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source: protocols/jabber/sasl.c @ 7d4ffc2

Last change on this file since 7d4ffc2 was 644b808, checked in by Wilmer van der Gaast <wilmer@…>, at 2011-12-26T10:50:34Z
A few more minor cleanups before merging this into mainline.
Property mode set to `100644`
File size: 15.7 KB

Line
1	/***************************************************************************\
2	* *
3	* BitlBee - An IRC to IM gateway *
4	* Jabber module - SASL authentication *
5	* *
6	* Copyright 2006 Wilmer van der Gaast <wilmer@gaast.net> *
7	* *
8	* This program is free software; you can redistribute it and/or modify *
9	* it under the terms of the GNU General Public License as published by *
10	* the Free Software Foundation; either version 2 of the License, or *
11	* (at your option) any later version. *
12	* *
13	* This program is distributed in the hope that it will be useful, *
14	* but WITHOUT ANY WARRANTY; without even the implied warranty of *
15	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the *
16	* GNU General Public License for more details. *
17	* *
18	* You should have received a copy of the GNU General Public License along *
19	* with this program; if not, write to the Free Software Foundation, Inc., *
20	* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. *
21	* *
22	\***************************************************************************/
23
24	#include <ctype.h>
25
26	#include "jabber.h"
27	#include "base64.h"
28	#include "oauth2.h"
29	#include "oauth.h"
30
31	const struct oauth2_service oauth2_service_google =
32	{
33	"https://accounts.google.com/o/oauth2/auth",
34	"https://accounts.google.com/o/oauth2/token",
35	"urn:ietf:wg:oauth:2.0:oob",
36	"https://www.googleapis.com/auth/googletalk",
37	"783993391592.apps.googleusercontent.com",
38	"6C-Zgf7Tr7gEQTPlBhMUgo7R",
39	};
40	const struct oauth2_service oauth2_service_facebook =
41	{
42	"https://www.facebook.com/dialog/oauth",
43	"https://graph.facebook.com/oauth/access_token",
44	"http://www.bitlbee.org/main.php/Facebook/oauth2.html",
45	"offline_access,xmpp_login",
46	"126828914005625",
47	"4b100f0f244d620bf3f15f8b217d4c32",
48	};
49	const struct oauth2_service oauth2_service_mslive =
50	{
51	"https://oauth.live.com/authorize",
52	"https://oauth.live.com/token",
53	"http://www.bitlbee.org/main.php/Messenger/oauth2.html",
54	"wl.offline_access%20wl.messenger",
55	"000000004C06FCD1",
56	"IRKlBPzJJAWcY-TbZjiTEJu9tn7XCFaV",
57	};
58
59	xt_status sasl_pkt_mechanisms( struct xt_node *node, gpointer data )
60	{
61	struct im_connection *ic = data;
62	struct jabber_data *jd = ic->proto_data;
63	struct xt_node c, reply;
64	char *s;
65	int sup_plain = 0, sup_digest = 0, sup_gtalk = 0, sup_fb = 0, sup_ms = 0;
66	int want_oauth = FALSE;
67	GString *mechs;
68
69	if( !sasl_supported( ic ) )
70	{
71	/* Should abort this now, since we should already be doing
72	IQ authentication. Strange things happen when you try
73	to do both... */
74	imcb_log( ic, "XMPP 1.0 non-compliant server seems to support SASL, please report this as a BitlBee bug!" );
75	return XT_HANDLED;
76	}
77
78	s = xt_find_attr( node, "xmlns" );
79	if( !s \|\| strcmp( s, XMLNS_SASL ) != 0 )
80	{
81	imcb_log( ic, "Stream error while authenticating" );
82	imc_logout( ic, FALSE );
83	return XT_ABORT;
84	}
85
86	mechs = g_string_new( "" );
87	c = node->children;
88	while( ( c = xt_find_node( c, "mechanism" ) ) )
89	{
90	if( c->text && g_strcasecmp( c->text, "PLAIN" ) == 0 )
91	sup_plain = 1;
92	else if( c->text && g_strcasecmp( c->text, "DIGEST-MD5" ) == 0 )
93	sup_digest = 1;
94	else if( c->text && g_strcasecmp( c->text, "X-OAUTH2" ) == 0 )
95	sup_gtalk = 1;
96	else if( c->text && g_strcasecmp( c->text, "X-FACEBOOK-PLATFORM" ) == 0 )
97	sup_fb = 1;
98	else if( c->text && g_strcasecmp( c->text, "X-MESSENGER-OAUTH2" ) == 0 )
99	sup_ms = 1;
100
101	if( c->text )
102	g_string_append_printf( mechs, " %s", c->text );
103
104	c = c->next;
105	}
106
107	if( !sup_plain && !sup_digest )
108	{
109	if( !sup_gtalk && !sup_fb && !sup_ms )
110	imcb_error( ic, "This server requires OAuth "
111	"(supported schemes:%s)", mechs->str );
112	else
113	imcb_error( ic, "BitlBee does not support any of the offered SASL "
114	"authentication schemes:%s", mechs->str );
115	imc_logout( ic, FALSE );
116	g_string_free( mechs, TRUE );
117	return XT_ABORT;
118	}
119	g_string_free( mechs, TRUE );
120
121	reply = xt_new_node( "auth", NULL, NULL );
122	xt_add_attr( reply, "xmlns", XMLNS_SASL );
123	want_oauth = set_getbool( &ic->acc->set, "oauth" );
124
125	if( sup_gtalk && want_oauth )
126	{
127	int len;
128
129	/* X-OAUTH2 is, not the standard OAuth2 SASL/XMPP implementation.
130	It's currently used by GTalk and vaguely documented on
131	http://code.google.com/apis/cloudprint/docs/rawxmpp.html . */
132	xt_add_attr( reply, "mechanism", "X-OAUTH2" );
133
134	len = strlen( jd->username ) + strlen( jd->oauth2_access_token ) + 2;
135	s = g_malloc( len + 1 );
136	s[0] = 0;
137	strcpy( s + 1, jd->username );
138	strcpy( s + 2 + strlen( jd->username ), jd->oauth2_access_token );
139	reply->text = base64_encode( (unsigned char *)s, len );
140	reply->text_len = strlen( reply->text );
141	g_free( s );
142	}
143	else if( sup_ms && want_oauth )
144	{
145	xt_add_attr( reply, "mechanism", "X-MESSENGER-OAUTH2" );
146	reply->text = g_strdup( jd->oauth2_access_token );
147	reply->text_len = strlen( jd->oauth2_access_token );
148	}
149	else if( sup_fb && want_oauth )
150	{
151	xt_add_attr( reply, "mechanism", "X-FACEBOOK-PLATFORM" );
152	jd->flags \|= JFLAG_SASL_FB;
153	}
154	else if( want_oauth )
155	{
156	imcb_error( ic, "OAuth requested, but not supported by server" );
157	imc_logout( ic, FALSE );
158	xt_free_node( reply );
159	return XT_ABORT;
160	}
161	else if( sup_digest )
162	{
163	xt_add_attr( reply, "mechanism", "DIGEST-MD5" );
164
165	/* The rest will be done later, when we receive a <challenge/>. */
166	}
167	else if( sup_plain )
168	{
169	int len;
170
171	xt_add_attr( reply, "mechanism", "PLAIN" );
172
173	/* With SASL PLAIN in XMPP, the text should be b64(\0user\0pass) */
174	len = strlen( jd->username ) + strlen( ic->acc->pass ) + 2;
175	s = g_malloc( len + 1 );
176	s[0] = 0;
177	strcpy( s + 1, jd->username );
178	strcpy( s + 2 + strlen( jd->username ), ic->acc->pass );
179	reply->text = base64_encode( (unsigned char *)s, len );
180	reply->text_len = strlen( reply->text );
181	g_free( s );
182	}
183
184	if( reply && !jabber_write_packet( ic, reply ) )
185	{
186	xt_free_node( reply );
187	return XT_ABORT;
188	}
189	xt_free_node( reply );
190
191	/* To prevent classic authentication from happening. */
192	jd->flags \|= JFLAG_STREAM_STARTED;
193
194	return XT_HANDLED;
195	}
196
197	/* Non-static function, but not mentioned in jabber.h because it's for internal
198	use, just that the unittest should be able to reach it... */
199	char sasl_get_part( char data, char *field )
200	{
201	int i, len;
202
203	len = strlen( field );
204
205	while( isspace( data ) \|\| data == ',' )
206	data ++;
207
208	if( g_strncasecmp( data, field, len ) == 0 && data[len] == '=' )
209	{
210	i = strlen( field ) + 1;
211	}
212	else
213	{
214	for( i = 0; data[i]; i ++ )
215	{
216	/* If we have a ", skip until it's closed again. */
217	if( data[i] == '"' )
218	{
219	i ++;
220	while( data[i] != '"' \|\| data[i-1] == '\\' )
221	i ++;
222	}
223
224	/* If we got a comma, we got a new field. Check it,
225	find the next key after it. */
226	if( data[i] == ',' )
227	{
228	while( isspace( data[i] ) \|\| data[i] == ',' )
229	i ++;
230
231	if( g_strncasecmp( data + i, field, len ) == 0 &&
232	data[i+len] == '=' )
233	{
234	i += len + 1;
235	break;
236	}
237	}
238	}
239	}
240
241	if( data[i] == '"' )
242	{
243	int j;
244	char *ret;
245
246	i ++;
247	len = 0;
248	while( data[i+len] != '"' \|\| data[i+len-1] == '\\' )
249	len ++;
250
251	ret = g_strndup( data + i, len );
252	for( i = j = 0; ret[i]; i ++ )
253	{
254	if( ret[i] == '\\' )
255	{
256	ret[j++] = ret[++i];
257	}
258	else
259	{
260	ret[j++] = ret[i];
261	}
262	}
263	ret[j] = 0;
264
265	return ret;
266	}
267	else if( data[i] )
268	{
269	len = 0;
270	while( data[i+len] && data[i+len] != ',' )
271	len ++;
272
273	return g_strndup( data + i, len );
274	}
275	else
276	{
277	return NULL;
278	}
279	}
280
281	xt_status sasl_pkt_challenge( struct xt_node *node, gpointer data )
282	{
283	struct im_connection *ic = data;
284	struct jabber_data *jd = ic->proto_data;
285	struct xt_node *reply_pkt = NULL;
286	char nonce = NULL, realm = NULL, *cnonce = NULL;
287	unsigned char cnonce_bin[30];
288	char *digest_uri = NULL;
289	char *dec = NULL;
290	char s = NULL, reply = NULL;
291	xt_status ret = XT_ABORT;
292
293	if( node->text_len == 0 )
294	goto error;
295
296	dec = frombase64( node->text );
297
298	if( jd->flags & JFLAG_SASL_FB )
299	{
300	/* New-style Facebook OAauth2 support. Instead of sending a refresh
301	token, they just send an access token that should never expire. */
302	GSList p_in = NULL, p_out = NULL;
303	char time[33];
304
305	oauth_params_parse( &p_in, dec );
306	oauth_params_add( &p_out, "nonce", oauth_params_get( &p_in, "nonce" ) );
307	oauth_params_add( &p_out, "method", oauth_params_get( &p_in, "method" ) );
308	oauth_params_free( &p_in );
309
310	g_snprintf( time, sizeof( time ), "%lld", (long long) ( gettime() * 1000 ) );
311	oauth_params_add( &p_out, "call_id", time );
312	oauth_params_add( &p_out, "api_key", oauth2_service_facebook.consumer_key );
313	oauth_params_add( &p_out, "v", "1.0" );
314	oauth_params_add( &p_out, "format", "XML" );
315	oauth_params_add( &p_out, "access_token", jd->oauth2_access_token );
316
317	reply = oauth_params_string( p_out );
318	oauth_params_free( &p_out );
319	}
320	else if( !( s = sasl_get_part( dec, "rspauth" ) ) )
321	{
322	/* See RFC 2831 for for information. */
323	md5_state_t A1, A2, H;
324	md5_byte_t A1r[16], A2r[16], Hr[16];
325	char A1h[33], A2h[33], Hh[33];
326	int i;
327
328	nonce = sasl_get_part( dec, "nonce" );
329	realm = sasl_get_part( dec, "realm" );
330
331	if( !nonce )
332	goto error;
333
334	/* Jabber.Org considers the realm part optional and doesn't
335	specify one. Oh well, actually they're right, but still,
336	don't know if this is right... */
337	if( !realm )
338	realm = g_strdup( jd->server );
339
340	random_bytes( cnonce_bin, sizeof( cnonce_bin ) );
341	cnonce = base64_encode( cnonce_bin, sizeof( cnonce_bin ) );
342	digest_uri = g_strdup_printf( "%s/%s", "xmpp", jd->server );
343
344	/* Generate the MD5 hash of username:realm:password,
345	I decided to call it H. */
346	md5_init( &H );
347	s = g_strdup_printf( "%s:%s:%s", jd->username, realm, ic->acc->pass );
348	md5_append( &H, (unsigned char *) s, strlen( s ) );
349	g_free( s );
350	md5_finish( &H, Hr );
351
352	/* Now generate the hex. MD5 hash of H:nonce:cnonce, called A1. */
353	md5_init( &A1 );
354	s = g_strdup_printf( ":%s:%s", nonce, cnonce );
355	md5_append( &A1, Hr, 16 );
356	md5_append( &A1, (unsigned char *) s, strlen( s ) );
357	g_free( s );
358	md5_finish( &A1, A1r );
359	for( i = 0; i < 16; i ++ )
360	sprintf( A1h + i * 2, "%02x", A1r[i] );
361
362	/* A2... */
363	md5_init( &A2 );
364	s = g_strdup_printf( "%s:%s", "AUTHENTICATE", digest_uri );
365	md5_append( &A2, (unsigned char *) s, strlen( s ) );
366	g_free( s );
367	md5_finish( &A2, A2r );
368	for( i = 0; i < 16; i ++ )
369	sprintf( A2h + i * 2, "%02x", A2r[i] );
370
371	/* Final result: A1:nonce:00000001:cnonce:auth:A2. Let's reuse H for it. */
372	md5_init( &H );
373	s = g_strdup_printf( "%s:%s:%s:%s:%s:%s", A1h, nonce, "00000001", cnonce, "auth", A2h );
374	md5_append( &H, (unsigned char *) s, strlen( s ) );
375	g_free( s );
376	md5_finish( &H, Hr );
377	for( i = 0; i < 16; i ++ )
378	sprintf( Hh + i * 2, "%02x", Hr[i] );
379
380	/* Now build the SASL response string: */
381	reply = g_strdup_printf( "username=\"%s\",realm=\"%s\",nonce=\"%s\",cnonce=\"%s\","
382	"nc=%08x,qop=auth,digest-uri=\"%s\",response=%s,charset=%s",
383	jd->username, realm, nonce, cnonce, 1, digest_uri, Hh, "utf-8" );
384	}
385	else
386	{
387	/* We found rspauth, but don't really care... */
388	}
389
390	s = reply ? tobase64( reply ) : NULL;
391	reply_pkt = xt_new_node( "response", s, NULL );
392	xt_add_attr( reply_pkt, "xmlns", XMLNS_SASL );
393
394	if( !jabber_write_packet( ic, reply_pkt ) )
395	goto silent_error;
396
397	ret = XT_HANDLED;
398	goto silent_error;
399
400	error:
401	imcb_error( ic, "Incorrect SASL challenge received" );
402	imc_logout( ic, FALSE );
403
404	silent_error:
405	g_free( digest_uri );
406	g_free( cnonce );
407	g_free( nonce );
408	g_free( reply );
409	g_free( realm );
410	g_free( dec );
411	g_free( s );
412	xt_free_node( reply_pkt );
413
414	return ret;
415	}
416
417	xt_status sasl_pkt_result( struct xt_node *node, gpointer data )
418	{
419	struct im_connection *ic = data;
420	struct jabber_data *jd = ic->proto_data;
421	char *s;
422
423	s = xt_find_attr( node, "xmlns" );
424	if( !s \|\| strcmp( s, XMLNS_SASL ) != 0 )
425	{
426	imcb_log( ic, "Stream error while authenticating" );
427	imc_logout( ic, FALSE );
428	return XT_ABORT;
429	}
430
431	if( strcmp( node->name, "success" ) == 0 )
432	{
433	imcb_log( ic, "Authentication finished" );
434	jd->flags \|= JFLAG_AUTHENTICATED \| JFLAG_STREAM_RESTART;
435	}
436	else if( strcmp( node->name, "failure" ) == 0 )
437	{
438	imcb_error( ic, "Authentication failure" );
439	imc_logout( ic, FALSE );
440	return XT_ABORT;
441	}
442
443	return XT_HANDLED;
444	}
445
446	/* This one is needed to judge if we'll do authentication using IQ or SASL.
447	It's done by checking if the <stream:stream> from the server has a
448	version attribute. I don't know if this is the right way though... */
449	gboolean sasl_supported( struct im_connection *ic )
450	{
451	struct jabber_data *jd = ic->proto_data;
452
453	return ( jd->xt && jd->xt->root && xt_find_attr( jd->xt->root, "version" ) ) != 0;
454	}
455
456	void sasl_oauth2_init( struct im_connection *ic )
457	{
458	struct jabber_data *jd = ic->proto_data;
459	char msg, url;
460
461	imcb_log( ic, "Starting OAuth authentication" );
462
463	/* Temporary contact, just used to receive the OAuth response. */
464	imcb_add_buddy( ic, JABBER_OAUTH_HANDLE, NULL );
465	url = oauth2_url( jd->oauth2_service );
466	msg = g_strdup_printf( "Open this URL in your browser to authenticate: %s", url );
467	imcb_buddy_msg( ic, JABBER_OAUTH_HANDLE, msg, 0, 0 );
468	imcb_buddy_msg( ic, JABBER_OAUTH_HANDLE, "Respond to this message with the returned "
469	"authorization token.", 0, 0 );
470
471	g_free( msg );
472	g_free( url );
473	}
474
475	static gboolean sasl_oauth2_remove_contact( gpointer data, gint fd, b_input_condition cond )
476	{
477	struct im_connection *ic = data;
478	if( g_slist_find( jabber_connections, ic ) )
479	imcb_remove_buddy( ic, JABBER_OAUTH_HANDLE, NULL );
480	return FALSE;
481	}
482
483	static void sasl_oauth2_got_token( gpointer data, const char access_token, const char refresh_token );
484
485	int sasl_oauth2_get_refresh_token( struct im_connection ic, const char msg )
486	{
487	struct jabber_data *jd = ic->proto_data;
488	char *code;
489	int ret;
490
491	imcb_log( ic, "Requesting OAuth access token" );
492
493	/* Don't do it here because the caller may get confused if the contact
494	we're currently sending a message to is deleted. */
495	b_timeout_add( 1, sasl_oauth2_remove_contact, ic );
496
497	code = g_strdup( msg );
498	g_strstrip( code );
499	ret = oauth2_access_token( jd->oauth2_service, OAUTH2_AUTH_CODE,
500	code, sasl_oauth2_got_token, ic );
501
502	g_free( code );
503	return ret;
504	}
505
506	int sasl_oauth2_refresh( struct im_connection ic, const char refresh_token )
507	{
508	struct jabber_data *jd = ic->proto_data;
509
510	return oauth2_access_token( jd->oauth2_service, OAUTH2_AUTH_REFRESH,
511	refresh_token, sasl_oauth2_got_token, ic );
512	}
513
514	static void sasl_oauth2_got_token( gpointer data, const char access_token, const char refresh_token )
515	{
516	struct im_connection *ic = data;
517	struct jabber_data *jd;
518	GSList *auth = NULL;
519
520	if( g_slist_find( jabber_connections, ic ) == NULL )
521	return;
522
523	jd = ic->proto_data;
524
525	if( access_token == NULL )
526	{
527	imcb_error( ic, "OAuth failure (missing access token)" );
528	imc_logout( ic, TRUE );
529	return;
530	}
531
532	oauth_params_parse( &auth, ic->acc->pass );
533	if( refresh_token )
534	oauth_params_set( &auth, "refresh_token", refresh_token );
535	if( access_token )
536	oauth_params_set( &auth, "access_token", access_token );
537
538	g_free( ic->acc->pass );
539	ic->acc->pass = oauth_params_string( auth );
540	oauth_params_free( &auth );
541
542	g_free( jd->oauth2_access_token );
543	jd->oauth2_access_token = g_strdup( access_token );
544
545	jabber_connect( ic );
546	}

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