Allow users to configure group search filter and attributes

Author: kinow

README.md

@@ -127,6 +127,35 @@ c.LDAPAuthenticator.allowed_groups = [
 ]
 ```
 
+#### `LDAPAuthenticator.group_search_filter`
+
+The LDAP group search filter.
+
+The default value is an LDAP OR search that looks like the following:
+
+```
+(|(member={userdn})(uniqueMember={userdn})(memberUid={uid}))
+```
+
+So it basically compares the `userdn` attribute against the `member` attribute,
+then against the `uniqueMember`, and finally checks the `memberUid` against
+the `uid`.
+
+If you modify this value, you probably want to change `group_attributes` too.
+Here is an example that should work with OpenLDAP servers.
+
+```
+(member={userdn})
+```
+
+#### `LDAPAuthenticator.group_attributes`
+
+A list of attributes used when searching for LDAP groups.
+
+By default, it uses `member`, `uniqueMember`, and `memberUid`. Certain
+servers may reject invalid values causing exceptions during
+authentication.
+
 #### `LDAPAuthenticator.valid_username_regex`
 
 All usernames will be checked against this before being sent

ldapauthenticator/ldapauthenticator.py

@@ -94,6 +94,23 @@ def _validate_bind_dn_template(self, proposal):
         """,
     )
 
+    group_search_filter = Unicode(
+        config=True,
+        default_value="(|(member={userdn})(uniqueMember={userdn})(memberUid={uid}))",
+        help="""
+        The search filter used to locate groups.
+
+        Certain server types may use different values, and may also
+        reject invalid values by raising exceptions.
+        """,
+    )
+
+    group_attributes = List(
+        config=True,
+        default_value=["member", "uniqueMember", "memberUid"],
+        help="List of attributes to be searched",
+    )
+
     # FIXME: Use something other than this? THIS IS LAME, akin to websites restricting things you
     # can use in usernames / passwords to protect from SQL injection!
     valid_username_regex = Unicode(
@@ -412,25 +429,24 @@ async def authenticate(self, handler, data):
                 return None
 
         if self.allowed_groups:
+            if not self.group_search_filter or not self.group_attributes:
+                self.log.warning(
+                    "Missing group_search_filter or group_attributes. Both are required."
+                )
+                return None
             self.log.debug("username:%s Using dn %s", username, userdn)
             found = False
             for group in self.allowed_groups:
-                group_filter = (
-                    "(|"
-                    "(member={userdn})"
-                    "(uniqueMember={userdn})"
-                    "(memberUid={uid})"
-                    ")"
-                )
-                group_filter = group_filter.format(
+                group_search_filter = self.group_search_filter
+                group_filter = group_search_filter.format(
                     userdn=escape_filter_chars(userdn),
                     uid=escape_filter_chars(username),
                 )
-                group_attributes = ["member", "uniqueMember", "memberUid"]
+                group_attributes = self.group_attributes
                 found = conn.search(
                     group,
                     search_scope=ldap3.BASE,
-                    search_filter=group_filter,
+                    search_filter=group_search_filter,
                     attributes=group_attributes,
                 )
                 if found:

ldapauthenticator/tests/conftest.py

@@ -17,6 +17,10 @@ def authenticator():
     authenticator.escape_userdn = True
     authenticator.attributes = ["uid", "cn", "mail", "ou"]
     authenticator.use_lookup_dn_username = False
+    authenticator.group_filter = (
+        "(|(member={userdn})(uniqueMember={userdn})(memberUid={uid}))"
+    )
+    authenticator.group_attributes = ["member", "uniqueMember", "memberUid"]
 
     authenticator.allowed_groups = [
         "cn=admin_staff,ou=people,dc=planetexpress,dc=com",

ldapauthenticator/tests/test_ldapauthenticator.py

@@ -104,3 +104,15 @@ async def test_ldap_auth_state_attributes(authenticator):
     )
     assert authorized["name"] == "fry"
     assert authorized["auth_state"] == {"employeeType": ["Delivery boy"]}
+
+
+async def test_ldap_auth_state_attributes2(authenticator):
+    authenticator.group_search_filter = "(cn=ship_crew)"
+    authenticator.group_attributes = ["cn"]
+    authenticator.auth_state_attributes = ["description"]
+    # proper username and password in allowed group
+    authorized = await authenticator.get_authenticated_user(
+        None, {"username": "leela", "password": "leela"}
+    )
+    assert authorized["name"] == "leela"
+    assert authorized["auth_state"] == {"description": ["Mutant"]}