add support for gemini protocol (port 1965)

[emceeaich]

I'm part of a group of hobbyists working with a protocol, gemini, designed to sit between gopher and http.

See: https://portal.mozz.us/gemini/gemini.circumlunar.space/ (portal.mozz.us is a gemini to http proxy)

The protocol uses port 1965 and I'd like to be able to create pagekites on that port.

At the moment, I get error messages that tunneling that port is not allowed, would it be possible to support that?

[BjarniRunar]

Hello! Thanks for suggesting this.

I have one important question: Does the protcol's client announce the name of the server it is connecting to, when it connects?

In TLS this is done using an SNI header, in HTTP this is done using the Host: header. XMPP also has an equivalent. Protocols such as SSH, IMAP and POP3 however do not, which is why they cannot be natively supported by PageKite.

Which category does the Gemini protocol fall in?

(The separate issue, whether pagekite.net listens on port 1965 or not, depends on this one - there is no point listening on that port if the protocol itself cannot work.)

[emceeaich]

Let me ask the folks working on the spec! Thanks.

…

On Sun, May 31, 2020, at 11:59, Bjarni Rúnar Einarsson wrote: Hello! Thanks for suggesting this. I have one important question: Does the protcol's client announce the name of the server it is connecting to, when it connects? In TLS this is done using an SNI header, in HTTP this is done using the Host: header. XMPP also has an equivalent. Protocols such as SSH, IMAP and POP3 however do not, which is why they cannot be natively supported by PageKite. Which category does the Gemini protocol fall in? (The separate issue, whether pagekite.net listens on port 1965 or not, depends on this one - there is no point listening on that port if the protocol itself cannot work.) — You are receiving this because you authored the thread. Reply to this email directly, view it on GitHub <#85 (comment)>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/ACNND7B45MR6NS6KD3LRH23RUKSHXANCNFSM4NDSCYFA>.

[emceeaich]

To answer your question, yes. Gemini uses an SNI header.

https://portal.mozz.us/gemini/gemini.circumlunar.space/docs/spec-spec.txt

4 TLS

Use of TLS for Gemini transactions is mandatory.

Use of the Server Name Indication (SNI) extension to TLS is also
mandatory, to facilitate name-based virtual hosting.

4.1 Version requirements

Servers MUST use TLS version 1.2 or higher and SHOULD use TLS version
1.3 or higher.  TLS 1.2 is reluctantly permitted for now to avoid
drastically reducing the range of available implementation libraries.
Hopefully TLS 1.3 or higher can be specced in the near future.
Clients who wish to be "ahead of the curve MAY refuse to connect to
servers using TLS version 1.2 or lower.