mirror of
https://github.com/jazzband/django-fernet-encrypted-fields.git
synced 2026-03-16 22:40:27 +00:00
113 lines
3.1 KiB
Python
113 lines
3.1 KiB
Python
import base64
|
|
from django.conf import settings
|
|
from cryptography.fernet import Fernet, MultiFernet
|
|
from cryptography.hazmat.backends import default_backend
|
|
from cryptography.hazmat.primitives import hashes
|
|
from cryptography.hazmat.primitives.kdf.pbkdf2 import PBKDF2HMAC
|
|
from django.db import models
|
|
from django.utils.functional import cached_property
|
|
|
|
|
|
class EncryptedFieldMixin(object):
|
|
@cached_property
|
|
def keys(self):
|
|
keys = []
|
|
salt_keys = (
|
|
settings.SALT_KEY
|
|
if isinstance(settings.SALT_KEY, list)
|
|
else [settings.SALT_KEY]
|
|
)
|
|
for salt_key in salt_keys:
|
|
salt = bytes(salt_key, "utf-8")
|
|
kdf = PBKDF2HMAC(
|
|
algorithm=hashes.SHA256(),
|
|
length=32,
|
|
salt=salt,
|
|
iterations=100000,
|
|
backend=default_backend(),
|
|
)
|
|
keys.append(
|
|
base64.urlsafe_b64encode(
|
|
kdf.derive(settings.SECRET_KEY.encode("utf-8"))
|
|
)
|
|
)
|
|
return keys
|
|
|
|
@cached_property
|
|
def f(self):
|
|
if len(self.keys) == 1:
|
|
return Fernet(self.keys[0])
|
|
return MultiFernet([Fernet(k) for k in self.keys])
|
|
|
|
def get_internal_type(self):
|
|
"""
|
|
To treat everything as text
|
|
"""
|
|
return "TextField"
|
|
|
|
def get_prep_value(self, value):
|
|
if value:
|
|
if not isinstance(value, str):
|
|
value = str(value)
|
|
return self.f.encrypt(bytes(value, "utf-8")).decode("utf-8")
|
|
return None
|
|
|
|
def get_db_prep_value(self, value, connection, prepared=False):
|
|
if not prepared:
|
|
value = self.get_prep_value(value)
|
|
return value
|
|
|
|
def from_db_value(self, value, expression, connection):
|
|
return self.to_python(value)
|
|
|
|
def to_python(self, value):
|
|
if (
|
|
value is None
|
|
or not isinstance(value, str)
|
|
or hasattr(self, "_already_decrypted")
|
|
):
|
|
return value
|
|
value = self.f.decrypt(bytes(value, "utf-8")).decode("utf-8")
|
|
return super(EncryptedFieldMixin, self).to_python(value)
|
|
|
|
def clean(self, value, model_instance):
|
|
"""
|
|
Create and assign a semaphore so that to_python method will not try to decrypt an already decrypted value
|
|
during cleaning of a form
|
|
"""
|
|
self._already_decrypted = True
|
|
ret = super().clean(value, model_instance)
|
|
del self._already_decrypted
|
|
return ret
|
|
|
|
|
|
class EncryptedCharField(EncryptedFieldMixin, models.CharField):
|
|
pass
|
|
|
|
|
|
class EncryptedTextField(EncryptedFieldMixin, models.TextField):
|
|
pass
|
|
|
|
|
|
class EncryptedDateTimeField(EncryptedFieldMixin, models.DateTimeField):
|
|
pass
|
|
|
|
|
|
class EncryptedIntegerField(EncryptedFieldMixin, models.IntegerField):
|
|
pass
|
|
|
|
|
|
class EncryptedDateField(EncryptedFieldMixin, models.DateField):
|
|
pass
|
|
|
|
|
|
class EncryptedFloatField(EncryptedFieldMixin, models.FloatField):
|
|
pass
|
|
|
|
|
|
class EncryptedEmailField(EncryptedFieldMixin, models.EmailField):
|
|
pass
|
|
|
|
|
|
class EncryptedBooleanField(EncryptedFieldMixin, models.BooleanField):
|
|
pass
|