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