services: httpd: Allow using it with PHP.
[jackhill/guix/guix.git] / gnu / services / ssh.scm
1 ;;; GNU Guix --- Functional package management for GNU
2 ;;; Copyright © 2014, 2015, 2016, 2017, 2018 Ludovic Courtès <ludo@gnu.org>
3 ;;; Copyright © 2016 David Craven <david@craven.ch>
4 ;;; Copyright © 2016 Julien Lepiller <julien@lepiller.eu>
5 ;;; Copyright © 2017 Clément Lassieur <clement@lassieur.org>
6 ;;;
7 ;;; This file is part of GNU Guix.
8 ;;;
9 ;;; GNU Guix is free software; you can redistribute it and/or modify it
10 ;;; under the terms of the GNU General Public License as published by
11 ;;; the Free Software Foundation; either version 3 of the License, or (at
12 ;;; your option) any later version.
13 ;;;
14 ;;; GNU Guix is distributed in the hope that it will be useful, but
15 ;;; WITHOUT ANY WARRANTY; without even the implied warranty of
16 ;;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
17 ;;; GNU General Public License for more details.
18 ;;;
19 ;;; You should have received a copy of the GNU General Public License
20 ;;; along with GNU Guix. If not, see <http://www.gnu.org/licenses/>.
21
22 (define-module (gnu services ssh)
23 #:use-module (gnu packages ssh)
24 #:use-module (gnu packages admin)
25 #:use-module (gnu services)
26 #:use-module (gnu services shepherd)
27 #:use-module (gnu system pam)
28 #:use-module (gnu system shadow)
29 #:use-module (guix gexp)
30 #:use-module (guix records)
31 #:use-module (guix modules)
32 #:use-module (srfi srfi-1)
33 #:use-module (srfi srfi-26)
34 #:use-module (ice-9 match)
35 #:export (lsh-configuration
36 lsh-configuration?
37 lsh-service
38 lsh-service-type
39
40 openssh-configuration
41 openssh-configuration?
42 openssh-service-type
43
44 dropbear-configuration
45 dropbear-configuration?
46 dropbear-service-type
47 dropbear-service))
48
49 ;;; Commentary:
50 ;;;
51 ;;; This module implements secure shell (SSH) services.
52 ;;;
53 ;;; Code:
54
55 (define-record-type* <lsh-configuration>
56 lsh-configuration make-lsh-configuration
57 lsh-configuration?
58 (lsh lsh-configuration-lsh
59 (default lsh))
60 (daemonic? lsh-configuration-daemonic?)
61 (host-key lsh-configuration-host-key)
62 (interfaces lsh-configuration-interfaces)
63 (port-number lsh-configuration-port-number)
64 (allow-empty-passwords? lsh-configuration-allow-empty-passwords?)
65 (root-login? lsh-configuration-root-login?)
66 (syslog-output? lsh-configuration-syslog-output?)
67 (pid-file? lsh-configuration-pid-file?)
68 (pid-file lsh-configuration-pid-file)
69 (x11-forwarding? lsh-configuration-x11-forwarding?)
70 (tcp/ip-forwarding? lsh-configuration-tcp/ip-forwarding?)
71 (password-authentication? lsh-configuration-password-authentication?)
72 (public-key-authentication? lsh-configuration-public-key-authentication?)
73 (initialize? lsh-configuration-initialize?))
74
75 (define %yarrow-seed
76 "/var/spool/lsh/yarrow-seed-file")
77
78 (define (lsh-initialization lsh host-key)
79 "Return the gexp to initialize the LSH service for HOST-KEY."
80 #~(begin
81 (unless (file-exists? #$%yarrow-seed)
82 (system* (string-append #$lsh "/bin/lsh-make-seed")
83 "--sloppy" "-o" #$%yarrow-seed))
84
85 (unless (file-exists? #$host-key)
86 (mkdir-p (dirname #$host-key))
87 (format #t "creating SSH host key '~a'...~%" #$host-key)
88
89 ;; FIXME: We're just doing a simple pipeline, but 'system' cannot be
90 ;; used yet because /bin/sh might be dangling; factorize this somehow.
91 (let* ((in+out (pipe))
92 (keygen (primitive-fork)))
93 (case keygen
94 ((0)
95 (close-port (car in+out))
96 (close-fdes 1)
97 (dup2 (fileno (cdr in+out)) 1)
98 (execl (string-append #$lsh "/bin/lsh-keygen")
99 "lsh-keygen" "--server"))
100 (else
101 (let ((write-key (primitive-fork)))
102 (case write-key
103 ((0)
104 (close-port (cdr in+out))
105 (close-fdes 0)
106 (dup2 (fileno (car in+out)) 0)
107 (execl (string-append #$lsh "/bin/lsh-writekey")
108 "lsh-writekey" "--server" "-o" #$host-key))
109 (else
110 (close-port (car in+out))
111 (close-port (cdr in+out))
112 (waitpid keygen)
113 (waitpid write-key))))))))))
114
115 (define (lsh-activation config)
116 "Return the activation gexp for CONFIG."
117 #~(begin
118 (use-modules (guix build utils))
119 (mkdir-p "/var/spool/lsh")
120 #$(if (lsh-configuration-initialize? config)
121 (lsh-initialization (lsh-configuration-lsh config)
122 (lsh-configuration-host-key config))
123 #t)))
124
125 (define (lsh-shepherd-service config)
126 "Return a <shepherd-service> for lsh with CONFIG."
127 (define lsh (lsh-configuration-lsh config))
128 (define pid-file (lsh-configuration-pid-file config))
129 (define pid-file? (lsh-configuration-pid-file? config))
130 (define daemonic? (lsh-configuration-daemonic? config))
131 (define interfaces (lsh-configuration-interfaces config))
132
133 (define lsh-command
134 (append
135 (cons (file-append lsh "/sbin/lshd")
136 (if daemonic?
137 (let ((syslog (if (lsh-configuration-syslog-output? config)
138 '()
139 (list "--no-syslog"))))
140 (cons "--daemonic"
141 (if pid-file?
142 (cons #~(string-append "--pid-file=" #$pid-file)
143 syslog)
144 (cons "--no-pid-file" syslog))))
145 (if pid-file?
146 (list #~(string-append "--pid-file=" #$pid-file))
147 '())))
148 (cons* #~(string-append "--host-key="
149 #$(lsh-configuration-host-key config))
150 #~(string-append "--password-helper=" #$lsh "/sbin/lsh-pam-checkpw")
151 #~(string-append "--subsystems=sftp=" #$lsh "/sbin/sftp-server")
152 "-p" (number->string (lsh-configuration-port-number config))
153 (if (lsh-configuration-password-authentication? config)
154 "--password" "--no-password")
155 (if (lsh-configuration-public-key-authentication? config)
156 "--publickey" "--no-publickey")
157 (if (lsh-configuration-root-login? config)
158 "--root-login" "--no-root-login")
159 (if (lsh-configuration-x11-forwarding? config)
160 "--x11-forward" "--no-x11-forward")
161 (if (lsh-configuration-tcp/ip-forwarding? config)
162 "--tcpip-forward" "--no-tcpip-forward")
163 (if (null? interfaces)
164 '()
165 (map (cut string-append "--interface=" <>)
166 interfaces)))))
167
168 (define requires
169 (if (and daemonic? (lsh-configuration-syslog-output? config))
170 '(networking syslogd)
171 '(networking)))
172
173 (list (shepherd-service
174 (documentation "GNU lsh SSH server")
175 (provision '(ssh-daemon))
176 (requirement requires)
177 (start #~(make-forkexec-constructor (list #$@lsh-command)))
178 (stop #~(make-kill-destructor)))))
179
180 (define (lsh-pam-services config)
181 "Return a list of <pam-services> for lshd with CONFIG."
182 (list (unix-pam-service
183 "lshd"
184 #:allow-empty-passwords?
185 (lsh-configuration-allow-empty-passwords? config))))
186
187 (define lsh-service-type
188 (service-type (name 'lsh)
189 (description
190 "Run the GNU@tie{}lsh secure shell (SSH) daemon,
191 @command{lshd}.")
192 (extensions
193 (list (service-extension shepherd-root-service-type
194 lsh-shepherd-service)
195 (service-extension pam-root-service-type
196 lsh-pam-services)
197 (service-extension activation-service-type
198 lsh-activation)))))
199
200 (define* (lsh-service #:key
201 (lsh lsh)
202 (daemonic? #t)
203 (host-key "/etc/lsh/host-key")
204 (interfaces '())
205 (port-number 22)
206 (allow-empty-passwords? #f)
207 (root-login? #f)
208 (syslog-output? #t)
209 (pid-file? #f)
210 (pid-file "/var/run/lshd.pid")
211 (x11-forwarding? #t)
212 (tcp/ip-forwarding? #t)
213 (password-authentication? #t)
214 (public-key-authentication? #t)
215 (initialize? #t))
216 "Run the @command{lshd} program from @var{lsh} to listen on port @var{port-number}.
217 @var{host-key} must designate a file containing the host key, and readable
218 only by root.
219
220 When @var{daemonic?} is true, @command{lshd} will detach from the
221 controlling terminal and log its output to syslogd, unless one sets
222 @var{syslog-output?} to false. Obviously, it also makes lsh-service
223 depend on existence of syslogd service. When @var{pid-file?} is true,
224 @command{lshd} writes its PID to the file called @var{pid-file}.
225
226 When @var{initialize?} is true, automatically create the seed and host key
227 upon service activation if they do not exist yet. This may take long and
228 require interaction.
229
230 When @var{initialize?} is false, it is up to the user to initialize the
231 randomness generator (@pxref{lsh-make-seed,,, lsh, LSH Manual}), and to create
232 a key pair with the private key stored in file @var{host-key} (@pxref{lshd
233 basics,,, lsh, LSH Manual}).
234
235 When @var{interfaces} is empty, lshd listens for connections on all the
236 network interfaces; otherwise, @var{interfaces} must be a list of host names
237 or addresses.
238
239 @var{allow-empty-passwords?} specifies whether to accept log-ins with empty
240 passwords, and @var{root-login?} specifies whether to accept log-ins as
241 root.
242
243 The other options should be self-descriptive."
244 (service lsh-service-type
245 (lsh-configuration (lsh lsh) (daemonic? daemonic?)
246 (host-key host-key) (interfaces interfaces)
247 (port-number port-number)
248 (allow-empty-passwords? allow-empty-passwords?)
249 (root-login? root-login?)
250 (syslog-output? syslog-output?)
251 (pid-file? pid-file?) (pid-file pid-file)
252 (x11-forwarding? x11-forwarding?)
253 (tcp/ip-forwarding? tcp/ip-forwarding?)
254 (password-authentication?
255 password-authentication?)
256 (public-key-authentication?
257 public-key-authentication?)
258 (initialize? initialize?))))
259
260 \f
261 ;;;
262 ;;; OpenSSH.
263 ;;;
264
265 (define-record-type* <openssh-configuration>
266 openssh-configuration make-openssh-configuration
267 openssh-configuration?
268 ;; <package>
269 (openssh openssh-configuration-openssh
270 (default openssh))
271 ;; string
272 (pid-file openssh-configuration-pid-file
273 (default "/var/run/sshd.pid"))
274 ;; integer
275 (port-number openssh-configuration-port-number
276 (default 22))
277 ;; Boolean | 'without-password
278 (permit-root-login openssh-configuration-permit-root-login
279 (default #f))
280 ;; Boolean
281 (allow-empty-passwords? openssh-configuration-allow-empty-passwords?
282 (default #f))
283 ;; Boolean
284 (password-authentication? openssh-configuration-password-authentication?
285 (default #t))
286 ;; Boolean
287 (public-key-authentication? openssh-configuration-public-key-authentication?
288 (default #t))
289 ;; Boolean
290 (x11-forwarding? openssh-configuration-x11-forwarding?
291 (default #f))
292
293 ;; Boolean
294 (allow-agent-forwarding? openssh-configuration-allow-agent-forwarding?
295 (default #t))
296
297 ;; Boolean
298 (allow-tcp-forwarding? openssh-configuration-allow-tcp-forwarding?
299 (default #t))
300
301 ;; Boolean
302 (gateway-ports? openssh-configuration-gateway-ports?
303 (default #f))
304
305 ;; Boolean
306 (challenge-response-authentication? openssh-challenge-response-authentication?
307 (default #f))
308 ;; Boolean
309 (use-pam? openssh-configuration-use-pam?
310 (default #t))
311 ;; Boolean
312 (print-last-log? openssh-configuration-print-last-log?
313 (default #t))
314 ;; list of two-element lists
315 (subsystems openssh-configuration-subsystems
316 (default '(("sftp" "internal-sftp"))))
317
318 ;; list of strings
319 (accepted-environment openssh-configuration-accepted-environment
320 (default '()))
321
322 ;; symbol
323 (log-level openssh-configuration-log-level
324 (default 'info))
325
326 ;; list of user-name/file-like tuples
327 (authorized-keys openssh-authorized-keys
328 (default '()))
329
330 ;; Boolean
331 ;; XXX: This should really be handled in an orthogonal way, for instance as
332 ;; proposed in <https://bugs.gnu.org/27155>. Keep it internal/undocumented
333 ;; for now.
334 (%auto-start? openssh-auto-start?
335 (default #t)))
336
337 (define %openssh-accounts
338 (list (user-group (name "sshd") (system? #t))
339 (user-account
340 (name "sshd")
341 (group "sshd")
342 (system? #t)
343 (comment "sshd privilege separation user")
344 (home-directory "/var/run/sshd")
345 (shell #~(string-append #$shadow "/sbin/nologin")))))
346
347 (define (openssh-activation config)
348 "Return the activation GEXP for CONFIG."
349 (with-imported-modules '((guix build utils))
350 #~(begin
351 (use-modules (guix build utils))
352
353 (define (touch file-name)
354 (call-with-output-file file-name (const #t)))
355
356 ;; Make sure /etc/ssh can be read by the 'sshd' user.
357 (mkdir-p "/etc/ssh")
358 (chmod "/etc/ssh" #o755)
359 (mkdir-p (dirname #$(openssh-configuration-pid-file config)))
360
361 ;; 'sshd' complains if the authorized-key directory and its parents
362 ;; are group-writable, which rules out /gnu/store. Thus we copy the
363 ;; authorized-key directory to /etc.
364 (catch 'system-error
365 (lambda ()
366 (delete-file-recursively "/etc/authorized_keys.d"))
367 (lambda args
368 (unless (= ENOENT (system-error-errno args))
369 (apply throw args))))
370 (copy-recursively #$(authorized-key-directory
371 (openssh-authorized-keys config))
372 "/etc/ssh/authorized_keys.d")
373
374 (chmod "/etc/ssh/authorized_keys.d" #o555)
375
376 (let ((lastlog "/var/log/lastlog"))
377 (when #$(openssh-configuration-print-last-log? config)
378 (unless (file-exists? lastlog)
379 (touch lastlog))))
380
381 ;; Generate missing host keys.
382 (system* (string-append #$(openssh-configuration-openssh config)
383 "/bin/ssh-keygen") "-A"))))
384
385 (define (authorized-key-directory keys)
386 "Return a directory containing the authorized keys specified in KEYS, a list
387 of user-name/file-like tuples."
388 (define build
389 (with-imported-modules (source-module-closure '((guix build utils)))
390 #~(begin
391 (use-modules (ice-9 match) (srfi srfi-26)
392 (guix build utils))
393
394 (mkdir #$output)
395 (for-each (match-lambda
396 ((user keys ...)
397 (let ((file (string-append #$output "/" user)))
398 (call-with-output-file file
399 (lambda (port)
400 (for-each (lambda (key)
401 (call-with-input-file key
402 (cut dump-port <> port)))
403 keys))))))
404 '#$keys))))
405
406 (computed-file "openssh-authorized-keys" build))
407
408 (define (openssh-config-file config)
409 "Return the sshd configuration file corresponding to CONFIG."
410 (computed-file
411 "sshd_config"
412 #~(begin
413 (use-modules (ice-9 match))
414 (call-with-output-file #$output
415 (lambda (port)
416 (display "# Generated by 'openssh-service'.\n" port)
417 (format port "Port ~a\n"
418 #$(number->string
419 (openssh-configuration-port-number config)))
420 (format port "PermitRootLogin ~a\n"
421 #$(match (openssh-configuration-permit-root-login config)
422 (#t "yes")
423 (#f "no")
424 ('without-password "without-password")))
425 (format port "PermitEmptyPasswords ~a\n"
426 #$(if (openssh-configuration-allow-empty-passwords? config)
427 "yes" "no"))
428 (format port "PasswordAuthentication ~a\n"
429 #$(if (openssh-configuration-password-authentication? config)
430 "yes" "no"))
431 (format port "PubkeyAuthentication ~a\n"
432 #$(if (openssh-configuration-public-key-authentication?
433 config)
434 "yes" "no"))
435 (format port "X11Forwarding ~a\n"
436 #$(if (openssh-configuration-x11-forwarding? config)
437 "yes" "no"))
438 (format port "AllowAgentForwarding ~a\n"
439 #$(if (openssh-configuration-allow-agent-forwarding? config)
440 "yes" "no"))
441 (format port "AllowTcpForwarding ~a\n"
442 #$(if (openssh-configuration-allow-tcp-forwarding? config)
443 "yes" "no"))
444 (format port "GatewayPorts ~a\n"
445 #$(if (openssh-configuration-gateway-ports? config)
446 "yes" "no"))
447 (format port "PidFile ~a\n"
448 #$(openssh-configuration-pid-file config))
449 (format port "ChallengeResponseAuthentication ~a\n"
450 #$(if (openssh-challenge-response-authentication? config)
451 "yes" "no"))
452 (format port "UsePAM ~a\n"
453 #$(if (openssh-configuration-use-pam? config)
454 "yes" "no"))
455 (format port "PrintLastLog ~a\n"
456 #$(if (openssh-configuration-print-last-log? config)
457 "yes" "no"))
458 (format port "LogLevel ~a\n"
459 #$(string-upcase
460 (symbol->string
461 (openssh-configuration-log-level config))))
462
463 ;; Add '/etc/authorized_keys.d/%u', which we populate.
464 (format port "AuthorizedKeysFile \
465 .ssh/authorized_keys .ssh/authorized_keys2 /etc/ssh/authorized_keys.d/%u\n")
466
467 (for-each (lambda (s) (format port "AcceptEnv ~a\n" s))
468 '#$(openssh-configuration-accepted-environment config))
469
470 (for-each
471 (match-lambda
472 ((name command) (format port "Subsystem\t~a\t~a\n" name command)))
473 '#$(openssh-configuration-subsystems config))
474 #t)))))
475
476 (define (openssh-shepherd-service config)
477 "Return a <shepherd-service> for openssh with CONFIG."
478
479 (define pid-file
480 (openssh-configuration-pid-file config))
481
482 (define openssh-command
483 #~(list (string-append #$(openssh-configuration-openssh config) "/sbin/sshd")
484 "-D" "-f" #$(openssh-config-file config)))
485
486 (list (shepherd-service
487 (documentation "OpenSSH server.")
488 (requirement '(syslogd loopback))
489 (provision '(ssh-daemon))
490 (start #~(make-forkexec-constructor #$openssh-command
491 #:pid-file #$pid-file))
492 (stop #~(make-kill-destructor))
493 (auto-start? (openssh-auto-start? config)))))
494
495 (define (openssh-pam-services config)
496 "Return a list of <pam-services> for sshd with CONFIG."
497 (list (unix-pam-service
498 "sshd"
499 #:allow-empty-passwords?
500 (openssh-configuration-allow-empty-passwords? config))))
501
502 (define (extend-openssh-authorized-keys config keys)
503 "Extend CONFIG with the extra authorized keys listed in KEYS."
504 (openssh-configuration
505 (inherit config)
506 (authorized-keys
507 (append (openssh-authorized-keys config) keys))))
508
509 (define openssh-service-type
510 (service-type (name 'openssh)
511 (description
512 "Run the OpenSSH secure shell (SSH) server, @command{sshd}.")
513 (extensions
514 (list (service-extension shepherd-root-service-type
515 openssh-shepherd-service)
516 (service-extension pam-root-service-type
517 openssh-pam-services)
518 (service-extension activation-service-type
519 openssh-activation)
520 (service-extension account-service-type
521 (const %openssh-accounts))))
522 (compose concatenate)
523 (extend extend-openssh-authorized-keys)
524 (default-value (openssh-configuration))))
525
526 \f
527 ;;;
528 ;;; Dropbear.
529 ;;;
530
531 (define-record-type* <dropbear-configuration>
532 dropbear-configuration make-dropbear-configuration
533 dropbear-configuration?
534 (dropbear dropbear-configuration-dropbear
535 (default dropbear))
536 (port-number dropbear-configuration-port-number
537 (default 22))
538 (syslog-output? dropbear-configuration-syslog-output?
539 (default #t))
540 (pid-file dropbear-configuration-pid-file
541 (default "/var/run/dropbear.pid"))
542 (root-login? dropbear-configuration-root-login?
543 (default #f))
544 (allow-empty-passwords? dropbear-configuration-allow-empty-passwords?
545 (default #f))
546 (password-authentication? dropbear-configuration-password-authentication?
547 (default #t)))
548
549 (define (dropbear-activation config)
550 "Return the activation gexp for CONFIG."
551 #~(begin
552 (use-modules (guix build utils))
553 (mkdir-p "/etc/dropbear")))
554
555 (define (dropbear-shepherd-service config)
556 "Return a <shepherd-service> for dropbear with CONFIG."
557 (define dropbear
558 (dropbear-configuration-dropbear config))
559
560 (define pid-file
561 (dropbear-configuration-pid-file config))
562
563 (define dropbear-command
564 #~(list (string-append #$dropbear "/sbin/dropbear")
565
566 ;; '-R' allows host keys to be automatically generated upon first
567 ;; connection, at a time when /dev/urandom is more likely securely
568 ;; seeded.
569 "-F" "-R"
570
571 "-p" #$(number->string (dropbear-configuration-port-number config))
572 "-P" #$pid-file
573 #$@(if (dropbear-configuration-syslog-output? config) '() '("-E"))
574 #$@(if (dropbear-configuration-root-login? config) '() '("-w"))
575 #$@(if (dropbear-configuration-password-authentication? config)
576 '()
577 '("-s" "-g"))
578 #$@(if (dropbear-configuration-allow-empty-passwords? config)
579 '("-B")
580 '())))
581
582 (define requires
583 (if (dropbear-configuration-syslog-output? config)
584 '(networking syslogd) '(networking)))
585
586 (list (shepherd-service
587 (documentation "Dropbear SSH server.")
588 (requirement requires)
589 (provision '(ssh-daemon))
590 (start #~(make-forkexec-constructor #$dropbear-command
591 #:pid-file #$pid-file))
592 (stop #~(make-kill-destructor)))))
593
594 (define dropbear-service-type
595 (service-type (name 'dropbear)
596 (description
597 "Run the Dropbear secure shell (SSH) server.")
598 (extensions
599 (list (service-extension shepherd-root-service-type
600 dropbear-shepherd-service)
601 (service-extension activation-service-type
602 dropbear-activation)))))
603
604 (define* (dropbear-service #:optional (config (dropbear-configuration)))
605 "Run the @uref{https://matt.ucc.asn.au/dropbear/dropbear.html,Dropbear SSH
606 daemon} with the given @var{config}, a @code{<dropbear-configuration>}
607 object."
608 (service dropbear-service-type config))
609
610 ;;; ssh.scm ends here