When constructing KeyringBackend subclasses, wrap set_password to enf…

…orce non-empty usernames.

keyring/backend.py

@@ -6,6 +6,7 @@
 
 import abc
 import copy
+import functools
 import logging
 import operator
 import os
@@ -30,11 +31,14 @@ class KeyringBackendMeta(abc.ABCMeta):
     Specialized subclass behavior.
 
     Keeps a registry of all (non-abstract) types.
+
+    Wraps set_password to validate the username.
     """
 
     def __init__(cls, name, bases, dict):
         super().__init__(name, bases, dict)
         cls._register()
+        cls._validate_username_in_set_password()
 
     def _register(cls):
         if not hasattr(cls, '_classes'):
@@ -43,6 +47,19 @@ def _register(cls):
         if not cls.__abstractmethods__:
             classes.add(cls)
 
+    def _validate_username_in_set_password(cls):
+        """
+        Wrap ``set_password`` such to validate the passed username.
+        """
+        orig = cls.set_password
+
+        @functools.wraps(orig)
+        def wrapper(self, system, username, *args, **kwargs):
+            self._validate_username(username)
+            return orig(self, system, username, *args, **kwargs)
+
+        cls.set_password = wrapper
+
 
 class KeyringBackend(metaclass=KeyringBackendMeta):
     """The abstract base class of the keyring, every backend must implement
@@ -121,8 +138,6 @@ def _validate_username(self, username: str) -> None:
     def set_password(self, service: str, username: str, password: str) -> None:
         """Set password for the username of the service.
 
-        Implementations should call ``._validate_username``.
-
         If the backend cannot store passwords, raise
         PasswordSetError.
         """

keyring/backends/SecretService.py

@@ -84,7 +84,6 @@ def get_password(self, service, username):
 
     def set_password(self, service, username, password):
         """Set password for the username of the service"""
-        self._validate_username(username)
         collection = self.get_preferred_collection()
         attributes = self._query(service, username, application=self.appid)
         label = f"Password for '{username}' on '{service}'"

keyring/backends/Windows.py

@@ -113,7 +113,6 @@ def _get_password(self, target):
         return DecodingCredential(res)
 
     def set_password(self, service, username, password):
-        self._validate_username(username)
         existing_pw = self._get_password(service)
         if existing_pw:
             # resave the existing password using a compound target

keyring/backends/kwallet.py

@@ -139,7 +139,6 @@ def set_password(self, service, username, password):
         if not self.connected(service):
             # the user pressed "cancel" when prompted to unlock their keyring.
             raise PasswordSetError("Cancelled by user")
-        self._validate_username(username)
         self.iface.writePassword(self.handle, service, username, password, self.appid)
 
     def delete_password(self, service, username):

keyring/backends/libsecret.py

@@ -82,7 +82,6 @@ def get_password(self, service, username):
 
     def set_password(self, service, username, password):
         """Set password for the username of the service"""
-        self._validate_username(username)
         attributes = self._query(service, username, application=self.appid)
         label = f"Password for '{username}' on '{service}'"
         try:

keyring/backends/macOS/__init__.py

@@ -42,7 +42,6 @@ def priority(cls):
 
     @warn_keychain
     def set_password(self, service, username, password):
-        self._validate_username(username)
         if username is None:
             username = ''
 

keyring/backends/null.py

@@ -17,7 +17,4 @@ def priority(cls) -> float:
     def get_password(self, service, username, password=None):
         pass
 
-    delete_password = get_password  # type: ignore
-
-    def set_password(self, service, username, password):
-        self._validate_username(username)
+    set_password = delete_password = get_password  # type: ignore