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