Websocket handshake perf

src/Middleware/Middleware.sln

@@ -293,6 +293,10 @@ Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "Microsoft.AspNetCore.Server
 EndProject
 Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "Microsoft.AspNetCore.SpaServices.Extensions.Tests", "SpaServices.Extensions\test\Microsoft.AspNetCore.SpaServices.Extensions.Tests.csproj", "{D0CB733B-4CE8-4F6C-BBB9-548EA1A96966}"
 EndProject
+Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "Microsoft.AspNetCore.WebSockets.Microbenchmarks", "perf\Microbenchmarks\Microsoft.AspNetCore.WebSockets.Microbenchmarks.csproj", "{C4D624B3-749E-41D8-A43B-B304BC3885EA}"
+EndProject
+Project("{2150E333-8FDC-42A3-9474-1A3956D46DE8}") = "Perf", "Perf", "{4623F52E-2070-4631-8DEE-7D2F48733FFD}"
+EndProject
 Global
 	GlobalSection(SolutionConfigurationPlatforms) = preSolution
 		Debug|Any CPU = Debug|Any CPU
@@ -1599,6 +1603,18 @@ Global
 		{D0CB733B-4CE8-4F6C-BBB9-548EA1A96966}.Release|x64.Build.0 = Release|Any CPU
 		{D0CB733B-4CE8-4F6C-BBB9-548EA1A96966}.Release|x86.ActiveCfg = Release|Any CPU
 		{D0CB733B-4CE8-4F6C-BBB9-548EA1A96966}.Release|x86.Build.0 = Release|Any CPU
+		{C4D624B3-749E-41D8-A43B-B304BC3885EA}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
+		{C4D624B3-749E-41D8-A43B-B304BC3885EA}.Debug|Any CPU.Build.0 = Debug|Any CPU
+		{C4D624B3-749E-41D8-A43B-B304BC3885EA}.Debug|x64.ActiveCfg = Debug|Any CPU
+		{C4D624B3-749E-41D8-A43B-B304BC3885EA}.Debug|x64.Build.0 = Debug|Any CPU
+		{C4D624B3-749E-41D8-A43B-B304BC3885EA}.Debug|x86.ActiveCfg = Debug|Any CPU
+		{C4D624B3-749E-41D8-A43B-B304BC3885EA}.Debug|x86.Build.0 = Debug|Any CPU
+		{C4D624B3-749E-41D8-A43B-B304BC3885EA}.Release|Any CPU.ActiveCfg = Release|Any CPU
+		{C4D624B3-749E-41D8-A43B-B304BC3885EA}.Release|Any CPU.Build.0 = Release|Any CPU
+		{C4D624B3-749E-41D8-A43B-B304BC3885EA}.Release|x64.ActiveCfg = Release|Any CPU
+		{C4D624B3-749E-41D8-A43B-B304BC3885EA}.Release|x64.Build.0 = Release|Any CPU
+		{C4D624B3-749E-41D8-A43B-B304BC3885EA}.Release|x86.ActiveCfg = Release|Any CPU
+		{C4D624B3-749E-41D8-A43B-B304BC3885EA}.Release|x86.Build.0 = Release|Any CPU
 	EndGlobalSection
 	GlobalSection(SolutionProperties) = preSolution
 		HideSolutionNode = FALSE
@@ -1725,6 +1741,7 @@ Global
 		{46B4FE62-06A1-4D54-B3E8-D8B4B3560075} = {ACA6DDB9-7592-47CE-A740-D15BF307E9E0}
 		{92E11EBB-759E-4DA8-AB61-A9977D9F97D0} = {ACA6DDB9-7592-47CE-A740-D15BF307E9E0}
 		{D0CB733B-4CE8-4F6C-BBB9-548EA1A96966} = {D6FA4ABE-E685-4EDD-8B06-D8777E76B472}
+		{C4D624B3-749E-41D8-A43B-B304BC3885EA} = {4623F52E-2070-4631-8DEE-7D2F48733FFD}
 	EndGlobalSection
 	GlobalSection(ExtensibilityGlobals) = postSolution
 		SolutionGuid = {83786312-A93B-4BB4-AB06-7C6913A59AFA}

src/Middleware/WebSockets/src/HandshakeHelpers.cs

@@ -23,6 +23,15 @@ internal static class HandshakeHelpers
             HeaderNames.SecWebSocketVersion
         };
 
+        // "258EAFA5-E914-47DA-95CA-C5AB0DC85B11"
+        private static ReadOnlySpan<byte> _encodedWebSocketKey => new byte[]
+        {
+            (byte)'2', (byte)'5', (byte)'8', (byte)'E', (byte)'A', (byte)'F', (byte)'A', (byte)'5', (byte)'-',
+            (byte)'E', (byte)'9', (byte)'1', (byte)'4', (byte)'-', (byte)'4', (byte)'7', (byte)'D', (byte)'A',
+            (byte)'-', (byte)'9', (byte)'5', (byte)'C', (byte)'A', (byte)'-', (byte)'C', (byte)'5', (byte)'A',
+            (byte)'B', (byte)'0', (byte)'D', (byte)'C', (byte)'8', (byte)'5', (byte)'B', (byte)'1', (byte)'1'
+        };
+
         // Verify Method, Upgrade, Connection, version,  key, etc..
         public static bool CheckSupportedWebSocketRequest(string method, IEnumerable<KeyValuePair<string, string>> headers)
         {
@@ -87,34 +96,34 @@ public static bool IsRequestKeyValid(string value)
             {
                 return false;
             }
-            try
-            {
-                byte[] data = Convert.FromBase64String(value);
-                return data.Length == 16;
-            }
-            catch (Exception)
-            {
-                return false;
-            }
+
+            Span<byte> temp = stackalloc byte[16];
+            var success = Convert.TryFromBase64String(value, temp, out var written);
+            return success && written == 16;
         }
 
         public static string CreateResponseKey(string requestKey)
         {
             // "The value of this header field is constructed by concatenating /key/, defined above in step 4
-            // in Section 4.2.2, with the string "258EAFA5- E914-47DA-95CA-C5AB0DC85B11", taking the SHA-1 hash of
+            // in Section 4.2.2, with the string "258EAFA5-E914-47DA-95CA-C5AB0DC85B11", taking the SHA-1 hash of
             // this concatenated value to obtain a 20-byte value and base64-encoding"
             // https://tools.ietf.org/html/rfc6455#section-4.2.2
 
-            if (requestKey == null)
-            {
-                throw new ArgumentNullException(nameof(requestKey));
-            }
-
             using (var algorithm = SHA1.Create())
             {
-                string merged = requestKey + "258EAFA5-E914-47DA-95CA-C5AB0DC85B11";
-                byte[] mergedBytes = Encoding.UTF8.GetBytes(merged);
-                byte[] hashedBytes = algorithm.ComputeHash(mergedBytes);
+                // requestKey is already verified to be small (24 bytes) by 'IsRequestKeyValid()' and everything is 1:1 mapping to UTF8 bytes
+                // so this can be hardcoded to 60 bytes for the requestKey + static websocket string
+                Span<byte> mergedBytes = stackalloc byte[60];
+                Encoding.UTF8.GetBytes(requestKey, mergedBytes);
+                _encodedWebSocketKey.CopyTo(mergedBytes.Slice(24));
+
+                Span<byte> hashedBytes = stackalloc byte[20];
+                var success = algorithm.TryComputeHash(mergedBytes, hashedBytes, out var written);
+                if (!success || written != 20)
+                {
+                    throw new InvalidOperationException("Could not compute the hash for the 'Sec-WebSocket-Accept' header.");
+                }
+
                 return Convert.ToBase64String(hashedBytes);
             }
         }

src/Middleware/WebSockets/src/Microsoft.AspNetCore.WebSockets.csproj

@@ -1,4 +1,4 @@
-<Project Sdk="Microsoft.NET.Sdk">
+<Project Sdk="Microsoft.NET.Sdk">
 
   <PropertyGroup>
     <Description>ASP.NET Core web socket middleware for use on top of opaque servers.</Description>
@@ -17,4 +17,8 @@
     <Reference Include="Microsoft.Extensions.Options" />
   </ItemGroup>
 
+  <ItemGroup>
+    <InternalsVisibleTo Include="Microsoft.AspNetCore.WebSockets.Tests" />
+    <InternalsVisibleTo Include="Microsoft.AspNetCore.WebSockets.MicroBenchmarks" />
+  </ItemGroup>
 </Project>

src/Middleware/WebSockets/src/WebSocketMiddleware.cs

@@ -11,7 +11,6 @@
 using Microsoft.AspNetCore.Http;
 using Microsoft.AspNetCore.Http.Features;
 using Microsoft.Extensions.Logging;
-using Microsoft.Extensions.Logging.Abstractions;
 using Microsoft.Extensions.Options;
 using Microsoft.Extensions.Primitives;
 using Microsoft.Net.Http.Headers;
@@ -146,7 +145,7 @@ public async Task<WebSocket> AcceptAsync(WebSocketAcceptContext acceptContext)
                     }
                 }
 
-                string key = string.Join(", ", _context.Request.Headers[HeaderNames.SecWebSocketKey]);
+                string key = _context.Request.Headers[HeaderNames.SecWebSocketKey];
 
                 HandshakeHelpers.GenerateResponseHeaders(key, subProtocol, _context.Response.Headers);
 

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

@@ -0,0 +1,41 @@
+// Copyright (c) .NET Foundation. All rights reserved.
+// Licensed under the Apache License, Version 2.0. See License.txt in the project root for license information.
+
+using Xunit;
+
+namespace Microsoft.AspNetCore.WebSockets.Tests
+{
+    public class HandshakeTests
+    {
+        [Fact]
+        public void CreatesCorrectResponseKey()
+        {
+            // Example taken from https://tools.ietf.org/html/rfc6455#section-1.3
+            var key = "dGhlIHNhbXBsZSBub25jZQ==";
+            var expectedResponse = "s3pPLMBiTxaQ9kYGzzhZRbK+xOo=";
+
+            var response = HandshakeHelpers.CreateResponseKey(key);
+
+            Assert.Equal(expectedResponse, response);
+        }
+
+        [Theory]
+        [InlineData("VUfWn1u2Ot0AICM6f+/8Zg==")]
+        public void AcceptsValidRequestKeys(string key)
+        {
+            Assert.True(HandshakeHelpers.IsRequestKeyValid(key));
+        }
+
+        [Theory]
+        // 17 bytes when decoded
+        [InlineData("dGhpcyBpcyAxNyBieXRlcy4=")]
+        // 15 bytes when decoded
+        [InlineData("dGhpcyBpcyAxNWJ5dGVz")]
+        [InlineData("")]
+        [InlineData("24 length not base64 str")]
+        public void RejectsInvalidRequestKeys(string key)
+        {
+            Assert.False(HandshakeHelpers.IsRequestKeyValid(key));
+        }
+    }
+}

src/Middleware/perf/Microbenchmarks/AssemblyInfo.cs

@@ -0,0 +1 @@
+[assembly: BenchmarkDotNet.Attributes.AspNetCoreBenchmark]

src/Middleware/perf/Microbenchmarks/HandshakeBenchmark.cs

@@ -0,0 +1,41 @@
+// Copyright (c) .NET Foundation. All rights reserved.
+// Licensed under the Apache License, Version 2.0. See License.txt in the project root for license information.
+
+using BenchmarkDotNet.Attributes;
+
+namespace Microsoft.AspNetCore.WebSockets.Microbenchmarks
+{
+    public class HandshakeBenchmark
+    {
+        private string[] _requestKeys = {
+            "F8/qpj9RYr2/sIymdDvlmw==",
+            "PyQi8nyMkKnI7JKiAJ/IrA==",
+            "CUe0z8ItSBRtgJlPqP1+SQ==",
+            "w9vo1A9oM56M31qPQYKL6g==",
+            "+vqFGD9U04QOxKdWHrduTQ==",
+            "xsfuh2ZOm5O7zTzFPWJGUA==",
+            "TvmUzr4DgBLcDYX88kEAyw==",
+            "EZ5tcEOxWm7tF6adFXLSQg==",
+            "bkmoBhqwbbRzL8H9hvH1tQ==",
+            "EUwBrmmwivd5czsxz9eRzQ==",
+        };
+
+        [Benchmark(OperationsPerInvoke = 10)]
+        public void CreateResponseKey()
+        {
+            foreach (var key in _requestKeys)
+            {
+                HandshakeHelpers.CreateResponseKey(key);
+            }
+        }
+
+        [Benchmark(OperationsPerInvoke = 10)]
+        public void IsRequestKeyValid()
+        {
+            foreach (var key in _requestKeys)
+            {
+                HandshakeHelpers.IsRequestKeyValid(key);
+            }
+        }
+    }
+}

src/Middleware/perf/Microbenchmarks/Microsoft.AspNetCore.WebSockets.Microbenchmarks.csproj

@@ -0,0 +1,13 @@
+<Project Sdk="Microsoft.NET.Sdk">
+
+  <PropertyGroup>
+    <OutputType>Exe</OutputType>
+    <TargetFramework>$(DefaultNetCoreTargetFramework)</TargetFramework>
+  </PropertyGroup>
+
+  <ItemGroup>
+    <Reference Include="BenchmarkDotNet" />
+    <Reference Include="Microsoft.AspNetCore.BenchmarkRunner.Sources" />
+    <Reference Include="Microsoft.AspNetCore.WebSockets" />
+  </ItemGroup>
+</Project>