1 .\" Copyright (c) 2021 Omar Polo <op@omarpolo.com>
3 .\" Permission to use, copy, modify, and distribute this software for any
4 .\" purpose with or without fee is hereby granted, provided that the above
5 .\" copyright notice and this permission notice appear in all copies.
7 .\" THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
8 .\" WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
9 .\" MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
10 .\" ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
11 .\" WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
12 .\" ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
13 .\" OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
14 .Dd $Mdocdate: January 30 2021$
19 .Nd simple and secure Gemini server
25 .Op Fl D Ar macro Ns = Ns Ar value
39 is a simple and minimal gemini server that can serve static files,
40 execute CGI scripts and talk to FastCGI applications.
41 It can run without a configuration file with a limited set of features
45 rereads the configuration file when it receives
48 The options are as follows:
51 Specify the configuration file.
52 .It Fl D Ar macro Ns = Ns Ar value
58 Overrides the definition of
60 in the config file if present.
62 Stays and logs on the foreground.
64 Check that the configuration is valid, but don't start the server.
68 pid to the given path.
71 If no configuration file is given,
73 will look for the following options
77 .It Fl d Pa certs-path
78 Directory where certificates for the config-less mode are stored.
80 .Pa $XDG_DATA_HOME/gmid ,
82 .Pa ~/.local/share/gmid .
84 The hostname, by default
86 Certificates for the given
88 are searched inside the
90 directory given with the
96 .Pa hostname.key.pem .
97 If a certificate or key don't exists for a given hostname they
98 will be automatically generated.
100 Print the usage and exit.
102 The port to listen on, by default 1965.
103 .It Fl V , Fl -version
104 Print the version and exit.
109 options increase the verbosity.
111 Enable execution of CGI scripts.
112 See the description of the
114 option in the section
119 Cannot be provided more than once.
121 The root directory to serve.
122 By default the current working directory is assumed.
124 .Sh CONFIGURATION FILE
125 The configuration file is divided into three sections:
128 User-defined variables may be defined and used later, simplifying the
130 .It Sy Global Options
134 Virtual hosts definition.
137 Within the sections, empty lines are ignored and comments can be put
138 anywhere in the file using a hash mark
140 and extend to the end of the current line.
141 A boolean is either the symbol
145 A string is a sequence of characters wrapped in double quotes,
148 Strict ordering of the sections is not enforced, so that is possible
149 to mix macros, options and
152 However, defining all the
154 blocks after the macros and the global options is recommended.
156 Macros can be defined that will later be expanded in context.
157 Macro names must start with a letter, digit or underscore and may
158 contain any of those characters.
159 Macro names may not be reserved words.
160 Macros are expanded inside the quotes too.
163 .Bd -literal -offset indent
168 root "$dir/foo" # -> /var/gemini/foo
169 cert "$cert/foo.crt" # -> /etc/keys/foo.crt
170 key "$cert/foo.pem" # -> /etc/keys/foo.pem
175 .It Ic chroot Pa path
177 the process to the given
179 The daemon has to be run with root privileges and thus the option
181 needs to be provided, so privileges can be dropped.
184 will enter the chroot after loading the TLS keys, but before opening
185 the virtual host root directories.
186 It's recommended to keep the TLS keys outside the chroot.
191 Enable or disable IPv6 support.
193 .It Ic mime Ar mime-type Ar file-extension
194 Add a mapping for the given
198 Both argument are strings.
199 .It Ic port Ar portno
200 The port to listen on.
202 .It Ic prefork Ar number
203 Run the specified number of server processes.
204 This increases the performance and prevents delays when connecting to
207 runs 3 server processes by default, when not in config-less mode.
208 The maximum number allowed is 16.
209 .It Ic protocols Ar string
210 Specify the TLS protocols to enable.
212 .Xr tls_config_parse_protocols 3
213 for the valid protocol string values.
214 By default, both TLSv1.3 and TLSv1.2 are enabled.
217 to enable only TLSv1.3.
218 .It Ic user Ar string
219 Run the daemon as the given user.
222 Every virtual host is defined by a
226 .It Ic server Ar hostname Brq ...
227 Match the server name using shell globbing rules.
228 This can be an explicit name,
229 .Ar www.example.com ,
230 or a name including a wildcards,
234 Followed by a block of options that is enclosed in curly brackets:
237 Specify an additional alias
240 .It Ic auto Ic index Ar bool
241 If no index file is found, automatically generate a directory listing.
242 It's disabled by default.
243 .It Ic block Op Ic return Ar code Op Ar meta
244 Send a reply and close the connection;
250 .Dq temporary failure
254 is in the 3x range, then
259 the following special sequences are replaced:
260 .Bl -tag -width Ds -compact
262 is replaced with a single
265 is replaced with the request path.
267 is replaced with the query string of the request.
269 is replaced with the server port.
271 is replaced with the server name.
274 Path to the certificate to use for this server.
277 should contain a PEM encoded certificate.
278 This option is mandatory.
280 Execute CGI scripts that matches
282 using shell globbing rules.
283 .It Ic default type Ar string
284 Set the default media type that is used if the media type for a
285 specified extension is not found.
286 If not specified, the
289 .Dq application/octet-stream .
290 .It Ic entrypoint Pa path
291 Handle all the requests for the current virtual host using the
294 .It Ic env Ar name Ar value
295 Set the environment variable
299 when executing CGI scripts.
300 Can be provided more than once.
301 .\" don't document the "spawn <prog>" form because it probably won't
303 .It Ic fastcgi Oo Ic tcp Oc Pa socket Oo Ar port Oc
304 Enable FastCGI instead of serving files.
307 can either be a UNIX domain socket or a TCP socket.
308 If the FastCGI application is listening on a UNIX domain socket,
310 is a local path name within the
316 keyword must be provided and
318 is interpreted as a hostname or an IP address.
320 can be either a port number or the name of a service enclosed in
322 If it's not specified defaults to 9000.
323 .It Ic index Ar string
324 Set the directory index file.
325 If not specified, it defaults to
328 Specify the private key to use for this server.
331 should contain a PEM encoded private key.
332 This option is mandatory.
333 .It Ic lang Ar string
334 Specify the language tag for the text/gemini content served.
337 parameter will be added in the response.
338 .It Ic location Pa path Brq ...
339 Specify server configuration rules for a specific location.
342 argument will be matched against the request path with shell globbing
344 In case of multiple location statements in the same context, the first
345 matching location will be put into effect and the later ones ignored.
346 Therefore is advisable to match for more specific paths first and for
347 generic ones later on.
350 section may include most of the server configuration rules
352 .Ic alias , Ic cert , Ic env , Ic key , Ic location ,
353 .Ic entrypoint No and Ic cgi .
355 Enable or disable the logging for the current server or location block.
356 .It Ic param Ar name Ar value
362 .It Ic root Pa directory
363 Specify the root directory for this server.
364 It's relative to the chroot, if enabled.
365 .It Ic require Ic client Ic ca Pa path
366 Allow requests only from clients that provide a certificate signed by
367 the CA certificate in
369 It needs to be a PEM-encoded certificate and it's not relative to the
371 .It Ic strip Ar number
374 components from the beginning of the path before doing a lookup in the
376 It's also considered for the
378 parameter in the scope of a
382 When a request for an executable file matches the
384 rule, that file will be execute and its output fed to the client.
386 The CGI scripts are executed in the directory they reside and inherit
389 with these additional variables set:
391 .It Ev GATEWAY_INTERFACE
393 .It Ev GEMINI_DOCUMENT_ROOT
394 The root directory of the virtual host.
395 .It Ev GEMINI_SCRIPT_FILENAME
396 Full path to the CGI script being executed.
398 The full IRI of the request.
399 .It Ev GEMINI_URL_PATH
400 The path of the request.
402 The portion of the requested path that is derived from the the IRI
403 path hierarchy following the part that identifies the script itself.
405 .It Ev PATH_TRANSLATED
406 Present if and only if
409 It represent the translation of the
412 builds this by appending the
414 to the virtual host directory root.
416 The decoded query string.
417 .It Ev REMOTE_ADDR , Ev REMOTE_HOST
418 Textual representation of the client IP.
419 .It Ev REQUEST_METHOD
420 This is present only for RFC3875 (CGI) compliance.
421 It's always set to the empty string.
425 that identifies the current CGI script.
427 The name of the server
429 The port the server is listening on.
430 .It Ev SERVER_PROTOCOL
432 .It Ev SERVER_SOFTWARE
433 The name and version of the server, i.e.
436 The string "Certificate" if the client used a certificate, otherwise
439 The subject of the client certificate if provided, otherwise unset.
440 .It Ev TLS_CLIENT_ISSUER
441 The is the issuer of the client certificate if provided, otherwise
443 .It Ev TLS_CLIENT_HASH
444 The hash of the client certificate if provided, otherwise unset.
448 The TLS version negotiated with the peer.
450 The cipher suite negotiated with the peer.
451 .It Ev TLS_CIPHER_STRENGTH
452 The strength in bits for the symmetric cipher that is being used with
454 .It Ev TLS_CLIENT_NOT_AFTER
455 The time corresponding to the end of the validity period of the peer
456 certificate in the ISO 8601 format
457 .Pq e.g. Dq 2021-02-07T20:17:41Z .
458 .It Ev TLS_CLIENT_NOT_BEFORE
459 The time corresponding to the start of the validity period of the peer
460 certificate in the ISO 8601 format.
464 optionally supports FastCGI.
467 rule must be present in a server or location block.
468 Then, all requests matching that server or location will be handled
469 via the specified FastCGI backend.
471 By default the following variables
473 are sent, and carry the same semantics as with CGI.
474 More parameters can be added with the
511 TLS_CLIENT_NOT_BEFORE
516 To auto-detect the MIME type of the response
518 looks at the file extension and consults its internal table.
519 By default the following mappings are loaded, but they can be
520 overridden or extended using the
522 configuration option.
523 If no MIME is found, the value of
527 will be used, which is
528 .Dq application/octet-stream
531 .Bl -tag -offset indent -width 14m -compact
558 Serve the current directory
559 .Bd -literal -offset indent
563 To serve the directory
565 and enable CGI scripts inside
568 .Bd -literal -offset indent
570 $ cat <<EOF > docs/cgi/hello
572 printf "20 text/plain\\r\\n"
575 $ chmod +x docs/cgi/hello
576 $ gmid -x '/cgi/*' docs
579 The following is an example of a possible configuration for a site
580 that enables only TLSv1.3, adds a mime type for the file extension
581 "rtf" and defines two virtual host:
582 .Bd -literal -offset indent
583 ipv6 on # enable ipv6
587 mime "application/rtf" "rtf"
589 server "example.com" {
590 cert "/path/to/cert.pem"
591 key "/path/to/key.pem"
592 root "/var/gemini/example.com"
595 server "it.example.com" {
596 cert "/path/to/cert.pem"
597 key "/path/to/key.pem"
598 root "/var/gemini/it.example.com"
604 Yet another example, showing how to enable a
609 .Bd -literal -offset indent
613 server "example.com" {
614 cert "/path/to/cert.pem"
615 key "/path/to/key.pem"
616 root "/example.com" # in the /var/gemini chroot
618 location "/static/*" {
627 .Dq Flexible and Economical
628 UTF-8 decoder written by
629 .An Bjoern Hoehrmann .
634 program was written by
635 .An Omar Polo Aq Mt op@omarpolo.com .
639 The root directories of all virtual hosts are opened during the daemon
640 startup; this means that if a root directory gets deleted and then
643 won't be able to serve files inside that directory until a restart.
644 This restriction applies only to the root directories and not their content.
646 a %2F sequence is indistinguishable from a literal slash: this is not
649 a %00 sequence is treated as invalid character and thus rejected.
