1
1
<?xml version="1.0" encoding="UTF-8"?>
2
2
<!DOCTYPE refentry PUBLIC "-//OASIS//DTD DocBook XML V4.5//EN"
3
3
"http://www.oasis-open.org/docbook/xml/4.5/docbookx.dtd" [
4
<!ENTITY COMMANDNAME "mandos-client">
5
<!ENTITY TIMESTAMP "2012-01-01">
6
<!ENTITY % common SYSTEM "../common.ent">
4
<!ENTITY VERSION "1.0">
5
<!ENTITY COMMANDNAME "password-request">
6
<!ENTITY TIMESTAMP "2008-09-03">
10
9
<refentry xmlns:xi="http://www.w3.org/2001/XInclude">
12
11
<title>Mandos Manual</title>
13
<!-- NWalsh’s docbook scripts use this to generate the footer: -->
12
<!-- Nwalsh’s docbook scripts use this to generate the footer: -->
14
13
<productname>Mandos</productname>
15
<productnumber>&version;</productnumber>
14
<productnumber>&VERSION;</productnumber>
16
15
<date>&TIMESTAMP;</date>
19
18
<firstname>Björn</firstname>
20
19
<surname>Påhlsson</surname>
22
<email>belorn@recompile.se</email>
21
<email>belorn@fukt.bsnet.se</email>
26
25
<firstname>Teddy</firstname>
27
26
<surname>Hogeborn</surname>
29
<email>teddy@recompile.se</email>
28
<email>teddy@fukt.bsnet.se</email>
37
34
<holder>Teddy Hogeborn</holder>
38
35
<holder>Björn Påhlsson</holder>
40
37
<xi:include href="../legalnotice.xml"/>
44
41
<refentrytitle>&COMMANDNAME;</refentrytitle>
45
42
<manvolnum>8mandos</manvolnum>
131
115
</refsynopsisdiv>
133
117
<refsect1 id="description">
134
118
<title>DESCRIPTION</title>
136
120
<command>&COMMANDNAME;</command> is a client program that
137
121
communicates with <citerefentry><refentrytitle
138
122
>mandos</refentrytitle><manvolnum>8</manvolnum></citerefentry>
139
to get a password. In slightly more detail, this client program
140
brings up a network interface, uses the interface’s IPv6
141
link-local address to get network connectivity, uses Zeroconf to
142
find servers on the local network, and communicates with servers
143
using TLS with an OpenPGP key to ensure authenticity and
144
confidentiality. This client program keeps running, trying all
145
servers on the network, until it receives a satisfactory reply
146
or a TERM signal. After all servers have been tried, all
147
servers are periodically retried. If no servers are found it
148
will wait indefinitely for new servers to appear.
151
The network interface is selected like this: If an interface is
152
specified using the <option>--interface</option> option, that
153
interface is used. Otherwise, <command>&COMMANDNAME;</command>
154
will choose any interface that is up and running and is not a
155
loopback interface, is not a point-to-point interface, is
156
capable of broadcasting and does not have the NOARP flag (see
157
<citerefentry><refentrytitle>netdevice</refentrytitle>
158
<manvolnum>7</manvolnum></citerefentry>). (If the
159
<option>--connect</option> option is used, point-to-point
160
interfaces and non-broadcast interfaces are accepted.) If no
161
acceptable interfaces are found, re-run the check but without
162
the <quote>up and running</quote> requirement, and manually take
163
the selected interface up (and later take it down on program
167
Before a network interface is selected, all <quote>network
168
hooks</quote> are run; see <xref linkend="network-hooks"/>.
123
to get a password. It uses IPv6 link-local addresses to get
124
network connectivity, Zeroconf to find servers, and TLS with an
125
OpenPGP key to ensure authenticity and confidentiality. It
126
keeps running, trying all servers on the network, until it
127
receives a satisfactory reply or a TERM signal is recieved.
171
130
This program is not meant to be run directly; it is really meant
228
<term><option>--interface=<replaceable
229
>NAME</replaceable></option></term>
187
<term><option>--interface=
188
<replaceable>NAME</replaceable></option></term>
231
190
<replaceable>NAME</replaceable></option></term>
234
193
Network interface that will be brought up and scanned for
235
Mandos servers to connect to. The default is the empty
236
string, which will automatically choose an appropriate
194
Mandos servers to connect to. The default it
195
<quote><literal>eth0</literal></quote>.
240
198
If the <option>--connect</option> option is used, this
241
199
specifies the interface to use to connect to the address
245
Note that since this program will normally run in the
246
initial RAM disk environment, the interface must be an
247
interface which exists at that stage. Thus, the interface
248
can not be a pseudo-interface such as <quote>br0</quote>
249
or <quote>tun0</quote>; such interfaces will not exist
250
until much later in the boot process, and can not be used
251
by this program, unless created by a <quote>network
252
hook</quote> — see <xref linkend="network-hooks"/>.
255
<replaceable>NAME</replaceable> can be the string
256
<quote><literal>none</literal></quote>; this will not use
257
any specific interface, and will not bring up an interface
258
on startup. This is not recommended, and only meant for
313
<term><option>--delay=<replaceable
314
>SECONDS</replaceable></option></term>
317
After bringing the network interface up, the program waits
318
for the interface to arrive in a <quote>running</quote>
319
state before proceeding. During this time, the kernel log
320
level will be lowered to reduce clutter on the system
321
console, alleviating any other plugins which might be
322
using the system console. This option sets the upper
323
limit of seconds to wait. The default is 2.5 seconds.
329
<term><option>--retry=<replaceable
330
>SECONDS</replaceable></option></term>
333
All Mandos servers are tried repeatedly until a password
334
is received. This value specifies, in seconds, how long
335
between each successive try <emphasis>for the same
336
server</emphasis>. The default is 10 seconds.
342
<term><option>--network-hook-dir=<replaceable
343
>DIR</replaceable></option></term>
346
Network hook directory. The default directory is
347
<quote><filename class="directory"
348
>/lib/mandos/network-hooks.d</filename></quote>.
354
254
<term><option>--debug</option></term>
411
311
<filename>/etc/crypttab</filename>, but it would then be
412
312
impossible to enter a password for the encrypted root disk at
413
313
the console, since this program does not read from the console
414
at all. This is why a separate plugin runner (<citerefentry>
415
<refentrytitle>plugin-runner</refentrytitle>
416
<manvolnum>8mandos</manvolnum></citerefentry>) is used to run
417
both this program and others in in parallel,
418
<emphasis>one</emphasis> of which (<citerefentry>
314
at all. This is why a separate plugin (<citerefentry>
419
315
<refentrytitle>password-prompt</refentrytitle>
420
<manvolnum>8mandos</manvolnum></citerefentry>) will prompt for
421
passwords on the system console.
316
<manvolnum>8mandos</manvolnum></citerefentry>) does that, which
317
will be run in parallell to this one by the plugin runner.
448
<refsect1 id="network-hooks">
449
<title>NETWORK HOOKS</title>
451
If a network interface like a bridge or tunnel is required to
452
find a Mandos server, this requires the interface to be up and
453
running before <command>&COMMANDNAME;</command> starts looking
454
for Mandos servers. This can be accomplished by creating a
455
<quote>network hook</quote> program, and placing it in a special
459
Before the network is used (and again before program exit), any
460
runnable programs found in the network hook directory are run
461
with the argument <quote><literal>start</literal></quote> or
462
<quote><literal>stop</literal></quote>. This should bring up or
463
down, respectively, any network interface which
464
<command>&COMMANDNAME;</command> should use.
466
<refsect2 id="hook-requirements">
467
<title>REQUIREMENTS</title>
469
A network hook must be an executable file, and its name must
470
consist entirely of upper and lower case letters, digits,
471
underscores, periods, and hyphens.
474
A network hook will receive one argument, which can be one of
479
<term><literal>start</literal></term>
482
This should make the network hook create (if necessary)
483
and bring up a network interface.
488
<term><literal>stop</literal></term>
491
This should make the network hook take down a network
492
interface, and delete it if it did not exist previously.
497
<term><literal>files</literal></term>
500
This should make the network hook print, <emphasis>one
501
file per line</emphasis>, all the files needed for it to
502
run. (These files will be copied into the initial RAM
503
filesystem.) Typical use is for a network hook which is
504
a shell script to print its needed binaries.
507
It is not necessary to print any non-executable files
508
already in the network hook directory, these will be
509
copied implicitly if they otherwise satisfy the name
515
<term><literal>modules</literal></term>
518
This should make the network hook print, <emphasis>on
519
separate lines</emphasis>, all the kernel modules needed
520
for it to run. (These modules will be copied into the
521
initial RAM filesystem.) For instance, a tunnel
523
<quote><literal>tun</literal></quote> module.
529
The network hook will be provided with a number of environment
534
<term><envar>MANDOSNETHOOKDIR</envar></term>
537
The network hook directory, specified to
538
<command>&COMMANDNAME;</command> by the
539
<option>--network-hook-dir</option> option. Note: this
540
should <emphasis>always</emphasis> be used by the
541
network hook to refer to itself or any files in the hook
542
directory it may require.
547
<term><envar>DEVICE</envar></term>
550
The network interface, as specified to
551
<command>&COMMANDNAME;</command> by the
552
<option>--interface</option> option. If this is not the
553
interface a hook will bring up, there is no reason for a
559
<term><envar>MODE</envar></term>
562
This will be the same as the first argument;
563
i.e. <quote><literal>start</literal></quote>,
564
<quote><literal>stop</literal></quote>,
565
<quote><literal>files</literal></quote>, or
566
<quote><literal>modules</literal></quote>.
571
<term><envar>VERBOSITY</envar></term>
574
This will be the <quote><literal>1</literal></quote> if
575
the <option>--debug</option> option is passed to
576
<command>&COMMANDNAME;</command>, otherwise
577
<quote><literal>0</literal></quote>.
582
<term><envar>DELAY</envar></term>
585
This will be the same as the <option>--delay</option>
586
option passed to <command>&COMMANDNAME;</command>. Is
587
only set if <envar>MODE</envar> is
588
<quote><literal>start</literal></quote> or
589
<quote><literal>stop</literal></quote>.
594
<term><envar>CONNECT</envar></term>
597
This will be the same as the <option>--connect</option>
598
option passed to <command>&COMMANDNAME;</command>. Is
599
only set if <option>--connect</option> is passed and
600
<envar>MODE</envar> is
601
<quote><literal>start</literal></quote> or
602
<quote><literal>stop</literal></quote>.
608
A hook may not read from standard input, and should be
609
restrictive in printing to standard output or standard error
610
unless <varname>VERBOSITY</varname> is
611
<quote><literal>1</literal></quote>.
616
<refsect1 id="files">
617
345
<title>FILES</title>
730
446
The only remaining weak point is that someone with physical
731
447
access to the client hard drive might turn off the client
732
448
computer, read the OpenPGP keys directly from the hard drive,
733
and communicate with the server. To safeguard against this, the
734
server is supposed to notice the client disappearing and stop
735
giving out the encrypted data. Therefore, it is important to
736
set the timeout and checker interval values tightly on the
737
server. See <citerefentry><refentrytitle
449
and communicate with the server. The defense against this is
450
that the server is supposed to notice the client disappearing
451
and will stop giving out the encrypted data. Therefore, it is
452
important to set the timeout and checker interval values tightly
453
on the server. See <citerefentry><refentrytitle
738
454
>mandos</refentrytitle><manvolnum>8</manvolnum></citerefentry>.