1 /*
2  * This file is part of gtkD.
3  *
4  * gtkD is free software; you can redistribute it and/or modify
5  * it under the terms of the GNU Lesser General Public License
6  * as published by the Free Software Foundation; either version 3
7  * of the License, or (at your option) any later version, with
8  * some exceptions, please read the COPYING file.
9  *
10  * gtkD is distributed in the hope that it will be useful,
11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
13  * GNU Lesser General Public License for more details.
14  *
15  * You should have received a copy of the GNU Lesser General Public License
16  * along with gtkD; if not, write to the Free Software
17  * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110, USA
18  */
19 
20 // generated automatically - do not change
21 // find conversion definition on APILookup.txt
22 // implement new conversion functionalities on the wrap.utils pakage
23 
24 
25 module gio.TlsConnection;
26 
27 private import gio.AsyncResultIF;
28 private import gio.Cancellable;
29 private import gio.IOStream;
30 private import gio.TlsCertificate;
31 private import gio.TlsDatabase;
32 private import gio.TlsInteraction;
33 private import gio.c.functions;
34 public  import gio.c.types;
35 private import glib.ByteArray;
36 private import glib.ErrorG;
37 private import glib.GException;
38 private import glib.MemorySlice;
39 private import glib.Str;
40 private import glib.c.functions;
41 private import gobject.ObjectG;
42 private import gobject.Signals;
43 private import std.algorithm;
44 
45 
46 /**
47  * #GTlsConnection is the base TLS connection class type, which wraps
48  * a #GIOStream and provides TLS encryption on top of it. Its
49  * subclasses, #GTlsClientConnection and #GTlsServerConnection,
50  * implement client-side and server-side TLS, respectively.
51  * 
52  * For DTLS (Datagram TLS) support, see #GDtlsConnection.
53  *
54  * Since: 2.28
55  */
56 public class TlsConnection : IOStream
57 {
58 	/** the main Gtk struct */
59 	protected GTlsConnection* gTlsConnection;
60 
61 	/** Get the main Gtk struct */
62 	public GTlsConnection* getTlsConnectionStruct(bool transferOwnership = false)
63 	{
64 		if (transferOwnership)
65 			ownedRef = false;
66 		return gTlsConnection;
67 	}
68 
69 	/** the main Gtk struct as a void* */
70 	protected override void* getStruct()
71 	{
72 		return cast(void*)gTlsConnection;
73 	}
74 
75 	/**
76 	 * Sets our main struct and passes it to the parent class.
77 	 */
78 	public this (GTlsConnection* gTlsConnection, bool ownedRef = false)
79 	{
80 		this.gTlsConnection = gTlsConnection;
81 		super(cast(GIOStream*)gTlsConnection, ownedRef);
82 	}
83 
84 
85 	/** */
86 	public static GType getType()
87 	{
88 		return g_tls_connection_get_type();
89 	}
90 
91 	/**
92 	 * Used by #GTlsConnection implementations to emit the
93 	 * #GTlsConnection::accept-certificate signal.
94 	 *
95 	 * Params:
96 	 *     peerCert = the peer's #GTlsCertificate
97 	 *     errors = the problems with @peer_cert
98 	 *
99 	 * Returns: %TRUE if one of the signal handlers has returned
100 	 *     %TRUE to accept @peer_cert
101 	 *
102 	 * Since: 2.28
103 	 */
104 	public bool emitAcceptCertificate(TlsCertificate peerCert, GTlsCertificateFlags errors)
105 	{
106 		return g_tls_connection_emit_accept_certificate(gTlsConnection, (peerCert is null) ? null : peerCert.getTlsCertificateStruct(), errors) != 0;
107 	}
108 
109 	/**
110 	 * Gets @conn's certificate, as set by
111 	 * g_tls_connection_set_certificate().
112 	 *
113 	 * Returns: @conn's certificate, or %NULL
114 	 *
115 	 * Since: 2.28
116 	 */
117 	public TlsCertificate getCertificate()
118 	{
119 		auto __p = g_tls_connection_get_certificate(gTlsConnection);
120 
121 		if(__p is null)
122 		{
123 			return null;
124 		}
125 
126 		return ObjectG.getDObject!(TlsCertificate)(cast(GTlsCertificate*) __p);
127 	}
128 
129 	/**
130 	 * Query the TLS backend for TLS channel binding data of @type for @conn.
131 	 *
132 	 * This call retrieves TLS channel binding data as specified in RFC
133 	 * [5056](https://tools.ietf.org/html/rfc5056), RFC
134 	 * [5929](https://tools.ietf.org/html/rfc5929), and related RFCs.  The
135 	 * binding data is returned in @data.  The @data is resized by the callee
136 	 * using #GByteArray buffer management and will be freed when the @data
137 	 * is destroyed by g_byte_array_unref(). If @data is %NULL, it will only
138 	 * check whether TLS backend is able to fetch the data (e.g. whether @type
139 	 * is supported by the TLS backend). It does not guarantee that the data
140 	 * will be available though.  That could happen if TLS connection does not
141 	 * support @type or the binding data is not available yet due to additional
142 	 * negotiation or input required.
143 	 *
144 	 * Params:
145 	 *     type = #GTlsChannelBindingType type of data to fetch
146 	 *     data = #GByteArray is
147 	 *         filled with the binding data, or %NULL
148 	 *
149 	 * Returns: %TRUE on success, %FALSE otherwise
150 	 *
151 	 * Since: 2.66
152 	 *
153 	 * Throws: GException on failure.
154 	 */
155 	public bool getChannelBindingData(GTlsChannelBindingType type, out ByteArray data)
156 	{
157 		GByteArray* outdata = sliceNew!GByteArray();
158 		GError* err = null;
159 
160 		auto __p = g_tls_connection_get_channel_binding_data(gTlsConnection, type, outdata, &err) != 0;
161 
162 		if (err !is null)
163 		{
164 			throw new GException( new ErrorG(err) );
165 		}
166 
167 		data = new ByteArray(outdata, true);
168 
169 		return __p;
170 	}
171 
172 	/**
173 	 * Returns the name of the current TLS ciphersuite, or %NULL if the
174 	 * connection has not handshaked or has been closed. Beware that the TLS
175 	 * backend may use any of multiple different naming conventions, because
176 	 * OpenSSL and GnuTLS have their own ciphersuite naming conventions that
177 	 * are different from each other and different from the standard, IANA-
178 	 * registered ciphersuite names. The ciphersuite name is intended to be
179 	 * displayed to the user for informative purposes only, and parsing it
180 	 * is not recommended.
181 	 *
182 	 * Returns: The name of the current TLS ciphersuite, or %NULL
183 	 *
184 	 * Since: 2.70
185 	 */
186 	public string getCiphersuiteName()
187 	{
188 		auto retStr = g_tls_connection_get_ciphersuite_name(gTlsConnection);
189 
190 		scope(exit) Str.freeString(retStr);
191 		return Str.toString(retStr);
192 	}
193 
194 	/**
195 	 * Gets the certificate database that @conn uses to verify
196 	 * peer certificates. See g_tls_connection_set_database().
197 	 *
198 	 * Returns: the certificate database that @conn uses or %NULL
199 	 *
200 	 * Since: 2.30
201 	 */
202 	public TlsDatabase getDatabase()
203 	{
204 		auto __p = g_tls_connection_get_database(gTlsConnection);
205 
206 		if(__p is null)
207 		{
208 			return null;
209 		}
210 
211 		return ObjectG.getDObject!(TlsDatabase)(cast(GTlsDatabase*) __p);
212 	}
213 
214 	/**
215 	 * Get the object that will be used to interact with the user. It will be used
216 	 * for things like prompting the user for passwords. If %NULL is returned, then
217 	 * no user interaction will occur for this connection.
218 	 *
219 	 * Returns: The interaction object.
220 	 *
221 	 * Since: 2.30
222 	 */
223 	public TlsInteraction getInteraction()
224 	{
225 		auto __p = g_tls_connection_get_interaction(gTlsConnection);
226 
227 		if(__p is null)
228 		{
229 			return null;
230 		}
231 
232 		return ObjectG.getDObject!(TlsInteraction)(cast(GTlsInteraction*) __p);
233 	}
234 
235 	/**
236 	 * Gets the name of the application-layer protocol negotiated during
237 	 * the handshake.
238 	 *
239 	 * If the peer did not use the ALPN extension, or did not advertise a
240 	 * protocol that matched one of @conn's protocols, or the TLS backend
241 	 * does not support ALPN, then this will be %NULL. See
242 	 * g_tls_connection_set_advertised_protocols().
243 	 *
244 	 * Returns: the negotiated protocol, or %NULL
245 	 *
246 	 * Since: 2.60
247 	 */
248 	public string getNegotiatedProtocol()
249 	{
250 		return Str.toString(g_tls_connection_get_negotiated_protocol(gTlsConnection));
251 	}
252 
253 	/**
254 	 * Gets @conn's peer's certificate after the handshake has completed
255 	 * or failed. (It is not set during the emission of
256 	 * #GTlsConnection::accept-certificate.)
257 	 *
258 	 * Returns: @conn's peer's certificate, or %NULL
259 	 *
260 	 * Since: 2.28
261 	 */
262 	public TlsCertificate getPeerCertificate()
263 	{
264 		auto __p = g_tls_connection_get_peer_certificate(gTlsConnection);
265 
266 		if(__p is null)
267 		{
268 			return null;
269 		}
270 
271 		return ObjectG.getDObject!(TlsCertificate)(cast(GTlsCertificate*) __p);
272 	}
273 
274 	/**
275 	 * Gets the errors associated with validating @conn's peer's
276 	 * certificate, after the handshake has completed or failed. (It is
277 	 * not set during the emission of #GTlsConnection::accept-certificate.)
278 	 *
279 	 * See #GTlsConnection:peer-certificate-errors for more information.
280 	 *
281 	 * Returns: @conn's peer's certificate errors
282 	 *
283 	 * Since: 2.28
284 	 */
285 	public GTlsCertificateFlags getPeerCertificateErrors()
286 	{
287 		return g_tls_connection_get_peer_certificate_errors(gTlsConnection);
288 	}
289 
290 	/**
291 	 * Returns the current TLS protocol version, which may be
292 	 * %G_TLS_PROTOCOL_VERSION_UNKNOWN if the connection has not handshaked, or
293 	 * has been closed, or if the TLS backend has implemented a protocol version
294 	 * that is not a recognized #GTlsProtocolVersion.
295 	 *
296 	 * Returns: The current TLS protocol version
297 	 *
298 	 * Since: 2.70
299 	 */
300 	public GTlsProtocolVersion getProtocolVersion()
301 	{
302 		return g_tls_connection_get_protocol_version(gTlsConnection);
303 	}
304 
305 	/**
306 	 * Gets @conn rehandshaking mode. See
307 	 * g_tls_connection_set_rehandshake_mode() for details.
308 	 *
309 	 * Deprecated: Changing the rehandshake mode is no longer
310 	 * required for compatibility. Also, rehandshaking has been removed
311 	 * from the TLS protocol in TLS 1.3.
312 	 *
313 	 * Returns: %G_TLS_REHANDSHAKE_SAFELY
314 	 *
315 	 * Since: 2.28
316 	 */
317 	public GTlsRehandshakeMode getRehandshakeMode()
318 	{
319 		return g_tls_connection_get_rehandshake_mode(gTlsConnection);
320 	}
321 
322 	/**
323 	 * Tests whether or not @conn expects a proper TLS close notification
324 	 * when the connection is closed. See
325 	 * g_tls_connection_set_require_close_notify() for details.
326 	 *
327 	 * Returns: %TRUE if @conn requires a proper TLS close
328 	 *     notification.
329 	 *
330 	 * Since: 2.28
331 	 */
332 	public bool getRequireCloseNotify()
333 	{
334 		return g_tls_connection_get_require_close_notify(gTlsConnection) != 0;
335 	}
336 
337 	/**
338 	 * Gets whether @conn uses the system certificate database to verify
339 	 * peer certificates. See g_tls_connection_set_use_system_certdb().
340 	 *
341 	 * Deprecated: Use g_tls_connection_get_database() instead
342 	 *
343 	 * Returns: whether @conn uses the system certificate database
344 	 */
345 	public bool getUseSystemCertdb()
346 	{
347 		return g_tls_connection_get_use_system_certdb(gTlsConnection) != 0;
348 	}
349 
350 	/**
351 	 * Attempts a TLS handshake on @conn.
352 	 *
353 	 * On the client side, it is never necessary to call this method;
354 	 * although the connection needs to perform a handshake after
355 	 * connecting (or after sending a "STARTTLS"-type command),
356 	 * #GTlsConnection will handle this for you automatically when you try
357 	 * to send or receive data on the connection. You can call
358 	 * g_tls_connection_handshake() manually if you want to know whether
359 	 * the initial handshake succeeded or failed (as opposed to just
360 	 * immediately trying to use @conn to read or write, in which case,
361 	 * if it fails, it may not be possible to tell if it failed before or
362 	 * after completing the handshake), but beware that servers may reject
363 	 * client authentication after the handshake has completed, so a
364 	 * successful handshake does not indicate the connection will be usable.
365 	 *
366 	 * Likewise, on the server side, although a handshake is necessary at
367 	 * the beginning of the communication, you do not need to call this
368 	 * function explicitly unless you want clearer error reporting.
369 	 *
370 	 * Previously, calling g_tls_connection_handshake() after the initial
371 	 * handshake would trigger a rehandshake; however, this usage was
372 	 * deprecated in GLib 2.60 because rehandshaking was removed from the
373 	 * TLS protocol in TLS 1.3. Since GLib 2.64, calling this function after
374 	 * the initial handshake will no longer do anything.
375 	 *
376 	 * When using a #GTlsConnection created by #GSocketClient, the
377 	 * #GSocketClient performs the initial handshake, so calling this
378 	 * function manually is not recommended.
379 	 *
380 	 * #GTlsConnection::accept_certificate may be emitted during the
381 	 * handshake.
382 	 *
383 	 * Params:
384 	 *     cancellable = a #GCancellable, or %NULL
385 	 *
386 	 * Returns: success or failure
387 	 *
388 	 * Since: 2.28
389 	 *
390 	 * Throws: GException on failure.
391 	 */
392 	public bool handshake(Cancellable cancellable)
393 	{
394 		GError* err = null;
395 
396 		auto __p = g_tls_connection_handshake(gTlsConnection, (cancellable is null) ? null : cancellable.getCancellableStruct(), &err) != 0;
397 
398 		if (err !is null)
399 		{
400 			throw new GException( new ErrorG(err) );
401 		}
402 
403 		return __p;
404 	}
405 
406 	/**
407 	 * Asynchronously performs a TLS handshake on @conn. See
408 	 * g_tls_connection_handshake() for more information.
409 	 *
410 	 * Params:
411 	 *     ioPriority = the [I/O priority][io-priority] of the request
412 	 *     cancellable = a #GCancellable, or %NULL
413 	 *     callback = callback to call when the handshake is complete
414 	 *     userData = the data to pass to the callback function
415 	 *
416 	 * Since: 2.28
417 	 */
418 	public void handshakeAsync(int ioPriority, Cancellable cancellable, GAsyncReadyCallback callback, void* userData)
419 	{
420 		g_tls_connection_handshake_async(gTlsConnection, ioPriority, (cancellable is null) ? null : cancellable.getCancellableStruct(), callback, userData);
421 	}
422 
423 	/**
424 	 * Finish an asynchronous TLS handshake operation. See
425 	 * g_tls_connection_handshake() for more information.
426 	 *
427 	 * Params:
428 	 *     result = a #GAsyncResult.
429 	 *
430 	 * Returns: %TRUE on success, %FALSE on failure, in which
431 	 *     case @error will be set.
432 	 *
433 	 * Since: 2.28
434 	 *
435 	 * Throws: GException on failure.
436 	 */
437 	public bool handshakeFinish(AsyncResultIF result)
438 	{
439 		GError* err = null;
440 
441 		auto __p = g_tls_connection_handshake_finish(gTlsConnection, (result is null) ? null : result.getAsyncResultStruct(), &err) != 0;
442 
443 		if (err !is null)
444 		{
445 			throw new GException( new ErrorG(err) );
446 		}
447 
448 		return __p;
449 	}
450 
451 	/**
452 	 * Sets the list of application-layer protocols to advertise that the
453 	 * caller is willing to speak on this connection. The
454 	 * Application-Layer Protocol Negotiation (ALPN) extension will be
455 	 * used to negotiate a compatible protocol with the peer; use
456 	 * g_tls_connection_get_negotiated_protocol() to find the negotiated
457 	 * protocol after the handshake.  Specifying %NULL for the the value
458 	 * of @protocols will disable ALPN negotiation.
459 	 *
460 	 * See [IANA TLS ALPN Protocol IDs](https://www.iana.org/assignments/tls-extensiontype-values/tls-extensiontype-values.xhtml#alpn-protocol-ids)
461 	 * for a list of registered protocol IDs.
462 	 *
463 	 * Params:
464 	 *     protocols = a %NULL-terminated
465 	 *         array of ALPN protocol names (eg, "http/1.1", "h2"), or %NULL
466 	 *
467 	 * Since: 2.60
468 	 */
469 	public void setAdvertisedProtocols(string[] protocols)
470 	{
471 		g_tls_connection_set_advertised_protocols(gTlsConnection, Str.toStringzArray(protocols));
472 	}
473 
474 	/**
475 	 * This sets the certificate that @conn will present to its peer
476 	 * during the TLS handshake. For a #GTlsServerConnection, it is
477 	 * mandatory to set this, and that will normally be done at construct
478 	 * time.
479 	 *
480 	 * For a #GTlsClientConnection, this is optional. If a handshake fails
481 	 * with %G_TLS_ERROR_CERTIFICATE_REQUIRED, that means that the server
482 	 * requires a certificate, and if you try connecting again, you should
483 	 * call this method first. You can call
484 	 * g_tls_client_connection_get_accepted_cas() on the failed connection
485 	 * to get a list of Certificate Authorities that the server will
486 	 * accept certificates from.
487 	 *
488 	 * (It is also possible that a server will allow the connection with
489 	 * or without a certificate; in that case, if you don't provide a
490 	 * certificate, you can tell that the server requested one by the fact
491 	 * that g_tls_client_connection_get_accepted_cas() will return
492 	 * non-%NULL.)
493 	 *
494 	 * Params:
495 	 *     certificate = the certificate to use for @conn
496 	 *
497 	 * Since: 2.28
498 	 */
499 	public void setCertificate(TlsCertificate certificate)
500 	{
501 		g_tls_connection_set_certificate(gTlsConnection, (certificate is null) ? null : certificate.getTlsCertificateStruct());
502 	}
503 
504 	/**
505 	 * Sets the certificate database that is used to verify peer certificates.
506 	 * This is set to the default database by default. See
507 	 * g_tls_backend_get_default_database(). If set to %NULL, then
508 	 * peer certificate validation will always set the
509 	 * %G_TLS_CERTIFICATE_UNKNOWN_CA error (meaning
510 	 * #GTlsConnection::accept-certificate will always be emitted on
511 	 * client-side connections, unless that bit is not set in
512 	 * #GTlsClientConnection:validation-flags).
513 	 *
514 	 * There are nonintuitive security implications when using a non-default
515 	 * database. See #GDtlsConnection:database for details.
516 	 *
517 	 * Params:
518 	 *     database = a #GTlsDatabase
519 	 *
520 	 * Since: 2.30
521 	 */
522 	public void setDatabase(TlsDatabase database)
523 	{
524 		g_tls_connection_set_database(gTlsConnection, (database is null) ? null : database.getTlsDatabaseStruct());
525 	}
526 
527 	/**
528 	 * Set the object that will be used to interact with the user. It will be used
529 	 * for things like prompting the user for passwords.
530 	 *
531 	 * The @interaction argument will normally be a derived subclass of
532 	 * #GTlsInteraction. %NULL can also be provided if no user interaction
533 	 * should occur for this connection.
534 	 *
535 	 * Params:
536 	 *     interaction = an interaction object, or %NULL
537 	 *
538 	 * Since: 2.30
539 	 */
540 	public void setInteraction(TlsInteraction interaction)
541 	{
542 		g_tls_connection_set_interaction(gTlsConnection, (interaction is null) ? null : interaction.getTlsInteractionStruct());
543 	}
544 
545 	/**
546 	 * Since GLib 2.64, changing the rehandshake mode is no longer supported
547 	 * and will have no effect. With TLS 1.3, rehandshaking has been removed from
548 	 * the TLS protocol, replaced by separate post-handshake authentication and
549 	 * rekey operations.
550 	 *
551 	 * Deprecated: Changing the rehandshake mode is no longer
552 	 * required for compatibility. Also, rehandshaking has been removed
553 	 * from the TLS protocol in TLS 1.3.
554 	 *
555 	 * Params:
556 	 *     mode = the rehandshaking mode
557 	 *
558 	 * Since: 2.28
559 	 */
560 	public void setRehandshakeMode(GTlsRehandshakeMode mode)
561 	{
562 		g_tls_connection_set_rehandshake_mode(gTlsConnection, mode);
563 	}
564 
565 	/**
566 	 * Sets whether or not @conn expects a proper TLS close notification
567 	 * before the connection is closed. If this is %TRUE (the default),
568 	 * then @conn will expect to receive a TLS close notification from its
569 	 * peer before the connection is closed, and will return a
570 	 * %G_TLS_ERROR_EOF error if the connection is closed without proper
571 	 * notification (since this may indicate a network error, or
572 	 * man-in-the-middle attack).
573 	 *
574 	 * In some protocols, the application will know whether or not the
575 	 * connection was closed cleanly based on application-level data
576 	 * (because the application-level data includes a length field, or is
577 	 * somehow self-delimiting); in this case, the close notify is
578 	 * redundant and sometimes omitted. (TLS 1.1 explicitly allows this;
579 	 * in TLS 1.0 it is technically an error, but often done anyway.) You
580 	 * can use g_tls_connection_set_require_close_notify() to tell @conn
581 	 * to allow an "unannounced" connection close, in which case the close
582 	 * will show up as a 0-length read, as in a non-TLS
583 	 * #GSocketConnection, and it is up to the application to check that
584 	 * the data has been fully received.
585 	 *
586 	 * Note that this only affects the behavior when the peer closes the
587 	 * connection; when the application calls g_io_stream_close() itself
588 	 * on @conn, this will send a close notification regardless of the
589 	 * setting of this property. If you explicitly want to do an unclean
590 	 * close, you can close @conn's #GTlsConnection:base-io-stream rather
591 	 * than closing @conn itself, but note that this may only be done when no other
592 	 * operations are pending on @conn or the base I/O stream.
593 	 *
594 	 * Params:
595 	 *     requireCloseNotify = whether or not to require close notification
596 	 *
597 	 * Since: 2.28
598 	 */
599 	public void setRequireCloseNotify(bool requireCloseNotify)
600 	{
601 		g_tls_connection_set_require_close_notify(gTlsConnection, requireCloseNotify);
602 	}
603 
604 	/**
605 	 * Sets whether @conn uses the system certificate database to verify
606 	 * peer certificates. This is %TRUE by default. If set to %FALSE, then
607 	 * peer certificate validation will always set the
608 	 * %G_TLS_CERTIFICATE_UNKNOWN_CA error (meaning
609 	 * #GTlsConnection::accept-certificate will always be emitted on
610 	 * client-side connections, unless that bit is not set in
611 	 * #GTlsClientConnection:validation-flags).
612 	 *
613 	 * Deprecated: Use g_tls_connection_set_database() instead
614 	 *
615 	 * Params:
616 	 *     useSystemCertdb = whether to use the system certificate database
617 	 */
618 	public void setUseSystemCertdb(bool useSystemCertdb)
619 	{
620 		g_tls_connection_set_use_system_certdb(gTlsConnection, useSystemCertdb);
621 	}
622 
623 	/**
624 	 * Emitted during the TLS handshake after the peer certificate has
625 	 * been received. You can examine @peer_cert's certification path by
626 	 * calling g_tls_certificate_get_issuer() on it.
627 	 *
628 	 * For a client-side connection, @peer_cert is the server's
629 	 * certificate, and the signal will only be emitted if the
630 	 * certificate was not acceptable according to @conn's
631 	 * #GTlsClientConnection:validation_flags. If you would like the
632 	 * certificate to be accepted despite @errors, return %TRUE from the
633 	 * signal handler. Otherwise, if no handler accepts the certificate,
634 	 * the handshake will fail with %G_TLS_ERROR_BAD_CERTIFICATE.
635 	 *
636 	 * GLib guarantees that if certificate verification fails, this signal
637 	 * will be emitted with at least one error will be set in @errors, but
638 	 * it does not guarantee that all possible errors will be set.
639 	 * Accordingly, you may not safely decide to ignore any particular
640 	 * type of error. For example, it would be incorrect to ignore
641 	 * %G_TLS_CERTIFICATE_EXPIRED if you want to allow expired
642 	 * certificates, because this could potentially be the only error flag
643 	 * set even if other problems exist with the certificate.
644 	 *
645 	 * For a server-side connection, @peer_cert is the certificate
646 	 * presented by the client, if this was requested via the server's
647 	 * #GTlsServerConnection:authentication_mode. On the server side,
648 	 * the signal is always emitted when the client presents a
649 	 * certificate, and the certificate will only be accepted if a
650 	 * handler returns %TRUE.
651 	 *
652 	 * Note that if this signal is emitted as part of asynchronous I/O
653 	 * in the main thread, then you should not attempt to interact with
654 	 * the user before returning from the signal handler. If you want to
655 	 * let the user decide whether or not to accept the certificate, you
656 	 * would have to return %FALSE from the signal handler on the first
657 	 * attempt, and then after the connection attempt returns a
658 	 * %G_TLS_ERROR_BAD_CERTIFICATE, you can interact with the user, and
659 	 * if the user decides to accept the certificate, remember that fact,
660 	 * create a new connection, and return %TRUE from the signal handler
661 	 * the next time.
662 	 *
663 	 * If you are doing I/O in another thread, you do not
664 	 * need to worry about this, and can simply block in the signal
665 	 * handler until the UI thread returns an answer.
666 	 *
667 	 * Params:
668 	 *     peerCert = the peer's #GTlsCertificate
669 	 *     errors = the problems with @peer_cert.
670 	 *
671 	 * Returns: %TRUE to accept @peer_cert (which will also
672 	 *     immediately end the signal emission). %FALSE to allow the signal
673 	 *     emission to continue, which will cause the handshake to fail if
674 	 *     no one else overrides it.
675 	 *
676 	 * Since: 2.28
677 	 */
678 	gulong addOnAcceptCertificate(bool delegate(TlsCertificate, GTlsCertificateFlags, TlsConnection) dlg, ConnectFlags connectFlags=cast(ConnectFlags)0)
679 	{
680 		return Signals.connect(this, "accept-certificate", dlg, connectFlags ^ ConnectFlags.SWAPPED);
681 	}
682 }