SECURITY FIX FOR LDAP

It appears the recent migration of the LDAP code and add of a check for the admin username/password being invalid *broke the LDAP password check*, allowing any password to succeed for login. This fixes the problem, add unit tests to verify the fix and add some tests to our other external auth test suite.

A release will be needed immediately along with an announcement

data/users/externalldap.py

@@ -9,6 +9,16 @@ from data.users.federated import FederatedUsers, VerifiedCredentials
 logger = logging.getLogger(__name__)
 
 
+class LDAPConnectionBuilder(object):
+  def __init__(self, ldap_uri, user_dn, user_pw):
+    self._ldap_uri = ldap_uri
+    self._user_dn = user_dn
+    self._user_pw = user_pw
+
+  def get_connection(self):
+    return LDAPConnection(self._ldap_uri, self._user_dn, self._user_pw)
+
+
 class LDAPConnection(object):
   def __init__(self, ldap_uri, user_dn, user_pw):
     self._ldap_uri = ldap_uri
@@ -20,13 +30,7 @@ class LDAPConnection(object):
     trace_level = 2 if os.environ.get('USERS_DEBUG') == '1' else 0
     self._conn = ldap.initialize(self._ldap_uri, trace_level=trace_level)
     self._conn.set_option(ldap.OPT_REFERRALS, 1)
-
-    try:
-      self._conn.simple_bind_s(self._user_dn, self._user_pw)
-    except ldap.INVALID_CREDENTIALS:
-      logger.exception('LDAP admin dn or password are invalid')
-      return None
-
+    self._conn.simple_bind_s(self._user_dn, self._user_pw)
     return self._conn
 
   def __exit__(self, exc_type, value, tb):
@@ -38,7 +42,7 @@ class LDAPUsers(FederatedUsers):
 
   def __init__(self, ldap_uri, base_dn, admin_dn, admin_passwd, user_rdn, uid_attr, email_attr):
     super(LDAPUsers, self).__init__('ldap')
-    self._ldap_conn = LDAPConnection(ldap_uri, admin_dn, admin_passwd)
+    self._ldap = LDAPConnectionBuilder(ldap_uri, admin_dn, admin_passwd)
     self._ldap_uri = ldap_uri
     self._base_dn = base_dn
     self._user_rdn = user_rdn
@@ -65,10 +69,15 @@ class LDAPUsers(FederatedUsers):
     return referral_dn
 
   def _ldap_user_search(self, username_or_email):
-    with self._ldap_conn as conn:
-      if conn is None:
-        return (None, 'LDAP Admin dn or password is invalid')
+    # Verify the admin connection works first. We do this here to avoid wrapping
+    # the entire block in the INVALID CREDENTIALS check.
+    try:
+      with self._ldap.get_connection():
+        pass
+    except ldap.INVALID_CREDENTIALS:
+      return (None, 'LDAP Admin dn or password is invalid')
 
+    with self._ldap.get_connection() as conn:
       logger.debug('Incoming username or email param: %s', username_or_email.__repr__())
       user_search_dn = ','.join(self._user_rdn + self._base_dn)
       query = u'(|({0}={2})({1}={2}))'.format(self._uid_attr, self._email_attr,

test/test_external_jwt_authn.py

@@ -114,6 +114,9 @@ class JWTAuthTestCase(LiveServerTestCase):
     self.assertIsNotNone(result)
 
     # Confirm a user with the same internal and external username.
+    result, _ = self.jwt_auth.confirm_existing_user('cooluser', 'invalidpassword')
+    self.assertIsNone(result)
+
     result, _ = self.jwt_auth.confirm_existing_user('cooluser', 'password')
     self.assertIsNotNone(result)
     self.assertEquals('cooluser', result.username)

test/test_ldap.py

@@ -112,6 +112,17 @@ class TestLDAP(unittest.TestCase):
     (response, _) = self.ldap.confirm_existing_user('someuser', 'somepass')
     self.assertEquals(response.username, 'someuser')
 
+  def test_invalid_password(self):
+    # Verify we cannot login with an invalid password.
+    (response, err_msg) = self.ldap.verify_and_link_user('someuser', 'invalidpass')
+    self.assertIsNone(response)
+    self.assertEquals(err_msg, 'Invalid password')
+
+    # Verify we cannot confirm the user.
+    (response, err_msg) = self.ldap.confirm_existing_user('someuser', 'invalidpass')
+    self.assertIsNone(response)
+    self.assertEquals(err_msg, 'Invalid user')
+
   def test_missing_mail(self):
     (response, err_msg) = self.ldap.verify_and_link_user('nomail', 'somepass')
     self.assertIsNone(response)