block ciphers

[Trevor Perrin]

(I know this has come up before, but the previous discussions I could 
find seemed inconclusive, so I hope people don't mind...)


Q: How about adding block ciphers to Python 2.4?

PEP 272 defines an API, and there's an excellent library that implements 
it [1].  It would be very little work to copy the AES and DES3 modules 
into stdlib (perhaps in a 'ciphers' package).

As far as legal issues, US Export is no problem - you just email in a 
notice [2].  A few countries have import issues, though I believe 
they're widely disregarded (the windows installer comes with SSL; has 
anyone complained?).  Furthermore, it would be easy to provide a 
no-crypto distribution.

It's hard to distribute pure-python crypto software without this.  You 
have to include or reference 3rd-party extension modules, which some 
users won't want to install, some will have trouble installing (like 
Windows users without a compiler), and some won't be able to install 
(Jython or IronPython users, for example).

So is this totally out of the question?  Or would it be worth pursuing, 
through a PEP, or patch, or discussion on python-dev?


Trevor


[1] http://www.amk.ca/python/code/crypto.html
[2] http://www.bxa.doc.gov/Encryption/PubAvailEncSourceCodeNofify.html