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openmedialibrary_platform/Darwin/lib/python2.7/site-packages/twisted/protocols/sip.py

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Open Media Library Platform
2013-10-11 17:28:32 +00:00
# -*- test-case-name: twisted.test.test_sip -*-
# Copyright (c) Twisted Matrix Laboratories.
# See LICENSE for details.
"""Session Initialization Protocol.
Documented in RFC 2543.
[Superceded by 3261]
This module contains a deprecated implementation of HTTP Digest authentication.
See L{twisted.cred.credentials} and L{twisted.cred._digest} for its new home.
"""
# system imports
import socket, time, sys, random, warnings
from hashlib import md5
from zope.interface import implements, Interface
# twisted imports
from twisted.python import log, util
from twisted.python.deprecate import deprecated
from twisted.python.versions import Version
from twisted.internet import protocol, defer, reactor
from twisted import cred
import twisted.cred.error
from twisted.cred.credentials import UsernameHashedPassword, UsernamePassword
# sibling imports
from twisted.protocols import basic
PORT = 5060
# SIP headers have short forms
shortHeaders = {"call-id": "i",
"contact": "m",
"content-encoding": "e",
"content-length": "l",
"content-type": "c",
"from": "f",
"subject": "s",
"to": "t",
"via": "v",
}
longHeaders = {}
for k, v in shortHeaders.items():
longHeaders[v] = k
del k, v
statusCodes = {
100: "Trying",
180: "Ringing",
181: "Call Is Being Forwarded",
182: "Queued",
183: "Session Progress",
200: "OK",
300: "Multiple Choices",
301: "Moved Permanently",
302: "Moved Temporarily",
303: "See Other",
305: "Use Proxy",
380: "Alternative Service",
400: "Bad Request",
401: "Unauthorized",
402: "Payment Required",
403: "Forbidden",
404: "Not Found",
405: "Method Not Allowed",
406: "Not Acceptable",
407: "Proxy Authentication Required",
408: "Request Timeout",
409: "Conflict", # Not in RFC3261
410: "Gone",
411: "Length Required", # Not in RFC3261
413: "Request Entity Too Large",
414: "Request-URI Too Large",
415: "Unsupported Media Type",
416: "Unsupported URI Scheme",
420: "Bad Extension",
421: "Extension Required",
423: "Interval Too Brief",
480: "Temporarily Unavailable",
481: "Call/Transaction Does Not Exist",
482: "Loop Detected",
483: "Too Many Hops",
484: "Address Incomplete",
485: "Ambiguous",
486: "Busy Here",
487: "Request Terminated",
488: "Not Acceptable Here",
491: "Request Pending",
493: "Undecipherable",
500: "Internal Server Error",
501: "Not Implemented",
502: "Bad Gateway", # no donut
503: "Service Unavailable",
504: "Server Time-out",
505: "SIP Version not supported",
513: "Message Too Large",
600: "Busy Everywhere",
603: "Decline",
604: "Does not exist anywhere",
606: "Not Acceptable",
}
specialCases = {
'cseq': 'CSeq',
'call-id': 'Call-ID',
'www-authenticate': 'WWW-Authenticate',
}
def dashCapitalize(s):
''' Capitalize a string, making sure to treat - as a word seperator '''
return '-'.join([ x.capitalize() for x in s.split('-')])
def unq(s):
if s[0] == s[-1] == '"':
return s[1:-1]
return s
def DigestCalcHA1(
pszAlg,
pszUserName,
pszRealm,
pszPassword,
pszNonce,
pszCNonce,
):
m = md5()
m.update(pszUserName)
m.update(":")
m.update(pszRealm)
m.update(":")
m.update(pszPassword)
HA1 = m.digest()
if pszAlg == "md5-sess":
m = md5()
m.update(HA1)
m.update(":")
m.update(pszNonce)
m.update(":")
m.update(pszCNonce)
HA1 = m.digest()
return HA1.encode('hex')
DigestCalcHA1 = deprecated(Version("Twisted", 9, 0, 0))(DigestCalcHA1)
def DigestCalcResponse(
HA1,
pszNonce,
pszNonceCount,
pszCNonce,
pszQop,
pszMethod,
pszDigestUri,
pszHEntity,
):
m = md5()
m.update(pszMethod)
m.update(":")
m.update(pszDigestUri)
if pszQop == "auth-int":
m.update(":")
m.update(pszHEntity)
HA2 = m.digest().encode('hex')
m = md5()
m.update(HA1)
m.update(":")
m.update(pszNonce)
m.update(":")
if pszNonceCount and pszCNonce: # pszQop:
m.update(pszNonceCount)
m.update(":")
m.update(pszCNonce)
m.update(":")
m.update(pszQop)
m.update(":")
m.update(HA2)
hash = m.digest().encode('hex')
return hash
DigestCalcResponse = deprecated(Version("Twisted", 9, 0, 0))(DigestCalcResponse)
_absent = object()
class Via(object):
"""
A L{Via} is a SIP Via header, representing a segment of the path taken by
the request.
See RFC 3261, sections 8.1.1.7, 18.2.2, and 20.42.
@ivar transport: Network protocol used for this leg. (Probably either "TCP"
or "UDP".)
@type transport: C{str}
@ivar branch: Unique identifier for this request.
@type branch: C{str}
@ivar host: Hostname or IP for this leg.
@type host: C{str}
@ivar port: Port used for this leg.
@type port C{int}, or None.
@ivar rportRequested: Whether to request RFC 3581 client processing or not.
@type rportRequested: C{bool}
@ivar rportValue: Servers wishing to honor requests for RFC 3581 processing
should set this parameter to the source port the request was received
from.
@type rportValue: C{int}, or None.
@ivar ttl: Time-to-live for requests on multicast paths.
@type ttl: C{int}, or None.
@ivar maddr: The destination multicast address, if any.
@type maddr: C{str}, or None.
@ivar hidden: Obsolete in SIP 2.0.
@type hidden: C{bool}
@ivar otherParams: Any other parameters in the header.
@type otherParams: C{dict}
"""
def __init__(self, host, port=PORT, transport="UDP", ttl=None,
hidden=False, received=None, rport=_absent, branch=None,
maddr=None, **kw):
"""
Set parameters of this Via header. All arguments correspond to
attributes of the same name.
To maintain compatibility with old SIP
code, the 'rport' argument is used to determine the values of
C{rportRequested} and C{rportValue}. If None, C{rportRequested} is set
to True. (The deprecated method for doing this is to pass True.) If an
integer, C{rportValue} is set to the given value.
Any arguments not explicitly named here are collected into the
C{otherParams} dict.
"""
self.transport = transport
self.host = host
self.port = port
self.ttl = ttl
self.hidden = hidden
self.received = received
if rport is True:
warnings.warn(
"rport=True is deprecated since Twisted 9.0.",
DeprecationWarning,
stacklevel=2)
self.rportValue = None
self.rportRequested = True
elif rport is None:
self.rportValue = None
self.rportRequested = True
elif rport is _absent:
self.rportValue = None
self.rportRequested = False
else:
self.rportValue = rport
self.rportRequested = False
self.branch = branch
self.maddr = maddr
self.otherParams = kw
def _getrport(self):
"""
Returns the rport value expected by the old SIP code.
"""
if self.rportRequested == True:
return True
elif self.rportValue is not None:
return self.rportValue
else:
return None
def _setrport(self, newRPort):
"""
L{Base._fixupNAT} sets C{rport} directly, so this method sets
C{rportValue} based on that.
@param newRPort: The new rport value.
@type newRPort: C{int}
"""
self.rportValue = newRPort
self.rportRequested = False
rport = property(_getrport, _setrport)
def toString(self):
"""
Serialize this header for use in a request or response.
"""
s = "SIP/2.0/%s %s:%s" % (self.transport, self.host, self.port)
if self.hidden:
s += ";hidden"
for n in "ttl", "branch", "maddr", "received":
value = getattr(self, n)
if value is not None:
s += ";%s=%s" % (n, value)
if self.rportRequested:
s += ";rport"
elif self.rportValue is not None:
s += ";rport=%s" % (self.rport,)
etc = self.otherParams.items()
etc.sort()
for k, v in etc:
if v is None:
s += ";" + k
else:
s += ";%s=%s" % (k, v)
return s
def parseViaHeader(value):
"""
Parse a Via header.
@return: The parsed version of this header.
@rtype: L{Via}
"""
parts = value.split(";")
sent, params = parts[0], parts[1:]
protocolinfo, by = sent.split(" ", 1)
by = by.strip()
result = {}
pname, pversion, transport = protocolinfo.split("/")
if pname != "SIP" or pversion != "2.0":
raise ValueError, "wrong protocol or version: %r" % value
result["transport"] = transport
if ":" in by:
host, port = by.split(":")
result["port"] = int(port)
result["host"] = host
else:
result["host"] = by
for p in params:
# it's the comment-striping dance!
p = p.strip().split(" ", 1)
if len(p) == 1:
p, comment = p[0], ""
else:
p, comment = p
if p == "hidden":
result["hidden"] = True
continue
parts = p.split("=", 1)
if len(parts) == 1:
name, value = parts[0], None
else:
name, value = parts
if name in ("rport", "ttl"):
value = int(value)
result[name] = value
return Via(**result)
class URL:
"""A SIP URL."""
def __init__(self, host, username=None, password=None, port=None,
transport=None, usertype=None, method=None,
ttl=None, maddr=None, tag=None, other=None, headers=None):
self.username = username
self.host = host
self.password = password
self.port = port
self.transport = transport
self.usertype = usertype
self.method = method
self.tag = tag
self.ttl = ttl
self.maddr = maddr
if other == None:
self.other = []
else:
self.other = other
if headers == None:
self.headers = {}
else:
self.headers = headers
def toString(self):
l = []; w = l.append
w("sip:")
if self.username != None:
w(self.username)
if self.password != None:
w(":%s" % self.password)
w("@")
w(self.host)
if self.port != None:
w(":%d" % self.port)
if self.usertype != None:
w(";user=%s" % self.usertype)
for n in ("transport", "ttl", "maddr", "method", "tag"):
v = getattr(self, n)
if v != None:
w(";%s=%s" % (n, v))
for v in self.other:
w(";%s" % v)
if self.headers:
w("?")
w("&".join([("%s=%s" % (specialCases.get(h) or dashCapitalize(h), v)) for (h, v) in self.headers.items()]))
return "".join(l)
def __str__(self):
return self.toString()
def __repr__(self):
return '<URL %s:%s@%s:%r/%s>' % (self.username, self.password, self.host, self.port, self.transport)
def parseURL(url, host=None, port=None):
"""Return string into URL object.
URIs are of of form 'sip:user@example.com'.
"""
d = {}
if not url.startswith("sip:"):
raise ValueError("unsupported scheme: " + url[:4])
parts = url[4:].split(";")
userdomain, params = parts[0], parts[1:]
udparts = userdomain.split("@", 1)
if len(udparts) == 2:
userpass, hostport = udparts
upparts = userpass.split(":", 1)
if len(upparts) == 1:
d["username"] = upparts[0]
else:
d["username"] = upparts[0]
d["password"] = upparts[1]
else:
hostport = udparts[0]
hpparts = hostport.split(":", 1)
if len(hpparts) == 1:
d["host"] = hpparts[0]
else:
d["host"] = hpparts[0]
d["port"] = int(hpparts[1])
if host != None:
d["host"] = host
if port != None:
d["port"] = port
for p in params:
if p == params[-1] and "?" in p:
d["headers"] = h = {}
p, headers = p.split("?", 1)
for header in headers.split("&"):
k, v = header.split("=")
h[k] = v
nv = p.split("=", 1)
if len(nv) == 1:
d.setdefault("other", []).append(p)
continue
name, value = nv
if name == "user":
d["usertype"] = value
elif name in ("transport", "ttl", "maddr", "method", "tag"):
if name == "ttl":
value = int(value)
d[name] = value
else:
d.setdefault("other", []).append(p)
return URL(**d)
def cleanRequestURL(url):
"""Clean a URL from a Request line."""
url.transport = None
url.maddr = None
url.ttl = None
url.headers = {}
def parseAddress(address, host=None, port=None, clean=0):
"""Return (name, uri, params) for From/To/Contact header.
@param clean: remove unnecessary info, usually for From and To headers.
"""
address = address.strip()
# simple 'sip:foo' case
if address.startswith("sip:"):
return "", parseURL(address, host=host, port=port), {}
params = {}
name, url = address.split("<", 1)
name = name.strip()
if name.startswith('"'):
name = name[1:]
if name.endswith('"'):
name = name[:-1]
url, paramstring = url.split(">", 1)
url = parseURL(url, host=host, port=port)
paramstring = paramstring.strip()
if paramstring:
for l in paramstring.split(";"):
if not l:
continue
k, v = l.split("=")
params[k] = v
if clean:
# rfc 2543 6.21
url.ttl = None
url.headers = {}
url.transport = None
url.maddr = None
return name, url, params
class SIPError(Exception):
def __init__(self, code, phrase=None):
if phrase is None:
phrase = statusCodes[code]
Exception.__init__(self, "SIP error (%d): %s" % (code, phrase))
self.code = code
self.phrase = phrase
class RegistrationError(SIPError):
"""Registration was not possible."""
class Message:
"""A SIP message."""
length = None
def __init__(self):
self.headers = util.OrderedDict() # map name to list of values
self.body = ""
self.finished = 0
def addHeader(self, name, value):
name = name.lower()
name = longHeaders.get(name, name)
if name == "content-length":
self.length = int(value)
self.headers.setdefault(name,[]).append(value)
def bodyDataReceived(self, data):
self.body += data
def creationFinished(self):
if (self.length != None) and (self.length != len(self.body)):
raise ValueError, "wrong body length"
self.finished = 1
def toString(self):
s = "%s\r\n" % self._getHeaderLine()
for n, vs in self.headers.items():
for v in vs:
s += "%s: %s\r\n" % (specialCases.get(n) or dashCapitalize(n), v)
s += "\r\n"
s += self.body
return s
def _getHeaderLine(self):
raise NotImplementedError
class Request(Message):
"""A Request for a URI"""
def __init__(self, method, uri, version="SIP/2.0"):
Message.__init__(self)
self.method = method
if isinstance(uri, URL):
self.uri = uri
else:
self.uri = parseURL(uri)
cleanRequestURL(self.uri)
def __repr__(self):
return "<SIP Request %d:%s %s>" % (id(self), self.method, self.uri.toString())
def _getHeaderLine(self):
return "%s %s SIP/2.0" % (self.method, self.uri.toString())
class Response(Message):
"""A Response to a URI Request"""
def __init__(self, code, phrase=None, version="SIP/2.0"):
Message.__init__(self)
self.code = code
if phrase == None:
phrase = statusCodes[code]
self.phrase = phrase
def __repr__(self):
return "<SIP Response %d:%s>" % (id(self), self.code)
def _getHeaderLine(self):
return "SIP/2.0 %s %s" % (self.code, self.phrase)
class MessagesParser(basic.LineReceiver):
"""A SIP messages parser.
Expects dataReceived, dataDone repeatedly,
in that order. Shouldn't be connected to actual transport.
"""
version = "SIP/2.0"
acceptResponses = 1
acceptRequests = 1
state = "firstline" # or "headers", "body" or "invalid"
debug = 0
def __init__(self, messageReceivedCallback):
self.messageReceived = messageReceivedCallback
self.reset()
def reset(self, remainingData=""):
self.state = "firstline"
self.length = None # body length
self.bodyReceived = 0 # how much of the body we received
self.message = None
self.header = None
self.setLineMode(remainingData)
def invalidMessage(self):
self.state = "invalid"
self.setRawMode()
def dataDone(self):
# clear out any buffered data that may be hanging around
self.clearLineBuffer()
if self.state == "firstline":
return
if self.state != "body":
self.reset()
return
if self.length == None:
# no content-length header, so end of data signals message done
self.messageDone()
elif self.length < self.bodyReceived:
# aborted in the middle
self.reset()
else:
# we have enough data and message wasn't finished? something is wrong
raise RuntimeError, "this should never happen"
def dataReceived(self, data):
try:
basic.LineReceiver.dataReceived(self, data)
except:
log.err()
self.invalidMessage()
def handleFirstLine(self, line):
"""Expected to create self.message."""
raise NotImplementedError
def lineLengthExceeded(self, line):
self.invalidMessage()
def lineReceived(self, line):
if self.state == "firstline":
while line.startswith("\n") or line.startswith("\r"):
line = line[1:]
if not line:
return
try:
a, b, c = line.split(" ", 2)
except ValueError:
self.invalidMessage()
return
if a == "SIP/2.0" and self.acceptResponses:
# response
try:
code = int(b)
except ValueError:
self.invalidMessage()
return
self.message = Response(code, c)
elif c == "SIP/2.0" and self.acceptRequests:
self.message = Request(a, b)
else:
self.invalidMessage()
return
self.state = "headers"
return
else:
assert self.state == "headers"
if line:
# multiline header
if line.startswith(" ") or line.startswith("\t"):
name, value = self.header
self.header = name, (value + line.lstrip())
else:
# new header
if self.header:
self.message.addHeader(*self.header)
self.header = None
try:
name, value = line.split(":", 1)
except ValueError:
self.invalidMessage()
return
self.header = name, value.lstrip()
# XXX we assume content-length won't be multiline
if name.lower() == "content-length":
try:
self.length = int(value.lstrip())
except ValueError:
self.invalidMessage()
return
else:
# CRLF, we now have message body until self.length bytes,
# or if no length was given, until there is no more data
# from the connection sending us data.
self.state = "body"
if self.header:
self.message.addHeader(*self.header)
self.header = None
if self.length == 0:
self.messageDone()
return
self.setRawMode()
def messageDone(self, remainingData=""):
assert self.state == "body"
self.message.creationFinished()
self.messageReceived(self.message)
self.reset(remainingData)
def rawDataReceived(self, data):
assert self.state in ("body", "invalid")
if self.state == "invalid":
return
if self.length == None:
self.message.bodyDataReceived(data)
else:
dataLen = len(data)
expectedLen = self.length - self.bodyReceived
if dataLen > expectedLen:
self.message.bodyDataReceived(data[:expectedLen])
self.messageDone(data[expectedLen:])
return
else:
self.bodyReceived += dataLen
self.message.bodyDataReceived(data)
if self.bodyReceived == self.length:
self.messageDone()
class Base(protocol.DatagramProtocol):
"""Base class for SIP clients and servers."""
PORT = PORT
debug = False
def __init__(self):
self.messages = []
self.parser = MessagesParser(self.addMessage)
def addMessage(self, msg):
self.messages.append(msg)
def datagramReceived(self, data, addr):
self.parser.dataReceived(data)
self.parser.dataDone()
for m in self.messages:
self._fixupNAT(m, addr)
if self.debug:
log.msg("Received %r from %r" % (m.toString(), addr))
if isinstance(m, Request):
self.handle_request(m, addr)
else:
self.handle_response(m, addr)
self.messages[:] = []
def _fixupNAT(self, message, (srcHost, srcPort)):
# RFC 2543 6.40.2,
senderVia = parseViaHeader(message.headers["via"][0])
if senderVia.host != srcHost:
senderVia.received = srcHost
if senderVia.port != srcPort:
senderVia.rport = srcPort
message.headers["via"][0] = senderVia.toString()
elif senderVia.rport == True:
senderVia.received = srcHost
senderVia.rport = srcPort
message.headers["via"][0] = senderVia.toString()
def deliverResponse(self, responseMessage):
"""Deliver response.
Destination is based on topmost Via header."""
destVia = parseViaHeader(responseMessage.headers["via"][0])
# XXX we don't do multicast yet
host = destVia.received or destVia.host
port = destVia.rport or destVia.port or self.PORT
destAddr = URL(host=host, port=port)
self.sendMessage(destAddr, responseMessage)
def responseFromRequest(self, code, request):
"""Create a response to a request message."""
response = Response(code)
for name in ("via", "to", "from", "call-id", "cseq"):
response.headers[name] = request.headers.get(name, [])[:]
return response
def sendMessage(self, destURL, message):
"""Send a message.
@param destURL: C{URL}. This should be a *physical* URL, not a logical one.
@param message: The message to send.
"""
if destURL.transport not in ("udp", None):
raise RuntimeError, "only UDP currently supported"
if self.debug:
log.msg("Sending %r to %r" % (message.toString(), destURL))
self.transport.write(message.toString(), (destURL.host, destURL.port or self.PORT))
def handle_request(self, message, addr):
"""Override to define behavior for requests received
@type message: C{Message}
@type addr: C{tuple}
"""
raise NotImplementedError
def handle_response(self, message, addr):
"""Override to define behavior for responses received.
@type message: C{Message}
@type addr: C{tuple}
"""
raise NotImplementedError
class IContact(Interface):
"""A user of a registrar or proxy"""
class Registration:
def __init__(self, secondsToExpiry, contactURL):
self.secondsToExpiry = secondsToExpiry
self.contactURL = contactURL
class IRegistry(Interface):
"""Allows registration of logical->physical URL mapping."""
def registerAddress(domainURL, logicalURL, physicalURL):
"""Register the physical address of a logical URL.
@return: Deferred of C{Registration} or failure with RegistrationError.
"""
def unregisterAddress(domainURL, logicalURL, physicalURL):
"""Unregister the physical address of a logical URL.
@return: Deferred of C{Registration} or failure with RegistrationError.
"""
def getRegistrationInfo(logicalURL):
"""Get registration info for logical URL.
@return: Deferred of C{Registration} object or failure of LookupError.
"""
class ILocator(Interface):
"""Allow looking up physical address for logical URL."""
def getAddress(logicalURL):
"""Return physical URL of server for logical URL of user.
@param logicalURL: a logical C{URL}.
@return: Deferred which becomes URL or fails with LookupError.
"""
class Proxy(Base):
"""SIP proxy."""
PORT = PORT
locator = None # object implementing ILocator
def __init__(self, host=None, port=PORT):
"""Create new instance.
@param host: our hostname/IP as set in Via headers.
@param port: our port as set in Via headers.
"""
self.host = host or socket.getfqdn()
self.port = port
Base.__init__(self)
def getVia(self):
"""Return value of Via header for this proxy."""
return Via(host=self.host, port=self.port)
def handle_request(self, message, addr):
# send immediate 100/trying message before processing
#self.deliverResponse(self.responseFromRequest(100, message))
f = getattr(self, "handle_%s_request" % message.method, None)
if f is None:
f = self.handle_request_default
try:
d = f(message, addr)
except SIPError, e:
self.deliverResponse(self.responseFromRequest(e.code, message))
except:
log.err()
self.deliverResponse(self.responseFromRequest(500, message))
else:
if d is not None:
d.addErrback(lambda e:
self.deliverResponse(self.responseFromRequest(e.code, message))
)
def handle_request_default(self, message, (srcHost, srcPort)):
"""Default request handler.
Default behaviour for OPTIONS and unknown methods for proxies
is to forward message on to the client.
Since at the moment we are stateless proxy, thats basically
everything.
"""
def _mungContactHeader(uri, message):
message.headers['contact'][0] = uri.toString()
return self.sendMessage(uri, message)
viaHeader = self.getVia()
if viaHeader.toString() in message.headers["via"]:
# must be a loop, so drop message
log.msg("Dropping looped message.")
return
message.headers["via"].insert(0, viaHeader.toString())
name, uri, tags = parseAddress(message.headers["to"][0], clean=1)
# this is broken and needs refactoring to use cred
d = self.locator.getAddress(uri)
d.addCallback(self.sendMessage, message)
d.addErrback(self._cantForwardRequest, message)
def _cantForwardRequest(self, error, message):
error.trap(LookupError)
del message.headers["via"][0] # this'll be us
self.deliverResponse(self.responseFromRequest(404, message))
def deliverResponse(self, responseMessage):
"""Deliver response.
Destination is based on topmost Via header."""
destVia = parseViaHeader(responseMessage.headers["via"][0])
# XXX we don't do multicast yet
host = destVia.received or destVia.host
port = destVia.rport or destVia.port or self.PORT
destAddr = URL(host=host, port=port)
self.sendMessage(destAddr, responseMessage)
def responseFromRequest(self, code, request):
"""Create a response to a request message."""
response = Response(code)
for name in ("via", "to", "from", "call-id", "cseq"):
response.headers[name] = request.headers.get(name, [])[:]
return response
def handle_response(self, message, addr):
"""Default response handler."""
v = parseViaHeader(message.headers["via"][0])
if (v.host, v.port) != (self.host, self.port):
# we got a message not intended for us?
# XXX note this check breaks if we have multiple external IPs
# yay for suck protocols
log.msg("Dropping incorrectly addressed message")
return
del message.headers["via"][0]
if not message.headers["via"]:
# this message is addressed to us
self.gotResponse(message, addr)
return
self.deliverResponse(message)
def gotResponse(self, message, addr):
"""Called with responses that are addressed at this server."""
pass
class IAuthorizer(Interface):
def getChallenge(peer):
"""Generate a challenge the client may respond to.
@type peer: C{tuple}
@param peer: The client's address
@rtype: C{str}
@return: The challenge string
"""
def decode(response):
"""Create a credentials object from the given response.
@type response: C{str}
"""
class BasicAuthorizer:
"""Authorizer for insecure Basic (base64-encoded plaintext) authentication.
This form of authentication is broken and insecure. Do not use it.
"""
implements(IAuthorizer)
def __init__(self):
"""
This method exists solely to issue a deprecation warning.
"""
warnings.warn(
"twisted.protocols.sip.BasicAuthorizer was deprecated "
"in Twisted 9.0.0",
category=DeprecationWarning,
stacklevel=2)
def getChallenge(self, peer):
return None
def decode(self, response):
# At least one SIP client improperly pads its Base64 encoded messages
for i in range(3):
try:
creds = (response + ('=' * i)).decode('base64')
except:
pass
else:
break
else:
# Totally bogus
raise SIPError(400)
p = creds.split(':', 1)
if len(p) == 2:
return UsernamePassword(*p)
raise SIPError(400)
class DigestedCredentials(UsernameHashedPassword):
"""Yet Another Simple Digest-MD5 authentication scheme"""
def __init__(self, username, fields, challenges):
warnings.warn(
"twisted.protocols.sip.DigestedCredentials was deprecated "
"in Twisted 9.0.0",
category=DeprecationWarning,
stacklevel=2)
self.username = username
self.fields = fields
self.challenges = challenges
def checkPassword(self, password):
method = 'REGISTER'
response = self.fields.get('response')
uri = self.fields.get('uri')
nonce = self.fields.get('nonce')
cnonce = self.fields.get('cnonce')
nc = self.fields.get('nc')
algo = self.fields.get('algorithm', 'MD5')
qop = self.fields.get('qop-options', 'auth')
opaque = self.fields.get('opaque')
if opaque not in self.challenges:
return False
del self.challenges[opaque]
user, domain = self.username.split('@', 1)
if uri is None:
uri = 'sip:' + domain
expected = DigestCalcResponse(
DigestCalcHA1(algo, user, domain, password, nonce, cnonce),
nonce, nc, cnonce, qop, method, uri, None,
)
return expected == response
class DigestAuthorizer:
CHALLENGE_LIFETIME = 15
implements(IAuthorizer)
def __init__(self):
warnings.warn(
"twisted.protocols.sip.DigestAuthorizer was deprecated "
"in Twisted 9.0.0",
category=DeprecationWarning,
stacklevel=2)
self.outstanding = {}
def generateNonce(self):
c = tuple([random.randrange(sys.maxint) for _ in range(3)])
c = '%d%d%d' % c
return c
def generateOpaque(self):
return str(random.randrange(sys.maxint))
def getChallenge(self, peer):
c = self.generateNonce()
o = self.generateOpaque()
self.outstanding[o] = c
return ','.join((
'nonce="%s"' % c,
'opaque="%s"' % o,
'qop-options="auth"',
'algorithm="MD5"',
))
def decode(self, response):
response = ' '.join(response.splitlines())
parts = response.split(',')
auth = dict([(k.strip(), unq(v.strip())) for (k, v) in [p.split('=', 1) for p in parts]])
try:
username = auth['username']
except KeyError:
raise SIPError(401)
try:
return DigestedCredentials(username, auth, self.outstanding)
except:
raise SIPError(400)
class RegisterProxy(Proxy):
"""A proxy that allows registration for a specific domain.
Unregistered users won't be handled.
"""
portal = None
registry = None # should implement IRegistry
authorizers = {}
def __init__(self, *args, **kw):
Proxy.__init__(self, *args, **kw)
self.liveChallenges = {}
if "digest" not in self.authorizers:
self.authorizers["digest"] = DigestAuthorizer()
def handle_ACK_request(self, message, (host, port)):
# XXX
# ACKs are a client's way of indicating they got the last message
# Responding to them is not a good idea.
# However, we should keep track of terminal messages and re-transmit
# if no ACK is received.
pass
def handle_REGISTER_request(self, message, (host, port)):
"""Handle a registration request.
Currently registration is not proxied.
"""
if self.portal is None:
# There is no portal. Let anyone in.
self.register(message, host, port)
else:
# There is a portal. Check for credentials.
if not message.headers.has_key("authorization"):
return self.unauthorized(message, host, port)
else:
return self.login(message, host, port)
def unauthorized(self, message, host, port):
m = self.responseFromRequest(401, message)
for (scheme, auth) in self.authorizers.iteritems():
chal = auth.getChallenge((host, port))
if chal is None:
value = '%s realm="%s"' % (scheme.title(), self.host)
else:
value = '%s %s,realm="%s"' % (scheme.title(), chal, self.host)
m.headers.setdefault('www-authenticate', []).append(value)
self.deliverResponse(m)
def login(self, message, host, port):
parts = message.headers['authorization'][0].split(None, 1)
a = self.authorizers.get(parts[0].lower())
if a:
try:
c = a.decode(parts[1])
except SIPError:
raise
except:
log.err()
self.deliverResponse(self.responseFromRequest(500, message))
else:
c.username += '@' + self.host
self.portal.login(c, None, IContact
).addCallback(self._cbLogin, message, host, port
).addErrback(self._ebLogin, message, host, port
).addErrback(log.err
)
else:
self.deliverResponse(self.responseFromRequest(501, message))
def _cbLogin(self, (i, a, l), message, host, port):
# It's stateless, matey. What a joke.
self.register(message, host, port)
def _ebLogin(self, failure, message, host, port):
failure.trap(cred.error.UnauthorizedLogin)
self.unauthorized(message, host, port)
def register(self, message, host, port):
"""Allow all users to register"""
name, toURL, params = parseAddress(message.headers["to"][0], clean=1)
contact = None
if message.headers.has_key("contact"):
contact = message.headers["contact"][0]
if message.headers.get("expires", [None])[0] == "0":
self.unregister(message, toURL, contact)
else:
# XXX Check expires on appropriate URL, and pass it to registry
# instead of having registry hardcode it.
if contact is not None:
name, contactURL, params = parseAddress(contact, host=host, port=port)
d = self.registry.registerAddress(message.uri, toURL, contactURL)
else:
d = self.registry.getRegistrationInfo(toURL)
d.addCallbacks(self._cbRegister, self._ebRegister,
callbackArgs=(message,),
errbackArgs=(message,)
)
def _cbRegister(self, registration, message):
response = self.responseFromRequest(200, message)
if registration.contactURL != None:
response.addHeader("contact", registration.contactURL.toString())
response.addHeader("expires", "%d" % registration.secondsToExpiry)
response.addHeader("content-length", "0")
self.deliverResponse(response)
def _ebRegister(self, error, message):
error.trap(RegistrationError, LookupError)
# XXX return error message, and alter tests to deal with
# this, currently tests assume no message sent on failure
def unregister(self, message, toURL, contact):
try:
expires = int(message.headers["expires"][0])
except ValueError:
self.deliverResponse(self.responseFromRequest(400, message))
else:
if expires == 0:
if contact == "*":
contactURL = "*"
else:
name, contactURL, params = parseAddress(contact)
d = self.registry.unregisterAddress(message.uri, toURL, contactURL)
d.addCallback(self._cbUnregister, message
).addErrback(self._ebUnregister, message
)
def _cbUnregister(self, registration, message):
msg = self.responseFromRequest(200, message)
msg.headers.setdefault('contact', []).append(registration.contactURL.toString())
msg.addHeader("expires", "0")
self.deliverResponse(msg)
def _ebUnregister(self, registration, message):
pass
class InMemoryRegistry:
"""A simplistic registry for a specific domain."""
implements(IRegistry, ILocator)
def __init__(self, domain):
self.domain = domain # the domain we handle registration for
self.users = {} # map username to (IDelayedCall for expiry, address URI)
def getAddress(self, userURI):
if userURI.host != self.domain:
return defer.fail(LookupError("unknown domain"))
if userURI.username in self.users:
dc, url = self.users[userURI.username]
return defer.succeed(url)
else:
return defer.fail(LookupError("no such user"))
def getRegistrationInfo(self, userURI):
if userURI.host != self.domain:
return defer.fail(LookupError("unknown domain"))
if self.users.has_key(userURI.username):
dc, url = self.users[userURI.username]
return defer.succeed(Registration(int(dc.getTime() - time.time()), url))
else:
return defer.fail(LookupError("no such user"))
def _expireRegistration(self, username):
try:
dc, url = self.users[username]
except KeyError:
return defer.fail(LookupError("no such user"))
else:
dc.cancel()
del self.users[username]
return defer.succeed(Registration(0, url))
def registerAddress(self, domainURL, logicalURL, physicalURL):
if domainURL.host != self.domain:
log.msg("Registration for domain we don't handle.")
return defer.fail(RegistrationError(404))
if logicalURL.host != self.domain:
log.msg("Registration for domain we don't handle.")
return defer.fail(RegistrationError(404))
if logicalURL.username in self.users:
dc, old = self.users[logicalURL.username]
dc.reset(3600)
else:
dc = reactor.callLater(3600, self._expireRegistration, logicalURL.username)
log.msg("Registered %s at %s" % (logicalURL.toString(), physicalURL.toString()))
self.users[logicalURL.username] = (dc, physicalURL)
return defer.succeed(Registration(int(dc.getTime() - time.time()), physicalURL))
def unregisterAddress(self, domainURL, logicalURL, physicalURL):
return self._expireRegistration(logicalURL.username)
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