feat: #105 dedicated secret key for data encryption - Part 1

Author: payamnj

django_email_learning/models.py

@@ -5,6 +5,7 @@
 from django.conf import settings
 from django.db import models
 from django.core.validators import MaxValueValidator
+from django.core.exceptions import ImproperlyConfigured
 from cryptography.fernet import Fernet
 from cryptography.hazmat.primitives.kdf.pbkdf2 import PBKDF2HMAC
 from cryptography.hazmat.primitives import hashes
@@ -79,7 +80,13 @@ def _fernet(self) -> Fernet:
         kdf = PBKDF2HMAC(
             algorithm=hashes.SHA256(), length=32, salt=FIXED_SALT, iterations=100000
         )
-        key = base64.urlsafe_b64encode(kdf.derive(settings.SECRET_KEY.encode()))
+        try:
+            secret = settings.DJANGO_EMAIL_LEARNING["ENCRYPTION_SECRET_KEY"]
+        except (AttributeError, KeyError):
+            raise ImproperlyConfigured(
+                "DJANGO_EMAIL_LEARNING['ENCRYPTION_SECRET_KEY'] must be set in settings.py"
+            )
+        key = base64.urlsafe_b64encode(kdf.derive(secret.encode()))
         return Fernet(key)
 
     def _encrypt_password(self, password: str) -> str:

django_service/settings.py

@@ -98,6 +98,10 @@
     }
 }
 
+DJANGO_EMAIL_LEARNING = {
+    "ENCRYPTION_SECRET_KEY": "your-very-secure-and-random-key",
+}
+
 LOGGING = {
     "version": 1,
     "disable_existing_loggers": False,

tests/test_models/test_imap_connection.py

@@ -1,4 +1,5 @@
 from django_email_learning.models import ImapConnection
+from django.core.exceptions import ImproperlyConfigured
 import pytest
 
 
@@ -39,3 +40,29 @@ def test_imap_invalid_server_validation(invalid_server, imap_connection):
 def test_imap_valid_server_validation(valid_server, imap_connection):
     imap_connection.server = valid_server
     imap_connection.full_clean()  # Should not raise
+
+
+def test_raise_improperly_configured_if_django_email_learning_config_missing(
+    settings, db
+):
+    delattr(settings, "DJANGO_EMAIL_LEARNING")
+    with pytest.raises(ImproperlyConfigured):
+        ImapConnection.objects.create(
+            server="imap.example.com",
+            port=993,
+            email="user@example.com",
+            password="my_secret_password",
+            organization_id=1,
+        )
+
+
+def test_raise_improperly_configured_if_encryption_key_missing(settings, db):
+    settings.DJANGO_EMAIL_LEARNING = {}
+    with pytest.raises(ImproperlyConfigured):
+        ImapConnection.objects.create(
+            server="imap.example.com",
+            port=993,
+            email="user@example.com",
+            password="my_secret_password",
+            organization_id=1,
+        )