django-cryptographic-fields is set of fields that wrap standard Django
fields with encryption provided by the python cryptography library. These
fields are much more compatible with a 12-factor design since they take their
encryption key from the settings file instead of a file on disk used by
keyczar.
While keyczar is an excellent tool to use for encryption, it's not compatible with Python 3, and it requires, for hosts like Heroku, that you either check your key file into your git repository for deployment, or implement manual post-deployment processing to write the key stored in an environment variable into a file that keyczar can read.
$ pip install django-cryptographic-fields
Add "cryptographic_fields" to your INSTALLED_APPS setting like this:
- INSTALLED_APPS = (
- ... 'cryptographic_fields',
)
django-cryptographic-fields expects the encryption key to be specified
using FIELD_ENCRYPTION_KEY in your project's settings.py file. For
example, to load it from the local environment:
import os
FIELD_ENCRYPTION_KEY = os.environ.get('FIELD_ENCRYPTION_KEY', '')
To use an encrypted field in a Django model, use one of the fields from the
cryptographic_fields module:
from cryptographic_fields.fields import EncryptedCharField
- class EncryptedFieldModel(models.Model):
- encrypted_char_field = EncryptedCharField(max_length=100)
For fields that require max_length to be specified, the Encrypted
variants of those fields will automatically increase the size of the database
field to hold the encrypted form of the content. For example, a 3 character
CharField will automatically specify a database field size of 100 characters
when EncryptedCharField(max_length=3) is specified.
Due to the nature of the encrypted data, filtering by values contained in encrypted fields won't work properly. Sorting is also not supported.
There is a Django management command generate_encryption_key provided
with the cryptographic_fields library. Use this command to generate a new
encryption key to set as settings.FIELD_ENCRYPTION_KEY.
./manage.py generate_encryption_key
Running this command will print an encryption key to the terminal, which can be configured in your environment or settings file.