OpenSSL::PKey::EC#public_key

static VALUE ossl_ec_key_get_public_key(VALUE self)
{
    OSSL_3_const EC_KEY *ec;
    const EC_POINT *point;

    GetEC(self, ec);
    if ((point = EC_KEY_get0_public_key(ec)) == NULL)
        return Qnil;

    return ec_point_new(point, EC_KEY_get0_group(ec));
}