Add support for a scheme property in SecretService backend. Set to 'K…

…eypassXC' to use the username/system convention from KeypassXC, either with KEYRING_PROPERTY_SCHEME or keyring.with_properties(scheme='KeypassXC'). Fixes #448.

keyring/backend.py

@@ -6,6 +6,7 @@
 import abc
 import logging
 import operator
+import copy
 
 from typing import Optional
 
@@ -151,6 +152,11 @@ def parse(item):
         for name, value in props:
             setattr(self, name, value)
 
+    def with_properties(self, **kwargs):
+        alt = copy.copy(self)
+        vars(alt).update(kwargs)
+        return alt
+
 
 class Crypter:
     """Base class providing encryption and decryption"""

keyring/backends/SecretService.py

@@ -27,6 +27,12 @@ class Keyring(KeyringBackend):
     """Secret Service Keyring"""
 
     appid = 'Python keyring library'
+    scheme = 'default'
+
+    schemes = dict(
+        default=dict(username='username', service='service'),
+        KeypassXC=dict(username='UserName', service='Title'),
+    )
 
     @properties.ClassProperty
     @classmethod
@@ -73,23 +79,35 @@ def unlock(self, item):
         if item.is_locked():  # User dismissed the prompt
             raise KeyringLocked('Failed to unlock the item!')
 
+    def _query(self, service, username):
+        scheme = self.schemes[self.scheme]
+        return (
+            {
+                scheme['username']: username,
+                scheme['service']: service,
+            }
+            if username
+            else {
+                scheme['service']: service,
+            }
+        )
+
     def get_password(self, service, username):
         """Get password of the username for the service"""
         collection = self.get_preferred_collection()
         with closing(collection.connection):
-            items = collection.search_items({"username": username, "service": service})
+            items = collection.search_items(self._query(service, username))
             for item in items:
                 self.unlock(item)
                 return item.get_secret().decode('utf-8')
 
     def set_password(self, service, username, password):
         """Set password for the username of the service"""
         collection = self.get_preferred_collection()
-        attributes = {
-            "application": self.appid,
-            "service": service,
-            "username": username,
-        }
+        attributes = dict(
+            self._query(service, username),
+            application=self.appid,
+        )
         label = "Password for '{}' on '{}'".format(username, service)
         with closing(collection.connection):
             collection.create_item(label, attributes, password, replace=True)
@@ -98,7 +116,7 @@ def delete_password(self, service, username):
         """Delete the stored password (only the first one)"""
         collection = self.get_preferred_collection()
         with closing(collection.connection):
-            items = collection.search_items({"username": username, "service": service})
+            items = collection.search_items(self._query(service, username))
             for item in items:
                 return item.delete()
         raise PasswordDeleteError("No such password!")
@@ -111,16 +129,13 @@ def get_credential(self, service, username):
         and return a SimpleCredential containing  the username and password
         Otherwise, it will return the first username and password combo that it finds.
         """
-
-        query = {"service": service}
-        if username:
-            query["username"] = username
-
+        scheme = self.schemes[self.scheme]
+        query = self._query(service, username)
         collection = self.get_preferred_collection()
 
         with closing(collection.connection):
             items = collection.search_items(query)
             for item in items:
                 self.unlock(item)
-                username = item.get_attributes().get("username")
+                username = item.get_attributes().get(scheme['username'])
                 return SimpleCredential(username, item.get_secret().decode('utf-8'))