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 (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_TYPE_INSTANCE_GET_PRIVATE (interaction, G_TYPE_TLS_INTERACTION,
 189                                                    GTlsInteractionPrivate);
 190   interaction->priv->context = g_main_context_ref_thread_default ();
 191 }
 192
 193 static void
 194 g_tls_interaction_finalize (GObject *object)
 195 {
 196   GTlsInteraction *interaction = G_TLS_INTERACTION (object);
 197
 198   g_main_context_unref (interaction->priv->context);
 199
 200   G_OBJECT_CLASS (g_tls_interaction_parent_class)->finalize (object);
 201 }
 202
 203 static void
 204 g_tls_interaction_class_init (GTlsInteractionClass *klass)
 205 {
 206   GObjectClass *gobject_class = G_OBJECT_CLASS (klass);
 207
 208   gobject_class->finalize = g_tls_interaction_finalize;
 209
 210   g_type_class_add_private (klass, sizeof (GTlsInteractionPrivate));
 211 }
 212
 213 static gboolean
 214 on_invoke_ask_password_sync (gpointer user_data)
 215 {
 216   InvokeClosure *closure = user_data;
 217   GTlsInteractionClass *klass;
 218
 219   g_mutex_lock (&closure->mutex);
 220
 221   klass = G_TLS_INTERACTION_GET_CLASS (closure->interaction);
 222   g_assert (klass->ask_password);
 223
 224   closure->result = klass->ask_password (closure->interaction,
 225                                          G_TLS_PASSWORD (closure->argument),
 226                                          closure->cancellable,
 227                                          &closure->error);
 228
 229   closure->complete = TRUE;
 230   g_cond_signal (&closure->cond);
 231   g_mutex_unlock (&closure->mutex);
 232
 233   return FALSE; /* don't call again */
 234 }
 235
 236 static void
 237 on_async_as_sync_complete (GObject      *source,
 238                            GAsyncResult *result,
 239                            gpointer      user_data)
 240 {
 241   InvokeClosure *closure = user_data;
 242   GTlsInteractionClass *klass;
 243
 244   g_mutex_lock (&closure->mutex);
 245
 246   klass = G_TLS_INTERACTION_GET_CLASS (closure->interaction);
 247   g_assert (klass->ask_password_finish);
 248
 249   closure->result = klass->ask_password_finish (closure->interaction,
 250                                                 result,
 251                                                 &closure->error);
 252
 253   closure->complete = TRUE;
 254   g_cond_signal (&closure->cond);
 255   g_mutex_unlock (&closure->mutex);
 256 }
 257
 258 static gboolean
 259 on_invoke_ask_password_async_as_sync (gpointer user_data)
 260 {
 261   InvokeClosure *closure = user_data;
 262   GTlsInteractionClass *klass;
 263
 264   g_mutex_lock (&closure->mutex);
 265
 266   klass = G_TLS_INTERACTION_GET_CLASS (closure->interaction);
 267   g_assert (klass->ask_password_async);
 268
 269   klass->ask_password_async (closure->interaction,
 270                              G_TLS_PASSWORD (closure->argument),
 271                              closure->cancellable,
 272                              on_async_as_sync_complete,
 273                              closure);
 274
 275   /* Note that we've used these */
 276   closure->callback = NULL;
 277   closure->user_data = NULL;
 278
 279   g_mutex_unlock (&closure->mutex);
 280
 281   return FALSE; /* don't call again */
 282 }
 283
 284 /**
 285  * g_tls_interaction_invoke_ask_password:
 286  * @interaction: a #GTlsInteraction object
 287  * @password: a #GTlsPassword object
 288  * @cancellable: an optional #GCancellable cancellation object
 289  * @error: an optional location to place an error on failure
 290  *
 291  * Invoke the interaction to ask the user for a password. It invokes this
 292  * interaction in the main loop, specifically the #GMainContext returned by
 293  * g_main_context_get_thread_default() when the interaction is created. This
 294  * is called by called by #GTlsConnection or #GTlsDatabase to ask the user
 295  * for a password.
 296  *
 297  * Derived subclasses usually implement a password prompt, although they may
 298  * also choose to provide a password from elsewhere. The @password value will
 299  * be filled in and then @callback will be called. Alternatively the user may
 300  * abort this password request, which will usually abort the TLS connection.
 301  *
 302  * The implementation can either be a synchronous (eg: modal dialog) or an
 303  * asynchronous one (eg: modeless dialog). This function will take care of
 304  * calling which ever one correctly.
 305  *
 306  * If the interaction is cancelled by the cancellation object, or by the
 307  * user then %G_TLS_INTERACTION_FAILED will be returned with an error that
 308  * contains a %G_IO_ERROR_CANCELLED error code. Certain implementations may
 309  * not support immediate cancellation.
 310  *
 311  * Returns: The status of the ask password interaction.
 312  *
 313  * Since: 2.30
 314  */
 315 GTlsInteractionResult
 316 g_tls_interaction_invoke_ask_password (GTlsInteraction    *interaction,
 317                                        GTlsPassword       *password,
 318                                        GCancellable       *cancellable,
 319                                        GError            **error)
 320 {
 321   GTlsInteractionResult result;
 322   InvokeClosure *closure;
 323   GTlsInteractionClass *klass;
 324   gboolean complete;
 325
 326   g_return_val_if_fail (G_IS_TLS_INTERACTION (interaction), G_TLS_INTERACTION_UNHANDLED);
 327   g_return_val_if_fail (G_IS_TLS_PASSWORD (password), G_TLS_INTERACTION_UNHANDLED);
 328   g_return_val_if_fail (cancellable == NULL || G_IS_CANCELLABLE (cancellable), G_TLS_INTERACTION_UNHANDLED);
 329
 330   closure = invoke_closure_new (interaction, G_OBJECT (password), cancellable);
 331
 332   klass = G_TLS_INTERACTION_GET_CLASS (interaction);
 333   if (klass->ask_password)
 334     {
 335       g_main_context_invoke (interaction->priv->context,
 336                              on_invoke_ask_password_sync, closure);
 337       result = invoke_closure_wait_and_free (closure, error);
 338     }
 339   else if (klass->ask_password_async)
 340     {
 341       g_return_val_if_fail (klass->ask_password_finish, G_TLS_INTERACTION_UNHANDLED);
 342       g_main_context_invoke (interaction->priv->context,
 343                              on_invoke_ask_password_async_as_sync, closure);
 344
 345       /*
 346        * Handle the case where we've been called from within the main context
 347        * or in the case where the main context is not running. This approximates
 348        * the behavior of a modal dialog.
 349        */
 350       if (g_main_context_acquire (interaction->priv->context))
 351         {
 352           for (;;)
 353             {
 354               g_mutex_lock (&closure->mutex);
 355               complete = closure->complete;
 356               g_mutex_unlock (&closure->mutex);
 357               if (complete)
 358                 break;
 359               g_main_context_iteration (interaction->priv->context, TRUE);
 360             }
 361
 362           g_main_context_release (interaction->priv->context);
 363
 364           if (closure->error)
 365             {
 366               g_propagate_error (error, closure->error);
 367               closure->error = NULL;
 368             }
 369
 370           result = closure->result;
 371           invoke_closure_free (closure);
 372         }
 373
 374       /*
 375        * Handle the case where we're in a different thread than the main
 376        * context and a main loop is running.
 377        */
 378       else
 379         {
 380           result = invoke_closure_wait_and_free (closure, error);
 381         }
 382     }
 383   else
 384     {
 385       result = G_TLS_INTERACTION_UNHANDLED;
 386       invoke_closure_free (closure);
 387     }
 388
 389   return result;
 390 }
 391
 392
 393 /**
 394  * g_tls_interaction_ask_password:
 395  * @interaction: a #GTlsInteraction object
 396  * @password: a #GTlsPassword object
 397  * @cancellable: an optional #GCancellable cancellation object
 398  * @error: an optional location to place an error on failure
 399  *
 400  * Run synchronous interaction to ask the user for a password. In general,
 401  * g_tls_interaction_invoke_ask_password() should be used instead of this
 402  * function.
 403  *
 404  * Derived subclasses usually implement a password prompt, although they may
 405  * also choose to provide a password from elsewhere. The @password value will
 406  * be filled in and then @callback will be called. Alternatively the user may
 407  * abort this password request, which will usually abort the TLS connection.
 408  *
 409  * If the interaction is cancelled by the cancellation object, or by the
 410  * user then %G_TLS_INTERACTION_FAILED will be returned with an error that
 411  * contains a %G_IO_ERROR_CANCELLED error code. Certain implementations may
 412  * not support immediate cancellation.
 413  *
 414  * Returns: The status of the ask password interaction.
 415  *
 416  * Since: 2.30
 417  */
 418 GTlsInteractionResult
 419 g_tls_interaction_ask_password (GTlsInteraction    *interaction,
 420                                 GTlsPassword       *password,
 421                                 GCancellable       *cancellable,
 422                                 GError            **error)
 423 {
 424   GTlsInteractionClass *klass;
 425
 426   g_return_val_if_fail (G_IS_TLS_INTERACTION (interaction), G_TLS_INTERACTION_UNHANDLED);
 427   g_return_val_if_fail (G_IS_TLS_PASSWORD (password), G_TLS_INTERACTION_UNHANDLED);
 428   g_return_val_if_fail (cancellable == NULL || G_IS_CANCELLABLE (cancellable), G_TLS_INTERACTION_UNHANDLED);
 429
 430   klass = G_TLS_INTERACTION_GET_CLASS (interaction);
 431   if (klass->ask_password)
 432     return (klass->ask_password) (interaction, password, cancellable, error);
 433   else
 434     return G_TLS_INTERACTION_UNHANDLED;
 435 }
 436
 437 /**
 438  * g_tls_interaction_ask_password_async:
 439  * @interaction: a #GTlsInteraction object
 440  * @password: a #GTlsPassword object
 441  * @cancellable: an optional #GCancellable cancellation object
 442  * @callback: (allow-none): will be called when the interaction completes
 443  * @user_data: (allow-none): data to pass to the @callback
 444  *
 445  * Run asynchronous interaction to ask the user for a password. In general,
 446  * g_tls_interaction_invoke_ask_password() should be used instead of this
 447  * function.
 448  *
 449  * Derived subclasses usually implement a password prompt, although they may
 450  * also choose to provide a password from elsewhere. The @password value will
 451  * be filled in and then @callback will be called. Alternatively the user may
 452  * abort this password request, which will usually abort the TLS connection.
 453  *
 454  * If the interaction is cancelled by the cancellation object, or by the
 455  * user then %G_TLS_INTERACTION_FAILED will be returned with an error that
 456  * contains a %G_IO_ERROR_CANCELLED error code. Certain implementations may
 457  * not support immediate cancellation.
 458  *
 459  * Certain implementations may not support immediate cancellation.
 460  *
 461  * Since: 2.30
 462  */
 463 void
 464 g_tls_interaction_ask_password_async (GTlsInteraction    *interaction,
 465                                       GTlsPassword       *password,
 466                                       GCancellable       *cancellable,
 467                                       GAsyncReadyCallback callback,
 468                                       gpointer            user_data)
 469 {
 470   GTlsInteractionClass *klass;
 471   GTask *task;
 472
 473   g_return_if_fail (G_IS_TLS_INTERACTION (interaction));
 474   g_return_if_fail (G_IS_TLS_PASSWORD (password));
 475   g_return_if_fail (cancellable == NULL || G_IS_CANCELLABLE (cancellable));
 476
 477   klass = G_TLS_INTERACTION_GET_CLASS (interaction);
 478   if (klass->ask_password_async)
 479     {
 480       g_return_if_fail (klass->ask_password_finish);
 481       (klass->ask_password_async) (interaction, password, cancellable,
 482                                    callback, user_data);
 483     }
 484   else
 485     {
 486       task = g_task_new (interaction, cancellable, callback, user_data);
 487       g_task_set_source_tag (task, g_tls_interaction_ask_password_async);
 488       g_task_return_int (task, G_TLS_INTERACTION_UNHANDLED);
 489       g_object_unref (task);
 490     }
 491 }
 492
 493 /**
 494  * g_tls_interaction_ask_password_finish:
 495  * @interaction: a #GTlsInteraction object
 496  * @result: the result passed to the callback
 497  * @error: an optional location to place an error on failure
 498  *
 499  * Complete an ask password user interaction request. This should be once
 500  * the g_tls_interaction_ask_password_async() completion callback is called.
 501  *
 502  * If %G_TLS_INTERACTION_HANDLED is returned, then the #GTlsPassword passed
 503  * to g_tls_interaction_ask_password() will have its password filled in.
 504  *
 505  * If the interaction is cancelled by the cancellation object, or by the
 506  * user then %G_TLS_INTERACTION_FAILED will be returned with an error that
 507  * contains a %G_IO_ERROR_CANCELLED error code.
 508  *
 509  * Returns: The status of the ask password interaction.
 510  *
 511  * Since: 2.30
 512  */
 513 GTlsInteractionResult
 514 g_tls_interaction_ask_password_finish (GTlsInteraction    *interaction,
 515                                        GAsyncResult       *result,
 516                                        GError            **error)
 517 {
 518   GTlsInteractionClass *klass;
 519
 520   g_return_val_if_fail (G_IS_TLS_INTERACTION (interaction), G_TLS_INTERACTION_UNHANDLED);
 521   g_return_val_if_fail (G_IS_ASYNC_RESULT (result), G_TLS_INTERACTION_UNHANDLED);
 522
 523   klass = G_TLS_INTERACTION_GET_CLASS (interaction);
 524   if (klass->ask_password_finish)
 525     {
 526       g_return_val_if_fail (klass->ask_password_async != NULL, G_TLS_INTERACTION_UNHANDLED);
 527
 528       return (klass->ask_password_finish) (interaction, result, error);
 529     }
 530   else
 531     {
 532       g_return_val_if_fail (g_async_result_is_tagged (result, g_tls_interaction_ask_password_async), G_TLS_INTERACTION_UNHANDLED);
 533
 534       return g_task_propagate_int (G_TASK (result), error);
 535     }
 536 }