Using the optimized method for converting header name to ASCII

src/Microsoft.AspNetCore.Server.Kestrel/Http/FrameHeaders.Generated.cs

@@ -1,7 +1,7 @@
 
 using System;
 using System.Collections.Generic;
-using System.Text;
+using Microsoft.AspNetCore.Server.Kestrel.Exceptions;
 using Microsoft.AspNetCore.Server.Kestrel.Infrastructure;
 using Microsoft.Extensions.Primitives;
 
@@ -4198,6 +4198,7 @@ namespace Microsoft.AspNetCore.Server.Kestrel.Http
         
         public unsafe void Append(byte[] keyBytes, int keyOffset, int keyLength, string value)
         {
+            var key = new string('\0', keyLength);
             fixed (byte* ptr = &keyBytes[keyOffset])
             {
                 var pUB = ptr;
@@ -4898,8 +4899,16 @@ namespace Microsoft.AspNetCore.Server.Kestrel.Http
                         }
                         break;
                 }
+
+                fixed(char *keyBuffer = key)
+                {
+                    if (!AsciiUtilities.TryGetAsciiString(ptr, keyBuffer, keyLength))
+                    {
+                        throw new BadHttpRequestException("Invalid characters in header name");
+                    }
+                }
             }
-            var key = System.Text.Encoding.ASCII.GetString(keyBytes, keyOffset, keyLength);
+
             StringValues existing;
             Unknown.TryGetValue(key, out existing);
             Unknown[key] = AppendValue(existing, value);

test/Microsoft.AspNetCore.Server.KestrelTests/BadHttpRequestTests.cs

@@ -172,6 +172,23 @@ namespace Microsoft.AspNetCore.Server.KestrelTests
             }
         }
 
+        [Fact]
+        public async Task BadRequestWhenNameHeaderNamesContainsNonASCIICharacters()
+        {
+            using (var server = new TestServer(context => { return Task.FromResult(0); }))
+            {
+                using (var connection = server.CreateConnection())
+                {
+                    await connection.SendEnd(
+                        "GET / HTTP/1.1",
+                        "Hëädër: value",
+                        "",
+                        "");
+                    await ReceiveBadRequestResponse(connection);
+                }
+            }
+        }
+
         private async Task ReceiveBadRequestResponse(TestConnection connection)
         {
             await connection.Receive(

test/Microsoft.AspNetCore.Server.KestrelTests/FrameRequestHeadersTests.cs

@@ -1,5 +1,7 @@
 using System;
 using System.Collections.Generic;
+using System.Text;
+using Microsoft.AspNetCore.Server.Kestrel.Exceptions;
 using Microsoft.AspNetCore.Server.Kestrel.Http;
 using Microsoft.Extensions.Primitives;
 using Xunit;
@@ -233,5 +235,16 @@ namespace Microsoft.AspNetCore.Server.KestrelTests
             Assert.Null(entries[3].Key);
             Assert.Equal(new StringValues(), entries[0].Value);
         }
+
+        [Fact]
+        public void AppendThrowsWhenHeaderValueContainsNonASCIICharacters()
+        {
+            var headers = new FrameRequestHeaders();
+            const string key = "\u00141ód\017c";
+
+            var encoding = Encoding.GetEncoding("iso-8859-1");
+            Assert.Throws<BadHttpRequestException>(
+                () => headers.Append(encoding.GetBytes(key), 0, encoding.GetByteCount(key), key));
+        }
     }
 }

test/Microsoft.AspNetCore.Server.KestrelTests/TestConnection.cs

@@ -61,7 +61,7 @@ namespace Microsoft.AspNetCore.Server.KestrelTests
         public async Task Send(params string[] lines)
         {
             var text = String.Join("\r\n", lines);
-            var writer = new StreamWriter(_stream, Encoding.ASCII);
+            var writer = new StreamWriter(_stream, Encoding.GetEncoding("iso-8859-1"));
             for (var index = 0; index < text.Length; index++)
             {
                 var ch = text[index];

tools/Microsoft.AspNetCore.Server.Kestrel.GeneratedCode/KnownHeaders.cs

@@ -199,7 +199,7 @@ namespace Microsoft.AspNetCore.Server.Kestrel.GeneratedCode
             return $@"
 using System;
 using System.Collections.Generic;
-using System.Text;
+using Microsoft.AspNetCore.Server.Kestrel.Exceptions;
 using Microsoft.AspNetCore.Server.Kestrel.Infrastructure;
 using Microsoft.Extensions.Primitives;
 
@@ -418,6 +418,7 @@ namespace Microsoft.AspNetCore.Server.Kestrel.Http
         {(loop.ClassName == "FrameRequestHeaders" ? $@"
         public unsafe void Append(byte[] keyBytes, int keyOffset, int keyLength, string value)
         {{
+            var key = new string('\0', keyLength);
             fixed (byte* ptr = &keyBytes[keyOffset])
             {{
                 var pUB = ptr;
@@ -445,8 +446,16 @@ namespace Microsoft.AspNetCore.Server.Kestrel.Http
                         ")}}}
                         break;
                 ")}}}
+
+                fixed(char *keyBuffer = key)
+                {{
+                    if (!AsciiUtilities.TryGetAsciiString(ptr, keyBuffer, keyLength))
+                    {{
+                        throw new BadHttpRequestException(""Invalid characters in header name"");
+                    }}
+                }}
             }}
-            var key = System.Text.Encoding.ASCII.GetString(keyBytes, keyOffset, keyLength);
+
             StringValues existing;
             Unknown.TryGetValue(key, out existing);
             Unknown[key] = AppendValue(existing, value);