Implement Http/2 WebSockets (dotnet#41558)

Author: Tratcher

src/Hosting/TestHost/src/RequestFeature.cs

@@ -0,0 +1,30 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+
+using System.Diagnostics.CodeAnalysis;
+
+namespace Microsoft.AspNetCore.Http.Features;
+
+/// <summary>
+/// Used with protocols that require the Extended CONNECT handshake such as HTTP/2 WebSockets and WebTransport.
+/// https://www.rfc-editor.org/rfc/rfc8441#section-4
+/// </summary>
+public interface IHttpExtendedConnectFeature
+{
+    /// <summary>
+    /// Indicates if the current request is a Extended CONNECT request that can be transitioned to an opaque connection via AcceptAsync.
+    /// </summary>
+    [MemberNotNullWhen(true, nameof(Protocol))]
+    bool IsExtendedConnect { get; }
+
+    /// <summary>
+    /// The <c>:protocol</c> header included in the request.
+    /// </summary>
+    string? Protocol { get; }
+
+    /// <summary>
+    /// Send the response headers with a 200 status code and transition to opaque streaming.
+    /// </summary>
+    /// <returns>An opaque bidirectional stream.</returns>
+    ValueTask<Stream> AcceptAsync();
+}

src/Http/Http.Features/src/IHttpExtendedConnectFeature.cs

@@ -1 +1,5 @@
 #nullable enable
+Microsoft.AspNetCore.Http.Features.IHttpExtendedConnectFeature
+Microsoft.AspNetCore.Http.Features.IHttpExtendedConnectFeature.AcceptAsync() -> System.Threading.Tasks.ValueTask<System.IO.Stream!>
+Microsoft.AspNetCore.Http.Features.IHttpExtendedConnectFeature.IsExtendedConnect.get -> bool
+Microsoft.AspNetCore.Http.Features.IHttpExtendedConnectFeature.Protocol.get -> string?

src/Http/Http.Features/src/PublicAPI.Unshipped.txt

@@ -11,7 +11,7 @@
     "EchoApp": {
       "commandName": "Project",
       "launchBrowser": true,
-      "launchUrl": "http://localhost:5000",
+      "launchUrl": "https://localhost:5001",
       "environmentVariables": {
         "ASPNETCORE_ENVIRONMENT": "Development"
       }

src/Middleware/WebSockets/samples/EchoApp/Properties/launchSettings.json

@@ -29,7 +29,7 @@ public void Configure(IApplicationBuilder app, IWebHostEnvironment env, ILoggerF
         {
             if (context.WebSockets.IsWebSocketRequest)
             {
-                var webSocket = await context.WebSockets.AcceptWebSocketAsync();
+                var webSocket = await context.WebSockets.AcceptWebSocketAsync(new WebSocketAcceptContext() { DangerousEnableCompression = true });
                 await Echo(context, webSocket, loggerFactory.CreateLogger("Echo"));
             }
             else

src/Middleware/WebSockets/samples/EchoApp/Startup.cs

@@ -17,15 +17,17 @@ internal static class HandshakeHelpers
     // This uses C# compiler's ability to refer to static data directly. For more information see https://vcsjones.dev/2019/02/01/csharp-readonly-span-bytes-static
     private static ReadOnlySpan<byte> EncodedWebSocketKey => "258EAFA5-E914-47DA-95CA-C5AB0DC85B11"u8;
 
-    // Verify Method, Upgrade, Connection, version,  key, etc..
-    public static void GenerateResponseHeaders(string key, string? subProtocol, IHeaderDictionary headers)
+    public static void GenerateResponseHeaders(bool isHttp1, IHeaderDictionary requestHeaders, string? subProtocol, IHeaderDictionary responseHeaders)
     {
-        headers.Connection = HeaderNames.Upgrade;
-        headers.Upgrade = Constants.Headers.UpgradeWebSocket;
-        headers.SecWebSocketAccept = CreateResponseKey(key);
+        if (isHttp1)
+        {
+            responseHeaders.Connection = HeaderNames.Upgrade;
+            responseHeaders.Upgrade = Constants.Headers.UpgradeWebSocket;
+            responseHeaders.SecWebSocketAccept = CreateResponseKey(requestHeaders.SecWebSocketKey.ToString());
+        }
         if (!string.IsNullOrWhiteSpace(subProtocol))
         {
-            headers.SecWebSocketProtocol = subProtocol;
+            responseHeaders.SecWebSocketProtocol = subProtocol;
         }
     }
 

src/Middleware/WebSockets/src/HandshakeHelpers.cs

@@ -62,11 +62,11 @@ public Task Invoke(HttpContext context)
     {
         // Detect if an opaque upgrade is available. If so, add a websocket upgrade.
         var upgradeFeature = context.Features.Get<IHttpUpgradeFeature>();
-        if (upgradeFeature != null && context.Features.Get<IHttpWebSocketFeature>() == null)
+        var connectFeature = context.Features.Get<IHttpExtendedConnectFeature>();
+        if ((upgradeFeature != null || connectFeature != null) && context.Features.Get<IHttpWebSocketFeature>() == null)
         {
-            var webSocketFeature = new UpgradeHandshake(context, upgradeFeature, _options, _logger);
+            var webSocketFeature = new WebSocketHandshake(context, upgradeFeature, connectFeature, _options, _logger);
             context.Features.Set<IHttpWebSocketFeature>(webSocketFeature);
-
             if (!_anyOriginAllowed)
             {
                 // Check for Origin header
@@ -88,18 +88,21 @@ public Task Invoke(HttpContext context)
         return _next(context);
     }
 
-    private sealed class UpgradeHandshake : IHttpWebSocketFeature
+    private sealed class WebSocketHandshake : IHttpWebSocketFeature
     {
         private readonly HttpContext _context;
-        private readonly IHttpUpgradeFeature _upgradeFeature;
+        private readonly IHttpUpgradeFeature? _upgradeFeature;
+        private readonly IHttpExtendedConnectFeature? _connectFeature;
         private readonly WebSocketOptions _options;
         private readonly ILogger _logger;
         private bool? _isWebSocketRequest;
+        private bool _isH2WebSocket;
 
-        public UpgradeHandshake(HttpContext context, IHttpUpgradeFeature upgradeFeature, WebSocketOptions options, ILogger logger)
+        public WebSocketHandshake(HttpContext context, IHttpUpgradeFeature? upgradeFeature, IHttpExtendedConnectFeature? connectFeature, WebSocketOptions options, ILogger logger)
         {
             _context = context;
             _upgradeFeature = upgradeFeature;
+            _connectFeature = connectFeature;
             _options = options;
             _logger = logger;
         }
@@ -110,14 +113,19 @@ public bool IsWebSocketRequest
             {
                 if (_isWebSocketRequest == null)
                 {
-                    if (!_upgradeFeature.IsUpgradableRequest)
+                    if (_connectFeature?.IsExtendedConnect == true)
                     {
-                        _isWebSocketRequest = false;
+                        _isH2WebSocket = CheckSupportedWebSocketRequestH2(_context.Request.Method, _connectFeature.Protocol, _context.Request.Headers);
+                        _isWebSocketRequest = _isH2WebSocket;
                     }
-                    else
+                    else if (_upgradeFeature?.IsUpgradableRequest == true)
                     {
                         _isWebSocketRequest = CheckSupportedWebSocketRequest(_context.Request.Method, _context.Request.Headers);
                     }
+                    else
+                    {
+                        _isWebSocketRequest = false;
+                    }
                 }
                 return _isWebSocketRequest.Value;
             }
@@ -127,7 +135,7 @@ public async Task<WebSocket> AcceptAsync(WebSocketAcceptContext acceptContext)
         {
             if (!IsWebSocketRequest)
             {
-                throw new InvalidOperationException("Not a WebSocket request."); // TODO: LOC
+                throw new InvalidOperationException("Not a WebSocket request.");
             }
 
             string? subProtocol = null;
@@ -154,8 +162,7 @@ public async Task<WebSocket> AcceptAsync(WebSocketAcceptContext acceptContext)
                 }
             }
 
-            var key = _context.Request.Headers.SecWebSocketKey.ToString();
-            HandshakeHelpers.GenerateResponseHeaders(key, subProtocol, _context.Response.Headers);
+            HandshakeHelpers.GenerateResponseHeaders(!_isH2WebSocket, _context.Request.Headers, subProtocol, _context.Response.Headers);
 
             WebSocketDeflateOptions? deflateOptions = null;
             if (enableCompression)
@@ -187,7 +194,18 @@ public async Task<WebSocket> AcceptAsync(WebSocketAcceptContext acceptContext)
                 }
             }
 
-            Stream opaqueTransport = await _upgradeFeature.UpgradeAsync(); // Sets status code to 101
+            Stream opaqueTransport;
+            // HTTP/2
+            if (_isH2WebSocket)
+            {
+                // Send the response headers
+                opaqueTransport = await _connectFeature!.AcceptAsync();
+            }
+            // HTTP/1.1
+            else
+            {
+                opaqueTransport = await _upgradeFeature!.UpgradeAsync(); // Sets status code to 101
+            }
 
             return WebSocket.CreateFromStream(opaqueTransport, new WebSocketCreationOptions()
             {
@@ -205,17 +223,22 @@ public static bool CheckSupportedWebSocketRequest(string method, IHeaderDictiona
                 return false;
             }
 
+            if (!CheckWebSocketVersion(requestHeaders))
+            {
+                return false;
+            }
+
             var foundHeader = false;
 
-            var values = requestHeaders.GetCommaSeparatedValues(HeaderNames.SecWebSocketVersion);
+            var values = requestHeaders.GetCommaSeparatedValues(HeaderNames.Upgrade);
             foreach (var value in values)
             {
-                if (string.Equals(value, Constants.Headers.SupportedVersion, StringComparison.OrdinalIgnoreCase))
+                if (string.Equals(value, Constants.Headers.UpgradeWebSocket, StringComparison.OrdinalIgnoreCase))
                 {
                     // WebSockets are long lived; so if the header values are valid we switch them out for the interned versions.
                     if (values.Length == 1)
                     {
-                        requestHeaders.SecWebSocketVersion = Constants.Headers.SupportedVersion;
+                        requestHeaders.Upgrade = Constants.Headers.UpgradeWebSocket;
                     }
                     foundHeader = true;
                     break;
@@ -245,28 +268,43 @@ public static bool CheckSupportedWebSocketRequest(string method, IHeaderDictiona
             {
                 return false;
             }
-            foundHeader = false;
 
-            values = requestHeaders.GetCommaSeparatedValues(HeaderNames.Upgrade);
+            return HandshakeHelpers.IsRequestKeyValid(requestHeaders.SecWebSocketKey.ToString());
+        }
+
+        // https://datatracker.ietf.org/doc/html/rfc8441
+        // :method = CONNECT
+        // :protocol = websocket
+        // :scheme = https
+        // :path = /chat
+        // :authority = server.example.com
+        // sec-websocket-protocol = chat, superchat
+        // sec-websocket-extensions = permessage-deflate
+        // sec-websocket-version = 13
+        // origin = http://www.example.com
+        public static bool CheckSupportedWebSocketRequestH2(string method, string? protocol, IHeaderDictionary requestHeaders)
+        {
+            return HttpMethods.IsConnect(method)
+                && string.Equals(protocol, Constants.Headers.UpgradeWebSocket, StringComparison.OrdinalIgnoreCase)
+                && CheckWebSocketVersion(requestHeaders);
+        }
+
+        public static bool CheckWebSocketVersion(IHeaderDictionary requestHeaders)
+        {
+            var values = requestHeaders.GetCommaSeparatedValues(HeaderNames.SecWebSocketVersion);
             foreach (var value in values)
             {
-                if (string.Equals(value, Constants.Headers.UpgradeWebSocket, StringComparison.OrdinalIgnoreCase))
+                if (string.Equals(value, Constants.Headers.SupportedVersion, StringComparison.OrdinalIgnoreCase))
                 {
                     // WebSockets are long lived; so if the header values are valid we switch them out for the interned versions.
                     if (values.Length == 1)
                     {
-                        requestHeaders.Upgrade = Constants.Headers.UpgradeWebSocket;
+                        requestHeaders.SecWebSocketVersion = Constants.Headers.SupportedVersion;
                     }
-                    foundHeader = true;
-                    break;
+                    return true;
                 }
             }
-            if (!foundHeader)
-            {
-                return false;
-            }
-
-            return HandshakeHelpers.IsRequestKeyValid(requestHeaders.SecWebSocketKey.ToString());
+            return false;
         }
     }
 

src/Middleware/WebSockets/src/WebSocketMiddleware.cs

@@ -0,0 +1,74 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+
+using Microsoft.AspNetCore.Builder;
+using Microsoft.AspNetCore.Hosting;
+using Microsoft.AspNetCore.Http;
+using Microsoft.AspNetCore.Http.Features;
+using Microsoft.AspNetCore.TestHost;
+using Microsoft.Extensions.Hosting;
+using Microsoft.Net.Http.Headers;
+
+namespace Microsoft.AspNetCore.WebSockets.Tests;
+
+public class Http2WebSocketTests
+{
+    [Fact]
+    public async Task Http2Handshake_Success()
+    {
+        using var host = new HostBuilder()
+            .ConfigureWebHost(webHost =>
+            {
+                webHost.UseTestServer();
+                webHost.Configure(app =>
+                {
+                    app.UseWebSockets();
+                    app.Run(httpContext =>
+                    {
+                        Assert.True(httpContext.WebSockets.IsWebSocketRequest);
+                        Assert.Equal(new[] { "p1", "p2" }, httpContext.WebSockets.WebSocketRequestedProtocols);
+                        return httpContext.WebSockets.AcceptWebSocketAsync("p2");
+                    });
+                });
+            }).Start();
+
+        var testServer = host.GetTestServer();
+
+        var result = await testServer.SendAsync(httpContext =>
+        {
+            httpContext.Request.Method = HttpMethods.Connect;
+            httpContext.Features.Set<IHttpExtendedConnectFeature>(new ConnectFeature()
+            {
+                IsExtendedConnect = true,
+                Protocol = "WebSocket",
+            });
+            httpContext.Request.Headers.SecWebSocketVersion = Constants.Headers.SupportedVersion;
+            httpContext.Request.Headers.SecWebSocketProtocol = "p1, p2";
+        });
+
+        Assert.Equal(StatusCodes.Status200OK, result.Response.StatusCode);
+        var headers = result.Response.Headers;
+        Assert.Equal("p2", headers.SecWebSocketProtocol);
+        Assert.False(headers.TryGetValue(HeaderNames.Connection, out var _));
+        Assert.False(headers.TryGetValue(HeaderNames.Upgrade, out var _));
+        Assert.False(headers.TryGetValue(HeaderNames.SecWebSocketAccept, out var _));
+    }
+
+    public sealed class ConnectFeature : IHttpExtendedConnectFeature
+    {
+        public bool IsExtendedConnect { get; set; }
+        public string Protocol { get; set; }
+        public Stream Stream { get; set; } = Stream.Null;
+
+        /// <inheritdoc/>
+        public ValueTask<Stream> AcceptAsync()
+        {
+            if (!IsExtendedConnect)
+            {
+                throw new InvalidOperationException("This is not an Extended CONNECT request.");
+            }
+
+            return new ValueTask<Stream>(Stream);
+        }
+    }
+}

src/Middleware/WebSockets/test/UnitTests/Http2WebSocketTests.cs

@@ -8,6 +8,7 @@
     <ProjectReference Include="$(RepoRoot)src\Hosting\Server.IntegrationTesting\src\Microsoft.AspNetCore.Server.IntegrationTesting.csproj" />
 
     <Reference Include="Microsoft.AspNetCore.Server.Kestrel" />
+    <Reference Include="Microsoft.AspNetCore.TestHost" />
     <Reference Include="Microsoft.AspNetCore.WebSockets" />
   </ItemGroup>