include/diffie-hellman.h

/*
 *  Copyright (C) 2004-2023 Savoir-faire Linux Inc.
 *
 *  This program is free software: you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License as published by
 *  the Free Software Foundation, either version 3 of the License, or
 *  (at your option) any later version.
 *
 *  This program is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
 *  GNU General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public License
 *  along with this program. If not, see <https://www.gnu.org/licenses/>.
 */
#pragma once

#include <gnutls/gnutls.h>

#include <vector>
#include <memory>
#include <cstdint>
#include <string>
#include <filesystem>

namespace dhtnet {
namespace tls {

class DhParams
{
public:
    DhParams() = default;
    DhParams(DhParams&&) = default;
    DhParams(const DhParams& other) { *this = other; }

    DhParams& operator=(DhParams&& other) = default;
    DhParams& operator=(const DhParams& other);

    /// \brief Construct by taking ownership of given gnutls DH params
    ///
    /// User should not call gnutls_dh_params_deinit on given \a raw_params.
    /// The object is stolen and its live is manager by our object.
    explicit DhParams(gnutls_dh_params_t p)
        : params_ {p, gnutls_dh_params_deinit}
    {}

    /** Deserialize DER or PEM encoded DH-params */
    DhParams(const std::vector<uint8_t>& data);

    gnutls_dh_params_t get() { return params_.get(); }
    gnutls_dh_params_t get() const { return params_.get(); }

    explicit inline operator bool() const { return bool(params_); }

    /** Serialize data in PEM format */
    std::vector<uint8_t> serialize() const;

    static DhParams generate();

    static DhParams loadDhParams(const std::filesystem::path& path);

private:
    std::unique_ptr<gnutls_dh_params_int, decltype(gnutls_dh_params_deinit)*>
        params_ {nullptr, gnutls_dh_params_deinit};
};

} // namespace tls
} // namespace dhtnet