Commit 879bd6e3 authored by Dr. Stephen Henson's avatar Dr. Stephen Henson
Browse files

Internal version of BN_mod_inverse allowing checking of no-inverse without 

need to inspect error queue.
parent 6f1a3a31

crypto/bn/bn_blind.c

+3 −4
Original line number Diff line number Diff line
@@ -331,12 +331,12 @@ BN_BLINDING *BN_BLINDING_create_param(BN_BLINDING *b, 
		ret->m_ctx = m_ctx;



	do {

		int rv;

		if (!BN_rand_range(ret->A, ret->mod)) goto err;

		if (BN_mod_inverse(ret->Ai, ret->A, ret->mod, ctx) == NULL)

		if (!int_bn_mod_inverse(ret->Ai, ret->A, ret->mod, ctx, &rv))

			{

			/* this should almost never happen for good RSA keys */

			unsigned long error = ERR_peek_last_error();

			if (ERR_GET_REASON(error) == BN_R_NO_INVERSE)

			if (rv)

				{

				if (retry_counter-- == 0)

				{
@@ -344,7 +344,6 @@ BN_BLINDING *BN_BLINDING_create_param(BN_BLINDING *b, 
						BN_R_TOO_MANY_ITERATIONS);

					goto err;

				}

				ERR_clear_error();

				}

			else

				goto err;

crypto/bn/bn_gcd.c

+17 −1
Original line number Diff line number Diff line
@@ -205,13 +205,28 @@ err: 
/* solves ax == 1 (mod n) */

static BIGNUM *BN_mod_inverse_no_branch(BIGNUM *in,

        const BIGNUM *a, const BIGNUM *n, BN_CTX *ctx);



BIGNUM *BN_mod_inverse(BIGNUM *in,

	const BIGNUM *a, const BIGNUM *n, BN_CTX *ctx)

	{

	BIGNUM *rv;

	int noinv;

	rv = int_bn_mod_inverse(in, a, n, ctx, &noinv);

	if (noinv)

		BNerr(BN_F_BN_MOD_INVERSE,BN_R_NO_INVERSE);

	return rv;

	}



BIGNUM *int_bn_mod_inverse(BIGNUM *in,

	const BIGNUM *a, const BIGNUM *n, BN_CTX *ctx, int *pnoinv)

	{

	BIGNUM *A,*B,*X,*Y,*M,*D,*T,*R=NULL;

	BIGNUM *ret=NULL;

	int sign;



	if (pnoinv)

		*pnoinv = 0;



	if ((BN_get_flags(a, BN_FLG_CONSTTIME) != 0) || (BN_get_flags(n, BN_FLG_CONSTTIME) != 0))

		{

		return BN_mod_inverse_no_branch(in, a, n, ctx);
@@ -488,7 +503,8 @@ BIGNUM *BN_mod_inverse(BIGNUM *in, 
		}

	else

		{

		BNerr(BN_F_BN_MOD_INVERSE,BN_R_NO_INVERSE);

		if (pnoinv)

			*pnoinv = 1;

		goto err;

		}

	ret=R;

crypto/bn/bn_lcl.h

+3 −0
Original line number Diff line number Diff line
@@ -497,6 +497,9 @@ BN_ULONG bn_sub_part_words(BN_ULONG *r, const BN_ULONG *a, const BN_ULONG *b, 
	int cl, int dl);

int bn_mul_mont(BN_ULONG *rp, const BN_ULONG *ap, const BN_ULONG *bp, const BN_ULONG *np,const BN_ULONG *n0, int num);



BIGNUM *int_bn_mod_inverse(BIGNUM *in,

	const BIGNUM *a, const BIGNUM *n, BN_CTX *ctx, int *noinv);



#ifdef  __cplusplus

}

#endif