Commit 23f32ba3 authored by louiz’'s avatar louiz’

Implement TLS support using Botan

For now, it tries two TLS ports and then connects to the non-tls port.  In
the future we would like the user to be able to configure that.

fix #2435
parent fa071309
......@@ -21,6 +21,7 @@ find_package(Iconv REQUIRED)
find_package(Libuuid REQUIRED)
find_package(Libidn)
find_package(SystemdDaemon)
find_package(Botan)
# To be able to include the config.h file generated by cmake
include_directories("${CMAKE_CURRENT_SOURCE_DIR}/src/")
......@@ -37,6 +38,10 @@ if(SYSTEMDDAEMON_FOUND)
include_directories(${SYSTEMDDAEMON_INCLUDE_DIRS})
endif()
if(BOTAN_FOUND)
include_directories(${BOTAN_INCLUDE_DIRS})
endif()
set(POLLER_DOCSTRING "Choose the poller between POLL and EPOLL (Linux-only)")
if(${CMAKE_SYSTEM_NAME} MATCHES "Linux")
set(POLLER "EPOLL" CACHE STRING ${POLLER_DOCSTRING})
......@@ -95,6 +100,9 @@ file(GLOB source_network
src/network/*.[hc]pp)
add_library(network STATIC ${source_network})
target_link_libraries(network logger)
if(BOTAN_FOUND)
target_link_libraries(network ${BOTAN_LIBRARIES})
endif()
#
## irclib
......
# - Find botan
# Find the botan cryptographic library
#
# This module defines the following variables:
# BOTAN_FOUND - True if library and include directory are found
# If set to TRUE, the following are also defined:
# BOTAN_INCLUDE_DIRS - The directory where to find the header file
# BOTAN_LIBRARIES - Where to find the library file
#
# For conveniance, these variables are also set. They have the same values
# than the variables above. The user can thus choose his/her prefered way
# to write them.
# BOTAN_LIBRARY
# BOTAN_INCLUDE_DIR
#
# This file is in the public domain
find_path(BOTAN_INCLUDE_DIRS NAMES botan/botan.h
DOC "The botan include directory")
find_library(BOTAN_LIBRARIES NAMES botan
DOC "The botan library")
# Use some standard module to handle the QUIETLY and REQUIRED arguments, and
# set BOTAN_FOUND to TRUE if these two variables are set.
include(FindPackageHandleStandardArgs)
find_package_handle_standard_args(Botan REQUIRED_VARS BOTAN_LIBRARIES BOTAN_INCLUDE_DIRS)
if(BOTAN_FOUND)
set(BOTAN_LIBRARY ${BOTAN_LIBRARIES})
set(BOTAN_INCLUDE_DIR ${BOTAN_INCLUDE_DIRS})
endif()
mark_as_advanced(BOTAN_INCLUDE_DIRS BOTAN_LIBRARIES)
......@@ -2,3 +2,4 @@
#cmakedefine LIBIDN_FOUND
#cmakedefine SYSTEMDDAEMON_FOUND
#cmakedefine POLLER ${POLLER}
#cmakedefine BOTAN_FOUND
\ No newline at end of file
......@@ -14,6 +14,8 @@
#include <chrono>
#include <string>
#include "config.h"
using namespace std::string_literals;
using namespace std::chrono_literals;
......@@ -35,6 +37,13 @@ IrcClient::IrcClient(std::shared_ptr<Poller> poller, const std::string& hostname
"alive without having to join a real channel of that server. "
"To disconnect from the IRC server, leave this room and all "
"other IRC channels of that server.";
// TODO: get the values from the preferences of the user, and only use the
// list of default ports if the user didn't specify anything
this->ports_to_try.emplace("6667", false); // standard non-encrypted port
#ifdef BOTAN_FOUND
this->ports_to_try.emplace("6670", true); // non-standard but I want it for some servers
this->ports_to_try.emplace("6697", true); // standard encrypted port
#endif // BOTAN_FOUND
}
IrcClient::~IrcClient()
......@@ -48,15 +57,22 @@ void IrcClient::start()
{
if (this->connected || this->connecting)
return ;
std::string port;
bool tls;
std::tie(port, tls) = this->ports_to_try.top();
this->ports_to_try.pop();
this->bridge->send_xmpp_message(this->hostname, "", "Connecting to "s +
this->hostname + ":" + "6667");
this->connect(this->hostname, "6667");
this->hostname + ":" + port + " (" +
(tls ? "encrypted" : "not encrypted") + ")");
this->connect(this->hostname, port, tls);
}
void IrcClient::on_connection_failed(const std::string& reason)
{
this->bridge->send_xmpp_message(this->hostname, "",
"Connection failed: "s + reason);
if (this->ports_to_try.empty())
{
// Send an error message for all room that the user wanted to join
for (const std::string& channel: this->channels_to_join)
{
......@@ -64,13 +80,16 @@ void IrcClient::on_connection_failed(const std::string& reason)
this->bridge->send_join_failed(iid, this->current_nick,
"cancel", "item-not-found", reason);
}
}
else // try the next port
this->start();
}
void IrcClient::on_connected()
{
this->send_nick_command(this->username);
this->send_user_command(this->username, this->username);
this->send_gateway_message("Connected to IRC server.");
this->send_gateway_message("Connected to IRC server"s + (this->use_tls ? " (encrypted)": "") + ".");
this->send_pending_data();
}
......@@ -326,7 +345,6 @@ void IrcClient::set_and_forward_user_list(const IrcMessage& message)
const IrcUser* user = channel->add_user(nick, this->prefix_to_mode);
if (user->nick != channel->get_self()->nick)
{
log_debug("Adding user [" << nick << "] to chan " << chan_name);
this->bridge->send_user_join(this->hostname, chan_name, user,
user->get_most_significant_mode(this->sorted_user_modes),
false);
......
......@@ -11,6 +11,7 @@
#include <memory>
#include <vector>
#include <string>
#include <stack>
#include <map>
#include <set>
......@@ -19,8 +20,6 @@ class Bridge;
/**
* Represent one IRC client, i.e. an endpoint connected to a single IRC
* server, through a TCP socket, receiving and sending commands to it.
*
* TODO: TLS support, maybe, but that's not high priority
*/
class IrcClient: public SocketHandler
{
......@@ -280,6 +279,12 @@ private:
* (for example 'ahov' is a common order).
*/
std::vector<char> sorted_user_modes;
/**
* A list of ports to which we will try to connect, in reverse. Each port
* is associated with a boolean telling if we should use TLS or not if the
* connection succeeds on that port.
*/
std::stack<std::pair<std::string, bool>> ports_to_try;
IrcClient(const IrcClient&) = delete;
IrcClient(IrcClient&&) = delete;
......
......@@ -10,26 +10,39 @@
#include <unistd.h>
#include <stdlib.h>
#include <errno.h>
#include <netdb.h>
#include <cstring>
#include <fcntl.h>
#include <netdb.h>
#include <stdio.h>
#include <iostream>
using namespace std::string_literals;
#ifdef BOTAN_FOUND
# include <botan/hex.h>
#endif
#ifndef UIO_FASTIOV
# define UIO_FASTIOV 8
#endif
using namespace std::string_literals;
namespace ph = std::placeholders;
SocketHandler::SocketHandler(std::shared_ptr<Poller> poller):
socket(-1),
poller(poller),
use_tls(false),
connected(false),
connecting(false)
{
}
#ifdef BOTAN_FOUND
,
rng(),
credential_manager(),
policy(),
session_manager(rng)
#endif
{}
void SocketHandler::init_socket(const struct addrinfo* rp)
{
......@@ -47,10 +60,11 @@ void SocketHandler::init_socket(const struct addrinfo* rp)
throw std::runtime_error("Could not initialize socket: "s + strerror(errno));
}
void SocketHandler::connect(const std::string& address, const std::string& port)
void SocketHandler::connect(const std::string& address, const std::string& port, const bool tls)
{
this->address = address;
this->port = port;
this->use_tls = tls;
utils::ScopeGuard sg;
......@@ -106,6 +120,10 @@ void SocketHandler::connect(const std::string& address, const std::string& port)
this->poller->add_socket_handler(this);
this->connected = true;
this->connecting = false;
#ifdef BOTAN_FOUND
if (this->use_tls)
this->start_tls();
#endif
this->on_connected();
return ;
}
......@@ -133,10 +151,20 @@ void SocketHandler::connect(const std::string& address, const std::string& port)
void SocketHandler::connect()
{
this->connect(this->address, this->port);
this->connect(this->address, this->port, this->use_tls);
}
void SocketHandler::on_recv()
{
#ifdef BOTAN_FOUND
if (this->use_tls)
this->tls_recv();
else
#endif
this->plain_recv();
}
void SocketHandler::plain_recv()
{
static constexpr size_t buf_size = 4096;
char buf[buf_size];
......@@ -145,6 +173,23 @@ void SocketHandler::on_recv()
if (recv_buf == nullptr)
recv_buf = buf;
const ssize_t size = this->do_recv(recv_buf, buf_size);
if (size > 0)
{
if (buf == recv_buf)
{
// data needs to be placed in the in_buf string, because no buffer
// was provided to receive that data directly. The in_buf buffer
// will be handled in parse_in_buffer()
this->in_buf += std::string(buf, size);
}
this->parse_in_buffer(size);
}
}
ssize_t SocketHandler::do_recv(void* recv_buf, const size_t buf_size)
{
ssize_t size = ::recv(this->socket, recv_buf, buf_size, 0);
if (0 == size)
{
......@@ -155,22 +200,17 @@ void SocketHandler::on_recv()
{
log_warning("Error while reading from socket: " << strerror(errno));
if (this->connecting)
this->on_connection_failed(strerror(errno));
else
this->on_connection_close();
{
this->close();
this->on_connection_failed(strerror(errno));
}
else
{
if (buf == recv_buf)
{
// data needs to be placed in the in_buf string, because no buffer
// was provided to receive that data directly. The in_buf buffer
// will be handled in parse_in_buffer()
this->in_buf += std::string(buf, size);
this->close();
this->on_connection_close();
}
this->parse_in_buffer(size);
}
return size;
}
void SocketHandler::on_send()
......@@ -241,6 +281,16 @@ socket_t SocketHandler::get_socket() const
}
void SocketHandler::send_data(std::string&& data)
{
#ifdef BOTAN_FOUND
if (this->use_tls)
this->tls_send(std::move(data));
else
#endif
this->raw_send(std::move(data));
}
void SocketHandler::raw_send(std::string&& data)
{
if (data.empty())
return ;
......@@ -269,3 +319,89 @@ void* SocketHandler::get_receive_buffer(const size_t) const
{
return nullptr;
}
#ifdef BOTAN_FOUND
void SocketHandler::start_tls()
{
Botan::TLS::Server_Information server_info(this->address, "irc", std::stoul(this->port));
this->tls = std::make_unique<Botan::TLS::Client>(
std::bind(&SocketHandler::tls_output_fn, this, ph::_1, ph::_2),
std::bind(&SocketHandler::tls_data_cb, this, ph::_1, ph::_2),
std::bind(&SocketHandler::tls_alert_cb, this, ph::_1, ph::_2, ph::_3),
std::bind(&SocketHandler::tls_handshake_cb, this, ph::_1),
session_manager, credential_manager, policy,
rng, server_info, Botan::TLS::Protocol_Version::latest_tls_version());
}
void SocketHandler::tls_recv()
{
static constexpr size_t buf_size = 4096;
char recv_buf[buf_size];
const ssize_t size = this->do_recv(recv_buf, buf_size);
if (size > 0)
{
const bool was_active = this->tls->is_active();
this->tls->received_data(reinterpret_cast<const Botan::byte*>(recv_buf),
static_cast<size_t>(size));
if (!was_active && this->tls->is_active())
this->on_tls_activated();
}
}
void SocketHandler::tls_send(std::string&& data)
{
if (this->tls->is_active())
{
const bool was_active = this->tls->is_active();
if (!this->pre_buf.empty())
{
this->tls->send(reinterpret_cast<const Botan::byte*>(this->pre_buf.data()),
this->pre_buf.size());
this->pre_buf = "";
}
if (!data.empty())
this->tls->send(reinterpret_cast<const Botan::byte*>(data.data()),
data.size());
if (!was_active && this->tls->is_active())
this->on_tls_activated();
}
else
this->pre_buf += data;
}
void SocketHandler::tls_data_cb(const Botan::byte* data, size_t size)
{
this->in_buf += std::string(reinterpret_cast<const char*>(data),
size);
if (!this->in_buf.empty())
this->parse_in_buffer(size);
}
void SocketHandler::tls_output_fn(const Botan::byte* data, size_t size)
{
this->raw_send(std::string(reinterpret_cast<const char*>(data), size));
}
void SocketHandler::tls_alert_cb(Botan::TLS::Alert alert, const Botan::byte*, size_t)
{
log_debug("tls_alert: " << alert.type_string());
}
bool SocketHandler::tls_handshake_cb(const Botan::TLS::Session& session)
{
log_debug("Handshake with " << session.server_info().hostname() << " complete."
<< " Version: " << session.version().to_string()
<< " using " << session.ciphersuite().to_string());
if (!session.session_id().empty())
log_debug("Session ID " << Botan::hex_encode(session.session_id()));
if (!session.session_ticket().empty())
log_debug("Session ticket " << Botan::hex_encode(session.session_ticket()));
return true;
}
void SocketHandler::on_tls_activated()
{
this->send_data("");
}
#endif // BOTAN_FOUND
#ifndef SOCKET_HANDLER_INCLUDED
# define SOCKET_HANDLER_INCLUDED
#include <logger/logger.hpp>
#include <sys/types.h>
#include <sys/socket.h>
#include <netdb.h>
......@@ -10,6 +12,26 @@
#include <string>
#include <list>
#include "config.h"
#ifdef BOTAN_FOUND
# include <botan/botan.h>
# include <botan/tls_client.h>
/**
* A very simple credential manager that accepts any certificate.
*/
class Permissive_Credentials_Manager: public Botan::Credentials_Manager
{
public:
void verify_certificate_chain(const std::string& type, const std::string& purported_hostname, const std::vector<Botan::X509_Certificate>&)
{ // TODO: Offer the admin to disallow connection on untrusted
// certificates
log_debug("Checking remote certificate (" << type << ") for hostname " << purported_hostname);
}
};
#endif // BOTAN_FOUND
typedef int socket_t;
class Poller;
......@@ -24,21 +46,19 @@ class SocketHandler
{
protected:
~SocketHandler() {}
public:
explicit SocketHandler(std::shared_ptr<Poller> poller);
/**
* Initialize the socket with the parameters contained in the given
* addrinfo structure.
*/
void init_socket(const struct addrinfo* rp);
/**
* Connect to the remote server, and call on_connected() if this succeeds
* Connect to the remote server, and call on_connected() if this
* succeeds. If tls is true, we set use_tls to true and will also call
* start_tls() when the connection succeeds.
*/
void connect(const std::string& address, const std::string& port);
void connect(const std::string& address, const std::string& port, const bool tls);
void connect();
/**
* Reads data in our in_buf and the call parse_in_buf, for the implementor
* to handle the data received so far.
* Reads raw data from the socket. And pass it to parse_in_buffer()
* If we are using TLS on this connection, we call tls_recv()
*/
void on_recv();
/**
......@@ -48,6 +68,9 @@ public:
/**
* Add the given data to out_buf and tell our poller that we want to be
* notified when a send event is ready.
*
* This can be overriden if we want to modify the data before sending
* it. For example if we want to encrypt it.
*/
void send_data(std::string&& data);
/**
......@@ -87,29 +110,94 @@ public:
bool is_connected() const;
bool is_connecting() const;
protected:
private:
/**
* Provide a buffer in which data can be directly received. This can be
* used to avoid copying data into in_buf before using it. If no buffer
* can provided, nullptr is returned (the default implementation does
* that).
* Initialize the socket with the parameters contained in the given
* addrinfo structure.
*/
virtual void* get_receive_buffer(const size_t size) const;
void init_socket(const struct addrinfo* rp);
/**
* The handled socket.
* Reads from the socket into the provided buffer. If an error occurs
* (read returns <= 0), the handling of the error is done here (close the
* connection, log a message, etc).
*
* Returns the value returned by ::recv(), so the buffer should not be
* used if it’s not positive.
*/
socket_t socket;
ssize_t do_recv(void* recv_buf, const size_t buf_size);
/**
* Where data read from the socket is added until we can extract a full
* and meaningful “message” from it.
*
* TODO: something more efficient than a string.
* Reads data from the socket and calls parse_in_buffer with it.
*/
std::string in_buf;
void plain_recv();
/**
* Mark the given data as ready to be sent, as-is, on the socket, as soon
* as we can.
*/
void raw_send(std::string&& data);
#ifdef BOTAN_FOUND
/**
* Create the TLS::Client object, with all the callbacks etc. This must be
* called only when we know we are able to send TLS-encrypted data over
* the socket.
*/
void start_tls();
/**
* An additional step to pass the data into our tls object to decrypt it
* before passing it to parse_in_buffer.
*/
void tls_recv();
/**
* Pass the data to the tls object in order to encrypt it. The tls object
* will then call raw_send as a callback whenever data as been encrypted
* and can be sent on the socket.
*/
void tls_send(std::string&& data);
/**
* Called by the tls object that some data has been decrypt. We call
* parse_in_buffer() to handle that unencrypted data.
*/
void tls_data_cb(const Botan::byte* data, size_t size);
/**
* Called by the tls object to indicate that some data has been encrypted
* and is now ready to be sent on the socket as is.
*/
void tls_output_fn(const Botan::byte* data, size_t size);
/**
* Called by the tls object to indicate that a TLS alert has been
* received. We don’t use it, we just log some message, at the moment.
*/
void tls_alert_cb(Botan::TLS::Alert alert, const Botan::byte*, size_t);
/**
* Called by the tls object at the end of the TLS handshake. We don't do
* anything here appart from logging the TLS session information.
*/
bool tls_handshake_cb(const Botan::TLS::Session& session);
/**
* Called whenever the tls session goes from inactive to active. This
* means that the handshake has just been successfully done, and we can
* now proceed to send any available data into our tls object.
*/
void on_tls_activated();
#endif // BOTAN_FOUND
/**
* The handled socket.
*/
socket_t socket;
/**
* Where data is added, when we want to send something to the client.
*/
std::list<std::string> out_buf;
/**
* Keep the details of the addrinfo the triggered a EINPROGRESS error when
* connect()ing to it, to reuse it directly when connect() is called
* again.
*/
struct addrinfo addrinfo;
struct sockaddr ai_addr;
socklen_t ai_addrlen;
protected:
/**
* A pointer to the poller that manages us, because we need to communicate
* with it, sometimes (for example to tell it that he now needs to watch
......@@ -119,6 +207,25 @@ protected:
* (actually it is sharing our ownership with a Bridge).
*/
std::shared_ptr<Poller> poller;
/**
* Where data read from the socket is added until we can extract a full
* and meaningful “message” from it.
*
* TODO: something more efficient than a string.
*/
std::string in_buf;
/**
* Whether we are using TLS on this connection or not.
*/
bool use_tls;
/**
* Provide a buffer in which data can be directly received. This can be
* used to avoid copying data into in_buf before using it. If no buffer
* needs to be provided, nullptr is returned (the default implementation
* does that), in that case our internal in_buf will be used to save the
* data until it can be used by parse_in_buffer().
*/
virtual void* get_receive_buffer(const size_t size) const;
/**
* Hostname we are connected/connecting to
*/
......@@ -127,14 +234,6 @@ protected:
* Port we are connected/connecting to
*/
std::string port;
/**
* Keep the details of the addrinfo the triggered a EINPROGRESS error when
* connect()ing to it, to reuse it directly when connect() is called
* again.
*/
struct addrinfo addrinfo;
struct sockaddr ai_addr;
socklen_t ai_addrlen;
bool connected;
bool connecting;
......@@ -144,6 +243,33 @@ private:
SocketHandler(SocketHandler&&) = delete;
SocketHandler& operator=(const SocketHandler&) = delete;
SocketHandler& operator=(SocketHandler&&) = delete;
#ifdef BOTAN_FOUND
/**
* Botan stuff to manipulate a TLS session.
*/
Botan::AutoSeeded_RNG rng;
Permissive_Credentials_Manager credential_manager;