text: """TLS Lite + asyncore."""
  
  
  import asyncore
  from gdata.tlslite.TLSConnection import TLSConnection
  from AsyncStateMachine import AsyncStateMachine
  
  
  class TLSAsyncDispatcherMixIn(AsyncStateMachine):
      """This class can be "mixed in" with an
      L{asyncore.dispatcher} to add TLS support.
  
      This class essentially sits between the dispatcher and the select
      loop, intercepting events and only calling the dispatcher when
      applicable.
  
      In the case of handle_read(), a read operation will be activated,
      and when it completes, the bytes will be placed in a buffer where
      the dispatcher can retrieve them by calling recv(), and the
      dispatcher's handle_read() will be called.
  
      In the case of handle_write(), the dispatcher's handle_write() will
      be called, and when it calls send(), a write operation will be
      activated.
  
      To use this class, you must combine it with an asyncore.dispatcher,
      and pass in a handshake operation with setServerHandshakeOp().
  
      Below is an example of using this class with medusa.  This class is
      mixed in with http_channel to create http_tls_channel.  Note:
       1. the mix-in is listed first in the inheritance list
  
       2. the input buffer size must be at least 16K, otherwise the
         dispatcher might not read all the bytes from the TLS layer,
         leaving some bytes in limbo.
  
       3. IE seems to have a problem receiving a whole HTTP response in a
       single TLS record, so HTML pages containing '\\r\\n\\r\\n' won't
       be displayed on IE.
  
      Add the following text into 'start_medusa.py', in the 'HTTP Server'
      section::
  
          from tlslite.api import *
          s = open("./serverX509Cert.pem").read()
          x509 = X509()
          x509.parse(s)
          certChain = X509CertChain([x509])
  
          s = open("./serverX509Key.pem").read()
          privateKey = parsePEMKey(s, private=True)
  
          class http_tls_channel(TLSAsyncDispatcherMixIn,
                                 http_server.http_channel):
              ac_in_buffer_size = 16384
  
              def __init__ (self, server, conn, addr):
                  http_server.http_channel.__init__(self, server, conn, addr)
                  TLSAsyncDispatcherMixIn.__init__(self, conn)
                  self.tlsConnection.ignoreAbruptClose = True
                  self.setServerHandshakeOp(certChain=certChain,
                                            privateKey=privateKey)
  
          hs.channel_class = http_tls_channel
  
      If the TLS layer raises an exception, the exception will be caught
      in asyncore.dispatcher, which will call close() on this class.  The
      TLS layer always closes the TLS connection before raising an
      exception, so the close operation will complete right away, causing
      asyncore.dispatcher.close() to be called, which closes the socket
      and removes this instance from the asyncore loop.
  
      """
  
  
      def __init__(self, sock=None):
          AsyncStateMachine.__init__(self)
  
          if sock:
              self.tlsConnection = TLSConnection(sock)
  
          #Calculate the sibling I'm being mixed in with.
          #This is necessary since we override functions
          #like readable(), handle_read(), etc., but we
          #also want to call the sibling's versions.
          for cl in self.__class__.__bases__:
              if cl != TLSAsyncDispatcherMixIn and cl != AsyncStateMachine:
                  self.siblingClass = cl
                  break
          else:
              raise AssertionError()
  
      def readable(self):
          result = self.wantsReadEvent()
          if result != None:
              return result
          return self.siblingClass.readable(self)
  
      def writable(self):
          result = self.wantsWriteEvent()
          if result != None:
              return result
          return self.siblingClass.writable(self)
  
      def handle_read(self):
          self.inReadEvent()
  
      def handle_write(self):
          self.inWriteEvent()
  
      def outConnectEvent(self):
          self.siblingClass.handle_connect(self)
  
      def outCloseEvent(self):
          asyncore.dispatcher.close(self)
  
      def outReadEvent(self, readBuffer):
          self.readBuffer = readBuffer
          self.siblingClass.handle_read(self)
  
      def outWriteEvent(self):
          self.siblingClass.handle_write(self)
  
      def recv(self, bufferSize=16384):
          if bufferSize < 16384 or self.readBuffer == None:
              raise AssertionError()
          returnValue = self.readBuffer
          self.readBuffer = None
          return returnValue
  
      def send(self, writeBuffer):
          self.setWriteOp(writeBuffer)
          return len(writeBuffer)
  
      def close(self):
          if hasattr(self, "tlsConnection"):
              self.setCloseOp()
          else:
              asyncore.dispatcher.close(self)
  