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, write to the
  17  * Free Software Foundation, Inc., 59 Temple Place, Suite 330,
  18  * Boston, MA 02111-1307, USA.
  19  *
  20  * Author: David Zeuthen <davidz@redhat.com>
  21  */
  22
  23 #include "config.h"
  24
  25 #include "gdbusauth.h"
  26
  27 #include "gdbusauthmechanismanon.h"
  28 #include "gdbusauthmechanismexternal.h"
  29 #include "gdbusauthmechanismsha1.h"
  30 #include "gdbusauthobserver.h"
  31
  32 #include "gdbuserror.h"
  33 #include "gdbusutils.h"
  34 #include "gioenumtypes.h"
  35 #include "gcredentials.h"
  36 #include "gdbusprivate.h"
  37 #include "giostream.h"
  38 #include "gdatainputstream.h"
  39 #include "gdataoutputstream.h"
  40
  41 #ifdef G_OS_UNIX
  42 #include <sys/types.h>
  43 #include <sys/socket.h>
  44 #include "gunixconnection.h"
  45 #include "gunixcredentialsmessage.h"
  46 #endif
  47
  48 #include "glibintl.h"
  49
  50 static void
  51 debug_print (const gchar *message, ...)
  52 {
  53   if (G_UNLIKELY (_g_dbus_debug_authentication ()))
  54     {
  55       gchar *s;
  56       GString *str;
  57       va_list var_args;
  58       guint n;
  59
  60       _g_dbus_debug_print_lock ();
  61
  62       va_start (var_args, message);
  63       s = g_strdup_vprintf (message, var_args);
  64       va_end (var_args);
  65
  66       str = g_string_new (NULL);
  67       for (n = 0; s[n] != '\0'; n++)
  68         {
  69           if (G_UNLIKELY (s[n] == '\r'))
  70             g_string_append (str, "\\r");
  71           else if (G_UNLIKELY (s[n] == '\n'))
  72             g_string_append (str, "\\n");
  73           else
  74             g_string_append_c (str, s[n]);
  75         }
  76       g_print ("GDBus-debug:Auth: %s\n", str->str);
  77       g_string_free (str, TRUE);
  78       g_free (s);
  79
  80       _g_dbus_debug_print_unlock ();
  81     }
  82 }
  83
  84 typedef struct
  85 {
  86   const gchar *name;
  87   gint priority;
  88   GType gtype;
  89 } Mechanism;
  90
  91 static void mechanism_free (Mechanism *m);
  92
  93 struct _GDBusAuthPrivate
  94 {
  95   GIOStream *stream;
  96
  97   /* A list of available Mechanism, sorted according to priority  */
  98   GList *available_mechanisms;
  99 };
 100
 101 enum
 102 {
 103   PROP_0,
 104   PROP_STREAM
 105 };
 106
 107 G_DEFINE_TYPE (GDBusAuth, _g_dbus_auth, G_TYPE_OBJECT);
 108
 109 /* ---------------------------------------------------------------------------------------------------- */
 110
 111 static void
 112 _g_dbus_auth_finalize (GObject *object)
 113 {
 114   GDBusAuth *auth = G_DBUS_AUTH (object);
 115
 116   if (auth->priv->stream != NULL)
 117     g_object_unref (auth->priv->stream);
 118   g_list_free_full (auth->priv->available_mechanisms, (GDestroyNotify) mechanism_free);
 119
 120   if (G_OBJECT_CLASS (_g_dbus_auth_parent_class)->finalize != NULL)
 121     G_OBJECT_CLASS (_g_dbus_auth_parent_class)->finalize (object);
 122 }
 123
 124 static void
 125 _g_dbus_auth_get_property (GObject    *object,
 126                            guint       prop_id,
 127                            GValue     *value,
 128                            GParamSpec *pspec)
 129 {
 130   GDBusAuth *auth = G_DBUS_AUTH (object);
 131
 132   switch (prop_id)
 133     {
 134     case PROP_STREAM:
 135       g_value_set_object (value, auth->priv->stream);
 136       break;
 137
 138     default:
 139       G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
 140       break;
 141     }
 142 }
 143
 144 static void
 145 _g_dbus_auth_set_property (GObject      *object,
 146                            guint         prop_id,
 147                            const GValue *value,
 148                            GParamSpec   *pspec)
 149 {
 150   GDBusAuth *auth = G_DBUS_AUTH (object);
 151
 152   switch (prop_id)
 153     {
 154     case PROP_STREAM:
 155       auth->priv->stream = g_value_dup_object (value);
 156       break;
 157
 158     default:
 159       G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
 160       break;
 161     }
 162 }
 163
 164 static void
 165 _g_dbus_auth_class_init (GDBusAuthClass *klass)
 166 {
 167   GObjectClass *gobject_class;
 168
 169   g_type_class_add_private (klass, sizeof (GDBusAuthPrivate));
 170
 171   gobject_class = G_OBJECT_CLASS (klass);
 172   gobject_class->get_property = _g_dbus_auth_get_property;
 173   gobject_class->set_property = _g_dbus_auth_set_property;
 174   gobject_class->finalize     = _g_dbus_auth_finalize;
 175
 176   g_object_class_install_property (gobject_class,
 177                                    PROP_STREAM,
 178                                    g_param_spec_object ("stream",
 179                                                         P_("IO Stream"),
 180                                                         P_("The underlying GIOStream used for I/O"),
 181                                                         G_TYPE_IO_STREAM,
 182                                                         G_PARAM_READABLE |
 183                                                         G_PARAM_WRITABLE |
 184                                                         G_PARAM_CONSTRUCT_ONLY |
 185                                                         G_PARAM_STATIC_NAME |
 186                                                         G_PARAM_STATIC_BLURB |
 187                                                         G_PARAM_STATIC_NICK));
 188 }
 189
 190 static void
 191 mechanism_free (Mechanism *m)
 192 {
 193   g_free (m);
 194 }
 195
 196 static void
 197 add_mechanism (GDBusAuth *auth,
 198                GType      mechanism_type)
 199 {
 200   Mechanism *m;
 201
 202   m = g_new0 (Mechanism, 1);
 203   m->name = _g_dbus_auth_mechanism_get_name (mechanism_type);
 204   m->priority = _g_dbus_auth_mechanism_get_priority (mechanism_type);
 205   m->gtype = mechanism_type;
 206
 207   auth->priv->available_mechanisms = g_list_prepend (auth->priv->available_mechanisms, m);
 208 }
 209
 210 static gint
 211 mech_compare_func (Mechanism *a, Mechanism *b)
 212 {
 213   gint ret;
 214   /* ensure deterministic order */
 215   ret = b->priority - a->priority;
 216   if (ret == 0)
 217     ret = g_strcmp0 (b->name, a->name);
 218   return ret;
 219 }
 220
 221 static void
 222 _g_dbus_auth_init (GDBusAuth *auth)
 223 {
 224   auth->priv = G_TYPE_INSTANCE_GET_PRIVATE (auth, G_TYPE_DBUS_AUTH, GDBusAuthPrivate);
 225
 226   /* TODO: trawl extension points */
 227   add_mechanism (auth, G_TYPE_DBUS_AUTH_MECHANISM_ANON);
 228   add_mechanism (auth, G_TYPE_DBUS_AUTH_MECHANISM_SHA1);
 229   add_mechanism (auth, G_TYPE_DBUS_AUTH_MECHANISM_EXTERNAL);
 230
 231   auth->priv->available_mechanisms = g_list_sort (auth->priv->available_mechanisms,
 232                                                   (GCompareFunc) mech_compare_func);
 233 }
 234
 235 static GType
 236 find_mech_by_name (GDBusAuth *auth,
 237                    const gchar *name)
 238 {
 239   GType ret;
 240   GList *l;
 241
 242   ret = (GType) 0;
 243
 244   for (l = auth->priv->available_mechanisms; l != NULL; l = l->next)
 245     {
 246       Mechanism *m = l->data;
 247       if (g_strcmp0 (name, m->name) == 0)
 248         {
 249           ret = m->gtype;
 250           goto out;
 251         }
 252     }
 253
 254  out:
 255   return ret;
 256 }
 257
 258 GDBusAuth  *
 259 _g_dbus_auth_new (GIOStream *stream)
 260 {
 261   return g_object_new (G_TYPE_DBUS_AUTH,
 262                        "stream", stream,
 263                        NULL);
 264 }
 265
 266 /* ---------------------------------------------------------------------------------------------------- */
 267 /* like g_data_input_stream_read_line() but sets error if there's no content to read */
 268 static gchar *
 269 _my_g_data_input_stream_read_line (GDataInputStream  *dis,
 270                                    gsize             *out_line_length,
 271                                    GCancellable      *cancellable,
 272                                    GError           **error)
 273 {
 274   gchar *ret;
 275
 276   g_return_val_if_fail (error == NULL || *error == NULL, NULL);
 277
 278   ret = g_data_input_stream_read_line (dis,
 279                                        out_line_length,
 280                                        cancellable,
 281                                        error);
 282   if (ret == NULL && error != NULL && *error == NULL)
 283     {
 284       g_set_error_literal (error,
 285                            G_IO_ERROR,
 286                            G_IO_ERROR_FAILED,
 287                            _("Unexpected lack of content trying to read a line"));
 288     }
 289
 290   return ret;
 291 }
 292
 293 /* This function is to avoid situations like this
 294  *
 295  * BEGIN\r\nl\0\0\1...
 296  *
 297  * e.g. where we read into the first D-Bus message while waiting for
 298  * the final line from the client (TODO: file bug against gio for
 299  * this)
 300  */
 301 static gchar *
 302 _my_g_input_stream_read_line_safe (GInputStream  *i,
 303                                    gsize         *out_line_length,
 304                                    GCancellable  *cancellable,
 305                                    GError       **error)
 306 {
 307   GString *str;
 308   gchar c;
 309   gssize num_read;
 310   gboolean last_was_cr;
 311
 312   str = g_string_new (NULL);
 313
 314   last_was_cr = FALSE;
 315   while (TRUE)
 316     {
 317       num_read = g_input_stream_read (i,
 318                                       &c,
 319                                       1,
 320                                       cancellable,
 321                                       error);
 322       if (num_read == -1)
 323         goto fail;
 324       if (num_read == 0)
 325         {
 326           if (error != NULL && *error == NULL)
 327             {
 328               g_set_error_literal (error,
 329                                    G_IO_ERROR,
 330                                    G_IO_ERROR_FAILED,
 331                                    _("Unexpected lack of content trying to (safely) read a line"));
 332             }
 333           goto fail;
 334         }
 335
 336       g_string_append_c (str, (gint) c);
 337       if (last_was_cr)
 338         {
 339           if (c == 0x0a)
 340             {
 341               g_assert (str->len >= 2);
 342               g_string_set_size (str, str->len - 2);
 343               goto out;
 344             }
 345         }
 346       last_was_cr = (c == 0x0d);
 347     }
 348
 349  out:
 350   if (out_line_length != NULL)
 351     *out_line_length = str->len;
 352   return g_string_free (str, FALSE);
 353
 354  fail:
 355   g_assert (error == NULL || *error != NULL);
 356   g_string_free (str, TRUE);
 357   return NULL;
 358 }
 359
 360 /* ---------------------------------------------------------------------------------------------------- */
 361
 362 static void
 363 append_nibble (GString *s, gint val)
 364 {
 365   g_string_append_c (s, val >= 10 ? ('a' + val - 10) : ('0' + val));
 366 }
 367
 368 static gchar *
 369 hexdecode (const gchar  *str,
 370            gsize        *out_len,
 371            GError      **error)
 372 {
 373   gchar *ret;
 374   GString *s;
 375   guint n;
 376
 377   ret = NULL;
 378   s = g_string_new (NULL);
 379
 380   for (n = 0; str[n] != '\0'; n += 2)
 381     {
 382       gint upper_nibble;
 383       gint lower_nibble;
 384       guint value;
 385
 386       upper_nibble = g_ascii_xdigit_value (str[n]);
 387       lower_nibble = g_ascii_xdigit_value (str[n + 1]);
 388       if (upper_nibble == -1 || lower_nibble == -1)
 389         {
 390           g_set_error (error,
 391                        G_IO_ERROR,
 392                        G_IO_ERROR_FAILED,
 393                        "Error hexdecoding string `%s' around position %d",
 394                        str, n);
 395           goto out;
 396         }
 397       value = (upper_nibble<<4) | lower_nibble;
 398       g_string_append_c (s, value);
 399     }
 400
 401   ret = g_string_free (s, FALSE);
 402   s = NULL;
 403
 404  out:
 405   if (s != NULL)
 406     g_string_free (s, TRUE);
 407   return ret;
 408 }
 409
 410 /* TODO: take len */
 411 static gchar *
 412 hexencode (const gchar *str)
 413 {
 414   guint n;
 415   GString *s;
 416
 417   s = g_string_new (NULL);
 418   for (n = 0; str[n] != '\0'; n++)
 419     {
 420       gint val;
 421       gint upper_nibble;
 422       gint lower_nibble;
 423
 424       val = ((const guchar *) str)[n];
 425       upper_nibble = val >> 4;
 426       lower_nibble = val & 0x0f;
 427
 428       append_nibble (s, upper_nibble);
 429       append_nibble (s, lower_nibble);
 430     }
 431
 432   return g_string_free (s, FALSE);
 433 }
 434
 435 /* ---------------------------------------------------------------------------------------------------- */
 436
 437 static GDBusAuthMechanism *
 438 client_choose_mech_and_send_initial_response (GDBusAuth           *auth,
 439                                               GCredentials        *credentials_that_were_sent,
 440                                               const gchar* const  *supported_auth_mechs,
 441                                               GPtrArray           *attempted_auth_mechs,
 442                                               GDataOutputStream   *dos,
 443                                               GCancellable        *cancellable,
 444                                               GError             **error)
 445 {
 446   GDBusAuthMechanism *mech;
 447   GType auth_mech_to_use_gtype;
 448   guint n;
 449   guint m;
 450   gchar *initial_response;
 451   gsize initial_response_len;
 452   gchar *encoded;
 453   gchar *s;
 454
 455  again:
 456   mech = NULL;
 457
 458   debug_print ("CLIENT: Trying to choose mechanism");
 459
 460   /* find an authentication mechanism to try, if any */
 461   auth_mech_to_use_gtype = (GType) 0;
 462   for (n = 0; supported_auth_mechs[n] != NULL; n++)
 463     {
 464       gboolean attempted_already;
 465       attempted_already = FALSE;
 466       for (m = 0; m < attempted_auth_mechs->len; m++)
 467         {
 468           if (g_strcmp0 (supported_auth_mechs[n], attempted_auth_mechs->pdata[m]) == 0)
 469             {
 470               attempted_already = TRUE;
 471               break;
 472             }
 473         }
 474       if (!attempted_already)
 475         {
 476           auth_mech_to_use_gtype = find_mech_by_name (auth, supported_auth_mechs[n]);
 477           if (auth_mech_to_use_gtype != (GType) 0)
 478             break;
 479         }
 480     }
 481
 482   if (auth_mech_to_use_gtype == (GType) 0)
 483     {
 484       guint n;
 485       gchar *available;
 486       GString *tried_str;
 487
 488       debug_print ("CLIENT: Exhausted all available mechanisms");
 489
 490       available = g_strjoinv (", ", (gchar **) supported_auth_mechs);
 491
 492       tried_str = g_string_new (NULL);
 493       for (n = 0; n < attempted_auth_mechs->len; n++)
 494         {
 495           if (n > 0)
 496             g_string_append (tried_str, ", ");
 497           g_string_append (tried_str, attempted_auth_mechs->pdata[n]);
 498         }
 499       g_set_error (error,
 500                    G_IO_ERROR,
 501                    G_IO_ERROR_FAILED,
 502                    _("Exhausted all available authentication mechanisms (tried: %s) (available: %s)"),
 503                    tried_str->str,
 504                    available);
 505       g_string_free (tried_str, TRUE);
 506       g_free (available);
 507       goto out;
 508     }
 509
 510   /* OK, decided on a mechanism - let's do this thing */
 511   mech = g_object_new (auth_mech_to_use_gtype,
 512                        "stream", auth->priv->stream,
 513                        "credentials", credentials_that_were_sent,
 514                        NULL);
 515   debug_print ("CLIENT: Trying mechanism `%s'", _g_dbus_auth_mechanism_get_name (auth_mech_to_use_gtype));
 516   g_ptr_array_add (attempted_auth_mechs, (gpointer) _g_dbus_auth_mechanism_get_name (auth_mech_to_use_gtype));
 517
 518   /* the auth mechanism may not be supported
 519    * (for example, EXTERNAL only works if credentials were exchanged)
 520    */
 521   if (!_g_dbus_auth_mechanism_is_supported (mech))
 522     {
 523       debug_print ("CLIENT: Mechanism `%s' says it is not supported", _g_dbus_auth_mechanism_get_name (auth_mech_to_use_gtype));
 524       g_object_unref (mech);
 525       mech = NULL;
 526       goto again;
 527     }
 528
 529   initial_response_len = -1;
 530   initial_response = _g_dbus_auth_mechanism_client_initiate (mech,
 531                                                              &initial_response_len);
 532 #if 0
 533   g_printerr ("using auth mechanism with name `%s' of type `%s' with initial response `%s'\n",
 534               _g_dbus_auth_mechanism_get_name (auth_mech_to_use_gtype),
 535               g_type_name (G_TYPE_FROM_INSTANCE (mech)),
 536               initial_response);
 537 #endif
 538   if (initial_response != NULL)
 539     {
 540       //g_printerr ("initial_response = `%s'\n", initial_response);
 541       encoded = hexencode (initial_response);
 542       s = g_strdup_printf ("AUTH %s %s\r\n",
 543                            _g_dbus_auth_mechanism_get_name (auth_mech_to_use_gtype),
 544                            encoded);
 545       g_free (initial_response);
 546       g_free (encoded);
 547     }
 548   else
 549     {
 550       s = g_strdup_printf ("AUTH %s\r\n", _g_dbus_auth_mechanism_get_name (auth_mech_to_use_gtype));
 551     }
 552   debug_print ("CLIENT: writing `%s'", s);
 553   if (!g_data_output_stream_put_string (dos, s, cancellable, error))
 554     {
 555       g_object_unref (mech);
 556       mech = NULL;
 557       g_free (s);
 558       goto out;
 559     }
 560   g_free (s);
 561
 562  out:
 563   return mech;
 564 }
 565
 566
 567 /* ---------------------------------------------------------------------------------------------------- */
 568
 569 typedef enum
 570 {
 571   CLIENT_STATE_WAITING_FOR_DATA,
 572   CLIENT_STATE_WAITING_FOR_OK,
 573   CLIENT_STATE_WAITING_FOR_REJECT,
 574   CLIENT_STATE_WAITING_FOR_AGREE_UNIX_FD
 575 } ClientState;
 576
 577 gchar *
 578 _g_dbus_auth_run_client (GDBusAuth     *auth,
 579                          GDBusCapabilityFlags offered_capabilities,
 580                          GDBusCapabilityFlags *out_negotiated_capabilities,
 581                          GCancellable  *cancellable,
 582                          GError       **error)
 583 {
 584   gchar *s;
 585   GDataInputStream *dis;
 586   GDataOutputStream *dos;
 587   GCredentials *credentials;
 588   gchar *ret_guid;
 589   gchar *line;
 590   gsize line_length;
 591   gchar **supported_auth_mechs;
 592   GPtrArray *attempted_auth_mechs;
 593   GDBusAuthMechanism *mech;
 594   ClientState state;
 595   GDBusCapabilityFlags negotiated_capabilities;
 596
 597   debug_print ("CLIENT: initiating");
 598
 599   ret_guid = NULL;
 600   supported_auth_mechs = NULL;
 601   attempted_auth_mechs = g_ptr_array_new ();
 602   mech = NULL;
 603   negotiated_capabilities = 0;
 604   credentials = NULL;
 605
 606   dis = G_DATA_INPUT_STREAM (g_data_input_stream_new (g_io_stream_get_input_stream (auth->priv->stream)));
 607   dos = G_DATA_OUTPUT_STREAM (g_data_output_stream_new (g_io_stream_get_output_stream (auth->priv->stream)));
 608   g_filter_input_stream_set_close_base_stream (G_FILTER_INPUT_STREAM (dis), FALSE);
 609   g_filter_output_stream_set_close_base_stream (G_FILTER_OUTPUT_STREAM (dos), FALSE);
 610
 611   g_data_input_stream_set_newline_type (dis, G_DATA_STREAM_NEWLINE_TYPE_CR_LF);
 612
 613 #ifdef G_OS_UNIX
 614   if (G_IS_UNIX_CONNECTION (auth->priv->stream))
 615     {
 616       credentials = g_credentials_new ();
 617       if (!g_unix_connection_send_credentials (G_UNIX_CONNECTION (auth->priv->stream),
 618                                                cancellable,
 619                                                error))
 620         goto out;
 621     }
 622   else
 623     {
 624       if (!g_data_output_stream_put_byte (dos, '\0', cancellable, error))
 625         goto out;
 626     }
 627 #else
 628   if (!g_data_output_stream_put_byte (dos, '\0', cancellable, error))
 629     goto out;
 630 #endif
 631
 632   if (credentials != NULL)
 633     {
 634       if (G_UNLIKELY (_g_dbus_debug_authentication ()))
 635         {
 636           s = g_credentials_to_string (credentials);
 637           debug_print ("CLIENT: sent credentials `%s'", s);
 638           g_free (s);
 639         }
 640     }
 641   else
 642     {
 643       debug_print ("CLIENT: didn't send any credentials");
 644     }
 645
 646   /* TODO: to reduce roundtrips, try to pick an auth mechanism to start with */
 647
 648   /* Get list of supported authentication mechanisms */
 649   s = "AUTH\r\n";
 650   debug_print ("CLIENT: writing `%s'", s);
 651   if (!g_data_output_stream_put_string (dos, s, cancellable, error))
 652     goto out;
 653   state = CLIENT_STATE_WAITING_FOR_REJECT;
 654
 655   while (TRUE)
 656     {
 657       switch (state)
 658         {
 659         case CLIENT_STATE_WAITING_FOR_REJECT:
 660           debug_print ("CLIENT: WaitingForReject");
 661           line = _my_g_data_input_stream_read_line (dis, &line_length, cancellable, error);
 662           if (line == NULL)
 663             goto out;
 664           debug_print ("CLIENT: WaitingForReject, read '%s'", line);
 665
 666         choose_mechanism:
 667           if (!g_str_has_prefix (line, "REJECTED "))
 668             {
 669               g_set_error (error,
 670                            G_IO_ERROR,
 671                            G_IO_ERROR_FAILED,
 672                            "In WaitingForReject: Expected `REJECTED am1 am2 ... amN', got `%s'",
 673                            line);
 674               g_free (line);
 675               goto out;
 676             }
 677           if (supported_auth_mechs == NULL)
 678             {
 679               supported_auth_mechs = g_strsplit (line + sizeof ("REJECTED ") - 1, " ", 0);
 680 #if 0
 681               for (n = 0; supported_auth_mechs != NULL && supported_auth_mechs[n] != NULL; n++)
 682                 g_printerr ("supported_auth_mechs[%d] = `%s'\n", n, supported_auth_mechs[n]);
 683 #endif
 684             }
 685           g_free (line);
 686           mech = client_choose_mech_and_send_initial_response (auth,
 687                                                                credentials,
 688                                                                (const gchar* const *) supported_auth_mechs,
 689                                                                attempted_auth_mechs,
 690                                                                dos,
 691                                                                cancellable,
 692                                                                error);
 693           if (mech == NULL)
 694             goto out;
 695           if (_g_dbus_auth_mechanism_client_get_state (mech) == G_DBUS_AUTH_MECHANISM_STATE_WAITING_FOR_DATA)
 696             state = CLIENT_STATE_WAITING_FOR_DATA;
 697           else
 698             state = CLIENT_STATE_WAITING_FOR_OK;
 699           break;
 700
 701         case CLIENT_STATE_WAITING_FOR_OK:
 702           debug_print ("CLIENT: WaitingForOK");
 703           line = _my_g_data_input_stream_read_line (dis, &line_length, cancellable, error);
 704           if (line == NULL)
 705             goto out;
 706           debug_print ("CLIENT: WaitingForOK, read `%s'", line);
 707           if (g_str_has_prefix (line, "OK "))
 708             {
 709               if (!g_dbus_is_guid (line + 3))
 710                 {
 711                   g_set_error (error,
 712                                G_IO_ERROR,
 713                                G_IO_ERROR_FAILED,
 714                                "Invalid OK response `%s'",
 715                                line);
 716                   g_free (line);
 717                   goto out;
 718                 }
 719               ret_guid = g_strdup (line + 3);
 720               g_free (line);
 721
 722               if (offered_capabilities & G_DBUS_CAPABILITY_FLAGS_UNIX_FD_PASSING)
 723                 {
 724                   s = "NEGOTIATE_UNIX_FD\r\n";
 725                   debug_print ("CLIENT: writing `%s'", s);
 726                   if (!g_data_output_stream_put_string (dos, s, cancellable, error))
 727                     goto out;
 728                   state = CLIENT_STATE_WAITING_FOR_AGREE_UNIX_FD;
 729                 }
 730               else
 731                 {
 732                   s = "BEGIN\r\n";
 733                   debug_print ("CLIENT: writing `%s'", s);
 734                   if (!g_data_output_stream_put_string (dos, s, cancellable, error))
 735                     goto out;
 736                   /* and we're done! */
 737                   goto out;
 738                 }
 739             }
 740           else if (g_str_has_prefix (line, "REJECTED "))
 741             {
 742               goto choose_mechanism;
 743             }
 744           else
 745             {
 746               /* TODO: handle other valid responses */
 747               g_set_error (error,
 748                            G_IO_ERROR,
 749                            G_IO_ERROR_FAILED,
 750                            "In WaitingForOk: unexpected response `%s'",
 751                            line);
 752               g_free (line);
 753               goto out;
 754             }
 755           break;
 756
 757         case CLIENT_STATE_WAITING_FOR_AGREE_UNIX_FD:
 758           debug_print ("CLIENT: WaitingForAgreeUnixFD");
 759           line = _my_g_data_input_stream_read_line (dis, &line_length, cancellable, error);
 760           if (line == NULL)
 761             goto out;
 762           debug_print ("CLIENT: WaitingForAgreeUnixFD, read=`%s'", line);
 763           if (g_strcmp0 (line, "AGREE_UNIX_FD") == 0)
 764             {
 765               g_free (line);
 766               negotiated_capabilities |= G_DBUS_CAPABILITY_FLAGS_UNIX_FD_PASSING;
 767               s = "BEGIN\r\n";
 768               debug_print ("CLIENT: writing `%s'", s);
 769               if (!g_data_output_stream_put_string (dos, s, cancellable, error))
 770                 goto out;
 771               /* and we're done! */
 772               goto out;
 773             }
 774           else if (g_str_has_prefix (line, "ERROR") && (line[5] == 0 || g_ascii_isspace (line[5])))
 775             {
 776               //g_strstrip (line + 5); g_debug ("bah, no unix_fd: `%s'", line + 5);
 777               g_free (line);
 778               s = "BEGIN\r\n";
 779               debug_print ("CLIENT: writing `%s'", s);
 780               if (!g_data_output_stream_put_string (dos, s, cancellable, error))
 781                 goto out;
 782               /* and we're done! */
 783               goto out;
 784             }
 785           else
 786             {
 787               /* TODO: handle other valid responses */
 788               g_set_error (error,
 789                            G_IO_ERROR,
 790                            G_IO_ERROR_FAILED,
 791                            "In WaitingForAgreeUnixFd: unexpected response `%s'",
 792                            line);
 793               g_free (line);
 794               goto out;
 795             }
 796           break;
 797
 798         case CLIENT_STATE_WAITING_FOR_DATA:
 799           debug_print ("CLIENT: WaitingForData");
 800           line = _my_g_data_input_stream_read_line (dis, &line_length, cancellable, error);
 801           if (line == NULL)
 802             goto out;
 803           debug_print ("CLIENT: WaitingForData, read=`%s'", line);
 804           if (g_str_has_prefix (line, "DATA "))
 805             {
 806               gchar *encoded;
 807               gchar *decoded_data;
 808               gsize decoded_data_len = 0;
 809
 810               encoded = g_strdup (line + 5);
 811               g_free (line);
 812               g_strstrip (encoded);
 813               decoded_data = hexdecode (encoded, &decoded_data_len, error);
 814               g_free (encoded);
 815               if (decoded_data == NULL)
 816                 {
 817                   g_prefix_error (error, "DATA response is malformed: ");
 818                   /* invalid encoding, disconnect! */
 819                   goto out;
 820                 }
 821               _g_dbus_auth_mechanism_client_data_receive (mech, decoded_data, decoded_data_len);
 822               g_free (decoded_data);
 823
 824               if (_g_dbus_auth_mechanism_client_get_state (mech) == G_DBUS_AUTH_MECHANISM_STATE_HAVE_DATA_TO_SEND)
 825                 {
 826                   gchar *data;
 827                   gsize data_len;
 828                   gchar *encoded_data;
 829                   data = _g_dbus_auth_mechanism_client_data_send (mech, &data_len);
 830                   encoded_data = hexencode (data);
 831                   s = g_strdup_printf ("DATA %s\r\n", encoded_data);
 832                   g_free (encoded_data);
 833                   g_free (data);
 834                   debug_print ("CLIENT: writing `%s'", s);
 835                   if (!g_data_output_stream_put_string (dos, s, cancellable, error))
 836                     {
 837                       g_free (s);
 838                       goto out;
 839                     }
 840                   g_free (s);
 841                 }
 842               state = CLIENT_STATE_WAITING_FOR_OK;
 843             }
 844           else if (g_str_has_prefix (line, "REJECTED "))
 845             {
 846               /* could be the chosen authentication method just doesn't work. Try
 847                * another one...
 848                */
 849               goto choose_mechanism;
 850             }
 851           else
 852             {
 853               g_set_error (error,
 854                            G_IO_ERROR,
 855                            G_IO_ERROR_FAILED,
 856                            "In WaitingForData: unexpected response `%s'",
 857                            line);
 858               g_free (line);
 859               goto out;
 860             }
 861           break;
 862
 863         default:
 864           g_assert_not_reached ();
 865           break;
 866         }
 867
 868     }; /* main authentication client loop */
 869
 870  out:
 871   if (mech != NULL)
 872     g_object_unref (mech);
 873   g_ptr_array_unref (attempted_auth_mechs);
 874   g_strfreev (supported_auth_mechs);
 875   g_object_unref (dis);
 876   g_object_unref (dos);
 877
 878   /* ensure return value is NULL if error is set */
 879   if (error != NULL && *error != NULL)
 880     {
 881       g_free (ret_guid);
 882       ret_guid = NULL;
 883     }
 884
 885   if (ret_guid != NULL)
 886     {
 887       if (out_negotiated_capabilities != NULL)
 888         *out_negotiated_capabilities = negotiated_capabilities;
 889     }
 890
 891   if (credentials != NULL)
 892     g_object_unref (credentials);
 893
 894   debug_print ("CLIENT: Done, authenticated=%d", ret_guid != NULL);
 895
 896   return ret_guid;
 897 }
 898
 899 /* ---------------------------------------------------------------------------------------------------- */
 900
 901 static gchar *
 902 get_auth_mechanisms (GDBusAuth     *auth,
 903                      gboolean       allow_anonymous,
 904                      const gchar   *prefix,
 905                      const gchar   *suffix,
 906                      const gchar   *separator)
 907 {
 908   GList *l;
 909   GString *str;
 910   gboolean need_sep;
 911
 912   str = g_string_new (prefix);
 913   need_sep = FALSE;
 914   for (l = auth->priv->available_mechanisms; l != NULL; l = l->next)
 915     {
 916       Mechanism *m = l->data;
 917
 918       if (!allow_anonymous && g_strcmp0 (m->name, "ANONYMOUS") == 0)
 919         continue;
 920
 921       if (need_sep)
 922         g_string_append (str, separator);
 923       g_string_append (str, m->name);
 924       need_sep = TRUE;
 925     }
 926
 927   g_string_append (str, suffix);
 928   return g_string_free (str, FALSE);
 929 }
 930
 931
 932 typedef enum
 933 {
 934   SERVER_STATE_WAITING_FOR_AUTH,
 935   SERVER_STATE_WAITING_FOR_DATA,
 936   SERVER_STATE_WAITING_FOR_BEGIN
 937 } ServerState;
 938
 939 gboolean
 940 _g_dbus_auth_run_server (GDBusAuth              *auth,
 941                          GDBusAuthObserver      *observer,
 942                          const gchar            *guid,
 943                          gboolean                allow_anonymous,
 944                          GDBusCapabilityFlags    offered_capabilities,
 945                          GDBusCapabilityFlags   *out_negotiated_capabilities,
 946                          GCredentials          **out_received_credentials,
 947                          GCancellable           *cancellable,
 948                          GError                **error)
 949 {
 950   gboolean ret;
 951   ServerState state;
 952   GDataInputStream *dis;
 953   GDataOutputStream *dos;
 954   GError *local_error;
 955   guchar byte;
 956   gchar *line;
 957   gsize line_length;
 958   GDBusAuthMechanism *mech;
 959   gchar *s;
 960   GDBusCapabilityFlags negotiated_capabilities;
 961   GCredentials *credentials;
 962
 963   debug_print ("SERVER: initiating");
 964
 965   ret = FALSE;
 966   dis = NULL;
 967   dos = NULL;
 968   mech = NULL;
 969   negotiated_capabilities = 0;
 970   credentials = NULL;
 971
 972   if (!g_dbus_is_guid (guid))
 973     {
 974       g_set_error (error,
 975                    G_IO_ERROR,
 976                    G_IO_ERROR_FAILED,
 977                    "The given guid `%s' is not valid",
 978                    guid);
 979       goto out;
 980     }
 981
 982   dis = G_DATA_INPUT_STREAM (g_data_input_stream_new (g_io_stream_get_input_stream (auth->priv->stream)));
 983   dos = G_DATA_OUTPUT_STREAM (g_data_output_stream_new (g_io_stream_get_output_stream (auth->priv->stream)));
 984   g_filter_input_stream_set_close_base_stream (G_FILTER_INPUT_STREAM (dis), FALSE);
 985   g_filter_output_stream_set_close_base_stream (G_FILTER_OUTPUT_STREAM (dos), FALSE);
 986
 987   g_data_input_stream_set_newline_type (dis, G_DATA_STREAM_NEWLINE_TYPE_CR_LF);
 988
 989   /* first read the NUL-byte (TODO: read credentials if using a unix domain socket) */
 990 #ifdef G_OS_UNIX
 991   if (G_IS_UNIX_CONNECTION (auth->priv->stream))
 992     {
 993       local_error = NULL;
 994       credentials = g_unix_connection_receive_credentials (G_UNIX_CONNECTION (auth->priv->stream),
 995                                                            cancellable,
 996                                                            &local_error);
 997       if (credentials == NULL && !g_error_matches (local_error, G_IO_ERROR, G_IO_ERROR_NOT_SUPPORTED))
 998         {
 999           g_propagate_error (error, local_error);
1000           goto out;
1001         }
1002     }
1003   else
1004     {
1005       local_error = NULL;
1006       byte = g_data_input_stream_read_byte (dis, cancellable, &local_error);
1007       byte = byte; /* To avoid -Wunused-but-set-variable */
1008       if (local_error != NULL)
1009         {
1010           g_propagate_error (error, local_error);
1011           goto out;
1012         }
1013     }
1014 #else
1015   local_error = NULL;
1016   byte = g_data_input_stream_read_byte (dis, cancellable, &local_error);
1017   if (local_error != NULL)
1018     {
1019       g_propagate_error (error, local_error);
1020       goto out;
1021     }
1022 #endif
1023   if (credentials != NULL)
1024     {
1025       if (G_UNLIKELY (_g_dbus_debug_authentication ()))
1026         {
1027           s = g_credentials_to_string (credentials);
1028           debug_print ("SERVER: received credentials `%s'", s);
1029           g_free (s);
1030         }
1031     }
1032   else
1033     {
1034       debug_print ("SERVER: didn't receive any credentials");
1035     }
1036
1037   state = SERVER_STATE_WAITING_FOR_AUTH;
1038   while (TRUE)
1039     {
1040       switch (state)
1041         {
1042         case SERVER_STATE_WAITING_FOR_AUTH:
1043           debug_print ("SERVER: WaitingForAuth");
1044           line = _my_g_data_input_stream_read_line (dis, &line_length, cancellable, error);
1045           debug_print ("SERVER: WaitingForAuth, read `%s'", line);
1046           if (line == NULL)
1047             goto out;
1048           if (g_strcmp0 (line, "AUTH") == 0)
1049             {
1050               s = get_auth_mechanisms (auth, allow_anonymous, "REJECTED ", "\r\n", " ");
1051               debug_print ("SERVER: writing `%s'", s);
1052               if (!g_data_output_stream_put_string (dos, s, cancellable, error))
1053                 {
1054                   g_free (s);
1055                   goto out;
1056                 }
1057               g_free (s);
1058               g_free (line);
1059             }
1060           else if (g_str_has_prefix (line, "AUTH "))
1061             {
1062               gchar **tokens;
1063               const gchar *encoded;
1064               const gchar *mech_name;
1065               GType auth_mech_to_use_gtype;
1066
1067               tokens = g_strsplit (line, " ", 0);
1068               g_free (line);
1069
1070               switch (g_strv_length (tokens))
1071                 {
1072                 case 2:
1073                   /* no initial response */
1074                   mech_name = tokens[1];
1075                   encoded = NULL;
1076                   break;
1077
1078                 case 3:
1079                   /* initial response */
1080                   mech_name = tokens[1];
1081                   encoded = tokens[2];
1082                   break;
1083
1084                 default:
1085                   g_set_error (error,
1086                                G_IO_ERROR,
1087                                G_IO_ERROR_FAILED,
1088                                "Unexpected line `%s' while in WaitingForAuth state",
1089                                line);
1090                   g_strfreev (tokens);
1091                   goto out;
1092                 }
1093
1094               /* TODO: record that the client has attempted to use this mechanism */
1095               //g_debug ("client is trying `%s'", mech_name);
1096
1097               auth_mech_to_use_gtype = find_mech_by_name (auth, mech_name);
1098               if ((auth_mech_to_use_gtype == (GType) 0) ||
1099                   (!allow_anonymous && g_strcmp0 (mech_name, "ANONYMOUS") == 0))
1100                 {
1101                   /* We don't support this auth mechanism */
1102                   g_strfreev (tokens);
1103                   s = get_auth_mechanisms (auth, allow_anonymous, "REJECTED ", "\r\n", " ");
1104                   debug_print ("SERVER: writing `%s'", s);
1105                   if (!g_data_output_stream_put_string (dos, s, cancellable, error))
1106                     {
1107                       g_free (s);
1108                       goto out;
1109                     }
1110                   g_free (s);
1111
1112                   /* stay in WAITING FOR AUTH */
1113                   state = SERVER_STATE_WAITING_FOR_AUTH;
1114                 }
1115               else
1116                 {
1117                   gchar *initial_response;
1118                   gsize initial_response_len;
1119
1120                   mech = g_object_new (auth_mech_to_use_gtype,
1121                                        "stream", auth->priv->stream,
1122                                        "credentials", credentials,
1123                                        NULL);
1124
1125                   initial_response = NULL;
1126                   initial_response_len = 0;
1127                   if (encoded != NULL)
1128                     {
1129                       initial_response = hexdecode (encoded, &initial_response_len, error);
1130                       if (initial_response == NULL)
1131                         {
1132                           g_prefix_error (error, "Initial response is malformed: ");
1133                           /* invalid encoding, disconnect! */
1134                           g_strfreev (tokens);
1135                           goto out;
1136                         }
1137                     }
1138
1139                   _g_dbus_auth_mechanism_server_initiate (mech,
1140                                                           initial_response,
1141                                                           initial_response_len);
1142                   g_free (initial_response);
1143                   g_strfreev (tokens);
1144
1145                 change_state:
1146                   switch (_g_dbus_auth_mechanism_server_get_state (mech))
1147                     {
1148                     case G_DBUS_AUTH_MECHANISM_STATE_ACCEPTED:
1149                       if (observer != NULL &&
1150                           !g_dbus_auth_observer_authorize_authenticated_peer (observer,
1151                                                                               auth->priv->stream,
1152                                                                               credentials))
1153                         {
1154                           /* disconnect */
1155                           g_set_error_literal (error,
1156                                                G_IO_ERROR,
1157                                                G_IO_ERROR_FAILED,
1158                                                _("Cancelled via GDBusAuthObserver::authorize-authenticated-peer"));
1159                           goto out;
1160                         }
1161                       else
1162                         {
1163                           s = g_strdup_printf ("OK %s\r\n", guid);
1164                           debug_print ("SERVER: writing `%s'", s);
1165                           if (!g_data_output_stream_put_string (dos, s, cancellable, error))
1166                             {
1167                               g_free (s);
1168                               goto out;
1169                             }
1170                           g_free (s);
1171                           state = SERVER_STATE_WAITING_FOR_BEGIN;
1172                         }
1173                       break;
1174
1175                     case G_DBUS_AUTH_MECHANISM_STATE_REJECTED:
1176                       s = get_auth_mechanisms (auth, allow_anonymous, "REJECTED ", "\r\n", " ");
1177                       debug_print ("SERVER: writing `%s'", s);
1178                       if (!g_data_output_stream_put_string (dos, s, cancellable, error))
1179                         {
1180                           g_free (s);
1181                           goto out;
1182                         }
1183                       g_free (s);
1184                       state = SERVER_STATE_WAITING_FOR_AUTH;
1185                       break;
1186
1187                     case G_DBUS_AUTH_MECHANISM_STATE_WAITING_FOR_DATA:
1188                       state = SERVER_STATE_WAITING_FOR_DATA;
1189                       break;
1190
1191                     case G_DBUS_AUTH_MECHANISM_STATE_HAVE_DATA_TO_SEND:
1192                       {
1193                         gchar *data;
1194                         gsize data_len;
1195                         gchar *encoded_data;
1196                         data = _g_dbus_auth_mechanism_server_data_send (mech, &data_len);
1197                         encoded_data = hexencode (data);
1198                         s = g_strdup_printf ("DATA %s\r\n", encoded_data);
1199                         g_free (encoded_data);
1200                         g_free (data);
1201                         debug_print ("SERVER: writing `%s'", s);
1202                         if (!g_data_output_stream_put_string (dos, s, cancellable, error))
1203                           {
1204                             g_free (s);
1205                             goto out;
1206                           }
1207                         g_free (s);
1208                       }
1209                       goto change_state;
1210                       break;
1211
1212                     default:
1213                       /* TODO */
1214                       g_assert_not_reached ();
1215                       break;
1216                     }
1217                 }
1218             }
1219           else
1220             {
1221               g_set_error (error,
1222                            G_IO_ERROR,
1223                            G_IO_ERROR_FAILED,
1224                            "Unexpected line `%s' while in WaitingForAuth state",
1225                            line);
1226               g_free (line);
1227               goto out;
1228             }
1229           break;
1230
1231         case SERVER_STATE_WAITING_FOR_DATA:
1232           debug_print ("SERVER: WaitingForData");
1233           line = _my_g_data_input_stream_read_line (dis, &line_length, cancellable, error);
1234           debug_print ("SERVER: WaitingForData, read `%s'", line);
1235           if (line == NULL)
1236             goto out;
1237           if (g_str_has_prefix (line, "DATA "))
1238             {
1239               gchar *encoded;
1240               gchar *decoded_data;
1241               gsize decoded_data_len = 0;
1242
1243               encoded = g_strdup (line + 5);
1244               g_free (line);
1245               g_strstrip (encoded);
1246               decoded_data = hexdecode (encoded, &decoded_data_len, error);
1247               g_free (encoded);
1248               if (decoded_data == NULL)
1249                 {
1250                   g_prefix_error (error, "DATA response is malformed: ");
1251                   /* invalid encoding, disconnect! */
1252                   goto out;
1253                 }
1254               _g_dbus_auth_mechanism_server_data_receive (mech, decoded_data, decoded_data_len);
1255               g_free (decoded_data);
1256               /* oh man, this goto-crap is so ugly.. really need to rewrite the state machine */
1257               goto change_state;
1258             }
1259           else
1260             {
1261               g_set_error (error,
1262                            G_IO_ERROR,
1263                            G_IO_ERROR_FAILED,
1264                            "Unexpected line `%s' while in WaitingForData state",
1265                            line);
1266               g_free (line);
1267             }
1268           goto out;
1269
1270         case SERVER_STATE_WAITING_FOR_BEGIN:
1271           debug_print ("SERVER: WaitingForBegin");
1272           /* Use extremely slow (but reliable) line reader - this basically
1273            * does a recvfrom() system call per character
1274            *
1275            * (the problem with using GDataInputStream's read_line is that because of
1276            * buffering it might start reading into the first D-Bus message that
1277            * appears after "BEGIN\r\n"....)
1278            */
1279           line = _my_g_input_stream_read_line_safe (g_io_stream_get_input_stream (auth->priv->stream),
1280                                                     &line_length,
1281                                                     cancellable,
1282                                                     error);
1283           debug_print ("SERVER: WaitingForBegin, read `%s'", line);
1284           if (line == NULL)
1285             goto out;
1286           if (g_strcmp0 (line, "BEGIN") == 0)
1287             {
1288               /* YAY, done! */
1289               ret = TRUE;
1290               g_free (line);
1291               goto out;
1292             }
1293           else if (g_strcmp0 (line, "NEGOTIATE_UNIX_FD") == 0)
1294             {
1295               g_free (line);
1296               if (offered_capabilities & G_DBUS_CAPABILITY_FLAGS_UNIX_FD_PASSING)
1297                 {
1298                   negotiated_capabilities |= G_DBUS_CAPABILITY_FLAGS_UNIX_FD_PASSING;
1299                   s = "AGREE_UNIX_FD\r\n";
1300                   debug_print ("SERVER: writing `%s'", s);
1301                   if (!g_data_output_stream_put_string (dos, s, cancellable, error))
1302                     goto out;
1303                 }
1304               else
1305                 {
1306                   s = "ERROR \"fd passing not offered\"\r\n";
1307                   debug_print ("SERVER: writing `%s'", s);
1308                   if (!g_data_output_stream_put_string (dos, s, cancellable, error))
1309                     goto out;
1310                 }
1311             }
1312           else
1313             {
1314               g_debug ("Unexpected line `%s' while in WaitingForBegin state", line);
1315               g_free (line);
1316               s = "ERROR \"Unknown Command\"\r\n";
1317               debug_print ("SERVER: writing `%s'", s);
1318               if (!g_data_output_stream_put_string (dos, s, cancellable, error))
1319                 goto out;
1320             }
1321           break;
1322
1323         default:
1324           g_assert_not_reached ();
1325           break;
1326         }
1327     }
1328
1329
1330   g_set_error_literal (error,
1331                        G_IO_ERROR,
1332                        G_IO_ERROR_FAILED,
1333                        "Not implemented (server)");
1334
1335  out:
1336   if (mech != NULL)
1337     g_object_unref (mech);
1338   if (dis != NULL)
1339     g_object_unref (dis);
1340   if (dos != NULL)
1341     g_object_unref (dos);
1342
1343   /* ensure return value is FALSE if error is set */
1344   if (error != NULL && *error != NULL)
1345     {
1346       ret = FALSE;
1347     }
1348
1349   if (ret)
1350     {
1351       if (out_negotiated_capabilities != NULL)
1352         *out_negotiated_capabilities = negotiated_capabilities;
1353       if (out_received_credentials != NULL)
1354         *out_received_credentials = credentials != NULL ? g_object_ref (credentials) : NULL;
1355     }
1356
1357   if (credentials != NULL)
1358     g_object_unref (credentials);
1359
1360   debug_print ("SERVER: Done, authenticated=%d", ret);
1361
1362   return ret;
1363 }
1364
1365 /* ---------------------------------------------------------------------------------------------------- */