python/vnc/extauth.py

   1 """
   2 Wrapper for Invirt VNC proxying
   3 """
   4
   5 # twisted imports
   6 from twisted.internet import reactor, protocol, defer
   7 from twisted.python import log
   8
   9 # python imports
  10 import sys
  11 import struct
  12 import string
  13 import cPickle
  14 # Python 2.5:
  15 #import hashlib
  16 import sha
  17 import hmac
  18 import base64
  19 import socket
  20 import time
  21
  22 def getTokenKey():
  23     token_key = file('/etc/invirt/secrets/vnc-key').read().strip()
  24     while True:
  25         yield token_key
  26 getTokenKey = getTokenKey().next
  27
  28 def getPort(name, auth_data):
  29     import get_port
  30     if (auth_data["machine"] == name):
  31         port = get_port.findPort(name)
  32         if port is None:
  33             return 0
  34         return int(port.split(':')[1])
  35     else:
  36         return None
  37
  38 class VNCAuthOutgoing(protocol.Protocol):
  39
  40     def __init__(self,socks):
  41         self.socks=socks
  42
  43     def connectionMade(self):
  44         peer = self.transport.getPeer()
  45         self.socks.makeReply(200)
  46         self.socks.otherConn=self
  47
  48     def connectionLost(self, reason):
  49         self.socks.transport.loseConnection()
  50
  51     def dataReceived(self,data):
  52         self.socks.write(data)
  53
  54     def write(self,data):
  55         self.transport.write(data)
  56
  57
  58 class VNCAuth(protocol.Protocol):
  59
  60     def __init__(self,server="localhost"):
  61         self.server=server
  62         self.auth=None
  63
  64     def connectionMade(self):
  65         self.buf=""
  66         self.otherConn=None
  67
  68     def validateToken(self, token):
  69         self.auth_error = "Invalid token"
  70         try:
  71             token = base64.urlsafe_b64decode(token)
  72             token = cPickle.loads(token)
  73             m = hmac.new(getTokenKey(), digestmod=sha)
  74             m.update(token['data'])
  75             if (m.digest() == token['digest']):
  76                 data = cPickle.loads(token['data'])
  77                 expires = data["expires"]
  78                 if (time.time() < expires):
  79                     self.auth = data["user"]
  80                     self.auth_error = None
  81                     self.auth_machine = data["machine"]
  82                     self.auth_data = data
  83                 else:
  84                     self.auth_error = "Token has expired; please try logging in again"
  85         except (TypeError, cPickle.UnpicklingError):
  86             self.auth = None
  87             print sys.exc_info()
  88
  89     def dataReceived(self,data):
  90         if self.otherConn:
  91             self.otherConn.write(data)
  92             return
  93         self.buf=self.buf+data
  94         if ('\r\n\r\n' in self.buf) or ('\n\n' in self.buf) or ('\r\r' in self.buf):
  95             lines = self.buf.splitlines()
  96             args = lines.pop(0).split()
  97             command = args.pop(0)
  98             headers = {}
  99             for line in lines:
 100                 try:
 101                     (header, data) = line.split(": ", 1)
 102                     headers[header] = data
 103                 except ValueError:
 104                     pass
 105
 106             if command == "AUTHTOKEN":
 107                 user = args[0]
 108                 token = headers["Auth-token"]
 109                 if token == "1": #FIXME
 110                     self.auth = user
 111                     self.makeReply(200, "Authentication successful")
 112                 else:
 113                     self.makeReply(401)
 114             elif command == "CONNECTVNC":
 115                 vmname = args[0]
 116                 if ("Auth-token" in headers):
 117                     token = headers["Auth-token"]
 118                     self.validateToken(token)
 119                     if self.auth is not None:
 120                         port = getPort(vmname, self.auth_data)
 121                         if port is not None: # FIXME
 122                             if port != 0:
 123                                 d = self.connectClass(self.server, port, VNCAuthOutgoing, self)
 124                                 d.addErrback(lambda result, self=self: self.makeReply(404, result.getErrorMessage()))
 125                             else:
 126                                 self.makeReply(404, "Unable to find VNC for VM "+vmname)
 127                         else:
 128                             self.makeReply(401, "Unauthorized to connect to VM "+vmname)
 129                     else:
 130                         if self.auth_error:
 131                             self.makeReply(401, self.auth_error)
 132                         else:
 133                             self.makeReply(401, "Invalid token")
 134                 else:
 135                     self.makeReply(401, "Login first")
 136             else:
 137                 self.makeReply(501, "unknown method "+command)
 138             self.buf=''
 139         if False and '\000' in self.buf[8:]:
 140             head,self.buf=self.buf[:8],self.buf[8:]
 141             try:
 142                 version,code,port=struct.unpack("!BBH",head[:4])
 143             except struct.error:
 144                 raise RuntimeError, "struct error with head='%s' and buf='%s'"%(repr(head),repr(self.buf))
 145             user,self.buf=string.split(self.buf,"\000",1)
 146             if head[4:7]=="\000\000\000": # domain is after
 147                 server,self.buf=string.split(self.buf,'\000',1)
 148                 #server=gethostbyname(server)
 149             else:
 150                 server=socket.inet_ntoa(head[4:8])
 151             assert version==4, "Bad version code: %s"%version
 152             if not self.authorize(code,server,port,user):
 153                 self.makeReply(91)
 154                 return
 155             if code==1: # CONNECT
 156                 d = self.connectClass(server, port, SOCKSv4Outgoing, self)
 157                 d.addErrback(lambda result, self=self: self.makeReply(91))
 158             else:
 159                 raise RuntimeError, "Bad Connect Code: %s" % code
 160             assert self.buf=="","hmm, still stuff in buffer... %s" % repr(self.buf)
 161
 162     def connectionLost(self, reason):
 163         if self.otherConn:
 164             self.otherConn.transport.loseConnection()
 165
 166     def authorize(self,code,server,port,user):
 167         log.msg("code %s connection to %s:%s (user %s) authorized" % (code,server,port,user))
 168         return 1
 169
 170     def connectClass(self, host, port, klass, *args):
 171         return protocol.ClientCreator(reactor, klass, *args).connectTCP(host,port)
 172
 173     def makeReply(self,reply,message=""):
 174         self.transport.write("VNCProxy/1.0 %d %s\r\n\r\n" % (reply, message))
 175         if int(reply / 100)!=2: self.transport.loseConnection()
 176
 177     def write(self,data):
 178         self.transport.write(data)
 179
 180     def log(self,proto,data):
 181         peer = self.transport.getPeer()
 182         their_peer = self.otherConn.transport.getPeer()
 183         print "%s\t%s:%d %s %s:%d\n"%(time.ctime(),
 184                                         peer.host,peer.port,
 185                                         ((proto==self and '<') or '>'),
 186                                         their_peer.host,their_peer.port),
 187         while data:
 188             p,data=data[:16],data[16:]
 189             print string.join(map(lambda x:'%02X'%ord(x),p),' ')+' ',
 190             print ((16-len(p))*3*' '),
 191             for c in p:
 192                 if len(repr(c))>3: print '.',
 193                 else: print c,
 194             print ""
 195         print ""
 196
 197
 198 class VNCAuthFactory(protocol.Factory):
 199     """A factory for a VNC auth proxy.
 200
 201     Constructor accepts one argument, a log file name.
 202     """
 203
 204     def __init__(self, server):
 205         self.server = server
 206
 207     def buildProtocol(self, addr):
 208         return VNCAuth(self.server)
 209