[feat] set fetched keys as Weak Chain if they are not from the same domain

Nicknym server is authoritative for its own domain, but for others it might
retrieve keys from key servers. On keys from the same domain we set the
validation level to 'Provider Trust'. For other domains in the email
address we set it to 'Weak Chain' as we don't have info about its source.

Resolves: #6815
Related: #6718
Releases: 0.4.0

1 files changed, 39 insertions, 1 deletions

diff --git a/src/leap/keymanager/__init__.py b/src/leap/keymanager/__init__.py
index 3ef63505..f7b19747 100644
--- a/src/leap/keymanager/__init__.py
+++ b/src/leap/keymanager/__init__.py
@@ -44,6 +44,7 @@ import logging
 import requests
 
 from twisted.internet import defer
+from urlparse import urlparse
 
 from leap.common.check import leap_assert
 from leap.common.events import signal
@@ -219,13 +220,21 @@ class KeyManager(object):
             res = self._get(self._nickserver_uri, {'address': address})
             res.raise_for_status()
             server_keys = res.json()
+
             # insert keys in local database
             if self.OPENPGP_KEY in server_keys:
+                # nicknym server is authoritative for its own domain,
+                # for other domains the key might come from key servers.
+                validation_level = ValidationLevel.Weak_Chain
+                _, domain = _split_email(address)
+                if (domain == _get_domain(self._nickserver_uri)):
+                    validation_level = ValidationLevel.Provider_Trust
+
                 d = self.put_raw_key(
                     server_keys['openpgp'],
                     OpenPGPKey,
                     address=address,
-                    validation=ValidationLevel.Provider_Trust)
+                    validation=validation_level)
         except requests.exceptions.HTTPError as e:
             if e.response.status_code == 404:
                 d = defer.fail(KeyNotFound(address))
@@ -786,6 +795,35 @@ class KeyManager(object):
         if ktype not in self._wrapper_map:
             raise UnsupportedKeyTypeError(str(ktype))
 
+
+def _split_email(address):
+    """
+    Split username and domain from an email address
+
+    :param address: an email address
+    :type address: str
+
+    :return: username and domain from the email address
+    :rtype: (str, str)
+    """
+    if address.count("@") != 1:
+        return None
+    return address.split("@")
+
+
+def _get_domain(url):
+    """
+    Get the domain from an url
+
+    :param url: an url
+    :type url: str
+
+    :return: the domain part of the url
+    :rtype: str
+    """
+    return urlparse(url).hostname
+
+
 from ._version import get_versions
 __version__ = get_versions()['version']
 del get_versions