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 "2013-06-21">
6
<!ENTITY % common SYSTEM "../common.ent">
4
<!ENTITY VERSION "1.0">
5
<!ENTITY COMMANDNAME "password-request">
6
<!ENTITY TIMESTAMP "2008-09-04">
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>
133
115
</refsynopsisdiv>
135
117
<refsect1 id="description">
136
118
<title>DESCRIPTION</title>
138
120
<command>&COMMANDNAME;</command> is a client program that
139
121
communicates with <citerefentry><refentrytitle
140
122
>mandos</refentrytitle><manvolnum>8</manvolnum></citerefentry>
141
to get a password. In slightly more detail, this client program
142
brings up network interfaces, uses the interfaces’ IPv6
143
link-local addresses to get network connectivity, uses Zeroconf
144
to find servers on the local network, and communicates with
145
servers using TLS with an OpenPGP key to ensure authenticity and
146
confidentiality. This client program keeps running, trying all
147
servers on the network, until it receives a satisfactory reply
148
or a TERM signal. After all servers have been tried, all
149
servers are periodically retried. If no servers are found it
150
will wait indefinitely for new servers to appear.
153
The network interfaces are selected like this: If any interfaces
154
are specified using the <option>--interface</option> option,
155
those interface are used. Otherwise,
156
<command>&COMMANDNAME;</command> will use all interfaces that
157
are not loopback interfaces, are not point-to-point interfaces,
158
are capable of broadcasting and do not have the NOARP flag (see
159
<citerefentry><refentrytitle>netdevice</refentrytitle>
160
<manvolnum>7</manvolnum></citerefentry>). (If the
161
<option>--connect</option> option is used, point-to-point
162
interfaces and non-broadcast interfaces are accepted.) If any
163
used interfaces are not up and running, they are first taken up
164
(and later taken down again on program exit).
167
Before network interfaces are 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 received.
171
130
This program is not meant to be run directly; it is really meant
228
<term><option>--interface=<replaceable
229
>NAME</replaceable><arg rep='repeat'>,<replaceable
230
>NAME</replaceable></arg></option></term>
187
<term><option>--interface=
188
<replaceable>NAME</replaceable></option></term>
232
<replaceable>NAME</replaceable><arg rep='repeat'>,<replaceable
233
>NAME</replaceable></arg></option></term>
190
<replaceable>NAME</replaceable></option></term>
236
Comma separated list of network interfaces that will be
237
brought up and scanned for Mandos servers to connect to.
238
The default is the empty string, which will automatically
239
use all appropriate interfaces.
242
If the <option>--connect</option> option is used, and
243
exactly one interface name is specified (except
244
<quote><literal>none</literal></quote>), this specifies
245
the interface to use to connect to the address given.
248
Note that since this program will normally run in the
249
initial RAM disk environment, the interface must be an
250
interface which exists at that stage. Thus, the interface
251
can normally not be a pseudo-interface such as
252
<quote>br0</quote> or <quote>tun0</quote>; such interfaces
253
will not exist until much later in the boot process, and
254
can not be used by this program, unless created by a
255
<quote>network hook</quote> — see <xref
256
linkend="network-hooks"/>.
259
<replaceable>NAME</replaceable> can be the string
260
<quote><literal>none</literal></quote>; this will make
261
<command>&COMMANDNAME;</command> not bring up
262
<emphasis>any</emphasis> interfaces specified
263
<emphasis>after</emphasis> this string. This is not
264
recommended, and only meant for advanced users.
193
Network interface that will be brought up and scanned for
194
Mandos servers to connect to. The default it
195
<quote><literal>eth0</literal></quote>.
198
If the <option>--connect</option> option is used, this
199
specifies the interface to use to connect to the address
318
<term><option>--delay=<replaceable
319
>SECONDS</replaceable></option></term>
322
After bringing a network interface up, the program waits
323
for the interface to arrive in a <quote>running</quote>
324
state before proceeding. During this time, the kernel log
325
level will be lowered to reduce clutter on the system
326
console, alleviating any other plugins which might be
327
using the system console. This option sets the upper
328
limit of seconds to wait. The default is 2.5 seconds.
334
<term><option>--retry=<replaceable
335
>SECONDS</replaceable></option></term>
338
All Mandos servers are tried repeatedly until a password
339
is received. This value specifies, in seconds, how long
340
between each successive try <emphasis>for the same
341
server</emphasis>. The default is 10 seconds.
347
<term><option>--network-hook-dir=<replaceable
348
>DIR</replaceable></option></term>
351
Network hook directory. The default directory is
352
<quote><filename class="directory"
353
>/lib/mandos/network-hooks.d</filename></quote>.
359
254
<term><option>--debug</option></term>
416
311
<filename>/etc/crypttab</filename>, but it would then be
417
312
impossible to enter a password for the encrypted root disk at
418
313
the console, since this program does not read from the console
419
at all. This is why a separate plugin runner (<citerefentry>
420
<refentrytitle>plugin-runner</refentrytitle>
421
<manvolnum>8mandos</manvolnum></citerefentry>) is used to run
422
both this program and others in in parallel,
423
<emphasis>one</emphasis> of which (<citerefentry>
314
at all. This is why a separate plugin (<citerefentry>
424
315
<refentrytitle>password-prompt</refentrytitle>
425
<manvolnum>8mandos</manvolnum></citerefentry>) will prompt for
426
passwords on the system console.
316
<manvolnum>8mandos</manvolnum></citerefentry>) does that, which
317
will be run in parallel to this one by the plugin runner.
453
<refsect1 id="network-hooks">
454
<title>NETWORK HOOKS</title>
456
If a network interface like a bridge or tunnel is required to
457
find a Mandos server, this requires the interface to be up and
458
running before <command>&COMMANDNAME;</command> starts looking
459
for Mandos servers. This can be accomplished by creating a
460
<quote>network hook</quote> program, and placing it in a special
464
Before the network is used (and again before program exit), any
465
runnable programs found in the network hook directory are run
466
with the argument <quote><literal>start</literal></quote> or
467
<quote><literal>stop</literal></quote>. This should bring up or
468
down, respectively, any network interface which
469
<command>&COMMANDNAME;</command> should use.
471
<refsect2 id="hook-requirements">
472
<title>REQUIREMENTS</title>
474
A network hook must be an executable file, and its name must
475
consist entirely of upper and lower case letters, digits,
476
underscores, periods, and hyphens.
479
A network hook will receive one argument, which can be one of
484
<term><literal>start</literal></term>
487
This should make the network hook create (if necessary)
488
and bring up a network interface.
493
<term><literal>stop</literal></term>
496
This should make the network hook take down a network
497
interface, and delete it if it did not exist previously.
502
<term><literal>files</literal></term>
505
This should make the network hook print, <emphasis>one
506
file per line</emphasis>, all the files needed for it to
507
run. (These files will be copied into the initial RAM
508
filesystem.) Typical use is for a network hook which is
509
a shell script to print its needed binaries.
512
It is not necessary to print any non-executable files
513
already in the network hook directory, these will be
514
copied implicitly if they otherwise satisfy the name
520
<term><literal>modules</literal></term>
523
This should make the network hook print, <emphasis>on
524
separate lines</emphasis>, all the kernel modules needed
525
for it to run. (These modules will be copied into the
526
initial RAM filesystem.) For instance, a tunnel
528
<quote><literal>tun</literal></quote> module.
534
The network hook will be provided with a number of environment
539
<term><envar>MANDOSNETHOOKDIR</envar></term>
542
The network hook directory, specified to
543
<command>&COMMANDNAME;</command> by the
544
<option>--network-hook-dir</option> option. Note: this
545
should <emphasis>always</emphasis> be used by the
546
network hook to refer to itself or any files in the hook
547
directory it may require.
552
<term><envar>DEVICE</envar></term>
555
The network interfaces, as specified to
556
<command>&COMMANDNAME;</command> by the
557
<option>--interface</option> option, combined to one
558
string and separated by commas. If this is set, and
559
does not contain the interface a hook will bring up,
560
there is no reason for a hook to continue.
565
<term><envar>MODE</envar></term>
568
This will be the same as the first argument;
569
i.e. <quote><literal>start</literal></quote>,
570
<quote><literal>stop</literal></quote>,
571
<quote><literal>files</literal></quote>, or
572
<quote><literal>modules</literal></quote>.
577
<term><envar>VERBOSITY</envar></term>
580
This will be the <quote><literal>1</literal></quote> if
581
the <option>--debug</option> option is passed to
582
<command>&COMMANDNAME;</command>, otherwise
583
<quote><literal>0</literal></quote>.
588
<term><envar>DELAY</envar></term>
591
This will be the same as the <option>--delay</option>
592
option passed to <command>&COMMANDNAME;</command>. Is
593
only set if <envar>MODE</envar> is
594
<quote><literal>start</literal></quote> or
595
<quote><literal>stop</literal></quote>.
600
<term><envar>CONNECT</envar></term>
603
This will be the same as the <option>--connect</option>
604
option passed to <command>&COMMANDNAME;</command>. Is
605
only set if <option>--connect</option> is passed and
606
<envar>MODE</envar> is
607
<quote><literal>start</literal></quote> or
608
<quote><literal>stop</literal></quote>.
614
A hook may not read from standard input, and should be
615
restrictive in printing to standard output or standard error
616
unless <varname>VERBOSITY</varname> is
617
<quote><literal>1</literal></quote>.
622
<refsect1 id="files">
623
345
<title>FILES</title>
736
446
The only remaining weak point is that someone with physical
737
447
access to the client hard drive might turn off the client
738
448
computer, read the OpenPGP keys directly from the hard drive,
739
and communicate with the server. To safeguard against this, the
740
server is supposed to notice the client disappearing and stop
741
giving out the encrypted data. Therefore, it is important to
742
set the timeout and checker interval values tightly on the
743
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
744
454
>mandos</refentrytitle><manvolnum>8</manvolnum></citerefentry>.