openvpn: Function to detect ECC/RSA configuration

Signed-off-by: Joseph Nuthalapati <njoseph@riseup.net>
Reviewed-by: James Valleroy <jvalleroy@mailbox.org>

plinth/modules/openvpn/__init__.py

@@ -3,6 +3,8 @@
 FreedomBox app to configure OpenVPN server.
 """
 
+import os
+
 from django.urls import reverse_lazy
 from django.utils.translation import ugettext_lazy as _
 
@@ -36,6 +38,8 @@ app = None
 
 setup_process = None
 
+SERVER_CONFIGURATION_FILE = '/etc/openvpn/server/freedombox.conf'
+
 
 class OpenVPNApp(app_module.App):
     """FreedomBox app for OpenVPN."""
@@ -100,3 +104,13 @@ def setup(helper, old_version=None):
 def is_setup():
     """Return whether the service is running."""
     return actions.superuser_run('openvpn', ['is-setup']).strip() == 'true'
+
+
+def is_using_ecc():
+    """Return whether the service is using RSA."""
+    if os.path.exists(SERVER_CONFIGURATION_FILE):
+        with open(SERVER_CONFIGURATION_FILE, 'r') as file_handle:
+            for line in file_handle:
+                if line.strip() == 'dh none':
+                    return True
+    return False

plinth/modules/openvpn/tests/test_configuration.py

@@ -0,0 +1,32 @@
+# SPDX-License-Identifier: AGPL-3.0-or-later
+"""
+Test module for OpenVPN configuration.
+"""
+
+from unittest.mock import patch
+
+import pytest
+
+from plinth.modules import openvpn
+
+
+@pytest.fixture(name='conf_file')
+def fixture_conf_file(tmp_path):
+    """Fixture that returns an empty configuration file."""
+    return str(tmp_path / 'freedombox.conf')
+
+
+def test_identify_rsa_configuration(conf_file):
+    """Identify RSA configuration based on configuration file."""
+    with patch('plinth.modules.openvpn.SERVER_CONFIGURATION_FILE', conf_file):
+        with open(conf_file, 'w') as file_handle:
+            file_handle.write('dh /etc/openvpn/freedombox-keys/pki/dh.pem')
+        assert not openvpn.is_using_ecc()
+
+
+def test_identify_ecc_configuration(conf_file):
+    """Identify ECC configuration based on configuration file."""
+    with patch('plinth.modules.openvpn.SERVER_CONFIGURATION_FILE', conf_file):
+        with open(conf_file, 'w') as file_handle:
+            file_handle.write('dh none')
+        assert openvpn.is_using_ecc()