Fix anonymizers based on NumericFieldAnonymizer

.github/workflows/django.yml

@@ -12,8 +12,8 @@ jobs:
     strategy:
       max-parallel: 4
       matrix:
-        python-version: [3.11]
-        django-version: [Django~=4.2]
+        python-version: ["3.10", "3.11", "3.12", "3.13", "3.14"]
+        django-version: ["django~=4.2", "django~=5.1", "django~=5.2"]
 
     steps:
     - uses: actions/checkout@v2
@@ -24,8 +24,8 @@ jobs:
     - name: Install Dependencies
       run: |
         pip install ${{ matrix.django-version }}
-        python setup.py install
         pip install -r test_requirements.txt
+        pip install .
     - name: Run Tests
       run: |
         python runtests.py

gdpr/anonymizers/base.py

@@ -138,9 +138,14 @@ def __init__(self, max_anonymization_range: int = None, ignore_empty_values: boo
             self.max_anonymization_range = max_anonymization_range
         super().__init__(ignore_empty_values, empty_values)
 
-    def get_numeric_encryption_key(self, encryption_key: str, value: Union[int, float] = None) -> int:
+    def get_numeric_encryption_key(
+        self,
+        encryption_key: str,
+        value: Union[int, float] = None,
+        allow_zero: bool = True
+    ) -> int:
         """
-        From `encryption_key` create it's numeric counterpart of appropriate length.
+        From `encryption_key` create its numeric counterpart of appropriate length.
 
         If value is supplied then the appropriate length is based on it if not the
         parameter `self.max_anonymization_range` is used.
@@ -151,11 +156,18 @@ def get_numeric_encryption_key(self, encryption_key: str, value: Union[int, floa
 
         :param encryption_key: The encryption key generated by anonymizer.
         :param value: Value to which the result of this function will be used.
+        :param allow_zero: VWhether returning zero is permitted.
         :return: Numeric counterpart of encryption_key
         """
         if value is None:
             if self.max_anonymization_range is None:
-                return numerize_key(encryption_key)
-            return numerize_key(encryption_key) % self.max_anonymization_range
-
-        return numerize_key(encryption_key) % 10 ** get_number_guess_len(value)
+                numeric_key = numerize_key(encryption_key)
+            else:
+                numeric_key = numerize_key(encryption_key) % self.max_anonymization_range
+        else:
+            numeric_key = numerize_key(encryption_key) % (10 ** get_number_guess_len(value))
+
+        if numeric_key == 0 and not allow_zero:
+            return 1
+        else:
+            return numeric_key

gdpr/anonymizers/gis.py

@@ -1,4 +1,5 @@
 """Since django 1.11 djnago-GIS requires GDAL."""
+
 import logging
 from typing import Optional
 
@@ -50,18 +51,26 @@ def get_encrypted_value(self, value, encryption_key: str):
         from django.contrib.gis.geos import Point
 
         new_val: Point = Point(value.tuple)
-        new_val.x = (new_val.x + self.get_numeric_encryption_key(encryption_key, int(new_val.x))) % self.max_x_range
-        new_val.y = (new_val.y + self.get_numeric_encryption_key(encryption_key, int(new_val.y))) % self.max_y_range
+        new_val.x = (
+            new_val.x + self.get_numeric_encryption_key(encryption_key, int(new_val.x), allow_zero=False)
+        ) % self.max_x_range
+        new_val.y = (
+            new_val.y + self.get_numeric_encryption_key(encryption_key, int(new_val.y), allow_zero=False)
+        ) % self.max_y_range
 
         return new_val
 
     def get_decrypted_value(self, value, encryption_key: str):
         if not is_gis_installed():
-            raise ImproperlyConfigured('Unable to load django GIS.')
+            raise ImproperlyConfigured("Unable to load django GIS.")
         from django.contrib.gis.geos import Point
 
         new_val: Point = Point(value.tuple)
-        new_val.x = (new_val.x - self.get_numeric_encryption_key(encryption_key, int(new_val.x))) % self.max_x_range
-        new_val.y = (new_val.y - self.get_numeric_encryption_key(encryption_key, int(new_val.y))) % self.max_y_range
+        new_val.x = (
+            new_val.x - self.get_numeric_encryption_key(encryption_key, int(new_val.x), allow_zero=False)
+        ) % self.max_x_range
+        new_val.y = (
+            new_val.y - self.get_numeric_encryption_key(encryption_key, int(new_val.y), allow_zero=False)
+        ) % self.max_y_range
 
         return new_val

gdpr/anonymizers/local/cs.py

@@ -345,7 +345,7 @@ def get_encrypted_value(self, value, encryption_key: str):
         account = CzechAccountNumber.parse(value)
 
         if self.use_smart_method and account.check_account_format():
-            return str(account.brute_force_next(self.get_numeric_encryption_key(encryption_key)))
+            return str(account.brute_force_next(self.get_numeric_encryption_key(encryption_key, allow_zero=False)))
 
         account.num = int(encrypt_text(encryption_key, str(account.num), NUMBERS))
 
@@ -355,7 +355,7 @@ def get_decrypted_value(self, value: Any, encryption_key: str):
         account = CzechAccountNumber.parse(value)
 
         if self.use_smart_method and account.check_account_format():
-            return str(account.brute_force_prev(self.get_numeric_encryption_key(encryption_key)))
+            return str(account.brute_force_prev(self.get_numeric_encryption_key(encryption_key, allow_zero=False)))
 
         account.num = int(decrypt_text(encryption_key, str(account.num), NUMBERS))
 
@@ -369,13 +369,13 @@ def get_encrypted_value(self, value: Any, encryption_key: str):
         iban = CzechIBAN.parse(value)
         if not iban.check_iban_format():
             raise ValidationError(f'IBAN \'{value}\' does not appear to be valid czech IBAN.')
-        return str(iban.brute_force_next(self.get_numeric_encryption_key(encryption_key)))
+        return str(iban.brute_force_next(self.get_numeric_encryption_key(encryption_key, allow_zero=False)))
 
     def get_decrypted_value(self, value: Any, encryption_key: str):
         iban = CzechIBAN.parse(value)
         if not iban.check_iban_format():
             raise ValidationError(f'IBAN \'{value}\' does not appear to be valid czech IBAN.')
-        return str(iban.brute_force_prev(self.get_numeric_encryption_key(encryption_key)))
+        return str(iban.brute_force_prev(self.get_numeric_encryption_key(encryption_key, allow_zero=False)))
 
 
 class CzechPhoneNumberFieldAnonymizer(FieldAnonymizer):

gdpr/migrations/0002_auto_20180509_1518.py

@@ -5,7 +5,6 @@
 import datetime
 
 from django.db import migrations, models
-from django.utils.timezone import utc
 
 
 class Migration(migrations.Migration):
@@ -22,8 +21,10 @@ class Migration(migrations.Migration):
         migrations.AddField(
             model_name='legalreason',
             name='issued_at',
-            field=models.DateTimeField(default=datetime.datetime(2018, 5, 9, 13, 18, 7, 317147, tzinfo=utc),
-                                       verbose_name='issued at'),
+            field=models.DateTimeField(
+                default=datetime.datetime(2018, 5, 9, 13, 18, 7, 317147, tzinfo=datetime.timezone.utc),
+                verbose_name='issued at'
+            ),
             preserve_default=False,
         ),
         migrations.AlterField(

gdpr/tests/test_cs_fields.py

@@ -13,6 +13,7 @@ class TestCzechAccountNumberField(TestCase):
     def setUpTestData(cls):
         cls.field = CzechAccountNumberFieldAnonymizer()
         cls.encryption_key = 'LoremIpsumDolorSitAmet'
+        cls.zero_remainder_encryption_key = 'Vu'
 
     def test_account_number_simple_field(self):
         account_number = '2501277007/2010'
@@ -35,6 +36,17 @@ def test_account_number_simple_field_smart_method(self):
 
         assert_equal(out_decrypt, account_number)
 
+    def test_account_number_simple_field_smart_method_using_encryption_key_having_zero_modulo_remainder(self):
+        field = CzechAccountNumberFieldAnonymizer(use_smart_method=True)
+        account_number = '2501277007/2010'
+        out = field.get_encrypted_value(account_number, self.zero_remainder_encryption_key)
+
+        assert_not_equal(out, account_number)
+
+        out_decrypt = field.get_decrypted_value(out, self.zero_remainder_encryption_key)
+
+        assert_equal(out_decrypt, account_number)
+
     def test_account_number_with_pre_num_field(self):
         account_number = '19-2000145399/0800'
         out = self.field.get_encrypted_value(account_number, self.encryption_key)
@@ -79,6 +91,7 @@ class TestCzechIBANSmartFieldAnonymizer(TestCase):
     def setUpTestData(cls):
         cls.field = CzechIBANSmartFieldAnonymizer()
         cls.encryption_key = 'LoremIpsumDolorSitAmet'
+        cls.zero_remainder_encryption_key = 'Vu'
         cls.text_iban = 'CZ65 0800 0000 1920 0014 5399'
         cls.no_space_text_iban = 'CZ6508000000192000145399'
         cls.invalid_text_iban = 'CZ00 0800 0000 1920 0014 5399'
@@ -91,6 +104,13 @@ def test_czech_iban_field(self):
         out_decrypted = self.field.get_decrypted_value(out, self.encryption_key)
         assert_equal(out_decrypted, self.text_iban)
 
+    def test_czech_iban_field_using_encryption_key_having_zero_modulo_remainder(self):
+        out = self.field.get_encrypted_value(self.text_iban, self.zero_remainder_encryption_key)
+        assert_not_equal(out, self.text_iban)
+
+        out_decrypted = self.field.get_decrypted_value(out, self.zero_remainder_encryption_key)
+        assert_equal(out_decrypted, self.text_iban)
+
     def test_czech_iban_field_no_space(self):
         out = self.field.get_encrypted_value(self.no_space_text_iban, self.encryption_key)
         assert_not_equal(out, self.no_space_text_iban)

setup.py

@@ -24,22 +24,24 @@ def read(fname):
     classifiers=[
         'Development Status :: 3 - Alpha',
         'Framework :: Django',
-        'Framework :: Django :: 1.10',
-        'Framework :: Django :: 1.11',
-        'Framework :: Django :: 2.0',
-        'Framework :: Django :: 2.1',
+        'Framework :: Django :: 4.2',
+        'Framework :: Django :: 5.1',
+        'Framework :: Django :: 5.2',
         'Intended Audience :: Developers',
         'License :: OSI Approved :: MIT License',
         'Operating System :: OS Independent',
         'Programming Language :: Python',
-        'Programming Language :: Python :: 3.6',
-        'Programming Language :: Python :: 3.7',
+        'Programming Language :: Python :: 3.10',
+        'Programming Language :: Python :: 3.11',
+        'Programming Language :: Python :: 3.12',
+        'Programming Language :: Python :: 3.13',
+        'Programming Language :: Python :: 3.14',
         'Programming Language :: Python :: 3 :: Only',
-        'Intended Audience :: Developers',
         'Topic :: Internet :: WWW/HTTP :: Dynamic Content',
     ],
+    python_requires='>=3.10',
     install_requires=[
-        'django>=4.2',
+        'django>=4.2,<6',
         'skip-django-chamber>=0.7.2',
         'tqdm>=4.28.1',
         'pyaes>=1.6.1',

test_requirements.txt

@@ -2,7 +2,8 @@ flake8==3.8.4
 mypy==0.991
 python-dateutil==2.7.5
 django-extensions
-freezegun==0.3.12
+freezegun
 Faker==1.0.1
-skip-django-germanium==2.4.0
+skip-django-germanium==2.6.0
 django-auditlog
+setuptools