Don't let top go below zero!
authorBen Laurie <ben@openssl.org>
Sat, 1 Jul 2000 16:30:27 +0000 (16:30 +0000)
committerBen Laurie <ben@openssl.org>
Sat, 1 Jul 2000 16:30:27 +0000 (16:30 +0000)
crypto/bn/bn_mont.c

index e5fbcd6..6a54e8f 100644 (file)
@@ -90,7 +90,7 @@ int BN_mod_mul_montgomery(BIGNUM *r, BIGNUM *a, BIGNUM *b,
                bn_wexpand(tmp2,a->top*4);
                bn_sqr_recursive(tmp->d,a->d,a->top,tmp2->d);
                tmp->top=a->top*2;
-               if (tmp->d[tmp->top-1] == 0)
+               if (tmp->top > 0 && tmp->d[tmp->top-1] == 0)
                        tmp->top--;
 #else
                if (!BN_sqr(tmp,a,ctx)) goto err;