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/*
* TLS Server Proxy
* (C) 2014,2015,2019 Jack Lloyd
* (C) 2016 Matthias Gierlings
*
* Botan is released under the Simplified BSD License (see license.txt)
*/
#include "cli.h"
#if defined(BOTAN_HAS_TLS) && defined(BOTAN_HAS_BOOST_ASIO) && defined(BOTAN_TARGET_OS_HAS_FILESYSTEM)
#include <iostream>
#include <string>
#include <vector>
#include <thread>
#include <atomic>
#define _GLIBCXX_HAVE_GTHR_DEFAULT
#include <boost/asio.hpp>
#include <boost/bind.hpp>
#include <botan/internal/os_utils.h>
#include <botan/tls_server.h>
#include <botan/x509cert.h>
#include <botan/pkcs8.h>
#include <botan/hex.h>
#include <botan/rng.h>
#if defined(BOTAN_HAS_TLS_SQLITE3_SESSION_MANAGER)
#include <botan/tls_session_manager_sqlite.h>
#endif
#include "tls_helpers.h"
#if BOOST_VERSION >= 107000
#define GET_IO_SERVICE(s) (static_cast<boost::asio::io_context&>((s).get_executor().context()))
#else
#define GET_IO_SERVICE(s) ((s).get_io_service())
#endif
namespace Botan_CLI {
namespace {
using boost::asio::ip::tcp;
void log_exception(const char* where, const std::exception& e)
{
std::cout << where << ' ' << e.what() << std::endl;
}
void log_error(const char* where, const boost::system::error_code& error)
{
std::cout << where << ' ' << error.message() << std::endl;
}
void log_binary_message(const char* where, const uint8_t buf[], size_t buf_len)
{
BOTAN_UNUSED(where, buf, buf_len);
//std::cout << where << ' ' << Botan::hex_encode(buf, buf_len) << std::endl;
}
void log_text_message(const char* where, const uint8_t buf[], size_t buf_len)
{
BOTAN_UNUSED(where, buf, buf_len);
//const char* c = reinterpret_cast<const char*>(buf);
//std::cout << where << ' ' << std::string(c, c + buf_len) << std::endl;
}
class ServerStatus
{
public:
ServerStatus(size_t max_clients) : m_max_clients(max_clients), m_clients_serviced(0) {}
bool should_exit() const
{
if(m_max_clients == 0)
return false;
return clients_serviced() >= m_max_clients;
}
void client_serviced() { m_clients_serviced++; }
size_t clients_serviced() const { return m_clients_serviced.load(); }
private:
size_t m_max_clients;
std::atomic<size_t> m_clients_serviced;
};
class tls_proxy_session final : public std::enable_shared_from_this<tls_proxy_session>,
public Botan::TLS::Callbacks
{
public:
enum { readbuf_size = 17 * 1024 };
typedef std::shared_ptr<tls_proxy_session> pointer;
static pointer create(
boost::asio::io_service& io,
Botan::TLS::Session_Manager& session_manager,
Botan::Credentials_Manager& credentials,
Botan::TLS::Policy& policy,
tcp::resolver::iterator endpoints)
{
return pointer(
new tls_proxy_session(
io,
session_manager,
credentials,
policy,
endpoints)
);
}
tcp::socket& client_socket()
{
return m_client_socket;
}
void start()
{
m_c2p.resize(readbuf_size);
client_read(boost::system::error_code(), 0); // start read loop
}
void stop()
{
if(m_is_closed == false)
{
/*
Don't need to talk to the server anymore
Client socket is closed during write callback
*/
m_server_socket.close();
m_tls.close();
m_is_closed = true;
}
}
private:
tls_proxy_session(
boost::asio::io_service& io,
Botan::TLS::Session_Manager& session_manager,
Botan::Credentials_Manager& credentials,
Botan::TLS::Policy& policy,
tcp::resolver::iterator endpoints)
: m_strand(io)
, m_server_endpoints(endpoints)
, m_client_socket(io)
, m_server_socket(io)
, m_rng(cli_make_rng())
, m_tls(*this,
session_manager,
credentials,
policy,
*m_rng) {}
void client_read(const boost::system::error_code& error,
size_t bytes_transferred)
{
if(error)
{
log_error("Read failed", error);
stop();
return;
}
try
{
if(!m_tls.is_active())
{
log_binary_message("From client", &m_c2p[0], bytes_transferred);
}
m_tls.received_data(&m_c2p[0], bytes_transferred);
}
catch(Botan::Exception& e)
{
log_exception("TLS connection failed", e);
stop();
return;
}
m_client_socket.async_read_some(
boost::asio::buffer(&m_c2p[0], m_c2p.size()),
m_strand.wrap(
boost::bind(
&tls_proxy_session::client_read, shared_from_this(),
boost::asio::placeholders::error,
boost::asio::placeholders::bytes_transferred)));
}
void handle_client_write_completion(const boost::system::error_code& error)
{
if(error)
{
log_error("Client write", error);
stop();
return;
}
m_p2c.clear();
if(m_p2c_pending.empty() && m_tls.is_closed())
{
m_client_socket.close();
}
tls_emit_data(nullptr, 0); // initiate another write if needed
}
void handle_server_write_completion(const boost::system::error_code& error)
{
if(error)
{
log_error("Server write", error);
stop();
return;
}
m_p2s.clear();
proxy_write_to_server(nullptr, 0); // initiate another write if needed
}
void tls_record_received(uint64_t /*rec_no*/, const uint8_t buf[], size_t buf_len) override
{
// Immediately bounce message to server
proxy_write_to_server(buf, buf_len);
}
void tls_emit_data(const uint8_t buf[], size_t buf_len) override
{
if(buf_len > 0)
{
m_p2c_pending.insert(m_p2c_pending.end(), buf, buf + buf_len);
}
// no write now active and we still have output pending
if(m_p2c.empty() && !m_p2c_pending.empty())
{
std::swap(m_p2c_pending, m_p2c);
log_binary_message("To Client", &m_p2c[0], m_p2c.size());
boost::asio::async_write(
m_client_socket,
boost::asio::buffer(&m_p2c[0], m_p2c.size()),
m_strand.wrap(
boost::bind(
&tls_proxy_session::handle_client_write_completion,
shared_from_this(),
boost::asio::placeholders::error)));
}
}
void proxy_write_to_server(const uint8_t buf[], size_t buf_len)
{
if(buf_len > 0)
{
m_p2s_pending.insert(m_p2s_pending.end(), buf, buf + buf_len);
}
// no write now active and we still have output pending
if(m_p2s.empty() && !m_p2s_pending.empty())
{
std::swap(m_p2s_pending, m_p2s);
log_text_message("To Server", &m_p2s[0], m_p2s.size());
boost::asio::async_write(
m_server_socket,
boost::asio::buffer(&m_p2s[0], m_p2s.size()),
m_strand.wrap(
boost::bind(
&tls_proxy_session::handle_server_write_completion,
shared_from_this(),
boost::asio::placeholders::error)));
}
}
void server_read(const boost::system::error_code& error,
size_t bytes_transferred)
{
if(error)
{
log_error("Server read failed", error);
stop();
return;
}
try
{
if(bytes_transferred)
{
log_text_message("Server to client", &m_s2p[0], m_s2p.size());
log_binary_message("Server to client", &m_s2p[0], m_s2p.size());
m_tls.send(&m_s2p[0], bytes_transferred);
}
}
catch(Botan::Exception& e)
{
log_exception("TLS connection failed", e);
stop();
return;
}
m_s2p.resize(readbuf_size);
m_server_socket.async_read_some(
boost::asio::buffer(&m_s2p[0], m_s2p.size()),
m_strand.wrap(
boost::bind(&tls_proxy_session::server_read, shared_from_this(),
boost::asio::placeholders::error,
boost::asio::placeholders::bytes_transferred)));
}
bool tls_session_established(const Botan::TLS::Session& session) override
{
m_hostname = session.server_info().hostname();
auto onConnect = [this](boost::system::error_code ec, tcp::resolver::iterator /*endpoint*/)
{
if(ec)
{
log_error("Server connection", ec);
return;
}
server_read(boost::system::error_code(), 0); // start read loop
proxy_write_to_server(nullptr, 0);
};
async_connect(m_server_socket, m_server_endpoints, onConnect);
return true;
}
void tls_alert(Botan::TLS::Alert alert) override
{
if(alert.type() == Botan::TLS::Alert::CLOSE_NOTIFY)
{
m_tls.close();
return;
}
}
boost::asio::io_service::strand m_strand;
tcp::resolver::iterator m_server_endpoints;
tcp::socket m_client_socket;
tcp::socket m_server_socket;
std::unique_ptr<Botan::RandomNumberGenerator> m_rng;
Botan::TLS::Server m_tls;
std::string m_hostname;
std::vector<uint8_t> m_c2p;
std::vector<uint8_t> m_p2c;
std::vector<uint8_t> m_p2c_pending;
std::vector<uint8_t> m_s2p;
std::vector<uint8_t> m_p2s;
std::vector<uint8_t> m_p2s_pending;
bool m_is_closed = false;
};
class tls_proxy_server final
{
public:
typedef tls_proxy_session session;
tls_proxy_server(
boost::asio::io_service& io, unsigned short port,
tcp::resolver::iterator endpoints,
Botan::Credentials_Manager& creds,
Botan::TLS::Policy& policy,
Botan::TLS::Session_Manager& session_mgr,
size_t max_clients)
: m_acceptor(io, tcp::endpoint(tcp::v4(), port))
, m_server_endpoints(endpoints)
, m_creds(creds)
, m_policy(policy)
, m_session_manager(session_mgr)
, m_status(max_clients)
{
session::pointer new_session = make_session();
m_acceptor.async_accept(
new_session->client_socket(),
boost::bind(
&tls_proxy_server::handle_accept,
this,
new_session,
boost::asio::placeholders::error));
}
private:
session::pointer make_session()
{
return session::create(
GET_IO_SERVICE(m_acceptor),
m_session_manager,
m_creds,
m_policy,
m_server_endpoints);
}
void handle_accept(session::pointer new_session,
const boost::system::error_code& error)
{
if(!error)
{
new_session->start();
new_session = make_session();
m_status.client_serviced();
if(m_status.should_exit() == false)
{
m_acceptor.async_accept(
new_session->client_socket(),
boost::bind(
&tls_proxy_server::handle_accept,
this,
new_session,
boost::asio::placeholders::error));
}
}
}
tcp::acceptor m_acceptor;
tcp::resolver::iterator m_server_endpoints;
Botan::Credentials_Manager& m_creds;
Botan::TLS::Policy& m_policy;
Botan::TLS::Session_Manager& m_session_manager;
ServerStatus m_status;
};
}
class TLS_Proxy final : public Command
{
public:
TLS_Proxy() : Command("tls_proxy listen_port target_host target_port server_cert server_key "
"--policy=default --threads=0 --max-clients=0 --session-db= --session-db-pass=") {}
std::string group() const override
{
return "tls";
}
std::string description() const override
{
return "Proxies requests between a TLS client and a TLS server";
}
size_t thread_count() const
{
if(size_t t = get_arg_sz("threads"))
return t;
if(size_t t = Botan::OS::get_cpu_available())
return t;
return 2;
}
void go() override
{
const uint16_t listen_port = get_arg_u16("listen_port");
const std::string target = get_arg("target_host");
const std::string target_port = get_arg("target_port");
const std::string server_crt = get_arg("server_cert");
const std::string server_key = get_arg("server_key");
const size_t num_threads = thread_count();
const size_t max_clients = get_arg_sz("max-clients");
Basic_Credentials_Manager creds(rng(), server_crt, server_key);
auto policy = load_tls_policy(get_arg("policy"));
boost::asio::io_service io;
tcp::resolver resolver(io);
auto server_endpoint_iterator = resolver.resolve({ target, target_port });
std::unique_ptr<Botan::TLS::Session_Manager> session_mgr;
#if defined(BOTAN_HAS_TLS_SQLITE3_SESSION_MANAGER)
const std::string sessions_passphrase = get_passphrase_arg("Session DB passphrase", "session-db-pass");
const std::string sessions_db = get_arg("session-db");
if(!sessions_db.empty())
{
session_mgr.reset(new Botan::TLS::Session_Manager_SQLite(sessions_passphrase, rng(), sessions_db));
}
#endif
if(!session_mgr)
{
session_mgr.reset(new Botan::TLS::Session_Manager_In_Memory(rng()));
}
tls_proxy_server server(io, listen_port, server_endpoint_iterator, creds, *policy, *session_mgr, max_clients);
std::vector<std::shared_ptr<std::thread>> threads;
// run forever... first thread is main calling io.run below
for(size_t i = 2; i <= num_threads; ++i)
{
threads.push_back(std::make_shared<std::thread>([&io]() { io.run(); }));
}
io.run();
for(size_t i = 0; i < threads.size(); ++i)
{
threads[i]->join();
}
}
};
BOTAN_REGISTER_COMMAND("tls_proxy", TLS_Proxy);
}
#endif