foxyproxy/browser-extension

QUIC (HTTP/3) connections do not work when using socks5 proxies

vukitoso opened this issue · 8 comments

vukitoso commented

Hello.

Thank you very much for the FoxyProxy extension, a very useful extension, I use it all the time.

Firefox 121.0.1
FoxyProxy 8.9

When using socks5 proxies, QUIC (HTTP/3) connections do not work, only HTTP2.
I check here https://quic.nginx.org/quic.html

erosman commented

In Chrome, QUIC (HTTP/3) is a separate scheme than HTTP/HTTPS/SOCKS4/SOCKS5.

At the moment, proxy.ProxyInfo does not appear to support QUIC (HTTP/3).

I am going to have a chat with Mozilla engineers about it and get back to you.

Ref: ProxyChannelFilter.sys.mjs

  • 👍1
vukitoso commented

Strange. QUIC is just an add-on over UDP, just like HTTP is over TCP.
And Socks5 supports TCP and UDP. In theory it should work.

erosman commented

It appears that HTTP/3 proxy is disabled in Firefox at the moment.

ref: HttpBaseChannel.cpp

PS. QUIC proxy is supported by Chrome and is enabled in FoxyProxy 8.10

  • ❤️1
vukitoso commented

It appears that HTTP/3 proxy is disabled in Firefox at the moment.

Thanks a lot.
Did you find this yourself from the source code or did you talk to the Firefox developers?

erosman commented

I was told by the Firefox engineers.
I am following up with them to see if there are plans to add support.

erosman commented

Bug 1882018
This is because our SOCKS proxy layer does not support UDP traffic.

See also:
Bug 1808692: SOCKS implementation does not support UDP
Bug 1882071: Support QUIC (HTTP/3) scheme in proxy