[Python-Dev] Let's make the SSL module sane (original) (raw)

Donald Stufft donald at stufft.io
Sat Sep 10 12:24:13 EDT 2016

On Sep 10, 2016, at 10:22 AM, Christian Heimes <christian at python.org> wrote:

I don't load any certs because it is not possible to remove a cert or X509 lookup once it is loaded. createdefaultcontext() just have to load the certs and set more secure ciper suites.

This part is the most concerning to me, though I understand why it’s the case. Perhaps we can do something a little tricky to allow both things to happen? IOW do sort of a late binding of a call to loading the default certificates if no other certificates has been loaded when the call to SSLContext().wrap_socket() has been made.

So we’d do something like:

class SSLContext: def init(self, …): self._loaded_certificates = False … # Do Other Stuff

def load_default_certs(self, …):
    self._loaded_certificates = True
    …  # Do Other Stuff

def load_verify_locations(self, …):
    self._loaded_certificates = True
    …  # Do Other Stuff

def wrap_socket(self, …):
    if not self._loaded_certificates:
        self.load_default_certs()

    …  # Do Other Stuff

That way if someone does something like:

ctx = ssl.SSLContext(ssl.PROTOCOL_TLS_CLIENT) ctx.load_verify_locations(cafile=“…”) ctx.wrap_socket(…)

Then they don’t get any default certificates added, HOWEVER if they do:

ctx = ssl.SSLContext(ssl.PROTOCOL_TLS_CLIENT) ctx.wrap_socket(…)

Then they do.

The main draw back I can see with this is that you can’t wrap a socket and then add certificates after the fact… but I don’t even know if that makes sense to do?

— Donald Stufft

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