6 ms·

In theory request smuggling is not possible with end-to-end HTTP/2. It's only possible if there is a downgrade to HTTP/1 at some point.

• SahAssar 2y ago
  A h2 proxy usually wouldn't proxy through the http2 connection, it would instead accept h2, load-balance each request to a backend over a h2 (or h1) connection. The difference is that you have a h2 connection to the proxy, but everything past that point is up to the proxies routing. End-to-end h2 would be more like a websocket (which runs over HTTP CONNECT) where the proxy is just proxying a socket (often with TLS unwrapping).
  • nitely 2y ago
    > A h2 proxy usually wouldn't proxy through the http2 connection, it would instead accept h2, load-balance each request to a backend over a h2 (or h1) connection. Each connection need to keep state of all processed requests (the HPACK dynamic headers table), so all request for a given connection need to be proxied through the same connection. Not sure I got what you meant, though. Apart from that, I think the second sentence of my comment makes clear there is no smuggling as long as the connection before/past proxy is http2, and it's not downgraded to http1. That's all that I meant.