zxcvbn

|Build Status|

zxcvbn

A realistic password strength estimator.

This is a Python implementation of the library created by the team at Dropbox. The original library, written for JavaScript, can be found here <https://github.com/dropbox/zxcvbn>__.

While there may be other Python ports available, this one is the most up to date and is recommended by the original developers of zxcvbn at this time.

Features

• Tested in Python versions 3.8-3.13
• Accepts user data to be added to the dictionaries that are tested against (name, birthdate, etc)
• Gives a score to the password, from 0 (terrible) to 4 (great)
• Provides feedback on the password and ways to improve it
• Returns time estimates on how long it would take to guess the password in different situations

Installation

Install the package using pip: pip install zxcvbn

Usage

Pass a password as the first parameter, and a list of user-provided inputs as the user_inputs parameter (optional).

.. code:: python

from zxcvbn import zxcvbn

results = zxcvbn('JohnSmith123', user_inputs=['John', 'Smith'])

print(results)

Output:

::

{
    'password': 'JohnSmith123',
    'score': 2,
    'guesses': 2567800,
    'guesses_log10': 6.409561194521849,
    'calc_time': datetime.timedelta(0, 0, 5204)
    'feedback': {
        'warning': '',
        'suggestions': [
            'Add another word or two. Uncommon words are better.',
            "Capitalization doesn't help very much"
        ]
    },
    'crack_times_display': {
        'offline_fast_hashing_1e10_per_second': 'less than a second'
        'offline_slow_hashing_1e4_per_second': '4 minutes',
        'online_no_throttling_10_per_second': '3 days',
        'online_throttling_100_per_hour': '3 years',
    },
    'crack_times_seconds': {
        'offline_fast_hashing_1e10_per_second': 0.00025678,
        'offline_slow_hashing_1e4_per_second': 256.78
        'online_no_throttling_10_per_second': 256780.0,
        'online_throttling_100_per_hour': 92440800.0,
    },
    'sequence': [{
        'matched_word': 'john',
        'rank': 2,
        'pattern': 'dictionary',
        'reversed': False,
        'token': 'John',
        'l33t': False,
        'uppercase_variations': 2,
        'i': 0,
        'guesses': 50,
        'l33t_variations': 1,
        'dictionary_name': 'male_names',
        'base_guesses': 2,
        'guesses_log10': 1.6989700043360185,
        'j': 3
    }, {
        'matched_word': 'smith123',
        'rank': 12789,
        'pattern': 'dictionary',
        'reversed': False,
        'token': 'Smith123',
        'l33t': False,
        'uppercase_variations': 2,
        'i': 4,
        'guesses': 25578,
        'l33t_variations': 1,
        'dictionary_name': 'passwords',
        'base_guesses': 12789,
        'guesses_log10': 4.407866583030775,
        'j': 11
    }],
}

Another optional argument is max_length, allowing override of the default max password length of 72. .. code:: python

from zxcvbn import zxcvbn

results = zxcvbn('JohnSmith321', user_inputs=['John', 'Smith'], max_length=88)

.. warning::

We strongly advise against setting max_length greater than 72, as it can lead to long processing times and may leave server-side applications open to denial-of-service scenarios.

Custom Ranked Dictionaries

In order to support more languages or just add password dictionaries of your own, there is a helper function you may use.

.. code:: python

from zxcvbn.matching import add_frequency_lists

add_frequency_lists({
    'my_list': ['foo', 'bar'],
    'another_list': ['baz']
})

These lists will be added to the current ones, but you can also overwrite the current ones if you wish. The lists you add should be in order of how common the word is used with the most common words appearing first.

CLI

You an also use zxcvbn from the command line::

    echo 'password' | zxcvbn --user-input <user-input> | jq

You can include a ``--max-length`` argument::
    echo '<long password>' | zxcvbn --max-length 142

You can also execute the zxcvbn module::

    echo 'password' | python -m zxcvbn --user-input <user-input> | jq

Contribute
----------

- Report an Issue: https://github.com/dwolfhub/zxcvbn-python/issues
- Submit a Pull Request: https://github.com/dwolfhub/zxcvbn-python/pulls

License
-------

The project is licensed under the MIT license.


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