DSA module in Python

Question

Does anyone know of a pure DSA module in Python for signing messages?

Answer 1

Python Cryptography Toolkit has this module

Chilkat (this may be a pure module check with chilkat - commercially licensed )

Answer 2

If OpenSSL has the functionality you are looking for, try pyOpenSSL.

Answer 3

Unfortunately, you might have to use a wrapper to some non-Python implementation, like pyOpenSSL. I'm not aware of any pure Python crypto library that is secure.

In particular, pycrypto is a piece of crap. E.g., if you use DSA as proposed here by the author then the attack described in the paper "The Insecurity of the Digital Signature Algorithm with partially known nonces" by Nguyen and Shparlinski can be used to find the secret key very very fast. Note, that this paper has been presented in 2002, but pycrypto is still susceptible to it. Python is a really nice an friendly language for prototyping, but when it comes to defending against adversaries, it is a little too friendly.