clio/src/web/SslHttpSession.hpp

#pragma once

#include "data/LedgerCacheInterface.hpp"
#include "util/Taggable.hpp"
#include "web/AdminVerificationStrategy.hpp"
#include "web/ProxyIpResolver.hpp"
#include "web/SslWsSession.hpp"
#include "web/dosguard/DOSGuardInterface.hpp"
#include "web/impl/HttpBase.hpp"
#include "web/interface/Concepts.hpp"
#include "web/interface/ConnectionBase.hpp"

#include <boost/asio/ip/tcp.hpp>
#include <boost/asio/ssl/context.hpp>
#include <boost/asio/ssl/stream_base.hpp>
#include <boost/beast/core/error.hpp>
#include <boost/beast/core/flat_buffer.hpp>
#include <boost/beast/core/stream_traits.hpp>
#include <boost/beast/core/tcp_stream.hpp>
#include <boost/beast/ssl/ssl_stream.hpp>

#include <chrono>
#include <cstddef>
#include <cstdint>
#include <functional>
#include <memory>
#include <string>
#include <utility>

namespace web {

using tcp = boost::asio::ip::tcp;

/**
 * @brief Represents a HTTPS connection established by a client.
 *
 * It will handle the upgrade to secure websocket, pass the ownership of the socket to the upgrade
 * session. Otherwise, it will pass control to the base class.
 *
 * @tparam HandlerType The type of the server handler to use
 */
template <SomeServerHandler HandlerType>
class SslHttpSession : public impl::HttpBase<SslHttpSession, HandlerType>,
                       public std::enable_shared_from_this<SslHttpSession<HandlerType>> {
    boost::asio::ssl::stream<boost::beast::tcp_stream> stream_;
    std::reference_wrapper<util::TagDecoratorFactory const> tagFactory_;
    std::uint32_t maxWsSendingQueueSize_;

public:
    /**
     * @brief Create a new SSL session.
     *
     * @param socket The socket. Ownership is transferred to HttpSession
     * @param ip Client's IP address
     * @param adminVerification The admin verification strategy to use
     * @param proxyIpResolver The client ip resolver if a request was forwarded by a proxy
     * @param ctx The SSL context
     * @param tagFactory A factory that is used to generate tags to track requests and sessions
     * @param dosGuard The denial of service guard to use
     * @param handler The server handler to use
     * @param cache The ledger cache to use
     * @param buffer Buffer with initial data received from the peer
     * @param maxWsSendingQueueSize The maximum size of the sending queue for websocket
     */
    explicit SslHttpSession(
        tcp::socket&& socket,
        std::string const& ip,
        std::shared_ptr<AdminVerificationStrategy> const& adminVerification,
        std::shared_ptr<ProxyIpResolver> proxyIpResolver,
        boost::asio::ssl::context& ctx,
        std::reference_wrapper<util::TagDecoratorFactory const> tagFactory,
        std::reference_wrapper<dosguard::DOSGuardInterface> dosGuard,
        std::shared_ptr<HandlerType> const& handler,
        std::reference_wrapper<data::LedgerCacheInterface const> cache,
        boost::beast::flat_buffer buffer,
        std::uint32_t maxWsSendingQueueSize
    )
        : impl::HttpBase<SslHttpSession, HandlerType>(
              ip,
              tagFactory,
              adminVerification,
              std::move(proxyIpResolver),
              dosGuard,
              handler,
              cache,
              std::move(buffer)
          )
        , stream_(std::move(socket), ctx)
        , tagFactory_(tagFactory)
        , maxWsSendingQueueSize_(maxWsSendingQueueSize)
    {
    }

    ~SslHttpSession() override = default;

    /** @return The SSL stream. */
    boost::asio::ssl::stream<boost::beast::tcp_stream>&
    stream()
    {
        return stream_;
    }

    /** @brief Initiates the handshake. */
    void
    run()
    {
        auto self = this->shared_from_this();
        boost::asio::dispatch(stream_.get_executor(), [self]() {
            // Set the timeout.
            boost::beast::get_lowest_layer(self->stream()).expires_after(std::chrono::seconds(30));

            // Perform the SSL handshake
            // Note, this is the buffered version of the handshake.
            self->stream_.async_handshake(
                boost::asio::ssl::stream_base::server,
                self->buffer_.data(),
                boost::beast::bind_front_handler(&SslHttpSession<HandlerType>::onHandshake, self)
            );
        });
    }

    /**
     * @brief Handles the handshake.
     *
     * @param ec Error code if any
     * @param bytesUsed The total amount of data read from the stream
     */
    void
    onHandshake(boost::beast::error_code ec, std::size_t bytesUsed)
    {
        if (ec)
            return this->httpFail(ec, "handshake");

        this->buffer_.consume(bytesUsed);
        this->doRead();
    }

    /** @brief Closes the underlying connection. */
    void
    doClose()
    {
        boost::beast::get_lowest_layer(stream_).expires_after(std::chrono::seconds(30));
        stream_.async_shutdown(
            boost::beast::bind_front_handler(&SslHttpSession::onShutdown, this->shared_from_this())
        );
    }

    /**
     * @brief Handles a connection shutdown.
     *
     * @param ec Error code if any
     */
    void
    onShutdown(boost::beast::error_code ec)
    {
        if (ec)
            return this->httpFail(ec, "shutdown");
        // At this point the connection is closed gracefully
    }

    /** @brief Upgrades connection to secure websocket. */
    void
    upgrade()
    {
        std::make_shared<SslWsUpgrader<HandlerType>>(
            std::move(stream_),
            this->clientIp_,
            tagFactory_,
            this->dosGuard_,
            this->handler_,
            std::move(this->buffer_),
            std::move(this->req_),
            ConnectionBase::isAdmin(),
            maxWsSendingQueueSize_
        )
            ->run();
    }
};
}  // namespace web