z3c.bcrypt 1.2

z3c.bcrypt

z3c.bcrypt provides zope.password compatible “password manager” utilities that use bcrypt (or alternatively pbkdf2) encoding for storing passwords.

Both encoding schemes are implemented in the cryptacular library that is a dependency for this pacakge.

z3c.bcrypt

>>> from zope.interface.verify import verifyObject
>>> from zope.password.interfaces import IPasswordManager
>>> from z3c.bcrypt import BcryptPasswordManager
>>> manager = BcryptPasswordManager()
>>> verifyObject(IPasswordManager, manager)
True

>>> password = u"right \N{CYRILLIC CAPITAL LETTER A}"

>>> encoded = manager.encodePassword(password)
>>> encoded
'$2a$...'
>>> manager.checkPassword(encoded, password)
True
>>> manager.checkPassword(encoded, password + u"wrong")
False

>>> from z3c.bcrypt import PBKDF2PasswordManager
>>> manager = PBKDF2PasswordManager()
>>> verifyObject(IPasswordManager, manager)
True

>>> encoded = manager.encodePassword(password)
>>> encoded
u'$p5k2$...'
>>> manager.checkPassword(encoded, password)
True
>>> manager.checkPassword(encoded, password + u"wrong")
False

>>> # A previously encoded password, should be decodable even if the
>>> # current encoding of the same password is different::
>>> previouslyencoded = (
...     '$p5k2$1000$LgAFPIlc9CgrlSaxHyTUMA='
...     '=$IuUYplhMkR4qCl8-ONRVjEgJNwE=')
>>> encoded == previouslyencoded
False
>>> manager.checkPassword(previouslyencoded , password)
True

Excessively long “passwords” will take up a lot of computation time that can be used as a DOS attack vector. The password managers in z3c.bcrypt will only use the first 4096 characters of the incoming password for checking.

This is inspired by:

https://www.djangoproject.com/weblog/2013/sep/15/security/

This test would take significantly longer if the 4096 length limit would not be in place. XXX how to test that reliably?

>>> incomming = '$p5k2$1000$' + 'a' * 1024 * 1024 * 100  # lot of data.
>>> manager.checkPassword(encoded, incomming)
False

Changelog of z3c.bcrypt