EC_GROUP_get_cofactor
if (!EC_GROUP_get_cofactor(group, x, NULL)) {
int EC_GROUP_get_cofactor(const EC_GROUP *group, BIGNUM *cofactor,
|| !TEST_true(EC_GROUP_get_cofactor(group, group_cofactor, NULL))
|| !TEST_true(EC_GROUP_get_cofactor(group, group_cofactor, NULL))
|| !TEST_true(EC_GROUP_get_cofactor(g1, g1_cf, ctx))
|| !TEST_true(EC_GROUP_get_cofactor(g2, g2_cf, ctx))
|| !TEST_true(EC_GROUP_get_cofactor(g2, g2_cf, ctx))