Recommended Python cryptographic module?

cryptography, python

Solution

If you are in an environment which includes GnuPG and Python >= 2.4, then you could also consider a tool such as python-gnupg. (Disclaimer: I'm the maintainer of this project.) It leaves the heavy lifting to `gpg` and provides a fairly straightforward API.

Overview of API:

>>> import gnupg
>>> gpg = gnupg.GPG(gnupghome='/path/to/keyring/directory')
>>> gpg.list_keys()

[{
  ...
  'fingerprint': 'F819EE7705497D73E3CCEE65197D5DAC68F1AAB2',
  'keyid': '197D5DAC68F1AAB2',
  'length': '1024',
  'type': 'pub',
  'uids': ['', 'Gary Gross (A test user) ']},
 {
  ...
  'fingerprint': '37F24DD4B918CC264D4F31D60C5FEFA7A921FC4A',
  'keyid': '0C5FEFA7A921FC4A',
  'length': '1024',
  ...
  'uids': ['', 'Danny Davis (A test user) ']}]
>>> encrypted = gpg.encrypt("Hello, world!", ['0C5FEFA7A921FC4A'])
>>> str(encrypted)

'-----BEGIN PGP MESSAGE-----\nVersion: GnuPG v1.4.9 (GNU/Linux)\n
\nhQIOA/6NHMDTXUwcEAf
...
-----END PGP MESSAGE-----\n'
>>> decrypted = gpg.decrypt(str(encrypted), passphrase='secret')
>>> str(decrypted)
'Hello, world!'
>>> signed = gpg.sign("Goodbye, world!", passphrase='secret')
>>> verified = verified = gpg.verify(str(signed))
>>> print "Verified" if verified else "Not verified"

'Verified'

Problem

I've been exploring what cryptographic modules are available to Python, and I've found 3: ezPyCrypt, yawPyCrypt and KeyCzar (which actually supports a few languages, but Python is included amongst them). The first two rely on the PyCrypto module. Are there choices I am missing? Is there a clear front-runner for ease and features or does it simply come down to a manner of one's comfort level? I'm currently leaning towards KeyCzar, with ezPyCrypt close behind. I would be using the library for digital signature signing and verification, and potentially for key creation (although I won't cry if I have to make a call to something else for that functionality). I am using Python 3.x and have access to GPG.

Original source