gio/gdbusauth.c

   1 /* GDBus - GLib D-Bus Library
   2  *
   3  * Copyright (C) 2008-2010 Red Hat, Inc.
   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, see <http://www.gnu.org/licenses/>.
  17  *
  18  * Author: David Zeuthen <davidz@redhat.com>
  19  */
  20
  21 #include "config.h"
  22
  23 #include "gdbusauth.h"
  24
  25 #include "gdbusauthmechanismanon.h"
  26 #include "gdbusauthmechanismexternal.h"
  27 #include "gdbusauthmechanismsha1.h"
  28 #include "gdbusauthobserver.h"
  29
  30 #include "gdbuserror.h"
  31 #include "gdbusutils.h"
  32 #include "gioenumtypes.h"
  33 #include "gcredentials.h"
  34 #include "gdbusprivate.h"
  35 #include "giostream.h"
  36 #include "gdatainputstream.h"
  37 #include "gdataoutputstream.h"
  38
  39 #ifdef G_OS_UNIX
  40 #include "gnetworking.h"
  41 #include "gunixconnection.h"
  42 #include "gunixcredentialsmessage.h"
  43 #endif
  44
  45 #include "glibintl.h"
  46
  47 G_GNUC_PRINTF(1, 2)
  48 static void
  49 debug_print (const gchar *message, ...)
  50 {
  51   if (G_UNLIKELY (_g_dbus_debug_authentication ()))
  52     {
  53       gchar *s;
  54       GString *str;
  55       va_list var_args;
  56       guint n;
  57
  58       _g_dbus_debug_print_lock ();
  59
  60       va_start (var_args, message);
  61       s = g_strdup_vprintf (message, var_args);
  62       va_end (var_args);
  63
  64       str = g_string_new (NULL);
  65       for (n = 0; s[n] != '\0'; n++)
  66         {
  67           if (G_UNLIKELY (s[n] == '\r'))
  68             g_string_append (str, "\\r");
  69           else if (G_UNLIKELY (s[n] == '\n'))
  70             g_string_append (str, "\\n");
  71           else
  72             g_string_append_c (str, s[n]);
  73         }
  74       g_print ("GDBus-debug:Auth: %s\n", str->str);
  75       g_string_free (str, TRUE);
  76       g_free (s);
  77
  78       _g_dbus_debug_print_unlock ();
  79     }
  80 }
  81
  82 typedef struct
  83 {
  84   const gchar *name;
  85   gint priority;
  86   GType gtype;
  87 } Mechanism;
  88
  89 static void mechanism_free (Mechanism *m);
  90
  91 struct _GDBusAuthPrivate
  92 {
  93   GIOStream *stream;
  94
  95   /* A list of available Mechanism, sorted according to priority  */
  96   GList *available_mechanisms;
  97 };
  98
  99 enum
 100 {
 101   PROP_0,
 102   PROP_STREAM
 103 };
 104
 105 G_DEFINE_TYPE_WITH_PRIVATE (GDBusAuth, _g_dbus_auth, G_TYPE_OBJECT)
 106
 107 /* ---------------------------------------------------------------------------------------------------- */
 108
 109 static void
 110 _g_dbus_auth_finalize (GObject *object)
 111 {
 112   GDBusAuth *auth = G_DBUS_AUTH (object);
 113
 114   if (auth->priv->stream != NULL)
 115     g_object_unref (auth->priv->stream);
 116   g_list_free_full (auth->priv->available_mechanisms, (GDestroyNotify) mechanism_free);
 117
 118   if (G_OBJECT_CLASS (_g_dbus_auth_parent_class)->finalize != NULL)
 119     G_OBJECT_CLASS (_g_dbus_auth_parent_class)->finalize (object);
 120 }
 121
 122 static void
 123 _g_dbus_auth_get_property (GObject    *object,
 124                            guint       prop_id,
 125                            GValue     *value,
 126                            GParamSpec *pspec)
 127 {
 128   GDBusAuth *auth = G_DBUS_AUTH (object);
 129
 130   switch (prop_id)
 131     {
 132     case PROP_STREAM:
 133       g_value_set_object (value, auth->priv->stream);
 134       break;
 135
 136     default:
 137       G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
 138       break;
 139     }
 140 }
 141
 142 static void
 143 _g_dbus_auth_set_property (GObject      *object,
 144                            guint         prop_id,
 145                            const GValue *value,
 146                            GParamSpec   *pspec)
 147 {
 148   GDBusAuth *auth = G_DBUS_AUTH (object);
 149
 150   switch (prop_id)
 151     {
 152     case PROP_STREAM:
 153       auth->priv->stream = g_value_dup_object (value);
 154       break;
 155
 156     default:
 157       G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
 158       break;
 159     }
 160 }
 161
 162 static void
 163 _g_dbus_auth_class_init (GDBusAuthClass *klass)
 164 {
 165   GObjectClass *gobject_class;
 166
 167   gobject_class = G_OBJECT_CLASS (klass);
 168   gobject_class->get_property = _g_dbus_auth_get_property;
 169   gobject_class->set_property = _g_dbus_auth_set_property;
 170   gobject_class->finalize     = _g_dbus_auth_finalize;
 171
 172   g_object_class_install_property (gobject_class,
 173                                    PROP_STREAM,
 174                                    g_param_spec_object ("stream",
 175                                                         P_("IO Stream"),
 176                                                         P_("The underlying GIOStream used for I/O"),
 177                                                         G_TYPE_IO_STREAM,
 178                                                         G_PARAM_READABLE |
 179                                                         G_PARAM_WRITABLE |
 180                                                         G_PARAM_CONSTRUCT_ONLY |
 181                                                         G_PARAM_STATIC_NAME |
 182                                                         G_PARAM_STATIC_BLURB |
 183                                                         G_PARAM_STATIC_NICK));
 184 }
 185
 186 static void
 187 mechanism_free (Mechanism *m)
 188 {
 189   g_free (m);
 190 }
 191
 192 static void
 193 add_mechanism (GDBusAuth         *auth,
 194                GDBusAuthObserver *observer,
 195                GType              mechanism_type)
 196 {
 197   const gchar *name;
 198
 199   name = _g_dbus_auth_mechanism_get_name (mechanism_type);
 200   if (observer == NULL || g_dbus_auth_observer_allow_mechanism (observer, name))
 201     {
 202       Mechanism *m;
 203       m = g_new0 (Mechanism, 1);
 204       m->name = name;
 205       m->priority = _g_dbus_auth_mechanism_get_priority (mechanism_type);
 206       m->gtype = mechanism_type;
 207       auth->priv->available_mechanisms = g_list_prepend (auth->priv->available_mechanisms, m);
 208     }
 209 }
 210
 211 static gint
 212 mech_compare_func (Mechanism *a, Mechanism *b)
 213 {
 214   gint ret;
 215   /* ensure deterministic order */
 216   ret = b->priority - a->priority;
 217   if (ret == 0)
 218     ret = g_strcmp0 (b->name, a->name);
 219   return ret;
 220 }
 221
 222 static void
 223 _g_dbus_auth_init (GDBusAuth *auth)
 224 {
 225   auth->priv = _g_dbus_auth_get_instance_private (auth);
 226 }
 227
 228 static void
 229 _g_dbus_auth_add_mechs (GDBusAuth         *auth,
 230                         GDBusAuthObserver *observer)
 231 {
 232   /* TODO: trawl extension points */
 233   add_mechanism (auth, observer, G_TYPE_DBUS_AUTH_MECHANISM_ANON);
 234   add_mechanism (auth, observer, G_TYPE_DBUS_AUTH_MECHANISM_SHA1);
 235   add_mechanism (auth, observer, G_TYPE_DBUS_AUTH_MECHANISM_EXTERNAL);
 236
 237   auth->priv->available_mechanisms = g_list_sort (auth->priv->available_mechanisms,
 238                                                   (GCompareFunc) mech_compare_func);
 239 }
 240
 241 static GType
 242 find_mech_by_name (GDBusAuth *auth,
 243                    const gchar *name)
 244 {
 245   GType ret;
 246   GList *l;
 247
 248   ret = (GType) 0;
 249
 250   for (l = auth->priv->available_mechanisms; l != NULL; l = l->next)
 251     {
 252       Mechanism *m = l->data;
 253       if (g_strcmp0 (name, m->name) == 0)
 254         {
 255           ret = m->gtype;
 256           goto out;
 257         }
 258     }
 259
 260  out:
 261   return ret;
 262 }
 263
 264 GDBusAuth  *
 265 _g_dbus_auth_new (GIOStream *stream)
 266 {
 267   return g_object_new (G_TYPE_DBUS_AUTH,
 268                        "stream", stream,
 269                        NULL);
 270 }
 271
 272 /* ---------------------------------------------------------------------------------------------------- */
 273 /* like g_data_input_stream_read_line() but sets error if there's no content to read */
 274 static gchar *
 275 _my_g_data_input_stream_read_line (GDataInputStream  *dis,
 276                                    gsize             *out_line_length,
 277                                    GCancellable      *cancellable,
 278                                    GError           **error)
 279 {
 280   gchar *ret;
 281
 282   g_return_val_if_fail (error == NULL || *error == NULL, NULL);
 283
 284   ret = g_data_input_stream_read_line (dis,
 285                                        out_line_length,
 286                                        cancellable,
 287                                        error);
 288   if (ret == NULL && error != NULL && *error == NULL)
 289     {
 290       g_set_error_literal (error,
 291                            G_IO_ERROR,
 292                            G_IO_ERROR_FAILED,
 293                            _("Unexpected lack of content trying to read a line"));
 294     }
 295
 296   return ret;
 297 }
 298
 299 /* This function is to avoid situations like this
 300  *
 301  * BEGIN\r\nl\0\0\1...
 302  *
 303  * e.g. where we read into the first D-Bus message while waiting for
 304  * the final line from the client (TODO: file bug against gio for
 305  * this)
 306  */
 307 static gchar *
 308 _my_g_input_stream_read_line_safe (GInputStream  *i,
 309                                    gsize         *out_line_length,
 310                                    GCancellable  *cancellable,
 311                                    GError       **error)
 312 {
 313   GString *str;
 314   gchar c;
 315   gssize num_read;
 316   gboolean last_was_cr;
 317
 318   str = g_string_new (NULL);
 319
 320   last_was_cr = FALSE;
 321   while (TRUE)
 322     {
 323       num_read = g_input_stream_read (i,
 324                                       &c,
 325                                       1,
 326                                       cancellable,
 327                                       error);
 328       if (num_read == -1)
 329         goto fail;
 330       if (num_read == 0)
 331         {
 332           if (error != NULL && *error == NULL)
 333             {
 334               g_set_error_literal (error,
 335                                    G_IO_ERROR,
 336                                    G_IO_ERROR_FAILED,
 337                                    _("Unexpected lack of content trying to (safely) read a line"));
 338             }
 339           goto fail;
 340         }
 341
 342       g_string_append_c (str, (gint) c);
 343       if (last_was_cr)
 344         {
 345           if (c == 0x0a)
 346             {
 347               g_assert (str->len >= 2);
 348               g_string_set_size (str, str->len - 2);
 349               goto out;
 350             }
 351         }
 352       last_was_cr = (c == 0x0d);
 353     }
 354
 355  out:
 356   if (out_line_length != NULL)
 357     *out_line_length = str->len;
 358   return g_string_free (str, FALSE);
 359
 360  fail:
 361   g_assert (error == NULL || *error != NULL);
 362   g_string_free (str, TRUE);
 363   return NULL;
 364 }
 365
 366 /* ---------------------------------------------------------------------------------------------------- */
 367
 368 static void
 369 append_nibble (GString *s, gint val)
 370 {
 371   g_string_append_c (s, val >= 10 ? ('a' + val - 10) : ('0' + val));
 372 }
 373
 374 static gchar *
 375 hexdecode (const gchar  *str,
 376            gsize        *out_len,
 377            GError      **error)
 378 {
 379   gchar *ret;
 380   GString *s;
 381   guint n;
 382
 383   ret = NULL;
 384   s = g_string_new (NULL);
 385
 386   for (n = 0; str[n] != '\0'; n += 2)
 387     {
 388       gint upper_nibble;
 389       gint lower_nibble;
 390       guint value;
 391
 392       upper_nibble = g_ascii_xdigit_value (str[n]);
 393       lower_nibble = g_ascii_xdigit_value (str[n + 1]);
 394       if (upper_nibble == -1 || lower_nibble == -1)
 395         {
 396           g_set_error (error,
 397                        G_IO_ERROR,
 398                        G_IO_ERROR_FAILED,
 399                        "Error hexdecoding string '%s' around position %d",
 400                        str, n);
 401           goto out;
 402         }
 403       value = (upper_nibble<<4) | lower_nibble;
 404       g_string_append_c (s, value);
 405     }
 406
 407   ret = g_string_free (s, FALSE);
 408   s = NULL;
 409
 410  out:
 411   if (s != NULL)
 412     g_string_free (s, TRUE);
 413   return ret;
 414 }
 415
 416 /* TODO: take len */
 417 static gchar *
 418 hexencode (const gchar *str)
 419 {
 420   guint n;
 421   GString *s;
 422
 423   s = g_string_new (NULL);
 424   for (n = 0; str[n] != '\0'; n++)
 425     {
 426       gint val;
 427       gint upper_nibble;
 428       gint lower_nibble;
 429
 430       val = ((const guchar *) str)[n];
 431       upper_nibble = val >> 4;
 432       lower_nibble = val & 0x0f;
 433
 434       append_nibble (s, upper_nibble);
 435       append_nibble (s, lower_nibble);
 436     }
 437
 438   return g_string_free (s, FALSE);
 439 }
 440
 441 /* ---------------------------------------------------------------------------------------------------- */
 442
 443 static GDBusAuthMechanism *
 444 client_choose_mech_and_send_initial_response (GDBusAuth           *auth,
 445                                               GCredentials        *credentials_that_were_sent,
 446                                               const gchar* const  *supported_auth_mechs,
 447                                               GPtrArray           *attempted_auth_mechs,
 448                                               GDataOutputStream   *dos,
 449                                               GCancellable        *cancellable,
 450                                               GError             **error)
 451 {
 452   GDBusAuthMechanism *mech;
 453   GType auth_mech_to_use_gtype;
 454   guint n;
 455   guint m;
 456   gchar *initial_response;
 457   gsize initial_response_len;
 458   gchar *encoded;
 459   gchar *s;
 460
 461  again:
 462   mech = NULL;
 463
 464   debug_print ("CLIENT: Trying to choose mechanism");
 465
 466   /* find an authentication mechanism to try, if any */
 467   auth_mech_to_use_gtype = (GType) 0;
 468   for (n = 0; supported_auth_mechs[n] != NULL; n++)
 469     {
 470       gboolean attempted_already;
 471       attempted_already = FALSE;
 472       for (m = 0; m < attempted_auth_mechs->len; m++)
 473         {
 474           if (g_strcmp0 (supported_auth_mechs[n], attempted_auth_mechs->pdata[m]) == 0)
 475             {
 476               attempted_already = TRUE;
 477               break;
 478             }
 479         }
 480       if (!attempted_already)
 481         {
 482           auth_mech_to_use_gtype = find_mech_by_name (auth, supported_auth_mechs[n]);
 483           if (auth_mech_to_use_gtype != (GType) 0)
 484             break;
 485         }
 486     }
 487
 488   if (auth_mech_to_use_gtype == (GType) 0)
 489     {
 490       guint n;
 491       gchar *available;
 492       GString *tried_str;
 493
 494       debug_print ("CLIENT: Exhausted all available mechanisms");
 495
 496       available = g_strjoinv (", ", (gchar **) supported_auth_mechs);
 497
 498       tried_str = g_string_new (NULL);
 499       for (n = 0; n < attempted_auth_mechs->len; n++)
 500         {
 501           if (n > 0)
 502             g_string_append (tried_str, ", ");
 503           g_string_append (tried_str, attempted_auth_mechs->pdata[n]);
 504         }
 505       g_set_error (error,
 506                    G_IO_ERROR,
 507                    G_IO_ERROR_FAILED,
 508                    _("Exhausted all available authentication mechanisms (tried: %s) (available: %s)"),
 509                    tried_str->str,
 510                    available);
 511       g_string_free (tried_str, TRUE);
 512       g_free (available);
 513       goto out;
 514     }
 515
 516   /* OK, decided on a mechanism - let's do this thing */
 517   mech = g_object_new (auth_mech_to_use_gtype,
 518                        "stream", auth->priv->stream,
 519                        "credentials", credentials_that_were_sent,
 520                        NULL);
 521   debug_print ("CLIENT: Trying mechanism '%s'", _g_dbus_auth_mechanism_get_name (auth_mech_to_use_gtype));
 522   g_ptr_array_add (attempted_auth_mechs, (gpointer) _g_dbus_auth_mechanism_get_name (auth_mech_to_use_gtype));
 523
 524   /* the auth mechanism may not be supported
 525    * (for example, EXTERNAL only works if credentials were exchanged)
 526    */
 527   if (!_g_dbus_auth_mechanism_is_supported (mech))
 528     {
 529       debug_print ("CLIENT: Mechanism '%s' says it is not supported", _g_dbus_auth_mechanism_get_name (auth_mech_to_use_gtype));
 530       g_object_unref (mech);
 531       mech = NULL;
 532       goto again;
 533     }
 534
 535   initial_response_len = -1;
 536   initial_response = _g_dbus_auth_mechanism_client_initiate (mech,
 537                                                              &initial_response_len);
 538 #if 0
 539   g_printerr ("using auth mechanism with name '%s' of type '%s' with initial response '%s'\n",
 540               _g_dbus_auth_mechanism_get_name (auth_mech_to_use_gtype),
 541               g_type_name (G_TYPE_FROM_INSTANCE (mech)),
 542               initial_response);
 543 #endif
 544   if (initial_response != NULL)
 545     {
 546       //g_printerr ("initial_response = '%s'\n", initial_response);
 547       encoded = hexencode (initial_response);
 548       s = g_strdup_printf ("AUTH %s %s\r\n",
 549                            _g_dbus_auth_mechanism_get_name (auth_mech_to_use_gtype),
 550                            encoded);
 551       g_free (initial_response);
 552       g_free (encoded);
 553     }
 554   else
 555     {
 556       s = g_strdup_printf ("AUTH %s\r\n", _g_dbus_auth_mechanism_get_name (auth_mech_to_use_gtype));
 557     }
 558   debug_print ("CLIENT: writing '%s'", s);
 559   if (!g_data_output_stream_put_string (dos, s, cancellable, error))
 560     {
 561       g_object_unref (mech);
 562       mech = NULL;
 563       g_free (s);
 564       goto out;
 565     }
 566   g_free (s);
 567
 568  out:
 569   return mech;
 570 }
 571
 572
 573 /* ---------------------------------------------------------------------------------------------------- */
 574
 575 typedef enum
 576 {
 577   CLIENT_STATE_WAITING_FOR_DATA,
 578   CLIENT_STATE_WAITING_FOR_OK,
 579   CLIENT_STATE_WAITING_FOR_REJECT,
 580   CLIENT_STATE_WAITING_FOR_AGREE_UNIX_FD
 581 } ClientState;
 582
 583 gchar *
 584 _g_dbus_auth_run_client (GDBusAuth     *auth,
 585                          GDBusAuthObserver     *observer,
 586                          GDBusCapabilityFlags offered_capabilities,
 587                          GDBusCapabilityFlags *out_negotiated_capabilities,
 588                          GCancellable  *cancellable,
 589                          GError       **error)
 590 {
 591   gchar *s;
 592   GDataInputStream *dis;
 593   GDataOutputStream *dos;
 594   GCredentials *credentials;
 595   gchar *ret_guid;
 596   gchar *line;
 597   gsize line_length;
 598   gchar **supported_auth_mechs;
 599   GPtrArray *attempted_auth_mechs;
 600   GDBusAuthMechanism *mech;
 601   ClientState state;
 602   GDBusCapabilityFlags negotiated_capabilities;
 603
 604   debug_print ("CLIENT: initiating");
 605
 606   _g_dbus_auth_add_mechs (auth, observer);
 607
 608   ret_guid = NULL;
 609   supported_auth_mechs = NULL;
 610   attempted_auth_mechs = g_ptr_array_new ();
 611   mech = NULL;
 612   negotiated_capabilities = 0;
 613   credentials = NULL;
 614
 615   dis = G_DATA_INPUT_STREAM (g_data_input_stream_new (g_io_stream_get_input_stream (auth->priv->stream)));
 616   dos = G_DATA_OUTPUT_STREAM (g_data_output_stream_new (g_io_stream_get_output_stream (auth->priv->stream)));
 617   g_filter_input_stream_set_close_base_stream (G_FILTER_INPUT_STREAM (dis), FALSE);
 618   g_filter_output_stream_set_close_base_stream (G_FILTER_OUTPUT_STREAM (dos), FALSE);
 619
 620   g_data_input_stream_set_newline_type (dis, G_DATA_STREAM_NEWLINE_TYPE_CR_LF);
 621
 622 #ifdef G_OS_UNIX
 623   if (G_IS_UNIX_CONNECTION (auth->priv->stream))
 624     {
 625       credentials = g_credentials_new ();
 626       if (!g_unix_connection_send_credentials (G_UNIX_CONNECTION (auth->priv->stream),
 627                                                cancellable,
 628                                                error))
 629         goto out;
 630     }
 631   else
 632     {
 633       if (!g_data_output_stream_put_byte (dos, '\0', cancellable, error))
 634         goto out;
 635     }
 636 #else
 637   if (!g_data_output_stream_put_byte (dos, '\0', cancellable, error))
 638     goto out;
 639 #endif
 640
 641   if (credentials != NULL)
 642     {
 643       if (G_UNLIKELY (_g_dbus_debug_authentication ()))
 644         {
 645           s = g_credentials_to_string (credentials);
 646           debug_print ("CLIENT: sent credentials '%s'", s);
 647           g_free (s);
 648         }
 649     }
 650   else
 651     {
 652       debug_print ("CLIENT: didn't send any credentials");
 653     }
 654
 655   /* TODO: to reduce roundtrips, try to pick an auth mechanism to start with */
 656
 657   /* Get list of supported authentication mechanisms */
 658   s = "AUTH\r\n";
 659   debug_print ("CLIENT: writing '%s'", s);
 660   if (!g_data_output_stream_put_string (dos, s, cancellable, error))
 661     goto out;
 662   state = CLIENT_STATE_WAITING_FOR_REJECT;
 663
 664   while (TRUE)
 665     {
 666       switch (state)
 667         {
 668         case CLIENT_STATE_WAITING_FOR_REJECT:
 669           debug_print ("CLIENT: WaitingForReject");
 670           line = _my_g_data_input_stream_read_line (dis, &line_length, cancellable, error);
 671           if (line == NULL)
 672             goto out;
 673           debug_print ("CLIENT: WaitingForReject, read '%s'", line);
 674
 675         choose_mechanism:
 676           if (!g_str_has_prefix (line, "REJECTED "))
 677             {
 678               g_set_error (error,
 679                            G_IO_ERROR,
 680                            G_IO_ERROR_FAILED,
 681                            "In WaitingForReject: Expected 'REJECTED am1 am2 ... amN', got '%s'",
 682                            line);
 683               g_free (line);
 684               goto out;
 685             }
 686           if (supported_auth_mechs == NULL)
 687             {
 688               supported_auth_mechs = g_strsplit (line + sizeof ("REJECTED ") - 1, " ", 0);
 689 #if 0
 690               for (n = 0; supported_auth_mechs != NULL && supported_auth_mechs[n] != NULL; n++)
 691                 g_printerr ("supported_auth_mechs[%d] = '%s'\n", n, supported_auth_mechs[n]);
 692 #endif
 693             }
 694           g_free (line);
 695           mech = client_choose_mech_and_send_initial_response (auth,
 696                                                                credentials,
 697                                                                (const gchar* const *) supported_auth_mechs,
 698                                                                attempted_auth_mechs,
 699                                                                dos,
 700                                                                cancellable,
 701                                                                error);
 702           if (mech == NULL)
 703             goto out;
 704           if (_g_dbus_auth_mechanism_client_get_state (mech) == G_DBUS_AUTH_MECHANISM_STATE_WAITING_FOR_DATA)
 705             state = CLIENT_STATE_WAITING_FOR_DATA;
 706           else
 707             state = CLIENT_STATE_WAITING_FOR_OK;
 708           break;
 709
 710         case CLIENT_STATE_WAITING_FOR_OK:
 711           debug_print ("CLIENT: WaitingForOK");
 712           line = _my_g_data_input_stream_read_line (dis, &line_length, cancellable, error);
 713           if (line == NULL)
 714             goto out;
 715           debug_print ("CLIENT: WaitingForOK, read '%s'", line);
 716           if (g_str_has_prefix (line, "OK "))
 717             {
 718               if (!g_dbus_is_guid (line + 3))
 719                 {
 720                   g_set_error (error,
 721                                G_IO_ERROR,
 722                                G_IO_ERROR_FAILED,
 723                                "Invalid OK response '%s'",
 724                                line);
 725                   g_free (line);
 726                   goto out;
 727                 }
 728               ret_guid = g_strdup (line + 3);
 729               g_free (line);
 730
 731               if (offered_capabilities & G_DBUS_CAPABILITY_FLAGS_UNIX_FD_PASSING)
 732                 {
 733                   s = "NEGOTIATE_UNIX_FD\r\n";
 734                   debug_print ("CLIENT: writing '%s'", s);
 735                   if (!g_data_output_stream_put_string (dos, s, cancellable, error))
 736                     goto out;
 737                   state = CLIENT_STATE_WAITING_FOR_AGREE_UNIX_FD;
 738                 }
 739               else
 740                 {
 741                   s = "BEGIN\r\n";
 742                   debug_print ("CLIENT: writing '%s'", s);
 743                   if (!g_data_output_stream_put_string (dos, s, cancellable, error))
 744                     goto out;
 745                   /* and we're done! */
 746                   goto out;
 747                 }
 748             }
 749           else if (g_str_has_prefix (line, "REJECTED "))
 750             {
 751               goto choose_mechanism;
 752             }
 753           else
 754             {
 755               /* TODO: handle other valid responses */
 756               g_set_error (error,
 757                            G_IO_ERROR,
 758                            G_IO_ERROR_FAILED,
 759                            "In WaitingForOk: unexpected response '%s'",
 760                            line);
 761               g_free (line);
 762               goto out;
 763             }
 764           break;
 765
 766         case CLIENT_STATE_WAITING_FOR_AGREE_UNIX_FD:
 767           debug_print ("CLIENT: WaitingForAgreeUnixFD");
 768           line = _my_g_data_input_stream_read_line (dis, &line_length, cancellable, error);
 769           if (line == NULL)
 770             goto out;
 771           debug_print ("CLIENT: WaitingForAgreeUnixFD, read='%s'", line);
 772           if (g_strcmp0 (line, "AGREE_UNIX_FD") == 0)
 773             {
 774               g_free (line);
 775               negotiated_capabilities |= G_DBUS_CAPABILITY_FLAGS_UNIX_FD_PASSING;
 776               s = "BEGIN\r\n";
 777               debug_print ("CLIENT: writing '%s'", s);
 778               if (!g_data_output_stream_put_string (dos, s, cancellable, error))
 779                 goto out;
 780               /* and we're done! */
 781               goto out;
 782             }
 783           else if (g_str_has_prefix (line, "ERROR") && (line[5] == 0 || g_ascii_isspace (line[5])))
 784             {
 785               //g_strstrip (line + 5); g_debug ("bah, no unix_fd: '%s'", line + 5);
 786               g_free (line);
 787               s = "BEGIN\r\n";
 788               debug_print ("CLIENT: writing '%s'", s);
 789               if (!g_data_output_stream_put_string (dos, s, cancellable, error))
 790                 goto out;
 791               /* and we're done! */
 792               goto out;
 793             }
 794           else
 795             {
 796               /* TODO: handle other valid responses */
 797               g_set_error (error,
 798                            G_IO_ERROR,
 799                            G_IO_ERROR_FAILED,
 800                            "In WaitingForAgreeUnixFd: unexpected response '%s'",
 801                            line);
 802               g_free (line);
 803               goto out;
 804             }
 805           break;
 806
 807         case CLIENT_STATE_WAITING_FOR_DATA:
 808           debug_print ("CLIENT: WaitingForData");
 809           line = _my_g_data_input_stream_read_line (dis, &line_length, cancellable, error);
 810           if (line == NULL)
 811             goto out;
 812           debug_print ("CLIENT: WaitingForData, read='%s'", line);
 813           if (g_str_has_prefix (line, "DATA "))
 814             {
 815               gchar *encoded;
 816               gchar *decoded_data;
 817               gsize decoded_data_len = 0;
 818
 819               encoded = g_strdup (line + 5);
 820               g_free (line);
 821               g_strstrip (encoded);
 822               decoded_data = hexdecode (encoded, &decoded_data_len, error);
 823               g_free (encoded);
 824               if (decoded_data == NULL)
 825                 {
 826                   g_prefix_error (error, "DATA response is malformed: ");
 827                   /* invalid encoding, disconnect! */
 828                   goto out;
 829                 }
 830               _g_dbus_auth_mechanism_client_data_receive (mech, decoded_data, decoded_data_len);
 831               g_free (decoded_data);
 832
 833               if (_g_dbus_auth_mechanism_client_get_state (mech) == G_DBUS_AUTH_MECHANISM_STATE_HAVE_DATA_TO_SEND)
 834                 {
 835                   gchar *data;
 836                   gsize data_len;
 837                   gchar *encoded_data;
 838                   data = _g_dbus_auth_mechanism_client_data_send (mech, &data_len);
 839                   encoded_data = hexencode (data);
 840                   s = g_strdup_printf ("DATA %s\r\n", encoded_data);
 841                   g_free (encoded_data);
 842                   g_free (data);
 843                   debug_print ("CLIENT: writing '%s'", s);
 844                   if (!g_data_output_stream_put_string (dos, s, cancellable, error))
 845                     {
 846                       g_free (s);
 847                       goto out;
 848                     }
 849                   g_free (s);
 850                 }
 851               state = CLIENT_STATE_WAITING_FOR_OK;
 852             }
 853           else if (g_str_has_prefix (line, "REJECTED "))
 854             {
 855               /* could be the chosen authentication method just doesn't work. Try
 856                * another one...
 857                */
 858               goto choose_mechanism;
 859             }
 860           else
 861             {
 862               g_set_error (error,
 863                            G_IO_ERROR,
 864                            G_IO_ERROR_FAILED,
 865                            "In WaitingForData: unexpected response '%s'",
 866                            line);
 867               g_free (line);
 868               goto out;
 869             }
 870           break;
 871
 872         default:
 873           g_assert_not_reached ();
 874           break;
 875         }
 876
 877     }; /* main authentication client loop */
 878
 879  out:
 880   if (mech != NULL)
 881     g_object_unref (mech);
 882   g_ptr_array_unref (attempted_auth_mechs);
 883   g_strfreev (supported_auth_mechs);
 884   g_object_unref (dis);
 885   g_object_unref (dos);
 886
 887   /* ensure return value is NULL if error is set */
 888   if (error != NULL && *error != NULL)
 889     {
 890       g_free (ret_guid);
 891       ret_guid = NULL;
 892     }
 893
 894   if (ret_guid != NULL)
 895     {
 896       if (out_negotiated_capabilities != NULL)
 897         *out_negotiated_capabilities = negotiated_capabilities;
 898     }
 899
 900   if (credentials != NULL)
 901     g_object_unref (credentials);
 902
 903   debug_print ("CLIENT: Done, authenticated=%d", ret_guid != NULL);
 904
 905   return ret_guid;
 906 }
 907
 908 /* ---------------------------------------------------------------------------------------------------- */
 909
 910 static gchar *
 911 get_auth_mechanisms (GDBusAuth     *auth,
 912                      gboolean       allow_anonymous,
 913                      const gchar   *prefix,
 914                      const gchar   *suffix,
 915                      const gchar   *separator)
 916 {
 917   GList *l;
 918   GString *str;
 919   gboolean need_sep;
 920
 921   str = g_string_new (prefix);
 922   need_sep = FALSE;
 923   for (l = auth->priv->available_mechanisms; l != NULL; l = l->next)
 924     {
 925       Mechanism *m = l->data;
 926
 927       if (!allow_anonymous && g_strcmp0 (m->name, "ANONYMOUS") == 0)
 928         continue;
 929
 930       if (need_sep)
 931         g_string_append (str, separator);
 932       g_string_append (str, m->name);
 933       need_sep = TRUE;
 934     }
 935
 936   g_string_append (str, suffix);
 937   return g_string_free (str, FALSE);
 938 }
 939
 940
 941 typedef enum
 942 {
 943   SERVER_STATE_WAITING_FOR_AUTH,
 944   SERVER_STATE_WAITING_FOR_DATA,
 945   SERVER_STATE_WAITING_FOR_BEGIN
 946 } ServerState;
 947
 948 gboolean
 949 _g_dbus_auth_run_server (GDBusAuth              *auth,
 950                          GDBusAuthObserver      *observer,
 951                          const gchar            *guid,
 952                          gboolean                allow_anonymous,
 953                          GDBusCapabilityFlags    offered_capabilities,
 954                          GDBusCapabilityFlags   *out_negotiated_capabilities,
 955                          GCredentials          **out_received_credentials,
 956                          GCancellable           *cancellable,
 957                          GError                **error)
 958 {
 959   gboolean ret;
 960   ServerState state;
 961   GDataInputStream *dis;
 962   GDataOutputStream *dos;
 963   GError *local_error;
 964   guchar byte;
 965   gchar *line;
 966   gsize line_length;
 967   GDBusAuthMechanism *mech;
 968   gchar *s;
 969   GDBusCapabilityFlags negotiated_capabilities;
 970   GCredentials *credentials;
 971
 972   debug_print ("SERVER: initiating");
 973
 974   _g_dbus_auth_add_mechs (auth, observer);
 975
 976   ret = FALSE;
 977   dis = NULL;
 978   dos = NULL;
 979   mech = NULL;
 980   negotiated_capabilities = 0;
 981   credentials = NULL;
 982
 983   if (!g_dbus_is_guid (guid))
 984     {
 985       g_set_error (error,
 986                    G_IO_ERROR,
 987                    G_IO_ERROR_FAILED,
 988                    "The given guid '%s' is not valid",
 989                    guid);
 990       goto out;
 991     }
 992
 993   dis = G_DATA_INPUT_STREAM (g_data_input_stream_new (g_io_stream_get_input_stream (auth->priv->stream)));
 994   dos = G_DATA_OUTPUT_STREAM (g_data_output_stream_new (g_io_stream_get_output_stream (auth->priv->stream)));
 995   g_filter_input_stream_set_close_base_stream (G_FILTER_INPUT_STREAM (dis), FALSE);
 996   g_filter_output_stream_set_close_base_stream (G_FILTER_OUTPUT_STREAM (dos), FALSE);
 997
 998   g_data_input_stream_set_newline_type (dis, G_DATA_STREAM_NEWLINE_TYPE_CR_LF);
 999
1000   /* first read the NUL-byte (TODO: read credentials if using a unix domain socket) */
1001 #ifdef G_OS_UNIX
1002   if (G_IS_UNIX_CONNECTION (auth->priv->stream))
1003     {
1004       local_error = NULL;
1005       credentials = g_unix_connection_receive_credentials (G_UNIX_CONNECTION (auth->priv->stream),
1006                                                            cancellable,
1007                                                            &local_error);
1008       if (credentials == NULL && !g_error_matches (local_error, G_IO_ERROR, G_IO_ERROR_NOT_SUPPORTED))
1009         {
1010           g_propagate_error (error, local_error);
1011           goto out;
1012         }
1013     }
1014   else
1015     {
1016       local_error = NULL;
1017       byte = g_data_input_stream_read_byte (dis, cancellable, &local_error);
1018       byte = byte; /* To avoid -Wunused-but-set-variable */
1019       if (local_error != NULL)
1020         {
1021           g_propagate_error (error, local_error);
1022           goto out;
1023         }
1024     }
1025 #else
1026   local_error = NULL;
1027   byte = g_data_input_stream_read_byte (dis, cancellable, &local_error);
1028   byte = byte; /* To avoid -Wunused-but-set-variable */
1029   if (local_error != NULL)
1030     {
1031       g_propagate_error (error, local_error);
1032       goto out;
1033     }
1034 #endif
1035   if (credentials != NULL)
1036     {
1037       if (G_UNLIKELY (_g_dbus_debug_authentication ()))
1038         {
1039           s = g_credentials_to_string (credentials);
1040           debug_print ("SERVER: received credentials '%s'", s);
1041           g_free (s);
1042         }
1043     }
1044   else
1045     {
1046       debug_print ("SERVER: didn't receive any credentials");
1047     }
1048
1049   state = SERVER_STATE_WAITING_FOR_AUTH;
1050   while (TRUE)
1051     {
1052       switch (state)
1053         {
1054         case SERVER_STATE_WAITING_FOR_AUTH:
1055           debug_print ("SERVER: WaitingForAuth");
1056           line = _my_g_data_input_stream_read_line (dis, &line_length, cancellable, error);
1057           debug_print ("SERVER: WaitingForAuth, read '%s'", line);
1058           if (line == NULL)
1059             goto out;
1060           if (g_strcmp0 (line, "AUTH") == 0)
1061             {
1062               s = get_auth_mechanisms (auth, allow_anonymous, "REJECTED ", "\r\n", " ");
1063               debug_print ("SERVER: writing '%s'", s);
1064               if (!g_data_output_stream_put_string (dos, s, cancellable, error))
1065                 {
1066                   g_free (s);
1067                   goto out;
1068                 }
1069               g_free (s);
1070               g_free (line);
1071             }
1072           else if (g_str_has_prefix (line, "AUTH "))
1073             {
1074               gchar **tokens;
1075               const gchar *encoded;
1076               const gchar *mech_name;
1077               GType auth_mech_to_use_gtype;
1078
1079               tokens = g_strsplit (line, " ", 0);
1080               g_free (line);
1081
1082               switch (g_strv_length (tokens))
1083                 {
1084                 case 2:
1085                   /* no initial response */
1086                   mech_name = tokens[1];
1087                   encoded = NULL;
1088                   break;
1089
1090                 case 3:
1091                   /* initial response */
1092                   mech_name = tokens[1];
1093                   encoded = tokens[2];
1094                   break;
1095
1096                 default:
1097                   g_set_error (error,
1098                                G_IO_ERROR,
1099                                G_IO_ERROR_FAILED,
1100                                "Unexpected line '%s' while in WaitingForAuth state",
1101                                line);
1102                   g_strfreev (tokens);
1103                   goto out;
1104                 }
1105
1106               /* TODO: record that the client has attempted to use this mechanism */
1107               //g_debug ("client is trying '%s'", mech_name);
1108
1109               auth_mech_to_use_gtype = find_mech_by_name (auth, mech_name);
1110               if ((auth_mech_to_use_gtype == (GType) 0) ||
1111                   (!allow_anonymous && g_strcmp0 (mech_name, "ANONYMOUS") == 0))
1112                 {
1113                   /* We don't support this auth mechanism */
1114                   g_strfreev (tokens);
1115                   s = get_auth_mechanisms (auth, allow_anonymous, "REJECTED ", "\r\n", " ");
1116                   debug_print ("SERVER: writing '%s'", s);
1117                   if (!g_data_output_stream_put_string (dos, s, cancellable, error))
1118                     {
1119                       g_free (s);
1120                       goto out;
1121                     }
1122                   g_free (s);
1123
1124                   /* stay in WAITING FOR AUTH */
1125                   state = SERVER_STATE_WAITING_FOR_AUTH;
1126                 }
1127               else
1128                 {
1129                   gchar *initial_response;
1130                   gsize initial_response_len;
1131
1132                   mech = g_object_new (auth_mech_to_use_gtype,
1133                                        "stream", auth->priv->stream,
1134                                        "credentials", credentials,
1135                                        NULL);
1136
1137                   initial_response = NULL;
1138                   initial_response_len = 0;
1139                   if (encoded != NULL)
1140                     {
1141                       initial_response = hexdecode (encoded, &initial_response_len, error);
1142                       if (initial_response == NULL)
1143                         {
1144                           g_prefix_error (error, "Initial response is malformed: ");
1145                           /* invalid encoding, disconnect! */
1146                           g_strfreev (tokens);
1147                           goto out;
1148                         }
1149                     }
1150
1151                   _g_dbus_auth_mechanism_server_initiate (mech,
1152                                                           initial_response,
1153                                                           initial_response_len);
1154                   g_free (initial_response);
1155                   g_strfreev (tokens);
1156
1157                 change_state:
1158                   switch (_g_dbus_auth_mechanism_server_get_state (mech))
1159                     {
1160                     case G_DBUS_AUTH_MECHANISM_STATE_ACCEPTED:
1161                       if (observer != NULL &&
1162                           !g_dbus_auth_observer_authorize_authenticated_peer (observer,
1163                                                                               auth->priv->stream,
1164                                                                               credentials))
1165                         {
1166                           /* disconnect */
1167                           g_set_error_literal (error,
1168                                                G_IO_ERROR,
1169                                                G_IO_ERROR_FAILED,
1170                                                _("Cancelled via GDBusAuthObserver::authorize-authenticated-peer"));
1171                           goto out;
1172                         }
1173                       else
1174                         {
1175                           s = g_strdup_printf ("OK %s\r\n", guid);
1176                           debug_print ("SERVER: writing '%s'", s);
1177                           if (!g_data_output_stream_put_string (dos, s, cancellable, error))
1178                             {
1179                               g_free (s);
1180                               goto out;
1181                             }
1182                           g_free (s);
1183                           state = SERVER_STATE_WAITING_FOR_BEGIN;
1184                         }
1185                       break;
1186
1187                     case G_DBUS_AUTH_MECHANISM_STATE_REJECTED:
1188                       s = get_auth_mechanisms (auth, allow_anonymous, "REJECTED ", "\r\n", " ");
1189                       debug_print ("SERVER: writing '%s'", s);
1190                       if (!g_data_output_stream_put_string (dos, s, cancellable, error))
1191                         {
1192                           g_free (s);
1193                           goto out;
1194                         }
1195                       g_free (s);
1196                       state = SERVER_STATE_WAITING_FOR_AUTH;
1197                       break;
1198
1199                     case G_DBUS_AUTH_MECHANISM_STATE_WAITING_FOR_DATA:
1200                       state = SERVER_STATE_WAITING_FOR_DATA;
1201                       break;
1202
1203                     case G_DBUS_AUTH_MECHANISM_STATE_HAVE_DATA_TO_SEND:
1204                       {
1205                         gchar *data;
1206                         gsize data_len;
1207                         gchar *encoded_data;
1208                         data = _g_dbus_auth_mechanism_server_data_send (mech, &data_len);
1209                         encoded_data = hexencode (data);
1210                         s = g_strdup_printf ("DATA %s\r\n", encoded_data);
1211                         g_free (encoded_data);
1212                         g_free (data);
1213                         debug_print ("SERVER: writing '%s'", s);
1214                         if (!g_data_output_stream_put_string (dos, s, cancellable, error))
1215                           {
1216                             g_free (s);
1217                             goto out;
1218                           }
1219                         g_free (s);
1220                       }
1221                       goto change_state;
1222                       break;
1223
1224                     default:
1225                       /* TODO */
1226                       g_assert_not_reached ();
1227                       break;
1228                     }
1229                 }
1230             }
1231           else
1232             {
1233               g_set_error (error,
1234                            G_IO_ERROR,
1235                            G_IO_ERROR_FAILED,
1236                            "Unexpected line '%s' while in WaitingForAuth state",
1237                            line);
1238               g_free (line);
1239               goto out;
1240             }
1241           break;
1242
1243         case SERVER_STATE_WAITING_FOR_DATA:
1244           debug_print ("SERVER: WaitingForData");
1245           line = _my_g_data_input_stream_read_line (dis, &line_length, cancellable, error);
1246           debug_print ("SERVER: WaitingForData, read '%s'", line);
1247           if (line == NULL)
1248             goto out;
1249           if (g_str_has_prefix (line, "DATA "))
1250             {
1251               gchar *encoded;
1252               gchar *decoded_data;
1253               gsize decoded_data_len = 0;
1254
1255               encoded = g_strdup (line + 5);
1256               g_free (line);
1257               g_strstrip (encoded);
1258               decoded_data = hexdecode (encoded, &decoded_data_len, error);
1259               g_free (encoded);
1260               if (decoded_data == NULL)
1261                 {
1262                   g_prefix_error (error, "DATA response is malformed: ");
1263                   /* invalid encoding, disconnect! */
1264                   goto out;
1265                 }
1266               _g_dbus_auth_mechanism_server_data_receive (mech, decoded_data, decoded_data_len);
1267               g_free (decoded_data);
1268               /* oh man, this goto-crap is so ugly.. really need to rewrite the state machine */
1269               goto change_state;
1270             }
1271           else
1272             {
1273               g_set_error (error,
1274                            G_IO_ERROR,
1275                            G_IO_ERROR_FAILED,
1276                            "Unexpected line '%s' while in WaitingForData state",
1277                            line);
1278               g_free (line);
1279             }
1280           goto out;
1281
1282         case SERVER_STATE_WAITING_FOR_BEGIN:
1283           debug_print ("SERVER: WaitingForBegin");
1284           /* Use extremely slow (but reliable) line reader - this basically
1285            * does a recvfrom() system call per character
1286            *
1287            * (the problem with using GDataInputStream's read_line is that because of
1288            * buffering it might start reading into the first D-Bus message that
1289            * appears after "BEGIN\r\n"....)
1290            */
1291           line = _my_g_input_stream_read_line_safe (g_io_stream_get_input_stream (auth->priv->stream),
1292                                                     &line_length,
1293                                                     cancellable,
1294                                                     error);
1295           debug_print ("SERVER: WaitingForBegin, read '%s'", line);
1296           if (line == NULL)
1297             goto out;
1298           if (g_strcmp0 (line, "BEGIN") == 0)
1299             {
1300               /* YAY, done! */
1301               ret = TRUE;
1302               g_free (line);
1303               goto out;
1304             }
1305           else if (g_strcmp0 (line, "NEGOTIATE_UNIX_FD") == 0)
1306             {
1307               g_free (line);
1308               if (offered_capabilities & G_DBUS_CAPABILITY_FLAGS_UNIX_FD_PASSING)
1309                 {
1310                   negotiated_capabilities |= G_DBUS_CAPABILITY_FLAGS_UNIX_FD_PASSING;
1311                   s = "AGREE_UNIX_FD\r\n";
1312                   debug_print ("SERVER: writing '%s'", s);
1313                   if (!g_data_output_stream_put_string (dos, s, cancellable, error))
1314                     goto out;
1315                 }
1316               else
1317                 {
1318                   s = "ERROR \"fd passing not offered\"\r\n";
1319                   debug_print ("SERVER: writing '%s'", s);
1320                   if (!g_data_output_stream_put_string (dos, s, cancellable, error))
1321                     goto out;
1322                 }
1323             }
1324           else
1325             {
1326               g_debug ("Unexpected line '%s' while in WaitingForBegin state", line);
1327               g_free (line);
1328               s = "ERROR \"Unknown Command\"\r\n";
1329               debug_print ("SERVER: writing '%s'", s);
1330               if (!g_data_output_stream_put_string (dos, s, cancellable, error))
1331                 goto out;
1332             }
1333           break;
1334
1335         default:
1336           g_assert_not_reached ();
1337           break;
1338         }
1339     }
1340
1341
1342   g_set_error_literal (error,
1343                        G_IO_ERROR,
1344                        G_IO_ERROR_FAILED,
1345                        "Not implemented (server)");
1346
1347  out:
1348   if (mech != NULL)
1349     g_object_unref (mech);
1350   if (dis != NULL)
1351     g_object_unref (dis);
1352   if (dos != NULL)
1353     g_object_unref (dos);
1354
1355   /* ensure return value is FALSE if error is set */
1356   if (error != NULL && *error != NULL)
1357     {
1358       ret = FALSE;
1359     }
1360
1361   if (ret)
1362     {
1363       if (out_negotiated_capabilities != NULL)
1364         *out_negotiated_capabilities = negotiated_capabilities;
1365       if (out_received_credentials != NULL)
1366         *out_received_credentials = credentials != NULL ? g_object_ref (credentials) : NULL;
1367     }
1368
1369   if (credentials != NULL)
1370     g_object_unref (credentials);
1371
1372   debug_print ("SERVER: Done, authenticated=%d", ret);
1373
1374   return ret;
1375 }
1376
1377 /* ---------------------------------------------------------------------------------------------------- */