From 991cfa8bd8ed940be32ffeda39f8beeb992c9c02 Mon Sep 17 00:00:00 2001
From: "Chris Ross (ASP.NET)" <chrross@microsoft.com>
Date: Sat, 1 Sep 2018 20:20:52 -0700
Subject: [PATCH] Remove limits on SETTINGS_HEADER_TABLE_SIZE #2874

---
 src/Kestrel.Core/Http2Limits.cs               |  8 ++++----
 .../Internal/Http2/Http2PeerSettings.cs       |  6 ------
 .../Http2/Http2ConnectionTests.cs             | 19 ++++++++++++++++++-
 3 files changed, 22 insertions(+), 11 deletions(-)

diff --git a/src/Kestrel.Core/Http2Limits.cs b/src/Kestrel.Core/Http2Limits.cs
index f4b05c4abb..bf30a0c414 100644
--- a/src/Kestrel.Core/Http2Limits.cs
+++ b/src/Kestrel.Core/Http2Limits.cs
@@ -2,6 +2,7 @@
 // Licensed under the Apache License, Version 2.0. See License.txt in the project root for license information.
 
 using System;
+using Microsoft.AspNetCore.Server.Kestrel.Core.Internal.Http2;
 
 namespace Microsoft.AspNetCore.Server.Kestrel.Core
 {
@@ -11,11 +12,10 @@ namespace Microsoft.AspNetCore.Server.Kestrel.Core
     public class Http2Limits
     {
         private int _maxStreamsPerConnection = 100;
-        private int _headerTableSize = MaxAllowedHeaderTableSize;
+        private int _headerTableSize = (int)Http2PeerSettings.DefaultHeaderTableSize;
         private int _maxFrameSize = MinAllowedMaxFrameSize;
 
         // These are limits defined by the RFC https://tools.ietf.org/html/rfc7540#section-4.2
-        public const int MaxAllowedHeaderTableSize = 4096;
         public const int MinAllowedMaxFrameSize = 16 * 1024;
         public const int MaxAllowedMaxFrameSize = 16 * 1024 * 1024 - 1;
 
@@ -50,9 +50,9 @@ namespace Microsoft.AspNetCore.Server.Kestrel.Core
             get => _headerTableSize;
             set
             {
-                if (value <= 0 || value > MaxAllowedHeaderTableSize)
+                if (value <= 0)
                 {
-                    throw new ArgumentOutOfRangeException(nameof(value), value, CoreStrings.FormatArgumentOutOfRange(0, MaxAllowedHeaderTableSize));
+                    throw new ArgumentOutOfRangeException(nameof(value), value, CoreStrings.GreaterThanZeroRequired);
                 }
 
                 _headerTableSize = value;
diff --git a/src/Kestrel.Core/Internal/Http2/Http2PeerSettings.cs b/src/Kestrel.Core/Internal/Http2/Http2PeerSettings.cs
index e821daac13..f11fed9ca7 100644
--- a/src/Kestrel.Core/Internal/Http2/Http2PeerSettings.cs
+++ b/src/Kestrel.Core/Internal/Http2/Http2PeerSettings.cs
@@ -38,12 +38,6 @@ namespace Microsoft.AspNetCore.Server.Kestrel.Core.Internal.Http2
                 switch (setting.Parameter)
                 {
                     case Http2SettingsParameter.SETTINGS_HEADER_TABLE_SIZE:
-                        if (value > Http2Limits.MaxAllowedHeaderTableSize)
-                        {
-                            throw new Http2SettingsParameterOutOfRangeException(Http2SettingsParameter.SETTINGS_HEADER_TABLE_SIZE,
-                                lowerBound: 0,
-                                upperBound: Http2Limits.MaxAllowedHeaderTableSize);
-                        }
                         HeaderTableSize = value;
                         break;
                     case Http2SettingsParameter.SETTINGS_ENABLE_PUSH:
diff --git a/test/Kestrel.InMemory.FunctionalTests/Http2/Http2ConnectionTests.cs b/test/Kestrel.InMemory.FunctionalTests/Http2/Http2ConnectionTests.cs
index f876a1f01b..0d599b75ca 100644
--- a/test/Kestrel.InMemory.FunctionalTests/Http2/Http2ConnectionTests.cs
+++ b/test/Kestrel.InMemory.FunctionalTests/Http2/Http2ConnectionTests.cs
@@ -2100,7 +2100,6 @@ namespace Microsoft.AspNetCore.Server.Kestrel.Core.Tests
         [InlineData(Http2SettingsParameter.SETTINGS_MAX_FRAME_SIZE, 16 * 1024 - 1, Http2ErrorCode.PROTOCOL_ERROR)]
         [InlineData(Http2SettingsParameter.SETTINGS_MAX_FRAME_SIZE, 16 * 1024 * 1024, Http2ErrorCode.PROTOCOL_ERROR)]
         [InlineData(Http2SettingsParameter.SETTINGS_MAX_FRAME_SIZE, uint.MaxValue, Http2ErrorCode.PROTOCOL_ERROR)]
-        [InlineData(Http2SettingsParameter.SETTINGS_HEADER_TABLE_SIZE, 4097, Http2ErrorCode.PROTOCOL_ERROR)]
         public async Task SETTINGS_Received_InvalidParameterValue_ConnectionError(Http2SettingsParameter parameter, uint value, Http2ErrorCode expectedErrorCode)
         {
             await InitializeConnectionAsync(_noopApplication);
@@ -2242,6 +2241,24 @@ namespace Microsoft.AspNetCore.Server.Kestrel.Core.Tests
             await StopConnectionAsync(expectedLastStreamId: 1, ignoreNonGoAwayFrames: false);
         }
 
+        [Fact]
+        public async Task SETTINGS_Received_ChangesHeaderTableSize()
+        {
+            await InitializeConnectionAsync(_noopApplication);
+
+            // Update client settings
+            _clientSettings.HeaderTableSize = 65536; // Chrome's default, larger than the 4kb spec default
+            await SendSettingsAsync();
+
+            // ACK
+            await ExpectAsync(Http2FrameType.SETTINGS,
+                withLength: 0,
+                withFlags: (byte)Http2SettingsFrameFlags.ACK,
+                withStreamId: 0);
+
+            await StopConnectionAsync(expectedLastStreamId: 0, ignoreNonGoAwayFrames: false);
+        }
+
         [Fact]
         public async Task PUSH_PROMISE_Received_ConnectionError()
         {