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source: protocols/jabber/sasl.c @ 87dddee

Last change on this file since 87dddee was 911d97a, checked in by Wilmer van der Gaast <wilmer@…>, at 2011-08-04T15:19:54Z

Error handling fixes.

Found one double free() bug causing troubles when a buddy_msg() handler takes
down the IM connection immediately.

Property mode set to 100644

File size: 14.5 KB

Rev	Line
[5997488]	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
[af97b23]	24	#include <ctype.h>
	25
[5997488]	26	#include "jabber.h"
	27	#include "base64.h"
[57b4525]	28	#include "oauth2.h"
[e1c926f]	29	#include "oauth.h"
[5997488]	30
	31	xt_status sasl_pkt_mechanisms( struct xt_node *node, gpointer data )
	32	{
[0da65d5]	33	struct im_connection *ic = data;
	34	struct jabber_data *jd = ic->proto_data;
[5997488]	35	struct xt_node c, reply;
	36	char *s;
[e1c926f]	37	int sup_plain = 0, sup_digest = 0, sup_oauth2 = 0, sup_fb = 0;
[5997488]	38
[0da65d5]	39	if( !sasl_supported( ic ) )
[8d74291]	40	{
	41	/* Should abort this now, since we should already be doing
	42	IQ authentication. Strange things happen when you try
	43	to do both... */
[84b045d]	44	imcb_log( ic, "XMPP 1.0 non-compliant server seems to support SASL, please report this as a BitlBee bug!" );
[8d74291]	45	return XT_HANDLED;
	46	}
	47
[5997488]	48	s = xt_find_attr( node, "xmlns" );
[47d3ac4]	49	if( !s \|\| strcmp( s, XMLNS_SASL ) != 0 )
[5997488]	50	{
[84b045d]	51	imcb_log( ic, "Stream error while authenticating" );
[c2fb3809]	52	imc_logout( ic, FALSE );
[5997488]	53	return XT_ABORT;
	54	}
	55
	56	c = node->children;
	57	while( ( c = xt_find_node( c, "mechanism" ) ) )
	58	{
	59	if( c->text && g_strcasecmp( c->text, "PLAIN" ) == 0 )
	60	sup_plain = 1;
	61	if( c->text && g_strcasecmp( c->text, "DIGEST-MD5" ) == 0 )
	62	sup_digest = 1;
[57b4525]	63	if( c->text && g_strcasecmp( c->text, "X-OAUTH2" ) == 0 )
	64	sup_oauth2 = 1;
[e1c926f]	65	if( c->text && g_strcasecmp( c->text, "X-FACEBOOK-PLATFORM" ) == 0 )
	66	sup_fb = 1;
[5997488]	67
	68	c = c->next;
	69	}
	70
	71	if( !sup_plain && !sup_digest )
	72	{
[84b045d]	73	imcb_error( ic, "No known SASL authentication schemes supported" );
[c2fb3809]	74	imc_logout( ic, FALSE );
[5997488]	75	return XT_ABORT;
	76	}
	77
	78	reply = xt_new_node( "auth", NULL, NULL );
[47d3ac4]	79	xt_add_attr( reply, "xmlns", XMLNS_SASL );
[5997488]	80
[4a5d885]	81	if( set_getbool( &ic->acc->set, "oauth" ) )
[57b4525]	82	{
[4a5d885]	83	int len;
	84
	85	if( !sup_oauth2 )
	86	{
	87	imcb_error( ic, "OAuth requested, but not supported by server" );
	88	imc_logout( ic, FALSE );
	89	xt_free_node( reply );
	90	return XT_ABORT;
	91	}
	92
	93	/* X-OAUTH2 is, not the standard OAuth2 SASL/XMPP implementation.
	94	It's currently used by GTalk and vaguely documented on
	95	http://code.google.com/apis/cloudprint/docs/rawxmpp.html . */
	96	xt_add_attr( reply, "mechanism", "X-OAUTH2" );
	97
	98	len = strlen( jd->username ) + strlen( jd->oauth2_access_token ) + 2;
	99	s = g_malloc( len + 1 );
	100	s[0] = 0;
	101	strcpy( s + 1, jd->username );
	102	strcpy( s + 2 + strlen( jd->username ), jd->oauth2_access_token );
	103	reply->text = base64_encode( (unsigned char *)s, len );
	104	reply->text_len = strlen( reply->text );
	105	g_free( s );
[57b4525]	106	}
[e1c926f]	107	else if( sup_fb && strstr( ic->acc->pass, "session_key=" ) )
	108	{
	109	xt_add_attr( reply, "mechanism", "X-FACEBOOK-PLATFORM" );
	110	jd->flags \|= JFLAG_SASL_FB;
	111	}
[57b4525]	112	else if( sup_digest )
[fe7a554]	113	{
	114	xt_add_attr( reply, "mechanism", "DIGEST-MD5" );
	115
	116	/* The rest will be done later, when we receive a <challenge/>. */
	117	}
	118	else if( sup_plain )
[5997488]	119	{
	120	int len;
	121
	122	xt_add_attr( reply, "mechanism", "PLAIN" );
	123
	124	/* With SASL PLAIN in XMPP, the text should be b64(\0user\0pass) */
[0da65d5]	125	len = strlen( jd->username ) + strlen( ic->acc->pass ) + 2;
[5997488]	126	s = g_malloc( len + 1 );
	127	s[0] = 0;
	128	strcpy( s + 1, jd->username );
[0da65d5]	129	strcpy( s + 2 + strlen( jd->username ), ic->acc->pass );
[3b6eadc]	130	reply->text = base64_encode( (unsigned char *)s, len );
[5997488]	131	reply->text_len = strlen( reply->text );
	132	g_free( s );
	133	}
	134
[57b4525]	135	if( reply && !jabber_write_packet( ic, reply ) )
[5997488]	136	{
	137	xt_free_node( reply );
	138	return XT_ABORT;
	139	}
	140	xt_free_node( reply );
	141
	142	/* To prevent classic authentication from happening. */
	143	jd->flags \|= JFLAG_STREAM_STARTED;
	144
	145	return XT_HANDLED;
	146	}
	147
[af97b23]	148	/* Non-static function, but not mentioned in jabber.h because it's for internal
	149	use, just that the unittest should be able to reach it... */
	150	char sasl_get_part( char data, char *field )
[d8e0484]	151	{
	152	int i, len;
	153
	154	len = strlen( field );
	155
[af97b23]	156	while( isspace( data ) \|\| data == ',' )
	157	data ++;
	158
[d8e0484]	159	if( g_strncasecmp( data, field, len ) == 0 && data[len] == '=' )
	160	{
	161	i = strlen( field ) + 1;
	162	}
	163	else
	164	{
	165	for( i = 0; data[i]; i ++ )
	166	{
	167	/* If we have a ", skip until it's closed again. */
	168	if( data[i] == '"' )
	169	{
	170	i ++;
	171	while( data[i] != '"' \|\| data[i-1] == '\\' )
	172	i ++;
	173	}
	174
[af97b23]	175	/* If we got a comma, we got a new field. Check it,
	176	find the next key after it. */
	177	if( data[i] == ',' )
[d8e0484]	178	{
[af97b23]	179	while( isspace( data[i] ) \|\| data[i] == ',' )
	180	i ++;
	181
	182	if( g_strncasecmp( data + i, field, len ) == 0 &&
	183	data[i+len] == '=' )
	184	{
	185	i += len + 1;
	186	break;
	187	}
[d8e0484]	188	}
	189	}
	190	}
	191
	192	if( data[i] == '"' )
	193	{
	194	int j;
	195	char *ret;
	196
	197	i ++;
	198	len = 0;
	199	while( data[i+len] != '"' \|\| data[i+len-1] == '\\' )
	200	len ++;
	201
	202	ret = g_strndup( data + i, len );
	203	for( i = j = 0; ret[i]; i ++ )
	204	{
	205	if( ret[i] == '\\' )
	206	{
	207	ret[j++] = ret[++i];
	208	}
	209	else
	210	{
	211	ret[j++] = ret[i];
	212	}
	213	}
	214	ret[j] = 0;
	215
	216	return ret;
	217	}
	218	else if( data[i] )
	219	{
	220	len = 0;
	221	while( data[i+len] && data[i+len] != ',' )
	222	len ++;
	223
	224	return g_strndup( data + i, len );
	225	}
	226	else
	227	{
	228	return NULL;
	229	}
	230	}
	231
[5997488]	232	xt_status sasl_pkt_challenge( struct xt_node *node, gpointer data )
	233	{
[0da65d5]	234	struct im_connection *ic = data;
	235	struct jabber_data *jd = ic->proto_data;
[f138bd2]	236	struct xt_node *reply_pkt = NULL;
[3b6eadc]	237	char nonce = NULL, realm = NULL, *cnonce = NULL;
	238	unsigned char cnonce_bin[30];
[d8e0484]	239	char *digest_uri = NULL;
	240	char *dec = NULL;
[f138bd2]	241	char s = NULL, reply = NULL;
[d8e0484]	242	xt_status ret = XT_ABORT;
	243
	244	if( node->text_len == 0 )
	245	goto error;
	246
	247	dec = frombase64( node->text );
	248
[e1c926f]	249	if( jd->flags & JFLAG_SASL_FB )
	250	{
[f138bd2]	251	/* Facebook proprietary authentication. Not as useful as it seemed, but
	252	the code's written now, may as well keep it..
	253
	254	Mechanism is described on http://developers.facebook.com/docs/chat/
	255	and in their Python module. It's all mostly useless because the tokens
	256	expire after 24h. */
[e1c926f]	257	GSList p_in = NULL, p_out = NULL, *p;
	258	md5_state_t md5;
[f138bd2]	259	char time[33], *token;
[e1c926f]	260	const char *secret;
	261
	262	oauth_params_parse( &p_in, dec );
	263	oauth_params_add( &p_out, "nonce", oauth_params_get( &p_in, "nonce" ) );
	264	oauth_params_add( &p_out, "method", oauth_params_get( &p_in, "method" ) );
	265	oauth_params_free( &p_in );
	266
	267	token = g_strdup( ic->acc->pass );
	268	oauth_params_parse( &p_in, token );
	269	g_free( token );
	270	oauth_params_add( &p_out, "session_key", oauth_params_get( &p_in, "session_key" ) );
	271
	272	g_snprintf( time, sizeof( time ), "%lld", (long long) ( gettime() * 1000 ) );
	273	oauth_params_add( &p_out, "call_id", time );
	274	oauth_params_add( &p_out, "api_key", oauth2_service_facebook.consumer_key );
	275	oauth_params_add( &p_out, "v", "1.0" );
	276	oauth_params_add( &p_out, "format", "XML" );
	277
	278	md5_init( &md5 );
	279	for( p = p_out; p; p = p->next )
	280	md5_append( &md5, p->data, strlen( p->data ) );
	281
	282	secret = oauth_params_get( &p_in, "secret" );
[f138bd2]	283	if( secret )
	284	md5_append( &md5, (unsigned char*) secret, strlen( secret ) );
[e1c926f]	285	md5_finish_ascii( &md5, time );
	286	oauth_params_add( &p_out, "sig", time );
	287
[f138bd2]	288	reply = oauth_params_string( p_out );
[e1c926f]	289	oauth_params_free( &p_out );
	290	oauth_params_free( &p_in );
	291	}
	292	else if( !( s = sasl_get_part( dec, "rspauth" ) ) )
[d8e0484]	293	{
	294	/* See RFC 2831 for for information. */
	295	md5_state_t A1, A2, H;
	296	md5_byte_t A1r[16], A2r[16], Hr[16];
	297	char A1h[33], A2h[33], Hh[33];
	298	int i;
	299
	300	nonce = sasl_get_part( dec, "nonce" );
	301	realm = sasl_get_part( dec, "realm" );
	302
[d9282b4]	303	if( !nonce )
[d8e0484]	304	goto error;
	305
[d9282b4]	306	/* Jabber.Org considers the realm part optional and doesn't
	307	specify one. Oh well, actually they're right, but still,
	308	don't know if this is right... */
	309	if( !realm )
	310	realm = g_strdup( jd->server );
	311
[3b6eadc]	312	random_bytes( cnonce_bin, sizeof( cnonce_bin ) );
[d8e0484]	313	cnonce = base64_encode( cnonce_bin, sizeof( cnonce_bin ) );
	314	digest_uri = g_strdup_printf( "%s/%s", "xmpp", jd->server );
	315
	316	/* Generate the MD5 hash of username:realm:password,
	317	I decided to call it H. */
	318	md5_init( &H );
[0da65d5]	319	s = g_strdup_printf( "%s:%s:%s", jd->username, realm, ic->acc->pass );
[d8e0484]	320	md5_append( &H, (unsigned char *) s, strlen( s ) );
	321	g_free( s );
	322	md5_finish( &H, Hr );
	323
	324	/* Now generate the hex. MD5 hash of H:nonce:cnonce, called A1. */
	325	md5_init( &A1 );
	326	s = g_strdup_printf( ":%s:%s", nonce, cnonce );
	327	md5_append( &A1, Hr, 16 );
	328	md5_append( &A1, (unsigned char *) s, strlen( s ) );
	329	g_free( s );
	330	md5_finish( &A1, A1r );
	331	for( i = 0; i < 16; i ++ )
	332	sprintf( A1h + i * 2, "%02x", A1r[i] );
	333
	334	/* A2... */
	335	md5_init( &A2 );
	336	s = g_strdup_printf( "%s:%s", "AUTHENTICATE", digest_uri );
	337	md5_append( &A2, (unsigned char *) s, strlen( s ) );
	338	g_free( s );
	339	md5_finish( &A2, A2r );
	340	for( i = 0; i < 16; i ++ )
	341	sprintf( A2h + i * 2, "%02x", A2r[i] );
	342
	343	/* Final result: A1:nonce:00000001:cnonce:auth:A2. Let's reuse H for it. */
	344	md5_init( &H );
	345	s = g_strdup_printf( "%s:%s:%s:%s:%s:%s", A1h, nonce, "00000001", cnonce, "auth", A2h );
	346	md5_append( &H, (unsigned char *) s, strlen( s ) );
	347	g_free( s );
	348	md5_finish( &H, Hr );
	349	for( i = 0; i < 16; i ++ )
	350	sprintf( Hh + i * 2, "%02x", Hr[i] );
	351
	352	/* Now build the SASL response string: */
[f138bd2]	353	reply = g_strdup_printf( "username=\"%s\",realm=\"%s\",nonce=\"%s\",cnonce=\"%s\","
	354	"nc=%08x,qop=auth,digest-uri=\"%s\",response=%s,charset=%s",
	355	jd->username, realm, nonce, cnonce, 1, digest_uri, Hh, "utf-8" );
[d8e0484]	356	}
	357	else
	358	{
	359	/* We found rspauth, but don't really care... */
	360	}
	361
[f138bd2]	362	s = reply ? tobase64( reply ) : NULL;
	363	reply_pkt = xt_new_node( "response", s, NULL );
	364	xt_add_attr( reply_pkt, "xmlns", XMLNS_SASL );
[d8e0484]	365
[f138bd2]	366	if( !jabber_write_packet( ic, reply_pkt ) )
[d8e0484]	367	goto silent_error;
	368
	369	ret = XT_HANDLED;
	370	goto silent_error;
	371
	372	error:
[84b045d]	373	imcb_error( ic, "Incorrect SASL challenge received" );
[c2fb3809]	374	imc_logout( ic, FALSE );
[d8e0484]	375
	376	silent_error:
	377	g_free( digest_uri );
	378	g_free( cnonce );
	379	g_free( nonce );
[f138bd2]	380	g_free( reply );
[d8e0484]	381	g_free( realm );
	382	g_free( dec );
	383	g_free( s );
[f138bd2]	384	xt_free_node( reply_pkt );
[d8e0484]	385
	386	return ret;
[5997488]	387	}
	388
	389	xt_status sasl_pkt_result( struct xt_node *node, gpointer data )
	390	{
[0da65d5]	391	struct im_connection *ic = data;
	392	struct jabber_data *jd = ic->proto_data;
[5997488]	393	char *s;
	394
	395	s = xt_find_attr( node, "xmlns" );
[47d3ac4]	396	if( !s \|\| strcmp( s, XMLNS_SASL ) != 0 )
[5997488]	397	{
[84b045d]	398	imcb_log( ic, "Stream error while authenticating" );
[c2fb3809]	399	imc_logout( ic, FALSE );
[5997488]	400	return XT_ABORT;
	401	}
	402
	403	if( strcmp( node->name, "success" ) == 0 )
	404	{
[84b045d]	405	imcb_log( ic, "Authentication finished" );
[5997488]	406	jd->flags \|= JFLAG_AUTHENTICATED \| JFLAG_STREAM_RESTART;
	407	}
	408	else if( strcmp( node->name, "failure" ) == 0 )
	409	{
[84b045d]	410	imcb_error( ic, "Authentication failure" );
[c2fb3809]	411	imc_logout( ic, FALSE );
[5997488]	412	return XT_ABORT;
	413	}
	414
	415	return XT_HANDLED;
	416	}
[8d74291]	417
	418	/* This one is needed to judge if we'll do authentication using IQ or SASL.
	419	It's done by checking if the <stream:stream> from the server has a
	420	version attribute. I don't know if this is the right way though... */
[0da65d5]	421	gboolean sasl_supported( struct im_connection *ic )
[8d74291]	422	{
[0da65d5]	423	struct jabber_data *jd = ic->proto_data;
[8d74291]	424
[ef5c185]	425	return ( jd->xt && jd->xt->root && xt_find_attr( jd->xt->root, "version" ) ) != 0;
[8d74291]	426	}
[4a5d885]	427
	428	void sasl_oauth2_init( struct im_connection *ic )
	429	{
	430	char msg, url;
	431
	432	imcb_log( ic, "Starting OAuth authentication" );
	433
	434	/* Temporary contact, just used to receive the OAuth response. */
	435	imcb_add_buddy( ic, "jabber_oauth", NULL );
	436	url = oauth2_url( &oauth2_service_google,
	437	"https://www.googleapis.com/auth/googletalk" );
	438	msg = g_strdup_printf( "Open this URL in your browser to authenticate: %s", url );
	439	imcb_buddy_msg( ic, "jabber_oauth", msg, 0, 0 );
	440	imcb_buddy_msg( ic, "jabber_oauth", "Respond to this message with the returned "
	441	"authorization token.", 0, 0 );
	442
	443	g_free( msg );
	444	g_free( url );
	445	}
	446
	447	static gboolean sasl_oauth2_remove_contact( gpointer data, gint fd, b_input_condition cond )
	448	{
	449	struct im_connection *ic = data;
[911d97a]	450	if( g_slist_find( jabber_connections, ic ) )
	451	imcb_remove_buddy( ic, "jabber_oauth", NULL );
[4a5d885]	452	return FALSE;
	453	}
	454
	455	static void sasl_oauth2_got_token( gpointer data, const char access_token, const char refresh_token );
	456
	457	int sasl_oauth2_get_refresh_token( struct im_connection ic, const char msg )
	458	{
	459	char *code;
	460	int ret;
	461
	462	imcb_log( ic, "Requesting OAuth access token" );
	463
	464	/* Don't do it here because the caller may get confused if the contact
	465	we're currently sending a message to is deleted. */
	466	b_timeout_add( 1, sasl_oauth2_remove_contact, ic );
	467
	468	code = g_strdup( msg );
	469	g_strstrip( code );
	470	ret = oauth2_access_token( &oauth2_service_google, OAUTH2_AUTH_CODE,
	471	code, sasl_oauth2_got_token, ic );
	472
	473	g_free( code );
	474	return ret;
	475	}
	476
	477	int sasl_oauth2_refresh( struct im_connection ic, const char refresh_token )
	478	{
	479	return oauth2_access_token( &oauth2_service_google, OAUTH2_AUTH_REFRESH,
	480	refresh_token, sasl_oauth2_got_token, ic );
	481	}
	482
	483	static void sasl_oauth2_got_token( gpointer data, const char access_token, const char refresh_token )
	484	{
	485	struct im_connection *ic = data;
	486	struct jabber_data *jd;
	487
	488	if( g_slist_find( jabber_connections, ic ) == NULL )
	489	return;
	490
	491	jd = ic->proto_data;
	492
	493	if( access_token == NULL )
	494	{
	495	imcb_error( ic, "OAuth failure (missing access token)" );
	496	imc_logout( ic, TRUE );
[e1c926f]	497	return;
[4a5d885]	498	}
	499	if( refresh_token != NULL )
	500	{
	501	g_free( ic->acc->pass );
	502	ic->acc->pass = g_strdup_printf( "refresh_token=%s", refresh_token );
	503	}
	504
	505	g_free( jd->oauth2_access_token );
	506	jd->oauth2_access_token = g_strdup( access_token );
	507
	508	jabber_connect( ic );
	509	}

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