priv_key == NULL) goto err;
		generate_new_key=1;
		}
	else
		priv_key=dh->priv_key;

	if (dh->pub_key == NULL)
		{
		pub_key=BN_new();
		if (pub_key == NULL) goto err;
		}
	else
		pub_key=dh->pub_key;

	if ((dh->method_mont_p == NULL) && (dh->flags & DH_FLAG_CACHE_MONT_P))
		{
		if ((dh->method_mont_p=(char *)BN_MONT_CTX_new()) != NULL)
			if (!BN_MONT_CTX_set((BN_MONT_CTX *)dh->method_mont_p,
				dh->p,ctx)) goto err;
		}
	mont=(BN_MONT_CTX *)dh->method_mont_p;

	if (generate_new_key)
		{
		l = dh->length ? dh->length : BN_num_bits(dh->p)-1; /* secret exponent length */
		if (!BN_rand(priv_key, l, 0, 0)) goto err;
		}
	if (!dh->meth->bn_mod_exp(dh, pub_key, dh->g, priv_key,dh->p,ctx,mont))
		goto err;
		
	dh->pub_key=pub_key;
	dh->priv_key=priv_key;
	ok=1;
err:
	if (ok != 1)
		DHerr(DH_F_DH_GENERATE_KEY,ERR_R_BN_LIB);

	if ((pub_key != NULL)  && (dh->pub_key == NULL))  BN_free(pub_key);
	if ((priv_key != NULL) && (dh->priv_key == NULL)) BN_free(priv_key);
	BN_CTX_free(ctx);
	return(ok);
	}

static int compute_key(unsigned char *key, const BIGNUM *pub_key, DH *dh)
	{
	BN_CTX *ctx;
	BN_MONT_CTX *mont;
	BIGNUM *tmp;
	int ret= -1;

	ctx = BN_CTX_new();
	if (ctx == NULL) goto err;
	BN_CTX_start(ctx);
	tmp = BN_CTX_get(ctx);
	
	if (dh->priv_key == NULL)
		{
		DHerr(DH_F_DH_COMPUTE_KEY,DH_R_NO_PRIVATE_VALUE);
		goto err;
		}
	if ((dh->method_mont_p == NULL) && (dh->flags & DH_FLAG_CACHE_MONT_P))
		{
		if ((dh->method_mont_p=(char *)BN_MONT_CTX_new()) != NULL)
			if (!BN_MONT_CTX_set((BN_MONT_CTX *)dh->method_mont_p,
				dh->p,ctx)) goto err;
		}

	mont=(BN_MONT_CTX *)dh->method_mont_p;
	if (!dh->meth->bn_mod_exp(dh, tmp, pub_key, dh->priv_key,dh->p,ctx,mont))
		{
		DHerr(DH_F_DH_COMPUTE_KEY,ERR_R_BN_LIB);
		goto err;
		}

	ret=BN_bn2bin(tmp,key);
err:
	BN_CTX_end(ctx);
	BN_CTX_free(ctx);
	return(ret);
	}

static int dh_bn_mod_exp(const DH *dh, BIGNUM *r,
			const BIGNUM *a, const BIGNUM *p,
			const BIGNUM *m, BN_CTX *ctx,
			BN_MONT_CTX *m_ctx)
	{
	if (a->top == 1)
		{
		BN_ULONG A = a->d[0];
		return BN_mod_exp_mont_word(r,A,p,m,ctx,m_ctx);
		}
	else
		return BN_mod_exp_mont(r,a,p,m,ctx,m_ctx);
	}


static int dh_init(DH *dh)
	{
	dh->flags |= DH_FLAG_CACHE_MONT_P;
	return(1);
	}

static int dh_finish(DH *dh)
	{
	if(dh->method_mont_p)
		BN_MONT_CTX_free((BN_MONT_CTX *)dh->method_mont_p);
	return(1);
	}
Commit	Line	Data
d02b48c6	1	/* crypto/dh/dh_key.c */
58964a49	2	/* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
d02b48c6 RE	3	* All rights reserved.
	4	*
	5	* This package is an SSL implementation written
	6	* by Eric Young (eay@cryptsoft.com).
	7	* The implementation was written so as to conform with Netscapes SSL.
	8	*
	9	* This library is free for commercial and non-commercial use as long as
	10	* the following conditions are aheared to. The following conditions
	11	* apply to all code found in this distribution, be it the RC4, RSA,
	12	* lhash, DES, etc., code; not just the SSL code. The SSL documentation
	13	* included with this distribution is covered by the same copyright terms
	14	* except that the holder is Tim Hudson (tjh@cryptsoft.com).
	15	*
	16	* Copyright remains Eric Young's, and as such any Copyright notices in
	17	* the code are not to be removed.
	18	* If this package is used in a product, Eric Young should be given attribution
	19	* as the author of the parts of the library used.
	20	* This can be in the form of a textual message at program startup or
	21	* in documentation (online or textual) provided with the package.
	22	*
	23	* Redistribution and use in source and binary forms, with or without
	24	* modification, are permitted provided that the following conditions
	25	* are met:
	26	* 1. Redistributions of source code must retain the copyright
	27	* notice, this list of conditions and the following disclaimer.
	28	* 2. Redistributions in binary form must reproduce the above copyright
	29	* notice, this list of conditions and the following disclaimer in the
	30	* documentation and/or other materials provided with the distribution.
	31	* 3. All advertising materials mentioning features or use of this software
	32	* must display the following acknowledgement:
	33	* "This product includes cryptographic software written by
	34	* Eric Young (eay@cryptsoft.com)"
	35	* The word 'cryptographic' can be left out if the rouines from the library
	36	* being used are not cryptographic related :-).
	37	* 4. If you include any Windows specific code (or a derivative thereof) from
	38	* the apps directory (application code) you must include an acknowledgement:
	39	* "This product includes software written by Tim Hudson (tjh@cryptsoft.com)"
	40	*
	41	* THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND
	42	* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
	43	* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
	44	* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
	45	* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
	46	* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
	47	* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
	48	* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
	49	* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
	50	* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
	51	* SUCH DAMAGE.
	52	*
	53	* The licence and distribution terms for any publically available version or
	54	* derivative of this code cannot be changed. i.e. this code cannot simply be
	55	* copied and put under another distribution licence
	56	* [including the GNU Public Licence.]
	57	*/
	58
	59	#include <stdio.h>
	60	#include "cryptlib.h"
ec577822 BM	61	#include <openssl/bn.h>
	62	#include <openssl/rand.h>
	63	#include <openssl/dh.h>
5270e702	64	#include <openssl/engine.h>
d02b48c6	65
13066cee	66	static int generate_key(DH *dh);
f971ccb2 RL	67	static int compute_key(unsigned char key, const BIGNUM pub_key, DH *dh);
	68	static int dh_bn_mod_exp(const DH dh, BIGNUM r,
	69	const BIGNUM a, const BIGNUM p,
13066cee DSH	70	const BIGNUM m, BN_CTX ctx,
	71	BN_MONT_CTX *m_ctx);
	72	static int dh_init(DH *dh);
	73	static int dh_finish(DH *dh);
	74
6b691a5c	75	int DH_generate_key(DH *dh)
13066cee	76	{
cb78486d	77	return dh->meth->generate_key(dh);
13066cee DSH	78	}
13066cee DSH	79
f971ccb2	80	int DH_compute_key(unsigned char key, const BIGNUM pub_key, DH *dh)
13066cee	81	{
cb78486d	82	return dh->meth->compute_key(key, pub_key, dh);
13066cee DSH	83	}
	84
	85	static DH_METHOD dh_ossl = {
	86	"OpenSSL DH Method",
	87	generate_key,
	88	compute_key,
	89	dh_bn_mod_exp,
	90	dh_init,
	91	dh_finish,
	92	0,
	93	NULL
	94	};
	95
f971ccb2	96	const DH_METHOD *DH_OpenSSL(void)
13066cee DSH	97	{
	98	return &dh_ossl;
	99	}
	100
	101	static int generate_key(DH *dh)
d02b48c6 RE	102	{
d02b48c6 RE	103	int ok=0;
924875e5	104	int generate_new_key=0;
6aecef81	105	unsigned l;
c62b26fd	106	BN_CTX *ctx;
dfeab068	107	BN_MONT_CTX *mont;
d02b48c6 RE	108	BIGNUM pub_key=NULL,priv_key=NULL;
d02b48c6 RE	109
c62b26fd BM	110	ctx = BN_CTX_new();
c62b26fd BM	111	if (ctx == NULL) goto err;
d02b48c6 RE	112
	113	if (dh->priv_key == NULL)
	114	{
d02b48c6 RE	115	priv_key=BN_new();
d02b48c6 RE	116	if (priv_key == NULL) goto err;
924875e5	117	generate_new_key=1;
d02b48c6 RE	118	}
	119	else
	120	priv_key=dh->priv_key;
	121
	122	if (dh->pub_key == NULL)
	123	{
	124	pub_key=BN_new();
	125	if (pub_key == NULL) goto err;
	126	}
	127	else
	128	pub_key=dh->pub_key;
	129
dfeab068 RE	130	if ((dh->method_mont_p == NULL) && (dh->flags & DH_FLAG_CACHE_MONT_P))
	131	{
	132	if ((dh->method_mont_p=(char *)BN_MONT_CTX_new()) != NULL)
	133	if (!BN_MONT_CTX_set((BN_MONT_CTX *)dh->method_mont_p,
c62b26fd	134	dh->p,ctx)) goto err;
dfeab068 RE	135	}
	136	mont=(BN_MONT_CTX *)dh->method_mont_p;
	137
924875e5 BM	138	if (generate_new_key)
924875e5 BM	139	{
de3333ba	140	l = dh->length ? dh->length : BN_num_bits(dh->p)-1; /* secret exponent length */
924875e5 BM	141	if (!BN_rand(priv_key, l, 0, 0)) goto err;
924875e5 BM	142	}
cb78486d GT	143	if (!dh->meth->bn_mod_exp(dh, pub_key, dh->g, priv_key,dh->p,ctx,mont))
cb78486d GT	144	goto err;
d02b48c6 RE	145
	146	dh->pub_key=pub_key;
	147	dh->priv_key=priv_key;
	148	ok=1;
	149	err:
	150	if (ok != 1)
	151	DHerr(DH_F_DH_GENERATE_KEY,ERR_R_BN_LIB);
	152
	153	if ((pub_key != NULL) && (dh->pub_key == NULL)) BN_free(pub_key);
	154	if ((priv_key != NULL) && (dh->priv_key == NULL)) BN_free(priv_key);
c62b26fd	155	BN_CTX_free(ctx);
d02b48c6 RE	156	return(ok);
	157	}
	158
f971ccb2	159	static int compute_key(unsigned char key, const BIGNUM pub_key, DH *dh)
d02b48c6	160	{
c62b26fd	161	BN_CTX *ctx;
dfeab068	162	BN_MONT_CTX *mont;
d02b48c6 RE	163	BIGNUM *tmp;
	164	int ret= -1;
	165
c62b26fd BM	166	ctx = BN_CTX_new();
	167	if (ctx == NULL) goto err;
	168	BN_CTX_start(ctx);
	169	tmp = BN_CTX_get(ctx);
d02b48c6 RE	170
	171	if (dh->priv_key == NULL)
	172	{
	173	DHerr(DH_F_DH_COMPUTE_KEY,DH_R_NO_PRIVATE_VALUE);
	174	goto err;
	175	}
dfeab068 RE	176	if ((dh->method_mont_p == NULL) && (dh->flags & DH_FLAG_CACHE_MONT_P))
	177	{
	178	if ((dh->method_mont_p=(char *)BN_MONT_CTX_new()) != NULL)
	179	if (!BN_MONT_CTX_set((BN_MONT_CTX *)dh->method_mont_p,
c62b26fd	180	dh->p,ctx)) goto err;
dfeab068 RE	181	}
	182
	183	mont=(BN_MONT_CTX *)dh->method_mont_p;
cb78486d	184	if (!dh->meth->bn_mod_exp(dh, tmp, pub_key, dh->priv_key,dh->p,ctx,mont))
d02b48c6 RE	185	{
	186	DHerr(DH_F_DH_COMPUTE_KEY,ERR_R_BN_LIB);
	187	goto err;
	188	}
	189
	190	ret=BN_bn2bin(tmp,key);
	191	err:
c62b26fd BM	192	BN_CTX_end(ctx);
c62b26fd BM	193	BN_CTX_free(ctx);
d02b48c6 RE	194	return(ret);
d02b48c6 RE	195	}
13066cee	196
f971ccb2 RL	197	static int dh_bn_mod_exp(const DH dh, BIGNUM r,
f971ccb2 RL	198	const BIGNUM a, const BIGNUM p,
13066cee DSH	199	const BIGNUM m, BN_CTX ctx,
13066cee DSH	200	BN_MONT_CTX *m_ctx)
6dad7bd6 BM	201	{
	202	if (a->top == 1)
	203	{
	204	BN_ULONG A = a->d[0];
	205	return BN_mod_exp_mont_word(r,A,p,m,ctx,m_ctx);
	206	}
	207	else
	208	return BN_mod_exp_mont(r,a,p,m,ctx,m_ctx);
	209	}
	210
13066cee DSH	211
13066cee DSH	212	static int dh_init(DH *dh)
6dad7bd6	213	{
13066cee DSH	214	dh->flags \|= DH_FLAG_CACHE_MONT_P;
13066cee DSH	215	return(1);
6dad7bd6	216	}
13066cee DSH	217
13066cee DSH	218	static int dh_finish(DH *dh)
6dad7bd6	219	{
13066cee DSH	220	if(dh->method_mont_p)
	221	BN_MONT_CTX_free((BN_MONT_CTX *)dh->method_mont_p);
	222	return(1);
6dad7bd6	223	}