Commit aff0825c authored by Bodo Möller's avatar Bodo Möller
Browse files

Tolerate negative numbers in BN_is_prime.

parent e74231ed

crypto/bn/bn.h

+3 −2
Original line number Diff line number Diff line
@@ -404,9 +404,10 @@ int BN_gcd(BIGNUM *r,BIGNUM *in_a,BIGNUM *in_b,BN_CTX *ctx); 
BIGNUM *BN_mod_inverse(BIGNUM *ret,BIGNUM *a, const BIGNUM *n,BN_CTX *ctx);

BIGNUM *BN_generate_prime(BIGNUM *ret,int bits,int safe,BIGNUM *add,

		BIGNUM *rem,void (*callback)(int,int,void *),void *cb_arg);

int	BN_is_prime(BIGNUM *p,int nchecks,void (*callback)(int,int,void *),

int	BN_is_prime(const BIGNUM *p,int nchecks,

		void (*callback)(int,int,void *),

		BN_CTX *ctx,void *cb_arg);

int	BN_is_prime_fasttest(BIGNUM *p,int nchecks,

int	BN_is_prime_fasttest(const BIGNUM *p,int nchecks,

		void (*callback)(int,int,void *),BN_CTX *ctx,void *cb_arg,

		int do_trial_division);

void	ERR_load_BN_strings(void );

crypto/bn/bn_lcl.h

+1 −1
Original line number Diff line number Diff line
@@ -203,7 +203,7 @@ extern "C" { 
	BN_ULLONG t; \

	t=(BN_ULLONG)(a)*(a); \

	(r0)=Lw(t); \

	(r1)=Hw(t); ]

	(r1)=Hw(t); \

	}



#elif defined(BN_UMULT_HIGH)

crypto/bn/bn_prime.c

+34 −23
Original line number Diff line number Diff line
@@ -154,13 +154,13 @@ err: 
	return(found ? rnd : NULL);

	}



int BN_is_prime(BIGNUM *a, int checks, void (*callback)(int,int,void *),

int BN_is_prime(const 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,

int BN_is_prime_fasttest(const BIGNUM *a, int checks,

		void (*callback)(int,int,void *),

		BN_CTX *ctx_passed, void *cb_arg,

		int do_trial_division)
@@ -168,15 +168,13 @@ int BN_is_prime_fasttest(BIGNUM *a, int checks, 
	int i, j, ret = -1;

	int k;

	BN_CTX *ctx = NULL;

	BIGNUM *a1, *a1_odd, *check; /* taken from ctx */

	BIGNUM *A1, *A1_odd, *check; /* taken from ctx */

	BN_MONT_CTX *mont = NULL;

	BIGNUM *A;



	if (checks == BN_prime_checks)

		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);
@@ -193,47 +191,56 @@ int BN_is_prime_fasttest(BIGNUM *a, int checks, 
	else

		if ((ctx=BN_CTX_new()) == NULL)

			goto err;

	a1 = &(ctx->bn[ctx->tos++]);

	a1_odd = &(ctx->bn[ctx->tos++]);

	/* A := abs(a) */

	if (a->neg)

		{

		A = &(ctx->bn[ctx->tos++]);

		BN_copy(A, a);

		A->neg = 0;

		}

	else

		A = a;

	A1 = &(ctx->bn[ctx->tos++]);

	A1_odd = &(ctx->bn[ctx->tos++]);

	check = &(ctx->bn[ctx->tos++]);;



	/* compute a1 := a - 1 */

	if (!BN_copy(a1, a))

	/* compute A1 := A - 1 */

	if (!BN_copy(A1, A))

		goto err;

	if (!BN_sub_word(a1, 1))

	if (!BN_sub_word(A1, 1))

		goto err;

	if (BN_is_zero(a1))

	if (BN_is_zero(A1))

		{

		ret = 0;

		goto err;

		}



	/* write  a1  as  a1_odd * 2^k */

	/* write  A1  as  A1_odd * 2^k */

	k = 1;

	while (!BN_is_bit_set(a1, k))

	while (!BN_is_bit_set(A1, k))

		k++;

	if (!BN_rshift(a1_odd, a1, k))

	if (!BN_rshift(A1_odd, A1, k))

		goto err;



	/* Montgomery setup for computations mod a */

	/* Montgomery setup for computations mod A */

	mont = BN_MONT_CTX_new();

	if (mont == NULL)

		goto err;

	if (!BN_MONT_CTX_set(mont, a, ctx))

	if (!BN_MONT_CTX_set(mont, A, ctx))

		goto err;

	

	for (i = 0; i < checks; i++)

		{

		if (!BN_pseudo_rand(check, BN_num_bits(a1), 0, 0))

		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))

		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 */

		/* now 1 <= check < A */



		j = witness(check, a, a1, a1_odd, k, ctx, mont);

		j = witness(check, A, A1, A1_odd, k, ctx, mont);

		if (j == -1) goto err;

		if (j)

			{
@@ -245,7 +252,11 @@ int BN_is_prime_fasttest(BIGNUM *a, int checks, 
	ret=1;

err:

	if (ctx_passed != NULL)

		ctx_passed->tos -= 3; /* a1, a1_odd, check */

		{

		ctx_passed->tos -= 3; /* A1, A1_odd, check */

		if (a != A)

			--ctx_passed->tos; /* A */

		}

	else if (ctx != NULL)

		BN_CTX_free(ctx);

	if (mont != NULL)

crypto/dsa/dsa_gen.c

+4 −2
Original line number Diff line number Diff line
@@ -167,6 +167,8 @@ DSA *DSA_generate_parameters(int bits, unsigned char *seed_in, int seed_len, 


			/* step 4 */

			r = BN_is_prime_fasttest(q, DSS_prime_checks, callback, ctx3, cb_arg, seed_is_random);

			if (ctx3->tos)

				goto err;

			if (r > 0)

				break;

			if (r != 0)

doc/crypto/BN_generate_prime.pod

+4 −3
Original line number Diff line number Diff line
@@ -11,11 +11,12 @@ BN_generate_prime, BN_is_prime, BN_is_prime_fasttest - Generate primes and test 
 BIGNUM *BN_generate_prime(BIGNUM *ret, int num, int safe, BIGNUM *add,

     BIGNUM *rem, void (*callback)(int, int, void *), void *cb_arg);



 int BN_is_prime(BIGNUM *a, int checks, void (*callback)(int, int, 

 int BN_is_prime(const BIGNUM *a, int checks, void (*callback)(int, int, 

     void *), BN_CTX *ctx, void *cb_arg);



 int BN_is_prime_fasttest(BIGNUM *a, int checks, void (*callback)(int,

     int, void *), BN_CTX *ctx, void *cb_arg, int do_trial_division);

 int BN_is_prime_fasttest(const BIGNUM *a, int checks,

     void (*callback)(int, int, void *), BN_CTX *ctx, void *cb_arg,

     int do_trial_division);



=head1 DESCRIPTION