[Twisted-Python] Twisted + tlslite

[Trevor Perrin]

At 05:40 AM 3/7/2004 +0000, exarkun at divmod.com wrote:

>On Fri, 05 Mar 2004 22:33:48 -0800, Trevor Perrin <trevp at trevp.net> wrote:
> > [...]
> > I recently wrote an SSL library in python [1] and got it working with
> > asyncore.  I'd like to make it useable with Twisted too.[...]
>[...]
>   One tip: don't try to integrate with the existing SSL code.  The 
> implementation is very much a result of the API limitations of 
> PyOpenSSL.  Preferably, a new implementation will provide SSL support as 
> a protocol instead of a transport.  For examples of how this can be done, 
> see twisted.protocols.policies.


Hi JP,

thanks for the tip!  I've got a first-draft done and it seems to work 
pretty well.

One thing I'm not sure about is exception handling.  When TLS Lite throws 
an exception, is there anywhere I can plug-in a handler or something?

The code is at http://trevp.net/tlslite/, if anyone's curious.  Below is an 
example of using it.  Echo1 does a TLS handshake when the client connects, 
and Echo2 does a handshake when the client sends "STARTTLS".

class Echo(LineReceiver):
     def connectionMade(self):
         self.transport.write("Welcome to the echo server!\r\n")

     def lineReceived(self, line):
         self.transport.write(line + "\r\n")

class Echo1(Echo):
     def connectionMade(self):
         if not self.transport.tlsStarted:
             self.transport.setServerHandshakeOp(certChain=certChain,
                                                 privateKey=privateKey)
         else:
             Echo.connectionMade(self)

class Echo2(Echo):
     def lineReceived(self, data):
         if data == "STARTTLS":
             self.transport.setServerHandshakeOp(certChain=certChain,
                                                 privateKey=privateKey)
         else:
             Echo.lineReceived(self, data)

factory = Factory()
factory.protocol = Echo1
#factory.protocol = Echo2

wrappingFactory = WrappingFactory(factory)
wrappingFactory.protocol = tlslite.TLSTwistedProtocolWrapper


Trevor