Add HTTP/2 pseudo headers as known headers (#19457)

src/Servers/Kestrel/Core/src/Internal/Http2/Http2Stream.cs

@@ -187,7 +187,7 @@ namespace Microsoft.AspNetCore.Server.Kestrel.Core.Internal.Http2
             // CONNECT - :scheme and :path must be excluded
             if (Method == HttpMethod.Connect)
             {
-                if (!String.IsNullOrEmpty(RequestHeaders[HeaderNames.Scheme]) || !String.IsNullOrEmpty(RequestHeaders[HeaderNames.Path]))
+                if (!String.IsNullOrEmpty(HttpRequestHeaders.HeaderScheme) || !String.IsNullOrEmpty(HttpRequestHeaders.HeaderPath))
                 {
                     ResetAndAbort(new ConnectionAbortedException(CoreStrings.Http2ErrorConnectMustNotSendSchemeOrPath), Http2ErrorCode.PROTOCOL_ERROR);
                     return false;
@@ -206,16 +206,16 @@ namespace Microsoft.AspNetCore.Server.Kestrel.Core.Internal.Http2
             // - That said, we shouldn't allow arbitrary values or use them to populate Request.Scheme, right?
             // - For now we'll restrict it to http/s and require it match the transport.
             // - We'll need to find some concrete scenarios to warrant unblocking this.
-            if (!string.Equals(RequestHeaders[HeaderNames.Scheme], Scheme, StringComparison.OrdinalIgnoreCase))
+            if (!string.Equals(HttpRequestHeaders.HeaderScheme, Scheme, StringComparison.OrdinalIgnoreCase))
             {
                 ResetAndAbort(new ConnectionAbortedException(
-                    CoreStrings.FormatHttp2StreamErrorSchemeMismatch(RequestHeaders[HeaderNames.Scheme], Scheme)), Http2ErrorCode.PROTOCOL_ERROR);
+                    CoreStrings.FormatHttp2StreamErrorSchemeMismatch(HttpRequestHeaders.HeaderScheme, Scheme)), Http2ErrorCode.PROTOCOL_ERROR);
                 return false;
             }
 
             // :path (and query) - Required
             // Must start with / except may be * for OPTIONS
-            var path = RequestHeaders[HeaderNames.Path].ToString();
+            var path = HttpRequestHeaders.HeaderPath.ToString();
             RawTarget = path;
 
             // OPTIONS - https://tools.ietf.org/html/rfc7540#section-8.1.2.3
@@ -252,7 +252,7 @@ namespace Microsoft.AspNetCore.Server.Kestrel.Core.Internal.Http2
         private bool TryValidateMethod()
         {
             // :method
-            _methodText = RequestHeaders[HeaderNames.Method].ToString();
+            _methodText = HttpRequestHeaders.HeaderMethod.ToString();
             Method = HttpUtilities.GetKnownMethod(_methodText);
 
             if (Method == HttpMethod.None)
@@ -278,7 +278,7 @@ namespace Microsoft.AspNetCore.Server.Kestrel.Core.Internal.Http2
             // :authority (optional)
             // Prefer this over Host
 
-            var authority = RequestHeaders[HeaderNames.Authority];
+            var authority = HttpRequestHeaders.HeaderAuthority;
             var host = HttpRequestHeaders.HeaderHost;
             if (!StringValues.IsNullOrEmpty(authority))
             {

src/Servers/Kestrel/shared/KnownHeaders.cs

@@ -19,6 +19,10 @@ namespace CodeGenerator
         {
             var requestPrimaryHeaders = new[]
             {
+                ":authority",
+                ":method",
+                ":path",
+                ":scheme",
                 "Accept",
                 "Connection",
                 "Host",
@@ -72,6 +76,10 @@ namespace CodeGenerator
             };
             RequestHeaders = commonHeaders.Concat(new[]
             {
+                ":authority",
+                ":method",
+                ":path",
+                ":scheme",
                 "Accept",
                 "Accept-Charset",
                 "Accept-Encoding",
@@ -247,7 +255,7 @@ namespace CodeGenerator
         {
             public string Name { get; set; }
             public int Index { get; set; }
-            public string Identifier => Name.Replace("-", "");
+            public string Identifier => ResolveIdentifier(Name);
 
             public byte[] Bytes => Encoding.ASCII.GetBytes($"\r\n{Name}: ");
             public int BytesOffset { get; set; }
@@ -264,6 +272,21 @@ namespace CodeGenerator
             public string SetBit() => $"_bits |= {"0x" + (1L << Index).ToString("x")}L";
             public string ClearBit() => $"_bits &= ~{"0x" + (1L << Index).ToString("x")}L";
 
+            private string ResolveIdentifier(string name)
+            {
+                var identifer = name.Replace("-", "");
+
+                // Pseudo headers start with a colon. A colon isn't valid in C# names so
+                // remove it and pascal case the header name. e.g. :path -> Path, :scheme -> Scheme.
+                // This identifier will match the names in HeadersNames.cs
+                if (identifer.StartsWith(':'))
+                {
+                    identifer = char.ToUpper(identifer[1]) + identifer.Substring(2);
+                }
+
+                return identifer;
+            }
+
             private void GetMaskAndComp(string name, int offset, int count, out ulong mask, out ulong comp)
             {
                 mask = 0;