[Python-Dev] [ssl] The weird case of IDNA (original) (raw)

Nathaniel Smith njs at pobox.com
Sun Dec 31 12:07:01 EST 2017

On Dec 31, 2017 7:37 AM, "Stephen J. Turnbull" < turnbull.stephen.fw at u.tsukuba.ac.jp> wrote:

Nathaniel Smith writes:

Issue 1: Python's built-in IDNA implementation is wrong (implements IDNA 2003, not IDNA 2008).

Is "wrong" the right word here? I'll grant you that 2008 is better, but typically in practice versions coexist for years. Ie, is there no backward compatibility issue with registries that specified IDNA 2003?

Well, yeah, I was simplifying, but at the least we can say that always and only using IDNA 2003 certainly isn't right :-). I think in most cases the preferred way to deal with these kinds of issues is not to carry around an IDNA 2003 implementation, but instead to use an IDNA 2008 implementation with the "transitional compatibility" flag enabled in the UTS46 preprocessor? But this is rapidly exceeding my knowledge.

This is another reason why we ought to let users do their own IDNA handling if they want...

This is not entirely an idle question: I'd like to tool up on the RFCs, research existing practice (especially in the East/Southeast Asian registries), and contribute to the implementation if there may be an issue remaining. (Interpreting RFCs is something I'm reasonably good at.)

Maybe this is a good place to start:

https://github.com/kjd/idna/blob/master/README.rst

-n

[Sorry if my quoting is messed up; posting from my phone and Gmail for Android apparently generates broken text/plain.] -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://mail.python.org/pipermail/python-dev/attachments/20171231/c5625fd3/attachment.html>

More information about the Python-Dev mailing list