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tls.hpp
1 /*
2  * Copyright (c) 2015, Peter Thorson. All rights reserved.
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27 
28 #ifndef WEBSOCKETPP_TRANSPORT_SECURITY_TLS_HPP
29 #define WEBSOCKETPP_TRANSPORT_SECURITY_TLS_HPP
30 
31 #include <websocketpp/transport/asio/security/base.hpp>
32 
33 #include <websocketpp/uri.hpp>
34 
35 #include <websocketpp/common/asio_ssl.hpp>
36 #include <websocketpp/common/asio.hpp>
37 #include <websocketpp/common/connection_hdl.hpp>
38 #include <websocketpp/common/functional.hpp>
39 #include <websocketpp/common/memory.hpp>
40 
41 #include <sstream>
42 #include <string>
43 
44 namespace websocketpp {
45 namespace transport {
46 namespace asio {
47 /// A socket policy for the asio transport that implements a TLS encrypted
48 /// socket by wrapping with an asio::ssl::stream
49 namespace tls_socket {
50 
51 /// The signature of the socket_init_handler for this socket policy
52 typedef lib::function<void(connection_hdl,lib::asio::ssl::stream<
54 /// The signature of the tls_init_handler for this socket policy
57 
58 /// TLS enabled Asio connection socket component
59 /**
60  * transport::asio::tls_socket::connection implements a secure connection socket
61  * component that uses Asio's ssl::stream to wrap an ip::tcp::socket.
62  */
64 public:
65  /// Type of this connection socket component
66  typedef connection type;
67  /// Type of a shared pointer to this connection socket component
68  typedef lib::shared_ptr<type> ptr;
69 
70  /// Type of the ASIO socket being used
72  /// Type of a shared pointer to the ASIO socket being used
74  /// Type of a pointer to the ASIO io_service being used
76  /// Type of a pointer to the ASIO io_service strand being used
78  /// Type of a shared pointer to the ASIO TLS context being used
80 
81  explicit connection() {
82  //std::cout << "transport::asio::tls_socket::connection constructor"
83  // << std::endl;
84  }
85 
86  /// Get a shared pointer to this component
88  return shared_from_this();
89  }
90 
91  /// Check whether or not this connection is secure
92  /**
93  * @return Whether or not this connection is secure
94  */
95  bool is_secure() const {
96  return true;
97  }
98 
99  /// Retrieve a pointer to the underlying socket
100  /**
101  * This is used internally. It can also be used to set socket options, etc
102  */
104  return m_socket->lowest_layer();
105  }
106 
107  /// Retrieve a pointer to the layer below the ssl stream
108  /**
109  * This is used internally.
110  */
112  return m_socket->next_layer();
113  }
114 
115  /// Retrieve a pointer to the wrapped socket
116  /**
117  * This is used internally.
118  */
120  return *m_socket;
121  }
122 
123  /// Set the socket initialization handler
124  /**
125  * The socket initialization handler is called after the socket object is
126  * created but before it is used. This gives the application a chance to
127  * set any ASIO socket options it needs.
128  *
129  * @param h The new socket_init_handler
130  */
131  void set_socket_init_handler(socket_init_handler h) {
132  m_socket_init_handler = h;
133  }
134 
135  /// Set TLS init handler
136  /**
137  * The tls init handler is called when needed to request a TLS context for
138  * the library to use. A TLS init handler must be set and it must return a
139  * valid TLS context in order for this endpoint to be able to initialize
140  * TLS connections
141  *
142  * @param h The new tls_init_handler
143  */
144  void set_tls_init_handler(tls_init_handler h) {
145  m_tls_init_handler = h;
146  }
147 
148  /// Get the remote endpoint address
149  /**
150  * The iostream transport has no information about the ultimate remote
151  * endpoint. It will return the string "iostream transport". To indicate
152  * this.
153  *
154  * TODO: allow user settable remote endpoint addresses if this seems useful
155  *
156  * @return A string identifying the address of the remote endpoint
157  */
158  std::string get_remote_endpoint(lib::error_code & ec) const {
159  std::stringstream s;
160 
161  lib::asio::error_code aec;
162  lib::asio::ip::tcp::endpoint ep = m_socket->lowest_layer().remote_endpoint(aec);
163 
164  if (aec) {
165  ec = error::make_error_code(error::pass_through);
166  s << "Error getting remote endpoint: " << aec
167  << " (" << aec.message() << ")";
168  return s.str();
169  } else {
170  ec = lib::error_code();
171  s << ep;
172  return s.str();
173  }
174  }
175 protected:
176  /// Perform one time initializations
177  /**
178  * init_asio is called once immediately after construction to initialize
179  * Asio components to the io_service
180  *
181  * @param service A pointer to the endpoint's io_service
182  * @param strand A pointer to the connection's strand
183  * @param is_server Whether or not the endpoint is a server or not.
184  */
186  bool is_server)
187  {
188  if (!m_tls_init_handler) {
189  return socket::make_error_code(socket::error::missing_tls_init_handler);
190  }
191  m_context = m_tls_init_handler(m_hdl);
192 
193  if (!m_context) {
194  return socket::make_error_code(socket::error::invalid_tls_context);
195  }
196  m_socket = lib::make_shared<socket_type>(
197  _WEBSOCKETPP_REF(*service),lib::ref(*m_context));
198 
199  if (m_socket_init_handler) {
200  m_socket_init_handler(m_hdl, get_socket());
201  }
202 
203  m_io_service = service;
204  m_strand = strand;
205  m_is_server = is_server;
206 
207  return lib::error_code();
208  }
209 
210  /// Set hostname hook
211  /**
212  * Called by the transport as a connection is being established to provide
213  * the hostname being connected to to the security/socket layer.
214  *
215  * This socket policy uses the hostname to set the appropriate TLS SNI
216  * header.
217  *
218  * @since 0.6.0
219  *
220  * @param u The uri to set
221  */
222  void set_uri(uri_ptr u) {
223  m_uri = u;
224  }
225 
226  /// Pre-initialize security policy
227  /**
228  * Called by the transport after a new connection is created to initialize
229  * the socket component of the connection. This method is not allowed to
230  * write any bytes to the wire. This initialization happens before any
231  * proxies or other intermediate wrappers are negotiated.
232  *
233  * @param callback Handler to call back with completion information
234  */
235  void pre_init(init_handler callback) {
236  // TODO: is this the best way to check whether this function is
237  // available in the version of OpenSSL being used?
238  // TODO: consider case where host is an IP address
239 #if OPENSSL_VERSION_NUMBER >= 0x90812f
240  if (!m_is_server) {
241  // For clients on systems with a suitable OpenSSL version, set the
242  // TLS SNI hostname header so connecting to TLS servers using SNI
243  // will work.
244  long res = SSL_set_tlsext_host_name(
245  get_socket().native_handle(), m_uri->get_host().c_str());
246  if (!(1 == res)) {
247  callback(socket::make_error_code(socket::error::tls_failed_sni_hostname));
248  }
249  }
250 #endif
251 
252  callback(lib::error_code());
253  }
254 
255  /// Post-initialize security policy
256  /**
257  * Called by the transport after all intermediate proxies have been
258  * negotiated. This gives the security policy the chance to talk with the
259  * real remote endpoint for a bit before the websocket handshake.
260  *
261  * @param callback Handler to call back with completion information
262  */
263  void post_init(init_handler callback) {
264  m_ec = socket::make_error_code(socket::error::tls_handshake_timeout);
265 
266  // TLS handshake
267  if (m_strand) {
268  m_socket->async_handshake(
269  get_handshake_type(),
270  m_strand->wrap(lib::bind(
271  &type::handle_init, get_shared(),
272  callback,
273  lib::placeholders::_1
274  ))
275  );
276  } else {
277  m_socket->async_handshake(
278  get_handshake_type(),
279  lib::bind(
280  &type::handle_init, get_shared(),
281  callback,
282  lib::placeholders::_1
283  )
284  );
285  }
286  }
287 
288  /// Sets the connection handle
289  /**
290  * The connection handle is passed to any handlers to identify the
291  * connection
292  *
293  * @param hdl The new handle
294  */
295  void set_handle(connection_hdl hdl) {
296  m_hdl = hdl;
297  }
298 
299  void handle_init(init_handler callback,lib::asio::error_code const & ec) {
300  if (ec) {
301  m_ec = socket::make_error_code(socket::error::tls_handshake_failed);
302  } else {
303  m_ec = lib::error_code();
304  }
305 
306  callback(m_ec);
307  }
308 
309  lib::error_code get_ec() const {
310  return m_ec;
311  }
312 
313  /// Cancel all async operations on this socket
314  /**
315  * Attempts to cancel all async operations on this socket and reports any
316  * failures.
317  *
318  * NOTE: Windows XP and earlier do not support socket cancellation.
319  *
320  * @return The error that occurred, if any.
321  */
323  lib::asio::error_code ec;
324  get_raw_socket().cancel(ec);
325  return ec;
326  }
327 
328  void async_shutdown(socket::shutdown_handler callback) {
329  if (m_strand) {
330  m_socket->async_shutdown(m_strand->wrap(callback));
331  } else {
332  m_socket->async_shutdown(callback);
333  }
334  }
335 
336  /// Translate any security policy specific information about an error code
337  /**
338  * Translate_ec takes an Asio error code and attempts to convert its value
339  * to an appropriate websocketpp error code. In the case that the Asio and
340  * Websocketpp error types are the same (such as using boost::asio and
341  * boost::system_error or using standalone asio and std::system_error the
342  * code will be passed through natively.
343  *
344  * In the case of a mismatch (boost::asio with std::system_error) a
345  * translated code will be returned. Any error that is determined to be
346  * related to TLS but does not have a more specific websocketpp error code
347  * is returned under the catch all error `tls_error`. Non-TLS related errors
348  * are returned as the transport generic error `pass_through`
349  *
350  * @since 0.3.0
351  *
352  * @param ec The error code to translate_ec
353  * @return The translated error code
354  */
355  template <typename ErrorCodeType>
357  if (ec.category() == lib::asio::error::get_ssl_category()) {
358  if (ERR_GET_REASON(ec.value()) == SSL_R_SHORT_READ) {
359  return make_error_code(transport::error::tls_short_read);
360  } else {
361  // We know it is a TLS related error, but otherwise don't know
362  // more. Pass through as TLS generic.
363  return make_error_code(transport::error::tls_error);
364  }
365  } else {
366  // We don't know any more information about this error so pass
367  // through
368  return make_error_code(transport::error::pass_through);
369  }
370  }
371 
372  /// Overload of translate_ec to catch cases where lib::error_code is the
373  /// same type as lib::asio::error_code
375  // Normalize the tls_short_read error as it is used by the library and
376  // needs a consistent value. All other errors pass through natively.
377  // TODO: how to get the SSL category from std::error?
378  /*if (ec.category() == lib::asio::error::get_ssl_category()) {
379  if (ERR_GET_REASON(ec.value()) == SSL_R_SHORT_READ) {
380  return make_error_code(transport::error::tls_short_read);
381  }
382  }*/
383  return ec;
384  }
385 private:
386  socket_type::handshake_type get_handshake_type() {
387  if (m_is_server) {
388  return lib::asio::ssl::stream_base::server;
389  } else {
390  return lib::asio::ssl::stream_base::client;
391  }
392  }
393 
394  io_service_ptr m_io_service;
395  strand_ptr m_strand;
396  context_ptr m_context;
397  socket_ptr m_socket;
398  uri_ptr m_uri;
399  bool m_is_server;
400 
401  lib::error_code m_ec;
402 
403  connection_hdl m_hdl;
404  socket_init_handler m_socket_init_handler;
405  tls_init_handler m_tls_init_handler;
406 };
407 
408 /// TLS enabled Asio endpoint socket component
409 /**
410  * transport::asio::tls_socket::endpoint implements a secure endpoint socket
411  * component that uses Asio's ssl::stream to wrap an ip::tcp::socket.
412  */
413 class endpoint {
414 public:
415  /// The type of this endpoint socket component
416  typedef endpoint type;
417 
418  /// The type of the corresponding connection socket component
420  /// The type of a shared pointer to the corresponding connection socket
421  /// component.
423 
424  explicit endpoint() {}
425 
426  /// Checks whether the endpoint creates secure connections
427  /**
428  * @return Whether or not the endpoint creates secure connections
429  */
430  bool is_secure() const {
431  return true;
432  }
433 
434  /// Set socket init handler
435  /**
436  * The socket init handler is called after a connection's socket is created
437  * but before it is used. This gives the end application an opportunity to
438  * set asio socket specific parameters.
439  *
440  * @param h The new socket_init_handler
441  */
442  void set_socket_init_handler(socket_init_handler h) {
443  m_socket_init_handler = h;
444  }
445 
446  /// Set TLS init handler
447  /**
448  * The tls init handler is called when needed to request a TLS context for
449  * the library to use. A TLS init handler must be set and it must return a
450  * valid TLS context in order for this endpoint to be able to initialize
451  * TLS connections
452  *
453  * @param h The new tls_init_handler
454  */
455  void set_tls_init_handler(tls_init_handler h) {
456  m_tls_init_handler = h;
457  }
458 protected:
459  /// Initialize a connection
460  /**
461  * Called by the transport after a new connection is created to initialize
462  * the socket component of the connection.
463  *
464  * @param scon Pointer to the socket component of the connection
465  *
466  * @return Error code (empty on success)
467  */
469  scon->set_socket_init_handler(m_socket_init_handler);
470  scon->set_tls_init_handler(m_tls_init_handler);
471  return lib::error_code();
472  }
473 
474 private:
475  socket_init_handler m_socket_init_handler;
476  tls_init_handler m_tls_init_handler;
477 };
478 
479 } // namespace tls_socket
480 } // namespace asio
481 } // namespace transport
482 } // namespace websocketpp
483 
484 #endif // WEBSOCKETPP_TRANSPORT_SECURITY_TLS_HPP
socket_type & get_socket()
Retrieve a pointer to the wrapped socket.
Definition: tls.hpp:119
lib::asio::error_code cancel_socket()
Cancel all async operations on this socket.
Definition: tls.hpp:322
bool is_secure() const
Checks whether the endpoint creates secure connections.
Definition: tls.hpp:430
void pre_init(init_handler callback)
Pre-initialize security policy.
Definition: tls.hpp:235
bool is_secure() const
Check whether or not this connection is secure.
Definition: tls.hpp:95
connection type
Type of this connection socket component.
Definition: tls.hpp:66
void set_handle(connection_hdl hdl)
Sets the connection handle.
Definition: tls.hpp:295
lib::function< lib::shared_ptr< lib::asio::ssl::context >connection_hdl)> tls_init_handler
The signature of the tls_init_handler for this socket policy.
Definition: tls.hpp:56
lib::error_code translate_ec(ErrorCodeType ec)
Translate any security policy specific information about an error code.
Definition: tls.hpp:356
lib::error_code init(socket_con_ptr scon)
Initialize a connection.
Definition: tls.hpp:468
socket_type::next_layer_type & get_next_layer()
Retrieve a pointer to the layer below the ssl stream.
Definition: tls.hpp:111
connection socket_con_type
The type of the corresponding connection socket component.
Definition: tls.hpp:419
std::string get_remote_endpoint(lib::error_code &ec) const
Get the remote endpoint address.
Definition: tls.hpp:158
void set_tls_init_handler(tls_init_handler h)
Set TLS init handler.
Definition: tls.hpp:455
lib::shared_ptr< lib::asio::ssl::context > context_ptr
Type of a shared pointer to the ASIO TLS context being used.
Definition: tls.hpp:79
void set_uri(uri_ptr u)
Set hostname hook.
Definition: tls.hpp:222
void set_socket_init_handler(socket_init_handler h)
Set socket init handler.
Definition: tls.hpp:442
lib::asio::io_service * io_service_ptr
Type of a pointer to the ASIO io_service being used.
Definition: tls.hpp:75
ptr get_shared()
Get a shared pointer to this component.
Definition: tls.hpp:87
lib::error_code init_asio(io_service_ptr service, strand_ptr strand, bool is_server)
Perform one time initializations.
Definition: tls.hpp:185
socket_type::lowest_layer_type & get_raw_socket()
Retrieve a pointer to the underlying socket.
Definition: tls.hpp:103
endpoint type
The type of this endpoint socket component.
Definition: tls.hpp:416
void handle_accept(connection_ptr con, lib::error_code const &ec)
Handler callback for start_accept.
void set_tls_init_handler(tls_init_handler h)
Set TLS init handler.
Definition: tls.hpp:144
void set_socket_init_handler(socket_init_handler h)
Set the socket initialization handler.
Definition: tls.hpp:131
void post_init(init_handler callback)
Post-initialize security policy.
Definition: tls.hpp:263
TLS enabled Asio endpoint socket component.
Definition: tls.hpp:413
lib::error_code translate_ec(lib::error_code ec)
Definition: tls.hpp:374
lib::function< void(lib::error_code const &)> connect_handler
The type and signature of the callback passed to the connect method.
Definition: endpoint.hpp:72