Use TimeProvider to set HttpContext.Timestamp

src/Microsoft.AspNetCore.SystemWebAdapters.CoreServices/Authentication/RemoteAppAuthenticationAuthHandler.cs

@@ -29,9 +29,13 @@ public RemoteAppAuthenticationAuthHandler(IRemoteAppAuthenticationService authSe
                                            IEnumerable<IRemoteAppAuthenticationResultProcessor> resultProcessors,
                                            IOptionsMonitor<RemoteAppAuthenticationClientOptions> options,
                                            ILoggerFactory loggerFactory,
-                                           UrlEncoder encoder,
-                                           ISystemClock clock)
+                                           UrlEncoder encoder
+#if NET8_0_OR_GREATER
+        ) : base(options, loggerFactory, encoder)
+#else
+        , ISystemClock clock)
         : base(options, loggerFactory, encoder, clock)
+#endif
     {
         _logger = loggerFactory.CreateLogger<RemoteAppAuthenticationAuthHandler>();
         _authService = authService;

src/Microsoft.AspNetCore.SystemWebAdapters.CoreServices/Authentication/RemoteAppAuthenticationResultFactory.cs

@@ -8,6 +8,7 @@
 using System.Net.Http;
 using System.Security.Claims;
 using System.Threading.Tasks;
+using Microsoft.AspNetCore.Http;
 
 namespace Microsoft.AspNetCore.SystemWebAdapters.Authentication;
 
@@ -44,7 +45,7 @@ public async Task<RemoteAppAuthenticationResult> CreateRemoteAppAuthenticationRe
         {
             if (forwardAllResponseHeaders || options.ResponseHeadersToForward.Contains(responseHeader.Key))
             {
-                ret.ResponseHeaders.Add(responseHeader.Key, responseHeader.Value.ToArray());
+                ret.ResponseHeaders.AppendList(responseHeader.Key, responseHeader.Value.ToList());
             }
         }
 

src/Microsoft.AspNetCore.SystemWebAdapters.CoreServices/Authentication/ResultProcessors/RedirectUrlProcessor.cs

@@ -43,7 +43,7 @@ public Task ProcessAsync(RemoteAppAuthenticationResult result, HttpContext conte
                 }
             }
             result.ResponseHeaders.Remove(LocationHeaderName);
-            result.ResponseHeaders.Add(LocationHeaderName, processedRedirectLocations.ToArray());
+            result.ResponseHeaders.AppendList(LocationHeaderName, processedRedirectLocations);
         }
 
         return Task.CompletedTask;

src/Microsoft.AspNetCore.SystemWebAdapters.CoreServices/Microsoft.AspNetCore.SystemWebAdapters.CoreServices.csproj

@@ -1,6 +1,6 @@
 <Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
-    <TargetFrameworks>net6.0;net7.0</TargetFrameworks>
+    <TargetFrameworks>net6.0;net7.0;net8.0</TargetFrameworks>
     <IsPackable>true</IsPackable>
     <EnablePackageValidation>true</EnablePackageValidation>
     <RootNamespace>Microsoft.AspNetCore.SystemWebAdapters</RootNamespace>
@@ -16,6 +16,9 @@
   <ItemGroup>
     <FrameworkReference Include="Microsoft.AspNetCore.App" />
   </ItemGroup>
+  <ItemGroup Condition=" '$(TargetFramework)' == 'net6.0' OR '$(TargetFramework)' == 'net7.0' ">
+    <PackageReference Include="Microsoft.Bcl.TimeProvider" Version="8.0.0-rc.1.23419.4" />
+  </ItemGroup>
   <ItemGroup>
     <Using Include="Microsoft.AspNetCore.Http.HttpContext" Alias="HttpContextCore" />
     <Using Include="Microsoft.AspNetCore.Http.HttpResponse" Alias="HttpResponseCore" />

src/Microsoft.AspNetCore.SystemWebAdapters.CoreServices/SessionState/RemoteSession/RemoteAppSessionStateManager.cs

@@ -8,6 +8,7 @@
 using System.Net.Http;
 using System.Threading;
 using System.Threading.Tasks;
+using Microsoft.AspNetCore.Http;
 using Microsoft.AspNetCore.SystemWebAdapters.SessionState.Serialization;
 using Microsoft.Extensions.Logging;
 using Microsoft.Extensions.Options;
@@ -130,7 +131,7 @@ private static void PropagateHeaders(HttpResponseMessage responseMessage, HttpCo
     {
         if (context?.Response is not null && responseMessage.Headers.TryGetValues(cookieName, out var cookieValues))
         {
-            context.Response.Headers.Add(cookieName, cookieValues.ToArray());
+            context.Response.Headers.AppendList(cookieName, cookieValues.ToArray());
         }
     }
 

src/Microsoft.AspNetCore.SystemWebAdapters.CoreServices/SetHttpContextTimestampMiddleware.cs

@@ -1,6 +1,7 @@
 // Licensed to the .NET Foundation under one or more agreements.
 // The .NET Foundation licenses this file to you under the MIT license.
 
+using System;
 using System.Threading.Tasks;
 using Microsoft.AspNetCore.Http;
 
@@ -9,14 +10,26 @@ namespace Microsoft.AspNetCore.SystemWebAdapters;
 internal class SetHttpContextTimestampMiddleware
 {
     private readonly RequestDelegate _next;
+    private readonly TimeProvider _timeProvider;
 
-    public SetHttpContextTimestampMiddleware(RequestDelegate next) => _next = next;
+    public SetHttpContextTimestampMiddleware(TimeProvider timeProvider, RequestDelegate next)
+    {
+        _timeProvider = timeProvider;
+        _next = next;
+    }
 
     public Task InvokeAsync(HttpContext context)
     {
-        // Ensure adapter is created to force timestamp to be set
-        _ = context.GetAdapter();
+        context.Features.Set<TimestampFeature>(new(_timeProvider));
 
         return _next(context);
     }
+
+    private sealed class TimestampFeature : ITimestampFeature
+    {
+        public TimestampFeature(TimeProvider timeProvider)
+            => Timestamp = timeProvider.GetLocalNow();
+
+        public DateTimeOffset Timestamp { get; }
+    }
 }

src/Microsoft.AspNetCore.SystemWebAdapters.CoreServices/SystemWebAdaptersExtensions.cs

@@ -8,6 +8,7 @@
 using Microsoft.AspNetCore.Builder;
 using Microsoft.AspNetCore.Hosting;
 using Microsoft.AspNetCore.SystemWebAdapters;
+using Microsoft.Extensions.DependencyInjection.Extensions;
 using Microsoft.Extensions.Logging;
 
 namespace Microsoft.Extensions.DependencyInjection;
@@ -17,6 +18,7 @@ public static class SystemWebAdaptersExtensions
     public static ISystemWebAdapterBuilder AddSystemWebAdapters(this IServiceCollection services)
     {
         services.AddHttpContextAccessor();
+        services.TryAddSingleton(TimeProvider.System);
         services.AddSingleton<Cache>();
         services.AddSingleton<IBrowserCapabilitiesFactory, BrowserCapabilitiesFactory>();
         services.AddTransient<IStartupFilter, HttpContextStartupFilter>();

src/Microsoft.AspNetCore.SystemWebAdapters/Adapters/ITimestampFeature.cs

@@ -0,0 +1,13 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+
+#if NET6_0_OR_GREATER
+using System;
+
+namespace Microsoft.AspNetCore.SystemWebAdapters;
+
+internal interface ITimestampFeature
+{
+    DateTimeOffset Timestamp { get; }
+}
+#endif

src/Microsoft.AspNetCore.SystemWebAdapters/Generated/Ref.Standard.cs

@@ -147,7 +147,7 @@ internal HttpContext() { }
         public System.Web.HttpResponse Response { get { throw new System.PlatformNotSupportedException("Only supported when running on ASP.NET Core or System.Web");} }
         public System.Web.HttpServerUtility Server { get { throw new System.PlatformNotSupportedException("Only supported when running on ASP.NET Core or System.Web");} }
         public System.Web.SessionState.HttpSessionState Session { get { throw new System.PlatformNotSupportedException("Only supported when running on ASP.NET Core or System.Web");} }
-        public System.DateTime Timestamp { [System.Runtime.CompilerServices.CompilerGeneratedAttribute]get { throw new System.PlatformNotSupportedException("Only supported when running on ASP.NET Core or System.Web");} }
+        public System.DateTime Timestamp { get { throw new System.PlatformNotSupportedException("Only supported when running on ASP.NET Core or System.Web");} }
         public System.Web.TraceContext Trace { get { throw new System.PlatformNotSupportedException("Only supported when running on ASP.NET Core or System.Web");} }
         public System.Security.Principal.IPrincipal User { get { throw new System.PlatformNotSupportedException("Only supported when running on ASP.NET Core or System.Web");} set { throw new System.PlatformNotSupportedException("Only supported when running on ASP.NET Core or System.Web");} }
         public void AddError(System.Exception ex) { throw new System.PlatformNotSupportedException("Only supported when running on ASP.NET Core or System.Web");}

src/Microsoft.AspNetCore.SystemWebAdapters/HttpContext.cs

@@ -90,7 +90,7 @@ public IPrincipal User
 
     public HttpSessionState? Session => _context.Features.Get<HttpSessionState>();
 
-    public DateTime Timestamp { get; } = DateTime.UtcNow.ToLocalTime();
+    public DateTime Timestamp => _context.Features.GetRequired<ITimestampFeature>().Timestamp.DateTime;
 
     public void RewritePath(string path) => RewritePath(path, true);
 

test/Microsoft.AspNetCore.SystemWebAdapters.CoreServices.Tests/Microsoft.AspNetCore.SystemWebAdapters.CoreServices.Tests.csproj

@@ -1,6 +1,6 @@
 <Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
-    <TargetFrameworks>net6.0</TargetFrameworks>
+    <TargetFrameworks>net6.0;net8.0</TargetFrameworks>
   </PropertyGroup>
   <ItemGroup>
     <PackageReference Include="Autofac.Extras.Moq" Version="6.0.0" />