AES crypto in pure Python?

[Paul Rubin]

andrew.fabbro at gmail.com writes:
> I'm looking for an implementation of AES (the Advanced Encryption
> Standard) in pure Python.  I'm aware of pycrypto, but that uses C code.
>  I'm hoping to find something that only uses Python...I'm willing to
> trade speed for portability, since my application is designed for
> several different platforms.
> 
> Anyone know if this has been done?

Yes, it's been done a few times, you should be able to find some with
a web search.  The ones I've seen are WAY too slow for most
applications, like a few blocks per second.  If you don't require
using AES, there are some alternatives possible, like using the
built-in sha module as the round function for a Feistel cipher, or
using it in OFB mode as a keystream generator.  I have some examples
of how to do either of these, if you want to see them.