creds_msdos revision 1.1 
1#!/bin/sh
2#
3# $NetBSD: creds_msdos,v 1.1 2019/06/11 10:50:57 mrg Exp $
4#
5# Copyright (c) 2019 Matthew R. Green
6# All rights reserved.
7#
8# Redistribution and use in source and binary forms, with or without
9# modification, are permitted provided that the following conditions
10# are met:
11# 1. Redistributions of source code must retain the above copyright
12#    notice, this list of conditions and the following disclaimer.
13# 2. Redistributions in binary form must reproduce the above copyright
14#    notice, this list of conditions and the following disclaimer in the
15#    documentation and/or other materials provided with the distribution.
16# 3. The name of the author may not be used to endorse or promote products
17#    derived from this software without specific prior written permission.
18#
19# THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
20# IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
21# OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
22# IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
23# INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
24# BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
25# LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
26# AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
27# OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28# OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29# SUCH DAMAGE.
30
31#
32# If "creds_msdos_partition" is an msdos partition and has a creds.txt
33# in it, perform these commands:
34#	"sshkeyfile <user> <path on msdos>"
35#	"sshkey <user> <entry>"
36# 	"useraddhash <user> <passwd hash>"
37# 	"useradd <user> <passwd>"
38# If the "useradd" method is used, this the creds.txt file will be
39# shredded and deleted with rm -P.
40
41# PROVIDE: creds_msdos
42# REQUIRE: mountall
43
44$_rc_subr_loaded . /etc/rc.subr
45
46name="creds_msdos"
47start_cmd="creds_msdos_start"
48stop_cmd=":"
49fstab_file=/etc/fstab
50
51fail() {
52	echo "$@" 1>&2
53	exit 1
54}
55
56sshkey_setup() {
57	local user="$1"
58	local group="wheel"
59
60	# don't create existing users
61	id=$(id -u $user 2>/dev/null)
62	if [ $? -ne 0 ]; then
63		useradd -m -G "${group}" "$user" || fail "Useradd failed."
64	fi
65
66	eval sshdir=~"${user}/.ssh"
67	eval mkdir -p -m 755 "${sshdir}" || fail "mkdir ~/.ssh failed."
68	chown "${user}" "${sshdir}"
69	eval userkeys="${sshdir}/authorized_keys"
70}
71
72sshkey_finish() {
73	local user="$1"
74	local userkeys="$2"
75
76	chmod 644 "${userkeys}"
77	chown "${user}" "${userkeys}"
78}
79
80do_sshkeyfile() {
81	local user="$1"
82	local newkeys="${creds_msdos_partition}/$2"
83
84	if [ ! -f "${newkeys}" ]; then
85		return
86	fi
87
88	sshkey_setup "$user"
89
90	# check entry is not present
91	while read type keydata name; do
92		if fgrep -q "${keydata}" "${userkeys}" 2>/dev/null; then
93			continue
94		fi
95		echo "${type} ${keydata} ${name}" >> "${userkeys}"
96	done < "${newkeys}"
97
98	sshkey_finish "$user" "${userkeys}"
99}
100
101do_sshkey() {
102	local user="$1"
103	local newkey="$2"
104
105	sshkey_setup "$user"
106
107	echo "${newkey}" >> "${userkeys}"
108
109	sshkey_finish "$user" "${userkeys}"
110}
111
112do_useraddpwhash() {
113	local user="$1"
114	local pwhash="$2"
115	local group="wheel"
116
117	# don't add to existing users
118	id=$(id -u "${user}" 2>/dev/null)
119	if [ $? -eq 0 ]; then
120		return
121	fi
122
123	useradd -m -p "${pwhash}" -G "${group}" "${user}" || fail "Useradd failed."
124}
125
126do_useradd() {
127	local user="$1"
128	local password="$2"
129
130	local pwhash=$(pwhash "$password")
131	do_useraddpwhash "${user}" "${pwhash}"
132}
133
134creds_msdos_start()
135{
136	if [ -z "${creds_msdos_partition}" ]; then
137		echo "Not looking for credientials on msdos"
138		return;
139	fi
140	check_fs=
141	while read junk1 mp fstype junk2; do
142		if [ "${mp}" != "${creds_msdos_partition}" ]; then
143			continue
144		fi
145		if [ "${fstype}" != "msdos" ]; then
146			echo "Not checking for creds on ${creds_msdos_partition}: not an msdos file system"
147			return;
148		fi
149		break
150	done < "${fstab_file}"
151
152	delete_creds=no
153	creds_file="${creds_msdos_partition}/creds.txt"
154
155	if [ -f "${creds_file}" ]; then
156		while read type user arg1; do
157			case "$type" in
158			\#*|'')
159				continue
160				;;
161			sshkeyfile)
162				echo "Added user ${user} via ssh key file method."
163				do_sshkeyfile "${user}" "${arg1}"
164				;;
165			sshkey)
166				echo "Added user ${user} via ssh key string method."
167				do_sshkey "${user}" "${arg1}"
168				;;
169			useraddpwhash)
170				echo "Added user ${user} via password hash method."
171				do_useraddpwhash "${user}" "${arg1}"
172				;;
173			useradd)
174				echo "Added user ${user} via password method, shredding credentials file."
175				do_useradd "${user}" "${arg1}"
176				delete_creds=yes
177				;;
178			*)
179				echo "Do not understand '$type' creds" 1>&2
180				exit 1
181				;;
182			esac
183		done < "${creds_file}"
184	fi
185
186	if [ $delete_creds = yes ]; then
187		rm -P -f "${creds_file}"
188	fi
189}
190
191load_rc_config $name
192run_rc_command "$1"
193