BN_bntest_rand generates a single-word zero BIGNUM with quite a large probability.
A zero BIGNUM in turn will end up having a NULL |d|-buffer, which we shouldn't dereference without checking.
Reviewed-by: Richard Levitte <levitte@openssl.org>
do {
BN_bntest_rand(a, 512, -1, 0);
BN_bntest_rand(b, BN_BITS2, -1, 0);
do {
BN_bntest_rand(a, 512, -1, 0);
BN_bntest_rand(b, BN_BITS2, -1, 0);
- s = b->d[0];
- } while (!s);
+ } while (BN_is_zero(b));
BN_copy(b, a);
r = BN_div_word(b, s);
BN_copy(b, a);
r = BN_div_word(b, s);