path: root/https.cpp

#include "https.h"

#include "config.h"
#include "file.h"
#include "server.h"
#include "response.h"

#include <openssl/ssl.h>

#include <boost/asio/buffer.hpp>
#include <boost/beast/core.hpp>
#include <boost/beast/http.hpp>
#include <boost/beast/version.hpp>
#include <boost/beast/ssl.hpp>
#include <boost/asio/dispatch.hpp>
#include <boost/asio/ssl/context.hpp>
#include <boost/asio/strand.hpp>
#include <boost/config.hpp>

#include <algorithm>
#include <cstddef>
#include <cstdlib>
#include <functional>
#include <iostream>
#include <memory>
#include <string>
#include <thread>
#include <vector>

namespace beast = boost::beast;         // from <boost/beast.hpp>
namespace http = beast::http;           // from <boost/beast/http.hpp>
namespace net = boost::asio;            // from <boost/asio.hpp>
namespace ssl = boost::asio::ssl;       // from <boost/asio/ssl.hpp>
using tcp = boost::asio::ip::tcp;       // from <boost/asio/ip/tcp.hpp>

namespace {

// This function produces an HTTP response for the given
// request. The type of the response object depends on the
// contents of the request, so the interface requires the
// caller to pass a generic lambda for receiving the response.
template<class Send>
void
handle_request(
    ::Server& server,
    request_type&& req,
    Send&& send)
{
    return send(std::move(generate_response(req, server)));
}

//------------------------------------------------------------------------------

// Report a failure
void
fail(beast::error_code ec, char const* what)
{
    // ssl::error::stream_truncated, also known as an SSL "short read",
    // indicates the peer closed the connection without performing the
    // required closing handshake (for example, Google does this to
    // improve performance). Generally this can be a security issue,
    // but if your communication protocol is self-terminated (as
    // it is with both HTTP and WebSocket) then you may simply
    // ignore the lack of close_notify.
    //
    // https://github.com/boostorg/beast/issues/38
    //
    // https://security.stackexchange.com/questions/91435/how-to-handle-a-malicious-ssl-tls-shutdown
    //
    // When a short read would cut off the end of an HTTP message,
    // Beast returns the error beast::http::error::partial_message.
    // Therefore, if we see a short read here, it has occurred
    // after the message has been completed, so it is safe to ignore it.

    if(ec == net::ssl::error::stream_truncated)
        return;

    std::cerr << what << ": " << ec.message() << "\n";
}

// Handles an HTTP server connection
class session : public std::enable_shared_from_this<session>
{
    // This is the C++11 equivalent of a generic lambda.
    // The function object is used to send an HTTP message.
    struct send_lambda
    {
        session& self_;

        explicit
        send_lambda(session& self)
            : self_(self)
        {
        }

        template<bool isRequest, class Body, class Fields>
        void
        operator()(http::message<isRequest, Body, Fields>&& msg) const
        {
            // The lifetime of the message has to extend
            // for the duration of the async operation so
            // we use a shared_ptr to manage it.
            auto sp = std::make_shared<
                http::message<isRequest, Body, Fields>>(std::move(msg));

            // Store a type-erased version of the shared
            // pointer in the class to keep it alive.
            self_.res_ = sp;

            // Write the response
            http::async_write(
                self_.stream_,
                *sp,
                beast::bind_front_handler(
                    &session::on_write,
                    self_.shared_from_this(),
                    sp->need_eof()));
        }
    };

    beast::ssl_stream<beast::tcp_stream> stream_;
    beast::flat_buffer buffer_;
    Server& m_server;
    http::request<http::string_body> req_;
    std::shared_ptr<void> res_;
    send_lambda lambda_;

public:
    // Take ownership of the socket
    explicit
    session(
        tcp::socket&& socket,
        ssl::context& ctx,
        Server& server)
        : stream_(std::move(socket), ctx)
        , m_server(server)
        , lambda_(*this)
    {
    }

    // Start the asynchronous operation
    void
    run()
    {
        // We need to be executing within a strand to perform async operations
        // on the I/O objects in this session.
        net::dispatch(
            stream_.get_executor(),
            beast::bind_front_handler(
                &session::on_run,
                shared_from_this()));
    }

    void
    on_run()
    {
        // Set the timeout.
        beast::get_lowest_layer(stream_).expires_after(
            std::chrono::seconds(30));

        // Perform the SSL handshake
        stream_.async_handshake(
            ssl::stream_base::server,
            beast::bind_front_handler(
                &session::on_handshake,
                shared_from_this()));
    }

    void
    on_handshake(beast::error_code ec)
    {
        if(ec)
            return fail(ec, "handshake");

        do_read();
    }

    void
    do_read()
    {
        // Make the request empty before reading,
        // otherwise the operation behavior is undefined.
        req_ = {};

        // Set the timeout.
        beast::get_lowest_layer(stream_).expires_after(std::chrono::seconds(30));

        // Read a request
        http::async_read(stream_, buffer_, req_,
            beast::bind_front_handler(
                &session::on_read,
                shared_from_this()));
    }

    void
    on_read(
        beast::error_code ec,
        std::size_t bytes_transferred)
    {
        boost::ignore_unused(bytes_transferred);

        // This means they closed the connection
        if(ec == http::error::end_of_stream)
            return do_close();

        if(ec)
            return fail(ec, "read");

        // Send the response
        handle_request(m_server, std::move(req_), lambda_);
    }

    void
    on_write(
        bool close,
        beast::error_code ec,
        std::size_t bytes_transferred)
    {
        boost::ignore_unused(bytes_transferred);

        if(ec)
            return fail(ec, "write");

        if(close)
        {
            // This means we should close the connection, usually because
            // the response indicated the "Connection: close" semantic.
            return do_close();
        }

        // We're done with the response so delete it
        res_ = nullptr;

        // Read another request
        do_read();
    }

    void
    do_close()
    {
        // Set the timeout.
        beast::get_lowest_layer(stream_).expires_after(std::chrono::seconds(30));

        // Perform the SSL shutdown
        stream_.async_shutdown(
            beast::bind_front_handler(
                &session::on_shutdown,
                shared_from_this()));
    }

    void
    on_shutdown(beast::error_code ec)
    {
        if(ec)
            return fail(ec, "shutdown");

        // At this point the connection is closed gracefully
    }
};

//------------------------------------------------------------------------------

// Accepts incoming connections and launches the sessions
class listener : public std::enable_shared_from_this<listener>
{
    net::io_context& ioc_;
    ssl::context& ctx_;
    tcp::acceptor acceptor_;
    ::Server& m_server;

public:
    listener(
        net::io_context& ioc,
        ssl::context& ctx,
        tcp::endpoint endpoint,
        Server& server)
        : ioc_(ioc)
        , ctx_(ctx)
        , acceptor_(ioc)
        , m_server(server)
    {
        beast::error_code ec;

        // Open the acceptor
        acceptor_.open(endpoint.protocol(), ec);
        if(ec)
        {
            fail(ec, "open");
            return;
        }

        // Allow address reuse
        acceptor_.set_option(net::socket_base::reuse_address(true), ec);
        if(ec)
        {
            fail(ec, "set_option");
            return;
        }

        // Bind to the server address
        acceptor_.bind(endpoint, ec);
        if(ec)
        {
            fail(ec, "bind");
            return;
        }

        // Start listening for connections
        acceptor_.listen(
            net::socket_base::max_listen_connections, ec);
        if(ec)
        {
            fail(ec, "listen");
            return;
        }
    }

    // Start accepting incoming connections
    void
    run()
    {
        do_accept();
    }

private:
    void
    do_accept()
    {
        // The new connection gets its own strand
        acceptor_.async_accept(
            net::make_strand(ioc_),
            beast::bind_front_handler(
                &listener::on_accept,
                shared_from_this()));
    }

    void
    on_accept(beast::error_code ec, tcp::socket socket)
    {
        if(ec)
        {
            fail(ec, "accept");
        }
        else
        {
            // Create the session and run it
            std::make_shared<session>(
                std::move(socket),
                ctx_,
                m_server)->run();
        }

        // Accept another connection
        do_accept();
    }
};

/*  Load a signed certificate into the ssl context, and configure
    the context for use with a server.

    For this to work with the browser or operating system, it is
    necessary to import the "Beast Test CA" certificate into
    the local certificate store, browser, or operating system
    depending on your environment Please see the documentation
    accompanying the Beast certificate for more details.
*/
void load_server_certificate(boost::asio::ssl::context& ctx, fs::path cert_path, fs::path key_path)
{
    /*
        The certificate was generated from CMD.EXE on Windows 10 using:

        winpty openssl dhparam -out dh.pem 2048
        winpty openssl req -newkey rsa:2048 -nodes -keyout key.pem -x509 -days 10000 -out cert.pem -subj "//C=US\ST=CA\L=Los Angeles\O=Beast\CN=www.example.com"
    */

    std::string const dh =
        "-----BEGIN DH PARAMETERS-----\n"
        "MIIBCAKCAQEArzQc5mpm0Fs8yahDeySj31JZlwEphUdZ9StM2D8+Fo7TMduGtSi+\n"
        "/HRWVwHcTFAgrxVdm+dl474mOUqqaz4MpzIb6+6OVfWHbQJmXPepZKyu4LgUPvY/\n"
        "4q3/iDMjIS0fLOu/bLuObwU5ccZmDgfhmz1GanRlTQOiYRty3FiOATWZBRh6uv4u\n"
        "tff4A9Bm3V9tLx9S6djq31w31Gl7OQhryodW28kc16t9TvO1BzcV3HjRPwpe701X\n"
        "oEEZdnZWANkkpR/m/pfgdmGPU66S2sXMHgsliViQWpDCYeehrvFRHEdR9NV+XJfC\n"
        "QMUk26jPTIVTLfXmmwU0u8vUkpR7LQKkwwIBAg==\n"
        "-----END DH PARAMETERS-----\n";
    
    ctx.set_password_callback(
        [](std::size_t,
            boost::asio::ssl::context_base::password_purpose)
        {
            return "test";
        });

    ctx.set_options(
        boost::asio::ssl::context::default_workarounds |
        boost::asio::ssl::context::no_sslv2 |
        boost::asio::ssl::context::single_dh_use);

    std::string cert;
    if (cert_path == "") {
     // generate dummy self signed certificate. Will be replaced by real
     // certificate if configured upon respective session
     cert =
      "-----BEGIN CERTIFICATE-----\n"
      "MIIDnTCCAoWgAwIBAgIULkYtO+2Ddeg+qLZ+aDQpmA5b4L0wDQYJKoZIhvcNAQEL\n"
      "BQAwXjELMAkGA1UEBhMCREUxEDAOBgNVBAgMB0JhdmFyaWExDzANBgNVBAcMBk11\n"
      "bmljaDEVMBMGA1UECgwMUmVpY2h3ZWluIElUMRUwEwYDVQQDDAxyZWljaHdlaW4u\n"
      "aXQwHhcNMjAwNDA1MDgwNzIyWhcNNDcwODIyMDgwNzIyWjBeMQswCQYDVQQGEwJE\n"
      "RTEQMA4GA1UECAwHQmF2YXJpYTEPMA0GA1UEBwwGTXVuaWNoMRUwEwYDVQQKDAxS\n"
      "ZWljaHdlaW4gSVQxFTATBgNVBAMMDHJlaWNod2Vpbi5pdDCCASIwDQYJKoZIhvcN\n"
      "AQEBBQADggEPADCCAQoCggEBALJNb0WLbz+xP+YITMMk+eeK/SIOCRFs/9aZIAyK\n"
      "ParGauxa+8d25mlfJTAo6/G0h3sA240JHyNpOzVOogPU+v4dRWyGO0w5vHVD0caB\n"
      "rDb1eEfmLtqfKLLUL9iPDReUh6WAE7qoNDtfoT551uSMIae1cpPUduVTnSkEgw8k\n"
      "NjJSHYT800jSB2R+e7tJG3ErXDM63R3B8RbitZPoWACjpBxDT+Qrj0fBFS4AWw6b\n"
      "z09uitv0RrgI6CW7xRh3UAdRwEBGHiU6HTIthX6LNgez1UL0sfu1iZ22wNmYZP/S\n"
      "sL3b20WtSH9LN2PRJ4q3AGt6RMbmSGr65ljha9xkTFna0Y8CAwEAAaNTMFEwHQYD\n"
      "VR0OBBYEFKd5/MGFZUAUV502vJ/Kcswax8WVMB8GA1UdIwQYMBaAFKd5/MGFZUAU\n"
      "V502vJ/Kcswax8WVMA8GA1UdEwEB/wQFMAMBAf8wDQYJKoZIhvcNAQELBQADggEB\n"
      "AIBS4AfM7wiunQ2UZQQ5A0Un99+BLax9e+h11h/jGeJ+/9maY/E9MK6UG9LXoOv2\n"
      "z32Q7Ta2xKeRu6GC/qupwYJ0Xt3LENOfogsaNCAgxKlAN48LGlRyCTvzWsEMh28j\n"
      "RaelWonh2qQoiryKLVnRwrg8g1Bu4v+V437cIBmeZPxf0spEL9EVqlN+iS8plmel\n"
      "7/F4ULdybKGq39tgicuS7JhnY21ZzOFoq0bWnKBbAeTndmuROdb3pEppxW6pwu0q\n"
      "TFdMrSJE38kiQh2O9IchPQbTZ+Rdj0HE9NxStlrNr5bu6rjikRm50/G3JoXpzYdp\n"
      "AN4ZI2QZ6R6Y+TzDixKecNk=\n"
      "-----END CERTIFICATE-----\n"
      ;
    } else {
     cert = File::getFile(cert_path);
    }

    ctx.use_certificate_chain(
        boost::asio::buffer(cert.data(), cert.size()));

    std::string key;
    if (key_path == "") {
     // generate dummy self signed certificate. Will be replaced by real
     // certificate if configured upon respective session
     key =
      "-----BEGIN PRIVATE KEY-----\n"
      "MIIEvgIBADANBgkqhkiG9w0BAQEFAASCBKgwggSkAgEAAoIBAQCyTW9Fi28/sT/m\n"
      "CEzDJPnniv0iDgkRbP/WmSAMij2qxmrsWvvHduZpXyUwKOvxtId7ANuNCR8jaTs1\n"
      "TqID1Pr+HUVshjtMObx1Q9HGgaw29XhH5i7anyiy1C/Yjw0XlIelgBO6qDQ7X6E+\n"
      "edbkjCGntXKT1HblU50pBIMPJDYyUh2E/NNI0gdkfnu7SRtxK1wzOt0dwfEW4rWT\n"
      "6FgAo6QcQ0/kK49HwRUuAFsOm89Pborb9Ea4COglu8UYd1AHUcBARh4lOh0yLYV+\n"
      "izYHs9VC9LH7tYmdtsDZmGT/0rC929tFrUh/Szdj0SeKtwBrekTG5khq+uZY4Wvc\n"
      "ZExZ2tGPAgMBAAECggEBAK9bJKIa3dCgPB257/TEOtsTgJyrfROcRYkCk9iBZOC9\n"
      "v46wdIrZTwY2wtY4iMPwLoY0c7ijTfJ/nfFxYjmujyK4Gvz+jvcKmWQizP8TrRFo\n"
      "HWFo6o+slFQ8BspO9itIspd7/OtIXgY+qNBO959Sig7sjsEA5eXoc9pRS6vqizq0\n"
      "j4G/UO5Amr/l3ciEJiqMJgZsIVLDKaGlqFTymydSqkB8UHQYWK1kunQxhK4Ldycu\n"
      "hTooQE7tXM0zvoFVV6v1fldV5OFsZk2kPMNtvMO6ZEpOM4rNMlg+vJy8kB1fb3Gs\n"
      "iFE/DCUpZsMSserQMU9/hfrYlndgsFD5Sr1EVGEebhECgYEA1gc9qx+ugdhYTY5j\n"
      "tJDXjOsnw8KY/l/1y+mQ8XNJ9MVdBGy1WB+uWB4teiyJchV49gn2XlKUK2rcCBvZ\n"
      "vC5CwPmFi2t70JezQgnXtDlbR0bARPlRd741i4rBpD7hEiZNCTOd2HFBpUg/CGWN\n"
      "E4n1ksazBm6jvv3Jo6WAa07Z390CgYEA1USrFqmc/fKGQpTCdH0qYZv3hQtrb1TQ\n"
      "9YnrbhtaC0haPpintZKjvhU3tCd1fPuIDXtMAgaaKSyoGiE2aMvLxt1/eV08BkMi\n"
      "kGIss9poYNi5+6ZD9QAHmHJhzZtVGj8U5L8379XmwxAByiBRVVE8CW1X/e6+iJpz\n"
      "+CLgN+zEVlsCgYEAsuOAdtxXJm4meERwL8b0cvNF3Eh1Sf/42MPTAwzCntSrh3w5\n"
      "InvwY/RtPHWnN/ScksEG7BWHhLafTCPDHJdp8hNcvIhNB68UBDln0loyYePP5pag\n"
      "sj4IUSbb7SUlR989elhrMTKQlM5K6QDAJrmjyVdM4S5urL9A3wgAyzAvyP0CgYAO\n"
      "paGuc8WxdzebWQYl4/bGL2UHgSpGwid7xZYiwMQlZDm2dNuHz+NpCaICwHcEN243\n"
      "ptEojnWGAGgnK0LGXcDIDqxTlICr2W6FRgjV7Vkf1aKoUtn1+KOM58YpzdJBdDWm\n"
      "JC/eS+2GVhIZZLDRUDv0VcsmSIBTd3AhiZumm588YwKBgBZfNqfmHAwIP2pM1wml\n"
      "Ck3vaLLvonghj3iQW9CFJ/SqLOnfT4KJkFObR6oGbxY0RtXsCrmSqidIKgDd0Kkq\n"
      "L6QbHp2j3+16GBdmLNUJlfjBTNPJp69IDKztjeCX7/8JZs79p/LAv+I9Sh4lVw4O\n"
      "IrDprlB0yzP5zigcsAZeViYJ\n"
      "-----END PRIVATE KEY-----\n"
      ;
    } else {
     key = File::getFile(key_path);
    }
    ctx.use_private_key(
        boost::asio::buffer(key.data(), key.size()),
        boost::asio::ssl::context::file_format::pem);

    ctx.use_tmp_dh(
        boost::asio::buffer(dh.data(), dh.size()));
}

int servername_callback(SSL *s, int *al, void *arg)
{
 int type {SSL_get_servername_type(s)};
 std::string server_name {SSL_get_servername(s, type)};

 HTTPS::Server::ctx_type* ctx_map = (HTTPS::Server::ctx_type*)arg;

 ssl::context& ctx = *(ctx_map->at(server_name));

 SSL_set_SSL_CTX(s, ctx.native_handle());
 
 return SSL_TLSEXT_ERR_OK;
}

} // anonymous namespace
//------------------------------------------------------------------------------

namespace HTTPS {

Server::Server(Config& config, boost::asio::io_context& ioc, const Socket& socket, plugins_container_type& plugins)
 : ::Server(config, ioc, socket, plugins)
{
 for (const auto& serve_site: socket.serve_sites) {
  for (const auto& site: config.Sites()) {
   if (site.name == serve_site) {
    std::shared_ptr<ssl::context> ctx {std::make_shared<ssl::context>(tls_method)};

    std::cout << "Creating SSL context/cert for site " << serve_site << " on port " << socket.port << std::endl;

    load_server_certificate(*ctx, site.cert_path, site.key_path);
    SSL_CTX_set_tlsext_servername_callback(ctx->native_handle(), servername_callback);
    SSL_CTX_set_tlsext_servername_arg(ctx->native_handle(), &m_ctx);

    for (const auto& host: site.hosts) {
     std::cout << "  Adding Host " << host << std::endl;
     m_ctx.emplace(host, ctx);
    }
   }
  }
 }
}

Server::~Server()
{
}

int Server::start()
{
 auto const address = net::ip::make_address(m_socket.address);
 auto const port = static_cast<unsigned short>(std::atoi(m_socket.port.data()));

 load_server_certificate(m_ctx_dummy, "", ""); // initial dummy, before we can add specific ctx w/ certificate
 SSL_CTX_set_tlsext_servername_callback(m_ctx_dummy.native_handle(), servername_callback);
 SSL_CTX_set_tlsext_servername_arg(m_ctx_dummy.native_handle(), &m_ctx);

 // Create and launch a listening port
 std::make_shared<listener>(
     m_ioc,
     m_ctx_dummy,
     tcp::endpoint{address, port},
     *this)->run();

 return EXIT_SUCCESS;
}

} // namespace HTTPS