gmid

gmid is a full-featured Gemini server written with security in mind. It can serve static files, has optional FastCGI and proxying support, and a rich configuration syntax.

A few helper programs are shipped as part of gmid:

• gg is a simple command-line Gemini client.

• gemexp is a stripped-down config-less version of gmid to quickly serve a directory from the command line.

• titan is a command-line titan client.

Internationalisation (IRIs, IDN, UNICODE)

Even thought the current Gemini specification doesn't mention anything in this regard, I think it's important to make as easy as possible to use non-ASCII characters in domain names and URL paths.

For starters, gmid has full support for IRIs (RFC3987 — Internationalized Resource Identifiers). IRIs are a superset of URIs that allow UNICODE characters, so there aren't incompatibilities with URI-only clients.

There is full support also for IDNs (Internationalized Domain Names). There's no need to fiddle with punycode, or even know what it is: the hostname in the configuration file can (and must be) in the decoded form (e.g. naïve and not xn--nave-6pa), gmid will do the rest.

The only missing piece is UNICODE normalisation of the IRI path: gmid doesn't do that (yet).

Configuration

gmid has a rich configuration file, heavily inspired by OpenBSD' httpd(8), with every detail carefully documented in the manpage. Here's a minimal example of a config file:

# /etc/gmid.conf
server "example.com" {
	listen on * port 1965
	cert "/path/to/cert.pem"
	key  "/path/to/key.pem"
	root "/var/gemini/example.com"
}

and a slightly more complex one

# /etc/gmid.conf
cert_root = "/path/to/keys"

server "example.com" {
	listen on * port 1965

	alias "foobar.com"

	cert $cert_root "/example.com.crt"
	key  $cert_root "/example.com.pem"
	root "/var/gemini/example.com"

	# lang for text/gemini files
	lang "en"

	# only for locations that matches /files/*
	location "/files/*" {
		# generate directory listings
		auto index on
	}

	location "/repo/*" {
		# change the index file name
		index "README.gmi"
		lang "it"
	}
}

Building

gmid depends on libevent2, LibreSSL or OpenSSL, and yacc or GNU bison.

The build is as simple as

$ ./configure
$ make

If the configure scripts fails to pick up something, please open an issue or notify me via email.

To install execute:

# make install

Testing

Execute

$ make regress

to start the suite. Keep in mind that the regression tests needs to create a few file inside the regress directory and bind the 10965 and 10966 ports.

Contributing

Any form of contribution is welcome, not only patches or bug reports. If you have a sample configuration for some specific use-case, a script or anything that could be useful to others, consider adding it to the contrib directory.

Architecture/Security considerations

gmid has a privsep design, where the operations done by the daemon are split into multiple processes:

• main: the main process is the only one that keeps the original privileges. It opens the TLS certificates on the behalf of the server and crypto processes, reloads the configuration upon SIGHUP and re-opens the log files upon SIGUSR1.

• logger: handles the logging with syslog and/or local files.

• server: listens for connections and handles the requests. It also speaks FastCGI and do the proxying.

• crypto: holds the TLS private keys to avoid a compromised server process to disclose them.