import sys import logging import struct from threading import Thread, Event from hashlib import sha1 from select import select from uuid import uuid4 from sleekxmpp.plugins.base import base_plugin from sleekxmpp.xmlstream.handler import Callback from sleekxmpp.xmlstream.matcher import StanzaPath from socks import socksocket, PROXY_TYPE_SOCKS5 import stanza # Registers the sleekxmpp logger log = logging.getLogger(__name__) class xep_0065(base_plugin): """ XEP-0065 In-Band Bytestreams """ description = "In-Band Bytestreams" dependencies = set(['xep_0030', ]) xep = '0065' # A dict contains for each SID, the proxy thread currently # running. proxy_threads = {} def plugin_init(self): """ Initializes the xep_0065 plugin and all event callbacks. """ # Shortcuts to access to the xep_0030 plugin. self.disco = self.xmpp['xep_0030'] # Handler for the streamhost stanza. self.xmpp.registerHandler( Callback('In-Band Bytestreams', StanzaPath('iq@type=set/q/streamhost'), self._handle_streamhost)) # Handler for the streamhost-used stanza. self.xmpp.registerHandler( Callback('In-Band Bytestreams', StanzaPath('iq@type=result/q/streamhost-used'), self._handle_streamhost_used)) def handshake(self, to, streamer=None): """ Starts the handshake to establish the socks5 bytestreams connection. """ # Discovers the proxy. self.streamer = streamer or self.discover_proxy() # Requester requests network address from the proxy. streamhost = self.get_network_address(self.streamer) self.proxy_host = streamhost['q']['streamhost']['host'] self.proxy_port = streamhost['q']['streamhost']['port'] # Generates the SID for this new handshake. sid = uuid4().hex # Requester initiates S5B negotation with Target by sending # IQ-set that includes the JabberID and network address of # StreamHost as well as the StreamID (SID) of the proposed # bytestream. iq = self.xmpp.Iq(sto=to, stype='set') iq['q']['sid'] = sid iq['q']['streamhost']['jid'] = self.streamer iq['q']['streamhost']['host'] = self.proxy_host iq['q']['streamhost']['port'] = self.proxy_port # Sends the new IQ. return iq.send() def discover_proxy(self): """ Auto-discovers (using XEP 0030) the available bytestream proxy on the XMPP server. Returns the JID of the proxy. """ # Gets all disco items. disco_items = self.disco.get_items(self.xmpp.server) for item in disco_items['disco_items']['items']: # For each items, gets the disco info. disco_info = self.disco.get_info(item[0]) # Gets and verifies if the identity is a bytestream proxy. identities = disco_info['disco_info']['identities'] for identity in identities: if identity[0] == 'proxy' and identity[1] == 'bytestreams': # Returns when the first occurence is found. return '%s' % disco_info['from'] def get_network_address(self, streamer): """ Gets the streamhost information of the proxy. streamer : The jid of the proxy. """ iq = self.xmpp.Iq(sto=streamer, stype='get') iq['q'] # Adds the query eleme to the iq. return iq.send() def _handle_streamhost(self, iq): """ Handles all streamhost stanzas. """ # Registers the streamhost info. self.streamer = iq['q']['streamhost']['jid'] self.proxy_host = iq['q']['streamhost']['host'] self.proxy_port = iq['q']['streamhost']['port'] # Sets the SID, the requester and the target. sid = iq['q']['sid'] requester = '%s' % iq['from'] target = '%s' % self.xmpp.boundjid # Next the Target attempts to open a standard TCP socket on # the network address of the Proxy. self.proxy_thread = Proxy(sid, requester, target, self.proxy_host, self.proxy_port, self.on_recv) self.proxy_thread.start() # Registers the new thread in the proxy_thread dict. self.proxy_threads[sid] = self.proxy_thread # Wait until the proxy is connected self.proxy_thread.connected.wait() # Replies to the incoming iq with a streamhost-used stanza. res_iq = iq.reply() res_iq['q']['sid'] = sid res_iq['q']['streamhost-used']['jid'] = self.streamer # Sends the IQ return res_iq.send() def _handle_streamhost_used(self, iq): """ Handles all streamhost-used stanzas. """ # Sets the SID, the requester and the target. sid = iq['q']['sid'] requester = '%s' % self.xmpp.boundjid target = '%s' % iq['from'] # The Requester will establish a connection to the SOCKS5 # proxy in the same way the Target did. self.proxy_thread = Proxy(sid, requester, target, self.proxy_host, self.proxy_port, self.on_recv) self.proxy_thread.start() # Registers the new thread in the proxy_thread dict. self.proxy_threads[sid] = self.proxy_thread # Wait until the proxy is connected self.proxy_thread.connected.wait() # Requester sends IQ-set to StreamHost requesting that # StreamHost activate the bytestream associated with the # StreamID. self.activate(iq['q']['sid'], target) def activate(self, sid, to): """ IQ-set to StreamHost requesting that StreamHost activate the bytestream associated with the StreamID. """ # Creates the activate IQ. act_iq = self.xmpp.Iq(sto=self.streamer, stype='set') act_iq['q']['sid'] = sid act_iq['q']['activate'] = to # Send the IQ. act_iq.send() def send(self, sid, msg): """ Sends the msg to the socket. sid : The SID to retrieve the good proxy stored in the proxy_threads dict msg : The message data. """ proxy = self.proxy_threads.get(sid) if proxy: proxy.send(msg) else: # TODO: raise an exception. pass def on_recv(self, sid, data): """ Called when receiving data """ if not data: try: del self.proxy_threads[sid] except KeyError: # TODO: internal error, raise an exception ? pass else: log.debug('Received data: %s' % data) self.xmpp.event('socks_recv', data) class Proxy(Thread): """ Establishes in a thread a connection between the client and the server-side Socks5 proxy. """ def __init__(self, sid, requester, target, proxy, proxy_port, on_recv): """ Initializes the proxy thread. sid : The StreamID. requester : The JID of the requester. target : The JID of the target. proxy_host : The hostname or the IP of the proxy. proxy_port : The port of the proxy. or on_recv : A callback called when data are received from the socket. """ # Initializes the thread. Thread.__init__(self) # Because the xep_0065 plugin uses the proxy_port as string, # the Proxy class accepts the proxy_port argument as a string # or an integer. Here, we force to use the port as an integer. proxy_port = int(proxy_port) # Creates a connected event to warn when to proxy is # connected. self.connected = Event() # Registers the arguments. self.sid = sid self.requester = requester self.target = target self.proxy = proxy self.proxy_port = proxy_port self.on_recv = on_recv def run(self): """ Starts the thread. """ # Creates the socks5 proxy socket self.s = socksocket() self.s.setproxy(PROXY_TYPE_SOCKS5, self.proxy, port=self.proxy_port) # The hostname MUST be SHA1(SID + Requester JID + Target JID) # where the output is hexadecimal-encoded (not binary). digest = sha1() digest.update(self.sid) # SID digest.update(self.requester) # Requester JID digest.update(self.target) # Target JID # Computes the digest in hex. dest = '%s' % digest.hexdigest() # The port MUST be 0. self.s.connect((dest, 0)) log.info('Socket connected.') self.connected.set() # Listen for data on the socket self.listen() # Listen returns when the socket must be closed. self.s.close() log.info('Socket closed.') def listen(self): """ Listen for data on the socket. When receiving data, call the callback on_recv callable. """ socket_open = True while socket_open: ins, out, err = select([self.s, ], [], []) for s in ins: data = self.recv_size(self.s) if not data: socket_open = False self.on_recv(self.sid, data) def recv_size(self, the_socket): total_len = 0 total_data = [] size = sys.maxint size_data = sock_data = '' recv_size = 8192 while total_len < size: sock_data = the_socket.recv(recv_size) if not sock_data: return ''.join(total_data) if not total_data: if len(sock_data) > 4: size_data += sock_data size = struct.unpack('>i', size_data[:4])[0] recv_size = size if recv_size > 524288: recv_size = 524288 total_data.append(size_data[4:]) else: size_data += sock_data else: total_data.append(sock_data) total_len = sum([len(i) for i in total_data]) return ''.join(total_data) def send(self, msg): """ Sends the data over the socket. """ self.s.sendall(msg)