HttpListenerContext.AcceptWebSocketAsync unsupported for IWindowsPrincipal in .NET Core 3.1

[iconics-janb]

Description

HttpListenerContext.AcceptWebSocketAsync throws PlatformNotSupportedException when called with User set to WindowsPrincipal. This happens in .NET Core 3.1 when running on Windows. Works fine when running in .NET Framework.

Reproduction Steps

using System;
using System.Diagnostics;
using System.Net;
using System.Net.WebSockets;
using System.Threading;
using System.Threading.Tasks;

namespace WebSocketCloseTest
{
    public class Program
    {
        public static async Task Main(string[] args)
        {
            var serverTask = Server(http://localhost:45000/test/ws/);
            await Client("ws://localhost:45000/test/ws/");
            await serverTask;
        }

        private static async Task Server(String serverAddress)
        {
            var listener = new HttpListener();
            listener.Prefixes.Add(serverAddress);
            listener.AuthenticationSchemes = AuthenticationSchemes.IntegratedWindowsAuthentication;
            listener.Start();

            HttpListenerContext ctx = await listener.GetContextAsync();
            try
            {
                Debug.Assert(ctx.User != null); // this is supposed to be a WindowsPrincipal
                HttpListenerWebSocketContext wsCtx = await ctx.AcceptWebSocketAsync("subProtocol"); // this throws on .NET Core
                await wsCtx.WebSocket.CloseAsync(WebSocketCloseStatus.NormalClosure, null, CancellationToken.None);
            }
            finally
            {
                ctx.Response.Close();
            }
        }

        private static async Task Client(String serverAddress)
        {
            try
            {
                using (ClientWebSocket webSocket = new ClientWebSocket())
                {
                    webSocket.Options.AddSubProtocol("subProtocol");
                    webSocket.Options.Credentials = CredentialCache.DefaultCredentials;
                    await webSocket.ConnectAsync(new Uri(serverAddress), CancellationToken.None);
                    await webSocket.CloseAsync(WebSocketCloseStatus.NormalClosure, null, CancellationToken.None);
                }
            }
            catch (Exception e)
            {
                Console.WriteLine($"Client WS exception: {e.Message}");
            }
        }
    }
}

Expected behavior

It should not throw the exception and work the same way as it does in .NET Framework

Actual behavior

Throws PlatformNotSupportedException.

Regression?

Yes, works in .NET Framework

Known Workarounds

Use reflection to set the _user field to null, make the call and set it back to the original value, like this:

HttpListenerContext ctx = await listener.GetContextAsync();

IPrincipal originalPrincipal = ctx.User;
FieldInfo field = ctx.GetType().GetField("_user", BindingFlags.NonPublic | BindingFlags.Instance);
field.SetValue(_ctx, null);

// make the call with User = null to prevent the exception
wsCtx = await ctx.AcceptWebSocketAsync(WsConstants.SubProtocol, TimeSpan.FromSeconds(WsConstants.KeepAliveIntervalSeconds));

// revert to the original value
field.SetValue(_ctx, originalPrincipal);

Configuration

.NET Core 3.1, Windows 10 x64

Other information

No response

[ghost]

Tagging subscribers to this area: @dotnet/ncl
See info in area-owners.md if you want to be subscribed.

Issue Details

---

Description

HttpListenerContext.AcceptWebSocketAsync throws PlatformNotSupportedException when called with User set to IWindowsPrincipal. This happens in .NET Core 3.1 when running on Windows. Works fine when running in .NET Framework.

Reproduction Steps

HttpListenerContext ctx = await listener.GetContextAsync();
wsCtx = await ctx.AcceptWebSocketAsync(WsConstants.SubProtocol, TimeSpan.FromSeconds(WsConstants.KeepAliveIntervalSeconds));

Expected behavior

It should not throw the exception and work the same way as it does in .NET Framework

Actual behavior

Throws PlatformNotSupportedException.

Regression?

Yes, works in .NET Framework

Known Workarounds

Use reflection to set the _user field to null, make the call and set it back to the original value, like this:

HttpListenerContext ctx = await listener.GetContextAsync();

IPrincipal originalPrincipal = ctx.User;
FieldInfo field = ctx.GetType().GetField("_user", BindingFlags.NonPublic | BindingFlags.Instance);
field.SetValue(_ctx, null);

// make the call with User = null to prevent the exception
wsCtx = await ctx.AcceptWebSocketAsync(WsConstants.SubProtocol, TimeSpan.FromSeconds(WsConstants.KeepAliveIntervalSeconds));

// revert to the original value
field.SetValue(_ctx, originalPrincipal);

Configuration

.NET Core 3.1, Windows 10 x64

Other information

No response

Author:	iconics-janb
Assignees:	-
Labels:	area-System.Net, untriaged
Milestone:	-

[karelz]

Can you give us simple self-contained repro we can run? (I assume the above code snippet is not sufficient)
Can you please test it also on .NET 6?

[iconics-janb]

I will try to provide a repro, but it will take more time. What we found so far was that the exception is actually thrown from HttpListenerWebSocketContext.CopyPrincipal, please see line 104 here: runtime/HttpListenerWebSocketContext.cs at main · dotnet/runtime (github.com)<https://github.com/dotnet/runtime/blob/main/src/libraries/System.Net.HttpListener/src/System/Net/WebSockets/HttpListenerWebSocketContext.cs> I don’t understand why WindowsPrincipal is not supported on Windows… Yes, the same issue exists in .NET 6. -- Can you give us simple self-contained repro we can run? (I assume the above code snippet is not sufficient) Can you please test it also on .NET 6? — Reply to this email directly, view it on GitHub<#63738 (comment)>, or unsubscribe<https://github.com/notifications/unsubscribe-auth/AENLQ3NA47QTMFSMAWUUL6TUV4ASLANCNFSM5L33DOBQ>. Triage notifications on the go with GitHub Mobile for iOS<https://apps.apple.com/app/apple-store/id1477376905?ct=notification-email&mt=8&pt=524675> or Android<https://play.google.com/store/apps/details?id=com.github.android&referrer=utm_campaign%3Dnotification-email%26utm_medium%3Demail%26utm_source%3Dgithub>. You are receiving this because you authored the thread.Message ID: ***@***.******@***.***>>

[iconics-janb]

Here is the repro: using System; using System.Diagnostics; using System.Net; using System.Net.WebSockets; using System.Threading; using System.Threading.Tasks; namespace WebSocketCloseTest { public class Program { public static async Task Main(string[] args) { var serverTask = Server(http://localhost:45000/test/ws/); await Client("ws://localhost:45000/test/ws/"); await serverTask; } private static async Task Server(String serverAddress) { var listener = new HttpListener(); listener.Prefixes.Add(serverAddress); listener.AuthenticationSchemes = AuthenticationSchemes.IntegratedWindowsAuthentication; listener.Start(); HttpListenerContext ctx = await listener.GetContextAsync(); try { Debug.Assert(ctx.User != null); // this is supposed to be a WindowsPrincipal HttpListenerWebSocketContext wsCtx = await ctx.AcceptWebSocketAsync("subProtocol"); // this throws on .NET Core await wsCtx.WebSocket.CloseAsync(WebSocketCloseStatus.NormalClosure, null, CancellationToken.None); } finally { ctx.Response.Close(); } } private static async Task Client(String serverAddress) { try { using (ClientWebSocket webSocket = new ClientWebSocket()) { webSocket.Options.AddSubProtocol("subProtocol"); webSocket.Options.Credentials = CredentialCache.DefaultCredentials; await webSocket.ConnectAsync(new Uri(serverAddress), CancellationToken.None); await webSocket.CloseAsync(WebSocketCloseStatus.NormalClosure, null, CancellationToken.None); } } catch (Exception e) { Console.WriteLine($"Client WS exception: {e.Message}"); } } } }

…

-- Jan Burian, Senior Software Architect t: +420 377 183 420 • iconics.com<https://iconics.com/> ICONICS – A Group Company of Mitsubishi Electric Register HERE<https://iconics.com/connect2021> for ICONICS Connect 2021! ***@***.***<https://iconics.com/newsletter> [A picture containing drawingDescription automatically generated] <https://www.linkedin.com/company/iconics> [A picture containing animal, birdDescription automatically generated] <https://www.twitter.com/ICONICS> [A picture containing kit, drawingDescription automatically generated] <https://www.facebook.com/ICONICSInc> [A picture containing drawingDescription automatically generated] <https://www.youtube.com/user/IconicsVideo> From: Jan Burian Sent: Friday, January 14, 2022 9:30 AM To: dotnet/runtime ***@***.***>; dotnet/runtime ***@***.***> Cc: Czech_Engr_Jan Burian ***@***.***>; Author ***@***.***> Subject: RE: [dotnet/runtime] HttpListenerContext.AcceptWebSocketAsync unsupported for IWindowsPrincipal in .NET Core 3.1 (Issue #63738) I will try to provide a repro, but it will take more time. What we found so far was that the exception is actually thrown from HttpListenerWebSocketContext.CopyPrincipal, please see line 104 here: runtime/HttpListenerWebSocketContext.cs at main · dotnet/runtime (github.com)<https://github.com/dotnet/runtime/blob/main/src/libraries/System.Net.HttpListener/src/System/Net/WebSockets/HttpListenerWebSocketContext.cs> I don’t understand why WindowsPrincipal is not supported on Windows… -- Jan Burian, Senior Software Architect t: +420 377 183 420 • iconics.com<https://iconics.com/> ICONICS – A Group Company of Mitsubishi Electric Register HERE<https://iconics.com/connect2021> for ICONICS Connect 2021! ***@***.***<https://iconics.com/newsletter> [A picture containing drawingDescription automatically generated] <https://www.linkedin.com/company/iconics> [A picture containing animal, birdDescription automatically generated] <https://www.twitter.com/ICONICS> [A picture containing kit, drawingDescription automatically generated] <https://www.facebook.com/ICONICSInc> [A picture containing drawingDescription automatically generated] <https://www.youtube.com/user/IconicsVideo> From: Karel Zikmund ***@***.******@***.***>> Sent: Thursday, January 13, 2022 6:02 PM To: dotnet/runtime ***@***.******@***.***>> Cc: Czech_Engr_Jan Burian ***@***.******@***.***>>; Author ***@***.******@***.***>> Subject: Re: [dotnet/runtime] HttpListenerContext.AcceptWebSocketAsync unsupported for IWindowsPrincipal in .NET Core 3.1 (Issue #63738) Can you give us simple self-contained repro we can run? (I assume the above code snippet is not sufficient) Can you please test it also on .NET 6? — Reply to this email directly, view it on GitHub<#63738 (comment)>, or unsubscribe<https://github.com/notifications/unsubscribe-auth/AENLQ3NA47QTMFSMAWUUL6TUV4ASLANCNFSM5L33DOBQ>. Triage notifications on the go with GitHub Mobile for iOS<https://apps.apple.com/app/apple-store/id1477376905?ct=notification-email&mt=8&pt=524675> or Android<https://play.google.com/store/apps/details?id=com.github.android&referrer=utm_campaign%3Dnotification-email%26utm_medium%3Demail%26utm_source%3Dgithub>. You are receiving this because you authored the thread.Message ID: ***@***.******@***.***>>

[CarnaViire]

Indeed, as @iconics-janb pointed out, our code will throw PNSE if user is WindowsPrincipal:

runtime/src/libraries/System.Net.HttpListener/src/System/Net/WebSockets/HttpListenerWebSocketContext.cs

Line 104 in 57bfe47

throw new PlatformNotSupportedException();

but .NET Framework code contained an implementation for the same condition
https://referencesource.microsoft.com/#System/net/System/Net/WebSockets/HttpListenerWebSocketContext.cs,150

@wfurt @stephentoub Do you know anything that would prevent us from reusing the original code with WindowsPrincipal existing in .NET Framework? I wonder why it was not used in the first place, and why PNSE was used (The PR that introduced it (dotnet/corefx#20398 (comment)) doesn't help). I would expect that user couldn't be WindowsPrincipal on non-Windows platform in the first place - am I missing something?

[wfurt]

Yes, I think we can make it work for Windows (assuming all the dependencies are in place) and PNSE for other platforms.
The original exception was "not implemented" so int feels just something that got dropped from the initial implementation. (and perhaps lost)

[karelz]

Triage: Needs to be ported from .NET Framework. Fairly straightforward work - see link to referencesource above.
Given that this is 1st report in .NET Core timeframe, moving it to Future. We would take a contribution though.