/* GIO - GLib Input, Output and Streaming Library

 *

 * Copyright © 2010 Red Hat, Inc

 *

 * This library is free software; you can redistribute it and/or

 * modify it under the terms of the GNU Lesser General Public

 * License as published by the Free Software Foundation; either

 * version 2.1 of the License, or (at your option) any later version.

 *

 * This library is distributed in the hope that it will be useful,

 * but WITHOUT ANY WARRANTY; without even the implied warranty of

 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU

 * Lesser General Public License for more details.

 *

 * You should have received a copy of the GNU Lesser General

 * Public License along with this library; if not, see <http://www.gnu.org/licenses/>.

 */

#include "config.h"

#include "glib.h"

#include "gtlsconnection.h"

#include "gcancellable.h"

#include "gioenumtypes.h"

#include "gsocket.h"

#include "gtlsbackend.h"

#include "gtlscertificate.h"

#include "gtlsclientconnection.h"

#include "gtlsdatabase.h"

#include "gtlsinteraction.h"

#include "glibintl.h"

/**

 * SECTION:gtlsconnection

 * @short_description: TLS connection type

 * @include: gio/gio.h

 *

 * #GTlsConnection is the base TLS connection class type, which wraps

 * a #GIOStream and provides TLS encryption on top of it. Its

 * subclasses, #GTlsClientConnection and #GTlsServerConnection,

 * implement client-side and server-side TLS, respectively.

 *

 * For DTLS (Datagram TLS) support, see #GDtlsConnection.

 *

 * Since: 2.28

 */

/**

 * GTlsConnection:

 *

 * Abstract base class for the backend-specific #GTlsClientConnection

 * and #GTlsServerConnection types.

 *

 * Since: 2.28

 */

G_DEFINE_ABSTRACT_TYPE (GTlsConnection, g_tls_connection, G_TYPE_IO_STREAM)

static void g_tls_connection_get_property (GObject    *object,

					   guint       prop_id,

					   GValue     *value,

					   GParamSpec *pspec);

static void g_tls_connection_set_property (GObject      *object,

					   guint         prop_id,

					   const GValue *value,

					   GParamSpec   *pspec);

enum {

  ACCEPT_CERTIFICATE,

  LAST_SIGNAL

};

static guint signals[LAST_SIGNAL] = { 0 };

enum {

  PROP_0,

  PROP_BASE_IO_STREAM,

  PROP_REQUIRE_CLOSE_NOTIFY,

  PROP_REHANDSHAKE_MODE,

  PROP_USE_SYSTEM_CERTDB,

  PROP_DATABASE,

  PROP_INTERACTION,

  PROP_CERTIFICATE,

  PROP_PEER_CERTIFICATE,

  PROP_PEER_CERTIFICATE_ERRORS

};

static void

g_tls_connection_class_init (GTlsConnectionClass *klass)

{

  GObjectClass *gobject_class = G_OBJECT_CLASS (klass);

  gobject_class->get_property = g_tls_connection_get_property;

  gobject_class->set_property = g_tls_connection_set_property;

  /**

   * GTlsConnection:base-io-stream:

   *

   * The #GIOStream that the connection wraps. The connection holds a reference

   * to this stream, and may run operations on the stream from other threads

   * throughout its lifetime. Consequently, after the #GIOStream has been

   * constructed, application code may only run its own operations on this

   * stream when no #GIOStream operations are running.

   *

   * Since: 2.28

   */

  g_object_class_install_property (gobject_class, PROP_BASE_IO_STREAM,

				   g_param_spec_object ("base-io-stream",

							P_("Base IOStream"),

							P_("The GIOStream that the connection wraps"),

							G_TYPE_IO_STREAM,

							G_PARAM_READWRITE |

							G_PARAM_CONSTRUCT_ONLY |

							G_PARAM_STATIC_STRINGS));

  /**

   * GTlsConnection:use-system-certdb:

   *

   * Whether or not the system certificate database will be used to

   * verify peer certificates. See

   * g_tls_connection_set_use_system_certdb().

   *

   * Deprecated: 2.30: Use GTlsConnection:database instead

   */

  g_object_class_install_property (gobject_class, PROP_USE_SYSTEM_CERTDB,

				   g_param_spec_boolean ("use-system-certdb",

							 P_("Use system certificate database"),

							 P_("Whether to verify peer certificates against the system certificate database"),

							 TRUE,

							 G_PARAM_READWRITE |

							 G_PARAM_CONSTRUCT |

							 G_PARAM_STATIC_STRINGS));

  /**

   * GTlsConnection:database:

   *

   * The certificate database to use when verifying this TLS connection.

   * If no certificate database is set, then the default database will be

   * used. See g_tls_backend_get_default_database().

   *

   * Since: 2.30

   */

  g_object_class_install_property (gobject_class, PROP_DATABASE,

				   g_param_spec_object ("database",

							 P_("Database"),

							 P_("Certificate database to use for looking up or verifying certificates"),

							 G_TYPE_TLS_DATABASE,

							 G_PARAM_READWRITE |

							 G_PARAM_STATIC_STRINGS));

  /**

   * GTlsConnection:interaction:

   *

   * A #GTlsInteraction object to be used when the connection or certificate

   * database need to interact with the user. This will be used to prompt the

   * user for passwords where necessary.

   *

   * Since: 2.30

   */

  g_object_class_install_property (gobject_class, PROP_INTERACTION,

                                   g_param_spec_object ("interaction",

                                                        P_("Interaction"),

                                                        P_("Optional object for user interaction"),

                                                        G_TYPE_TLS_INTERACTION,

                                                        G_PARAM_READWRITE |

                                                        G_PARAM_STATIC_STRINGS));

  /**

   * GTlsConnection:require-close-notify:

   *

   * Whether or not proper TLS close notification is required.

   * See g_tls_connection_set_require_close_notify().

   *

   * Since: 2.28

   */

  g_object_class_install_property (gobject_class, PROP_REQUIRE_CLOSE_NOTIFY,

				   g_param_spec_boolean ("require-close-notify",

							 P_("Require close notify"),

							 P_("Whether to require proper TLS close notification"),

							 TRUE,

							 G_PARAM_READWRITE |

							 G_PARAM_CONSTRUCT |

							 G_PARAM_STATIC_STRINGS));

  /**

   * GTlsConnection:rehandshake-mode:

   *

   * The rehandshaking mode. See

   * g_tls_connection_set_rehandshake_mode().

   *

   * Since: 2.28

   */

  g_object_class_install_property (gobject_class, PROP_REHANDSHAKE_MODE,

				   g_param_spec_enum ("rehandshake-mode",

						      P_("Rehandshake mode"),

						      P_("When to allow rehandshaking"),

						      G_TYPE_TLS_REHANDSHAKE_MODE,

						      G_TLS_REHANDSHAKE_SAFELY,

						      G_PARAM_READWRITE |

						      G_PARAM_CONSTRUCT |

						      G_PARAM_STATIC_STRINGS));

  /**

   * GTlsConnection:certificate:

   *

   * The connection's certificate; see

   * g_tls_connection_set_certificate().

   *

   * Since: 2.28

   */

  g_object_class_install_property (gobject_class, PROP_CERTIFICATE,

				   g_param_spec_object ("certificate",

							P_("Certificate"),

							P_("The connection’s certificate"),

							G_TYPE_TLS_CERTIFICATE,

							G_PARAM_READWRITE |

							G_PARAM_STATIC_STRINGS));

  /**

   * GTlsConnection:peer-certificate:

   *

   * The connection's peer's certificate, after the TLS handshake has

   * completed and the certificate has been accepted. Note in

   * particular that this is not yet set during the emission of

   * #GTlsConnection::accept-certificate.

   *

   * (You can watch for a #GObject::notify signal on this property to

   * detect when a handshake has occurred.)

   *

   * Since: 2.28

   */

  g_object_class_install_property (gobject_class, PROP_PEER_CERTIFICATE,

				   g_param_spec_object ("peer-certificate",

							P_("Peer Certificate"),

							P_("The connection’s peer’s certificate"),

							G_TYPE_TLS_CERTIFICATE,

							G_PARAM_READABLE |

							G_PARAM_STATIC_STRINGS));

  /**

   * GTlsConnection:peer-certificate-errors:

   *

   * The errors noticed-and-ignored while verifying

   * #GTlsConnection:peer-certificate. Normally this should be 0, but

   * it may not be if #GTlsClientConnection:validation-flags is not

   * %G_TLS_CERTIFICATE_VALIDATE_ALL, or if

   * #GTlsConnection::accept-certificate overrode the default

   * behavior.

   *

   * Since: 2.28

   */

  g_object_class_install_property (gobject_class, PROP_PEER_CERTIFICATE_ERRORS,

				   g_param_spec_flags ("peer-certificate-errors",

						       P_("Peer Certificate Errors"),

						       P_("Errors found with the peer’s certificate"),

						       G_TYPE_TLS_CERTIFICATE_FLAGS,

						       0,

						       G_PARAM_READABLE |

						       G_PARAM_STATIC_STRINGS));

  /**

   * GTlsConnection::accept-certificate:

   * @conn: a #GTlsConnection

   * @peer_cert: the peer's #GTlsCertificate

   * @errors: the problems with @peer_cert.

   *

   * Emitted during the TLS handshake after the peer certificate has

   * been received. You can examine @peer_cert's certification path by

   * calling g_tls_certificate_get_issuer() on it.

   *

   * For a client-side connection, @peer_cert is the server's

   * certificate, and the signal will only be emitted if the

   * certificate was not acceptable according to @conn's

   * #GTlsClientConnection:validation_flags. If you would like the

   * certificate to be accepted despite @errors, return %TRUE from the

   * signal handler. Otherwise, if no handler accepts the certificate,

   * the handshake will fail with %G_TLS_ERROR_BAD_CERTIFICATE.

   *

   * For a server-side connection, @peer_cert is the certificate

   * presented by the client, if this was requested via the server's

   * #GTlsServerConnection:authentication_mode. On the server side,

   * the signal is always emitted when the client presents a

   * certificate, and the certificate will only be accepted if a

   * handler returns %TRUE.

   *

   * Note that if this signal is emitted as part of asynchronous I/O

   * in the main thread, then you should not attempt to interact with

   * the user before returning from the signal handler. If you want to

   * let the user decide whether or not to accept the certificate, you

   * would have to return %FALSE from the signal handler on the first

   * attempt, and then after the connection attempt returns a

   * %G_TLS_ERROR_HANDSHAKE, you can interact with the user, and if

   * the user decides to accept the certificate, remember that fact,

   * create a new connection, and return %TRUE from the signal handler

   * the next time.

   *

   * If you are doing I/O in another thread, you do not

   * need to worry about this, and can simply block in the signal

   * handler until the UI thread returns an answer.

   *

   * Returns: %TRUE to accept @peer_cert (which will also

   * immediately end the signal emission). %FALSE to allow the signal

   * emission to continue, which will cause the handshake to fail if

   * no one else overrides it.

   *

   * Since: 2.28

   */

  signals[ACCEPT_CERTIFICATE] =

    g_signal_new (I_("accept-certificate"),

		  G_TYPE_TLS_CONNECTION,

		  G_SIGNAL_RUN_LAST,

		  G_STRUCT_OFFSET (GTlsConnectionClass, accept_certificate),

		  g_signal_accumulator_true_handled, NULL,

		  NULL,

		  G_TYPE_BOOLEAN, 2,

		  G_TYPE_TLS_CERTIFICATE,

		  G_TYPE_TLS_CERTIFICATE_FLAGS);

}

static void

g_tls_connection_init (GTlsConnection *conn)

{

}

static void

g_tls_connection_get_property (GObject    *object,

			       guint       prop_id,

			       GValue     *value,

			       GParamSpec *pspec)

{

  G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);

}

static void

g_tls_connection_set_property (GObject      *object,

			       guint         prop_id,

			       const GValue *value,

			       GParamSpec   *pspec)

{

  G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);

}

/**

 * g_tls_connection_set_use_system_certdb:

 * @conn: a #GTlsConnection

 * @use_system_certdb: whether to use the system certificate database

 *

 * Sets whether @conn uses the system certificate database to verify

 * peer certificates. This is %TRUE by default. If set to %FALSE, then

 * peer certificate validation will always set the

 * %G_TLS_CERTIFICATE_UNKNOWN_CA error (meaning

 * #GTlsConnection::accept-certificate will always be emitted on

 * client-side connections, unless that bit is not set in

 * #GTlsClientConnection:validation-flags).

 *

 * Deprecated: 2.30: Use g_tls_connection_set_database() instead

 */

void

g_tls_connection_set_use_system_certdb (GTlsConnection *conn,

					gboolean        use_system_certdb)

{

  g_return_if_fail (G_IS_TLS_CONNECTION (conn));

  g_object_set (G_OBJECT (conn),

		"use-system-certdb", use_system_certdb,

		NULL);

}

/**

 * g_tls_connection_get_use_system_certdb:

 * @conn: a #GTlsConnection

 *

 * Gets whether @conn uses the system certificate database to verify

 * peer certificates. See g_tls_connection_set_use_system_certdb().

 *

 * Returns: whether @conn uses the system certificate database

 *

 * Deprecated: 2.30: Use g_tls_connection_get_database() instead

 */

gboolean

g_tls_connection_get_use_system_certdb (GTlsConnection *conn)

{

  gboolean use_system_certdb;

  g_return_val_if_fail (G_IS_TLS_CONNECTION (conn), TRUE);

  g_object_get (G_OBJECT (conn),

		"use-system-certdb", &use_system_certdb,

		NULL);

  return use_system_certdb;

}

/**

 * g_tls_connection_set_database:

 * @conn: a #GTlsConnection

 * @database: a #GTlsDatabase

 *

 * Sets the certificate database that is used to verify peer certificates.

 * This is set to the default database by default. See

 * g_tls_backend_get_default_database(). If set to %NULL, then

 * peer certificate validation will always set the

 * %G_TLS_CERTIFICATE_UNKNOWN_CA error (meaning

 * #GTlsConnection::accept-certificate will always be emitted on

 * client-side connections, unless that bit is not set in

 * #GTlsClientConnection:validation-flags).

 *

 * Since: 2.30

 */

void

g_tls_connection_set_database (GTlsConnection *conn,

                               GTlsDatabase   *database)

{

  g_return_if_fail (G_IS_TLS_CONNECTION (conn));

  g_return_if_fail (database == NULL || G_IS_TLS_DATABASE (database));

  g_object_set (G_OBJECT (conn),

		"database", database,

		NULL);

}

/**

 * g_tls_connection_get_database:

 * @conn: a #GTlsConnection

 *

 * Gets the certificate database that @conn uses to verify

 * peer certificates. See g_tls_connection_set_database().

 *

 * Returns: (transfer none): the certificate database that @conn uses or %NULL

 *

 * Since: 2.30

 */

GTlsDatabase*

g_tls_connection_get_database (GTlsConnection *conn)

{

  GTlsDatabase *database = NULL;

  g_return_val_if_fail (G_IS_TLS_CONNECTION (conn), NULL);

  g_object_get (G_OBJECT (conn),

		"database", &database,

		NULL);

  if (database)

    g_object_unref (database);

  return database;

}

/**

 * g_tls_connection_set_certificate:

 * @conn: a #GTlsConnection

 * @certificate: the certificate to use for @conn

 *

 * This sets the certificate that @conn will present to its peer

 * during the TLS handshake. For a #GTlsServerConnection, it is

 * mandatory to set this, and that will normally be done at construct

 * time.

 *

 * For a #GTlsClientConnection, this is optional. If a handshake fails

 * with %G_TLS_ERROR_CERTIFICATE_REQUIRED, that means that the server

 * requires a certificate, and if you try connecting again, you should

 * call this method first. You can call

 * g_tls_client_connection_get_accepted_cas() on the failed connection

 * to get a list of Certificate Authorities that the server will

 * accept certificates from.

 *

 * (It is also possible that a server will allow the connection with

 * or without a certificate; in that case, if you don't provide a

 * certificate, you can tell that the server requested one by the fact

 * that g_tls_client_connection_get_accepted_cas() will return

 * non-%NULL.)

 *

 * Since: 2.28

 */

void

g_tls_connection_set_certificate (GTlsConnection  *conn,

				  GTlsCertificate *certificate)

{

  g_return_if_fail (G_IS_TLS_CONNECTION (conn));

  g_return_if_fail (G_IS_TLS_CERTIFICATE (certificate));

  g_object_set (G_OBJECT (conn), "certificate", certificate, NULL);

}

/**

 * g_tls_connection_get_certificate:

 * @conn: a #GTlsConnection

 *

 * Gets @conn's certificate, as set by

 * g_tls_connection_set_certificate().

 *

 * Returns: (transfer none): @conn's certificate, or %NULL

 *

 * Since: 2.28

 */

GTlsCertificate *

g_tls_connection_get_certificate (GTlsConnection *conn)

{

  GTlsCertificate *certificate;

  g_return_val_if_fail (G_IS_TLS_CONNECTION (conn), NULL);

  g_object_get (G_OBJECT (conn), "certificate", &certificate, NULL);

  if (certificate)

    g_object_unref (certificate);

  return certificate;

}

/**

 * g_tls_connection_set_interaction:

 * @conn: a connection

 * @interaction: (nullable): an interaction object, or %NULL

 *

 * Set the object that will be used to interact with the user. It will be used

 * for things like prompting the user for passwords.

 *

 * The @interaction argument will normally be a derived subclass of

 * #GTlsInteraction. %NULL can also be provided if no user interaction

 * should occur for this connection.

 *

 * Since: 2.30

 */

void

g_tls_connection_set_interaction (GTlsConnection       *conn,

                                  GTlsInteraction      *interaction)

{

  g_return_if_fail (G_IS_TLS_CONNECTION (conn));

  g_return_if_fail (interaction == NULL || G_IS_TLS_INTERACTION (interaction));

  g_object_set (G_OBJECT (conn), "interaction", interaction, NULL);

}

/**

 * g_tls_connection_get_interaction:

 * @conn: a connection

 *

 * Get the object that will be used to interact with the user. It will be used

 * for things like prompting the user for passwords. If %NULL is returned, then

 * no user interaction will occur for this connection.

 *

 * Returns: (transfer none): The interaction object.

 *

 * Since: 2.30

 */

GTlsInteraction *

g_tls_connection_get_interaction (GTlsConnection       *conn)

{

  GTlsInteraction *interaction = NULL;

  g_return_val_if_fail (G_IS_TLS_CONNECTION (conn), NULL);

  g_object_get (G_OBJECT (conn), "interaction", &interaction, NULL);

  if (interaction)

    g_object_unref (interaction);

  return interaction;

}

/**

 * g_tls_connection_get_peer_certificate:

 * @conn: a #GTlsConnection

 *

 * Gets @conn's peer's certificate after the handshake has completed.

 * (It is not set during the emission of

 * #GTlsConnection::accept-certificate.)

 *

 * Returns: (transfer none): @conn's peer's certificate, or %NULL

 *

 * Since: 2.28

 */

GTlsCertificate *

g_tls_connection_get_peer_certificate (GTlsConnection *conn)

{

  GTlsCertificate *peer_certificate;

  g_return_val_if_fail (G_IS_TLS_CONNECTION (conn), NULL);

  g_object_get (G_OBJECT (conn), "peer-certificate", &peer_certificate, NULL);

  if (peer_certificate)

    g_object_unref (peer_certificate);

  return peer_certificate;

}

/**

 * g_tls_connection_get_peer_certificate_errors:

 * @conn: a #GTlsConnection

 *

 * Gets the errors associated with validating @conn's peer's

 * certificate, after the handshake has completed. (It is not set

 * during the emission of #GTlsConnection::accept-certificate.)

 *

 * Returns: @conn's peer's certificate errors

 *

 * Since: 2.28

 */

GTlsCertificateFlags

g_tls_connection_get_peer_certificate_errors (GTlsConnection *conn)

{

  GTlsCertificateFlags errors;

  g_return_val_if_fail (G_IS_TLS_CONNECTION (conn), 0);

  g_object_get (G_OBJECT (conn), "peer-certificate-errors", &errors, NULL);

  return errors;

}

/**

 * g_tls_connection_set_require_close_notify:

 * @conn: a #GTlsConnection

 * @require_close_notify: whether or not to require close notification

 *

 * Sets whether or not @conn expects a proper TLS close notification

 * before the connection is closed. If this is %TRUE (the default),

 * then @conn will expect to receive a TLS close notification from its

 * peer before the connection is closed, and will return a

 * %G_TLS_ERROR_EOF error if the connection is closed without proper

 * notification (since this may indicate a network error, or

 * man-in-the-middle attack).

 *

 * In some protocols, the application will know whether or not the

 * connection was closed cleanly based on application-level data

 * (because the application-level data includes a length field, or is

 * somehow self-delimiting); in this case, the close notify is

 * redundant and sometimes omitted. (TLS 1.1 explicitly allows this;

 * in TLS 1.0 it is technically an error, but often done anyway.) You

 * can use g_tls_connection_set_require_close_notify() to tell @conn

 * to allow an "unannounced" connection close, in which case the close

 * will show up as a 0-length read, as in a non-TLS

 * #GSocketConnection, and it is up to the application to check that

 * the data has been fully received.

 *

 * Note that this only affects the behavior when the peer closes the

 * connection; when the application calls g_io_stream_close() itself

 * on @conn, this will send a close notification regardless of the

 * setting of this property. If you explicitly want to do an unclean

 * close, you can close @conn's #GTlsConnection:base-io-stream rather

 * than closing @conn itself, but note that this may only be done when no other

 * operations are pending on @conn or the base I/O stream.

 *

 * Since: 2.28

 */

void

g_tls_connection_set_require_close_notify (GTlsConnection *conn,

					   gboolean        require_close_notify)

{

  g_return_if_fail (G_IS_TLS_CONNECTION (conn));

  g_object_set (G_OBJECT (conn),

		"require-close-notify", require_close_notify,

		NULL);

}

/**

 * g_tls_connection_get_require_close_notify:

 * @conn: a #GTlsConnection

 *

 * Tests whether or not @conn expects a proper TLS close notification

 * when the connection is closed. See

 * g_tls_connection_set_require_close_notify() for details.

 *

 * Returns: %TRUE if @conn requires a proper TLS close

 * notification.

 *

 * Since: 2.28

 */

gboolean

g_tls_connection_get_require_close_notify (GTlsConnection *conn)

{

  gboolean require_close_notify;

  g_return_val_if_fail (G_IS_TLS_CONNECTION (conn), TRUE);

  g_object_get (G_OBJECT (conn),

		"require-close-notify", &require_close_notify,

		NULL);

  return require_close_notify;

}

/**

 * g_tls_connection_set_rehandshake_mode:

 * @conn: a #GTlsConnection

 * @mode: the rehandshaking mode

 *

 * Sets how @conn behaves with respect to rehandshaking requests.

 *

 * %G_TLS_REHANDSHAKE_NEVER means that it will never agree to

 * rehandshake after the initial handshake is complete. (For a client,

 * this means it will refuse rehandshake requests from the server, and

 * for a server, this means it will close the connection with an error

 * if the client attempts to rehandshake.)

 *

 * %G_TLS_REHANDSHAKE_SAFELY means that the connection will allow a

 * rehandshake only if the other end of the connection supports the

 * TLS `renegotiation_info` extension. This is the default behavior,

 * but means that rehandshaking will not work against older

 * implementations that do not support that extension.

 *

 * %G_TLS_REHANDSHAKE_UNSAFELY means that the connection will allow

 * rehandshaking even without the `renegotiation_info` extension. On

 * the server side in particular, this is not recommended, since it

 * leaves the server open to certain attacks. However, this mode is

 * necessary if you need to allow renegotiation with older client

 * software.

 *

 * Since: 2.28

 */

void

g_tls_connection_set_rehandshake_mode (GTlsConnection       *conn,

				       GTlsRehandshakeMode   mode)

{

  g_return_if_fail (G_IS_TLS_CONNECTION (conn));

  g_object_set (G_OBJECT (conn),

		"rehandshake-mode", mode,

		NULL);

}

/**

 * g_tls_connection_get_rehandshake_mode:

 * @conn: a #GTlsConnection

 *

 * Gets @conn rehandshaking mode. See

 * g_tls_connection_set_rehandshake_mode() for details.

 *

 * Returns: @conn's rehandshaking mode

 *

 * Since: 2.28

 */

GTlsRehandshakeMode

g_tls_connection_get_rehandshake_mode (GTlsConnection       *conn)

{

  GTlsRehandshakeMode mode;

  g_return_val_if_fail (G_IS_TLS_CONNECTION (conn), G_TLS_REHANDSHAKE_NEVER);

  g_object_get (G_OBJECT (conn),

		"rehandshake-mode", &mode,

		NULL);

  return mode;

}

/**

 * g_tls_connection_handshake:

 * @conn: a #GTlsConnection

 * @cancellable: (nullable): a #GCancellable, or %NULL

 * @error: a #GError, or %NULL

 *

 * Attempts a TLS handshake on @conn.

 *

 * On the client side, it is never necessary to call this method;

 * although the connection needs to perform a handshake after

 * connecting (or after sending a "STARTTLS"-type command) and may

 * need to rehandshake later if the server requests it,

 * #GTlsConnection will handle this for you automatically when you try

 * to send or receive data on the connection. However, you can call

 * g_tls_connection_handshake() manually if you want to know for sure

 * whether the initial handshake succeeded or failed (as opposed to

 * just immediately trying to write to @conn's output stream, in which

 * case if it fails, it may not be possible to tell if it failed

 * before or after completing the handshake).

 *

 * Likewise, on the server side, although a handshake is necessary at

 * the beginning of the communication, you do not need to call this

 * function explicitly unless you want clearer error reporting.

 * However, you may call g_tls_connection_handshake() later on to

 * renegotiate parameters (encryption methods, etc) with the client.

 *

 * #GTlsConnection::accept_certificate may be emitted during the

 * handshake.

 *

 * Returns: success or failure

 *

 * Since: 2.28

 */

gboolean

g_tls_connection_handshake (GTlsConnection   *conn,

			    GCancellable     *cancellable,

			    GError          **error)

{

  g_return_val_if_fail (G_IS_TLS_CONNECTION (conn), FALSE);

  return G_TLS_CONNECTION_GET_CLASS (conn)->handshake (conn, cancellable, error);

}

/**

 * g_tls_connection_handshake_async:

 * @conn: a #GTlsConnection

 * @io_priority: the [I/O priority][io-priority] of the request

 * @cancellable: (nullable): a #GCancellable, or %NULL

 * @callback: callback to call when the handshake is complete

 * @user_data: the data to pass to the callback function

 *

 * Asynchronously performs a TLS handshake on @conn. See

 * g_tls_connection_handshake() for more information.

 *

 * Since: 2.28

 */

void

g_tls_connection_handshake_async (GTlsConnection       *conn,

				  int                   io_priority,

				  GCancellable         *cancellable,

				  GAsyncReadyCallback   callback,

				  gpointer              user_data)

{

  g_return_if_fail (G_IS_TLS_CONNECTION (conn));

  G_TLS_CONNECTION_GET_CLASS (conn)->handshake_async (conn, io_priority,

						      cancellable,

						      callback, user_data);

}

/**

 * g_tls_connection_handshake_finish:

 * @conn: a #GTlsConnection

 * @result: a #GAsyncResult.

 * @error: a #GError pointer, or %NULL

 *

 * Finish an asynchronous TLS handshake operation. See

 * g_tls_connection_handshake() for more information.

 *

 * Returns: %TRUE on success, %FALSE on failure, in which

 * case @error will be set.

 *

 * Since: 2.28

 */

gboolean

g_tls_connection_handshake_finish (GTlsConnection  *conn,

				   GAsyncResult    *result,

				   GError         **error)

{

  g_return_val_if_fail (G_IS_TLS_CONNECTION (conn), FALSE);

  return G_TLS_CONNECTION_GET_CLASS (conn)->handshake_finish (conn, result, error);

}

/**

 * g_tls_error_quark:

 *

 * Gets the TLS error quark.

 *

 * Returns: a #GQuark.

 *

 * Since: 2.28

 */

G_DEFINE_QUARK (g-tls-error-quark, g_tls_error)

/**

 * g_tls_connection_emit_accept_certificate:

 * @conn: a #GTlsConnection

 * @peer_cert: the peer's #GTlsCertificate

 * @errors: the problems with @peer_cert

 *

 * Used by #GTlsConnection implementations to emit the

 * #GTlsConnection::accept-certificate signal.

 *

 * Returns: %TRUE if one of the signal handlers has returned

 *     %TRUE to accept @peer_cert

 *

 * Since: 2.28

 */

gboolean

g_tls_connection_emit_accept_certificate (GTlsConnection       *conn,

					  GTlsCertificate      *peer_cert,

					  GTlsCertificateFlags  errors)

{

  gboolean accept = FALSE;

  g_signal_emit (conn, signals[ACCEPT_CERTIFICATE], 0,

		 peer_cert, errors, &accept);

  return accept;

}