django-crypt

Symmetric encryption helper (Fernet) for Volkanos Django modules. Wraps cryptography.fernet with a salt loaded from settings.CRYPT_SALT.

Quick Start

Requires Python 3.11+.

make install   # uv venv + install deps
make test      # run tests
make lint      # ruff check + format

Usage

from django_crypt import Crypt

# Encrypt / decrypt
crypt = Crypt()                            # uses settings.CRYPT_SALT
encrypted = crypt.encrypt("secret value")
decrypted = crypt.decrypt(encrypted)
assert decrypted == "secret value"

# Generate fresh salt (for first-time setup)
salt = Crypt.generate_salt()               # static method
print(f"Save this in settings.CRYPT_SALT: {salt}")

Management Commands

python manage.py generate_salt           # generate fresh salt
python manage.py encrypt "plain text"    # encrypt a string
python manage.py decrypt "<ciphertext>"  # decrypt a string

Settings

# In Django settings.py
CRYPT_SALT = "<output of generate_salt>"
INSTALLED_APPS = [..., "django_crypt"]

Important

Fernet ciphertexts are non-deterministic — encrypting the same plaintext twice yields different ciphertexts. For deterministic lookup hashing (e.g. unique-indexed code lookup), use a separate HMAC-SHA256 helper, not Crypt.encrypt().

Details

See AGENTS.md for architecture and integration details.