OpenSSL::BN#==

static VALUE
ossl_bn_eq(VALUE self, VALUE other)
{
    BIGNUM *bn1, *bn2;

    GetBN(self, bn1);
    other = try_convert_to_bn(other);
    if (NIL_P(other))
        return Qfalse;
    GetBN(other, bn2);

    if (!BN_cmp(bn1, bn2)) {
        return Qtrue;
    }
    return Qfalse;
}