gio/gtlsinteraction.c

   1 /* GIO - GLib Input, Output and Streaming Library
   2  *
   3  * Copyright (C) 2011 Collabora, Ltd.
   4  *
   5  * This library is free software; you can redistribute it and/or
   6  * modify it under the terms of the GNU Lesser General Public
   7  * License as published by the Free Software Foundation; either
   8  * version 2 of the License, or (at your option) any later version.
   9  *
  10  * This library 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 GNU
  13  * Lesser General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU Lesser General
  16  * Public License along with this library; if not, write to the
  17  * Free Software Foundation, Inc., 59 Temple Place, Suite 330,
  18  * Boston, MA 02111-1307, USA.
  19  *
  20  * Author: Stef Walter <stefw@collabora.co.uk>
  21  */
  22
  23 #include "config.h"
  24
  25 #include <string.h>
  26
  27 #include "gtlsinteraction.h"
  28 #include "gtlspassword.h"
  29 #include "gasyncresult.h"
  30 #include "gcancellable.h"
  31 #include "gtask.h"
  32 #include "gioenumtypes.h"
  33 #include "glibintl.h"
  34
  35
  36 /**
  37  * SECTION:gtlsinteraction
  38  * @short_description: Interaction with the user during TLS operations.
  39  * @include: gio/gio.h
  40  *
  41  * #GTlsInteraction provides a mechanism for the TLS connection and database
  42  * code to interact with the user. It can be used to ask the user for passwords.
  43  *
  44  * To use a #GTlsInteraction with a TLS connection use
  45  * g_tls_connection_set_interaction().
  46  *
  47  * Callers should instantiate a derived class that implements the various
  48  * interaction methods to show the required dialogs.
  49  *
  50  * Callers should use the 'invoke' functions like
  51  * g_tls_interaction_invoke_ask_password() to run interaction methods. These
  52  * functions make sure that the interaction is invoked in the main loop
  53  * and not in the current thread, if the current thread is not running the
  54  * main loop.
  55  *
  56  * Derived classes can choose to implement whichever interactions methods they'd
  57  * like to support by overriding those virtual methods in their class
  58  * initialization function. Any interactions not implemented will return
  59  * %G_TLS_INTERACTION_UNHANDLED. If a derived class implements an async method,
  60  * it must also implement the corresponding finish method.
  61  */
  62
  63 /**
  64  * GTlsInteraction:
  65  *
  66  * An object representing interaction that the TLS connection and database
  67  * might have with the user.
  68  *
  69  * Since: 2.30
  70  */
  71
  72 /**
  73  * GTlsInteractionClass:
  74  * @ask_password: ask for a password synchronously. If the implementation
  75  *     returns %G_TLS_INTERACTION_HANDLED, then the password argument should
  76  *     have been filled in by using g_tls_password_set_value() or a similar
  77  *     function.
  78  * @ask_password_async: ask for a password asynchronously.
  79  * @ask_password_finish: complete operation to ask for a password asynchronously.
  80  *     If the implementation returns %G_TLS_INTERACTION_HANDLED, then the
  81  *     password argument of the async method should have been filled in by using
  82  *     g_tls_password_set_value() or a similar function.
  83  *
  84  * The class for #GTlsInteraction. Derived classes implement the various
  85  * virtual interaction methods to handle TLS interactions.
  86  *
  87  * Derived classes can choose to implement whichever interactions methods they'd
  88  * like to support by overriding those virtual methods in their class
  89  * initialization function. If a derived class implements an async method,
  90  * it must also implement the corresponding finish method.
  91  *
  92  * The synchronous interaction methods should implement to display modal dialogs,
  93  * and the asynchronous methods to display modeless dialogs.
  94  *
  95  * If the user cancels an interaction, then the result should be
  96  * %G_TLS_INTERACTION_FAILED and the error should be set with a domain of
  97  * %G_IO_ERROR and code of %G_IO_ERROR_CANCELLED.
  98  *
  99  * Since: 2.30
 100  */
 101
 102 struct _GTlsInteractionPrivate {
 103   GMainContext *context;
 104 };
 105
 106 G_DEFINE_TYPE_WITH_PRIVATE (GTlsInteraction, g_tls_interaction, G_TYPE_OBJECT)
 107
 108 typedef struct {
 109   GMutex mutex;
 110
 111   /* Input arguments */
 112   GTlsInteraction *interaction;
 113   GObject *argument;
 114   GCancellable *cancellable;
 115
 116   /* Used when we're invoking async interactions */
 117   GAsyncReadyCallback callback;
 118   gpointer user_data;
 119
 120   /* Used when we expect results */
 121   GTlsInteractionResult result;
 122   GError *error;
 123   gboolean complete;
 124   GCond cond;
 125 } InvokeClosure;
 126
 127 static void
 128 invoke_closure_free (gpointer data)
 129 {
 130   InvokeClosure *closure = data;
 131   g_assert (closure);
 132   g_object_unref (closure->interaction);
 133   g_clear_object (&closure->argument);
 134   g_clear_object (&closure->cancellable);
 135   g_cond_clear (&closure->cond);
 136   g_mutex_clear (&closure->mutex);
 137   g_clear_error (&closure->error);
 138
 139   /* Insurance that we've actually used these before freeing */
 140   g_assert (closure->callback == NULL);
 141   g_assert (closure->user_data == NULL);
 142
 143   g_free (closure);
 144 }
 145
 146 static InvokeClosure *
 147 invoke_closure_new (GTlsInteraction *interaction,
 148                     GObject         *argument,
 149                     GCancellable    *cancellable)
 150 {
 151   InvokeClosure *closure = g_new0 (InvokeClosure, 1);
 152   closure->interaction = g_object_ref (interaction);
 153   closure->argument = argument ? g_object_ref (argument) : NULL;
 154   closure->cancellable = cancellable ? g_object_ref (cancellable) : NULL;
 155   g_mutex_init (&closure->mutex);
 156   g_cond_init (&closure->cond);
 157   closure->result = G_TLS_INTERACTION_UNHANDLED;
 158   return closure;
 159 }
 160
 161 static GTlsInteractionResult
 162 invoke_closure_wait_and_free (InvokeClosure *closure,
 163                               GError       **error)
 164 {
 165   GTlsInteractionResult result;
 166
 167   g_mutex_lock (&closure->mutex);
 168
 169   while (!closure->complete)
 170     g_cond_wait (&closure->cond, &closure->mutex);
 171
 172   g_mutex_unlock (&closure->mutex);
 173
 174   if (closure->error)
 175     {
 176       g_propagate_error (error, closure->error);
 177       closure->error = NULL;
 178     }
 179   result = closure->result;
 180
 181   invoke_closure_free (closure);
 182   return result;
 183 }
 184
 185 static void
 186 g_tls_interaction_init (GTlsInteraction *interaction)
 187 {
 188   interaction->priv = g_tls_interaction_get_instance_private (interaction);
 189   interaction->priv->context = g_main_context_ref_thread_default ();
 190 }
 191
 192 static void
 193 g_tls_interaction_finalize (GObject *object)
 194 {
 195   GTlsInteraction *interaction = G_TLS_INTERACTION (object);
 196
 197   g_main_context_unref (interaction->priv->context);
 198
 199   G_OBJECT_CLASS (g_tls_interaction_parent_class)->finalize (object);
 200 }
 201
 202 static void
 203 g_tls_interaction_class_init (GTlsInteractionClass *klass)
 204 {
 205   GObjectClass *gobject_class = G_OBJECT_CLASS (klass);
 206
 207   gobject_class->finalize = g_tls_interaction_finalize;
 208 }
 209
 210 static gboolean
 211 on_invoke_ask_password_sync (gpointer user_data)
 212 {
 213   InvokeClosure *closure = user_data;
 214   GTlsInteractionClass *klass;
 215
 216   g_mutex_lock (&closure->mutex);
 217
 218   klass = G_TLS_INTERACTION_GET_CLASS (closure->interaction);
 219   g_assert (klass->ask_password);
 220
 221   closure->result = klass->ask_password (closure->interaction,
 222                                          G_TLS_PASSWORD (closure->argument),
 223                                          closure->cancellable,
 224                                          &closure->error);
 225
 226   closure->complete = TRUE;
 227   g_cond_signal (&closure->cond);
 228   g_mutex_unlock (&closure->mutex);
 229
 230   return FALSE; /* don't call again */
 231 }
 232
 233 static void
 234 on_async_as_sync_complete (GObject      *source,
 235                            GAsyncResult *result,
 236                            gpointer      user_data)
 237 {
 238   InvokeClosure *closure = user_data;
 239   GTlsInteractionClass *klass;
 240
 241   g_mutex_lock (&closure->mutex);
 242
 243   klass = G_TLS_INTERACTION_GET_CLASS (closure->interaction);
 244   g_assert (klass->ask_password_finish);
 245
 246   closure->result = klass->ask_password_finish (closure->interaction,
 247                                                 result,
 248                                                 &closure->error);
 249
 250   closure->complete = TRUE;
 251   g_cond_signal (&closure->cond);
 252   g_mutex_unlock (&closure->mutex);
 253 }
 254
 255 static gboolean
 256 on_invoke_ask_password_async_as_sync (gpointer user_data)
 257 {
 258   InvokeClosure *closure = user_data;
 259   GTlsInteractionClass *klass;
 260
 261   g_mutex_lock (&closure->mutex);
 262
 263   klass = G_TLS_INTERACTION_GET_CLASS (closure->interaction);
 264   g_assert (klass->ask_password_async);
 265
 266   klass->ask_password_async (closure->interaction,
 267                              G_TLS_PASSWORD (closure->argument),
 268                              closure->cancellable,
 269                              on_async_as_sync_complete,
 270                              closure);
 271
 272   /* Note that we've used these */
 273   closure->callback = NULL;
 274   closure->user_data = NULL;
 275
 276   g_mutex_unlock (&closure->mutex);
 277
 278   return FALSE; /* don't call again */
 279 }
 280
 281 /**
 282  * g_tls_interaction_invoke_ask_password:
 283  * @interaction: a #GTlsInteraction object
 284  * @password: a #GTlsPassword object
 285  * @cancellable: an optional #GCancellable cancellation object
 286  * @error: an optional location to place an error on failure
 287  *
 288  * Invoke the interaction to ask the user for a password. It invokes this
 289  * interaction in the main loop, specifically the #GMainContext returned by
 290  * g_main_context_get_thread_default() when the interaction is created. This
 291  * is called by called by #GTlsConnection or #GTlsDatabase to ask the user
 292  * for a password.
 293  *
 294  * Derived subclasses usually implement a password prompt, although they may
 295  * also choose to provide a password from elsewhere. The @password value will
 296  * be filled in and then @callback will be called. Alternatively the user may
 297  * abort this password request, which will usually abort the TLS connection.
 298  *
 299  * The implementation can either be a synchronous (eg: modal dialog) or an
 300  * asynchronous one (eg: modeless dialog). This function will take care of
 301  * calling which ever one correctly.
 302  *
 303  * If the interaction is cancelled by the cancellation object, or by the
 304  * user then %G_TLS_INTERACTION_FAILED will be returned with an error that
 305  * contains a %G_IO_ERROR_CANCELLED error code. Certain implementations may
 306  * not support immediate cancellation.
 307  *
 308  * Returns: The status of the ask password interaction.
 309  *
 310  * Since: 2.30
 311  */
 312 GTlsInteractionResult
 313 g_tls_interaction_invoke_ask_password (GTlsInteraction    *interaction,
 314                                        GTlsPassword       *password,
 315                                        GCancellable       *cancellable,
 316                                        GError            **error)
 317 {
 318   GTlsInteractionResult result;
 319   InvokeClosure *closure;
 320   GTlsInteractionClass *klass;
 321   gboolean complete;
 322
 323   g_return_val_if_fail (G_IS_TLS_INTERACTION (interaction), G_TLS_INTERACTION_UNHANDLED);
 324   g_return_val_if_fail (G_IS_TLS_PASSWORD (password), G_TLS_INTERACTION_UNHANDLED);
 325   g_return_val_if_fail (cancellable == NULL || G_IS_CANCELLABLE (cancellable), G_TLS_INTERACTION_UNHANDLED);
 326
 327   closure = invoke_closure_new (interaction, G_OBJECT (password), cancellable);
 328
 329   klass = G_TLS_INTERACTION_GET_CLASS (interaction);
 330   if (klass->ask_password)
 331     {
 332       g_main_context_invoke (interaction->priv->context,
 333                              on_invoke_ask_password_sync, closure);
 334       result = invoke_closure_wait_and_free (closure, error);
 335     }
 336   else if (klass->ask_password_async)
 337     {
 338       g_return_val_if_fail (klass->ask_password_finish, G_TLS_INTERACTION_UNHANDLED);
 339       g_main_context_invoke (interaction->priv->context,
 340                              on_invoke_ask_password_async_as_sync, closure);
 341
 342       /*
 343        * Handle the case where we've been called from within the main context
 344        * or in the case where the main context is not running. This approximates
 345        * the behavior of a modal dialog.
 346        */
 347       if (g_main_context_acquire (interaction->priv->context))
 348         {
 349           for (;;)
 350             {
 351               g_mutex_lock (&closure->mutex);
 352               complete = closure->complete;
 353               g_mutex_unlock (&closure->mutex);
 354               if (complete)
 355                 break;
 356               g_main_context_iteration (interaction->priv->context, TRUE);
 357             }
 358
 359           g_main_context_release (interaction->priv->context);
 360
 361           if (closure->error)
 362             {
 363               g_propagate_error (error, closure->error);
 364               closure->error = NULL;
 365             }
 366
 367           result = closure->result;
 368           invoke_closure_free (closure);
 369         }
 370
 371       /*
 372        * Handle the case where we're in a different thread than the main
 373        * context and a main loop is running.
 374        */
 375       else
 376         {
 377           result = invoke_closure_wait_and_free (closure, error);
 378         }
 379     }
 380   else
 381     {
 382       result = G_TLS_INTERACTION_UNHANDLED;
 383       invoke_closure_free (closure);
 384     }
 385
 386   return result;
 387 }
 388
 389
 390 /**
 391  * g_tls_interaction_ask_password:
 392  * @interaction: a #GTlsInteraction object
 393  * @password: a #GTlsPassword object
 394  * @cancellable: an optional #GCancellable cancellation object
 395  * @error: an optional location to place an error on failure
 396  *
 397  * Run synchronous interaction to ask the user for a password. In general,
 398  * g_tls_interaction_invoke_ask_password() should be used instead of this
 399  * function.
 400  *
 401  * Derived subclasses usually implement a password prompt, although they may
 402  * also choose to provide a password from elsewhere. The @password value will
 403  * be filled in and then @callback will be called. Alternatively the user may
 404  * abort this password request, which will usually abort the TLS connection.
 405  *
 406  * If the interaction is cancelled by the cancellation object, or by the
 407  * user then %G_TLS_INTERACTION_FAILED will be returned with an error that
 408  * contains a %G_IO_ERROR_CANCELLED error code. Certain implementations may
 409  * not support immediate cancellation.
 410  *
 411  * Returns: The status of the ask password interaction.
 412  *
 413  * Since: 2.30
 414  */
 415 GTlsInteractionResult
 416 g_tls_interaction_ask_password (GTlsInteraction    *interaction,
 417                                 GTlsPassword       *password,
 418                                 GCancellable       *cancellable,
 419                                 GError            **error)
 420 {
 421   GTlsInteractionClass *klass;
 422
 423   g_return_val_if_fail (G_IS_TLS_INTERACTION (interaction), G_TLS_INTERACTION_UNHANDLED);
 424   g_return_val_if_fail (G_IS_TLS_PASSWORD (password), G_TLS_INTERACTION_UNHANDLED);
 425   g_return_val_if_fail (cancellable == NULL || G_IS_CANCELLABLE (cancellable), G_TLS_INTERACTION_UNHANDLED);
 426
 427   klass = G_TLS_INTERACTION_GET_CLASS (interaction);
 428   if (klass->ask_password)
 429     return (klass->ask_password) (interaction, password, cancellable, error);
 430   else
 431     return G_TLS_INTERACTION_UNHANDLED;
 432 }
 433
 434 /**
 435  * g_tls_interaction_ask_password_async:
 436  * @interaction: a #GTlsInteraction object
 437  * @password: a #GTlsPassword object
 438  * @cancellable: an optional #GCancellable cancellation object
 439  * @callback: (allow-none): will be called when the interaction completes
 440  * @user_data: (allow-none): data to pass to the @callback
 441  *
 442  * Run asynchronous interaction to ask the user for a password. In general,
 443  * g_tls_interaction_invoke_ask_password() should be used instead of this
 444  * function.
 445  *
 446  * Derived subclasses usually implement a password prompt, although they may
 447  * also choose to provide a password from elsewhere. The @password value will
 448  * be filled in and then @callback will be called. Alternatively the user may
 449  * abort this password request, which will usually abort the TLS connection.
 450  *
 451  * If the interaction is cancelled by the cancellation object, or by the
 452  * user then %G_TLS_INTERACTION_FAILED will be returned with an error that
 453  * contains a %G_IO_ERROR_CANCELLED error code. Certain implementations may
 454  * not support immediate cancellation.
 455  *
 456  * Certain implementations may not support immediate cancellation.
 457  *
 458  * Since: 2.30
 459  */
 460 void
 461 g_tls_interaction_ask_password_async (GTlsInteraction    *interaction,
 462                                       GTlsPassword       *password,
 463                                       GCancellable       *cancellable,
 464                                       GAsyncReadyCallback callback,
 465                                       gpointer            user_data)
 466 {
 467   GTlsInteractionClass *klass;
 468   GTask *task;
 469
 470   g_return_if_fail (G_IS_TLS_INTERACTION (interaction));
 471   g_return_if_fail (G_IS_TLS_PASSWORD (password));
 472   g_return_if_fail (cancellable == NULL || G_IS_CANCELLABLE (cancellable));
 473
 474   klass = G_TLS_INTERACTION_GET_CLASS (interaction);
 475   if (klass->ask_password_async)
 476     {
 477       g_return_if_fail (klass->ask_password_finish);
 478       (klass->ask_password_async) (interaction, password, cancellable,
 479                                    callback, user_data);
 480     }
 481   else
 482     {
 483       task = g_task_new (interaction, cancellable, callback, user_data);
 484       g_task_set_source_tag (task, g_tls_interaction_ask_password_async);
 485       g_task_return_int (task, G_TLS_INTERACTION_UNHANDLED);
 486       g_object_unref (task);
 487     }
 488 }
 489
 490 /**
 491  * g_tls_interaction_ask_password_finish:
 492  * @interaction: a #GTlsInteraction object
 493  * @result: the result passed to the callback
 494  * @error: an optional location to place an error on failure
 495  *
 496  * Complete an ask password user interaction request. This should be once
 497  * the g_tls_interaction_ask_password_async() completion callback is called.
 498  *
 499  * If %G_TLS_INTERACTION_HANDLED is returned, then the #GTlsPassword passed
 500  * to g_tls_interaction_ask_password() will have its password filled in.
 501  *
 502  * If the interaction is cancelled by the cancellation object, or by the
 503  * user then %G_TLS_INTERACTION_FAILED will be returned with an error that
 504  * contains a %G_IO_ERROR_CANCELLED error code.
 505  *
 506  * Returns: The status of the ask password interaction.
 507  *
 508  * Since: 2.30
 509  */
 510 GTlsInteractionResult
 511 g_tls_interaction_ask_password_finish (GTlsInteraction    *interaction,
 512                                        GAsyncResult       *result,
 513                                        GError            **error)
 514 {
 515   GTlsInteractionClass *klass;
 516
 517   g_return_val_if_fail (G_IS_TLS_INTERACTION (interaction), G_TLS_INTERACTION_UNHANDLED);
 518   g_return_val_if_fail (G_IS_ASYNC_RESULT (result), G_TLS_INTERACTION_UNHANDLED);
 519
 520   klass = G_TLS_INTERACTION_GET_CLASS (interaction);
 521   if (klass->ask_password_finish)
 522     {
 523       g_return_val_if_fail (klass->ask_password_async != NULL, G_TLS_INTERACTION_UNHANDLED);
 524
 525       return (klass->ask_password_finish) (interaction, result, error);
 526     }
 527   else
 528     {
 529       g_return_val_if_fail (g_async_result_is_tagged (result, g_tls_interaction_ask_password_async), G_TLS_INTERACTION_UNHANDLED);
 530
 531       return g_task_propagate_int (G_TASK (result), error);
 532     }
 533 }