otocols.tls import TLSMemoryBIOFactory
    from twisted.internet.protocol import ServerFactory
    from twisted.internet.ssl import PrivateCertificate
    from twisted.internet import reactor

    from someapplication import ApplicationProtocol

    serverFactory = ServerFactory()
    serverFactory.protocol = ApplicationProtocol
    certificate = PrivateCertificate.loadPEM(certPEMData)
    contextFactory = certificate.options()
    tlsFactory = TLSMemoryBIOFactory(contextFactory, False, serverFactory)
    reactor.listenTCP(12345, tlsFactory)
    reactor.run()

This API offers somewhat more flexibility than
L{twisted.internet.interfaces.IReactorSSL}; for example, a
L{TLSMemoryBIOProtocol} instance can use another instance of
L{TLSMemoryBIOProtocol} as its transport, yielding TLS over TLS - useful to
implement onion routing.  It can also be used to run TLS over unusual
transports, such as UNIX sockets and stdio.
é