blob: 6d40cb489ba6708215eefd569e0062c61f09eac4 (
about) (
plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
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
|
