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# -*- test-case-name: twisted.words.test.test_jabberxmlstream -*-#
 # Copyright (c) Twisted Matrix Laboratories.
 # See LICENSE for details.
 
 """
 XMPP XML Streams
 
 Building blocks for setting up XML Streams, including helping classes for
 doing authentication on either client or server side, and working with XML
 Stanzas.
 """
 
 from hashlib import sha1
 from zope.interface import directlyProvides, implements
 
 from twisted.internet import defer, protocol
 from twisted.internet.error import ConnectionLost
 from twisted.python import failure, log, randbytes
 from twisted.words.protocols.jabber import error, ijabber, jid
 from twisted.words.xish import domish, xmlstream
 from twisted.words.xish.xmlstream import STREAM_CONNECTED_EVENT
 from twisted.words.xish.xmlstream import STREAM_START_EVENT
 from twisted.words.xish.xmlstream import STREAM_END_EVENT
 from twisted.words.xish.xmlstream import STREAM_ERROR_EVENT
 
 try:
 from twisted.internet import ssl
 except ImportError:
 ssl = None
 if ssl and not ssl.supported:
 ssl = None
 
 STREAM_AUTHD_EVENT = intern("//event/stream/authd")
 INIT_FAILED_EVENT = intern("//event/xmpp/initfailed")
 
 NS_STREAMS = 'http://etherx.jabber.org/streams'
 NS_XMPP_TLS = 'urn:ietf:params:xml:ns:xmpp-tls'
 
 Reset = object()
 
 def hashPassword(sid, password):
 """
 Create a SHA1-digest string of a session identifier and password.
 
 @param sid: The stream session identifier.
 @type sid: C{unicode}.
 @param password: The password to be hashed.
 @type password: C{unicode}.
 """
 if not isinstance(sid, unicode):
 raise TypeError("The session identifier must be a unicode object")
 if not isinstance(password, unicode):
 raise TypeError("The password must be a unicode object")
 input = u"%s%s" % (sid, password)
 return sha1(input.encode('utf-8')).hexdigest()
 
 
 
 class Authenticator:
 """
 Base class for business logic of initializing an XmlStream
 
 Subclass this object to enable an XmlStream to initialize and authenticate
 to different types of stream hosts (such as clients, components, etc.).
 
 Rules:
 1. The Authenticator MUST dispatch a L{STREAM_AUTHD_EVENT} when the
 stream has been completely initialized.
 2. The Authenticator SHOULD reset all state information when
 L{associateWithStream} is called.
 3. The Authenticator SHOULD override L{streamStarted}, and start
 initialization there.
 
 @type xmlstream: L{XmlStream}
 @ivar xmlstream: The XmlStream that needs authentication
 
 @note: the term authenticator is historical. Authenticators perform
 all steps required to prepare the stream for the exchange
 of XML stanzas.
 """
 
 def __init__(self):
 self.xmlstream = None
 
 
 def connectionMade(self):
 """
 Called by the XmlStream when the underlying socket connection is
 in place.
 
 This allows the Authenticator to send an initial root element, if it's
 connecting, or wait for an inbound root from the peer if it's accepting
 the connection.
 
 Subclasses can use self.xmlstream.send() to send any initial data to
 the peer.
 """
 
 
 def streamStarted(self, rootElement):
 """
 Called by the XmlStream when the stream has started.
 
 A stream is considered to have started when the start tag of the root
 element has been received.
 
 This examines C{rootElement} to see if there is a version attribute.
 If absent, C{0.0} is assumed per RFC 3920. Subsequently, the
 minimum of the version from the received stream header and the
 value stored in L{xmlstream} is taken and put back in L{xmlstream}.
 
 Extensions of this method can extract more information from the
 stream header and perform checks on them, optionally sending
 stream errors and closing the stream.
 """
 if rootElement.hasAttribute("version"):
 version = rootElement["version"].split(".")
 try:
 version = (int(version[0]), int(version[1]))
 except (IndexError, ValueError):
 version = (0, 0)
 else:
 version = (0, 0)
 
 self.xmlstream.version = min(self.xmlstream.version, version)
 
 
 def associateWithStream(self, xmlstream):
 """
 Called by the XmlStreamFactory when a connection has been made
 to the requested peer, and an XmlStream object has been
 instantiated.
 
 The default implementation just saves a handle to the new
 XmlStream.
 
 @type xmlstream: L{XmlStream}
 @param xmlstream: The XmlStream that will be passing events to this
 Authenticator.
 
 """
 self.xmlstream = xmlstream
 
 
 
 class ConnectAuthenticator(Authenticator):
 """
 Authenticator for initiating entities.
 """
 
 namespace = None
 
 def __init__(self, otherHost):
 self.otherHost = otherHost
 
 
 def connectionMade(self):
 self.xmlstream.namespace = self.namespace
 self.xmlstream.otherEntity = jid.internJID(self.otherHost)
 self.xmlstream.sendHeader()
 
 
 def initializeStream(self):
 """
 Perform stream initialization procedures.
 
 An L{XmlStream} holds a list of initializer objects in its
 C{initializers} attribute. This method calls these initializers in
 order and dispatches the C{STREAM_AUTHD_EVENT} event when the list has
 been successfully processed. Otherwise it dispatches the
 C{INIT_FAILED_EVENT} event with the failure.
 
 Initializers may return the special L{Reset} object to halt the
 initialization processing. It signals that the current initializer was
 successfully processed, but that the XML Stream has been reset. An
 example is the TLSInitiatingInitializer.
 """
 
 def remove_first(result):
 self.xmlstream.initializers.pop(0)
 
 return result
 
 def do_next(result):
 """
 Take the first initializer and process it.
 
 On success, the initializer is removed from the list and
 then next initializer will be tried.
 """
 
 if result is Reset:
 return None
 
 try:
 init = self.xmlstream.initializers[0]
 except IndexError:
 self.xmlstream.dispatch(self.xmlstream, STREAM_AUTHD_EVENT)
 return None
 else:
 d = defer.maybeDeferred(init.initialize)
 d.addCallback(remove_first)
 d.addCallback(do_next)
 return d
 
 d = defer.succeed(None)
 d.addCallback(do_next)
 d.addErrback(self.xmlstream.dispatch, INIT_FAILED_EVENT)
 
 
 def streamStarted(self, rootElement):
 """
 Called by the XmlStream when the stream has started.
 
 This extends L{Authenticator.streamStarted} to extract further stream
 headers from C{rootElement}, optionally wait for stream features being
 received and then call C{initializeStream}.
 """
 
 Authenticator.streamStarted(self, rootElement)
 
 self.xmlstream.sid = rootElement.getAttribute("id")
 
 if rootElement.hasAttribute("from"):
 self.xmlstream.otherEntity = jid.internJID(rootElement["from"])
 
 # Setup observer for stream features, if applicable
 if self.xmlstream.version >= (1, 0):
 def onFeatures(element):
 features = {}
 for feature in element.elements():
 features[(feature.uri, feature.name)] = feature
 
 self.xmlstream.features = features
 self.initializeStream()
 
 self.xmlstream.addOnetimeObserver('/features[@xmlns="%s"]' %
 NS_STREAMS,
 onFeatures)
 else:
 self.initializeStream()
 
 
 
 class ListenAuthenticator(Authenticator):
 """
 Authenticator for receiving entities.
 """
 
 namespace = None
 
 def associateWithStream(self, xmlstream):
 """
 Called by the XmlStreamFactory when a connection has been made.
 
 Extend L{Authenticator.associateWithStream} to set the L{XmlStream}
 to be non-initiating.
 """
 Authenticator.associateWithStream(self, xmlstream)
 self.xmlstream.initiating = False
 
 
 def streamStarted(self, rootElement):
 """
 Called by the XmlStream when the stream has started.
 
 This extends L{Authenticator.streamStarted} to extract further
 information from the stream headers from C{rootElement}.
 """
 Authenticator.streamStarted(self, rootElement)
 
 self.xmlstream.namespace = rootElement.defaultUri
 
 if rootElement.hasAttribute("to"):
 self.xmlstream.thisEntity = jid.internJID(rootElement["to"])
 
 self.xmlstream.prefixes = {}
 for prefix, uri in rootElement.localPrefixes.iteritems():
 self.xmlstream.prefixes[uri] = prefix
 
 self.xmlstream.sid = unicode(randbytes.secureRandom(8).encode('hex'))
 
 
 
 class FeatureNotAdvertized(Exception):
 """
 Exception indicating a stream feature was not advertized, while required by
 the initiating entity.
 """
 
 
 
 class BaseFeatureInitiatingInitializer(object):
 """
 Base class for initializers with a stream feature.
 
 This assumes the associated XmlStream represents the initiating entity
 of the connection.
 
 @cvar feature: tuple of (uri, name) of the stream feature root element.
 @type feature: tuple of (C{str}, C{str})
 
 @ivar required: whether the stream feature is required to be advertized
 by the receiving entity.
 @type required: C{bool}
 """
 
 implements(ijabber.IInitiatingInitializer)
 
 feature = None
 
 def __init__(self, xs, required=False):
 self.xmlstream = xs
 self.required = required
 
 
 def initialize(self):
 """
 Initiate the initialization.
 
 Checks if the receiving entity advertizes the stream feature. If it
 does, the initialization is started. If it is not advertized, and the
 C{required} instance variable is C{True}, it raises
 L{FeatureNotAdvertized}. Otherwise, the initialization silently
 succeeds.
 """
 
 if self.feature in self.xmlstream.features:
 return self.start()
 elif self.required:
 raise FeatureNotAdvertized
 else:
 return None
 
 
 def start(self):
 """
 Start the actual initialization.
 
 May return a deferred for asynchronous initialization.
 """
 
 
 
 class TLSError(Exception):
 """
 TLS base exception.
 """
 
 
 
 class TLSFailed(TLSError):
 """
 Exception indicating failed TLS negotiation
 """
 
 
 
 class TLSRequired(TLSError):
 """
 Exception indicating required TLS negotiation.
 
 This exception is raised when the receiving entity requires TLS
 negotiation and the initiating does not desire to negotiate TLS.
 """
 
 
 
 class TLSNotSupported(TLSError):
 """
 Exception indicating missing TLS support.
 
 This exception is raised when the initiating entity wants and requires to
 negotiate TLS when the OpenSSL library is not available.
 """
 
 
 
 class TLSInitiatingInitializer(BaseFeatureInitiatingInitializer):
 """
 TLS stream initializer for the initiating entity.
 
 It is strongly required to include this initializer in the list of
 initializers for an XMPP stream. By default it will try to negotiate TLS.
 An XMPP server may indicate that TLS is required. If TLS is not desired,
 set the C{wanted} attribute to False instead of removing it from the list
 of initializers, so a proper exception L{TLSRequired} can be raised.
 
 @ivar wanted: indicates if TLS negotiation is wanted.
 @type wanted: C{bool}
 """
 
 feature = (NS_XMPP_TLS, 'starttls')
 wanted = True
 _deferred = None
 _configurationForTLS = None
 
 def __init__(self, xs, required=True, configurationForTLS=None):
 """
 @param configurationForTLS: An object which creates appropriately
 configured TLS connections. This is passed to C{startTLS} on the
 transport and is preferably created using
 L{twisted.internet.ssl.optionsForClientTLS}.  If C{None}, the
 default is to verify the server certificate against the trust roots
 as provided by the platform. See
 L{twisted.internet._sslverify.platformTrust}.
 @type configurationForTLS: L{IOpenSSLClientConnectionCreator} or
 C{None}
 """
 super(TLSInitiatingInitializer, self).__init__(
 xs, required=required)
 self._configurationForTLS = configurationForTLS
 
 
 def onProceed(self, obj):
 """
 Proceed with TLS negotiation and reset the XML stream.
 """
 
 self.xmlstream.removeObserver('/failure', self.onFailure)
 if self._configurationForTLS:
 ctx = self._configurationForTLS
 else:
 ctx = ssl.optionsForClientTLS(self.xmlstream.otherEntity.host)
 self.xmlstream.transport.startTLS(ctx)
 self.xmlstream.reset()
 self.xmlstream.sendHeader()
 self._deferred.callback(Reset)
 
 
 def onFailure(self, obj):
 self.xmlstream.removeObserver('/proceed', self.onProceed)
 self._deferred.errback(TLSFailed())
 
 
 def start(self):
 """
 Start TLS negotiation.
 
 This checks if the receiving entity requires TLS, the SSL library is
 available and uses the C{required} and C{wanted} instance variables to
 determine what to do in the various different cases.
 
 For example, if the SSL library is not available, and wanted and
 required by the user, it raises an exception. However if it is not
 required by both parties, initialization silently succeeds, moving
 on to the next step.
 """
 if self.wanted:
 if ssl is None:
 if self.required:
 return defer.fail(TLSNotSupported())
 else:
 return defer.succeed(None)
 else:
 pass
 elif self.xmlstream.features[self.feature].required:
 return defer.fail(TLSRequired())
 else:
 return defer.succeed(None)
 
 self._deferred = defer.Deferred()
 self.xmlstream.addOnetimeObserver("/proceed", self.onProceed)
 self.xmlstream.addOnetimeObserver("/failure", self.onFailure)
 self.xmlstream.send(domish.Element((NS_XMPP_TLS, "starttls")))
 return self._deferred
 
 
 
 class XmlStream(xmlstream.XmlStream):
 """
 XMPP XML Stream protocol handler.
 
 @ivar version: XML stream version as a tuple (major, minor). Initially,
 this is set to the minimally supported version. Upon
 receiving the stream header of the peer, it is set to the
 minimum of that value and the version on the received
 header.
 @type version: (C{int}, C{int})
 @ivar namespace: default namespace URI for stream
 @type namespace: C{unicode}
 @ivar thisEntity: JID of this entity
 @type thisEntity: L{JID}
 @ivar otherEntity: JID of the peer entity
 @type otherEntity: L{JID}
 @ivar sid: session identifier
 @type sid: C{unicode}
 @ivar initiating: True if this is the initiating stream
 @type initiating: C{bool}
 @ivar features: map of (uri, name) to stream features element received from
 the receiving entity.
 @type features: C{dict} of (C{unicode}, C{unicode}) to L{domish.Element}.
 @ivar prefixes: map of URI to prefixes that are to appear on stream
 header.
 @type prefixes: C{dict} of C{unicode} to C{unicode}
 @ivar initializers: list of stream initializer objects
 @type initializers: C{list} of objects that provide L{IInitializer}
 @ivar authenticator: associated authenticator that uses C{initializers} to
 initialize the XML stream.
 """
 
 version = (1, 0)
 namespace = 'invalid'
 thisEntity = None
 otherEntity = None
 sid = None
 initiating = True
 
 _headerSent = False     # True if the stream header has been sent
 
 def __init__(self, authenticator):
 xmlstream.XmlStream.__init__(self)
 
 self.prefixes = {NS_STREAMS: 'stream'}
 self.authenticator = authenticator
 self.initializers = []
 self.features = {}
 
 # Reset the authenticator
 authenticator.associateWithStream(self)
 
 
 def _callLater(self, *args, **kwargs):
 from twisted.internet import reactor
 return reactor.callLater(*args, **kwargs)
 
 
 def reset(self):
 """
 Reset XML Stream.
 
 Resets the XML Parser for incoming data. This is to be used after
 successfully negotiating a new layer, e.g. TLS and SASL. Note that
 registered event observers will continue to be in place.
 """
 self._headerSent = False
 self._initializeStream()
 
 
 def onStreamError(self, errelem):
 """
 Called when a stream:error element has been received.
 
 Dispatches a L{STREAM_ERROR_EVENT} event with the error element to
 allow for cleanup actions and drops the connection.
 
 @param errelem: The received error element.
 @type errelem: L{domish.Element}
 """
 self.dispatch(failure.Failure(error.exceptionFromStreamError(errelem)),
 STREAM_ERROR_EVENT)
 self.transport.loseConnection()
 
 
 def sendHeader(self):
 """
 Send stream header.
 """
 # set up optional extra namespaces
 localPrefixes = {}
 for uri, prefix in self.prefixes.iteritems():
 if uri != NS_STREAMS:
 localPrefixes[prefix] = uri
 
 rootElement = domish.Element((NS_STREAMS, 'stream'), self.namespace,
 localPrefixes=localPrefixes)
 
 if self.otherEntity:
 rootElement['to'] = self.otherEntity.userhost()
 
 if self.thisEntity:
 rootElement['from'] = self.thisEntity.userhost()
 
 if not self.initiating and self.sid:
 rootElement['id'] = self.sid
 
 if self.version >= (1, 0):
 rootElement['version'] = "%d.%d" % self.version
 
 self.send(rootElement.toXml(prefixes=self.prefixes, closeElement=0))
 self._headerSent = True
 
 
 def sendFooter(self):
 """
 Send stream footer.
 """
 self.send('</stream:stream>')
 
 
 def sendStreamError(self, streamError):
 """
 Send stream level error.
 
 If we are the receiving entity, and haven't sent the header yet,
 we sent one first.
 
 After sending the stream error, the stream is closed and the transport
 connection dropped.
 
 @param streamError: stream error instance
 @type streamError: L{error.StreamError}
 """
 if not self._headerSent and not self.initiating:
 self.sendHeader()
 
 if self._headerSent:
 self.send(streamError.getElement())
 self.sendFooter()
 
 self.transport.loseConnection()
 
 
 def send(self, obj):
 """
 Send data over the stream.
 
 This overrides L{xmlstream.Xmlstream.send} to use the default namespace
 of the stream header when serializing L{domish.IElement}s. It is
 assumed that if you pass an object that provides L{domish.IElement},
 it represents a direct child of the stream's root element.
 """
 if domish.IElement.providedBy(obj):
 obj = obj.toXml(prefixes=self.prefixes,
 defaultUri=self.namespace,
 prefixesInScope=self.prefixes.values())
 
 xmlstream.XmlStream.send(self, obj)
 
 
 def connectionMade(self):
 """
 Called when a connection is made.
 
 Notifies the authenticator when a connection has been made.
 """
 xmlstream.XmlStream.connectionMade(self)
 self.authenticator.connectionMade()
 
 
 def onDocumentStart(self, rootElement):
 """
 Called when the stream header has been received.
 
 Extracts the header's C{id} and C{version} attributes from the root
 element. The C{id} attribute is stored in our C{sid} attribute and the
 C{version} attribute is parsed and the minimum of the version we sent
 and the parsed C{version} attribute is stored as a tuple (major, minor)
 in this class' C{version} attribute. If no C{version} attribute was
 present, we assume version 0.0.
 
 If appropriate (we are the initiating stream and the minimum of our and
 the other party's version is at least 1.0), a one-time observer is
 registered for getting the stream features. The registered function is
 C{onFeatures}.
 
 Ultimately, the authenticator's C{streamStarted} method will be called.
 
 @param rootElement: The root element.
 @type rootElement: L{domish.Element}
 """
 xmlstream.XmlStream.onDocumentStart(self, rootElement)
 
 # Setup observer for stream errors
 self.addOnetimeObserver("/error[@xmlns='%s']" % NS_STREAMS,
 self.onStreamError)
 
 self.authenticator.streamStarted(rootElement)
 
 
 
 class XmlStreamFactory(xmlstream.XmlStreamFactory):
 """
 Factory for Jabber XmlStream objects as a reconnecting client.
 
 Note that this differs from L{xmlstream.XmlStreamFactory} in that
 it generates Jabber specific L{XmlStream} instances that have
 authenticators.
 """
 
 protocol = XmlStream
 
 def __init__(self, authenticator):
 xmlstream.XmlStreamFactory.__init__(self, authenticator)
 self.authenticator = authenticator
 
 
 
 class XmlStreamServerFactory(xmlstream.BootstrapMixin,
 protocol.ServerFactory):
 """
 Factory for Jabber XmlStream objects as a server.
 
 @since: 8.2.
 @ivar authenticatorFactory: Factory callable that takes no arguments, to
 create a fresh authenticator to be associated
 with the XmlStream.
 """
 
 protocol = XmlStream
 
 def __init__(self, authenticatorFactory):
 xmlstream.BootstrapMixin.__init__(self)
 self.authenticatorFactory = authenticatorFactory
 
 
 def buildProtocol(self, addr):
 """
 Create an instance of XmlStream.
 
 A new authenticator instance will be created and passed to the new
 XmlStream. Registered bootstrap event observers are installed as well.
 """
 authenticator = self.authenticatorFactory()
 xs = self.protocol(authenticator)
 xs.factory = self
 self.installBootstraps(xs)
 return xs
 
 
 
 class TimeoutError(Exception):
 """
 Exception raised when no IQ response has been received before the
 configured timeout.
 """
 
 
 
 def upgradeWithIQResponseTracker(xs):
 """
 Enhances an XmlStream for iq response tracking.
 
 This makes an L{XmlStream} object provide L{IIQResponseTracker}. When a
 response is an error iq stanza, the deferred has its errback invoked with a
 failure that holds a L{StanzaException<error.StanzaException>} that is
 easier to examine.
 """
 def callback(iq):
 """
 Handle iq response by firing associated deferred.
 """
 if getattr(iq, 'handled', False):
 return
 
 try:
 d = xs.iqDeferreds[iq["id"]]
 except KeyError:
 pass
 else:
 del xs.iqDeferreds[iq["id"]]
 iq.handled = True
 if iq['type'] == 'error':
 d.errback(error.exceptionFromStanza(iq))
 else:
 d.callback(iq)
 
 
 def disconnected(_):
 """
 Make sure deferreds do not linger on after disconnect.
 
 This errbacks all deferreds of iq's for which no response has been
 received with a L{ConnectionLost} failure. Otherwise, the deferreds
 will never be fired.
 """
 iqDeferreds = xs.iqDeferreds
 xs.iqDeferreds = {}
 for d in iqDeferreds.itervalues():
 d.errback(ConnectionLost())
 
 xs.iqDeferreds = {}
 xs.iqDefaultTimeout = getattr(xs, 'iqDefaultTimeout', None)
 xs.addObserver(xmlstream.STREAM_END_EVENT, disconnected)
 xs.addObserver('/iq[@type="result"]', callback)
 xs.addObserver('/iq[@type="error"]', callback)
 directlyProvides(xs, ijabber.IIQResponseTracker)
 
 
 
 class IQ(domish.Element):
 """
 Wrapper for an iq stanza.
 
 Iq stanzas are used for communications with a request-response behaviour.
 Each iq request is associated with an XML stream and has its own unique id
 to be able to track the response.
 
 @ivar timeout: if set, a timeout period after which the deferred returned
 by C{send} will have its errback called with a
 L{TimeoutError} failure.
 @type timeout: C{float}
 """
 
 timeout = None
 
 def __init__(self, xmlstream, stanzaType="set"):
 """
 @type xmlstream: L{xmlstream.XmlStream}
 @param xmlstream: XmlStream to use for transmission of this IQ
 
 @type stanzaType: C{str}
 @param stanzaType: IQ type identifier ('get' or 'set')
 """
 domish.Element.__init__(self, (None, "iq"))
 self.addUniqueId()
 self["type"] = stanzaType
 self._xmlstream = xmlstream
 
 
 def send(self, to=None):
 """
 Send out this iq.
 
 Returns a deferred that is fired when an iq response with the same id
 is received. Result responses will be passed to the deferred callback.
 Error responses will be transformed into a
 L{StanzaError<error.StanzaError>} and result in the errback of the
 deferred being invoked.
 
 @rtype: L{defer.Deferred}
 """
 if to is not None:
 self["to"] = to
 
 if not ijabber.IIQResponseTracker.providedBy(self._xmlstream):
 upgradeWithIQResponseTracker(self._xmlstream)
 
 d = defer.Deferred()
 self._xmlstream.iqDeferreds[self['id']] = d
 
 timeout = self.timeout or self._xmlstream.iqDefaultTimeout
 if timeout is not None:
 def onTimeout():
 del self._xmlstream.iqDeferreds[self['id']]
 d.errback(TimeoutError("IQ timed out"))
 
 call = self._xmlstream._callLater(timeout, onTimeout)
 
 def cancelTimeout(result):
 if call.active():
 call.cancel()
 
 return result
 
 d.addBoth(cancelTimeout)
 
 self._xmlstream.send(self)
 return d
 
 
 
 def toResponse(stanza, stanzaType=None):
 """
 Create a response stanza from another stanza.
 
 This takes the addressing and id attributes from a stanza to create a (new,
 empty) response stanza. The addressing attributes are swapped and the id
 copied. Optionally, the stanza type of the response can be specified.
 
 @param stanza: the original stanza
 @type stanza: L{domish.Element}
 @param stanzaType: optional response stanza type
 @type stanzaType: C{str}
 @return: the response stanza.
 @rtype: L{domish.Element}
 """
 
 toAddr = stanza.getAttribute('from')
 fromAddr = stanza.getAttribute('to')
 stanzaID = stanza.getAttribute('id')
 
 response = domish.Element((None, stanza.name))
 if toAddr:
 response['to'] = toAddr
 if fromAddr:
 response['from'] = fromAddr
 if stanzaID:
 response['id'] = stanzaID
 if stanzaType:
 response['type'] = stanzaType
 
 return response
 
 
 
 class XMPPHandler(object):
 """
 XMPP protocol handler.
 
 Classes derived from this class implement (part of) one or more XMPP
 extension protocols, and are referred to as a subprotocol implementation.
 """
 
 implements(ijabber.IXMPPHandler)
 
 def __init__(self):
 self.parent = None
 self.xmlstream = None
 
 
 def setHandlerParent(self, parent):
 self.parent = parent
 self.parent.addHandler(self)
 
 
 def disownHandlerParent(self, parent):
 self.parent.removeHandler(self)
 self.parent = None
 
 
 def makeConnection(self, xs):
 self.xmlstream = xs
 self.connectionMade()
 
 
 def connectionMade(self):
 """
 Called after a connection has been established.
 
 Can be overridden to perform work before stream initialization.
 """
 
 
 def connectionInitialized(self):
 """
 The XML stream has been initialized.
 
 Can be overridden to perform work after stream initialization, e.g. to
 set up observers and start exchanging XML stanzas.
 """
 
 
 def connectionLost(self, reason):
 """
 The XML stream has been closed.
 
 This method can be extended to inspect the C{reason} argument and
 act on it.
 """
 self.xmlstream = None
 
 
 def send(self, obj):
 """
 Send data over the managed XML stream.
 
 @note: The stream manager maintains a queue for data sent using this
 method when there is no current initialized XML stream. This
 data is then sent as soon as a new stream has been established
 and initialized. Subsequently, L{connectionInitialized} will be
 called again. If this queueing is not desired, use C{send} on
 C{self.xmlstream}.
 
 @param obj: data to be sent over the XML stream. This is usually an
 object providing L{domish.IElement}, or serialized XML. See
 L{xmlstream.XmlStream} for details.
 """
 self.parent.send(obj)
 
 
 
 class XMPPHandlerCollection(object):
 """
 Collection of XMPP subprotocol handlers.
 
 This allows for grouping of subprotocol handlers, but is not an
 L{XMPPHandler} itself, so this is not recursive.
 
 @ivar handlers: List of protocol handlers.
 @type handlers: C{list} of objects providing
 L{IXMPPHandler}
 """
 
 implements(ijabber.IXMPPHandlerCollection)
 
 def __init__(self):
 self.handlers = []
 
 
 def __iter__(self):
 """
 Act as a container for handlers.
 """
 return iter(self.handlers)
 
 
 def addHandler(self, handler):
 """
 Add protocol handler.
 
 Protocol handlers are expected to provide L{ijabber.IXMPPHandler}.
 """
 self.handlers.append(handler)
 
 
 def removeHandler(self, handler):
 """
 Remove protocol handler.
 """
 self.handlers.remove(handler)
 
 
 
 class StreamManager(XMPPHandlerCollection):
 """
 Business logic representing a managed XMPP connection.
 
 This maintains a single XMPP connection and provides facilities for packet
 routing and transmission. Business logic modules are objects providing
 L{ijabber.IXMPPHandler} (like subclasses of L{XMPPHandler}), and added
 using L{addHandler}.
 
 @ivar xmlstream: currently managed XML stream
 @type xmlstream: L{XmlStream}
 @ivar logTraffic: if true, log all traffic.
 @type logTraffic: C{bool}
 @ivar _initialized: Whether the stream represented by L{xmlstream} has
 been initialized. This is used when caching outgoing
 stanzas.
 @type _initialized: C{bool}
 @ivar _packetQueue: internal buffer of unsent data. See L{send} for details.
 @type _packetQueue: C{list}
 """
 
 logTraffic = False
 
 def __init__(self, factory):
 XMPPHandlerCollection.__init__(self)
 self.xmlstream = None
 self._packetQueue = []
 self._initialized = False
 
 factory.addBootstrap(STREAM_CONNECTED_EVENT, self._connected)
 factory.addBootstrap(STREAM_AUTHD_EVENT, self._authd)
 factory.addBootstrap(INIT_FAILED_EVENT, self.initializationFailed)
 factory.addBootstrap(STREAM_END_EVENT, self._disconnected)
 self.factory = factory
 
 
 def addHandler(self, handler):
 """
 Add protocol handler.
 
 When an XML stream has already been established, the handler's
 C{connectionInitialized} will be called to get it up to speed.
 """
 XMPPHandlerCollection.addHandler(self, handler)
 
 # get protocol handler up to speed when a connection has already
 # been established
 if self.xmlstream and self._initialized:
 handler.makeConnection(self.xmlstream)
 handler.connectionInitialized()
 
 
 def _connected(self, xs):
 """
 Called when the transport connection has been established.
 
 Here we optionally set up traffic logging (depending on L{logTraffic})
 and call each handler's C{makeConnection} method with the L{XmlStream}
 instance.
 """
 def logDataIn(buf):
 log.msg("RECV: %r" % buf)
 
 def logDataOut(buf):
 log.msg("SEND: %r" % buf)
 
 if self.logTraffic:
 xs.rawDataInFn = logDataIn
 xs.rawDataOutFn = logDataOut
 
 self.xmlstream = xs
 
 for e in self:
 e.makeConnection(xs)
 
 
 def _authd(self, xs):
 """
 Called when the stream has been initialized.
 
 Send out cached stanzas and call each handler's
 C{connectionInitialized} method.
 """
 # Flush all pending packets
 for p in self._packetQueue:
 xs.send(p)
 self._packetQueue = []
 self._initialized = True
 
 # Notify all child services which implement
 # the IService interface
 for e in self:
 e.connectionInitialized()
 
 
 def initializationFailed(self, reason):
 """
 Called when stream initialization has failed.
 
 Stream initialization has halted, with the reason indicated by
 C{reason}. It may be retried by calling the authenticator's
 C{initializeStream}. See the respective authenticators for details.
 
 @param reason: A failure instance indicating why stream initialization
 failed.
 @type reason: L{failure.Failure}
 """
 
 
 def _disconnected(self, reason):
 """
 Called when the stream has been closed.
 
 From this point on, the manager doesn't interact with the
 L{XmlStream} anymore and notifies each handler that the connection
 was lost by calling its C{connectionLost} method.
 """
 self.xmlstream = None
 self._initialized = False
 
 # Notify all child services which implement
 # the IService interface
 for e in self:
 e.connectionLost(reason)
 
 
 def send(self, obj):
 """
 Send data over the XML stream.
 
 When there is no established XML stream, the data is queued and sent
 out when a new XML stream has been established and initialized.
 
 @param obj: data to be sent over the XML stream. See
 L{xmlstream.XmlStream.send} for details.
 """
 if self._initialized:
 self.xmlstream.send(obj)
 else:
 self._packetQueue.append(obj)
 
 
 
 __all__ = ['Authenticator', 'BaseFeatureInitiatingInitializer',
 'ConnectAuthenticator', 'FeatureNotAdvertized',
 'INIT_FAILED_EVENT', 'IQ', 'ListenAuthenticator', 'NS_STREAMS',
 'NS_XMPP_TLS', 'Reset', 'STREAM_AUTHD_EVENT',
 'STREAM_CONNECTED_EVENT', 'STREAM_END_EVENT', 'STREAM_ERROR_EVENT',
 'STREAM_START_EVENT', 'StreamManager', 'TLSError', 'TLSFailed',
 'TLSInitiatingInitializer', 'TLSNotSupported', 'TLSRequired',
 'TimeoutError', 'XMPPHandler', 'XMPPHandlerCollection', 'XmlStream',
 'XmlStreamFactory', 'XmlStreamServerFactory', 'hashPassword',
 'toResponse', 'upgradeWithIQResponseTracker']
 
 |