Add Request Decompression middleware

AspNetCore.sln

@@ -1658,6 +1658,13 @@ Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "Microsoft.AspNetCore.Compon
 EndProject
 Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "Microsoft.AspNetCore.Components.SdkAnalyzers.Tests", "src\Tools\SDK-Analyzers\Components\test\Microsoft.AspNetCore.Components.SdkAnalyzers.Tests.csproj", "{DC349A25-0DBF-4468-99E1-B95C22D3A7EF}"
 EndProject
+Project("{2150E333-8FDC-42A3-9474-1A3956D46DE8}") = "RequestDecompression", "RequestDecompression", "{5465F96F-33D5-454E-9C40-494E58AEEE5D}"
+EndProject
+Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "Microsoft.AspNetCore.RequestDecompression.Tests", "src\Middleware\RequestDecompression\test\Microsoft.AspNetCore.RequestDecompression.Tests.csproj", "{97996D39-7722-4AFC-A41A-AD61CA7A413D}"
+EndProject
+Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "RequestDecompressionSample", "src\Middleware\RequestDecompression\sample\RequestDecompressionSample.csproj", "{37144E52-611B-40E8-807C-2821F5A814CB}"
+EndProject
+Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "Microsoft.AspNetCore.RequestDecompression", "src\Middleware\RequestDecompression\src\Microsoft.AspNetCore.RequestDecompression.csproj", "{559FE354-7E08-4310-B4F3-AE30F34DEED5}"
 Project("{2150E333-8FDC-42A3-9474-1A3956D46DE8}") = "LinkabilityChecker", "LinkabilityChecker", "{94F95276-7CDF-44A8-B159-D09702EF6794}"
 EndProject
 Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "LinkabilityChecker", "src\Tools\LinkabilityChecker\LinkabilityChecker.csproj", "{EA7D844B-C180-41C7-9D55-273AD88BF71F}"
@@ -9938,6 +9945,54 @@ Global
 		{DC349A25-0DBF-4468-99E1-B95C22D3A7EF}.Release|x64.Build.0 = Release|Any CPU
 		{DC349A25-0DBF-4468-99E1-B95C22D3A7EF}.Release|x86.ActiveCfg = Release|Any CPU
 		{DC349A25-0DBF-4468-99E1-B95C22D3A7EF}.Release|x86.Build.0 = Release|Any CPU
+		{97996D39-7722-4AFC-A41A-AD61CA7A413D}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
+		{97996D39-7722-4AFC-A41A-AD61CA7A413D}.Debug|Any CPU.Build.0 = Debug|Any CPU
+		{97996D39-7722-4AFC-A41A-AD61CA7A413D}.Debug|arm64.ActiveCfg = Debug|Any CPU
+		{97996D39-7722-4AFC-A41A-AD61CA7A413D}.Debug|arm64.Build.0 = Debug|Any CPU
+		{97996D39-7722-4AFC-A41A-AD61CA7A413D}.Debug|x64.ActiveCfg = Debug|Any CPU
+		{97996D39-7722-4AFC-A41A-AD61CA7A413D}.Debug|x64.Build.0 = Debug|Any CPU
+		{97996D39-7722-4AFC-A41A-AD61CA7A413D}.Debug|x86.ActiveCfg = Debug|Any CPU
+		{97996D39-7722-4AFC-A41A-AD61CA7A413D}.Debug|x86.Build.0 = Debug|Any CPU
+		{97996D39-7722-4AFC-A41A-AD61CA7A413D}.Release|Any CPU.ActiveCfg = Release|Any CPU
+		{97996D39-7722-4AFC-A41A-AD61CA7A413D}.Release|Any CPU.Build.0 = Release|Any CPU
+		{97996D39-7722-4AFC-A41A-AD61CA7A413D}.Release|arm64.ActiveCfg = Release|Any CPU
+		{97996D39-7722-4AFC-A41A-AD61CA7A413D}.Release|arm64.Build.0 = Release|Any CPU
+		{97996D39-7722-4AFC-A41A-AD61CA7A413D}.Release|x64.ActiveCfg = Release|Any CPU
+		{97996D39-7722-4AFC-A41A-AD61CA7A413D}.Release|x64.Build.0 = Release|Any CPU
+		{97996D39-7722-4AFC-A41A-AD61CA7A413D}.Release|x86.ActiveCfg = Release|Any CPU
+		{97996D39-7722-4AFC-A41A-AD61CA7A413D}.Release|x86.Build.0 = Release|Any CPU
+		{37144E52-611B-40E8-807C-2821F5A814CB}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
+		{37144E52-611B-40E8-807C-2821F5A814CB}.Debug|Any CPU.Build.0 = Debug|Any CPU
+		{37144E52-611B-40E8-807C-2821F5A814CB}.Debug|arm64.ActiveCfg = Debug|Any CPU
+		{37144E52-611B-40E8-807C-2821F5A814CB}.Debug|arm64.Build.0 = Debug|Any CPU
+		{37144E52-611B-40E8-807C-2821F5A814CB}.Debug|x64.ActiveCfg = Debug|Any CPU
+		{37144E52-611B-40E8-807C-2821F5A814CB}.Debug|x64.Build.0 = Debug|Any CPU
+		{37144E52-611B-40E8-807C-2821F5A814CB}.Debug|x86.ActiveCfg = Debug|Any CPU
+		{37144E52-611B-40E8-807C-2821F5A814CB}.Debug|x86.Build.0 = Debug|Any CPU
+		{37144E52-611B-40E8-807C-2821F5A814CB}.Release|Any CPU.ActiveCfg = Release|Any CPU
+		{37144E52-611B-40E8-807C-2821F5A814CB}.Release|Any CPU.Build.0 = Release|Any CPU
+		{37144E52-611B-40E8-807C-2821F5A814CB}.Release|arm64.ActiveCfg = Release|Any CPU
+		{37144E52-611B-40E8-807C-2821F5A814CB}.Release|arm64.Build.0 = Release|Any CPU
+		{37144E52-611B-40E8-807C-2821F5A814CB}.Release|x64.ActiveCfg = Release|Any CPU
+		{37144E52-611B-40E8-807C-2821F5A814CB}.Release|x64.Build.0 = Release|Any CPU
+		{37144E52-611B-40E8-807C-2821F5A814CB}.Release|x86.ActiveCfg = Release|Any CPU
+		{37144E52-611B-40E8-807C-2821F5A814CB}.Release|x86.Build.0 = Release|Any CPU
+		{559FE354-7E08-4310-B4F3-AE30F34DEED5}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
+		{559FE354-7E08-4310-B4F3-AE30F34DEED5}.Debug|Any CPU.Build.0 = Debug|Any CPU
+		{559FE354-7E08-4310-B4F3-AE30F34DEED5}.Debug|arm64.ActiveCfg = Debug|Any CPU
+		{559FE354-7E08-4310-B4F3-AE30F34DEED5}.Debug|arm64.Build.0 = Debug|Any CPU
+		{559FE354-7E08-4310-B4F3-AE30F34DEED5}.Debug|x64.ActiveCfg = Debug|Any CPU
+		{559FE354-7E08-4310-B4F3-AE30F34DEED5}.Debug|x64.Build.0 = Debug|Any CPU
+		{559FE354-7E08-4310-B4F3-AE30F34DEED5}.Debug|x86.ActiveCfg = Debug|Any CPU
+		{559FE354-7E08-4310-B4F3-AE30F34DEED5}.Debug|x86.Build.0 = Debug|Any CPU
+		{559FE354-7E08-4310-B4F3-AE30F34DEED5}.Release|Any CPU.ActiveCfg = Release|Any CPU
+		{559FE354-7E08-4310-B4F3-AE30F34DEED5}.Release|Any CPU.Build.0 = Release|Any CPU
+		{559FE354-7E08-4310-B4F3-AE30F34DEED5}.Release|arm64.ActiveCfg = Release|Any CPU
+		{559FE354-7E08-4310-B4F3-AE30F34DEED5}.Release|arm64.Build.0 = Release|Any CPU
+		{559FE354-7E08-4310-B4F3-AE30F34DEED5}.Release|x64.ActiveCfg = Release|Any CPU
+		{559FE354-7E08-4310-B4F3-AE30F34DEED5}.Release|x64.Build.0 = Release|Any CPU
+		{559FE354-7E08-4310-B4F3-AE30F34DEED5}.Release|x86.ActiveCfg = Release|Any CPU
+		{559FE354-7E08-4310-B4F3-AE30F34DEED5}.Release|x86.Build.0 = Release|Any CPU
 		{EA7D844B-C180-41C7-9D55-273AD88BF71F}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
 		{EA7D844B-C180-41C7-9D55-273AD88BF71F}.Debug|Any CPU.Build.0 = Debug|Any CPU
 		{EA7D844B-C180-41C7-9D55-273AD88BF71F}.Debug|arm64.ActiveCfg = Debug|Any CPU
@@ -10774,6 +10829,10 @@ Global
 		{CC45FA2D-128B-485D-BA6D-DFD9735CB3C3} = {6C06163A-80E9-49C1-817C-B391852BA563}
 		{825BCF97-67A9-4834-B3A8-C3DC97A90E41} = {CC45FA2D-128B-485D-BA6D-DFD9735CB3C3}
 		{DC349A25-0DBF-4468-99E1-B95C22D3A7EF} = {CC45FA2D-128B-485D-BA6D-DFD9735CB3C3}
+		{5465F96F-33D5-454E-9C40-494E58AEEE5D} = {E5963C9F-20A6-4385-B364-814D2581FADF}
+		{97996D39-7722-4AFC-A41A-AD61CA7A413D} = {5465F96F-33D5-454E-9C40-494E58AEEE5D}
+		{37144E52-611B-40E8-807C-2821F5A814CB} = {5465F96F-33D5-454E-9C40-494E58AEEE5D}
+		{559FE354-7E08-4310-B4F3-AE30F34DEED5} = {5465F96F-33D5-454E-9C40-494E58AEEE5D}
 		{94F95276-7CDF-44A8-B159-D09702EF6794} = {0B200A66-B809-4ED3-A790-CB1C2E80975E}
 		{EA7D844B-C180-41C7-9D55-273AD88BF71F} = {94F95276-7CDF-44A8-B159-D09702EF6794}
 	EndGlobalSection

eng/ProjectReferences.props

@@ -89,6 +89,7 @@
     <ProjectReferenceProvider Include="Microsoft.AspNetCore.Localization.Routing" ProjectPath="$(RepoRoot)src\Middleware\Localization.Routing\src\Microsoft.AspNetCore.Localization.Routing.csproj" />
     <ProjectReferenceProvider Include="Microsoft.AspNetCore.Localization" ProjectPath="$(RepoRoot)src\Middleware\Localization\src\Microsoft.AspNetCore.Localization.csproj" />
     <ProjectReferenceProvider Include="Microsoft.AspNetCore.MiddlewareAnalysis" ProjectPath="$(RepoRoot)src\Middleware\MiddlewareAnalysis\src\Microsoft.AspNetCore.MiddlewareAnalysis.csproj" />
+    <ProjectReferenceProvider Include="Microsoft.AspNetCore.RequestDecompression" ProjectPath="$(RepoRoot)src\Middleware\RequestDecompression\src\Microsoft.AspNetCore.RequestDecompression.csproj" />
     <ProjectReferenceProvider Include="Microsoft.AspNetCore.ResponseCaching.Abstractions" ProjectPath="$(RepoRoot)src\Middleware\ResponseCaching.Abstractions\src\Microsoft.AspNetCore.ResponseCaching.Abstractions.csproj" />
     <ProjectReferenceProvider Include="Microsoft.AspNetCore.ResponseCaching" ProjectPath="$(RepoRoot)src\Middleware\ResponseCaching\src\Microsoft.AspNetCore.ResponseCaching.csproj" />
     <ProjectReferenceProvider Include="Microsoft.AspNetCore.ResponseCompression" ProjectPath="$(RepoRoot)src\Middleware\ResponseCompression\src\Microsoft.AspNetCore.ResponseCompression.csproj" />

eng/SharedFramework.Local.props

@@ -77,6 +77,7 @@
     <AspNetCoreAppReference Include="Microsoft.AspNetCore.HttpsPolicy" />
     <AspNetCoreAppReference Include="Microsoft.AspNetCore.Localization.Routing" />
     <AspNetCoreAppReference Include="Microsoft.AspNetCore.Localization" />
+    <AspNetCoreAppReference Include="Microsoft.AspNetCore.RequestDecompression" />
     <AspNetCoreAppReference Include="Microsoft.AspNetCore.ResponseCaching.Abstractions" />
     <AspNetCoreAppReference Include="Microsoft.AspNetCore.ResponseCaching" />
     <AspNetCoreAppReference Include="Microsoft.AspNetCore.ResponseCompression" />

src/Framework/test/TestData.cs

@@ -75,6 +75,7 @@ static TestData()
                 "Microsoft.AspNetCore.Mvc.ViewFeatures",
                 "Microsoft.AspNetCore.Razor",
                 "Microsoft.AspNetCore.Razor.Runtime",
+                "Microsoft.AspNetCore.RequestDecompression",
                 "Microsoft.AspNetCore.ResponseCaching",
                 "Microsoft.AspNetCore.ResponseCaching.Abstractions",
                 "Microsoft.AspNetCore.ResponseCompression",
@@ -210,6 +211,7 @@ static TestData()
                 { "Microsoft.AspNetCore.Mvc.ViewFeatures", "7.0.0.0" },
                 { "Microsoft.AspNetCore.Razor", "7.0.0.0" },
                 { "Microsoft.AspNetCore.Razor.Runtime", "7.0.0.0" },
+                { "Microsoft.AspNetCore.RequestDecompression", "7.0.0.0" },
                 { "Microsoft.AspNetCore.ResponseCaching", "7.0.0.0" },
                 { "Microsoft.AspNetCore.ResponseCaching.Abstractions", "7.0.0.0" },
                 { "Microsoft.AspNetCore.ResponseCompression", "7.0.0.0" },

src/Http/Http.Abstractions/src/Metadata/IRequestSizeLimitMetadata.cs

@@ -0,0 +1,15 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+
+namespace Microsoft.AspNetCore.Http.Metadata;
+
+/// <summary>
+/// Interface marking attributes that specify the maximum allowed size of the request body.
+/// </summary>
+public interface IRequestSizeLimitMetadata
+{
+    /// <summary>
+    /// The maximum allowed size of the current request body in bytes.
+    /// </summary>
+    long MaxRequestBodySize { get; }
+}

src/Http/Http.Abstractions/src/PublicAPI.Unshipped.txt

@@ -3,5 +3,7 @@
 Microsoft.AspNetCore.Http.EndpointMetadataCollection.GetRequiredMetadata<T>() -> T!
 Microsoft.AspNetCore.Http.Metadata.IFromFormMetadata
 Microsoft.AspNetCore.Http.Metadata.IFromFormMetadata.Name.get -> string?
+Microsoft.AspNetCore.Http.Metadata.IRequestSizeLimitMetadata
+Microsoft.AspNetCore.Http.Metadata.IRequestSizeLimitMetadata.MaxRequestBodySize.get -> long
 abstract Microsoft.AspNetCore.Http.HttpResponse.ContentType.get -> string?
 Microsoft.AspNetCore.Http.Metadata.ISkipStatusCodePagesMetadata

src/Middleware/Middleware.slnf

@@ -76,6 +76,9 @@
       "src\\Middleware\\MiddlewareAnalysis\\samples\\MiddlewareAnalysisSample\\MiddlewareAnalysisSample.csproj",
       "src\\Middleware\\MiddlewareAnalysis\\src\\Microsoft.AspNetCore.MiddlewareAnalysis.csproj",
       "src\\Middleware\\MiddlewareAnalysis\\test\\Microsoft.AspNetCore.MiddlewareAnalysis.Tests.csproj",
+      "src\\Middleware\\RequestDecompression\\sample\\RequestDecompressionSample.csproj",
+      "src\\Middleware\\RequestDecompression\\src\\Microsoft.AspNetCore.RequestDecompression.csproj",
+      "src\\Middleware\\RequestDecompression\\test\\Microsoft.AspNetCore.RequestDecompression.Tests.csproj",
       "src\\Middleware\\ResponseCaching.Abstractions\\src\\Microsoft.AspNetCore.ResponseCaching.Abstractions.csproj",
       "src\\Middleware\\ResponseCaching\\samples\\ResponseCachingSample\\ResponseCachingSample.csproj",
       "src\\Middleware\\ResponseCaching\\src\\Microsoft.AspNetCore.ResponseCaching.csproj",
@@ -115,4 +118,4 @@
       "src\\Servers\\Kestrel\\Transport.Sockets\\src\\Microsoft.AspNetCore.Server.Kestrel.Transport.Sockets.csproj"
     ]
   }
-}
+}

src/Middleware/RequestDecompression/sample/CustomDecompressionProvider.cs

@@ -0,0 +1,15 @@
+// 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.RequestDecompression;
+
+namespace RequestDecompressionSample;
+
+public class CustomDecompressionProvider : IDecompressionProvider
+{
+    public Stream GetDecompressionStream(Stream stream)
+    {
+        // Create a custom decompression stream wrapper here.
+        return stream;
+    }
+}

src/Middleware/RequestDecompression/sample/Properties/launchsettings.json

@@ -0,0 +1,27 @@
+{
+    "iisSettings": {
+      "windowsAuthentication": false,
+      "anonymousAuthentication": true,
+      "iisExpress": {
+        "applicationUrl": "http://localhost:6164/",
+        "sslPort": 0
+      }
+    },
+    "profiles": {
+      "RequestDecompressionSample": {
+        "commandName": "Project",
+        "launchBrowser": true,
+        "launchUrl": "http://localhost:5000/",
+        "environmentVariables": {
+          "ASPNETCORE_ENVIRONMENT": "Development"
+        }
+      },
+      "IIS Express": {
+        "commandName": "IISExpress",
+        "launchBrowser": true,
+        "environmentVariables": {
+          "ASPNETCORE_ENVIRONMENT": "Development"
+        }
+      }
+    }
+  }

src/Middleware/RequestDecompression/sample/RequestDecompressionSample.csproj

@@ -0,0 +1,13 @@
+<Project Sdk="Microsoft.NET.Sdk.Web">
+
+  <PropertyGroup>
+    <TargetFramework>$(DefaultNetCoreTargetFramework)</TargetFramework>
+  </PropertyGroup>
+
+  <ItemGroup>
+    <Reference Include="Microsoft.AspNetCore.RequestDecompression" />
+    <Reference Include="Microsoft.AspNetCore.Server.Kestrel" />
+    <Reference Include="Microsoft.Extensions.Logging.Console" />
+  </ItemGroup>
+
+</Project>

src/Middleware/RequestDecompression/sample/Startup.cs

@@ -0,0 +1,48 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+
+namespace RequestDecompressionSample;
+
+public class Startup
+{
+    public void ConfigureServices(IServiceCollection services)
+    {
+        services.AddRequestDecompression(options =>
+        {
+            options.DecompressionProviders.Add("custom", new CustomDecompressionProvider());
+        });
+    }
+
+    public void Configure(IApplicationBuilder app)
+    {
+        app.UseRequestDecompression();
+        app.Map("/test", testApp =>
+        {
+            testApp.Run(async context =>
+            {
+                using var reader = new StreamReader(context.Request.Body);
+                var decompressedBody = await reader.ReadToEndAsync(context.RequestAborted);
+
+                await context.Response.WriteAsync(decompressedBody, context.RequestAborted);
+            });
+        });
+    }
+
+    public static Task Main(string[] args)
+    {
+        var host = new HostBuilder()
+            .ConfigureWebHost(webHostBuilder =>
+            {
+                webHostBuilder
+                .UseKestrel()
+                .ConfigureLogging(factory =>
+                {
+                    factory.AddConsole()
+                    .SetMinimumLevel(LogLevel.Debug);
+                })
+                .UseStartup<Startup>();
+            }).Build();
+
+        return host.RunAsync();
+    }
+}

src/Middleware/RequestDecompression/src/BrotliDecompressionProvider.cs

@@ -0,0 +1,18 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+
+using System.IO.Compression;
+
+namespace Microsoft.AspNetCore.RequestDecompression;
+
+/// <summary>
+/// Brotli decompression provider.
+/// </summary>
+internal sealed class BrotliDecompressionProvider : IDecompressionProvider
+{
+    /// <inheritdoc />
+    public Stream GetDecompressionStream(Stream stream)
+    {
+        return new BrotliStream(stream, CompressionMode.Decompress, leaveOpen: true);
+    }
+}

src/Middleware/RequestDecompression/src/DefaultRequestDecompressionProvider.cs

@@ -0,0 +1,90 @@
+// 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.Http;
+using Microsoft.Extensions.Logging;
+using Microsoft.Extensions.Options;
+using Microsoft.Extensions.Primitives;
+using Microsoft.Net.Http.Headers;
+
+namespace Microsoft.AspNetCore.RequestDecompression;
+
+/// <inheritdoc />
+internal sealed partial class DefaultRequestDecompressionProvider : IRequestDecompressionProvider
+{
+    private readonly ILogger _logger;
+    private readonly IDictionary<string, IDecompressionProvider> _providers;
+
+    public DefaultRequestDecompressionProvider(
+        ILogger<DefaultRequestDecompressionProvider> logger,
+        IOptions<RequestDecompressionOptions> options)
+    {
+        if (logger is null)
+        {
+            throw new ArgumentNullException(nameof(logger));
+        }
+
+        if (options is null)
+        {
+            throw new ArgumentNullException(nameof(options));
+        }
+
+        _logger = logger;
+        _providers = options.Value.DecompressionProviders;
+    }
+
+    /// <inheritdoc />
+    public Stream? GetDecompressionStream(HttpContext context)
+    {
+        var encodings = context.Request.Headers.ContentEncoding;
+
+        if (StringValues.IsNullOrEmpty(encodings))
+        {
+            Log.NoContentEncoding(_logger);
+            return null;
+        }
+
+        if (encodings.Count > 1)
+        {
+            Log.MultipleContentEncodingsSpecified(_logger);
+            return null;
+        }
+
+        string encodingName = encodings!;
+
+        if (_providers.TryGetValue(encodingName, out var matchingProvider))
+        {
+            Log.DecompressingWith(_logger, encodingName);
+
+            context.Request.Headers.Remove(HeaderNames.ContentEncoding);
+
+            return matchingProvider.GetDecompressionStream(context.Request.Body);
+        }
+
+        Log.NoDecompressionProvider(_logger);
+        return null;
+    }
+
+    private static partial class Log
+    {
+        [LoggerMessage(1, LogLevel.Trace, "The Content-Encoding header is empty or not specified. Skipping request decompression.", EventName = "NoContentEncoding")]
+        public static partial void NoContentEncoding(ILogger logger);
+
+        [LoggerMessage(2, LogLevel.Debug, "Request decompression is not supported for multiple Content-Encodings.", EventName = "MultipleContentEncodingsSpecified")]
+        public static partial void MultipleContentEncodingsSpecified(ILogger logger);
+
+        [LoggerMessage(3, LogLevel.Debug, "No matching request decompression provider found.", EventName = "NoDecompressionProvider")]
+        public static partial void NoDecompressionProvider(ILogger logger);
+
+        public static void DecompressingWith(ILogger logger, string contentEncoding)
+        {
+            if (logger.IsEnabled(LogLevel.Debug)
+            {
+                DecompressingWithCore(logger, contentEncoding.ToLowerInvariant());
+            }
+        }
+
+        [LoggerMessage(4, LogLevel.Debug, "The request will be decompressed with '{ContentEncoding}'.", EventName = "DecompressingWith", SkipEnabledCheck = true)]
+        private static partial void DecompressingWithCore(ILogger logger, string contentEncoding);
+    }
+}

src/Middleware/RequestDecompression/src/DeflateDecompressionProvider.cs

@@ -0,0 +1,18 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+
+using System.IO.Compression;
+
+namespace Microsoft.AspNetCore.RequestDecompression;
+
+/// <summary>
+/// DEFLATE decompression provider.
+/// </summary>
+internal sealed class DeflateDecompressionProvider : IDecompressionProvider
+{
+    /// <inheritdoc />
+    public Stream GetDecompressionStream(Stream stream)
+    {
+        return new DeflateStream(stream, CompressionMode.Decompress, leaveOpen: true);
+    }
+}