Implement InvalidAuthProvider

Implements the InvalidAuthProvider, which acts as a fallback if a
configured authentication provider, e.g. LDAP, is unavailable due
to a load failure or removal. Until the user or the authentication
plugin is corrected, this will cause users with the missing provider
to be locked out, while throwing errors in the logs about the issue.

Fixes #1445 part 2

1 files changed, 15 insertions, 5 deletions

diff --git a/Emby.Server.Implementations/Library/UserManager.cs b/Emby.Server.Implementations/Library/UserManager.cs
index a0b8d4ba4..ca43f7aaa 100644
--- a/Emby.Server.Implementations/Library/UserManager.cs
+++ b/Emby.Server.Implementations/Library/UserManager.cs
@@ -79,6 +79,8 @@ namespace Emby.Server.Implementations.Library
         private IAuthenticationProvider[] _authenticationProviders;
         private DefaultAuthenticationProvider _defaultAuthenticationProvider;
 
+        private InvalidAuthProvider _invalidAuthProvider;
+
         private IPasswordResetProvider[] _passwordResetProviders;
         private DefaultPasswordResetProvider _defaultPasswordResetProvider;
 
@@ -141,6 +143,8 @@ namespace Emby.Server.Implementations.Library
 
             _defaultAuthenticationProvider = _authenticationProviders.OfType<DefaultAuthenticationProvider>().First();
 
+            _invalidAuthProvider = _authenticationProviders.OfType<InvalidAuthProvider>().First();
+
             _passwordResetProviders = passwordResetProviders.ToArray();
 
             _defaultPasswordResetProvider = passwordResetProviders.OfType<DefaultPasswordResetProvider>().First();
@@ -307,11 +311,14 @@ namespace Emby.Server.Implementations.Library
                     user = Users
                         .FirstOrDefault(i => string.Equals(username, i.Name, StringComparison.OrdinalIgnoreCase));
 
-                    var hasNewUserPolicy = authenticationProvider as IHasNewUserPolicy;
-                    if (hasNewUserPolicy != null)
+                    if (authenticationProvider.GetType() != typeof(InvalidAuthProvider))
                     {
-                        var policy = hasNewUserPolicy.GetNewUserPolicy();
-                        UpdateUserPolicy(user, policy, true);
+                        var hasNewUserPolicy = authenticationProvider as IHasNewUserPolicy;
+                        if (hasNewUserPolicy != null)
+                        {
+                            var policy = hasNewUserPolicy.GetNewUserPolicy();
+                            UpdateUserPolicy(user, policy, true);
+                        }
                     }
                 }
             }
@@ -400,7 +407,10 @@ namespace Emby.Server.Implementations.Library
 
             if (providers.Length == 0)
             {
-                providers = new IAuthenticationProvider[] { _defaultAuthenticationProvider };
+                // this function used to assign any user without an auth provider to the default.
+                // we're going to have it use a new function now.
+                _logger.LogWarning($"The user {user.Name} was found but no Authentication Provider with ID: {user.Policy.AuthenticationProviderId} was found. Assigning user to InvalidAuthProvider temporarily");
+                providers = new IAuthenticationProvider[] { _invalidAuthProvider };
             }
 
             return providers;