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 2.1 of the License, or (at your option) any later version.
9 *
10 * This library is distributed in the hope that it will be useful,
11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 * Lesser General Public License for more details.
14 *
15 * You should have received a copy of the GNU Lesser General
16 * Public License along with this library; if not, see <http://www.gnu.org/licenses/>.
17 *
18 * Author: David Zeuthen <davidz@redhat.com>
19 */
20
21 #include "config.h"
22
23 #include "gdbusauth.h"
24
25 #include "gdbusauthmechanismanon.h"
26 #include "gdbusauthmechanismexternal.h"
27 #include "gdbusauthmechanismsha1.h"
28 #include "gdbusauthobserver.h"
29
30 #include "gdbuserror.h"
31 #include "gdbusutils.h"
32 #include "gioenumtypes.h"
33 #include "gcredentials.h"
34 #include "gcredentialsprivate.h"
35 #include "gdbusprivate.h"
36 #include "giostream.h"
37 #include "gdatainputstream.h"
38 #include "gdataoutputstream.h"
39
40 #ifdef G_OS_UNIX
41 #include "gnetworking.h"
42 #include "gunixconnection.h"
43 #include "gunixcredentialsmessage.h"
44 #endif
45
46 #include "glibintl.h"
47
48 G_GNUC_PRINTF(1, 2)
49 static void
debug_print(const gchar * message,...)50 debug_print (const gchar *message, ...)
51 {
52 if (G_UNLIKELY (_g_dbus_debug_authentication ()))
53 {
54 gchar *s;
55 GString *str;
56 va_list var_args;
57 guint n;
58
59 _g_dbus_debug_print_lock ();
60
61 va_start (var_args, message);
62 s = g_strdup_vprintf (message, var_args);
63 va_end (var_args);
64
65 str = g_string_new (NULL);
66 for (n = 0; s[n] != '\0'; n++)
67 {
68 if (G_UNLIKELY (s[n] == '\r'))
69 g_string_append (str, "\\r");
70 else if (G_UNLIKELY (s[n] == '\n'))
71 g_string_append (str, "\\n");
72 else
73 g_string_append_c (str, s[n]);
74 }
75 g_print ("GDBus-debug:Auth: %s\n", str->str);
76 g_string_free (str, TRUE);
77 g_free (s);
78
79 _g_dbus_debug_print_unlock ();
80 }
81 }
82
83 typedef struct
84 {
85 const gchar *name;
86 gint priority;
87 GType gtype;
88 } Mechanism;
89
90 static void mechanism_free (Mechanism *m);
91
92 struct _GDBusAuthPrivate
93 {
94 GIOStream *stream;
95
96 /* A list of available Mechanism, sorted according to priority */
97 GList *available_mechanisms;
98 };
99
100 enum
101 {
102 PROP_0,
103 PROP_STREAM
104 };
105
G_DEFINE_TYPE_WITH_PRIVATE(GDBusAuth,_g_dbus_auth,G_TYPE_OBJECT)106 G_DEFINE_TYPE_WITH_PRIVATE (GDBusAuth, _g_dbus_auth, G_TYPE_OBJECT)
107
108 /* ---------------------------------------------------------------------------------------------------- */
109
110 static void
111 _g_dbus_auth_finalize (GObject *object)
112 {
113 GDBusAuth *auth = G_DBUS_AUTH (object);
114
115 if (auth->priv->stream != NULL)
116 g_object_unref (auth->priv->stream);
117 g_list_free_full (auth->priv->available_mechanisms, (GDestroyNotify) mechanism_free);
118
119 if (G_OBJECT_CLASS (_g_dbus_auth_parent_class)->finalize != NULL)
120 G_OBJECT_CLASS (_g_dbus_auth_parent_class)->finalize (object);
121 }
122
123 static void
_g_dbus_auth_get_property(GObject * object,guint prop_id,GValue * value,GParamSpec * pspec)124 _g_dbus_auth_get_property (GObject *object,
125 guint prop_id,
126 GValue *value,
127 GParamSpec *pspec)
128 {
129 GDBusAuth *auth = G_DBUS_AUTH (object);
130
131 switch (prop_id)
132 {
133 case PROP_STREAM:
134 g_value_set_object (value, auth->priv->stream);
135 break;
136
137 default:
138 G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
139 break;
140 }
141 }
142
143 static void
_g_dbus_auth_set_property(GObject * object,guint prop_id,const GValue * value,GParamSpec * pspec)144 _g_dbus_auth_set_property (GObject *object,
145 guint prop_id,
146 const GValue *value,
147 GParamSpec *pspec)
148 {
149 GDBusAuth *auth = G_DBUS_AUTH (object);
150
151 switch (prop_id)
152 {
153 case PROP_STREAM:
154 auth->priv->stream = g_value_dup_object (value);
155 break;
156
157 default:
158 G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
159 break;
160 }
161 }
162
163 static void
_g_dbus_auth_class_init(GDBusAuthClass * klass)164 _g_dbus_auth_class_init (GDBusAuthClass *klass)
165 {
166 GObjectClass *gobject_class;
167
168 gobject_class = G_OBJECT_CLASS (klass);
169 gobject_class->get_property = _g_dbus_auth_get_property;
170 gobject_class->set_property = _g_dbus_auth_set_property;
171 gobject_class->finalize = _g_dbus_auth_finalize;
172
173 g_object_class_install_property (gobject_class,
174 PROP_STREAM,
175 g_param_spec_object ("stream",
176 P_("IO Stream"),
177 P_("The underlying GIOStream used for I/O"),
178 G_TYPE_IO_STREAM,
179 G_PARAM_READABLE |
180 G_PARAM_WRITABLE |
181 G_PARAM_CONSTRUCT_ONLY |
182 G_PARAM_STATIC_NAME |
183 G_PARAM_STATIC_BLURB |
184 G_PARAM_STATIC_NICK));
185 }
186
187 static void
mechanism_free(Mechanism * m)188 mechanism_free (Mechanism *m)
189 {
190 g_free (m);
191 }
192
193 static void
add_mechanism(GDBusAuth * auth,GDBusAuthObserver * observer,GType mechanism_type)194 add_mechanism (GDBusAuth *auth,
195 GDBusAuthObserver *observer,
196 GType mechanism_type)
197 {
198 const gchar *name;
199
200 name = _g_dbus_auth_mechanism_get_name (mechanism_type);
201 if (observer == NULL || g_dbus_auth_observer_allow_mechanism (observer, name))
202 {
203 Mechanism *m;
204 m = g_new0 (Mechanism, 1);
205 m->name = name;
206 m->priority = _g_dbus_auth_mechanism_get_priority (mechanism_type);
207 m->gtype = mechanism_type;
208 auth->priv->available_mechanisms = g_list_prepend (auth->priv->available_mechanisms, m);
209 }
210 }
211
212 static gint
mech_compare_func(Mechanism * a,Mechanism * b)213 mech_compare_func (Mechanism *a, Mechanism *b)
214 {
215 gint ret;
216 /* ensure deterministic order */
217 ret = b->priority - a->priority;
218 if (ret == 0)
219 ret = g_strcmp0 (b->name, a->name);
220 return ret;
221 }
222
223 static void
_g_dbus_auth_init(GDBusAuth * auth)224 _g_dbus_auth_init (GDBusAuth *auth)
225 {
226 auth->priv = _g_dbus_auth_get_instance_private (auth);
227 }
228
229 static void
_g_dbus_auth_add_mechs(GDBusAuth * auth,GDBusAuthObserver * observer)230 _g_dbus_auth_add_mechs (GDBusAuth *auth,
231 GDBusAuthObserver *observer)
232 {
233 /* TODO: trawl extension points */
234 add_mechanism (auth, observer, G_TYPE_DBUS_AUTH_MECHANISM_ANON);
235 add_mechanism (auth, observer, G_TYPE_DBUS_AUTH_MECHANISM_SHA1);
236 add_mechanism (auth, observer, G_TYPE_DBUS_AUTH_MECHANISM_EXTERNAL);
237
238 auth->priv->available_mechanisms = g_list_sort (auth->priv->available_mechanisms,
239 (GCompareFunc) mech_compare_func);
240 }
241
242 static GType
find_mech_by_name(GDBusAuth * auth,const gchar * name)243 find_mech_by_name (GDBusAuth *auth,
244 const gchar *name)
245 {
246 GType ret;
247 GList *l;
248
249 ret = (GType) 0;
250
251 for (l = auth->priv->available_mechanisms; l != NULL; l = l->next)
252 {
253 Mechanism *m = l->data;
254 if (g_strcmp0 (name, m->name) == 0)
255 {
256 ret = m->gtype;
257 goto out;
258 }
259 }
260
261 out:
262 return ret;
263 }
264
265 GDBusAuth *
_g_dbus_auth_new(GIOStream * stream)266 _g_dbus_auth_new (GIOStream *stream)
267 {
268 return g_object_new (G_TYPE_DBUS_AUTH,
269 "stream", stream,
270 NULL);
271 }
272
273 /* ---------------------------------------------------------------------------------------------------- */
274 /* like g_data_input_stream_read_line() but sets error if there's no content to read */
275 static gchar *
_my_g_data_input_stream_read_line(GDataInputStream * dis,gsize * out_line_length,GCancellable * cancellable,GError ** error)276 _my_g_data_input_stream_read_line (GDataInputStream *dis,
277 gsize *out_line_length,
278 GCancellable *cancellable,
279 GError **error)
280 {
281 gchar *ret;
282
283 g_return_val_if_fail (error == NULL || *error == NULL, NULL);
284
285 ret = g_data_input_stream_read_line (dis,
286 out_line_length,
287 cancellable,
288 error);
289 if (ret == NULL && error != NULL && *error == NULL)
290 {
291 g_set_error_literal (error,
292 G_IO_ERROR,
293 G_IO_ERROR_FAILED,
294 _("Unexpected lack of content trying to read a line"));
295 }
296
297 return ret;
298 }
299
300 /* This function is to avoid situations like this
301 *
302 * BEGIN\r\nl\0\0\1...
303 *
304 * e.g. where we read into the first D-Bus message while waiting for
305 * the final line from the client (TODO: file bug against gio for
306 * this)
307 */
308 static gchar *
_my_g_input_stream_read_line_safe(GInputStream * i,gsize * out_line_length,GCancellable * cancellable,GError ** error)309 _my_g_input_stream_read_line_safe (GInputStream *i,
310 gsize *out_line_length,
311 GCancellable *cancellable,
312 GError **error)
313 {
314 GString *str;
315 gchar c;
316 gssize num_read;
317 gboolean last_was_cr;
318
319 str = g_string_new (NULL);
320
321 last_was_cr = FALSE;
322 while (TRUE)
323 {
324 num_read = g_input_stream_read (i,
325 &c,
326 1,
327 cancellable,
328 error);
329 if (num_read == -1)
330 goto fail;
331 if (num_read == 0)
332 {
333 if (error != NULL && *error == NULL)
334 {
335 g_set_error_literal (error,
336 G_IO_ERROR,
337 G_IO_ERROR_FAILED,
338 _("Unexpected lack of content trying to (safely) read a line"));
339 }
340 goto fail;
341 }
342
343 g_string_append_c (str, (gint) c);
344 if (last_was_cr)
345 {
346 if (c == 0x0a)
347 {
348 g_assert (str->len >= 2);
349 g_string_set_size (str, str->len - 2);
350 goto out;
351 }
352 }
353 last_was_cr = (c == 0x0d);
354 }
355
356 out:
357 if (out_line_length != NULL)
358 *out_line_length = str->len;
359 return g_string_free (str, FALSE);
360
361 fail:
362 g_assert (error == NULL || *error != NULL);
363 g_string_free (str, TRUE);
364 return NULL;
365 }
366
367 /* ---------------------------------------------------------------------------------------------------- */
368
369 static gchar *
hexdecode(const gchar * str,gsize * out_len,GError ** error)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 *out_len = s->len;
403 ret = g_string_free (s, FALSE);
404 s = NULL;
405
406 out:
407 if (s != NULL)
408 {
409 *out_len = 0;
410 g_string_free (s, TRUE);
411 }
412 return ret;
413 }
414
415 /* ---------------------------------------------------------------------------------------------------- */
416
417 static GDBusAuthMechanism *
client_choose_mech_and_send_initial_response(GDBusAuth * auth,GCredentials * credentials_that_were_sent,const gchar * const * supported_auth_mechs,GPtrArray * attempted_auth_mechs,GDataOutputStream * dos,GCancellable * cancellable,GError ** error)418 client_choose_mech_and_send_initial_response (GDBusAuth *auth,
419 GCredentials *credentials_that_were_sent,
420 const gchar* const *supported_auth_mechs,
421 GPtrArray *attempted_auth_mechs,
422 GDataOutputStream *dos,
423 GCancellable *cancellable,
424 GError **error)
425 {
426 GDBusAuthMechanism *mech;
427 GType auth_mech_to_use_gtype;
428 guint n;
429 guint m;
430 gchar *initial_response;
431 gsize initial_response_len;
432 gchar *encoded;
433 gchar *s;
434
435 again:
436 mech = NULL;
437
438 debug_print ("CLIENT: Trying to choose mechanism");
439
440 /* find an authentication mechanism to try, if any */
441 auth_mech_to_use_gtype = (GType) 0;
442 for (n = 0; supported_auth_mechs[n] != NULL; n++)
443 {
444 gboolean attempted_already;
445 attempted_already = FALSE;
446 for (m = 0; m < attempted_auth_mechs->len; m++)
447 {
448 if (g_strcmp0 (supported_auth_mechs[n], attempted_auth_mechs->pdata[m]) == 0)
449 {
450 attempted_already = TRUE;
451 break;
452 }
453 }
454 if (!attempted_already)
455 {
456 auth_mech_to_use_gtype = find_mech_by_name (auth, supported_auth_mechs[n]);
457 if (auth_mech_to_use_gtype != (GType) 0)
458 break;
459 }
460 }
461
462 if (auth_mech_to_use_gtype == (GType) 0)
463 {
464 guint n;
465 gchar *available;
466 GString *tried_str;
467
468 debug_print ("CLIENT: Exhausted all available mechanisms");
469
470 available = g_strjoinv (", ", (gchar **) supported_auth_mechs);
471
472 tried_str = g_string_new (NULL);
473 for (n = 0; n < attempted_auth_mechs->len; n++)
474 {
475 if (n > 0)
476 g_string_append (tried_str, ", ");
477 g_string_append (tried_str, attempted_auth_mechs->pdata[n]);
478 }
479 g_set_error (error,
480 G_IO_ERROR,
481 G_IO_ERROR_FAILED,
482 _("Exhausted all available authentication mechanisms (tried: %s) (available: %s)"),
483 tried_str->str,
484 available);
485 g_string_free (tried_str, TRUE);
486 g_free (available);
487 goto out;
488 }
489
490 /* OK, decided on a mechanism - let's do this thing */
491 mech = g_object_new (auth_mech_to_use_gtype,
492 "stream", auth->priv->stream,
493 "credentials", credentials_that_were_sent,
494 NULL);
495 debug_print ("CLIENT: Trying mechanism '%s'", _g_dbus_auth_mechanism_get_name (auth_mech_to_use_gtype));
496 g_ptr_array_add (attempted_auth_mechs, (gpointer) _g_dbus_auth_mechanism_get_name (auth_mech_to_use_gtype));
497
498 /* the auth mechanism may not be supported
499 * (for example, EXTERNAL only works if credentials were exchanged)
500 */
501 if (!_g_dbus_auth_mechanism_is_supported (mech))
502 {
503 debug_print ("CLIENT: Mechanism '%s' says it is not supported", _g_dbus_auth_mechanism_get_name (auth_mech_to_use_gtype));
504 g_object_unref (mech);
505 mech = NULL;
506 goto again;
507 }
508
509 initial_response_len = 0;
510 initial_response = _g_dbus_auth_mechanism_client_initiate (mech,
511 &initial_response_len);
512 #if 0
513 g_printerr ("using auth mechanism with name '%s' of type '%s' with initial response '%s'\n",
514 _g_dbus_auth_mechanism_get_name (auth_mech_to_use_gtype),
515 g_type_name (G_TYPE_FROM_INSTANCE (mech)),
516 initial_response);
517 #endif
518 if (initial_response != NULL)
519 {
520 //g_printerr ("initial_response = '%s'\n", initial_response);
521 encoded = _g_dbus_hexencode (initial_response, initial_response_len);
522 s = g_strdup_printf ("AUTH %s %s\r\n",
523 _g_dbus_auth_mechanism_get_name (auth_mech_to_use_gtype),
524 encoded);
525 g_free (initial_response);
526 g_free (encoded);
527 }
528 else
529 {
530 s = g_strdup_printf ("AUTH %s\r\n", _g_dbus_auth_mechanism_get_name (auth_mech_to_use_gtype));
531 }
532 debug_print ("CLIENT: writing '%s'", s);
533 if (!g_data_output_stream_put_string (dos, s, cancellable, error))
534 {
535 g_object_unref (mech);
536 mech = NULL;
537 g_free (s);
538 goto out;
539 }
540 g_free (s);
541
542 out:
543 return mech;
544 }
545
546
547 /* ---------------------------------------------------------------------------------------------------- */
548
549 typedef enum
550 {
551 CLIENT_STATE_WAITING_FOR_DATA,
552 CLIENT_STATE_WAITING_FOR_OK,
553 CLIENT_STATE_WAITING_FOR_REJECT,
554 CLIENT_STATE_WAITING_FOR_AGREE_UNIX_FD
555 } ClientState;
556
557 gchar *
_g_dbus_auth_run_client(GDBusAuth * auth,GDBusAuthObserver * observer,GDBusCapabilityFlags offered_capabilities,GDBusCapabilityFlags * out_negotiated_capabilities,GCancellable * cancellable,GError ** error)558 _g_dbus_auth_run_client (GDBusAuth *auth,
559 GDBusAuthObserver *observer,
560 GDBusCapabilityFlags offered_capabilities,
561 GDBusCapabilityFlags *out_negotiated_capabilities,
562 GCancellable *cancellable,
563 GError **error)
564 {
565 gchar *s;
566 GDataInputStream *dis;
567 GDataOutputStream *dos;
568 GCredentials *credentials;
569 gchar *ret_guid;
570 gchar *line;
571 gsize line_length;
572 gchar **supported_auth_mechs;
573 GPtrArray *attempted_auth_mechs;
574 GDBusAuthMechanism *mech;
575 ClientState state;
576 GDBusCapabilityFlags negotiated_capabilities;
577
578 debug_print ("CLIENT: initiating");
579
580 _g_dbus_auth_add_mechs (auth, observer);
581
582 ret_guid = NULL;
583 supported_auth_mechs = NULL;
584 attempted_auth_mechs = g_ptr_array_new ();
585 mech = NULL;
586 negotiated_capabilities = 0;
587 credentials = NULL;
588
589 dis = G_DATA_INPUT_STREAM (g_data_input_stream_new (g_io_stream_get_input_stream (auth->priv->stream)));
590 dos = G_DATA_OUTPUT_STREAM (g_data_output_stream_new (g_io_stream_get_output_stream (auth->priv->stream)));
591 g_filter_input_stream_set_close_base_stream (G_FILTER_INPUT_STREAM (dis), FALSE);
592 g_filter_output_stream_set_close_base_stream (G_FILTER_OUTPUT_STREAM (dos), FALSE);
593
594 g_data_input_stream_set_newline_type (dis, G_DATA_STREAM_NEWLINE_TYPE_CR_LF);
595
596 #ifdef G_OS_UNIX
597 if (G_IS_UNIX_CONNECTION (auth->priv->stream))
598 {
599 credentials = g_credentials_new ();
600 if (!g_unix_connection_send_credentials (G_UNIX_CONNECTION (auth->priv->stream),
601 cancellable,
602 error))
603 goto out;
604 }
605 else
606 {
607 if (!g_data_output_stream_put_byte (dos, '\0', cancellable, error))
608 goto out;
609 }
610 #else
611 if (!g_data_output_stream_put_byte (dos, '\0', cancellable, error))
612 goto out;
613 #endif
614
615 if (credentials != NULL)
616 {
617 if (G_UNLIKELY (_g_dbus_debug_authentication ()))
618 {
619 s = g_credentials_to_string (credentials);
620 debug_print ("CLIENT: sent credentials '%s'", s);
621 g_free (s);
622 }
623 }
624 else
625 {
626 debug_print ("CLIENT: didn't send any credentials");
627 }
628
629 /* TODO: to reduce roundtrips, try to pick an auth mechanism to start with */
630
631 /* Get list of supported authentication mechanisms */
632 s = "AUTH\r\n";
633 debug_print ("CLIENT: writing '%s'", s);
634 if (!g_data_output_stream_put_string (dos, s, cancellable, error))
635 goto out;
636 state = CLIENT_STATE_WAITING_FOR_REJECT;
637
638 while (TRUE)
639 {
640 switch (state)
641 {
642 case CLIENT_STATE_WAITING_FOR_REJECT:
643 debug_print ("CLIENT: WaitingForReject");
644 line = _my_g_data_input_stream_read_line (dis, &line_length, cancellable, error);
645 if (line == NULL)
646 goto out;
647 debug_print ("CLIENT: WaitingForReject, read '%s'", line);
648
649 choose_mechanism:
650 if (!g_str_has_prefix (line, "REJECTED "))
651 {
652 g_set_error (error,
653 G_IO_ERROR,
654 G_IO_ERROR_FAILED,
655 "In WaitingForReject: Expected 'REJECTED am1 am2 ... amN', got '%s'",
656 line);
657 g_free (line);
658 goto out;
659 }
660 if (supported_auth_mechs == NULL)
661 {
662 supported_auth_mechs = g_strsplit (line + sizeof ("REJECTED ") - 1, " ", 0);
663 #if 0
664 for (n = 0; supported_auth_mechs != NULL && supported_auth_mechs[n] != NULL; n++)
665 g_printerr ("supported_auth_mechs[%d] = '%s'\n", n, supported_auth_mechs[n]);
666 #endif
667 }
668 g_free (line);
669 mech = client_choose_mech_and_send_initial_response (auth,
670 credentials,
671 (const gchar* const *) supported_auth_mechs,
672 attempted_auth_mechs,
673 dos,
674 cancellable,
675 error);
676 if (mech == NULL)
677 goto out;
678 if (_g_dbus_auth_mechanism_client_get_state (mech) == G_DBUS_AUTH_MECHANISM_STATE_WAITING_FOR_DATA)
679 state = CLIENT_STATE_WAITING_FOR_DATA;
680 else
681 state = CLIENT_STATE_WAITING_FOR_OK;
682 break;
683
684 case CLIENT_STATE_WAITING_FOR_OK:
685 debug_print ("CLIENT: WaitingForOK");
686 line = _my_g_data_input_stream_read_line (dis, &line_length, cancellable, error);
687 if (line == NULL)
688 goto out;
689 debug_print ("CLIENT: WaitingForOK, read '%s'", line);
690 if (g_str_has_prefix (line, "OK "))
691 {
692 if (!g_dbus_is_guid (line + 3))
693 {
694 g_set_error (error,
695 G_IO_ERROR,
696 G_IO_ERROR_FAILED,
697 "Invalid OK response '%s'",
698 line);
699 g_free (line);
700 goto out;
701 }
702 ret_guid = g_strdup (line + 3);
703 g_free (line);
704
705 if (offered_capabilities & G_DBUS_CAPABILITY_FLAGS_UNIX_FD_PASSING)
706 {
707 s = "NEGOTIATE_UNIX_FD\r\n";
708 debug_print ("CLIENT: writing '%s'", s);
709 if (!g_data_output_stream_put_string (dos, s, cancellable, error))
710 goto out;
711 state = CLIENT_STATE_WAITING_FOR_AGREE_UNIX_FD;
712 }
713 else
714 {
715 s = "BEGIN\r\n";
716 debug_print ("CLIENT: writing '%s'", s);
717 if (!g_data_output_stream_put_string (dos, s, cancellable, error))
718 goto out;
719 /* and we're done! */
720 goto out;
721 }
722 }
723 else if (g_str_has_prefix (line, "REJECTED "))
724 {
725 goto choose_mechanism;
726 }
727 else
728 {
729 /* TODO: handle other valid responses */
730 g_set_error (error,
731 G_IO_ERROR,
732 G_IO_ERROR_FAILED,
733 "In WaitingForOk: unexpected response '%s'",
734 line);
735 g_free (line);
736 goto out;
737 }
738 break;
739
740 case CLIENT_STATE_WAITING_FOR_AGREE_UNIX_FD:
741 debug_print ("CLIENT: WaitingForAgreeUnixFD");
742 line = _my_g_data_input_stream_read_line (dis, &line_length, cancellable, error);
743 if (line == NULL)
744 goto out;
745 debug_print ("CLIENT: WaitingForAgreeUnixFD, read='%s'", line);
746 if (g_strcmp0 (line, "AGREE_UNIX_FD") == 0)
747 {
748 g_free (line);
749 negotiated_capabilities |= G_DBUS_CAPABILITY_FLAGS_UNIX_FD_PASSING;
750 s = "BEGIN\r\n";
751 debug_print ("CLIENT: writing '%s'", s);
752 if (!g_data_output_stream_put_string (dos, s, cancellable, error))
753 goto out;
754 /* and we're done! */
755 goto out;
756 }
757 else if (g_str_has_prefix (line, "ERROR") && (line[5] == 0 || g_ascii_isspace (line[5])))
758 {
759 //g_strstrip (line + 5); g_debug ("bah, no unix_fd: '%s'", line + 5);
760 g_free (line);
761 s = "BEGIN\r\n";
762 debug_print ("CLIENT: writing '%s'", s);
763 if (!g_data_output_stream_put_string (dos, s, cancellable, error))
764 goto out;
765 /* and we're done! */
766 goto out;
767 }
768 else
769 {
770 /* TODO: handle other valid responses */
771 g_set_error (error,
772 G_IO_ERROR,
773 G_IO_ERROR_FAILED,
774 "In WaitingForAgreeUnixFd: unexpected response '%s'",
775 line);
776 g_free (line);
777 goto out;
778 }
779 break;
780
781 case CLIENT_STATE_WAITING_FOR_DATA:
782 debug_print ("CLIENT: WaitingForData");
783 line = _my_g_data_input_stream_read_line (dis, &line_length, cancellable, error);
784 if (line == NULL)
785 goto out;
786 debug_print ("CLIENT: WaitingForData, read='%s'", line);
787 if (g_str_has_prefix (line, "DATA "))
788 {
789 gchar *encoded;
790 gchar *decoded_data;
791 gsize decoded_data_len = 0;
792
793 encoded = g_strdup (line + 5);
794 g_free (line);
795 g_strstrip (encoded);
796 decoded_data = hexdecode (encoded, &decoded_data_len, error);
797 g_free (encoded);
798 if (decoded_data == NULL)
799 {
800 g_prefix_error (error, "DATA response is malformed: ");
801 /* invalid encoding, disconnect! */
802 goto out;
803 }
804 _g_dbus_auth_mechanism_client_data_receive (mech, decoded_data, decoded_data_len);
805 g_free (decoded_data);
806
807 if (_g_dbus_auth_mechanism_client_get_state (mech) == G_DBUS_AUTH_MECHANISM_STATE_HAVE_DATA_TO_SEND)
808 {
809 gchar *data;
810 gsize data_len;
811 gchar *encoded_data;
812 data = _g_dbus_auth_mechanism_client_data_send (mech, &data_len);
813 encoded_data = _g_dbus_hexencode (data, data_len);
814 s = g_strdup_printf ("DATA %s\r\n", encoded_data);
815 g_free (encoded_data);
816 g_free (data);
817 debug_print ("CLIENT: writing '%s'", s);
818 if (!g_data_output_stream_put_string (dos, s, cancellable, error))
819 {
820 g_free (s);
821 goto out;
822 }
823 g_free (s);
824 }
825 state = CLIENT_STATE_WAITING_FOR_OK;
826 }
827 else if (g_str_has_prefix (line, "REJECTED "))
828 {
829 /* could be the chosen authentication method just doesn't work. Try
830 * another one...
831 */
832 goto choose_mechanism;
833 }
834 else
835 {
836 g_set_error (error,
837 G_IO_ERROR,
838 G_IO_ERROR_FAILED,
839 "In WaitingForData: unexpected response '%s'",
840 line);
841 g_free (line);
842 goto out;
843 }
844 break;
845
846 default:
847 g_assert_not_reached ();
848 break;
849 }
850
851 }; /* main authentication client loop */
852
853 out:
854 if (mech != NULL)
855 g_object_unref (mech);
856 g_ptr_array_unref (attempted_auth_mechs);
857 g_strfreev (supported_auth_mechs);
858 g_object_unref (dis);
859 g_object_unref (dos);
860
861 /* ensure return value is NULL if error is set */
862 if (error != NULL && *error != NULL)
863 {
864 g_free (ret_guid);
865 ret_guid = NULL;
866 }
867
868 if (ret_guid != NULL)
869 {
870 if (out_negotiated_capabilities != NULL)
871 *out_negotiated_capabilities = negotiated_capabilities;
872 }
873
874 if (credentials != NULL)
875 g_object_unref (credentials);
876
877 debug_print ("CLIENT: Done, authenticated=%d", ret_guid != NULL);
878
879 return ret_guid;
880 }
881
882 /* ---------------------------------------------------------------------------------------------------- */
883
884 static gchar *
get_auth_mechanisms(GDBusAuth * auth,gboolean allow_anonymous,const gchar * prefix,const gchar * suffix,const gchar * separator)885 get_auth_mechanisms (GDBusAuth *auth,
886 gboolean allow_anonymous,
887 const gchar *prefix,
888 const gchar *suffix,
889 const gchar *separator)
890 {
891 GList *l;
892 GString *str;
893 gboolean need_sep;
894
895 str = g_string_new (prefix);
896 need_sep = FALSE;
897 for (l = auth->priv->available_mechanisms; l != NULL; l = l->next)
898 {
899 Mechanism *m = l->data;
900
901 if (!allow_anonymous && g_strcmp0 (m->name, "ANONYMOUS") == 0)
902 continue;
903
904 if (need_sep)
905 g_string_append (str, separator);
906 g_string_append (str, m->name);
907 need_sep = TRUE;
908 }
909
910 g_string_append (str, suffix);
911 return g_string_free (str, FALSE);
912 }
913
914
915 typedef enum
916 {
917 SERVER_STATE_WAITING_FOR_AUTH,
918 SERVER_STATE_WAITING_FOR_DATA,
919 SERVER_STATE_WAITING_FOR_BEGIN
920 } ServerState;
921
922 gboolean
_g_dbus_auth_run_server(GDBusAuth * auth,GDBusAuthObserver * observer,const gchar * guid,gboolean allow_anonymous,gboolean require_same_user,GDBusCapabilityFlags offered_capabilities,GDBusCapabilityFlags * out_negotiated_capabilities,GCredentials ** out_received_credentials,GCancellable * cancellable,GError ** error)923 _g_dbus_auth_run_server (GDBusAuth *auth,
924 GDBusAuthObserver *observer,
925 const gchar *guid,
926 gboolean allow_anonymous,
927 gboolean require_same_user,
928 GDBusCapabilityFlags offered_capabilities,
929 GDBusCapabilityFlags *out_negotiated_capabilities,
930 GCredentials **out_received_credentials,
931 GCancellable *cancellable,
932 GError **error)
933 {
934 gboolean ret;
935 ServerState state;
936 GDataInputStream *dis;
937 GDataOutputStream *dos;
938 GError *local_error;
939 gchar *line;
940 gsize line_length;
941 GDBusAuthMechanism *mech;
942 gchar *s;
943 GDBusCapabilityFlags negotiated_capabilities;
944 GCredentials *credentials;
945 GCredentials *own_credentials = NULL;
946
947 debug_print ("SERVER: initiating");
948
949 _g_dbus_auth_add_mechs (auth, observer);
950
951 ret = FALSE;
952 dis = NULL;
953 dos = NULL;
954 mech = NULL;
955 negotiated_capabilities = 0;
956 credentials = NULL;
957
958 if (!g_dbus_is_guid (guid))
959 {
960 g_set_error (error,
961 G_IO_ERROR,
962 G_IO_ERROR_FAILED,
963 "The given guid '%s' is not valid",
964 guid);
965 goto out;
966 }
967
968 dis = G_DATA_INPUT_STREAM (g_data_input_stream_new (g_io_stream_get_input_stream (auth->priv->stream)));
969 dos = G_DATA_OUTPUT_STREAM (g_data_output_stream_new (g_io_stream_get_output_stream (auth->priv->stream)));
970 g_filter_input_stream_set_close_base_stream (G_FILTER_INPUT_STREAM (dis), FALSE);
971 g_filter_output_stream_set_close_base_stream (G_FILTER_OUTPUT_STREAM (dos), FALSE);
972
973 g_data_input_stream_set_newline_type (dis, G_DATA_STREAM_NEWLINE_TYPE_CR_LF);
974
975 /* read the NUL-byte, possibly with credentials attached */
976 #ifdef G_OS_UNIX
977 #ifndef G_CREDENTIALS_PREFER_MESSAGE_PASSING
978 if (G_IS_SOCKET_CONNECTION (auth->priv->stream))
979 {
980 GSocket *sock = g_socket_connection_get_socket (G_SOCKET_CONNECTION (auth->priv->stream));
981
982 local_error = NULL;
983 credentials = g_socket_get_credentials (sock, &local_error);
984
985 if (credentials == NULL && !g_error_matches (local_error, G_IO_ERROR, G_IO_ERROR_NOT_SUPPORTED))
986 {
987 g_propagate_error (error, local_error);
988 goto out;
989 }
990 else
991 {
992 /* Clear the error indicator, so we can retry with
993 * g_unix_connection_receive_credentials() if necessary */
994 g_clear_error (&local_error);
995 }
996 }
997 #endif
998
999 if (credentials == NULL && G_IS_UNIX_CONNECTION (auth->priv->stream))
1000 {
1001 local_error = NULL;
1002 credentials = g_unix_connection_receive_credentials (G_UNIX_CONNECTION (auth->priv->stream),
1003 cancellable,
1004 &local_error);
1005 if (credentials == NULL && !g_error_matches (local_error, G_IO_ERROR, G_IO_ERROR_NOT_SUPPORTED))
1006 {
1007 g_propagate_error (error, local_error);
1008 goto out;
1009 }
1010 }
1011 else
1012 {
1013 local_error = NULL;
1014 (void)g_data_input_stream_read_byte (dis, cancellable, &local_error);
1015 if (local_error != NULL)
1016 {
1017 g_propagate_error (error, local_error);
1018 goto out;
1019 }
1020 }
1021 #else
1022 local_error = NULL;
1023 (void)g_data_input_stream_read_byte (dis, cancellable, &local_error);
1024 if (local_error != NULL)
1025 {
1026 g_propagate_error (error, local_error);
1027 goto out;
1028 }
1029 #endif
1030 if (credentials != NULL)
1031 {
1032 if (G_UNLIKELY (_g_dbus_debug_authentication ()))
1033 {
1034 s = g_credentials_to_string (credentials);
1035 debug_print ("SERVER: received credentials '%s'", s);
1036 g_free (s);
1037 }
1038 }
1039 else
1040 {
1041 debug_print ("SERVER: didn't receive any credentials");
1042 }
1043
1044 own_credentials = g_credentials_new ();
1045
1046 state = SERVER_STATE_WAITING_FOR_AUTH;
1047 while (TRUE)
1048 {
1049 switch (state)
1050 {
1051 case SERVER_STATE_WAITING_FOR_AUTH:
1052 debug_print ("SERVER: WaitingForAuth");
1053 line = _my_g_data_input_stream_read_line (dis, &line_length, cancellable, error);
1054 debug_print ("SERVER: WaitingForAuth, read '%s'", line);
1055 if (line == NULL)
1056 goto out;
1057 if (g_strcmp0 (line, "AUTH") == 0)
1058 {
1059 s = get_auth_mechanisms (auth, allow_anonymous, "REJECTED ", "\r\n", " ");
1060 debug_print ("SERVER: writing '%s'", s);
1061 if (!g_data_output_stream_put_string (dos, s, cancellable, error))
1062 {
1063 g_free (s);
1064 g_free (line);
1065 goto out;
1066 }
1067 g_free (s);
1068 g_free (line);
1069 }
1070 else if (g_str_has_prefix (line, "AUTH "))
1071 {
1072 gchar **tokens;
1073 const gchar *encoded;
1074 const gchar *mech_name;
1075 GType auth_mech_to_use_gtype;
1076
1077 tokens = g_strsplit (line, " ", 0);
1078
1079 switch (g_strv_length (tokens))
1080 {
1081 case 2:
1082 /* no initial response */
1083 mech_name = tokens[1];
1084 encoded = NULL;
1085 break;
1086
1087 case 3:
1088 /* initial response */
1089 mech_name = tokens[1];
1090 encoded = tokens[2];
1091 break;
1092
1093 default:
1094 g_set_error (error,
1095 G_IO_ERROR,
1096 G_IO_ERROR_FAILED,
1097 "Unexpected line '%s' while in WaitingForAuth state",
1098 line);
1099 g_strfreev (tokens);
1100 g_free (line);
1101 goto out;
1102 }
1103
1104 g_free (line);
1105
1106 /* TODO: record that the client has attempted to use this mechanism */
1107 //g_debug ("client is trying '%s'", mech_name);
1108
1109 auth_mech_to_use_gtype = find_mech_by_name (auth, mech_name);
1110 if ((auth_mech_to_use_gtype == (GType) 0) ||
1111 (!allow_anonymous && g_strcmp0 (mech_name, "ANONYMOUS") == 0))
1112 {
1113 /* We don't support this auth mechanism */
1114 g_strfreev (tokens);
1115 s = get_auth_mechanisms (auth, allow_anonymous, "REJECTED ", "\r\n", " ");
1116 debug_print ("SERVER: writing '%s'", s);
1117 if (!g_data_output_stream_put_string (dos, s, cancellable, error))
1118 {
1119 g_free (s);
1120 goto out;
1121 }
1122 g_free (s);
1123
1124 /* stay in WAITING FOR AUTH */
1125 state = SERVER_STATE_WAITING_FOR_AUTH;
1126 }
1127 else
1128 {
1129 gchar *initial_response;
1130 gsize initial_response_len;
1131
1132 g_clear_object (&mech);
1133 mech = g_object_new (auth_mech_to_use_gtype,
1134 "stream", auth->priv->stream,
1135 "credentials", credentials,
1136 NULL);
1137
1138 initial_response = NULL;
1139 initial_response_len = 0;
1140 if (encoded != NULL)
1141 {
1142 initial_response = hexdecode (encoded, &initial_response_len, error);
1143 if (initial_response == NULL)
1144 {
1145 g_prefix_error (error, "Initial response is malformed: ");
1146 /* invalid encoding, disconnect! */
1147 g_strfreev (tokens);
1148 goto out;
1149 }
1150 }
1151
1152 _g_dbus_auth_mechanism_server_initiate (mech,
1153 initial_response,
1154 initial_response_len);
1155 g_free (initial_response);
1156 g_strfreev (tokens);
1157
1158 change_state:
1159 switch (_g_dbus_auth_mechanism_server_get_state (mech))
1160 {
1161 case G_DBUS_AUTH_MECHANISM_STATE_ACCEPTED:
1162 if (require_same_user &&
1163 (credentials == NULL ||
1164 !g_credentials_is_same_user (credentials, own_credentials, NULL)))
1165 {
1166 /* disconnect */
1167 g_set_error_literal (error,
1168 G_IO_ERROR,
1169 G_IO_ERROR_FAILED,
1170 _("User IDs must be the same for peer and server"));
1171 goto out;
1172 }
1173 else if (observer != NULL &&
1174 !g_dbus_auth_observer_authorize_authenticated_peer (observer,
1175 auth->priv->stream,
1176 credentials))
1177 {
1178 /* disconnect */
1179 g_set_error_literal (error,
1180 G_IO_ERROR,
1181 G_IO_ERROR_FAILED,
1182 _("Cancelled via GDBusAuthObserver::authorize-authenticated-peer"));
1183 goto out;
1184 }
1185 else
1186 {
1187 s = g_strdup_printf ("OK %s\r\n", guid);
1188 debug_print ("SERVER: writing '%s'", s);
1189 if (!g_data_output_stream_put_string (dos, s, cancellable, error))
1190 {
1191 g_free (s);
1192 goto out;
1193 }
1194 g_free (s);
1195 state = SERVER_STATE_WAITING_FOR_BEGIN;
1196 }
1197 break;
1198
1199 case G_DBUS_AUTH_MECHANISM_STATE_REJECTED:
1200 s = get_auth_mechanisms (auth, allow_anonymous, "REJECTED ", "\r\n", " ");
1201 debug_print ("SERVER: writing '%s'", s);
1202 if (!g_data_output_stream_put_string (dos, s, cancellable, error))
1203 {
1204 g_free (s);
1205 goto out;
1206 }
1207 g_free (s);
1208 state = SERVER_STATE_WAITING_FOR_AUTH;
1209 break;
1210
1211 case G_DBUS_AUTH_MECHANISM_STATE_WAITING_FOR_DATA:
1212 state = SERVER_STATE_WAITING_FOR_DATA;
1213 break;
1214
1215 case G_DBUS_AUTH_MECHANISM_STATE_HAVE_DATA_TO_SEND:
1216 {
1217 gchar *data;
1218 gsize data_len;
1219
1220 data = _g_dbus_auth_mechanism_server_data_send (mech, &data_len);
1221 if (data != NULL)
1222 {
1223 gchar *encoded_data;
1224
1225 encoded_data = _g_dbus_hexencode (data, data_len);
1226 s = g_strdup_printf ("DATA %s\r\n", encoded_data);
1227 g_free (encoded_data);
1228 g_free (data);
1229
1230 debug_print ("SERVER: writing '%s'", s);
1231 if (!g_data_output_stream_put_string (dos, s, cancellable, error))
1232 {
1233 g_free (s);
1234 goto out;
1235 }
1236 g_free (s);
1237 }
1238 }
1239 goto change_state;
1240 break;
1241
1242 default:
1243 /* TODO */
1244 g_assert_not_reached ();
1245 break;
1246 }
1247 }
1248 }
1249 else
1250 {
1251 g_set_error (error,
1252 G_IO_ERROR,
1253 G_IO_ERROR_FAILED,
1254 "Unexpected line '%s' while in WaitingForAuth state",
1255 line);
1256 g_free (line);
1257 goto out;
1258 }
1259 break;
1260
1261 case SERVER_STATE_WAITING_FOR_DATA:
1262 debug_print ("SERVER: WaitingForData");
1263 line = _my_g_data_input_stream_read_line (dis, &line_length, cancellable, error);
1264 debug_print ("SERVER: WaitingForData, read '%s'", line);
1265 if (line == NULL)
1266 goto out;
1267 if (g_str_has_prefix (line, "DATA "))
1268 {
1269 gchar *encoded;
1270 gchar *decoded_data;
1271 gsize decoded_data_len = 0;
1272
1273 encoded = g_strdup (line + 5);
1274 g_free (line);
1275 g_strstrip (encoded);
1276 decoded_data = hexdecode (encoded, &decoded_data_len, error);
1277 g_free (encoded);
1278 if (decoded_data == NULL)
1279 {
1280 g_prefix_error (error, "DATA response is malformed: ");
1281 /* invalid encoding, disconnect! */
1282 goto out;
1283 }
1284 _g_dbus_auth_mechanism_server_data_receive (mech, decoded_data, decoded_data_len);
1285 g_free (decoded_data);
1286 /* oh man, this goto-crap is so ugly.. really need to rewrite the state machine */
1287 goto change_state;
1288 }
1289 else
1290 {
1291 g_set_error (error,
1292 G_IO_ERROR,
1293 G_IO_ERROR_FAILED,
1294 "Unexpected line '%s' while in WaitingForData state",
1295 line);
1296 g_free (line);
1297 }
1298 goto out;
1299
1300 case SERVER_STATE_WAITING_FOR_BEGIN:
1301 debug_print ("SERVER: WaitingForBegin");
1302 /* Use extremely slow (but reliable) line reader - this basically
1303 * does a recvfrom() system call per character
1304 *
1305 * (the problem with using GDataInputStream's read_line is that because of
1306 * buffering it might start reading into the first D-Bus message that
1307 * appears after "BEGIN\r\n"....)
1308 */
1309 line = _my_g_input_stream_read_line_safe (g_io_stream_get_input_stream (auth->priv->stream),
1310 &line_length,
1311 cancellable,
1312 error);
1313 if (line == NULL)
1314 goto out;
1315 debug_print ("SERVER: WaitingForBegin, read '%s'", line);
1316 if (g_strcmp0 (line, "BEGIN") == 0)
1317 {
1318 /* YAY, done! */
1319 ret = TRUE;
1320 g_free (line);
1321 goto out;
1322 }
1323 else if (g_strcmp0 (line, "NEGOTIATE_UNIX_FD") == 0)
1324 {
1325 g_free (line);
1326 if (offered_capabilities & G_DBUS_CAPABILITY_FLAGS_UNIX_FD_PASSING)
1327 {
1328 negotiated_capabilities |= G_DBUS_CAPABILITY_FLAGS_UNIX_FD_PASSING;
1329 s = "AGREE_UNIX_FD\r\n";
1330 debug_print ("SERVER: writing '%s'", s);
1331 if (!g_data_output_stream_put_string (dos, s, cancellable, error))
1332 goto out;
1333 }
1334 else
1335 {
1336 s = "ERROR \"fd passing not offered\"\r\n";
1337 debug_print ("SERVER: writing '%s'", s);
1338 if (!g_data_output_stream_put_string (dos, s, cancellable, error))
1339 goto out;
1340 }
1341 }
1342 else
1343 {
1344 g_debug ("Unexpected line '%s' while in WaitingForBegin state", line);
1345 g_free (line);
1346 s = "ERROR \"Unknown Command\"\r\n";
1347 debug_print ("SERVER: writing '%s'", s);
1348 if (!g_data_output_stream_put_string (dos, s, cancellable, error))
1349 goto out;
1350 }
1351 break;
1352
1353 default:
1354 g_assert_not_reached ();
1355 break;
1356 }
1357 }
1358
1359
1360 g_set_error_literal (error,
1361 G_IO_ERROR,
1362 G_IO_ERROR_FAILED,
1363 "Not implemented (server)");
1364
1365 out:
1366 g_clear_object (&mech);
1367 g_clear_object (&dis);
1368 g_clear_object (&dos);
1369 g_clear_object (&own_credentials);
1370
1371 /* ensure return value is FALSE if error is set */
1372 if (error != NULL && *error != NULL)
1373 {
1374 ret = FALSE;
1375 }
1376
1377 if (ret)
1378 {
1379 if (out_negotiated_capabilities != NULL)
1380 *out_negotiated_capabilities = negotiated_capabilities;
1381 if (out_received_credentials != NULL)
1382 *out_received_credentials = credentials != NULL ? g_object_ref (credentials) : NULL;
1383 }
1384
1385 if (credentials != NULL)
1386 g_object_unref (credentials);
1387
1388 debug_print ("SERVER: Done, authenticated=%d", ret);
1389
1390 return ret;
1391 }
1392
1393 /* ---------------------------------------------------------------------------------------------------- */
1394