Describe the feature request

I saw both in the README.md, the frpc.toml sample, and the golib code itself (link1, link2) that we only support: socks5, http and ntlm:

var supportedDialProxyTypes = []string{"socks5", "http", "ntlm"}

But what if I have an https proxy, e.g. https://my.proxy.server.com:8888 rather than http://my.proxy.server.com:8888?
Was wondering why isn't it supported and what would it take to support an HTTPS proxy?
For the sake of clarity, I don't care about MitM (man-in-the-middle) proxies, I'm talking about a scenario where the frpc (frp client) connects to frps (frp server) through a proxy with an https:// protocol scheme.

I'm guessing that from the user's perspective we'd need to (1) pass a custom CA (as most likely it's a local proxy with a private PKI), (2) add TLS handshake support to golib and the rest should be the same, i.e. pass a CONNECT to frps over that established connection.

I know that it might not make a lot of sense to everyone to actually use an https proxy, but nevertheless wondering what's the dev effort / design considerations that were led to not supporting it.

Thanks!
Ofir

Describe alternatives you've considered

No response

Affected area

• Docs
• Installation
• Performance and Scalability
• Security
• User Experience
• Test and Release
• Developer Infrastructure
• Client Plugin
• Server Plugin
• Extensions
• Others