Implement secure gopher protocol.

[parazyd]

This commit introduces a "gophers" handler inside the gopher protocol if
USE_SSL is defined. This protocol is no different than the usual gopher
prococol, with the added TLS encapsulation upon connecting. The protocol
has been adopted in the gopher community, and many people have enabled
TLS in their gopher daemons like geomyidae(8), and clients, like clic(1)
and hurl(1).

I have not implemented test units for this protocol because my knowledge
of Perl is sub-par. However, for someone more knowledgeable it might be
fairly trivial, because the same test that tests the plain gopher
protocol can be used for "gophers" just by adding a TLS listener.

Signed-off-by: parazyd parazyd@dyne.org

[parazyd]

As for manual testing, it can be tested with servers that support TLS:

curl gophers://parazyd.org

[cvengler]

Sorry, I disagree. So far there is no specification for it.
In March this year I brought up a discussion at the Gopher-ML about a specification (https://lists.debian.org/gopher-project/2020/03/msg00005.html)
As long as there isn't anything to agree on this shouldn't be merged in my opinion.

[cvengler]

Ping @sebdeckers, maybe interesting for you?

[sebdeckers]

TIMTOWTDI 🤷🏼‍♂️ Been a few months since I looked into that discussion. Has anyone begun the IETF legwork to discuss/propose a Gopher with TLS spec? I've seen a bunch of approaches with pros/cons.

[cvengler]

I would prefer to not do the discussion here, but as far as I know there hasn't been any progress made mostly due to backwards compatibility issues

[parazyd]

I would prefer to not do the discussion here, but as far as I know there hasn't been any progress made mostly due to backwards compatibility issues

There are no compatibility issues with my patch and proposal. Daemons like geomyidae already implement this specific proposal.

[bagder]

Sorry, I disagree. So far there is no specification for it.
In March this year I brought up a discussion at the Gopher-ML about a specification (https://lists.debian.org/gopher-project/2020/03/msg00005.html)
As long as there isn't anything to agree on this shouldn't be merged in my opinion.

I disagree. For me, even without a URL spec - if there is an adopted URL syntax already with both consumers and providers, that fact puts the code and suggestion in different angle.

@parazyd do you perhaps even already have this TLS version of the URI format documented somewhere for reference?

[parazyd]

@bagder Mostly documented in code. Here are a few links:

• https://lists.debian.org/gopher-project/2020/06/msg00001.html
• https://git.codemadness.org/hurl/commit/9546c0f17665658befbc25876245acaa9db4b08f.html
• http://r-36.net/scm/geomyidae/commit/07240d76fd8e1d0a67c49bf7e123bb508613e691.html
• http://r-36.net/scm/geomyidae/commit/89d4f0d0cf90543362a036133e88cb9fe21513d4.html

[bagder]

I volunteer to extend the test suite for gophers.

[parazyd]

@bagder If it makes sense, could you push to this branch and then we can make it a more complete merge request?

[bagder]

Yes, once I have something to show!

[bagder]

One commit that adds support for 'gophers' to the test suite. The second one provides an initial test case: that's test 1200 just updated to do gophers instead.

[bagder]

related: you should consider registering the gophers URI scheme at https://www.iana.org/assignments/uri-schemes/uri-schemes.xhtml

[bagder]

coming back to this: now we have a docs/URL-SYNTAX.md document that should be extended to also mention this scheme.

Anything else that needs to be done before we merge?

[parazyd]

I think we're all set if that is added :)

[bagder]

Thanks!