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sasl.c @ 5ff4618

Last change on this file since 5ff4618 was 5ebff60, checked in by dequis <dx@…>, at 2015-02-20T22:50:54Z

Reindent everything to K&R style with tabs

Used uncrustify, with the configuration file in ./doc/uncrustify.cfg

Commit author set to "Indent <please@…>" so that it's easier to
skip while doing git blame.

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Line
1	/***************************************************************************\
2	* *
3	* BitlBee - An IRC to IM gateway *
4	* Jabber module - SASL authentication *
5	* *
6	* Copyright 2006-2012 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
50	xt_status sasl_pkt_mechanisms(struct xt_node *node, gpointer data)
51	{
52	struct im_connection *ic = data;
53	struct jabber_data *jd = ic->proto_data;
54	struct xt_node c, reply;
55	char *s;
56	int sup_plain = 0, sup_digest = 0, sup_gtalk = 0, sup_fb = 0;
57	int want_oauth = FALSE;
58	GString *mechs;
59
60	if (!sasl_supported(ic)) {
61	/* Should abort this now, since we should already be doing
62	IQ authentication. Strange things happen when you try
63	to do both... */
64	imcb_log(ic,
65	"XMPP 1.0 non-compliant server seems to support SASL, please report this as a BitlBee bug!");
66	return XT_HANDLED;
67	}
68
69	s = xt_find_attr(node, "xmlns");
70	if (!s \|\| strcmp(s, XMLNS_SASL) != 0) {
71	imcb_log(ic, "Stream error while authenticating");
72	imc_logout(ic, FALSE);
73	return XT_ABORT;
74	}
75
76	want_oauth = set_getbool(&ic->acc->set, "oauth");
77
78	mechs = g_string_new("");
79	c = node->children;
80	while ((c = xt_find_node(c, "mechanism"))) {
81	if (c->text && g_strcasecmp(c->text, "PLAIN") == 0) {
82	sup_plain = 1;
83	} else if (c->text && g_strcasecmp(c->text, "DIGEST-MD5") == 0) {
84	sup_digest = 1;
85	} else if (c->text && g_strcasecmp(c->text, "X-OAUTH2") == 0) {
86	sup_gtalk = 1;
87	} else if (c->text && g_strcasecmp(c->text, "X-FACEBOOK-PLATFORM") == 0) {
88	sup_fb = 1;
89	}
90
91	if (c->text) {
92	g_string_append_printf(mechs, " %s", c->text);
93	}
94
95	c = c->next;
96	}
97
98	if (!want_oauth && !sup_plain && !sup_digest) {
99	if (!sup_gtalk && !sup_fb) {
100	imcb_error(ic, "This server requires OAuth "
101	"(supported schemes:%s)", mechs->str);
102	} else {
103	imcb_error(ic, "BitlBee does not support any of the offered SASL "
104	"authentication schemes:%s", mechs->str);
105	}
106	imc_logout(ic, FALSE);
107	g_string_free(mechs, TRUE);
108	return XT_ABORT;
109	}
110	g_string_free(mechs, TRUE);
111
112	reply = xt_new_node("auth", NULL, NULL);
113	xt_add_attr(reply, "xmlns", XMLNS_SASL);
114
115	if (sup_gtalk && want_oauth) {
116	int len;
117
118	/* X-OAUTH2 is, not the standard OAuth2 SASL/XMPP implementation.
119	It's currently used by GTalk and vaguely documented on
120	http://code.google.com/apis/cloudprint/docs/rawxmpp.html . */
121	xt_add_attr(reply, "mechanism", "X-OAUTH2");
122
123	len = strlen(jd->username) + strlen(jd->oauth2_access_token) + 2;
124	s = g_malloc(len + 1);
125	s[0] = 0;
126	strcpy(s + 1, jd->username);
127	strcpy(s + 2 + strlen(jd->username), jd->oauth2_access_token);
128	reply->text = base64_encode((unsigned char *) s, len);
129	reply->text_len = strlen(reply->text);
130	g_free(s);
131	} else if (sup_fb && want_oauth) {
132	xt_add_attr(reply, "mechanism", "X-FACEBOOK-PLATFORM");
133	jd->flags \|= JFLAG_SASL_FB;
134	} else if (want_oauth) {
135	imcb_error(ic, "OAuth requested, but not supported by server");
136	imc_logout(ic, FALSE);
137	xt_free_node(reply);
138	return XT_ABORT;
139	} else if (sup_digest) {
140	xt_add_attr(reply, "mechanism", "DIGEST-MD5");
141
142	/* The rest will be done later, when we receive a <challenge/>. */
143	} else if (sup_plain) {
144	int len;
145
146	xt_add_attr(reply, "mechanism", "PLAIN");
147
148	/* With SASL PLAIN in XMPP, the text should be b64(\0user\0pass) */
149	len = strlen(jd->username) + strlen(ic->acc->pass) + 2;
150	s = g_malloc(len + 1);
151	s[0] = 0;
152	strcpy(s + 1, jd->username);
153	strcpy(s + 2 + strlen(jd->username), ic->acc->pass);
154	reply->text = base64_encode((unsigned char *) s, len);
155	reply->text_len = strlen(reply->text);
156	g_free(s);
157	}
158
159	if (reply && !jabber_write_packet(ic, reply)) {
160	xt_free_node(reply);
161	return XT_ABORT;
162	}
163	xt_free_node(reply);
164
165	/* To prevent classic authentication from happening. */
166	jd->flags \|= JFLAG_STREAM_STARTED;
167
168	return XT_HANDLED;
169	}
170
171	/* Non-static function, but not mentioned in jabber.h because it's for internal
172	use, just that the unittest should be able to reach it... */
173	char sasl_get_part(char data, char *field)
174	{
175	int i, len;
176
177	len = strlen(field);
178
179	while (g_ascii_isspace(data) \|\| data == ',') {
180	data++;
181	}
182
183	if (g_strncasecmp(data, field, len) == 0 && data[len] == '=') {
184	i = strlen(field) + 1;
185	} else {
186	for (i = 0; data[i]; i++) {
187	/* If we have a ", skip until it's closed again. */
188	if (data[i] == '"') {
189	i++;
190	while (data[i] != '"' \|\| data[i - 1] == '\\') {
191	i++;
192	}
193	}
194
195	/* If we got a comma, we got a new field. Check it,
196	find the next key after it. */
197	if (data[i] == ',') {
198	while (g_ascii_isspace(data[i]) \|\| data[i] == ',') {
199	i++;
200	}
201
202	if (g_strncasecmp(data + i, field, len) == 0 &&
203	data[i + len] == '=') {
204	i += len + 1;
205	break;
206	}
207	}
208	}
209	}
210
211	if (data[i] == '"') {
212	int j;
213	char *ret;
214
215	i++;
216	len = 0;
217	while (data[i + len] != '"' \|\| data[i + len - 1] == '\\') {
218	len++;
219	}
220
221	ret = g_strndup(data + i, len);
222	for (i = j = 0; ret[i]; i++) {
223	if (ret[i] == '\\') {
224	ret[j++] = ret[++i];
225	} else {
226	ret[j++] = ret[i];
227	}
228	}
229	ret[j] = 0;
230
231	return ret;
232	} else if (data[i]) {
233	len = 0;
234	while (data[i + len] && data[i + len] != ',') {
235	len++;
236	}
237
238	return g_strndup(data + i, len);
239	} else {
240	return NULL;
241	}
242	}
243
244	xt_status sasl_pkt_challenge(struct xt_node *node, gpointer data)
245	{
246	struct im_connection *ic = data;
247	struct jabber_data *jd = ic->proto_data;
248	struct xt_node *reply_pkt = NULL;
249	char nonce = NULL, realm = NULL, *cnonce = NULL;
250	unsigned char cnonce_bin[30];
251	char *digest_uri = NULL;
252	char *dec = NULL;
253	char s = NULL, reply = NULL;
254	xt_status ret = XT_ABORT;
255
256	if (node->text_len == 0) {
257	goto error;
258	}
259
260	dec = frombase64(node->text);
261
262	if (jd->flags & JFLAG_SASL_FB) {
263	/* New-style Facebook OAauth2 support. Instead of sending a refresh
264	token, they just send an access token that should never expire. */
265	GSList p_in = NULL, p_out = NULL;
266	char time[33];
267
268	oauth_params_parse(&p_in, dec);
269	oauth_params_add(&p_out, "nonce", oauth_params_get(&p_in, "nonce"));
270	oauth_params_add(&p_out, "method", oauth_params_get(&p_in, "method"));
271	oauth_params_free(&p_in);
272
273	g_snprintf(time, sizeof(time), "%lld", (long long) (gettime() * 1000));
274	oauth_params_add(&p_out, "call_id", time);
275	oauth_params_add(&p_out, "api_key", oauth2_service_facebook.consumer_key);
276	oauth_params_add(&p_out, "v", "1.0");
277	oauth_params_add(&p_out, "format", "XML");
278	oauth_params_add(&p_out, "access_token", jd->oauth2_access_token);
279
280	reply = oauth_params_string(p_out);
281	oauth_params_free(&p_out);
282	} else if (!(s = sasl_get_part(dec, "rspauth"))) {
283	/* See RFC 2831 for for information. */
284	md5_state_t A1, A2, H;
285	md5_byte_t A1r[16], A2r[16], Hr[16];
286	char A1h[33], A2h[33], Hh[33];
287	int i;
288
289	nonce = sasl_get_part(dec, "nonce");
290	realm = sasl_get_part(dec, "realm");
291
292	if (!nonce) {
293	goto error;
294	}
295
296	/* Jabber.Org considers the realm part optional and doesn't
297	specify one. Oh well, actually they're right, but still,
298	don't know if this is right... */
299	if (!realm) {
300	realm = g_strdup(jd->server);
301	}
302
303	random_bytes(cnonce_bin, sizeof(cnonce_bin));
304	cnonce = base64_encode(cnonce_bin, sizeof(cnonce_bin));
305	digest_uri = g_strdup_printf("%s/%s", "xmpp", jd->server);
306
307	/* Generate the MD5 hash of username:realm:password,
308	I decided to call it H. */
309	md5_init(&H);
310	s = g_strdup_printf("%s:%s:%s", jd->username, realm, ic->acc->pass);
311	md5_append(&H, (unsigned char *) s, strlen(s));
312	g_free(s);
313	md5_finish(&H, Hr);
314
315	/* Now generate the hex. MD5 hash of H:nonce:cnonce, called A1. */
316	md5_init(&A1);
317	s = g_strdup_printf(":%s:%s", nonce, cnonce);
318	md5_append(&A1, Hr, 16);
319	md5_append(&A1, (unsigned char *) s, strlen(s));
320	g_free(s);
321	md5_finish(&A1, A1r);
322	for (i = 0; i < 16; i++) {
323	sprintf(A1h + i * 2, "%02x", A1r[i]);
324	}
325
326	/* A2... */
327	md5_init(&A2);
328	s = g_strdup_printf("%s:%s", "AUTHENTICATE", digest_uri);
329	md5_append(&A2, (unsigned char *) s, strlen(s));
330	g_free(s);
331	md5_finish(&A2, A2r);
332	for (i = 0; i < 16; i++) {
333	sprintf(A2h + i * 2, "%02x", A2r[i]);
334	}
335
336	/* Final result: A1:nonce:00000001:cnonce:auth:A2. Let's reuse H for it. */
337	md5_init(&H);
338	s = g_strdup_printf("%s:%s:%s:%s:%s:%s", A1h, nonce, "00000001", cnonce, "auth", A2h);
339	md5_append(&H, (unsigned char *) s, strlen(s));
340	g_free(s);
341	md5_finish(&H, Hr);
342	for (i = 0; i < 16; i++) {
343	sprintf(Hh + i * 2, "%02x", Hr[i]);
344	}
345
346	/* Now build the SASL response string: */
347	reply = g_strdup_printf("username=\"%s\",realm=\"%s\",nonce=\"%s\",cnonce=\"%s\","
348	"nc=%08x,qop=auth,digest-uri=\"%s\",response=%s,charset=%s",
349	jd->username, realm, nonce, cnonce, 1, digest_uri, Hh, "utf-8");
350	} else {
351	/* We found rspauth, but don't really care... */
352	g_free(s);
353	}
354
355	s = reply ? tobase64(reply) : NULL;
356	reply_pkt = xt_new_node("response", s, NULL);
357	xt_add_attr(reply_pkt, "xmlns", XMLNS_SASL);
358
359	if (!jabber_write_packet(ic, reply_pkt)) {
360	goto silent_error;
361	}
362
363	ret = XT_HANDLED;
364	goto silent_error;
365
366	error:
367	imcb_error(ic, "Incorrect SASL challenge received");
368	imc_logout(ic, FALSE);
369
370	silent_error:
371	g_free(digest_uri);
372	g_free(cnonce);
373	g_free(nonce);
374	g_free(reply);
375	g_free(realm);
376	g_free(dec);
377	g_free(s);
378	xt_free_node(reply_pkt);
379
380	return ret;
381	}
382
383	xt_status sasl_pkt_result(struct xt_node *node, gpointer data)
384	{
385	struct im_connection *ic = data;
386	struct jabber_data *jd = ic->proto_data;
387	char *s;
388
389	s = xt_find_attr(node, "xmlns");
390	if (!s \|\| strcmp(s, XMLNS_SASL) != 0) {
391	imcb_log(ic, "Stream error while authenticating");
392	imc_logout(ic, FALSE);
393	return XT_ABORT;
394	}
395
396	if (strcmp(node->name, "success") == 0) {
397	imcb_log(ic, "Authentication finished");
398	jd->flags \|= JFLAG_AUTHENTICATED \| JFLAG_STREAM_RESTART;
399	} else if (strcmp(node->name, "failure") == 0) {
400	imcb_error(ic, "Authentication failure");
401	imc_logout(ic, FALSE);
402	return XT_ABORT;
403	}
404
405	return XT_HANDLED;
406	}
407
408	/* This one is needed to judge if we'll do authentication using IQ or SASL.
409	It's done by checking if the <stream:stream> from the server has a
410	version attribute. I don't know if this is the right way though... */
411	gboolean sasl_supported(struct im_connection *ic)
412	{
413	struct jabber_data *jd = ic->proto_data;
414
415	return (jd->xt && jd->xt->root && xt_find_attr(jd->xt->root, "version")) != 0;
416	}
417
418	void sasl_oauth2_init(struct im_connection *ic)
419	{
420	struct jabber_data *jd = ic->proto_data;
421	char msg, url;
422
423	imcb_log(ic, "Starting OAuth authentication");
424
425	/* Temporary contact, just used to receive the OAuth response. */
426	imcb_add_buddy(ic, JABBER_OAUTH_HANDLE, NULL);
427	url = oauth2_url(jd->oauth2_service);
428	msg = g_strdup_printf("Open this URL in your browser to authenticate: %s", url);
429	imcb_buddy_msg(ic, JABBER_OAUTH_HANDLE, msg, 0, 0);
430	imcb_buddy_msg(ic, JABBER_OAUTH_HANDLE, "Respond to this message with the returned "
431	"authorization token.", 0, 0);
432
433	g_free(msg);
434	g_free(url);
435	}
436
437	static gboolean sasl_oauth2_remove_contact(gpointer data, gint fd, b_input_condition cond)
438	{
439	struct im_connection *ic = data;
440
441	if (g_slist_find(jabber_connections, ic)) {
442	imcb_remove_buddy(ic, JABBER_OAUTH_HANDLE, NULL);
443	}
444	return FALSE;
445	}
446
447	static void sasl_oauth2_got_token(gpointer data, const char access_token, const char refresh_token,
448	const char *error);
449
450	int sasl_oauth2_get_refresh_token(struct im_connection ic, const char msg)
451	{
452	struct jabber_data *jd = ic->proto_data;
453	char *code;
454	int ret;
455
456	imcb_log(ic, "Requesting OAuth access token");
457
458	/* Don't do it here because the caller may get confused if the contact
459	we're currently sending a message to is deleted. */
460	b_timeout_add(1, sasl_oauth2_remove_contact, ic);
461
462	code = g_strdup(msg);
463	g_strstrip(code);
464	ret = oauth2_access_token(jd->oauth2_service, OAUTH2_AUTH_CODE,
465	code, sasl_oauth2_got_token, ic);
466
467	g_free(code);
468	return ret;
469	}
470
471	int sasl_oauth2_refresh(struct im_connection ic, const char refresh_token)
472	{
473	struct jabber_data *jd = ic->proto_data;
474
475	return oauth2_access_token(jd->oauth2_service, OAUTH2_AUTH_REFRESH,
476	refresh_token, sasl_oauth2_got_token, ic);
477	}
478
479	static void sasl_oauth2_got_token(gpointer data, const char access_token, const char refresh_token, const char *error)
480	{
481	struct im_connection *ic = data;
482	struct jabber_data *jd;
483	GSList *auth = NULL;
484
485	if (g_slist_find(jabber_connections, ic) == NULL) {
486	return;
487	}
488
489	jd = ic->proto_data;
490
491	if (access_token == NULL) {
492	imcb_error(ic, "OAuth failure (%s)", error);
493	imc_logout(ic, TRUE);
494	return;
495	}
496
497	oauth_params_parse(&auth, ic->acc->pass);
498	if (refresh_token) {
499	oauth_params_set(&auth, "refresh_token", refresh_token);
500	}
501	if (access_token) {
502	oauth_params_set(&auth, "access_token", access_token);
503	}
504
505	g_free(ic->acc->pass);
506	ic->acc->pass = oauth_params_string(auth);
507	oauth_params_free(&auth);
508
509	g_free(jd->oauth2_access_token);
510	jd->oauth2_access_token = g_strdup(access_token);
511
512	jabber_connect(ic);
513	}

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source: protocols/jabber/sasl.c @ 5ff4618

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