gistfile1.py

from OpenSSL import SSL
from twisted.internet import ssl


class TLSContextWithChainFileFactory(ssl.DefaultOpenSSLContextFactory):
    """
    A SSLContext factory for TLS only and C{certificateFileName} is set as the
    chain file.  Add all chain files that lead from the CA to your certificate.
    """
    def cacheContext(self):
        if self._context is None:
            ctx = SSL.Context(SSL.TLSv1_METHOD)
            ctx.use_certificate_chain_file(self.certificateFileName)
            ctx.use_privatekey_file(self.privateKeyFileName)
            self._context = ctx