[thirdparty/openssl.git] / crypto / dsa / dsa_gen.c

/* crypto/dsa/dsa_gen.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.]
 */

#undef GENUINE_DSA

#ifdef GENUINE_DSA
/* Parameter generation follows the original release of FIPS PUB 186,
 * Appendix 2.2 (i.e. use SHA as defined in FIPS PUB 180) */
#define HASH    EVP_sha()
#else
/* Parameter generation follows the updated Appendix 2.2 for FIPS PUB 186,
 * also Appendix 2.2 of FIPS PUB 186-1 (i.e. use SHA as defined in
 * FIPS PUB 180-1) */
#define HASH    EVP_sha1()
#endif 

#include <openssl/opensslconf.h> /* To see if OPENSSL_NO_SHA is defined */

#ifndef OPENSSL_NO_SHA

#define OPENSSL_FIPSAPI

#include <stdio.h>
#include "cryptlib.h"
#include <openssl/evp.h>
#include <openssl/bn.h>
#include <openssl/rand.h>
#include <openssl/sha.h>
#ifdef OPENSSL_FIPS
#include <openssl/fips.h>
#endif

#include "dsa_locl.h"

int DSA_generate_parameters_ex(DSA *ret, int bits,
		const unsigned char *seed_in, int seed_len,
		int *counter_ret, unsigned long *h_ret, BN_GENCB *cb)
	{
	if(ret->meth->dsa_paramgen)
		return ret->meth->dsa_paramgen(ret, bits, seed_in, seed_len,
				counter_ret, h_ret, cb);
	else
		{
		const EVP_MD *evpmd;
		size_t qbits = bits >= 2048 ? 256 : 160;

		if (bits >= 2048)
			{
			qbits = 256;
			evpmd = EVP_sha256();
			}
		else
			{
			qbits = 160;
			evpmd = EVP_sha1();
			}

		return dsa_builtin_paramgen(ret, bits, qbits, evpmd,
			seed_in, seed_len, NULL, counter_ret, h_ret, cb);
		}
	}

int dsa_builtin_paramgen(DSA *ret, size_t bits, size_t qbits,
	const EVP_MD *evpmd, const unsigned char *seed_in, size_t seed_len,
	unsigned char *seed_out,
	int *counter_ret, unsigned long *h_ret, BN_GENCB *cb)
	{
	int ok=0;
	unsigned char seed[SHA256_DIGEST_LENGTH];
	unsigned char md[SHA256_DIGEST_LENGTH];
	unsigned char buf[SHA256_DIGEST_LENGTH],buf2[SHA256_DIGEST_LENGTH];
	BIGNUM *r0,*W,*X,*c,*test;
	BIGNUM *g=NULL,*q=NULL,*p=NULL;
	BN_MONT_CTX *mont=NULL;
	int i, k, n=0, m=0, qsize = qbits >> 3;
	int counter=0;
	int r=0;
	BN_CTX *ctx=NULL;
	unsigned int h=2;

#ifdef OPENSSL_FIPS
	if(FIPS_selftest_failed())
	    {
	    FIPSerr(FIPS_F_DSA_BUILTIN_PARAMGEN, FIPS_R_FIPS_SELFTEST_FAILED);
	    goto err;
	    }

	if (FIPS_mode() && (bits < OPENSSL_DSA_FIPS_MIN_MODULUS_BITS))
		{
		DSAerr(DSA_F_DSA_BUILTIN_PARAMGEN, DSA_R_KEY_SIZE_TOO_SMALL);
		goto err;
		}
#endif

	if (qsize != SHA_DIGEST_LENGTH && qsize != SHA224_DIGEST_LENGTH &&
	    qsize != SHA256_DIGEST_LENGTH)
		/* invalid q size */
		return 0;

	if (evpmd == NULL)
		/* use SHA1 as default */
		evpmd = EVP_sha1();

	if (bits < 512)
		bits = 512;

	bits = (bits+63)/64*64;

	/* NB: seed_len == 0 is special case: copy generated seed to
 	 * seed_in if it is not NULL.
 	 */
	if (seed_len && (seed_len < (size_t)qsize))
		seed_in = NULL;		/* seed buffer too small -- ignore */
	if (seed_len > (size_t)qsize) 
		seed_len = qsize;	/* App. 2.2 of FIPS PUB 186 allows larger SEED,
					 * but our internal buffers are restricted to 160 bits*/
	if (seed_in != NULL)
		memcpy(seed, seed_in, seed_len);

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

	if ((mont=BN_MONT_CTX_new()) == NULL)
		goto err;

	BN_CTX_start(ctx);
	r0 = BN_CTX_get(ctx);
	g = BN_CTX_get(ctx);
	W = BN_CTX_get(ctx);
	q = BN_CTX_get(ctx);
	X = BN_CTX_get(ctx);
	c = BN_CTX_get(ctx);
	p = BN_CTX_get(ctx);
	test = BN_CTX_get(ctx);

	if (!BN_lshift(test,BN_value_one(),bits-1))
		goto err;

	for (;;)
		{
		for (;;) /* find q */
			{
			int seed_is_random;

			/* step 1 */
			if(!BN_GENCB_call(cb, 0, m++))
				goto err;

			if (!seed_len)
				{
				RAND_pseudo_bytes(seed, qsize);
				seed_is_random = 1;
				}
			else
				{
				seed_is_random = 0;
				seed_len=0; /* use random seed if 'seed_in' turns out to be bad*/
				}
			memcpy(buf , seed, qsize);
			memcpy(buf2, seed, qsize);
			/* precompute "SEED + 1" for step 7: */
			for (i = qsize-1; i >= 0; i--)
				{
				buf[i]++;
				if (buf[i] != 0)
					break;
				}

			/* step 2 */
			if (!EVP_Digest(seed, qsize, md,   NULL, evpmd, NULL))
				goto err;
			if (!EVP_Digest(buf,  qsize, buf2, NULL, evpmd, NULL))
				goto err;
			for (i = 0; i < qsize; i++)
				md[i]^=buf2[i];

			/* step 3 */
			md[0] |= 0x80;
			md[qsize-1] |= 0x01;
			if (!BN_bin2bn(md, qsize, q))
				goto err;

			/* step 4 */
			r = BN_is_prime_fasttest_ex(q, DSS_prime_checks, ctx,
					seed_is_random, cb);
			if (r > 0)
				break;
			if (r != 0)
				goto err;

			/* do a callback call */
			/* step 5 */
			}

		if(!BN_GENCB_call(cb, 2, 0)) goto err;
		if(!BN_GENCB_call(cb, 3, 0)) goto err;

		/* step 6 */
		counter=0;
		/* "offset = 2" */

		n=(bits-1)/160;

		for (;;)
			{
			if ((counter != 0) && !BN_GENCB_call(cb, 0, counter))
				goto err;

			/* step 7 */
			BN_zero(W);
			/* now 'buf' contains "SEED + offset - 1" */
			for (k=0; k<=n; k++)
				{
				/* obtain "SEED + offset + k" by incrementing: */
				for (i = qsize-1; i >= 0; i--)
					{
					buf[i]++;
					if (buf[i] != 0)
						break;
					}

				if (!EVP_Digest(buf, qsize, md ,NULL, evpmd,
									NULL))
					goto err;

				/* step 8 */
				if (!BN_bin2bn(md, qsize, r0))
					goto err;
				if (!BN_lshift(r0,r0,(qsize << 3)*k)) goto err;
				if (!BN_add(W,W,r0)) goto err;
				}

			/* more of step 8 */
			if (!BN_mask_bits(W,bits-1)) goto err;
			if (!BN_copy(X,W)) goto err;
			if (!BN_add(X,X,test)) goto err;

			/* step 9 */
			if (!BN_lshift1(r0,q)) goto err;
			if (!BN_mod(c,X,r0,ctx)) goto err;
			if (!BN_sub(r0,c,BN_value_one())) goto err;
			if (!BN_sub(p,X,r0)) goto err;

			/* step 10 */
			if (BN_cmp(p,test) >= 0)
				{
				/* step 11 */
				r = BN_is_prime_fasttest_ex(p, DSS_prime_checks,
						ctx, 1, cb);
				if (r > 0)
						goto end; /* found it */
				if (r != 0)
					goto err;
				}

			/* step 13 */
			counter++;
			/* "offset = offset + n + 1" */

			/* step 14 */
			if (counter >= 4096) break;
			}
		}
end:
	if(!BN_GENCB_call(cb, 2, 1))
		goto err;

	/* We now need to generate g */
	/* Set r0=(p-1)/q */
	if (!BN_sub(test,p,BN_value_one())) goto err;
	if (!BN_div(r0,NULL,test,q,ctx)) goto err;

	if (!BN_set_word(test,h)) goto err;
	if (!BN_MONT_CTX_set(mont,p,ctx)) goto err;

	for (;;)
		{
		/* g=test^r0%p */
		if (!BN_mod_exp_mont(g,test,r0,p,ctx,mont)) goto err;
		if (!BN_is_one(g)) break;
		if (!BN_add(test,test,BN_value_one())) goto err;
		h++;
		}

	if(!BN_GENCB_call(cb, 3, 1))
		goto err;

	ok=1;
err:
	if (ok)
		{
		if(ret->p) BN_free(ret->p);
		if(ret->q) BN_free(ret->q);
		if(ret->g) BN_free(ret->g);
		ret->p=BN_dup(p);
		ret->q=BN_dup(q);
		ret->g=BN_dup(g);
		if (ret->p == NULL || ret->q == NULL || ret->g == NULL)
			{
			ok=0;
			goto err;
			}
		if (counter_ret != NULL) *counter_ret=counter;
		if (h_ret != NULL) *h_ret=h;
		if (seed_out)
			memcpy(seed_out, seed, qsize);
		}
	if(ctx)
		{
		BN_CTX_end(ctx);
		BN_CTX_free(ctx);
		}
	if (mont != NULL) BN_MONT_CTX_free(mont);
	return ok;
	}

/* Permissible parameter values for (L,N): see FIPS186-3 4.2 */

static int dsa2_check_params(size_t L, size_t N)
	{
	if (L == 1024 && N == 160)
		return 1;
	if (L == 2048 && N == 224)
		return 1;
	if (L == 2048 && N == 256)
		return 1;
	if (L == 3072 && N == 256)
		return 1;
	return 0;
	}

/* This is a parameter generation algorithm for the DSA2 algorithm as
 * described in FIPS 186-3.
 */

int dsa_builtin_paramgen2(DSA *ret, size_t L, size_t N,
	const EVP_MD *evpmd, const unsigned char *seed_in, size_t seed_len,
	unsigned char *seed_out,
	int *counter_ret, unsigned long *h_ret, BN_GENCB *cb)
	{
	int ok=-1;
	unsigned char *seed = NULL;
	unsigned char md[EVP_MAX_MD_SIZE];
	int mdsize;
	BIGNUM *r0,*W,*X,*c,*test;
	BIGNUM *g=NULL,*q=NULL,*p=NULL;
	BN_MONT_CTX *mont=NULL;
	int i, k, n=0, m=0, qsize = N >> 3;
	int counter=0;
	int r=0;
	BN_CTX *ctx=NULL;
	unsigned int h=2;

#ifdef OPENSSL_FIPS
	if(FIPS_selftest_failed())
	    {
	    FIPSerr(FIPS_F_DSA_BUILTIN_PARAMGEN2,
		    FIPS_R_FIPS_SELFTEST_FAILED);
	    goto err;
	    }
#endif
	if (!dsa2_check_params(L, N))
		{
		DSAerr(DSA_F_DSA_BUILTIN_PARAMGEN2, DSA_R_INVALID_PARAMETERS);
		ok = 0;
		goto err;
		}

	if (evpmd == NULL)
		{
		if (N == 160)
			evpmd = EVP_sha1();
		else if (N == 224)
			evpmd = EVP_sha224();
		else
			evpmd = EVP_sha256();
		}

	mdsize = M_EVP_MD_size(evpmd);

	if (seed_len == 0)
		seed_len = mdsize;

	seed = OPENSSL_malloc(seed_len);

	if (!seed)
		goto err;

	if (seed_in)
		memcpy(seed, seed_in, seed_len);

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

	if ((mont=BN_MONT_CTX_new()) == NULL)
		goto err;

	BN_CTX_start(ctx);
	r0 = BN_CTX_get(ctx);
	g = BN_CTX_get(ctx);
	W = BN_CTX_get(ctx);
	q = BN_CTX_get(ctx);
	X = BN_CTX_get(ctx);
	c = BN_CTX_get(ctx);
	p = BN_CTX_get(ctx);
	test = BN_CTX_get(ctx);

	if (!BN_lshift(test,BN_value_one(),L-1))
		goto err;
	for (;;)
		{
		for (;;) /* find q */
			{
			unsigned char *pmd;
			/* step 1 */
			if(!BN_GENCB_call(cb, 0, m++))
				goto err;

			if (!seed_in)
				RAND_pseudo_bytes(seed, qsize);
			/* step 2 */
			if (!EVP_Digest(seed, seed_len, md, NULL, evpmd, NULL))
				goto err;
			/* Take least significant bits of md */
			if (mdsize > qsize)
				pmd = md + mdsize - qsize;
			else
				pmd = md;

			if (mdsize < qsize)
				memset(md + mdsize, 0, qsize - mdsize);

			/* step 3 */
			pmd[0] |= 0x80;
			pmd[qsize-1] |= 0x01;
			if (!BN_bin2bn(pmd, qsize, q))
				goto err;

			/* step 4 */
			r = BN_is_prime_fasttest_ex(q, DSS_prime_checks, ctx,
					seed_in ? 1 : 0, cb);
			if (r > 0)
				break;
			if (r != 0)
				goto err;
			/* Provided seed didn't produce a prime: error */
			if (seed_in)
				{
				ok = 0;
				DSAerr(DSA_F_DSA_BUILTIN_PARAMGEN2, DSA_R_Q_NOT_PRIME);
				goto err;
				}

			/* do a callback call */
			/* step 5 */
			}

		if(!BN_GENCB_call(cb, 2, 0)) goto err;
		if(!BN_GENCB_call(cb, 3, 0)) goto err;

		/* step 6 */
		counter=0;
		/* "offset = 1" */

		n=(L-1)/(mdsize << 3);

		for (;;)
			{
			if ((counter != 0) && !BN_GENCB_call(cb, 0, counter))
				goto err;

			/* step 7 */
			BN_zero(W);
			/* now 'buf' contains "SEED + offset - 1" */
			for (k=0; k<=n; k++)
				{
				/* obtain "SEED + offset + k" by incrementing: */
				for (i = seed_len-1; i >= 0; i--)
					{
					seed[i]++;
					if (seed[i] != 0)
						break;
					}

				if (!EVP_Digest(seed, seed_len, md ,NULL, evpmd,
									NULL))
					goto err;

				/* step 8 */
				if (!BN_bin2bn(md, mdsize, r0))
					goto err;
				if (!BN_lshift(r0,r0,(mdsize << 3)*k)) goto err;
				if (!BN_add(W,W,r0)) goto err;
				}

			/* more of step 8 */
			if (!BN_mask_bits(W,L-1)) goto err;
			if (!BN_copy(X,W)) goto err;
			if (!BN_add(X,X,test)) goto err;

			/* step 9 */
			if (!BN_lshift1(r0,q)) goto err;
			if (!BN_mod(c,X,r0,ctx)) goto err;
			if (!BN_sub(r0,c,BN_value_one())) goto err;
			if (!BN_sub(p,X,r0)) goto err;

			/* step 10 */
			if (BN_cmp(p,test) >= 0)
				{
				/* step 11 */
				r = BN_is_prime_fasttest_ex(p, DSS_prime_checks,
						ctx, 1, cb);
				if (r > 0)
						goto end; /* found it */
				if (r != 0)
					goto err;
				}

			/* step 13 */
			counter++;
			/* "offset = offset + n + 1" */

			/* step 14 */
			if (counter >= 4096) break;
			}
		}
end:
	if(!BN_GENCB_call(cb, 2, 1))
		goto err;

	/* We now need to generate g */
	/* Set r0=(p-1)/q */
	if (!BN_sub(test,p,BN_value_one())) goto err;
	if (!BN_div(r0,NULL,test,q,ctx)) goto err;

	if (!BN_set_word(test,h)) goto err;
	if (!BN_MONT_CTX_set(mont,p,ctx)) goto err;

	for (;;)
		{
		/* g=test^r0%p */
		if (!BN_mod_exp_mont(g,test,r0,p,ctx,mont)) goto err;
		if (!BN_is_one(g)) break;
		if (!BN_add(test,test,BN_value_one())) goto err;
		h++;
		}

	if(!BN_GENCB_call(cb, 3, 1))
		goto err;

	ok=1;
err:
	if (ok)
		{
		if(ret->p) BN_free(ret->p);
		if(ret->q) BN_free(ret->q);
		if(ret->g) BN_free(ret->g);
		ret->p=BN_dup(p);
		ret->q=BN_dup(q);
		ret->g=BN_dup(g);
		if (ret->p == NULL || ret->q == NULL || ret->g == NULL)
			{
			ok=-1;
			goto err;
			}
		if (counter_ret != NULL) *counter_ret=counter;
		if (h_ret != NULL) *h_ret=h;
		if (seed_out)
			memcpy(seed_out, seed, seed_len);
		}
	if (seed)
		OPENSSL_free(seed);
	if(ctx)
		{
		BN_CTX_end(ctx);
		BN_CTX_free(ctx);
		}
	if (mont != NULL) BN_MONT_CTX_free(mont);
	return ok;
	}
#endif
Commit	Line	Data
d02b48c6	1	/* crypto/dsa/dsa_gen.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	#undef GENUINE_DSA
	60
	61	#ifdef GENUINE_DSA
a87030a1 BM	62	/* Parameter generation follows the original release of FIPS PUB 186,
a87030a1 BM	63	* Appendix 2.2 (i.e. use SHA as defined in FIPS PUB 180) */
323f289c	64	#define HASH EVP_sha()
d02b48c6	65	#else
a87030a1 BM	66	/* Parameter generation follows the updated Appendix 2.2 for FIPS PUB 186,
	67	* also Appendix 2.2 of FIPS PUB 186-1 (i.e. use SHA as defined in
	68	* FIPS PUB 180-1) */
323f289c	69	#define HASH EVP_sha1()
d02b48c6 RE	70	#endif
d02b48c6 RE	71
751ff1d3 RL	72	#include <openssl/opensslconf.h> /* To see if OPENSSL_NO_SHA is defined */
751ff1d3 RL	73
cf1b7d96	74	#ifndef OPENSSL_NO_SHA
a87030a1	75
7c8ced94	76	#define OPENSSL_FIPSAPI
20818e00	77
d02b48c6	78	#include <stdio.h>
d02b48c6	79	#include "cryptlib.h"
323f289c	80	#include <openssl/evp.h>
ec577822	81	#include <openssl/bn.h>
ec577822	82	#include <openssl/rand.h>
dbad1690	83	#include <openssl/sha.h>
20818e00 DSH	84	#ifdef OPENSSL_FIPS
	85	#include <openssl/fips.h>
	86	#endif
	87
357d5de5	88	#include "dsa_locl.h"
0e4aa0d2	89
e9224c71	90	int DSA_generate_parameters_ex(DSA *ret, int bits,
1457619e	91	const unsigned char *seed_in, int seed_len,
e9224c71	92	int counter_ret, unsigned long h_ret, BN_GENCB *cb)
d02b48c6	93	{
0e4aa0d2 GT	94	if(ret->meth->dsa_paramgen)
	95	return ret->meth->dsa_paramgen(ret, bits, seed_in, seed_len,
	96	counter_ret, h_ret, cb);
357d5de5 NL	97	else
	98	{
	99	const EVP_MD *evpmd;
	100	size_t qbits = bits >= 2048 ? 256 : 160;
	101
	102	if (bits >= 2048)
	103	{
	104	qbits = 256;
	105	evpmd = EVP_sha256();
	106	}
	107	else
	108	{
	109	qbits = 160;
	110	evpmd = EVP_sha1();
	111	}
	112
	113	return dsa_builtin_paramgen(ret, bits, qbits, evpmd,
198ce9a6	114	seed_in, seed_len, NULL, counter_ret, h_ret, cb);
357d5de5	115	}
0e4aa0d2 GT	116	}
0e4aa0d2 GT	117
357d5de5	118	int dsa_builtin_paramgen(DSA *ret, size_t bits, size_t qbits,
1457619e	119	const EVP_MD evpmd, const unsigned char seed_in, size_t seed_len,
198ce9a6	120	unsigned char *seed_out,
357d5de5	121	int counter_ret, unsigned long h_ret, BN_GENCB *cb)
0e4aa0d2	122	{
d02b48c6	123	int ok=0;
357d5de5 NL	124	unsigned char seed[SHA256_DIGEST_LENGTH];
	125	unsigned char md[SHA256_DIGEST_LENGTH];
	126	unsigned char buf[SHA256_DIGEST_LENGTH],buf2[SHA256_DIGEST_LENGTH];
d02b48c6 RE	127	BIGNUM r0,W,X,c,*test;
d02b48c6 RE	128	BIGNUM g=NULL,q=NULL,*p=NULL;
dfeab068	129	BN_MONT_CTX *mont=NULL;
c8bbd98a	130	int i, k, n=0, m=0, qsize = qbits >> 3;
d02b48c6	131	int counter=0;
a87030a1	132	int r=0;
08e1cbc6	133	BN_CTX *ctx=NULL;
d02b48c6	134	unsigned int h=2;
d02b48c6	135
20818e00 DSH	136	#ifdef OPENSSL_FIPS
	137	if(FIPS_selftest_failed())
	138	{
3dd9b31d	139	FIPSerr(FIPS_F_DSA_BUILTIN_PARAMGEN, FIPS_R_FIPS_SELFTEST_FAILED);
20818e00 DSH	140	goto err;
	141	}
	142
	143	if (FIPS_mode() && (bits < OPENSSL_DSA_FIPS_MIN_MODULUS_BITS))
	144	{
	145	DSAerr(DSA_F_DSA_BUILTIN_PARAMGEN, DSA_R_KEY_SIZE_TOO_SMALL);
	146	goto err;
	147	}
	148	#endif
	149
357d5de5 NL	150	if (qsize != SHA_DIGEST_LENGTH && qsize != SHA224_DIGEST_LENGTH &&
	151	qsize != SHA256_DIGEST_LENGTH)
	152	/* invalid q size */
	153	return 0;
d02b48c6	154
357d5de5 NL	155	if (evpmd == NULL)
	156	/* use SHA1 as default */
	157	evpmd = EVP_sha1();
d02b48c6	158
357d5de5 NL	159	if (bits < 512)
357d5de5 NL	160	bits = 512;
dfeab068	161
357d5de5 NL	162	bits = (bits+63)/64*64;
357d5de5 NL	163
fcd1cb66 DSH	164	/* NB: seed_len == 0 is special case: copy generated seed to
	165	* seed_in if it is not NULL.
	166	*/
	167	if (seed_len && (seed_len < (size_t)qsize))
357d5de5	168	seed_in = NULL; /* seed buffer too small -- ignore */
3627fedb	169	if (seed_len > (size_t)qsize)
357d5de5 NL	170	seed_len = qsize; /* App. 2.2 of FIPS PUB 186 allows larger SEED,
	171	* but our internal buffers are restricted to 160 bits*/
	172	if (seed_in != NULL)
	173	memcpy(seed, seed_in, seed_len);
	174
	175	if ((ctx=BN_CTX_new()) == NULL)
	176	goto err;
	177
	178	if ((mont=BN_MONT_CTX_new()) == NULL)
	179	goto err;
dfeab068	180
08e1cbc6 GT	181	BN_CTX_start(ctx);
	182	r0 = BN_CTX_get(ctx);
	183	g = BN_CTX_get(ctx);
	184	W = BN_CTX_get(ctx);
	185	q = BN_CTX_get(ctx);
	186	X = BN_CTX_get(ctx);
	187	c = BN_CTX_get(ctx);
	188	p = BN_CTX_get(ctx);
	189	test = BN_CTX_get(ctx);
d02b48c6	190
41c70d47 DSH	191	if (!BN_lshift(test,BN_value_one(),bits-1))
41c70d47 DSH	192	goto err;
d02b48c6 RE	193
	194	for (;;)
	195	{
a87030a1	196	for (;;) /* find q */
d02b48c6	197	{
7865b871	198	int seed_is_random;
a87030a1	199
d02b48c6	200	/* step 1 */
e9224c71 GT	201	if(!BN_GENCB_call(cb, 0, m++))
e9224c71 GT	202	goto err;
d02b48c6 RE	203
d02b48c6 RE	204	if (!seed_len)
a87030a1	205	{
357d5de5	206	RAND_pseudo_bytes(seed, qsize);
a87030a1 BM	207	seed_is_random = 1;
a87030a1 BM	208	}
d02b48c6	209	else
7865b871 BM	210	{
	211	seed_is_random = 0;
	212	seed_len=0; /* use random seed if 'seed_in' turns out to be bad*/
	213	}
357d5de5 NL	214	memcpy(buf , seed, qsize);
357d5de5 NL	215	memcpy(buf2, seed, qsize);
a87030a1	216	/* precompute "SEED + 1" for step 7: */
357d5de5	217	for (i = qsize-1; i >= 0; i--)
d02b48c6 RE	218	{
d02b48c6 RE	219	buf[i]++;
357d5de5 NL	220	if (buf[i] != 0)
357d5de5 NL	221	break;
d02b48c6 RE	222	}
	223
	224	/* step 2 */
b6dcdbfc DSH	225	if (!EVP_Digest(seed, qsize, md, NULL, evpmd, NULL))
	226	goto err;
	227	if (!EVP_Digest(buf, qsize, buf2, NULL, evpmd, NULL))
	228	goto err;
357d5de5	229	for (i = 0; i < qsize; i++)
d02b48c6 RE	230	md[i]^=buf2[i];
	231
	232	/* step 3 */
357d5de5 NL	233	md[0] \|= 0x80;
	234	md[qsize-1] \|= 0x01;
	235	if (!BN_bin2bn(md, qsize, q))
	236	goto err;
d02b48c6 RE	237
d02b48c6 RE	238	/* step 4 */
08e1cbc6	239	r = BN_is_prime_fasttest_ex(q, DSS_prime_checks, ctx,
e9224c71	240	seed_is_random, cb);
a87030a1	241	if (r > 0)
aff0825c	242	break;
a87030a1	243	if (r != 0)
aff0825c	244	goto err;
a87030a1	245
d02b48c6 RE	246	/* do a callback call */
	247	/* step 5 */
	248	}
	249
e9224c71 GT	250	if(!BN_GENCB_call(cb, 2, 0)) goto err;
e9224c71 GT	251	if(!BN_GENCB_call(cb, 3, 0)) goto err;
d02b48c6 RE	252
	253	/* step 6 */
	254	counter=0;
a87030a1	255	/* "offset = 2" */
d02b48c6 RE	256
d02b48c6 RE	257	n=(bits-1)/160;
d02b48c6 RE	258
	259	for (;;)
	260	{
e9224c71 GT	261	if ((counter != 0) && !BN_GENCB_call(cb, 0, counter))
e9224c71 GT	262	goto err;
a87030a1	263
d02b48c6	264	/* step 7 */
c01d2b97	265	BN_zero(W);
a87030a1	266	/* now 'buf' contains "SEED + offset - 1" */
d02b48c6 RE	267	for (k=0; k<=n; k++)
d02b48c6 RE	268	{
a87030a1	269	/* obtain "SEED + offset + k" by incrementing: */
357d5de5	270	for (i = qsize-1; i >= 0; i--)
d02b48c6 RE	271	{
d02b48c6 RE	272	buf[i]++;
357d5de5 NL	273	if (buf[i] != 0)
357d5de5 NL	274	break;
d02b48c6 RE	275	}
d02b48c6 RE	276
b6dcdbfc DSH	277	if (!EVP_Digest(buf, qsize, md ,NULL, evpmd,
	278	NULL))
	279	goto err;
d02b48c6 RE	280
d02b48c6 RE	281	/* step 8 */
357d5de5	282	if (!BN_bin2bn(md, qsize, r0))
38e33cef	283	goto err;
357d5de5	284	if (!BN_lshift(r0,r0,(qsize << 3)*k)) goto err;
41c70d47	285	if (!BN_add(W,W,r0)) goto err;
d02b48c6 RE	286	}
	287
	288	/* more of step 8 */
41c70d47 DSH	289	if (!BN_mask_bits(W,bits-1)) goto err;
	290	if (!BN_copy(X,W)) goto err;
	291	if (!BN_add(X,X,test)) goto err;
d02b48c6 RE	292
d02b48c6 RE	293	/* step 9 */
41c70d47 DSH	294	if (!BN_lshift1(r0,q)) goto err;
	295	if (!BN_mod(c,X,r0,ctx)) goto err;
	296	if (!BN_sub(r0,c,BN_value_one())) goto err;
	297	if (!BN_sub(p,X,r0)) goto err;
d02b48c6 RE	298
	299	/* step 10 */
	300	if (BN_cmp(p,test) >= 0)
	301	{
	302	/* step 11 */
e9224c71	303	r = BN_is_prime_fasttest_ex(p, DSS_prime_checks,
08e1cbc6	304	ctx, 1, cb);
a87030a1 BM	305	if (r > 0)
	306	goto end; /* found it */
	307	if (r != 0)
	308	goto err;
d02b48c6 RE	309	}
	310
	311	/* step 13 */
	312	counter++;
a87030a1	313	/* "offset = offset + n + 1" */
d02b48c6 RE	314
	315	/* step 14 */
	316	if (counter >= 4096) break;
d02b48c6 RE	317	}
	318	}
	319	end:
e9224c71 GT	320	if(!BN_GENCB_call(cb, 2, 1))
e9224c71 GT	321	goto err;
d02b48c6	322
38e33cef	323	/* We now need to generate g */
d02b48c6	324	/* Set r0=(p-1)/q */
41c70d47 DSH	325	if (!BN_sub(test,p,BN_value_one())) goto err;
41c70d47 DSH	326	if (!BN_div(r0,NULL,test,q,ctx)) goto err;
d02b48c6	327
41c70d47 DSH	328	if (!BN_set_word(test,h)) goto err;
41c70d47 DSH	329	if (!BN_MONT_CTX_set(mont,p,ctx)) goto err;
dfeab068	330
d02b48c6 RE	331	for (;;)
	332	{
	333	/* g=test^r0%p */
41c70d47	334	if (!BN_mod_exp_mont(g,test,r0,p,ctx,mont)) goto err;
d02b48c6	335	if (!BN_is_one(g)) break;
41c70d47	336	if (!BN_add(test,test,BN_value_one())) goto err;
d02b48c6 RE	337	h++;
	338	}
	339
e9224c71 GT	340	if(!BN_GENCB_call(cb, 3, 1))
e9224c71 GT	341	goto err;
d02b48c6 RE	342
	343	ok=1;
	344	err:
e9224c71	345	if (ok)
d02b48c6	346	{
e9224c71 GT	347	if(ret->p) BN_free(ret->p);
	348	if(ret->q) BN_free(ret->q);
	349	if(ret->g) BN_free(ret->g);
d02b48c6 RE	350	ret->p=BN_dup(p);
	351	ret->q=BN_dup(q);
	352	ret->g=BN_dup(g);
41c70d47 DSH	353	if (ret->p == NULL \|\| ret->q == NULL \|\| ret->g == NULL)
	354	{
	355	ok=0;
	356	goto err;
	357	}
d02b48c6 RE	358	if (counter_ret != NULL) *counter_ret=counter;
d02b48c6 RE	359	if (h_ret != NULL) *h_ret=h;
198ce9a6 DSH	360	if (seed_out)
198ce9a6 DSH	361	memcpy(seed_out, seed, qsize);
d02b48c6	362	}
08e1cbc6	363	if(ctx)
9b141126	364	{
08e1cbc6 GT	365	BN_CTX_end(ctx);
08e1cbc6 GT	366	BN_CTX_free(ctx);
9b141126	367	}
dfeab068	368	if (mont != NULL) BN_MONT_CTX_free(mont);
e9224c71	369	return ok;
d02b48c6	370	}
3dd9b31d DSH	371
	372	/* Permissible parameter values for (L,N): see FIPS186-3 4.2 */
	373
	374	static int dsa2_check_params(size_t L, size_t N)
	375	{
	376	if (L == 1024 && N == 160)
	377	return 1;
	378	if (L == 2048 && N == 224)
	379	return 1;
	380	if (L == 2048 && N == 256)
	381	return 1;
	382	if (L == 3072 && N == 256)
	383	return 1;
	384	return 0;
	385	}
	386
	387	/* This is a parameter generation algorithm for the DSA2 algorithm as
	388	* described in FIPS 186-3.
	389	*/
	390
	391	int dsa_builtin_paramgen2(DSA *ret, size_t L, size_t N,
	392	const EVP_MD evpmd, const unsigned char seed_in, size_t seed_len,
	393	unsigned char *seed_out,
	394	int counter_ret, unsigned long h_ret, BN_GENCB *cb)
	395	{
	396	int ok=-1;
	397	unsigned char *seed = NULL;
	398	unsigned char md[EVP_MAX_MD_SIZE];
	399	int mdsize;
	400	BIGNUM r0,W,X,c,*test;
	401	BIGNUM g=NULL,q=NULL,*p=NULL;
	402	BN_MONT_CTX *mont=NULL;
	403	int i, k, n=0, m=0, qsize = N >> 3;
	404	int counter=0;
	405	int r=0;
	406	BN_CTX *ctx=NULL;
	407	unsigned int h=2;
	408
	409	#ifdef OPENSSL_FIPS
	410	if(FIPS_selftest_failed())
	411	{
	412	FIPSerr(FIPS_F_DSA_BUILTIN_PARAMGEN2,
	413	FIPS_R_FIPS_SELFTEST_FAILED);
	414	goto err;
	415	}
	416	#endif
	417	if (!dsa2_check_params(L, N))
	418	{
	419	DSAerr(DSA_F_DSA_BUILTIN_PARAMGEN2, DSA_R_INVALID_PARAMETERS);
	420	ok = 0;
	421	goto err;
	422	}
	423
	424	if (evpmd == NULL)
	425	{
	426	if (N == 160)
	427	evpmd = EVP_sha1();
	428	else if (N == 224)
	429	evpmd = EVP_sha224();
	430	else
	431	evpmd = EVP_sha256();
	432	}
	433
	434	mdsize = M_EVP_MD_size(evpmd);
435
436	if (seed_len == 0)
437	seed_len = mdsize;
438
439	seed = OPENSSL_malloc(seed_len);
440
441	if (!seed)
442	goto err;
443
444	if (seed_in)
445	memcpy(seed, seed_in, seed_len);
446
447	if ((ctx=BN_CTX_new()) == NULL)
448	goto err;
449
450	if ((mont=BN_MONT_CTX_new()) == NULL)
451	goto err;
452
453	BN_CTX_start(ctx);
454	r0 = BN_CTX_get(ctx);
455	g = BN_CTX_get(ctx);
456	W = BN_CTX_get(ctx);
457	q = BN_CTX_get(ctx);
458	X = BN_CTX_get(ctx);
459	c = BN_CTX_get(ctx);
460	p = BN_CTX_get(ctx);
461	test = BN_CTX_get(ctx);
462
463	if (!BN_lshift(test,BN_value_one(),L-1))
464	goto err;
465	for (;;)
466	{
467	for (;;) /* find q */
468	{
469	unsigned char *pmd;
470	/* step 1 */
471	if(!BN_GENCB_call(cb, 0, m++))
472	goto err;
473
474	if (!seed_in)
475	RAND_pseudo_bytes(seed, qsize);
476	/* step 2 */
477	if (!EVP_Digest(seed, seed_len, md, NULL, evpmd, NULL))
478	goto err;
479	/* Take least significant bits of md */
480	if (mdsize > qsize)
481	pmd = md + mdsize - qsize;
482	else
483	pmd = md;
484
485	if (mdsize < qsize)
486	memset(md + mdsize, 0, qsize - mdsize);
487
488	/* step 3 */
489	pmd[0] \|= 0x80;
490	pmd[qsize-1] \|= 0x01;
491	if (!BN_bin2bn(pmd, qsize, q))
492	goto err;
493
494	/* step 4 */
495	r = BN_is_prime_fasttest_ex(q, DSS_prime_checks, ctx,
496	seed_in ? 1 : 0, cb);
497	if (r > 0)
498	break;
499	if (r != 0)
500	goto err;
501	/* Provided seed didn't produce a prime: error */
502	if (seed_in)
503	{
504	ok = 0;
505	DSAerr(DSA_F_DSA_BUILTIN_PARAMGEN2, DSA_R_Q_NOT_PRIME);
506	goto err;
507	}
508
509	/* do a callback call */
510	/* step 5 */
511	}
512
513	if(!BN_GENCB_call(cb, 2, 0)) goto err;
514	if(!BN_GENCB_call(cb, 3, 0)) goto err;
515
516	/* step 6 */
517	counter=0;
518	/* "offset = 1" */
519
520	n=(L-1)/(mdsize << 3);
521
522	for (;;)
523	{
524	if ((counter != 0) && !BN_GENCB_call(cb, 0, counter))
525	goto err;
526
527	/* step 7 */
528	BN_zero(W);
529	/* now 'buf' contains "SEED + offset - 1" */
530	for (k=0; k<=n; k++)
531	{
532	/* obtain "SEED + offset + k" by incrementing: */
533	for (i = seed_len-1; i >= 0; i--)
534	{
535	seed[i]++;
536	if (seed[i] != 0)
537	break;
538	}
539
540	if (!EVP_Digest(seed, seed_len, md ,NULL, evpmd,
541	NULL))
542	goto err;
543
544	/* step 8 */
545	if (!BN_bin2bn(md, mdsize, r0))
546	goto err;
547	if (!BN_lshift(r0,r0,(mdsize << 3)*k)) goto err;
548	if (!BN_add(W,W,r0)) goto err;
549	}
550
551	/* more of step 8 */
552	if (!BN_mask_bits(W,L-1)) goto err;
553	if (!BN_copy(X,W)) goto err;
554	if (!BN_add(X,X,test)) goto err;
555
556	/* step 9 */
557	if (!BN_lshift1(r0,q)) goto err;
558	if (!BN_mod(c,X,r0,ctx)) goto err;
559	if (!BN_sub(r0,c,BN_value_one())) goto err;
560	if (!BN_sub(p,X,r0)) goto err;
561
562	/* step 10 */
563	if (BN_cmp(p,test) >= 0)
564	{
565	/* step 11 */
566	r = BN_is_prime_fasttest_ex(p, DSS_prime_checks,
567	ctx, 1, cb);
568	if (r > 0)
569	goto end; /* found it */
570	if (r != 0)
571	goto err;
572	}
573
574	/* step 13 */
575	counter++;
576	/* "offset = offset + n + 1" */
577
578	/* step 14 */
579	if (counter >= 4096) break;
580	}
581	}
582	end:
583	if(!BN_GENCB_call(cb, 2, 1))
584	goto err;
585
586	/* We now need to generate g */
587	/* Set r0=(p-1)/q */
588	if (!BN_sub(test,p,BN_value_one())) goto err;
589	if (!BN_div(r0,NULL,test,q,ctx)) goto err;
590
591	if (!BN_set_word(test,h)) goto err;
592	if (!BN_MONT_CTX_set(mont,p,ctx)) goto err;
593
594	for (;;)
595	{
596	/* g=test^r0%p */
597	if (!BN_mod_exp_mont(g,test,r0,p,ctx,mont)) goto err;
598	if (!BN_is_one(g)) break;
599	if (!BN_add(test,test,BN_value_one())) goto err;
600	h++;
601	}
602
603	if(!BN_GENCB_call(cb, 3, 1))
604	goto err;
605
606	ok=1;
607	err:
608	if (ok)
609	{
610	if(ret->p) BN_free(ret->p);
611	if(ret->q) BN_free(ret->q);
612	if(ret->g) BN_free(ret->g);
613	ret->p=BN_dup(p);
614	ret->q=BN_dup(q);
615	ret->g=BN_dup(g);
616	if (ret->p == NULL \|\| ret->q == NULL \|\| ret->g == NULL)
617	{
618	ok=-1;
619	goto err;
620	}
621	if (counter_ret != NULL) *counter_ret=counter;
622	if (h_ret != NULL) *h_ret=h;
623	if (seed_out)
624	memcpy(seed_out, seed, seed_len);
625	}
626	if (seed)
627	OPENSSL_free(seed);
628	if(ctx)
629	{
630	BN_CTX_end(ctx);
631	BN_CTX_free(ctx);
632	}
633	if (mont != NULL) BN_MONT_CTX_free(mont);
634	return ok;
635	}
d02f751c	636	#endif