X-Git-Url: https://git.librecmc.org/?a=blobdiff_plain;f=crypto%2Fbn%2Fbn_word.c;h=ee7b87c45ccd38839db6261ed81c2d87b9e881b5;hb=9b4eab501a52c8bdc19a8a002e1f9d4d7ad6f4c4;hp=1bcb37e29222f76dce1baefd9d1bf949389e725e;hpb=cf9056cfda3976fc53a630f9965b68569d656e27;p=oweals%2Fopenssl.git

diff --git a/crypto/bn/bn_word.c b/crypto/bn/bn_word.c
index 1bcb37e292..ee7b87c45c 100644
--- a/crypto/bn/bn_word.c
+++ b/crypto/bn/bn_word.c
@@ -69,6 +69,9 @@ BN_ULONG BN_mod_word(const BIGNUM *a, BN_ULONG w)
 #endif
 	int i;
 
+	if (w == 0)
+		return (BN_ULONG)-1;
+
 	bn_check_top(a);
 	w&=BN_MASK2;
 	for (i=a->top-1; i>=0; i--)
@@ -94,7 +97,7 @@ BN_ULONG BN_div_word(BIGNUM *a, BN_ULONG w)
 
 	if (!w)
 		/* actually this an error (division by zero) */
-		return 0;
+		return (BN_ULONG)-1;
 	if (a->top == 0)
 		return 0;
 
@@ -102,7 +105,7 @@ BN_ULONG BN_div_word(BIGNUM *a, BN_ULONG w)
 	j = BN_BITS2 - BN_num_bits_word(w);
 	w <<= j;
 	if (!BN_lshift(a, a, j))
-		return 0;
+		return (BN_ULONG)-1;
 
 	for (i=a->top-1; i>=0; i--)
 		{
@@ -175,7 +178,13 @@ int BN_sub_word(BIGNUM *a, BN_ULONG w)
 	/* degenerate case: w is zero */
 	if (!w) return 1;
 	/* degenerate case: a is zero */
-	if(BN_is_zero(a)) return BN_set_word(a,w);
+	if(BN_is_zero(a))
+		{
+		i = BN_set_word(a,w);
+		if (i != 0)
+			BN_set_negative(a, 1);
+		return i;
+		}
 	/* handle 'a' when negative */
 	if (a->neg)
 		{