When `webhook.PROXY_URL` has been set, the old code will check if the
proxy host is in `ALLOWED_HOST_LIST` or reject requests through the
proxy. It requires users to add the proxy host to `ALLOWED_HOST_LIST`.
However, it actually allows all requests to any port on the host, when
the proxy host is probably an internal address.
But things may be even worse. `ALLOWED_HOST_LIST` doesn't really work
when requests are sent to the allowed proxy, and the proxy could forward
them to any hosts.
This PR fixes it by:
- If the proxy has been set, always allow connectioins to the host and
port.
- Check `ALLOWED_HOST_LIST` before forwarding.
Change all license headers to comply with REUSE specification.
Fix #16132
Co-authored-by: flynnnnnnnnnn <flynnnnnnnnnn@github>
Co-authored-by: John Olheiser <john.olheiser@gmail.com>
Use hostmacher to replace matchlist.
And we introduce a better DialContext to do a full host/IP check, otherwise the attackers can still bypass the allow/block list by a 302 redirection.
