Why would a NodeJS HTTP/2 proxy server RST_STREAM a client HEADER frame containing CONNECT nghttp2:443?

[hoolam]

Node.js Version

v22.14.0

NPM Version

v10.9.2

Operating System

Linux hp 6.11.0-19-generic #19~24.04.1-Ubuntu SMP PREEMPT_DYNAMIC Mon Feb 17 11:51:52 UTC 2 x86_64 x86_64 x86_64 GNU/Linux

Subsystem

http2

Description

Please help with the following problem I am experiencing, which is that a NodeJS proxy server is rejecting a CONNECT method from a client, with the error message "Invalid HTTP header field was received: frame type: 1, stream: 1, name: [:authority], value: [nghttp2.org:443]", but as far as I can tell, the :authority header is ok.

1. A HTTP2 client connects to a HTTP2 proxy server using h2c. It sends the following:
   a) A preface (24-byte octets "PRI * HTTP/2.0\r\n\r\nSM\r\n\r\n")
   b) A SETTINGS frame - Max concurrent streams : 100
   c) A HEADERS frame for stream 1 - :method: CONNECT and :authority: nghttp2.org:443

2. The server responds with its own SETTINGS - default settings

3. The client ACK's the server's SETTINGS

4. The server ACK's the client's SETTINGS and RST_STREAM the client's stream 1 (see 1(c) above).

5. According to the debugging messages produced by the server by setting NODE_DEBUG_NATIVE=http2, the reason for the server to RST_STREAM is as follows, but as far as I can tell, there's nothing wrong with the :authority header.

'Invalid HTTP header field was received: frame type: 1, stream: 1, name: [:authority], value: [nghttp2.org:443]'

6. I tried to attach herewith the following 3 files, but only succeeded with (a), and both (b) and (c) failed to upload.
   a) The debugging messages produced by the server
   b) A PDF showing the exchanges between the client and the server captured by Wireshark
   c) A PDF showing only the HTTP2 exchanges between the client and the server captured by Wireshark

proxy_debug_msgs.log

Minimal Reproduction

No response

Output

'Invalid HTTP header field was received: frame type: 1, stream: 1, name: [:authority], value: [nghttp2.org:443]'

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