diff options
Diffstat (limited to 'gnu/services')
| -rw-r--r-- | gnu/services/ssh.scm | 140 |
1 files changed, 140 insertions, 0 deletions
diff --git a/gnu/services/ssh.scm b/gnu/services/ssh.scm new file mode 100644 index 0000000000..6d40cb489b --- /dev/null +++ b/gnu/services/ssh.scm @@ -0,0 +1,140 @@ +;;; GNU Guix --- Functional package management for GNU +;;; Copyright © 2014 Ludovic Courtès <ludo@gnu.org> +;;; +;;; This file is part of GNU Guix. +;;; +;;; GNU Guix is free software; you can redistribute it and/or modify it +;;; under the terms of the GNU General Public License as published by +;;; the Free Software Foundation; either version 3 of the License, or (at +;;; your option) any later version. +;;; +;;; GNU Guix is distributed in the hope that it will be useful, but +;;; WITHOUT ANY WARRANTY; without even the implied warranty of +;;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the +;;; GNU General Public License for more details. +;;; +;;; You should have received a copy of the GNU General Public License +;;; along with GNU Guix. If not, see <http://www.gnu.org/licenses/>. + +(define-module (gnu services ssh) + #:use-module (guix gexp) + #:use-module (gnu services) + #:use-module (gnu system linux) ; 'pam-service' + #:use-module (gnu packages lsh) + #:use-module (guix monads) + #:export (lsh-service)) + +;;; Commentary: +;;; +;;; This module implements secure shell (SSH) services. +;;; +;;; Code: + +(define %yarrow-seed + "/var/spool/lsh/yarrow-seed-file") + +(define (activation lsh host-key) + "Return the gexp to activate the LSH service for HOST-KEY." + #~(begin + (unless (file-exists? #$%yarrow-seed) + (system* (string-append #$lsh "/bin/lsh-make-seed") + "--sloppy" "-o" #$%yarrow-seed)) + + (unless (file-exists? #$host-key) + (mkdir-p (dirname #$host-key)) + (format #t "creating SSH host key '~a'...~%" #$host-key) + + ;; FIXME: We're just doing a simple pipeline, but 'system' cannot be + ;; used yet because /bin/sh might be dangling; factorize this somehow. + (let* ((in+out (pipe)) + (keygen (primitive-fork))) + (case keygen + ((0) + (close-port (car in+out)) + (close-fdes 1) + (dup2 (fileno (cdr in+out)) 1) + (execl (string-append #$lsh "/bin/lsh-keygen") + "lsh-keygen" "--server")) + (else + (let ((write-key (primitive-fork))) + (case write-key + ((0) + (close-port (cdr in+out)) + (close-fdes 0) + (dup2 (fileno (car in+out)) 0) + (execl (string-append #$lsh "/bin/lsh-writekey") + "lsh-writekey" "--server" "-o" #$host-key)) + (else + (close-port (car in+out)) + (close-port (cdr in+out)) + (waitpid keygen) + (waitpid write-key)))))))))) + +(define* (lsh-service #:key + (lsh lsh) + (host-key "/etc/lsh/host-key") + (interfaces '()) + (port-number 22) + (allow-empty-passwords? #f) + (root-login? #f) + (syslog-output? #t) + (x11-forwarding? #t) + (tcp/ip-forwarding? #t) + (password-authentication? #t) + (public-key-authentication? #t) + initialize?) + "Run the @command{lshd} program from @var{lsh} to listen on port @var{port-number}. +@var{host-key} must designate a file containing the host key, and readable +only by root. + +When @var{initialize?} is true, automatically create the seed and host key +upon service activation if they do not exist yet. This may take long and +require interaction. + +When @var{interfaces} is empty, lshd listens for connections on all the +network interfaces; otherwise, @var{interfaces} must be a list of host names +or addresses. + +@var{allow-empty-passwords?} specifies whether to accepts log-ins with empty +passwords, and @var{root-login?} specifies whether to accepts log-ins as +root. + +The other options should be self-descriptive." + (define lsh-command + (cons* #~(string-append #$lsh "/sbin/lshd") + #~(string-append "--host-key=" #$host-key) + #~(string-append "--password-helper=" #$lsh "/sbin/lsh-pam-checkpw") + #~(string-append "--subsystems=sftp=" #$lsh "/sbin/sftp-server") + "-p" (number->string port-number) + (if password-authentication? "--password" "--no-password") + (if public-key-authentication? + "--publickey" "--no-publickey") + (if root-login? + "--root-login" "--no-root-login") + (if x11-forwarding? + "--x11-forward" "--no-x11-forward") + (if tcp/ip-forwarding? + "--tcpip-forward" "--no-tcpip-forward") + (if (null? interfaces) + '() + (list (string-append "--interfaces=" + (string-join interfaces ",")))))) + + (with-monad %store-monad + (return (service + (documentation "GNU lsh SSH server") + (provision '(ssh-daemon)) + (requirement '(networking)) + (start #~(make-forkexec-constructor #$@lsh-command)) + (stop #~(make-kill-destructor)) + (pam-services + (list (unix-pam-service + "lshd" + #:allow-empty-passwords? allow-empty-passwords?))) + (activate #~(begin + (mkdir-p "/var/spool/lsh") + #$(if initialize? + (activation lsh host-key) + #t))))))) + +;;; ssh.scm ends here |