Can anyone suggest a good crypto package?

[Fett]

I need a crypto package that works on windows with python 2.5. Can
anyone suggest one for me?

I have been searching for a couple days for a good cryptography
package to use for public/private key encryption, at this point I
would settle for symmetric even.

Every encryption package I have found for python was either operating
system specific (read *nix only):
http://www.freenet.org.nz/ezPyCrypto/
http://www.keyczar.org/

There was one exception, this version was specifically built to run on
any platform (yay), but the compiler for windows complained that I
wasn't using python2.2 (though the package was said to only need 2.2
or newer).

Is there any crypto package that is actually written in python? I
seriously don't care how slow it is.