Automatically abort interactive challenge demands when no client identifier could be resolved

src/OpenIddict.Abstractions/OpenIddictResources.resx

@@ -1564,6 +1564,9 @@ To apply post-logout redirection responses, create a class implementing 'IOpenId
   <data name="ID0417" xml:space="preserve">
     <value>The authentication properties must not contain an '.issuer', '.provider_name' or '.registration_id' property when using a forwarded authentication scheme/type.</value>
   </data>
+  <data name="ID0418" xml:space="preserve">
+    <value>A client identifier must be specified in the client registration or web provider options when using 'response_type=none', the authorization code/hybrid/implicit flows or the device authorization flow.</value>
+  </data>
   <data name="ID2000" xml:space="preserve">
     <value>The security token is missing.</value>
   </data>

src/OpenIddict.Client/OpenIddictClientHandlers.cs

@@ -4640,7 +4640,21 @@ public static partial class OpenIddictClientHandlers
                 throw new ArgumentNullException(nameof(context));
             }
 
-            context.ClientId ??= context.Registration.ClientId;
+            context.ClientId ??= context.Registration.ClientId switch
+            {
+                { Length: > 0 } value => value,
+
+                // Note: the client identifier is required for the authorization code/hybrid/implicit and device flows.
+                // If no client identifier was attached to the registration, abort the challenge demand immediately.
+                _ when context.GrantType is GrantTypes.AuthorizationCode or GrantTypes.DeviceCode or GrantTypes.Implicit
+                    => throw new InvalidOperationException(SR.GetResourceString(SR.ID0418)),
+
+                // Note: the client identifier is also required for the special response_type=none flow.
+                _ when context.GrantType is null && context.ResponseType is ResponseTypes.None
+                    => throw new InvalidOperationException(SR.GetResourceString(SR.ID0418)),
+
+                _ => null
+            };
 
             return default;
         }