modular arithmetics

"make update"

1 files changed, 29 insertions, 0 deletions

diff --git a/crypto/bn/bn_lib.c b/crypto/bn/bn_lib.c
index 130a9e2db4..0e161d173e 100644
--- a/crypto/bn/bn_lib.c
+++ b/crypto/bn/bn_lib.c
@@ -561,6 +561,35 @@ BIGNUM *BN_copy(BIGNUM *a, const BIGNUM *b)
 	return(a);
 	}
 
+void BN_swap(BIGNUM *a, BIGNUM *b)
+	{
+	int flags_old_a, flags_old_b;
+	BN_ULONG *tmp_d;
+	int tmp_top, tmp_dmax, tmp_neg;
+	
+	flags_old_a = a->flags;
+	flags_old_b = b->flags;
+
+	tmp_d = a->d;
+	tmp_top = a->top;
+	tmp_dmax = a->dmax;
+	tmp_neg = a->neg;
+	
+	a->d = b->d;
+	a->top = b->top;
+	a->dmax = b->dmax;
+	a->neg = b->neg;
+	
+	b->d = tmp_d;
+	b->top = tmp_top;
+	b->dmax = tmp_dmax;
+	b->neg = tmp_neg;
+	
+	a->flags = (flags_old_a & BN_FLG_MALLOCED) | (flags_old_b & BN_FLG_STATIC_DATA);
+	b->flags = (flags_old_b & BN_FLG_MALLOCED) | (flags_old_a & BN_FLG_STATIC_DATA);
+	}
+
+
 void BN_clear(BIGNUM *a)
 	{
 	if (a->d != NULL)