>From the TUF perspective it seems like it would be straightforward to make the MOTD a "package", whose "contents" is the MOTD text, and that we "upgrade" it to get the latest text before displaying anything.
-n On Thu, Apr 12, 2018, 05:10 Nick Coghlan <ncogh...@gmail.com> wrote: > On 12 April 2018 at 07:01, Paul Moore <p.f.mo...@gmail.com> wrote: > > HTTPS access to the index server is fundamental to pip - if an > > attacker can subvert that, they don't need to mess with a message, > > they can just replace packages. So I don't see that displaying a > > message that's available from that same index server is an additional > > vulnerability, surely? But I'm not a security expert - I'd defer to > > someone like Donald to comment on the security aspects of any proposal > > here. > > Right now it doesn't create any additional vulnerabilities, since > we're relying primarily on HTTPS for PyPI -> installer security. > > However, that changes once PEP 458 gets implemented, as that will > switch the primary package level security mechanism over to TUF, which > includes a range of mechanisms designed to detect tampering with the > link to PyPI (including freeze attacks that keep you from checking for > new packages, or attempting to lie about which versions are > available). > > So the scenario we want to avoid is one where an attacker can present > a notice that says "Please ignore that scary security warning your > installer is giving you, we're having an issue with the metadata > generation process on the server. To resolve the problem, please force > upgrade pip". > > That's a solvable problem (e.g. only check for the MOTD *after* > successfully retrieving a valid metadata file), but it's still > something to take into account. > > Cheers, > Nick. > > -- > Nick Coghlan | ncogh...@gmail.com | Brisbane, Australia > _______________________________________________ > Distutils-SIG maillist - Distutils-SIG@python.org > https://mail.python.org/mailman/listinfo/distutils-sig >
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