Fix weak password hashing in Python and Django
==============================================

Install argon2-cffi and list django.contrib.auth.hashers.Argon2PasswordHasher
first in PASSWORD_HASHERS, keeping older hashers after it. Hash with
make_password() (or user.set_password()) and verify with
check_password(password, stored, setter): Django calls the setter after a
correct login when the hash is outdated, so you can save a new one. Never hash
passwords with hashlib.

Page: https://softwaresecurity.com/fix/password-hashing/python-django/

What is in this archive
-----------------------
password-hashing/python-django/   the project: three implementations of the same code and one test suite
  accounts/impl/vulnerable.py   (vulnerable)
  accounts/impl/fixed.py   (fixed)
  accounts/impl/wrong.py   (a plausible fix that still fails)
run-all.mjs   runs the tests in all three modes and checks the results (Node.js only)
LICENSE-CODE.txt

Run it
------
  Tested with CPython 3.14.8. run-all.mjs needs Node.js 22 or later. Supported
  versions: https://softwaresecurity.com/fix/versions/

  From the password-hashing/python-django folder, install the dependencies once
  (this needs network access):

    python3 -m venv .venv
    .venv/bin/python -m pip install -r requirements.txt

  Then run the tests. IMPL chooses the implementation the tests load:

    # every test passes
    IMPL=fixed .venv/bin/python -m pytest
    # an exploit test fails
    IMPL=vulnerable .venv/bin/python -m pytest
    # a test fails
    IMPL=wrong .venv/bin/python -m pytest

  The JUnit report is written to reports/junit.xml. To run all three modes and
  check the results in one step, run the harness from this top folder (it needs
  only Node.js; --install runs the install step first):

    node run-all.mjs --install password-hashing/python-django
    node run-all.mjs password-hashing/python-django

Verified
--------
  11 October 2026 on macOS 27.0 (Darwin 27.0.0, arm64), with python CPython
  3.14.8, django 6.1.2, argon2Cffi 25.1.0, argon2CffiBindings 26.1.0, pytest
  9.1.1, pytest-django 4.14.0, semgrep 1.180.0, bandit 1.9.4. Versions and
  results hold for that date: run the tests with your own versions before
  relying on the fix.

Licence
-------
  The code is MIT licensed (LICENSE-CODE.txt). The page text is CC BY 4.0.
