Commit e74231ed authored by Bodo Möller's avatar Bodo Möller
Browse files

rndsort{Miller, Rabin} primality test.

parent fb81ac5e
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+5 −0
Original line number Diff line number Diff line
@@ -4,6 +4,11 @@

 Changes between 0.9.4 and 0.9.5  [xx XXX 2000]

  *) Use a less unusual form of the Miller-Rabin primality test (it used
     a binary algorithm for exponentiation integrated into the Miller-Rabin
     loop, our standard modexp algorithms are faster).
     [Bodo Moeller]

  *) Support for the EBCDIC character set completed.
     [Martin Kraemer <Martin.Kraemer@Mch.SNI.De>]

+1 −2
Original line number Diff line number Diff line
@@ -407,8 +407,7 @@ BIGNUM *BN_generate_prime(BIGNUM *ret,int bits,int safe,BIGNUM *add,
int	BN_is_prime(BIGNUM *p,int nchecks,void (*callback)(int,int,void *),
		BN_CTX *ctx,void *cb_arg);
int	BN_is_prime_fasttest(BIGNUM *p,int nchecks,
		void (*callback)(int,int,void *),
		BN_CTX *ctx,BN_CTX *ctx2,void *cb_arg,
		void (*callback)(int,int,void *),BN_CTX *ctx,void *cb_arg,
		int do_trial_division);
void	ERR_load_BN_strings(void );

+91 −182
Original line number Diff line number Diff line
@@ -68,8 +68,8 @@
 */
#include "bn_prime.h"

static int witness(BIGNUM *a, BIGNUM *n, BN_CTX *ctx,BN_CTX *ctx2,
	BN_MONT_CTX *mont);
static int witness(BIGNUM *w, BIGNUM *a, BIGNUM *a1, BIGNUM *a1_odd, int k,
	BN_CTX *ctx, BN_MONT_CTX *mont);
static int probable_prime(BIGNUM *rnd, int bits);
static int probable_prime_dh(BIGNUM *rnd, int bits,
	BIGNUM *add, BIGNUM *rem, BN_CTX *ctx);
@@ -83,13 +83,11 @@ BIGNUM *BN_generate_prime(BIGNUM *ret, int bits, int safe, BIGNUM *add,
	BIGNUM t;
	int found=0;
	int i,j,c1=0;
	BN_CTX *ctx,*ctx2=NULL;
	BN_CTX *ctx;
	int checks = BN_prime_checks_for_size(bits);

	ctx=BN_CTX_new();
	if (ctx == NULL) goto err;
	ctx2=BN_CTX_new();
	if (ctx2 == NULL) goto err;
	if (ret == NULL)
		{
		if ((rnd=BN_new()) == NULL) goto err;
@@ -121,7 +119,7 @@ loop:

	if (!safe)
		{
		i=BN_is_prime_fasttest(rnd,checks,callback,ctx,ctx2,cb_arg,0);
		i=BN_is_prime_fasttest(rnd,checks,callback,ctx,cb_arg,0);
		if (i == -1) goto err;
		if (i == 0) goto loop;
		}
@@ -135,11 +133,11 @@ loop:

		for (i=0; i<checks; i++)
			{
			j=BN_is_prime_fasttest(rnd,1,callback,ctx,ctx2,cb_arg,0);
			j=BN_is_prime_fasttest(rnd,1,callback,ctx,cb_arg,0);
			if (j == -1) goto err;
			if (j == 0) goto loop;

			j=BN_is_prime_fasttest(&t,1,callback,ctx,ctx2,cb_arg,0);
			j=BN_is_prime_fasttest(&t,1,callback,ctx,cb_arg,0);
			if (j == -1) goto err;
			if (j == 0) goto loop;

@@ -153,26 +151,33 @@ err:
	if (!found && (ret == NULL) && (rnd != NULL)) BN_free(rnd);
	BN_free(&t);
	if (ctx != NULL) BN_CTX_free(ctx);
	if (ctx2 != NULL) BN_CTX_free(ctx2);
	return(found ? rnd : NULL);
	}

int BN_is_prime(BIGNUM *a, int checks, void (*callback)(int,int,void *),
	BN_CTX *ctx_passed, void *cb_arg)
	{
	return BN_is_prime_fasttest(a, checks, callback, ctx_passed, cb_arg, 0);
	}

int BN_is_prime_fasttest(BIGNUM *a, int checks,
		void (*callback)(int,int,void *),
		BN_CTX *ctx_passed, BN_CTX *ctx2_passed, void *cb_arg,
		BN_CTX *ctx_passed, void *cb_arg,
		int do_trial_division)
	{
	int i, j, ret = -1;
	BIGNUM *check;
	BN_CTX *ctx=NULL,*ctx2=NULL;
	int k;
	BN_CTX *ctx = NULL;
	BIGNUM *a1, *a1_odd, *check; /* taken from ctx */
	BN_MONT_CTX *mont = NULL;

	if (checks == BN_prime_checks)
		{
		int bits = BN_num_bits(a);
		checks = BN_prime_checks_for_size(bits);
		}
		checks = BN_prime_checks_for_size(BN_num_bits(a));

	if (a->neg) /* for now, refuse to handle negative numbers */
		return -1;

	/* first look for small factors */
	if (!BN_is_odd(a))
		return(0);
	if (do_trial_division)
@@ -186,26 +191,49 @@ int BN_is_prime_fasttest(BIGNUM *a, int checks,
	if (ctx_passed != NULL)
		ctx = ctx_passed;
	else
		if ((ctx=BN_CTX_new()) == NULL) goto err;
	if (ctx2_passed != NULL)
		ctx2=ctx2_passed;
	else
		if ((ctx2=BN_CTX_new()) == NULL) goto err;
		if ((ctx=BN_CTX_new()) == NULL)
			goto err;
	a1 = &(ctx->bn[ctx->tos++]);
	a1_odd = &(ctx->bn[ctx->tos++]);
	check = &(ctx->bn[ctx->tos++]);;

	if ((mont=BN_MONT_CTX_new()) == NULL) goto err;
	/* compute a1 := a - 1 */
	if (!BN_copy(a1, a))
		goto err;
	if (!BN_sub_word(a1, 1))
		goto err;
	if (BN_is_zero(a1))
		{
		ret = 0;
		goto err;
		}

	check= &(ctx->bn[ctx->tos++]);
	/* write  a1  as  a1_odd * 2^k */
	k = 1;
	while (!BN_is_bit_set(a1, k))
		k++;
	if (!BN_rshift(a1_odd, a1, k))
		goto err;

	/* Setup the montgomery structure */
	if (!BN_MONT_CTX_set(mont,a,ctx2)) goto err;
	/* Montgomery setup for computations mod a */
	mont = BN_MONT_CTX_new();
	if (mont == NULL)
		goto err;
	if (!BN_MONT_CTX_set(mont, a, ctx))
		goto err;
	
	for (i = 0; i < checks; i++)
		{
		if (!BN_pseudo_rand(check,BN_num_bits(a),0,0)) goto err;
		if (BN_cmp(check, a) >= 0)
			BN_sub(check, check, a);
		if (BN_is_zero(check)) BN_one(check);
		j=witness(check,a,ctx,ctx2,mont);
		if (!BN_pseudo_rand(check, BN_num_bits(a1), 0, 0))
			goto err;
		if (BN_cmp(check, a1) >= 0)
			if (!BN_sub(check, check, a1))
				goto err;
		if (!BN_add_word(check, 1))
			goto err;
		/* now 1 <= check < a */

		j = witness(check, a, a1, a1_odd, k, ctx, mont);
		if (j == -1) goto err;
		if (j)
			{
@@ -216,84 +244,38 @@ int BN_is_prime_fasttest(BIGNUM *a, int checks,
		}
	ret=1;
err:
	ctx->tos--;
	if ((ctx_passed == NULL) && (ctx != NULL))
	if (ctx_passed != NULL)
		ctx_passed->tos -= 3; /* a1, a1_odd, check */
	else if (ctx != NULL)
		BN_CTX_free(ctx);
	if ((ctx2_passed == NULL) && (ctx2 != NULL))
		BN_CTX_free(ctx2);
	if (mont != NULL) BN_MONT_CTX_free(mont);
	if (mont != NULL)
		BN_MONT_CTX_free(mont);

	return(ret);
	}

int BN_is_prime(BIGNUM *a, int checks, void (*callback)(int,int,void *),
	BN_CTX *ctx_passed, void *cb_arg)
	{
	return BN_is_prime_fasttest(a, checks, callback, ctx_passed, NULL, cb_arg, 0);
	}

static int witness(BIGNUM *a, BIGNUM *n, BN_CTX *ctx, BN_CTX *ctx2,
	     BN_MONT_CTX *mont)
static int witness(BIGNUM *w, BIGNUM *a, BIGNUM *a1, BIGNUM *a1_odd, int k,
	BN_CTX *ctx, BN_MONT_CTX *mont)
	{
	int k,i,ret= -1,good;
	BIGNUM *d,*dd,*tmp,*d1,*d2,*n1;
	BIGNUM *mont_one,*mont_n1,*mont_a;

	d1= &(ctx->bn[ctx->tos]);
	d2= &(ctx->bn[ctx->tos+1]);
	n1= &(ctx->bn[ctx->tos+2]);
	ctx->tos+=3;

	mont_one= &(ctx2->bn[ctx2->tos]);
	mont_n1= &(ctx2->bn[ctx2->tos+1]);
	mont_a= &(ctx2->bn[ctx2->tos+2]);
	ctx2->tos+=3;

	d=d1;
	dd=d2;
	if (!BN_one(d)) goto err;
	if (!BN_sub(n1,n,d)) goto err; /* n1=n-1; */
	k=BN_num_bits(n1);

	if (!BN_to_montgomery(mont_one,BN_value_one(),mont,ctx2)) goto err;
	if (!BN_to_montgomery(mont_n1,n1,mont,ctx2)) goto err;
	if (!BN_to_montgomery(mont_a,a,mont,ctx2)) goto err;

	BN_copy(d,mont_one);
	for (i=k-1; i>=0; i--)
	if (!BN_mod_exp_mont(w, w, a1_odd, a, ctx, mont)) /* w := w^a1_odd mod a */
		return -1;
	if (BN_is_one(w))
		return 0; /* probably prime */
	if (BN_cmp(w, a1) == 0)
		return 0; /* w == -1 (mod a),  'a' is probably prime */
	while (--k)
		{
		if (	(BN_cmp(d,mont_one) != 0) &&
			(BN_cmp(d,mont_n1) != 0))
			good=1;
		else
			good=0;

		BN_mod_mul_montgomery(dd,d,d,mont,ctx2);

		if (good && (BN_cmp(dd,mont_one) == 0))
			{
			ret=1;
			goto err;
			}
		if (BN_is_bit_set(n1,i))
			{
			BN_mod_mul_montgomery(d,dd,mont_a,mont,ctx2);
			}
		else
			{
			tmp=d;
			d=dd;
			dd=tmp;
			}
		if (!BN_mod_mul(w, w, w, a, ctx)) /* w := w^2 mod a */
			return -1;
		if (BN_is_one(w))
			return 1; /* 'a' is composite, otherwise a previous 'w' would
			           * have been == -1 (mod 'a') */
		if (BN_cmp(w, a1) == 0)
			return 0; /* w == -1 (mod a), 'a' is probably prime */
		}
	if (BN_cmp(d,mont_one) == 0)
		i=0;
	else	i=1;
	ret=i;
err:
	ctx->tos-=3;
	ctx2->tos-=3;
	return(ret);
	/* If we get here, 'w' is the (a-1)/2-th power of the original 'w',
	 * and it is neither -1 nor +1 -- so 'a' cannot be prime */
	return 1;
	}

static int probable_prime(BIGNUM *rnd, int bits)
@@ -411,76 +393,3 @@ err:
	ctx->tos-=3;
	return(ret);
	}

#if 0

#define RECP_MUL_MOD

static int witness(BIGNUM *a, BIGNUM *n, BN_CTX *ctx,
		   BN_CTX *unused, BN_MONT_CTX *unused2)
	{
	int k,i,ret= -1;
	BIGNUM *d,*dd,*tmp;
	BIGNUM *d1,*d2,*x,*n1;
	BN_RECP_CTX recp;

	d1= &(ctx->bn[ctx->tos]);
	d2= &(ctx->bn[ctx->tos+1]);
	x=  &(ctx->bn[ctx->tos+2]);
	n1= &(ctx->bn[ctx->tos+3]);
	ctx->tos+=4;

	d=d1;
	dd=d2;
	if (!BN_one(d)) goto err;
	if (!BN_sub(n1,n,d)) goto err; /* n1=n-1; */
	k=BN_num_bits(n1);

	/* i=BN_num_bits(n); */
#ifdef RECP_MUL_MOD
	BN_RECP_CTX_init(&recp);
	if (BN_RECP_CTX_set(&recp,n,ctx) <= 0) goto err;
#endif

	for (i=k-1; i>=0; i--)
		{
		if (BN_copy(x,d) == NULL) goto err;
#ifndef RECP_MUL_MOD
		if (!BN_mod_mul(dd,d,d,n,ctx)) goto err;
#else
		if (!BN_mod_mul_reciprocal(dd,d,d,&recp,ctx)) goto err;
#endif
		if (	BN_is_one(dd) &&
			!BN_is_one(x) &&
			(BN_cmp(x,n1) != 0))
			{
			ret=1;
			goto err;
			}
		if (BN_is_bit_set(n1,i))
			{
#ifndef RECP_MUL_MOD
			if (!BN_mod_mul(d,dd,a,n,ctx)) goto err;
#else
			if (!BN_mod_mul_reciprocal(d,dd,a,&recp,ctx)) goto err; 
#endif
			}
		else
			{
			tmp=d;
			d=dd;
			dd=tmp;
			}
		}
	if (BN_is_one(d))
		i=0;
	else	i=1;
	ret=i;
err:
	ctx->tos-=4;
#ifdef RECP_MUL_MOD
	BN_RECP_CTX_free(&recp);
#endif
	return(ret);
	}
#endif
+3 −5
Original line number Diff line number Diff line
@@ -93,7 +93,7 @@ DSA *DSA_generate_parameters(int bits, unsigned char *seed_in, int seed_len,
	int k,n=0,i,b,m=0;
	int counter=0;
	int r=0;
	BN_CTX *ctx=NULL,*ctx2=NULL,*ctx3=NULL,*ctx4=NULL;
	BN_CTX *ctx=NULL,*ctx2=NULL,*ctx3=NULL;
	unsigned int h=2;
	DSA *ret=NULL;

@@ -111,7 +111,6 @@ DSA *DSA_generate_parameters(int bits, unsigned char *seed_in, int seed_len,
	if ((ctx=BN_CTX_new()) == NULL) goto err;
	if ((ctx2=BN_CTX_new()) == NULL) goto err;
	if ((ctx3=BN_CTX_new()) == NULL) goto err;
	if ((ctx4=BN_CTX_new()) == NULL) goto err;
	if ((ret=DSA_new()) == NULL) goto err;

	if ((mont=BN_MONT_CTX_new()) == NULL) goto err;
@@ -167,7 +166,7 @@ DSA *DSA_generate_parameters(int bits, unsigned char *seed_in, int seed_len,
			if (!BN_bin2bn(md,SHA_DIGEST_LENGTH,q)) goto err;

			/* step 4 */
			r = BN_is_prime_fasttest(q, DSS_prime_checks, callback, ctx3, ctx4, cb_arg, seed_is_random);
			r = BN_is_prime_fasttest(q, DSS_prime_checks, callback, ctx3, cb_arg, seed_is_random);
			if (r > 0)
					break;
			if (r != 0)
@@ -228,7 +227,7 @@ DSA *DSA_generate_parameters(int bits, unsigned char *seed_in, int seed_len,
			if (BN_cmp(p,test) >= 0)
				{
				/* step 11 */
				r = BN_is_prime_fasttest(p, DSS_prime_checks, callback, ctx3, ctx4, cb_arg, 1);
				r = BN_is_prime_fasttest(p, DSS_prime_checks, callback, ctx3, cb_arg, 1);
				if (r > 0)
						goto end; /* found it */
				if (r != 0)
@@ -283,7 +282,6 @@ err:
	if (ctx != NULL) BN_CTX_free(ctx);
	if (ctx2 != NULL) BN_CTX_free(ctx2);
	if (ctx3 != NULL) BN_CTX_free(ctx3);
	if (ctx4 != NULL) BN_CTX_free(ctx4);
	if (mont != NULL) BN_MONT_CTX_free(mont);
	return(ok?ret:NULL);
	}
+2 −6
Original line number Diff line number Diff line
@@ -15,8 +15,7 @@ BN_generate_prime, BN_is_prime, BN_is_prime_fasttest - Generate primes and test
     void *), BN_CTX *ctx, void *cb_arg);

 int BN_is_prime_fasttest(BIGNUM *a, int checks, void (*callback)(int,
     int, void *), BN_CTX *ctx, BN_CTX *ctx2, void *cb_arg,
     int do_trial_division);
     int, void *), BN_CTX *ctx, void *cb_arg, int do_trial_division);

=head1 DESCRIPTION

@@ -76,10 +75,7 @@ yields a false positive rate of at most 2^-80 for random input.
If B<callback> is not B<NULL>, B<callback(1, j, cb_arg)> is called
after the j-th iteration (j = 0, 1, ...). B<ctx> is a
pre-allocated B<BN_CTX> (to save the overhead of allocating and
freeing the structure in a loop), or B<NULL>. For
BN_is_prime_fasttest(), B<ctx2> is a second pre-allocated B<BN_CTX> or
B<NULL> (lacking this parameter, BN_is_prime() always has to allocate
an additional B<CN_CTX>).
freeing the structure in a loop), or B<NULL>.

=head1 RETURN VALUES