Add embedded file signature verification.

mayan/apps/django_gpg/managers.py

@@ -10,7 +10,7 @@ import gnupg
 from django.db import models
 
 from .classes import KeyStub
-from .exceptions import KeyFetchingError
+from .exceptions import KeyDoesNotExist, KeyFetchingError
 from .literals import KEY_TYPE_PUBLIC, KEY_TYPE_SECRET
 from .settings import setting_gpg_path, setting_keyserver
 
@@ -62,3 +62,27 @@ class KeyManager(models.Manager):
 
     def private_keys(self):
         return self.filter(key_type=KEY_TYPE_SECRET)
+
+    def verify_file(self, file_object, signature_file=None):
+        temporary_directory = tempfile.mkdtemp()
+
+        gpg = gnupg.GPG(
+            gnupghome=temporary_directory, gpgbinary=setting_gpg_path.value
+        )
+
+        verify_result = gpg.verify_file(file=file_object)
+
+        if 'no public key' in verify_result.status:
+            # File is signed but we need the key for full verification
+            try:
+                key = self.get(fingerprint__endswith=verify_result.key_id)
+            except self.model.DoesNotExist:
+                raise KeyDoesNotExist('Signature key is not found in keyring')
+            else:
+                gpg.import_keys(key_data=key.key_data)
+                file_object.seek(0)
+                verify_result = gpg.verify_file(file=file_object)
+
+        shutil.rmtree(temporary_directory)
+
+        return verify_result

mayan/apps/django_gpg/migrations/0005_remove_key_key_id.py

@@ -1,7 +1,7 @@
 # -*- coding: utf-8 -*-
 from __future__ import unicode_literals
 
-from django.db import migrations, models
+from django.db import migrations
 
 
 class Migration(migrations.Migration):

mayan/apps/django_gpg/tests/literals.py

@@ -1,11 +1,8 @@
 from __future__ import unicode_literals
 
-TEST_GPG_HOME = '/tmp/test_gpg_home'
+import os
-TEST_KEY_FINGERPRINT = '6A24574E0A35004CDDFD22704125E9C571F378AC'
-TEST_KEYSERVERS = ['pool.sks-keyservers.net']
 
-TEST_SEARCH_UID = 'Roberto Rosario'
+from django.conf import settings
-TEST_SEARCH_FINGERPRINT = '607138F1AECC5A5CA31CB7715F3F7F75D210724D'
 
 TEST_KEY_DATA = '''-----BEGIN PGP PRIVATE KEY BLOCK-----
 Version: GnuPG v1
@@ -69,3 +66,14 @@ h4oCbUV5JHhOyB+89Y1w8haFU9LrgOER2kXff1xU6wMfLdcO5ApV/sRJcNdYL7Cg
 
 TEST_KEY_ID = '4125E9C571F378AC'
 TEST_KEY_FINGERPRINT = '6A24574E0A35004CDDFD22704125E9C571F378AC'
+TEST_KEY_PASSPHRASE = 'testpassphrase'
+
+TEST_KEYSERVERS = ['pool.sks-keyservers.net']
+
+TEST_SEARCH_UID = 'Roberto Rosario'
+TEST_SEARCH_FINGERPRINT = '607138F1AECC5A5CA31CB7715F3F7F75D210724D'
+
+TEST_SIGNED_FILE = os.path.join(
+    settings.BASE_DIR, 'mayan', 'apps', 'django_gpg', 'tests', 'contrib',
+    'test_files', 'test_file.txt.gpg'
+)

mayan/apps/django_gpg/tests/test_models.py

@@ -2,11 +2,12 @@ from __future__ import unicode_literals
 
 from django.test import TestCase
 
+from ..exceptions import KeyDoesNotExist
 from ..models import Key
 
 from .literals import (
     TEST_KEY_DATA, TEST_KEY_FINGERPRINT, TEST_SEARCH_FINGERPRINT,
-    TEST_SEARCH_UID
+    TEST_SEARCH_UID, TEST_SIGNED_FILE
 )
 
 
@@ -31,3 +32,17 @@ class KeyTestCase(TestCase):
 
         self.assertEqual(Key.objects.all().count(), 1)
         self.assertEqual(Key.objects.first().fingerprint, TEST_SEARCH_FINGERPRINT)
+
+    def test_embedded_verification_no_key(self):
+        with open(TEST_SIGNED_FILE) as signed_file:
+            with self.assertRaises(KeyDoesNotExist):
+                Key.objects.verify_file(signed_file)
+
+    def test_embedded_verification_with_key(self):
+        Key.objects.create(key_data=TEST_KEY_DATA)
+
+        with open(TEST_SIGNED_FILE) as signed_file:
+            result = Key.objects.verify_file(signed_file)
+
+        self.assertTrue(result)
+        self.assertEqual(result.fingerprint, TEST_KEY_FINGERPRINT)