There's a slight possibility that a is 0 in BN_sub_word(), and might

[openssl.git] / crypto / bn / bn_word.c

diff --git a/crypto/bn/bn_word.c b/crypto/bn/bn_word.c
index 73157a7d43fda6711572abe34dd28a11b0855a42..f3bdde969cc376a9344b9d58c6d8c6a97766bcd6 100644 (file)
--- a/crypto/bn/bn_word.c
+++ b/crypto/bn/bn_word.c
@@ -115,7 +115,7 @@ int BN_add_word(BIGNUM *a, BN_ULONG w)
                a->neg=0;
                i=BN_sub_word(a,w);
                if (!BN_is_zero(a))
-                       a->neg=1;
+                       a->neg=!(a->neg);
                return(i);
                }
        w&=BN_MASK2;
@@ -140,7 +140,7 @@ int BN_sub_word(BIGNUM *a, BN_ULONG w)
        {
        int i;
 
-       if (a->neg)
+       if (BN_is_zero(a) || a->neg)
                {
                a->neg=0;
                i=BN_add_word(a,w);