Fix get_prep_value and to_python function

encrypted_fields/fields.py

@@ -2,7 +2,7 @@ import base64
 from django.utils import timezone
 
 import warnings
-from cryptography.fernet import Fernet, MultiFernet
+from cryptography.fernet import Fernet, MultiFernet, InvalidToken
 from cryptography.hazmat.backends import default_backend
 from cryptography.hazmat.primitives import hashes
 from cryptography.hazmat.primitives.kdf.pbkdf2 import PBKDF2HMAC
@@ -49,6 +49,7 @@ class EncryptedFieldMixin(object):
         return "TextField"
 
     def get_prep_value(self, value):
+        value = super().get_prep_value(value)
         if value:
             if not isinstance(value, str):
                 value = str(value)
@@ -70,7 +71,12 @@ class EncryptedFieldMixin(object):
             or hasattr(self, "_already_decrypted")
         ):
             return value
-        value = self.f.decrypt(bytes(value, "utf-8")).decode("utf-8")
+        try:
+            value = self.f.decrypt(bytes(value, "utf-8")).decode("utf-8")
+        except InvalidToken:
+            pass
+        except UnicodeEncodeError:
+            pass
         return super(EncryptedFieldMixin, self).to_python(value)
 
     def clean(self, value, model_instance):
@@ -97,18 +103,6 @@ class EncryptedDateTimeField(EncryptedFieldMixin, models.DateTimeField):
 
 
 class EncryptedIntegerField(EncryptedFieldMixin, models.IntegerField):
-    def get_prep_value(self, value):
-        if value is None:
-            return None
-        try:
-            value = int(value)
-        except (TypeError, ValueError) as e:
-            raise e.__class__(
-                "Field '%s' expected a number but got %r." % (self.name, value),
-            ) from e
-        else:
-            return super().get_prep_value(value)
-
     @cached_property
     def validators(self):
         return [*self.default_validators, *self._validators]

package_test/tests.py

@@ -3,6 +3,7 @@ import re
 from django.db import connection
 from django.test import TestCase, override_settings
 from django.utils import timezone
+from django.core.exceptions import ValidationError
 
 from .models import TestModel
 
@@ -64,8 +65,9 @@ class FieldTest(TestCase):
 
         plaintext = "text"
 
-        model.datetime = plaintext
-        model.save()
+        with self.assertRaises(ValidationError):
+            model.datetime = plaintext
+            model.save()
 
     def test_integer_field_encrypted(self):
         plaintext = 42
@@ -103,8 +105,9 @@ class FieldTest(TestCase):
 
         plaintext = "text"
 
-        model.date = plaintext
-        model.save()
+        with self.assertRaises(ValidationError):
+            model.date = plaintext
+            model.save()
 
     def test_float_field_encrypted(self):
         plaintext = 42.44
@@ -123,8 +126,9 @@ class FieldTest(TestCase):
 
         plaintext = "text"
 
-        model.floating = plaintext
-        model.save()
+        with self.assertRaises(ValueError):
+            model.floating = plaintext
+            model.save()
 
     def test_email_field_encrypted(self):
         plaintext = "test@gmail.com"
@@ -168,8 +172,9 @@ class FieldTest(TestCase):
 
         plaintext = "text"
 
-        model.boolean = plaintext
-        model.save()
+        with self.assertRaises(ValidationError):
+            model.boolean = plaintext
+            model.save()
 
 
 class RotatedSaltTestCase(TestCase):