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                GDBusAuthObserver *observer,
 199                GType              mechanism_type)
 200 {
 201   const gchar *name;
 202
 203   name = _g_dbus_auth_mechanism_get_name (mechanism_type);
 204   if (observer == NULL || g_dbus_auth_observer_allow_mechanism (observer, name))
 205     {
 206       Mechanism *m;
 207       m = g_new0 (Mechanism, 1);
 208       m->name = name;
 209       m->priority = _g_dbus_auth_mechanism_get_priority (mechanism_type);
 210       m->gtype = mechanism_type;
 211       auth->priv->available_mechanisms = g_list_prepend (auth->priv->available_mechanisms, m);
 212     }
 213 }
 214
 215 static gint
 216 mech_compare_func (Mechanism *a, Mechanism *b)
 217 {
 218   gint ret;
 219   /* ensure deterministic order */
 220   ret = b->priority - a->priority;
 221   if (ret == 0)
 222     ret = g_strcmp0 (b->name, a->name);
 223   return ret;
 224 }
 225
 226 static void
 227 _g_dbus_auth_init (GDBusAuth *auth)
 228 {
 229   auth->priv = G_TYPE_INSTANCE_GET_PRIVATE (auth, G_TYPE_DBUS_AUTH, GDBusAuthPrivate);
 230
 231 }
 232
 233 static void
 234 _g_dbus_auth_add_mechs (GDBusAuth         *auth,
 235                         GDBusAuthObserver *observer)
 236 {
 237   /* TODO: trawl extension points */
 238   add_mechanism (auth, observer, G_TYPE_DBUS_AUTH_MECHANISM_ANON);
 239   add_mechanism (auth, observer, G_TYPE_DBUS_AUTH_MECHANISM_SHA1);
 240   add_mechanism (auth, observer, G_TYPE_DBUS_AUTH_MECHANISM_EXTERNAL);
 241
 242   auth->priv->available_mechanisms = g_list_sort (auth->priv->available_mechanisms,
 243                                                   (GCompareFunc) mech_compare_func);
 244 }
 245
 246 static GType
 247 find_mech_by_name (GDBusAuth *auth,
 248                    const gchar *name)
 249 {
 250   GType ret;
 251   GList *l;
 252
 253   ret = (GType) 0;
 254
 255   for (l = auth->priv->available_mechanisms; l != NULL; l = l->next)
 256     {
 257       Mechanism *m = l->data;
 258       if (g_strcmp0 (name, m->name) == 0)
 259         {
 260           ret = m->gtype;
 261           goto out;
 262         }
 263     }
 264
 265  out:
 266   return ret;
 267 }
 268
 269 GDBusAuth  *
 270 _g_dbus_auth_new (GIOStream *stream)
 271 {
 272   return g_object_new (G_TYPE_DBUS_AUTH,
 273                        "stream", stream,
 274                        NULL);
 275 }
 276
 277 /* ---------------------------------------------------------------------------------------------------- */
 278 /* like g_data_input_stream_read_line() but sets error if there's no content to read */
 279 static gchar *
 280 _my_g_data_input_stream_read_line (GDataInputStream  *dis,
 281                                    gsize             *out_line_length,
 282                                    GCancellable      *cancellable,
 283                                    GError           **error)
 284 {
 285   gchar *ret;
 286
 287   g_return_val_if_fail (error == NULL || *error == NULL, NULL);
 288
 289   ret = g_data_input_stream_read_line (dis,
 290                                        out_line_length,
 291                                        cancellable,
 292                                        error);
 293   if (ret == NULL && error != NULL && *error == NULL)
 294     {
 295       g_set_error_literal (error,
 296                            G_IO_ERROR,
 297                            G_IO_ERROR_FAILED,
 298                            _("Unexpected lack of content trying to read a line"));
 299     }
 300
 301   return ret;
 302 }
 303
 304 /* This function is to avoid situations like this
 305  *
 306  * BEGIN\r\nl\0\0\1...
 307  *
 308  * e.g. where we read into the first D-Bus message while waiting for
 309  * the final line from the client (TODO: file bug against gio for
 310  * this)
 311  */
 312 static gchar *
 313 _my_g_input_stream_read_line_safe (GInputStream  *i,
 314                                    gsize         *out_line_length,
 315                                    GCancellable  *cancellable,
 316                                    GError       **error)
 317 {
 318   GString *str;
 319   gchar c;
 320   gssize num_read;
 321   gboolean last_was_cr;
 322
 323   str = g_string_new (NULL);
 324
 325   last_was_cr = FALSE;
 326   while (TRUE)
 327     {
 328       num_read = g_input_stream_read (i,
 329                                       &c,
 330                                       1,
 331                                       cancellable,
 332                                       error);
 333       if (num_read == -1)
 334         goto fail;
 335       if (num_read == 0)
 336         {
 337           if (error != NULL && *error == NULL)
 338             {
 339               g_set_error_literal (error,
 340                                    G_IO_ERROR,
 341                                    G_IO_ERROR_FAILED,
 342                                    _("Unexpected lack of content trying to (safely) read a line"));
 343             }
 344           goto fail;
 345         }
 346
 347       g_string_append_c (str, (gint) c);
 348       if (last_was_cr)
 349         {
 350           if (c == 0x0a)
 351             {
 352               g_assert (str->len >= 2);
 353               g_string_set_size (str, str->len - 2);
 354               goto out;
 355             }
 356         }
 357       last_was_cr = (c == 0x0d);
 358     }
 359
 360  out:
 361   if (out_line_length != NULL)
 362     *out_line_length = str->len;
 363   return g_string_free (str, FALSE);
 364
 365  fail:
 366   g_assert (error == NULL || *error != NULL);
 367   g_string_free (str, TRUE);
 368   return NULL;
 369 }
 370
 371 /* ---------------------------------------------------------------------------------------------------- */
 372
 373 static void
 374 append_nibble (GString *s, gint val)
 375 {
 376   g_string_append_c (s, val >= 10 ? ('a' + val - 10) : ('0' + val));
 377 }
 378
 379 static gchar *
 380 hexdecode (const gchar  *str,
 381            gsize        *out_len,
 382            GError      **error)
 383 {
 384   gchar *ret;
 385   GString *s;
 386   guint n;
 387
 388   ret = NULL;
 389   s = g_string_new (NULL);
 390
 391   for (n = 0; str[n] != '\0'; n += 2)
 392     {
 393       gint upper_nibble;
 394       gint lower_nibble;
 395       guint value;
 396
 397       upper_nibble = g_ascii_xdigit_value (str[n]);
 398       lower_nibble = g_ascii_xdigit_value (str[n + 1]);
 399       if (upper_nibble == -1 || lower_nibble == -1)
 400         {
 401           g_set_error (error,
 402                        G_IO_ERROR,
 403                        G_IO_ERROR_FAILED,
 404                        "Error hexdecoding string `%s' around position %d",
 405                        str, n);
 406           goto out;
 407         }
 408       value = (upper_nibble<<4) | lower_nibble;
 409       g_string_append_c (s, value);
 410     }
 411
 412   ret = g_string_free (s, FALSE);
 413   s = NULL;
 414
 415  out:
 416   if (s != NULL)
 417     g_string_free (s, TRUE);
 418   return ret;
 419 }
 420
 421 /* TODO: take len */
 422 static gchar *
 423 hexencode (const gchar *str)
 424 {
 425   guint n;
 426   GString *s;
 427
 428   s = g_string_new (NULL);
 429   for (n = 0; str[n] != '\0'; n++)
 430     {
 431       gint val;
 432       gint upper_nibble;
 433       gint lower_nibble;
 434
 435       val = ((const guchar *) str)[n];
 436       upper_nibble = val >> 4;
 437       lower_nibble = val & 0x0f;
 438
 439       append_nibble (s, upper_nibble);
 440       append_nibble (s, lower_nibble);
 441     }
 442
 443   return g_string_free (s, FALSE);
 444 }
 445
 446 /* ---------------------------------------------------------------------------------------------------- */
 447
 448 static GDBusAuthMechanism *
 449 client_choose_mech_and_send_initial_response (GDBusAuth           *auth,
 450                                               GCredentials        *credentials_that_were_sent,
 451                                               const gchar* const  *supported_auth_mechs,
 452                                               GPtrArray           *attempted_auth_mechs,
 453                                               GDataOutputStream   *dos,
 454                                               GCancellable        *cancellable,
 455                                               GError             **error)
 456 {
 457   GDBusAuthMechanism *mech;
 458   GType auth_mech_to_use_gtype;
 459   guint n;
 460   guint m;
 461   gchar *initial_response;
 462   gsize initial_response_len;
 463   gchar *encoded;
 464   gchar *s;
 465
 466  again:
 467   mech = NULL;
 468
 469   debug_print ("CLIENT: Trying to choose mechanism");
 470
 471   /* find an authentication mechanism to try, if any */
 472   auth_mech_to_use_gtype = (GType) 0;
 473   for (n = 0; supported_auth_mechs[n] != NULL; n++)
 474     {
 475       gboolean attempted_already;
 476       attempted_already = FALSE;
 477       for (m = 0; m < attempted_auth_mechs->len; m++)
 478         {
 479           if (g_strcmp0 (supported_auth_mechs[n], attempted_auth_mechs->pdata[m]) == 0)
 480             {
 481               attempted_already = TRUE;
 482               break;
 483             }
 484         }
 485       if (!attempted_already)
 486         {
 487           auth_mech_to_use_gtype = find_mech_by_name (auth, supported_auth_mechs[n]);
 488           if (auth_mech_to_use_gtype != (GType) 0)
 489             break;
 490         }
 491     }
 492
 493   if (auth_mech_to_use_gtype == (GType) 0)
 494     {
 495       guint n;
 496       gchar *available;
 497       GString *tried_str;
 498
 499       debug_print ("CLIENT: Exhausted all available mechanisms");
 500
 501       available = g_strjoinv (", ", (gchar **) supported_auth_mechs);
 502
 503       tried_str = g_string_new (NULL);
 504       for (n = 0; n < attempted_auth_mechs->len; n++)
 505         {
 506           if (n > 0)
 507             g_string_append (tried_str, ", ");
 508           g_string_append (tried_str, attempted_auth_mechs->pdata[n]);
 509         }
 510       g_set_error (error,
 511                    G_IO_ERROR,
 512                    G_IO_ERROR_FAILED,
 513                    _("Exhausted all available authentication mechanisms (tried: %s) (available: %s)"),
 514                    tried_str->str,
 515                    available);
 516       g_string_free (tried_str, TRUE);
 517       g_free (available);
 518       goto out;
 519     }
 520
 521   /* OK, decided on a mechanism - let's do this thing */
 522   mech = g_object_new (auth_mech_to_use_gtype,
 523                        "stream", auth->priv->stream,
 524                        "credentials", credentials_that_were_sent,
 525                        NULL);
 526   debug_print ("CLIENT: Trying mechanism `%s'", _g_dbus_auth_mechanism_get_name (auth_mech_to_use_gtype));
 527   g_ptr_array_add (attempted_auth_mechs, (gpointer) _g_dbus_auth_mechanism_get_name (auth_mech_to_use_gtype));
 528
 529   /* the auth mechanism may not be supported
 530    * (for example, EXTERNAL only works if credentials were exchanged)
 531    */
 532   if (!_g_dbus_auth_mechanism_is_supported (mech))
 533     {
 534       debug_print ("CLIENT: Mechanism `%s' says it is not supported", _g_dbus_auth_mechanism_get_name (auth_mech_to_use_gtype));
 535       g_object_unref (mech);
 536       mech = NULL;
 537       goto again;
 538     }
 539
 540   initial_response_len = -1;
 541   initial_response = _g_dbus_auth_mechanism_client_initiate (mech,
 542                                                              &initial_response_len);
 543 #if 0
 544   g_printerr ("using auth mechanism with name `%s' of type `%s' with initial response `%s'\n",
 545               _g_dbus_auth_mechanism_get_name (auth_mech_to_use_gtype),
 546               g_type_name (G_TYPE_FROM_INSTANCE (mech)),
 547               initial_response);
 548 #endif
 549   if (initial_response != NULL)
 550     {
 551       //g_printerr ("initial_response = `%s'\n", initial_response);
 552       encoded = hexencode (initial_response);
 553       s = g_strdup_printf ("AUTH %s %s\r\n",
 554                            _g_dbus_auth_mechanism_get_name (auth_mech_to_use_gtype),
 555                            encoded);
 556       g_free (initial_response);
 557       g_free (encoded);
 558     }
 559   else
 560     {
 561       s = g_strdup_printf ("AUTH %s\r\n", _g_dbus_auth_mechanism_get_name (auth_mech_to_use_gtype));
 562     }
 563   debug_print ("CLIENT: writing `%s'", s);
 564   if (!g_data_output_stream_put_string (dos, s, cancellable, error))
 565     {
 566       g_object_unref (mech);
 567       mech = NULL;
 568       g_free (s);
 569       goto out;
 570     }
 571   g_free (s);
 572
 573  out:
 574   return mech;
 575 }
 576
 577
 578 /* ---------------------------------------------------------------------------------------------------- */
 579
 580 typedef enum
 581 {
 582   CLIENT_STATE_WAITING_FOR_DATA,
 583   CLIENT_STATE_WAITING_FOR_OK,
 584   CLIENT_STATE_WAITING_FOR_REJECT,
 585   CLIENT_STATE_WAITING_FOR_AGREE_UNIX_FD
 586 } ClientState;
 587
 588 gchar *
 589 _g_dbus_auth_run_client (GDBusAuth     *auth,
 590                          GDBusAuthObserver     *observer,
 591                          GDBusCapabilityFlags offered_capabilities,
 592                          GDBusCapabilityFlags *out_negotiated_capabilities,
 593                          GCancellable  *cancellable,
 594                          GError       **error)
 595 {
 596   gchar *s;
 597   GDataInputStream *dis;
 598   GDataOutputStream *dos;
 599   GCredentials *credentials;
 600   gchar *ret_guid;
 601   gchar *line;
 602   gsize line_length;
 603   gchar **supported_auth_mechs;
 604   GPtrArray *attempted_auth_mechs;
 605   GDBusAuthMechanism *mech;
 606   ClientState state;
 607   GDBusCapabilityFlags negotiated_capabilities;
 608
 609   debug_print ("CLIENT: initiating");
 610
 611   _g_dbus_auth_add_mechs (auth, observer);
 612
 613   ret_guid = NULL;
 614   supported_auth_mechs = NULL;
 615   attempted_auth_mechs = g_ptr_array_new ();
 616   mech = NULL;
 617   negotiated_capabilities = 0;
 618   credentials = NULL;
 619
 620   dis = G_DATA_INPUT_STREAM (g_data_input_stream_new (g_io_stream_get_input_stream (auth->priv->stream)));
 621   dos = G_DATA_OUTPUT_STREAM (g_data_output_stream_new (g_io_stream_get_output_stream (auth->priv->stream)));
 622   g_filter_input_stream_set_close_base_stream (G_FILTER_INPUT_STREAM (dis), FALSE);
 623   g_filter_output_stream_set_close_base_stream (G_FILTER_OUTPUT_STREAM (dos), FALSE);
 624
 625   g_data_input_stream_set_newline_type (dis, G_DATA_STREAM_NEWLINE_TYPE_CR_LF);
 626
 627 #ifdef G_OS_UNIX
 628   if (G_IS_UNIX_CONNECTION (auth->priv->stream))
 629     {
 630       credentials = g_credentials_new ();
 631       if (!g_unix_connection_send_credentials (G_UNIX_CONNECTION (auth->priv->stream),
 632                                                cancellable,
 633                                                error))
 634         goto out;
 635     }
 636   else
 637     {
 638       if (!g_data_output_stream_put_byte (dos, '\0', cancellable, error))
 639         goto out;
 640     }
 641 #else
 642   if (!g_data_output_stream_put_byte (dos, '\0', cancellable, error))
 643     goto out;
 644 #endif
 645
 646   if (credentials != NULL)
 647     {
 648       if (G_UNLIKELY (_g_dbus_debug_authentication ()))
 649         {
 650           s = g_credentials_to_string (credentials);
 651           debug_print ("CLIENT: sent credentials `%s'", s);
 652           g_free (s);
 653         }
 654     }
 655   else
 656     {
 657       debug_print ("CLIENT: didn't send any credentials");
 658     }
 659
 660   /* TODO: to reduce roundtrips, try to pick an auth mechanism to start with */
 661
 662   /* Get list of supported authentication mechanisms */
 663   s = "AUTH\r\n";
 664   debug_print ("CLIENT: writing `%s'", s);
 665   if (!g_data_output_stream_put_string (dos, s, cancellable, error))
 666     goto out;
 667   state = CLIENT_STATE_WAITING_FOR_REJECT;
 668
 669   while (TRUE)
 670     {
 671       switch (state)
 672         {
 673         case CLIENT_STATE_WAITING_FOR_REJECT:
 674           debug_print ("CLIENT: WaitingForReject");
 675           line = _my_g_data_input_stream_read_line (dis, &line_length, cancellable, error);
 676           if (line == NULL)
 677             goto out;
 678           debug_print ("CLIENT: WaitingForReject, read '%s'", line);
 679
 680         choose_mechanism:
 681           if (!g_str_has_prefix (line, "REJECTED "))
 682             {
 683               g_set_error (error,
 684                            G_IO_ERROR,
 685                            G_IO_ERROR_FAILED,
 686                            "In WaitingForReject: Expected `REJECTED am1 am2 ... amN', got `%s'",
 687                            line);
 688               g_free (line);
 689               goto out;
 690             }
 691           if (supported_auth_mechs == NULL)
 692             {
 693               supported_auth_mechs = g_strsplit (line + sizeof ("REJECTED ") - 1, " ", 0);
 694 #if 0
 695               for (n = 0; supported_auth_mechs != NULL && supported_auth_mechs[n] != NULL; n++)
 696                 g_printerr ("supported_auth_mechs[%d] = `%s'\n", n, supported_auth_mechs[n]);
 697 #endif
 698             }
 699           g_free (line);
 700           mech = client_choose_mech_and_send_initial_response (auth,
 701                                                                credentials,
 702                                                                (const gchar* const *) supported_auth_mechs,
 703                                                                attempted_auth_mechs,
 704                                                                dos,
 705                                                                cancellable,
 706                                                                error);
 707           if (mech == NULL)
 708             goto out;
 709           if (_g_dbus_auth_mechanism_client_get_state (mech) == G_DBUS_AUTH_MECHANISM_STATE_WAITING_FOR_DATA)
 710             state = CLIENT_STATE_WAITING_FOR_DATA;
 711           else
 712             state = CLIENT_STATE_WAITING_FOR_OK;
 713           break;
 714
 715         case CLIENT_STATE_WAITING_FOR_OK:
 716           debug_print ("CLIENT: WaitingForOK");
 717           line = _my_g_data_input_stream_read_line (dis, &line_length, cancellable, error);
 718           if (line == NULL)
 719             goto out;
 720           debug_print ("CLIENT: WaitingForOK, read `%s'", line);
 721           if (g_str_has_prefix (line, "OK "))
 722             {
 723               if (!g_dbus_is_guid (line + 3))
 724                 {
 725                   g_set_error (error,
 726                                G_IO_ERROR,
 727                                G_IO_ERROR_FAILED,
 728                                "Invalid OK response `%s'",
 729                                line);
 730                   g_free (line);
 731                   goto out;
 732                 }
 733               ret_guid = g_strdup (line + 3);
 734               g_free (line);
 735
 736               if (offered_capabilities & G_DBUS_CAPABILITY_FLAGS_UNIX_FD_PASSING)
 737                 {
 738                   s = "NEGOTIATE_UNIX_FD\r\n";
 739                   debug_print ("CLIENT: writing `%s'", s);
 740                   if (!g_data_output_stream_put_string (dos, s, cancellable, error))
 741                     goto out;
 742                   state = CLIENT_STATE_WAITING_FOR_AGREE_UNIX_FD;
 743                 }
 744               else
 745                 {
 746                   s = "BEGIN\r\n";
 747                   debug_print ("CLIENT: writing `%s'", s);
 748                   if (!g_data_output_stream_put_string (dos, s, cancellable, error))
 749                     goto out;
 750                   /* and we're done! */
 751                   goto out;
 752                 }
 753             }
 754           else if (g_str_has_prefix (line, "REJECTED "))
 755             {
 756               goto choose_mechanism;
 757             }
 758           else
 759             {
 760               /* TODO: handle other valid responses */
 761               g_set_error (error,
 762                            G_IO_ERROR,
 763                            G_IO_ERROR_FAILED,
 764                            "In WaitingForOk: unexpected response `%s'",
 765                            line);
 766               g_free (line);
 767               goto out;
 768             }
 769           break;
 770
 771         case CLIENT_STATE_WAITING_FOR_AGREE_UNIX_FD:
 772           debug_print ("CLIENT: WaitingForAgreeUnixFD");
 773           line = _my_g_data_input_stream_read_line (dis, &line_length, cancellable, error);
 774           if (line == NULL)
 775             goto out;
 776           debug_print ("CLIENT: WaitingForAgreeUnixFD, read=`%s'", line);
 777           if (g_strcmp0 (line, "AGREE_UNIX_FD") == 0)
 778             {
 779               g_free (line);
 780               negotiated_capabilities |= G_DBUS_CAPABILITY_FLAGS_UNIX_FD_PASSING;
 781               s = "BEGIN\r\n";
 782               debug_print ("CLIENT: writing `%s'", s);
 783               if (!g_data_output_stream_put_string (dos, s, cancellable, error))
 784                 goto out;
 785               /* and we're done! */
 786               goto out;
 787             }
 788           else if (g_str_has_prefix (line, "ERROR") && (line[5] == 0 || g_ascii_isspace (line[5])))
 789             {
 790               //g_strstrip (line + 5); g_debug ("bah, no unix_fd: `%s'", line + 5);
 791               g_free (line);
 792               s = "BEGIN\r\n";
 793               debug_print ("CLIENT: writing `%s'", s);
 794               if (!g_data_output_stream_put_string (dos, s, cancellable, error))
 795                 goto out;
 796               /* and we're done! */
 797               goto out;
 798             }
 799           else
 800             {
 801               /* TODO: handle other valid responses */
 802               g_set_error (error,
 803                            G_IO_ERROR,
 804                            G_IO_ERROR_FAILED,
 805                            "In WaitingForAgreeUnixFd: unexpected response `%s'",
 806                            line);
 807               g_free (line);
 808               goto out;
 809             }
 810           break;
 811
 812         case CLIENT_STATE_WAITING_FOR_DATA:
 813           debug_print ("CLIENT: WaitingForData");
 814           line = _my_g_data_input_stream_read_line (dis, &line_length, cancellable, error);
 815           if (line == NULL)
 816             goto out;
 817           debug_print ("CLIENT: WaitingForData, read=`%s'", line);
 818           if (g_str_has_prefix (line, "DATA "))
 819             {
 820               gchar *encoded;
 821               gchar *decoded_data;
 822               gsize decoded_data_len = 0;
 823
 824               encoded = g_strdup (line + 5);
 825               g_free (line);
 826               g_strstrip (encoded);
 827               decoded_data = hexdecode (encoded, &decoded_data_len, error);
 828               g_free (encoded);
 829               if (decoded_data == NULL)
 830                 {
 831                   g_prefix_error (error, "DATA response is malformed: ");
 832                   /* invalid encoding, disconnect! */
 833                   goto out;
 834                 }
 835               _g_dbus_auth_mechanism_client_data_receive (mech, decoded_data, decoded_data_len);
 836               g_free (decoded_data);
 837
 838               if (_g_dbus_auth_mechanism_client_get_state (mech) == G_DBUS_AUTH_MECHANISM_STATE_HAVE_DATA_TO_SEND)
 839                 {
 840                   gchar *data;
 841                   gsize data_len;
 842                   gchar *encoded_data;
 843                   data = _g_dbus_auth_mechanism_client_data_send (mech, &data_len);
 844                   encoded_data = hexencode (data);
 845                   s = g_strdup_printf ("DATA %s\r\n", encoded_data);
 846                   g_free (encoded_data);
 847                   g_free (data);
 848                   debug_print ("CLIENT: writing `%s'", s);
 849                   if (!g_data_output_stream_put_string (dos, s, cancellable, error))
 850                     {
 851                       g_free (s);
 852                       goto out;
 853                     }
 854                   g_free (s);
 855                 }
 856               state = CLIENT_STATE_WAITING_FOR_OK;
 857             }
 858           else if (g_str_has_prefix (line, "REJECTED "))
 859             {
 860               /* could be the chosen authentication method just doesn't work. Try
 861                * another one...
 862                */
 863               goto choose_mechanism;
 864             }
 865           else
 866             {
 867               g_set_error (error,
 868                            G_IO_ERROR,
 869                            G_IO_ERROR_FAILED,
 870                            "In WaitingForData: unexpected response `%s'",
 871                            line);
 872               g_free (line);
 873               goto out;
 874             }
 875           break;
 876
 877         default:
 878           g_assert_not_reached ();
 879           break;
 880         }
 881
 882     }; /* main authentication client loop */
 883
 884  out:
 885   if (mech != NULL)
 886     g_object_unref (mech);
 887   g_ptr_array_unref (attempted_auth_mechs);
 888   g_strfreev (supported_auth_mechs);
 889   g_object_unref (dis);
 890   g_object_unref (dos);
 891
 892   /* ensure return value is NULL if error is set */
 893   if (error != NULL && *error != NULL)
 894     {
 895       g_free (ret_guid);
 896       ret_guid = NULL;
 897     }
 898
 899   if (ret_guid != NULL)
 900     {
 901       if (out_negotiated_capabilities != NULL)
 902         *out_negotiated_capabilities = negotiated_capabilities;
 903     }
 904
 905   if (credentials != NULL)
 906     g_object_unref (credentials);
 907
 908   debug_print ("CLIENT: Done, authenticated=%d", ret_guid != NULL);
 909
 910   return ret_guid;
 911 }
 912
 913 /* ---------------------------------------------------------------------------------------------------- */
 914
 915 static gchar *
 916 get_auth_mechanisms (GDBusAuth     *auth,
 917                      gboolean       allow_anonymous,
 918                      const gchar   *prefix,
 919                      const gchar   *suffix,
 920                      const gchar   *separator)
 921 {
 922   GList *l;
 923   GString *str;
 924   gboolean need_sep;
 925
 926   str = g_string_new (prefix);
 927   need_sep = FALSE;
 928   for (l = auth->priv->available_mechanisms; l != NULL; l = l->next)
 929     {
 930       Mechanism *m = l->data;
 931
 932       if (!allow_anonymous && g_strcmp0 (m->name, "ANONYMOUS") == 0)
 933         continue;
 934
 935       if (need_sep)
 936         g_string_append (str, separator);
 937       g_string_append (str, m->name);
 938       need_sep = TRUE;
 939     }
 940
 941   g_string_append (str, suffix);
 942   return g_string_free (str, FALSE);
 943 }
 944
 945
 946 typedef enum
 947 {
 948   SERVER_STATE_WAITING_FOR_AUTH,
 949   SERVER_STATE_WAITING_FOR_DATA,
 950   SERVER_STATE_WAITING_FOR_BEGIN
 951 } ServerState;
 952
 953 gboolean
 954 _g_dbus_auth_run_server (GDBusAuth              *auth,
 955                          GDBusAuthObserver      *observer,
 956                          const gchar            *guid,
 957                          gboolean                allow_anonymous,
 958                          GDBusCapabilityFlags    offered_capabilities,
 959                          GDBusCapabilityFlags   *out_negotiated_capabilities,
 960                          GCredentials          **out_received_credentials,
 961                          GCancellable           *cancellable,
 962                          GError                **error)
 963 {
 964   gboolean ret;
 965   ServerState state;
 966   GDataInputStream *dis;
 967   GDataOutputStream *dos;
 968   GError *local_error;
 969   guchar byte;
 970   gchar *line;
 971   gsize line_length;
 972   GDBusAuthMechanism *mech;
 973   gchar *s;
 974   GDBusCapabilityFlags negotiated_capabilities;
 975   GCredentials *credentials;
 976
 977   debug_print ("SERVER: initiating");
 978
 979   _g_dbus_auth_add_mechs (auth, observer);
 980
 981   ret = FALSE;
 982   dis = NULL;
 983   dos = NULL;
 984   mech = NULL;
 985   negotiated_capabilities = 0;
 986   credentials = NULL;
 987
 988   if (!g_dbus_is_guid (guid))
 989     {
 990       g_set_error (error,
 991                    G_IO_ERROR,
 992                    G_IO_ERROR_FAILED,
 993                    "The given guid `%s' is not valid",
 994                    guid);
 995       goto out;
 996     }
 997
 998   dis = G_DATA_INPUT_STREAM (g_data_input_stream_new (g_io_stream_get_input_stream (auth->priv->stream)));
 999   dos = G_DATA_OUTPUT_STREAM (g_data_output_stream_new (g_io_stream_get_output_stream (auth->priv->stream)));
1000   g_filter_input_stream_set_close_base_stream (G_FILTER_INPUT_STREAM (dis), FALSE);
1001   g_filter_output_stream_set_close_base_stream (G_FILTER_OUTPUT_STREAM (dos), FALSE);
1002
1003   g_data_input_stream_set_newline_type (dis, G_DATA_STREAM_NEWLINE_TYPE_CR_LF);
1004
1005   /* first read the NUL-byte (TODO: read credentials if using a unix domain socket) */
1006 #ifdef G_OS_UNIX
1007   if (G_IS_UNIX_CONNECTION (auth->priv->stream))
1008     {
1009       local_error = NULL;
1010       credentials = g_unix_connection_receive_credentials (G_UNIX_CONNECTION (auth->priv->stream),
1011                                                            cancellable,
1012                                                            &local_error);
1013       if (credentials == NULL && !g_error_matches (local_error, G_IO_ERROR, G_IO_ERROR_NOT_SUPPORTED))
1014         {
1015           g_propagate_error (error, local_error);
1016           goto out;
1017         }
1018     }
1019   else
1020     {
1021       local_error = NULL;
1022       byte = g_data_input_stream_read_byte (dis, cancellable, &local_error);
1023       byte = byte; /* To avoid -Wunused-but-set-variable */
1024       if (local_error != NULL)
1025         {
1026           g_propagate_error (error, local_error);
1027           goto out;
1028         }
1029     }
1030 #else
1031   local_error = NULL;
1032   byte = g_data_input_stream_read_byte (dis, cancellable, &local_error);
1033   if (local_error != NULL)
1034     {
1035       g_propagate_error (error, local_error);
1036       goto out;
1037     }
1038 #endif
1039   if (credentials != NULL)
1040     {
1041       if (G_UNLIKELY (_g_dbus_debug_authentication ()))
1042         {
1043           s = g_credentials_to_string (credentials);
1044           debug_print ("SERVER: received credentials `%s'", s);
1045           g_free (s);
1046         }
1047     }
1048   else
1049     {
1050       debug_print ("SERVER: didn't receive any credentials");
1051     }
1052
1053   state = SERVER_STATE_WAITING_FOR_AUTH;
1054   while (TRUE)
1055     {
1056       switch (state)
1057         {
1058         case SERVER_STATE_WAITING_FOR_AUTH:
1059           debug_print ("SERVER: WaitingForAuth");
1060           line = _my_g_data_input_stream_read_line (dis, &line_length, cancellable, error);
1061           debug_print ("SERVER: WaitingForAuth, read `%s'", line);
1062           if (line == NULL)
1063             goto out;
1064           if (g_strcmp0 (line, "AUTH") == 0)
1065             {
1066               s = get_auth_mechanisms (auth, allow_anonymous, "REJECTED ", "\r\n", " ");
1067               debug_print ("SERVER: writing `%s'", s);
1068               if (!g_data_output_stream_put_string (dos, s, cancellable, error))
1069                 {
1070                   g_free (s);
1071                   goto out;
1072                 }
1073               g_free (s);
1074               g_free (line);
1075             }
1076           else if (g_str_has_prefix (line, "AUTH "))
1077             {
1078               gchar **tokens;
1079               const gchar *encoded;
1080               const gchar *mech_name;
1081               GType auth_mech_to_use_gtype;
1082
1083               tokens = g_strsplit (line, " ", 0);
1084               g_free (line);
1085
1086               switch (g_strv_length (tokens))
1087                 {
1088                 case 2:
1089                   /* no initial response */
1090                   mech_name = tokens[1];
1091                   encoded = NULL;
1092                   break;
1093
1094                 case 3:
1095                   /* initial response */
1096                   mech_name = tokens[1];
1097                   encoded = tokens[2];
1098                   break;
1099
1100                 default:
1101                   g_set_error (error,
1102                                G_IO_ERROR,
1103                                G_IO_ERROR_FAILED,
1104                                "Unexpected line `%s' while in WaitingForAuth state",
1105                                line);
1106                   g_strfreev (tokens);
1107                   goto out;
1108                 }
1109
1110               /* TODO: record that the client has attempted to use this mechanism */
1111               //g_debug ("client is trying `%s'", mech_name);
1112
1113               auth_mech_to_use_gtype = find_mech_by_name (auth, mech_name);
1114               if ((auth_mech_to_use_gtype == (GType) 0) ||
1115                   (!allow_anonymous && g_strcmp0 (mech_name, "ANONYMOUS") == 0))
1116                 {
1117                   /* We don't support this auth mechanism */
1118                   g_strfreev (tokens);
1119                   s = get_auth_mechanisms (auth, allow_anonymous, "REJECTED ", "\r\n", " ");
1120                   debug_print ("SERVER: writing `%s'", s);
1121                   if (!g_data_output_stream_put_string (dos, s, cancellable, error))
1122                     {
1123                       g_free (s);
1124                       goto out;
1125                     }
1126                   g_free (s);
1127
1128                   /* stay in WAITING FOR AUTH */
1129                   state = SERVER_STATE_WAITING_FOR_AUTH;
1130                 }
1131               else
1132                 {
1133                   gchar *initial_response;
1134                   gsize initial_response_len;
1135
1136                   mech = g_object_new (auth_mech_to_use_gtype,
1137                                        "stream", auth->priv->stream,
1138                                        "credentials", credentials,
1139                                        NULL);
1140
1141                   initial_response = NULL;
1142                   initial_response_len = 0;
1143                   if (encoded != NULL)
1144                     {
1145                       initial_response = hexdecode (encoded, &initial_response_len, error);
1146                       if (initial_response == NULL)
1147                         {
1148                           g_prefix_error (error, "Initial response is malformed: ");
1149                           /* invalid encoding, disconnect! */
1150                           g_strfreev (tokens);
1151                           goto out;
1152                         }
1153                     }
1154
1155                   _g_dbus_auth_mechanism_server_initiate (mech,
1156                                                           initial_response,
1157                                                           initial_response_len);
1158                   g_free (initial_response);
1159                   g_strfreev (tokens);
1160
1161                 change_state:
1162                   switch (_g_dbus_auth_mechanism_server_get_state (mech))
1163                     {
1164                     case G_DBUS_AUTH_MECHANISM_STATE_ACCEPTED:
1165                       if (observer != NULL &&
1166                           !g_dbus_auth_observer_authorize_authenticated_peer (observer,
1167                                                                               auth->priv->stream,
1168                                                                               credentials))
1169                         {
1170                           /* disconnect */
1171                           g_set_error_literal (error,
1172                                                G_IO_ERROR,
1173                                                G_IO_ERROR_FAILED,
1174                                                _("Cancelled via GDBusAuthObserver::authorize-authenticated-peer"));
1175                           goto out;
1176                         }
1177                       else
1178                         {
1179                           s = g_strdup_printf ("OK %s\r\n", guid);
1180                           debug_print ("SERVER: writing `%s'", s);
1181                           if (!g_data_output_stream_put_string (dos, s, cancellable, error))
1182                             {
1183                               g_free (s);
1184                               goto out;
1185                             }
1186                           g_free (s);
1187                           state = SERVER_STATE_WAITING_FOR_BEGIN;
1188                         }
1189                       break;
1190
1191                     case G_DBUS_AUTH_MECHANISM_STATE_REJECTED:
1192                       s = get_auth_mechanisms (auth, allow_anonymous, "REJECTED ", "\r\n", " ");
1193                       debug_print ("SERVER: writing `%s'", s);
1194                       if (!g_data_output_stream_put_string (dos, s, cancellable, error))
1195                         {
1196                           g_free (s);
1197                           goto out;
1198                         }
1199                       g_free (s);
1200                       state = SERVER_STATE_WAITING_FOR_AUTH;
1201                       break;
1202
1203                     case G_DBUS_AUTH_MECHANISM_STATE_WAITING_FOR_DATA:
1204                       state = SERVER_STATE_WAITING_FOR_DATA;
1205                       break;
1206
1207                     case G_DBUS_AUTH_MECHANISM_STATE_HAVE_DATA_TO_SEND:
1208                       {
1209                         gchar *data;
1210                         gsize data_len;
1211                         gchar *encoded_data;
1212                         data = _g_dbus_auth_mechanism_server_data_send (mech, &data_len);
1213                         encoded_data = hexencode (data);
1214                         s = g_strdup_printf ("DATA %s\r\n", encoded_data);
1215                         g_free (encoded_data);
1216                         g_free (data);
1217                         debug_print ("SERVER: writing `%s'", s);
1218                         if (!g_data_output_stream_put_string (dos, s, cancellable, error))
1219                           {
1220                             g_free (s);
1221                             goto out;
1222                           }
1223                         g_free (s);
1224                       }
1225                       goto change_state;
1226                       break;
1227
1228                     default:
1229                       /* TODO */
1230                       g_assert_not_reached ();
1231                       break;
1232                     }
1233                 }
1234             }
1235           else
1236             {
1237               g_set_error (error,
1238                            G_IO_ERROR,
1239                            G_IO_ERROR_FAILED,
1240                            "Unexpected line `%s' while in WaitingForAuth state",
1241                            line);
1242               g_free (line);
1243               goto out;
1244             }
1245           break;
1246
1247         case SERVER_STATE_WAITING_FOR_DATA:
1248           debug_print ("SERVER: WaitingForData");
1249           line = _my_g_data_input_stream_read_line (dis, &line_length, cancellable, error);
1250           debug_print ("SERVER: WaitingForData, read `%s'", line);
1251           if (line == NULL)
1252             goto out;
1253           if (g_str_has_prefix (line, "DATA "))
1254             {
1255               gchar *encoded;
1256               gchar *decoded_data;
1257               gsize decoded_data_len = 0;
1258
1259               encoded = g_strdup (line + 5);
1260               g_free (line);
1261               g_strstrip (encoded);
1262               decoded_data = hexdecode (encoded, &decoded_data_len, error);
1263               g_free (encoded);
1264               if (decoded_data == NULL)
1265                 {
1266                   g_prefix_error (error, "DATA response is malformed: ");
1267                   /* invalid encoding, disconnect! */
1268                   goto out;
1269                 }
1270               _g_dbus_auth_mechanism_server_data_receive (mech, decoded_data, decoded_data_len);
1271               g_free (decoded_data);
1272               /* oh man, this goto-crap is so ugly.. really need to rewrite the state machine */
1273               goto change_state;
1274             }
1275           else
1276             {
1277               g_set_error (error,
1278                            G_IO_ERROR,
1279                            G_IO_ERROR_FAILED,
1280                            "Unexpected line `%s' while in WaitingForData state",
1281                            line);
1282               g_free (line);
1283             }
1284           goto out;
1285
1286         case SERVER_STATE_WAITING_FOR_BEGIN:
1287           debug_print ("SERVER: WaitingForBegin");
1288           /* Use extremely slow (but reliable) line reader - this basically
1289            * does a recvfrom() system call per character
1290            *
1291            * (the problem with using GDataInputStream's read_line is that because of
1292            * buffering it might start reading into the first D-Bus message that
1293            * appears after "BEGIN\r\n"....)
1294            */
1295           line = _my_g_input_stream_read_line_safe (g_io_stream_get_input_stream (auth->priv->stream),
1296                                                     &line_length,
1297                                                     cancellable,
1298                                                     error);
1299           debug_print ("SERVER: WaitingForBegin, read `%s'", line);
1300           if (line == NULL)
1301             goto out;
1302           if (g_strcmp0 (line, "BEGIN") == 0)
1303             {
1304               /* YAY, done! */
1305               ret = TRUE;
1306               g_free (line);
1307               goto out;
1308             }
1309           else if (g_strcmp0 (line, "NEGOTIATE_UNIX_FD") == 0)
1310             {
1311               g_free (line);
1312               if (offered_capabilities & G_DBUS_CAPABILITY_FLAGS_UNIX_FD_PASSING)
1313                 {
1314                   negotiated_capabilities |= G_DBUS_CAPABILITY_FLAGS_UNIX_FD_PASSING;
1315                   s = "AGREE_UNIX_FD\r\n";
1316                   debug_print ("SERVER: writing `%s'", s);
1317                   if (!g_data_output_stream_put_string (dos, s, cancellable, error))
1318                     goto out;
1319                 }
1320               else
1321                 {
1322                   s = "ERROR \"fd passing not offered\"\r\n";
1323                   debug_print ("SERVER: writing `%s'", s);
1324                   if (!g_data_output_stream_put_string (dos, s, cancellable, error))
1325                     goto out;
1326                 }
1327             }
1328           else
1329             {
1330               g_debug ("Unexpected line `%s' while in WaitingForBegin state", line);
1331               g_free (line);
1332               s = "ERROR \"Unknown Command\"\r\n";
1333               debug_print ("SERVER: writing `%s'", s);
1334               if (!g_data_output_stream_put_string (dos, s, cancellable, error))
1335                 goto out;
1336             }
1337           break;
1338
1339         default:
1340           g_assert_not_reached ();
1341           break;
1342         }
1343     }
1344
1345
1346   g_set_error_literal (error,
1347                        G_IO_ERROR,
1348                        G_IO_ERROR_FAILED,
1349                        "Not implemented (server)");
1350
1351  out:
1352   if (mech != NULL)
1353     g_object_unref (mech);
1354   if (dis != NULL)
1355     g_object_unref (dis);
1356   if (dos != NULL)
1357     g_object_unref (dos);
1358
1359   /* ensure return value is FALSE if error is set */
1360   if (error != NULL && *error != NULL)
1361     {
1362       ret = FALSE;
1363     }
1364
1365   if (ret)
1366     {
1367       if (out_negotiated_capabilities != NULL)
1368         *out_negotiated_capabilities = negotiated_capabilities;
1369       if (out_received_credentials != NULL)
1370         *out_received_credentials = credentials != NULL ? g_object_ref (credentials) : NULL;
1371     }
1372
1373   if (credentials != NULL)
1374     g_object_unref (credentials);
1375
1376   debug_print ("SERVER: Done, authenticated=%d", ret);
1377
1378   return ret;
1379 }
1380
1381 /* ---------------------------------------------------------------------------------------------------- */