crypto/dsa/dsa_gen.c - third_party/openssl - Git at Google

 /* 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
 #define HASH    SHA
 #else
 #define HASH    SHA1
 #endif

 #include <stdio.h>
 #include <time.h>
 #include "cryptlib.h"
 #include "sha.h"
 #include "bn.h"
 #include "dsa.h"
 #include "rand.h"

 DSA *DSA_generate_parameters(int bits, unsigned char *seed_in, int seed_len,
 	     int *counter_ret, unsigned long *h_ret, void (*callback)(),
 	     char *cb_arg)
 	{
 	int ok=0;
 	unsigned char seed[SHA_DIGEST_LENGTH];
 	unsigned char md[SHA_DIGEST_LENGTH];
 	unsigned char buf[SHA_DIGEST_LENGTH],buf2[SHA_DIGEST_LENGTH];
 	BIGNUM *r0,*W,*X,*c,*test;
 	BIGNUM *g=NULL,*q=NULL,*p=NULL;
 	BN_MONT_CTX *mont=NULL;
 	int k,n=0,i,b,m=0;
 	int counter=0;
 	BN_CTX *ctx=NULL,*ctx2=NULL;
 	unsigned int h=2;
 	DSA *ret=NULL;

 	if (bits < 512) bits=512;
 	bits=(bits+63)/64*64;

 	if ((seed_in != NULL) && (seed_len == 20))
 		memcpy(seed,seed_in,seed_len);

 	if ((ctx=BN_CTX_new()) == NULL) goto err;
 	if ((ctx2=BN_CTX_new()) == NULL) goto err;
 	if ((ret=DSA_new()) == NULL) goto err;

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

 	r0= &(ctx2->bn[0]);
 	g= &(ctx2->bn[1]);
 	W= &(ctx2->bn[2]);
 	q= &(ctx2->bn[3]);
 	X= &(ctx2->bn[4]);
 	c= &(ctx2->bn[5]);
 	p= &(ctx2->bn[6]);
 	test= &(ctx2->bn[7]);

 	BN_lshift(test,BN_value_one(),bits-1);

 	for (;;)
 		{
 		for (;;)
 			{
 			/* step 1 */
 			if (callback != NULL) callback(0,m++,cb_arg);

 			if (!seed_len)
 				RAND_bytes(seed,SHA_DIGEST_LENGTH);
 			else
 				seed_len=0;

 			memcpy(buf,seed,SHA_DIGEST_LENGTH);
 			memcpy(buf2,seed,SHA_DIGEST_LENGTH);
 			for (i=SHA_DIGEST_LENGTH-1; i >= 0; i--)
 				{
 				buf[i]++;
 				if (buf[i] != 0) break;
 				}

 			/* step 2 */
 			HASH(seed,SHA_DIGEST_LENGTH,md);
 			HASH(buf,SHA_DIGEST_LENGTH,buf2);
 			for (i=0; i<SHA_DIGEST_LENGTH; i++)
 				md[i]^=buf2[i];

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

 			/* step 4 */
 			if (DSA_is_prime(q,callback,cb_arg) > 0) break;
 			/* do a callback call */
 			/* step 5 */
 			}

 		if (callback != NULL) callback(2,0,cb_arg);
 		if (callback != NULL) callback(3,0,cb_arg);

 		/* step 6 */
 		counter=0;

 		n=(bits-1)/160;
 		b=(bits-1)-n*160;

 		for (;;)
 			{
 			/* step 7 */
 			BN_zero(W);
 			for (k=0; k<=n; k++)
 				{
 				for (i=SHA_DIGEST_LENGTH-1; i >= 0; i--)
 					{
 					buf[i]++;
 					if (buf[i] != 0) break;
 					}

 				HASH(buf,SHA_DIGEST_LENGTH,md);

 				/* step 8 */
 				if (!BN_bin2bn(md,SHA_DIGEST_LENGTH,r0)) abort();
 				BN_lshift(r0,r0,160*k);
 				BN_add(W,W,r0);
 				}

 			/* more of step 8 */
 			BN_mask_bits(W,bits-1);
 			BN_copy(X,W); /* this should be ok */
 			BN_add(X,X,test); /* this should be ok */

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

 			/* step 10 */
 			if (BN_cmp(p,test) >= 0)
 				{
 				/* step 11 */
 				if (DSA_is_prime(p,callback,cb_arg) > 0)
 					goto end;
 				}

 			/* step 13 */
 			counter++;

 			/* step 14 */
 			if (counter >= 4096) break;

 			if (callback != NULL) callback(0,counter,cb_arg);
 			}
 		}
 end:
 	if (callback != NULL) callback(2,1,cb_arg);

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

 	BN_set_word(test,h);
 	BN_MONT_CTX_set(mont,p,ctx);

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

 	if (callback != NULL) callback(3,1,cb_arg);

 	ok=1;
 err:
 	if (!ok)
 		{
 		if (ret != NULL) DSA_free(ret);
 		}
 	else
 		{
 		ret->p=BN_dup(p);
 		ret->q=BN_dup(q);
 		ret->g=BN_dup(g);
 		if ((m > 1) && (seed_in != NULL)) memcpy(seed_in,seed,20);
 		if (counter_ret != NULL) *counter_ret=counter;
 		if (h_ret != NULL) *h_ret=h;
 		}
 	if (ctx != NULL) BN_CTX_free(ctx);
 	if (ctx != NULL) BN_CTX_free(ctx2);
 	if (mont != NULL) BN_MONT_CTX_free(mont);
 	return(ok?ret:NULL);
 	}

 int DSA_is_prime(BIGNUM *w, void (*callback)(), char *cb_arg)
 	{
 	int ok= -1,j,i,n;
 	BN_CTX *ctx=NULL,*ctx2=NULL;
 	BIGNUM *w_1,*b,*m,*z,*tmp,*mont_1;
 	int a;
 	BN_MONT_CTX *mont=NULL;

 	if (!BN_is_bit_set(w,0)) return(0);

 	if ((ctx=BN_CTX_new()) == NULL) goto err;
 	if ((ctx2=BN_CTX_new()) == NULL) goto err;
 	if ((mont=BN_MONT_CTX_new()) == NULL) goto err;

 	m=   &(ctx2->bn[2]);
 	b=   &(ctx2->bn[3]);
 	z=   &(ctx2->bn[4]);
 	w_1= &(ctx2->bn[5]);
 	tmp= &(ctx2->bn[6]);
 	mont_1= &(ctx2->bn[7]);

 	/* step 1 */
 	n=50;

 	/* step 2 */
 	if (!BN_sub(w_1,w,BN_value_one())) goto err;
 	for (a=1; !BN_is_bit_set(w_1,a); a++)
 		;
 	if (!BN_rshift(m,w_1,a)) goto err;

 	BN_MONT_CTX_set(mont,w,ctx);
 	BN_to_montgomery(mont_1,BN_value_one(),mont,ctx);
 	BN_to_montgomery(w_1,w_1,mont,ctx);
 	for (i=1; i < n; i++)
 		{
 		/* step 3 */
 		BN_rand(b,BN_num_bits(w)-2/*-1*/,0,0);
 		/* BN_set_word(b,0x10001L); */

 		/* step 4 */
 		j=0;
 		if (!BN_mod_exp_mont(z,b,m,w,ctx,mont)) goto err;

 		if (!BN_to_montgomery(z,z,mont,ctx)) goto err;

 		/* step 5 */
 		for (;;)
 			{
 			if (((j == 0) && (BN_cmp(z,mont_1) == 0)) ||
 				(BN_cmp(z,w_1) == 0))
 				break;

 			/* step 6 */
 			if ((j > 0) && (BN_cmp(z,mont_1) == 0))
 				{
 				ok=0;
 				goto err;
 				}

 			j++;
 			if (j >= a)
 				{
 				ok=0;
 				goto err;
 				}

 			if (!BN_mod_mul_montgomery(z,z,z,mont,ctx)) goto err;
 			if (callback != NULL) callback(1,j,cb_arg);
 			}
 		}

 	ok=1;
 err:
 	if (ok == -1) DSAerr(DSA_F_DSA_IS_PRIME,ERR_R_BN_LIB);
 	BN_CTX_free(ctx);
 	BN_CTX_free(ctx2);

 	return(ok);
 	}
	/* 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
	#define HASH SHA
	#else
	#define HASH SHA1
	#endif

	#include <stdio.h>
	#include <time.h>
	#include "cryptlib.h"
	#include "sha.h"
	#include "bn.h"
	#include "dsa.h"
	#include "rand.h"

	DSA DSA_generate_parameters(int bits, unsigned char seed_in, int seed_len,
	int counter_ret, unsigned long h_ret, void (*callback)(),
	char *cb_arg)
	{
	int ok=0;
	unsigned char seed[SHA_DIGEST_LENGTH];
	unsigned char md[SHA_DIGEST_LENGTH];
	unsigned char buf[SHA_DIGEST_LENGTH],buf2[SHA_DIGEST_LENGTH];
	BIGNUM r0,W,X,c,*test;
	BIGNUM g=NULL,q=NULL,*p=NULL;
	BN_MONT_CTX *mont=NULL;
	int k,n=0,i,b,m=0;
	int counter=0;
	BN_CTX ctx=NULL,ctx2=NULL;
	unsigned int h=2;
	DSA *ret=NULL;

	if (bits < 512) bits=512;
	bits=(bits+63)/64*64;

	if ((seed_in != NULL) && (seed_len == 20))
	memcpy(seed,seed_in,seed_len);

	if ((ctx=BN_CTX_new()) == NULL) goto err;
	if ((ctx2=BN_CTX_new()) == NULL) goto err;
	if ((ret=DSA_new()) == NULL) goto err;

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

	r0= &(ctx2->bn[0]);
	g= &(ctx2->bn[1]);
	W= &(ctx2->bn[2]);
	q= &(ctx2->bn[3]);
	X= &(ctx2->bn[4]);
	c= &(ctx2->bn[5]);
	p= &(ctx2->bn[6]);
	test= &(ctx2->bn[7]);

	BN_lshift(test,BN_value_one(),bits-1);

	for (;;)
	{
	for (;;)
	{
	/* step 1 */
	if (callback != NULL) callback(0,m++,cb_arg);

	if (!seed_len)
	RAND_bytes(seed,SHA_DIGEST_LENGTH);
	else
	seed_len=0;

	memcpy(buf,seed,SHA_DIGEST_LENGTH);
	memcpy(buf2,seed,SHA_DIGEST_LENGTH);
	for (i=SHA_DIGEST_LENGTH-1; i >= 0; i--)
	{
	buf[i]++;
	if (buf[i] != 0) break;
	}

	/* step 2 */
	HASH(seed,SHA_DIGEST_LENGTH,md);
	HASH(buf,SHA_DIGEST_LENGTH,buf2);
	for (i=0; i<SHA_DIGEST_LENGTH; i++)
	md[i]^=buf2[i];

	/* step 3 */
	md[0]\|=0x80;
	md[SHA_DIGEST_LENGTH-1]\|=0x01;
	if (!BN_bin2bn(md,SHA_DIGEST_LENGTH,q)) abort();

	/* step 4 */
	if (DSA_is_prime(q,callback,cb_arg) > 0) break;
	/* do a callback call */
	/* step 5 */
	}

	if (callback != NULL) callback(2,0,cb_arg);
	if (callback != NULL) callback(3,0,cb_arg);

	/* step 6 */
	counter=0;

	n=(bits-1)/160;
	b=(bits-1)-n*160;

	for (;;)
	{
	/* step 7 */
	BN_zero(W);
	for (k=0; k<=n; k++)
	{
	for (i=SHA_DIGEST_LENGTH-1; i >= 0; i--)
	{
	buf[i]++;
	if (buf[i] != 0) break;
	}

	HASH(buf,SHA_DIGEST_LENGTH,md);

	/* step 8 */
	if (!BN_bin2bn(md,SHA_DIGEST_LENGTH,r0)) abort();
	BN_lshift(r0,r0,160*k);
	BN_add(W,W,r0);
	}

	/* more of step 8 */
	BN_mask_bits(W,bits-1);
	BN_copy(X,W); /* this should be ok */
	BN_add(X,X,test); /* this should be ok */

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

	/* step 10 */
	if (BN_cmp(p,test) >= 0)
	{
	/* step 11 */
	if (DSA_is_prime(p,callback,cb_arg) > 0)
	goto end;
	}

	/* step 13 */
	counter++;

	/* step 14 */
	if (counter >= 4096) break;

	if (callback != NULL) callback(0,counter,cb_arg);
	}
	}
	end:
	if (callback != NULL) callback(2,1,cb_arg);

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

	BN_set_word(test,h);
	BN_MONT_CTX_set(mont,p,ctx);

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

	if (callback != NULL) callback(3,1,cb_arg);

	ok=1;
	err:
	if (!ok)
	{
	if (ret != NULL) DSA_free(ret);
	}
	else
	{
	ret->p=BN_dup(p);
	ret->q=BN_dup(q);
	ret->g=BN_dup(g);
	if ((m > 1) && (seed_in != NULL)) memcpy(seed_in,seed,20);
	if (counter_ret != NULL) *counter_ret=counter;
	if (h_ret != NULL) *h_ret=h;
	}
	if (ctx != NULL) BN_CTX_free(ctx);
	if (ctx != NULL) BN_CTX_free(ctx2);
	if (mont != NULL) BN_MONT_CTX_free(mont);
	return(ok?ret:NULL);
	}

	int DSA_is_prime(BIGNUM w, void (callback)(), char *cb_arg)
	{
	int ok= -1,j,i,n;
	BN_CTX ctx=NULL,ctx2=NULL;
	BIGNUM w_1,b,m,z,tmp,mont_1;
	int a;
	BN_MONT_CTX *mont=NULL;

	if (!BN_is_bit_set(w,0)) return(0);

	if ((ctx=BN_CTX_new()) == NULL) goto err;
	if ((ctx2=BN_CTX_new()) == NULL) goto err;
	if ((mont=BN_MONT_CTX_new()) == NULL) goto err;

	m= &(ctx2->bn[2]);
	b= &(ctx2->bn[3]);
	z= &(ctx2->bn[4]);
	w_1= &(ctx2->bn[5]);
	tmp= &(ctx2->bn[6]);
	mont_1= &(ctx2->bn[7]);

	/* step 1 */
	n=50;

	/* step 2 */
	if (!BN_sub(w_1,w,BN_value_one())) goto err;
	for (a=1; !BN_is_bit_set(w_1,a); a++)
	;
	if (!BN_rshift(m,w_1,a)) goto err;

	BN_MONT_CTX_set(mont,w,ctx);
	BN_to_montgomery(mont_1,BN_value_one(),mont,ctx);
	BN_to_montgomery(w_1,w_1,mont,ctx);
	for (i=1; i < n; i++)
	{
	/* step 3 */
	BN_rand(b,BN_num_bits(w)-2/-1/,0,0);
	/* BN_set_word(b,0x10001L); */

	/* step 4 */
	j=0;
	if (!BN_mod_exp_mont(z,b,m,w,ctx,mont)) goto err;

	if (!BN_to_montgomery(z,z,mont,ctx)) goto err;

	/* step 5 */
	for (;;)
	{
	if (((j == 0) && (BN_cmp(z,mont_1) == 0)) \|\|
	(BN_cmp(z,w_1) == 0))
	break;

	/* step 6 */
	if ((j > 0) && (BN_cmp(z,mont_1) == 0))
	{
	ok=0;
	goto err;
	}

	j++;
	if (j >= a)
	{
	ok=0;
	goto err;
	}

	if (!BN_mod_mul_montgomery(z,z,z,mont,ctx)) goto err;
	if (callback != NULL) callback(1,j,cb_arg);
	}
	}

	ok=1;
	err:
	if (ok == -1) DSAerr(DSA_F_DSA_IS_PRIME,ERR_R_BN_LIB);
	BN_CTX_free(ctx);
	BN_CTX_free(ctx2);

	return(ok);
	}