/* GIO - GLib Input, Output and Streaming Library

 *

 * Copyright (C) 2011 Collabora, Ltd.

 *

 * SPDX-License-Identifier: LGPL-2.1-or-later

 *

 * 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/>.

 *

 * Author: Stef Walter <stefw@collabora.co.uk>

 */

#include "config.h"

#include <string.h>

#include "gtlscertificate.h"

#include "gtlsconnection.h"

#include "gtlsinteraction.h"

#include "gtlspassword.h"

#include "gasyncresult.h"

#include "gcancellable.h"

#include "gtask.h"

#include "gioenumtypes.h"

#include "glibintl.h"

/**

 * SECTION:gtlsinteraction

 * @short_description: Interaction with the user during TLS operations.

 * @include: gio/gio.h

 *

 * #GTlsInteraction provides a mechanism for the TLS connection and database

 * code to interact with the user. It can be used to ask the user for passwords.

 *

 * To use a #GTlsInteraction with a TLS connection use

 * g_tls_connection_set_interaction().

 *

 * Callers should instantiate a derived class that implements the various

 * interaction methods to show the required dialogs.

 *

 * Callers should use the 'invoke' functions like

 * g_tls_interaction_invoke_ask_password() to run interaction methods. These

 * functions make sure that the interaction is invoked in the main loop

 * and not in the current thread, if the current thread is not running the

 * main loop.

 *

 * Derived classes can choose to implement whichever interactions methods they'd

 * like to support by overriding those virtual methods in their class

 * initialization function. Any interactions not implemented will return

 * %G_TLS_INTERACTION_UNHANDLED. If a derived class implements an async method,

 * it must also implement the corresponding finish method.

 */

/**

 * GTlsInteraction:

 *

 * An object representing interaction that the TLS connection and database

 * might have with the user.

 *

 * Since: 2.30

 */

/**

 * GTlsInteractionClass:

 * @ask_password: ask for a password synchronously. If the implementation

 *     returns %G_TLS_INTERACTION_HANDLED, then the password argument should

 *     have been filled in by using g_tls_password_set_value() or a similar

 *     function.

 * @ask_password_async: ask for a password asynchronously.

 * @ask_password_finish: complete operation to ask for a password asynchronously.

 *     If the implementation returns %G_TLS_INTERACTION_HANDLED, then the

 *     password argument of the async method should have been filled in by using

 *     g_tls_password_set_value() or a similar function.

 * @request_certificate: ask for a certificate synchronously. If the

 *     implementation returns %G_TLS_INTERACTION_HANDLED, then the connection

 *     argument should have been filled in by using

 *     g_tls_connection_set_certificate().

 * @request_certificate_async: ask for a certificate asynchronously.

 * @request_certificate_finish: complete operation to ask for a certificate

 *     asynchronously. If the implementation returns %G_TLS_INTERACTION_HANDLED,

 *     then the connection argument of the async method should have been

 *     filled in by using g_tls_connection_set_certificate().

 *

 * The class for #GTlsInteraction. Derived classes implement the various

 * virtual interaction methods to handle TLS interactions.

 *

 * Derived classes can choose to implement whichever interactions methods they'd

 * like to support by overriding those virtual methods in their class

 * initialization function. If a derived class implements an async method,

 * it must also implement the corresponding finish method.

 *

 * The synchronous interaction methods should implement to display modal dialogs,

 * and the asynchronous methods to display modeless dialogs.

 *

 * If the user cancels an interaction, then the result should be

 * %G_TLS_INTERACTION_FAILED and the error should be set with a domain of

 * %G_IO_ERROR and code of %G_IO_ERROR_CANCELLED.

 *

 * Since: 2.30

 */

struct _GTlsInteractionPrivate {

  GMainContext *context;

};

G_DEFINE_TYPE_WITH_PRIVATE (GTlsInteraction, g_tls_interaction, G_TYPE_OBJECT)

typedef struct {

  GMutex mutex;

  /* Input arguments */

  GTlsInteraction *interaction;

  GObject *argument;

  GCancellable *cancellable;

  /* Used when we're invoking async interactions */

  GAsyncReadyCallback callback;

  gpointer user_data;

  /* Used when we expect results */

  GTlsInteractionResult result;

  GError *error;

  gboolean complete;

  GCond cond;

} InvokeClosure;

static void

invoke_closure_free (gpointer data)

{

  InvokeClosure *closure = data;

  g_assert (closure);

  g_object_unref (closure->interaction);

  g_clear_object (&closure->argument);

  g_clear_object (&closure->cancellable);

  g_cond_clear (&closure->cond);

  g_mutex_clear (&closure->mutex);

  g_clear_error (&closure->error);

  /* Insurance that we've actually used these before freeing */

  g_assert (closure->callback == NULL);

  g_assert (closure->user_data == NULL);

  g_free (closure);

}

static InvokeClosure *

invoke_closure_new (GTlsInteraction *interaction,

                    GObject         *argument,

                    GCancellable    *cancellable)

{

  InvokeClosure *closure = g_new0 (InvokeClosure, 1);

  closure->interaction = g_object_ref (interaction);

  closure->argument = argument ? g_object_ref (argument) : NULL;

  closure->cancellable = cancellable ? g_object_ref (cancellable) : NULL;

  g_mutex_init (&closure->mutex);

  g_cond_init (&closure->cond);

  closure->result = G_TLS_INTERACTION_UNHANDLED;

  return closure;

}

static GTlsInteractionResult

invoke_closure_wait_and_free (InvokeClosure *closure,

                              GError       **error)

{

  GTlsInteractionResult result;

  g_mutex_lock (&closure->mutex);

  while (!closure->complete)

    g_cond_wait (&closure->cond, &closure->mutex);

  g_mutex_unlock (&closure->mutex);

  if (closure->error)

    {

      g_propagate_error (error, closure->error);

      closure->error = NULL;

    }

  result = closure->result;

  invoke_closure_free (closure);

  return result;

}

static GTlsInteractionResult

invoke_closure_complete_and_free (GTlsInteraction *interaction,

                                  InvokeClosure *closure,

                                  GError **error)

{

  GTlsInteractionResult result;

  gboolean complete;

  /*

   * Handle the case where we've been called from within the main context

   * or in the case where the main context is not running. This approximates

   * the behavior of a modal dialog.

   */

  if (g_main_context_acquire (interaction->priv->context))

    {

      for (;;)

        {

          g_mutex_lock (&closure->mutex);

          complete = closure->complete;

          g_mutex_unlock (&closure->mutex);

          if (complete)

            break;

          g_main_context_iteration (interaction->priv->context, TRUE);

        }

      g_main_context_release (interaction->priv->context);

      if (closure->error)

        {

          g_propagate_error (error, closure->error);

          closure->error = NULL;

        }

      result = closure->result;

      invoke_closure_free (closure);

    }

  /*

   * Handle the case where we're in a different thread than the main

   * context and a main loop is running.

   */

  else

    {

      result = invoke_closure_wait_and_free (closure, error);

    }

  return result;

}

static void

g_tls_interaction_init (GTlsInteraction *interaction)

{

  interaction->priv = g_tls_interaction_get_instance_private (interaction);

  interaction->priv->context = g_main_context_ref_thread_default ();

}

static void

g_tls_interaction_finalize (GObject *object)

{

  GTlsInteraction *interaction = G_TLS_INTERACTION (object);

  g_main_context_unref (interaction->priv->context);

  G_OBJECT_CLASS (g_tls_interaction_parent_class)->finalize (object);

}

static void

g_tls_interaction_class_init (GTlsInteractionClass *klass)

{

  GObjectClass *gobject_class = G_OBJECT_CLASS (klass);

  gobject_class->finalize = g_tls_interaction_finalize;

}

static gboolean

on_invoke_ask_password_sync (gpointer user_data)

{

  InvokeClosure *closure = user_data;

  GTlsInteractionClass *klass;

  g_mutex_lock (&closure->mutex);

  klass = G_TLS_INTERACTION_GET_CLASS (closure->interaction);

  g_assert (klass->ask_password);

  closure->result = klass->ask_password (closure->interaction,

                                         G_TLS_PASSWORD (closure->argument),

                                         closure->cancellable,

                                         &closure->error);

  closure->complete = TRUE;

  g_cond_signal (&closure->cond);

  g_mutex_unlock (&closure->mutex);

  return FALSE; /* don't call again */

}

static void

on_ask_password_complete (GObject      *source,

                          GAsyncResult *result,

                          gpointer      user_data)

{

  InvokeClosure *closure = user_data;

  GTlsInteractionClass *klass;

  g_mutex_lock (&closure->mutex);

  klass = G_TLS_INTERACTION_GET_CLASS (closure->interaction);

  g_assert (klass->ask_password_finish);

  closure->result = klass->ask_password_finish (closure->interaction,

                                                result,

                                                &closure->error);

  closure->complete = TRUE;

  g_cond_signal (&closure->cond);

  g_mutex_unlock (&closure->mutex);

}

static gboolean

on_invoke_ask_password_async_as_sync (gpointer user_data)

{

  InvokeClosure *closure = user_data;

  GTlsInteractionClass *klass;

  g_mutex_lock (&closure->mutex);

  klass = G_TLS_INTERACTION_GET_CLASS (closure->interaction);

  g_assert (klass->ask_password_async);

  klass->ask_password_async (closure->interaction,

                             G_TLS_PASSWORD (closure->argument),

                             closure->cancellable,

                             on_ask_password_complete,

                             closure);

  /* Note that we've used these */

  closure->callback = NULL;

  closure->user_data = NULL;

  g_mutex_unlock (&closure->mutex);

  return FALSE; /* don't call again */

}

/**

 * g_tls_interaction_invoke_ask_password:

 * @interaction: a #GTlsInteraction object

 * @password: a #GTlsPassword object

 * @cancellable: an optional #GCancellable cancellation object

 * @error: an optional location to place an error on failure

 *

 * Invoke the interaction to ask the user for a password. It invokes this

 * interaction in the main loop, specifically the #GMainContext returned by

 * g_main_context_get_thread_default() when the interaction is created. This

 * is called by called by #GTlsConnection or #GTlsDatabase to ask the user

 * for a password.

 *

 * Derived subclasses usually implement a password prompt, although they may

 * also choose to provide a password from elsewhere. The @password value will

 * be filled in and then @callback will be called. Alternatively the user may

 * abort this password request, which will usually abort the TLS connection.

 *

 * The implementation can either be a synchronous (eg: modal dialog) or an

 * asynchronous one (eg: modeless dialog). This function will take care of

 * calling which ever one correctly.

 *

 * If the interaction is cancelled by the cancellation object, or by the

 * user then %G_TLS_INTERACTION_FAILED will be returned with an error that

 * contains a %G_IO_ERROR_CANCELLED error code. Certain implementations may

 * not support immediate cancellation.

 *

 * Returns: The status of the ask password interaction.

 *

 * Since: 2.30

 */

GTlsInteractionResult

g_tls_interaction_invoke_ask_password (GTlsInteraction    *interaction,

                                       GTlsPassword       *password,

                                       GCancellable       *cancellable,

                                       GError            **error)

{

  GTlsInteractionResult result;

  InvokeClosure *closure;

  GTlsInteractionClass *klass;

  g_return_val_if_fail (G_IS_TLS_INTERACTION (interaction), G_TLS_INTERACTION_UNHANDLED);

  g_return_val_if_fail (G_IS_TLS_PASSWORD (password), G_TLS_INTERACTION_UNHANDLED);

  g_return_val_if_fail (cancellable == NULL || G_IS_CANCELLABLE (cancellable), G_TLS_INTERACTION_UNHANDLED);

  klass = G_TLS_INTERACTION_GET_CLASS (interaction);

  if (klass->ask_password)

    {

      closure = invoke_closure_new (interaction, G_OBJECT (password), cancellable);

      g_main_context_invoke (interaction->priv->context,

                             on_invoke_ask_password_sync, closure);

      result = invoke_closure_wait_and_free (closure, error);

    }

  else if (klass->ask_password_async)

    {

      g_return_val_if_fail (klass->ask_password_finish, G_TLS_INTERACTION_UNHANDLED);

      closure = invoke_closure_new (interaction, G_OBJECT (password), cancellable);

      g_main_context_invoke (interaction->priv->context,

                             on_invoke_ask_password_async_as_sync, closure);

      result = invoke_closure_complete_and_free (interaction, closure, error);

    }

  else

    {

      result = G_TLS_INTERACTION_UNHANDLED;

    }

  return result;

}

/**

 * g_tls_interaction_ask_password:

 * @interaction: a #GTlsInteraction object

 * @password: a #GTlsPassword object

 * @cancellable: an optional #GCancellable cancellation object

 * @error: an optional location to place an error on failure

 *

 * Run synchronous interaction to ask the user for a password. In general,

 * g_tls_interaction_invoke_ask_password() should be used instead of this

 * function.

 *

 * Derived subclasses usually implement a password prompt, although they may

 * also choose to provide a password from elsewhere. The @password value will

 * be filled in and then @callback will be called. Alternatively the user may

 * abort this password request, which will usually abort the TLS connection.

 *

 * If the interaction is cancelled by the cancellation object, or by the

 * user then %G_TLS_INTERACTION_FAILED will be returned with an error that

 * contains a %G_IO_ERROR_CANCELLED error code. Certain implementations may

 * not support immediate cancellation.

 *

 * Returns: The status of the ask password interaction.

 *

 * Since: 2.30

 */

GTlsInteractionResult

g_tls_interaction_ask_password (GTlsInteraction    *interaction,

                                GTlsPassword       *password,

                                GCancellable       *cancellable,

                                GError            **error)

{

  GTlsInteractionClass *klass;

  g_return_val_if_fail (G_IS_TLS_INTERACTION (interaction), G_TLS_INTERACTION_UNHANDLED);

  g_return_val_if_fail (G_IS_TLS_PASSWORD (password), G_TLS_INTERACTION_UNHANDLED);

  g_return_val_if_fail (cancellable == NULL || G_IS_CANCELLABLE (cancellable), G_TLS_INTERACTION_UNHANDLED);

  klass = G_TLS_INTERACTION_GET_CLASS (interaction);

  if (klass->ask_password)

    return (klass->ask_password) (interaction, password, cancellable, error);

  else

    return G_TLS_INTERACTION_UNHANDLED;

}

/**

 * g_tls_interaction_ask_password_async:

 * @interaction: a #GTlsInteraction object

 * @password: a #GTlsPassword object

 * @cancellable: an optional #GCancellable cancellation object

 * @callback: (nullable): will be called when the interaction completes

 * @user_data: (nullable): data to pass to the @callback

 *

 * Run asynchronous interaction to ask the user for a password. In general,

 * g_tls_interaction_invoke_ask_password() should be used instead of this

 * function.

 *

 * Derived subclasses usually implement a password prompt, although they may

 * also choose to provide a password from elsewhere. The @password value will

 * be filled in and then @callback will be called. Alternatively the user may

 * abort this password request, which will usually abort the TLS connection.

 *

 * If the interaction is cancelled by the cancellation object, or by the

 * user then %G_TLS_INTERACTION_FAILED will be returned with an error that

 * contains a %G_IO_ERROR_CANCELLED error code. Certain implementations may

 * not support immediate cancellation.

 *

 * Certain implementations may not support immediate cancellation.

 *

 * Since: 2.30

 */

void

g_tls_interaction_ask_password_async (GTlsInteraction    *interaction,

                                      GTlsPassword       *password,

                                      GCancellable       *cancellable,

                                      GAsyncReadyCallback callback,

                                      gpointer            user_data)

{

  GTlsInteractionClass *klass;

  GTask *task;

  g_return_if_fail (G_IS_TLS_INTERACTION (interaction));

  g_return_if_fail (G_IS_TLS_PASSWORD (password));

  g_return_if_fail (cancellable == NULL || G_IS_CANCELLABLE (cancellable));

  klass = G_TLS_INTERACTION_GET_CLASS (interaction);

  if (klass->ask_password_async)

    {

      g_return_if_fail (klass->ask_password_finish);

      (klass->ask_password_async) (interaction, password, cancellable,

                                   callback, user_data);

    }

  else

    {

      task = g_task_new (interaction, cancellable, callback, user_data);

      g_task_set_source_tag (task, g_tls_interaction_ask_password_async);

      g_task_return_int (task, G_TLS_INTERACTION_UNHANDLED);

      g_object_unref (task);

    }

}

/**

 * g_tls_interaction_ask_password_finish:

 * @interaction: a #GTlsInteraction object

 * @result: the result passed to the callback

 * @error: an optional location to place an error on failure

 *

 * Complete an ask password user interaction request. This should be once

 * the g_tls_interaction_ask_password_async() completion callback is called.

 *

 * If %G_TLS_INTERACTION_HANDLED is returned, then the #GTlsPassword passed

 * to g_tls_interaction_ask_password() will have its password filled in.

 *

 * If the interaction is cancelled by the cancellation object, or by the

 * user then %G_TLS_INTERACTION_FAILED will be returned with an error that

 * contains a %G_IO_ERROR_CANCELLED error code.

 *

 * Returns: The status of the ask password interaction.

 *

 * Since: 2.30

 */

GTlsInteractionResult

g_tls_interaction_ask_password_finish (GTlsInteraction    *interaction,

                                       GAsyncResult       *result,

                                       GError            **error)

{

  GTlsInteractionClass *klass;

  g_return_val_if_fail (G_IS_TLS_INTERACTION (interaction), G_TLS_INTERACTION_UNHANDLED);

  g_return_val_if_fail (G_IS_ASYNC_RESULT (result), G_TLS_INTERACTION_UNHANDLED);

  klass = G_TLS_INTERACTION_GET_CLASS (interaction);

  if (klass->ask_password_finish)

    {

      g_return_val_if_fail (klass->ask_password_async != NULL, G_TLS_INTERACTION_UNHANDLED);

      return (klass->ask_password_finish) (interaction, result, error);

    }

  else

    {

      g_return_val_if_fail (g_async_result_is_tagged (result, g_tls_interaction_ask_password_async), G_TLS_INTERACTION_UNHANDLED);

      return g_task_propagate_int (G_TASK (result), error);

    }

}

static gboolean

on_invoke_request_certificate_sync (gpointer user_data)

{

  InvokeClosure *closure = user_data;

  GTlsInteractionClass *klass;

  g_mutex_lock (&closure->mutex);

  klass = G_TLS_INTERACTION_GET_CLASS (closure->interaction);

  g_assert (klass->request_certificate != NULL);

  closure->result = klass->request_certificate (closure->interaction,

                                                G_TLS_CONNECTION (closure->argument),

                                                0,

                                                closure->cancellable,

                                                &closure->error);

  closure->complete = TRUE;

  g_cond_signal (&closure->cond);

  g_mutex_unlock (&closure->mutex);

  return FALSE; /* don't call again */

}

static void

on_request_certificate_complete (GObject      *source,

                                 GAsyncResult *result,

                                 gpointer      user_data)

{

  InvokeClosure *closure = user_data;

  GTlsInteractionClass *klass;

  g_mutex_lock (&closure->mutex);

  klass = G_TLS_INTERACTION_GET_CLASS (closure->interaction);

  g_assert (klass->request_certificate_finish != NULL);

  closure->result = klass->request_certificate_finish (closure->interaction,

                                                       result, &closure->error);

  closure->complete = TRUE;

  g_cond_signal (&closure->cond);

  g_mutex_unlock (&closure->mutex);

}

static gboolean

on_invoke_request_certificate_async_as_sync (gpointer user_data)

{

  InvokeClosure *closure = user_data;

  GTlsInteractionClass *klass;

  g_mutex_lock (&closure->mutex);

  klass = G_TLS_INTERACTION_GET_CLASS (closure->interaction);

  g_assert (klass->request_certificate_async);

  klass->request_certificate_async (closure->interaction,

                                    G_TLS_CONNECTION (closure->argument), 0,

                                    closure->cancellable,

                                    on_request_certificate_complete,

                                    closure);

  /* Note that we've used these */

  closure->callback = NULL;

  closure->user_data = NULL;

  g_mutex_unlock (&closure->mutex);

  return FALSE; /* don't call again */

}

/**

 * g_tls_interaction_invoke_request_certificate:

 * @interaction: a #GTlsInteraction object

 * @connection: a #GTlsConnection object

 * @flags: flags providing more information about the request

 * @cancellable: an optional #GCancellable cancellation object

 * @error: an optional location to place an error on failure

 *

 * Invoke the interaction to ask the user to choose a certificate to

 * use with the connection. It invokes this interaction in the main

 * loop, specifically the #GMainContext returned by

 * g_main_context_get_thread_default() when the interaction is

 * created. This is called by called by #GTlsConnection when the peer

 * requests a certificate during the handshake.

 *

 * Derived subclasses usually implement a certificate selector,

 * although they may also choose to provide a certificate from

 * elsewhere. Alternatively the user may abort this certificate

 * request, which may or may not abort the TLS connection.

 *

 * The implementation can either be a synchronous (eg: modal dialog) or an

 * asynchronous one (eg: modeless dialog). This function will take care of

 * calling which ever one correctly.

 *

 * If the interaction is cancelled by the cancellation object, or by the

 * user then %G_TLS_INTERACTION_FAILED will be returned with an error that

 * contains a %G_IO_ERROR_CANCELLED error code. Certain implementations may

 * not support immediate cancellation.

 *

 * Returns: The status of the certificate request interaction.

 *

 * Since: 2.40

 */

GTlsInteractionResult

g_tls_interaction_invoke_request_certificate (GTlsInteraction    *interaction,

                                              GTlsConnection               *connection,

                                              GTlsCertificateRequestFlags   flags,

                                              GCancellable       *cancellable,

                                              GError            **error)

{

  GTlsInteractionResult result;

  InvokeClosure *closure;

  GTlsInteractionClass *klass;

  g_return_val_if_fail (G_IS_TLS_INTERACTION (interaction), G_TLS_INTERACTION_UNHANDLED);

  g_return_val_if_fail (G_IS_TLS_CONNECTION (connection), G_TLS_INTERACTION_UNHANDLED);

  g_return_val_if_fail (cancellable == NULL || G_IS_CANCELLABLE (cancellable), G_TLS_INTERACTION_UNHANDLED);

  klass = G_TLS_INTERACTION_GET_CLASS (interaction);

  if (klass->request_certificate)

    {

      closure = invoke_closure_new (interaction, G_OBJECT (connection), cancellable);

      g_main_context_invoke (interaction->priv->context,

                             on_invoke_request_certificate_sync, closure);

      result = invoke_closure_wait_and_free (closure, error);

    }

  else if (klass->request_certificate_async)

    {

      g_return_val_if_fail (klass->request_certificate_finish, G_TLS_INTERACTION_UNHANDLED);

      closure = invoke_closure_new (interaction, G_OBJECT (connection), cancellable);

      g_main_context_invoke (interaction->priv->context,

                             on_invoke_request_certificate_async_as_sync, closure);

      result = invoke_closure_complete_and_free (interaction, closure, error);

    }

  else

    {

      result = G_TLS_INTERACTION_UNHANDLED;

    }

  return result;

}

/**

 * g_tls_interaction_request_certificate:

 * @interaction: a #GTlsInteraction object

 * @connection: a #GTlsConnection object

 * @flags: flags providing more information about the request

 * @cancellable: an optional #GCancellable cancellation object

 * @error: an optional location to place an error on failure

 *

 * Run synchronous interaction to ask the user to choose a certificate to use

 * with the connection. In general, g_tls_interaction_invoke_request_certificate()

 * should be used instead of this function.

 *

 * Derived subclasses usually implement a certificate selector, although they may

 * also choose to provide a certificate from elsewhere. Alternatively the user may

 * abort this certificate request, which will usually abort the TLS connection.

 *

 * If %G_TLS_INTERACTION_HANDLED is returned, then the #GTlsConnection

 * passed to g_tls_interaction_request_certificate() will have had its

 * #GTlsConnection:certificate filled in.

 *

 * If the interaction is cancelled by the cancellation object, or by the

 * user then %G_TLS_INTERACTION_FAILED will be returned with an error that

 * contains a %G_IO_ERROR_CANCELLED error code. Certain implementations may

 * not support immediate cancellation.

 *

 * Returns: The status of the request certificate interaction.

 *

 * Since: 2.40

 */

GTlsInteractionResult

g_tls_interaction_request_certificate (GTlsInteraction              *interaction,

                                       GTlsConnection               *connection,

                                       GTlsCertificateRequestFlags   flags,

                                       GCancellable                 *cancellable,

                                       GError                      **error)

{

  GTlsInteractionClass *klass;

  g_return_val_if_fail (G_IS_TLS_INTERACTION (interaction), G_TLS_INTERACTION_UNHANDLED);

  g_return_val_if_fail (G_IS_TLS_CONNECTION (connection), G_TLS_INTERACTION_UNHANDLED);

  g_return_val_if_fail (cancellable == NULL || G_IS_CANCELLABLE (cancellable), G_TLS_INTERACTION_UNHANDLED);

  klass = G_TLS_INTERACTION_GET_CLASS (interaction);

  if (klass->request_certificate)

    return (klass->request_certificate) (interaction, connection, flags, cancellable, error);

  else

    return G_TLS_INTERACTION_UNHANDLED;

}

/**

 * g_tls_interaction_request_certificate_async:

 * @interaction: a #GTlsInteraction object

 * @connection: a #GTlsConnection object

 * @flags: flags providing more information about the request

 * @cancellable: an optional #GCancellable cancellation object

 * @callback: (nullable): will be called when the interaction completes

 * @user_data: (nullable): data to pass to the @callback

 *

 * Run asynchronous interaction to ask the user for a certificate to use with

 * the connection. In general, g_tls_interaction_invoke_request_certificate() should

 * be used instead of this function.

 *

 * Derived subclasses usually implement a certificate selector, although they may

 * also choose to provide a certificate from elsewhere. @callback will be called

 * when the operation completes. Alternatively the user may abort this certificate

 * request, which will usually abort the TLS connection.

 *

 * Since: 2.40

 */

void

g_tls_interaction_request_certificate_async (GTlsInteraction              *interaction,

                                             GTlsConnection               *connection,

                                             GTlsCertificateRequestFlags   flags,

                                             GCancellable                 *cancellable,

                                             GAsyncReadyCallback           callback,

                                             gpointer                      user_data)

{

  GTlsInteractionClass *klass;

  GTask *task;

  g_return_if_fail (G_IS_TLS_INTERACTION (interaction));

  g_return_if_fail (G_IS_TLS_CONNECTION (connection));

  g_return_if_fail (cancellable == NULL || G_IS_CANCELLABLE (cancellable));

  klass = G_TLS_INTERACTION_GET_CLASS (interaction);

  if (klass->request_certificate_async)

    {

      g_return_if_fail (klass->request_certificate_finish);

      (klass->request_certificate_async) (interaction, connection, flags,

                                          cancellable, callback, user_data);

    }

  else

    {

      task = g_task_new (interaction, cancellable, callback, user_data);

      g_task_set_source_tag (task, g_tls_interaction_request_certificate_async);

      g_task_return_int (task, G_TLS_INTERACTION_UNHANDLED);

      g_object_unref (task);

    }

}

/**

 * g_tls_interaction_request_certificate_finish:

 * @interaction: a #GTlsInteraction object

 * @result: the result passed to the callback

 * @error: an optional location to place an error on failure

 *

 * Complete a request certificate user interaction request. This should be once

 * the g_tls_interaction_request_certificate_async() completion callback is called.

 *

 * If %G_TLS_INTERACTION_HANDLED is returned, then the #GTlsConnection

 * passed to g_tls_interaction_request_certificate_async() will have had its

 * #GTlsConnection:certificate filled in.

 *

 * If the interaction is cancelled by the cancellation object, or by the

 * user then %G_TLS_INTERACTION_FAILED will be returned with an error that

 * contains a %G_IO_ERROR_CANCELLED error code.

 *

 * Returns: The status of the request certificate interaction.

 *

 * Since: 2.40

 */

GTlsInteractionResult

g_tls_interaction_request_certificate_finish (GTlsInteraction    *interaction,

                                              GAsyncResult       *result,

                                              GError            **error)

{

  GTlsInteractionClass *klass;

  g_return_val_if_fail (G_IS_TLS_INTERACTION (interaction), G_TLS_INTERACTION_UNHANDLED);

  g_return_val_if_fail (G_IS_ASYNC_RESULT (result), G_TLS_INTERACTION_UNHANDLED);

  klass = G_TLS_INTERACTION_GET_CLASS (interaction);

  if (klass->request_certificate_finish)

    {

      g_return_val_if_fail (klass->request_certificate_async != NULL, G_TLS_INTERACTION_UNHANDLED);

      return (klass->request_certificate_finish) (interaction, result, error);

    }

  else

    {

      g_return_val_if_fail (g_async_result_is_tagged (result, g_tls_interaction_request_certificate_async), G_TLS_INTERACTION_UNHANDLED);

      return g_task_propagate_int (G_TASK (result), error);

    }

}