diff options
Diffstat (limited to 'protocols/jabber/sasl.c')
| -rw-r--r-- | protocols/jabber/sasl.c | 332 | 
1 files changed, 332 insertions, 0 deletions
| diff --git a/protocols/jabber/sasl.c b/protocols/jabber/sasl.c new file mode 100644 index 00000000..68953ced --- /dev/null +++ b/protocols/jabber/sasl.c @@ -0,0 +1,332 @@ +/***************************************************************************\ +*                                                                           * +*  BitlBee - An IRC to IM gateway                                           * +*  Jabber module - SASL authentication                                      * +*                                                                           * +*  Copyright 2006 Wilmer van der Gaast <wilmer@gaast.net>                   * +*                                                                           * +*  This program is free software; you can redistribute it and/or modify     * +*  it under the terms of the GNU General Public License as published by     * +*  the Free Software Foundation; either version 2 of the License, or        * +*  (at your option) any later version.                                      * +*                                                                           * +*  This program is distributed in the hope that it will be useful,          * +*  but WITHOUT ANY WARRANTY; without even the implied warranty of           * +*  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the            * +*  GNU General Public License for more details.                             * +*                                                                           * +*  You should have received a copy of the GNU General Public License along  * +*  with this program; if not, write to the Free Software Foundation, Inc.,  * +*  51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.              * +*                                                                           * +\***************************************************************************/ + +#include "jabber.h" +#include "base64.h" + +xt_status sasl_pkt_mechanisms( struct xt_node *node, gpointer data ) +{ +	struct gaim_connection *gc = data; +	struct jabber_data *jd = gc->proto_data; +	struct xt_node *c, *reply; +	char *s; +	int sup_plain = 0, sup_digest = 0; +	 +	if( !sasl_supported( gc ) ) +	{ +		/* Should abort this now, since we should already be doing +		   IQ authentication. Strange things happen when you try +		   to do both... */ +		serv_got_crap( gc, "XMPP 1.0 non-compliant server seems to support SASL, please report this as a BitlBee bug!" ); +		return XT_HANDLED; +	} +	 +	s = xt_find_attr( node, "xmlns" ); +	if( !s || strcmp( s, XMLNS_SASL ) != 0 ) +	{ +		signoff( gc ); +		return XT_ABORT; +	} +	 +	c = node->children; +	while( ( c = xt_find_node( c, "mechanism" ) ) ) +	{ +		if( c->text && g_strcasecmp( c->text, "PLAIN" ) == 0 ) +			sup_plain = 1; +		if( c->text && g_strcasecmp( c->text, "DIGEST-MD5" ) == 0 ) +			sup_digest = 1; +		 +		c = c->next; +	} +	 +	if( !sup_plain && !sup_digest ) +	{ +		hide_login_progress( gc, "No known SASL authentication schemes supported" ); +		signoff( gc ); +		return XT_ABORT; +	} +	 +	reply = xt_new_node( "auth", NULL, NULL ); +	xt_add_attr( reply, "xmlns", XMLNS_SASL ); +	 +	if( sup_digest ) +	{ +		xt_add_attr( reply, "mechanism", "DIGEST-MD5" ); +		 +		/* The rest will be done later, when we receive a <challenge/>. */ +	} +	else if( sup_plain ) +	{ +		int len; +		 +		xt_add_attr( reply, "mechanism", "PLAIN" ); +		 +		/* With SASL PLAIN in XMPP, the text should be b64(\0user\0pass) */ +		len = strlen( jd->username ) + strlen( gc->acc->pass ) + 2; +		s = g_malloc( len + 1 ); +		s[0] = 0; +		strcpy( s + 1, jd->username ); +		strcpy( s + 2 + strlen( jd->username ), gc->acc->pass ); +		reply->text = base64_encode( s, len ); +		reply->text_len = strlen( reply->text ); +		g_free( s ); +	} +	 +	if( !jabber_write_packet( gc, reply ) ) +	{ +		xt_free_node( reply ); +		return XT_ABORT; +	} +	xt_free_node( reply ); +	 +	/* To prevent classic authentication from happening. */ +	jd->flags |= JFLAG_STREAM_STARTED; +	 +	return XT_HANDLED; +} + +static char *sasl_get_part( char *data, char *field ) +{ +	int i, len; +	 +	len = strlen( field ); +	 +	if( g_strncasecmp( data, field, len ) == 0 && data[len] == '=' ) +	{ +		i = strlen( field ) + 1; +	} +	else +	{ +		for( i = 0; data[i]; i ++ ) +		{ +			/* If we have a ", skip until it's closed again. */ +			if( data[i] == '"' ) +			{ +				i ++; +				while( data[i] != '"' || data[i-1] == '\\' ) +					i ++; +			} +			 +			/* If we got a comma, we got a new field. Check it. */ +			if( data[i] == ',' && +			    g_strncasecmp( data + i + 1, field, len ) == 0 && +			    data[i+len+1] == '=' ) +			{ +				i += len + 2; +				break; +			} +		} +	} +	 +	if( data[i] == '"' ) +	{ +		int j; +		char *ret; +		 +		i ++; +		len = 0; +		while( data[i+len] != '"' || data[i+len-1] == '\\' ) +			len ++; +		 +		ret = g_strndup( data + i, len ); +		for( i = j = 0; ret[i]; i ++ ) +		{ +			if( ret[i] == '\\' ) +			{ +				ret[j++] = ret[++i]; +			} +			else +			{ +				ret[j++] = ret[i]; +			} +		} +		ret[j] = 0; +		 +		return ret; +	} +	else if( data[i] ) +	{ +		len = 0; +		while( data[i+len] && data[i+len] != ',' ) +			len ++; +		 +		return g_strndup( data + i, len ); +	} +	else +	{ +		return NULL; +	} +} + +xt_status sasl_pkt_challenge( struct xt_node *node, gpointer data ) +{ +	struct gaim_connection *gc = data; +	struct jabber_data *jd = gc->proto_data; +	struct xt_node *reply = NULL; +	char *nonce = NULL, *realm = NULL, *cnonce = NULL, cnonce_bin[30]; +	char *digest_uri = NULL; +	char *dec = NULL; +	char *s = NULL; +	xt_status ret = XT_ABORT; +	 +	if( node->text_len == 0 ) +		goto error; +	 +	dec = frombase64( node->text ); +	 +	if( !( s = sasl_get_part( dec, "rspauth" ) ) ) +	{ +		/* See RFC 2831 for for information. */ +		md5_state_t A1, A2, H; +		md5_byte_t A1r[16], A2r[16], Hr[16]; +		char A1h[33], A2h[33], Hh[33]; +		int i; +		 +		nonce = sasl_get_part( dec, "nonce" ); +		realm = sasl_get_part( dec, "realm" ); +		 +		if( !nonce ) +			goto error; +		 +		/* Jabber.Org considers the realm part optional and doesn't +		   specify one. Oh well, actually they're right, but still, +		   don't know if this is right... */ +		if( !realm ) +			realm = g_strdup( jd->server ); +		 +		random_bytes( (unsigned char *) cnonce_bin, sizeof( cnonce_bin ) ); +		cnonce = base64_encode( cnonce_bin, sizeof( cnonce_bin ) ); +		digest_uri = g_strdup_printf( "%s/%s", "xmpp", jd->server ); +		 +		/* Generate the MD5 hash of username:realm:password, +		   I decided to call it H. */ +		md5_init( &H ); +		s = g_strdup_printf( "%s:%s:%s", jd->username, realm, gc->acc->pass ); +		md5_append( &H, (unsigned char *) s, strlen( s ) ); +		g_free( s ); +		md5_finish( &H, Hr ); +		 +		/* Now generate the hex. MD5 hash of H:nonce:cnonce, called A1. */ +		md5_init( &A1 ); +		s = g_strdup_printf( ":%s:%s", nonce, cnonce ); +		md5_append( &A1, Hr, 16 ); +		md5_append( &A1, (unsigned char *) s, strlen( s ) ); +		g_free( s ); +		md5_finish( &A1, A1r ); +		for( i = 0; i < 16; i ++ ) +			sprintf( A1h + i * 2, "%02x", A1r[i] ); +		 +		/* A2... */ +		md5_init( &A2 ); +		s = g_strdup_printf( "%s:%s", "AUTHENTICATE", digest_uri ); +		md5_append( &A2, (unsigned char *) s, strlen( s ) ); +		g_free( s ); +		md5_finish( &A2, A2r ); +		for( i = 0; i < 16; i ++ ) +			sprintf( A2h + i * 2, "%02x", A2r[i] ); +		 +		/* Final result: A1:nonce:00000001:cnonce:auth:A2. Let's reuse H for it. */ +		md5_init( &H ); +		s = g_strdup_printf( "%s:%s:%s:%s:%s:%s", A1h, nonce, "00000001", cnonce, "auth", A2h ); +		md5_append( &H, (unsigned char *) s, strlen( s ) ); +		g_free( s ); +		md5_finish( &H, Hr ); +		for( i = 0; i < 16; i ++ ) +			sprintf( Hh + i * 2, "%02x", Hr[i] ); +		 +		/* Now build the SASL response string: */ +		g_free( dec ); +		dec = g_strdup_printf( "username=\"%s\",realm=\"%s\",nonce=\"%s\",cnonce=\"%s\"," +		                       "nc=%08x,qop=auth,digest-uri=\"%s\",response=%s,charset=%s", +		                       jd->username, realm, nonce, cnonce, 1, digest_uri, Hh, "utf-8" ); +		s = tobase64( dec ); +	} +	else +	{ +		/* We found rspauth, but don't really care... */ +		g_free( s ); +		s = NULL; +	} +	 +	reply = xt_new_node( "response", s, NULL ); +	xt_add_attr( reply, "xmlns", XMLNS_SASL ); +	 +	if( !jabber_write_packet( gc, reply ) ) +		goto silent_error; +	 +	ret = XT_HANDLED; +	goto silent_error; + +error: +	hide_login_progress( gc, "Incorrect SASL challenge received" ); +	signoff( gc ); + +silent_error: +	g_free( digest_uri ); +	g_free( cnonce ); +	g_free( nonce ); +	g_free( realm ); +	g_free( dec ); +	g_free( s ); +	xt_free_node( reply ); +	 +	return ret; +} + +xt_status sasl_pkt_result( struct xt_node *node, gpointer data ) +{ +	struct gaim_connection *gc = data; +	struct jabber_data *jd = gc->proto_data; +	char *s; +	 +	s = xt_find_attr( node, "xmlns" ); +	if( !s || strcmp( s, XMLNS_SASL ) != 0 ) +	{ +		signoff( gc ); +		return XT_ABORT; +	} +	 +	if( strcmp( node->name, "success" ) == 0 ) +	{ +		set_login_progress( gc, 1, "Authentication finished" ); +		jd->flags |= JFLAG_AUTHENTICATED | JFLAG_STREAM_RESTART; +	} +	else if( strcmp( node->name, "failure" ) == 0 ) +	{ +		hide_login_progress( gc, "Authentication failure" ); +		signoff( gc ); +		return XT_ABORT; +	} +	 +	return XT_HANDLED; +} + +/* This one is needed to judge if we'll do authentication using IQ or SASL. +   It's done by checking if the <stream:stream> from the server has a +   version attribute. I don't know if this is the right way though... */ +gboolean sasl_supported( struct gaim_connection *gc ) +{ +	struct jabber_data *jd = gc->proto_data; +	 +	return ( (void*) ( jd->xt && jd->xt->root && xt_find_attr( jd->xt->root, "version" ) ) ) != NULL; +} | 
