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 VERSION "1.0">
4
5
<!ENTITY COMMANDNAME "mandos">
5
<!ENTITY TIMESTAMP "2019-02-09">
6
<!ENTITY % common SYSTEM "common.ent">
6
<!ENTITY TIMESTAMP "2008-08-30">
10
9
<refentry xmlns:xi="http://www.w3.org/2001/XInclude">
12
11
<title>Mandos Manual</title>
13
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>
45
34
<holder>Teddy Hogeborn</holder>
46
35
<holder>Björn Påhlsson</holder>
48
<xi:include href="legalnotice.xml"/>
39
This manual page is free software: you can redistribute it
40
and/or modify it under the terms of the GNU General Public
41
License as published by the Free Software Foundation,
42
either version 3 of the License, or (at your option) any
47
This manual page is distributed in the hope that it will
48
be useful, but WITHOUT ANY WARRANTY; without even the
49
implied warranty of MERCHANTABILITY or FITNESS FOR A
50
PARTICULAR PURPOSE. See the GNU General Public License
55
You should have received a copy of the GNU General Public
56
License along with this program; If not, see
57
<ulink url="http://www.gnu.org/licenses/"/>.
52
63
<refentrytitle>&COMMANDNAME;</refentrytitle>
53
64
<manvolnum>8</manvolnum>
94
105
<replaceable>DIRECTORY</replaceable></option></arg>
96
107
<arg><option>--debug</option></arg>
98
<arg><option>--debuglevel
99
<replaceable>LEVEL</replaceable></option></arg>
101
<arg><option>--no-dbus</option></arg>
103
<arg><option>--no-ipv6</option></arg>
105
<arg><option>--no-restore</option></arg>
107
<arg><option>--statedir
108
<replaceable>DIRECTORY</replaceable></option></arg>
110
<arg><option>--socket
111
<replaceable>FD</replaceable></option></arg>
113
<arg><option>--foreground</option></arg>
115
<arg><option>--no-zeroconf</option></arg>
118
110
<command>&COMMANDNAME;</command>
119
111
<group choice="req">
112
<arg choice="plain"><option>-h</option></arg>
120
113
<arg choice="plain"><option>--help</option></arg>
121
<arg choice="plain"><option>-h</option></arg>
130
122
<arg choice="plain"><option>--check</option></arg>
132
124
</refsynopsisdiv>
134
126
<refsect1 id="description">
135
127
<title>DESCRIPTION</title>
137
129
<command>&COMMANDNAME;</command> is a server daemon which
138
130
handles incoming request for passwords for a pre-defined list of
139
client host computers. For an introduction, see
140
<citerefentry><refentrytitle>intro</refentrytitle>
141
<manvolnum>8mandos</manvolnum></citerefentry>. The Mandos server
142
uses Zeroconf to announce itself on the local network, and uses
143
TLS to communicate securely with and to authenticate the
144
clients. The Mandos server uses IPv6 to allow Mandos clients to
145
use IPv6 link-local addresses, since the clients will probably
146
not have any other addresses configured (see <xref
147
linkend="overview"/>). Any authenticated client is then given
148
the stored pre-encrypted password for that specific client.
131
client host computers. The Mandos server uses Zeroconf to
132
announce itself on the local network, and uses TLS to
133
communicate securely with and to authenticate the clients. The
134
Mandos server uses IPv6 to allow Mandos clients to use IPv6
135
link-local addresses, since the clients will probably not have
136
any other addresses configured (see <xref linkend="overview"/>).
137
Any authenticated client is then given the stored pre-encrypted
138
password for that specific client.
152
143
<refsect1 id="purpose">
153
144
<title>PURPOSE</title>
155
147
The purpose of this is to enable <emphasis>remote and unattended
156
148
rebooting</emphasis> of client host computer with an
157
149
<emphasis>encrypted root file system</emphasis>. See <xref
158
150
linkend="overview"/> for details.
162
155
<refsect1 id="options">
163
156
<title>OPTIONS</title>
160
<term><option>-h</option></term>
166
161
<term><option>--help</option></term>
167
<term><option>-h</option></term>
170
164
Show a help message and exit
170
<term><option>-i</option>
171
<replaceable>NAME</replaceable></term>
176
172
<term><option>--interface</option>
177
173
<replaceable>NAME</replaceable></term>
178
<term><option>-i</option>
179
<replaceable>NAME</replaceable></term>
181
175
<xi:include href="mandos-options.xml" xpointer="interface"/>
186
<term><option>--address
187
<replaceable>ADDRESS</replaceable></option></term>
189
<replaceable>ADDRESS</replaceable></option></term>
180
<term><literal>-a</literal>, <literal>--address <replaceable>
181
ADDRESS</replaceable></literal></term>
191
183
<xi:include href="mandos-options.xml" xpointer="address"/>
197
<replaceable>PORT</replaceable></option></term>
199
<replaceable>PORT</replaceable></option></term>
188
<term><literal>-p</literal>, <literal>--port <replaceable>
189
PORT</replaceable></literal></term>
201
191
<xi:include href="mandos-options.xml" xpointer="port"/>
206
<term><option>--check</option></term>
196
<term><literal>--check</literal></term>
209
199
Run the server’s self-tests. This includes any unit
216
<term><option>--debug</option></term>
206
<term><literal>--debug</literal></term>
218
208
<xi:include href="mandos-options.xml" xpointer="debug"/>
223
<term><option>--debuglevel
224
<replaceable>LEVEL</replaceable></option></term>
227
Set the debugging log level.
228
<replaceable>LEVEL</replaceable> is a string, one of
229
<quote><literal>CRITICAL</literal></quote>,
230
<quote><literal>ERROR</literal></quote>,
231
<quote><literal>WARNING</literal></quote>,
232
<quote><literal>INFO</literal></quote>, or
233
<quote><literal>DEBUG</literal></quote>, in order of
234
increasing verbosity. The default level is
235
<quote><literal>WARNING</literal></quote>.
241
<term><option>--priority <replaceable>
242
PRIORITY</replaceable></option></term>
213
<term><literal>--priority <replaceable>
214
PRIORITY</replaceable></literal></term>
244
216
<xi:include href="mandos-options.xml" xpointer="priority"/>
249
<term><option>--servicename
250
<replaceable>NAME</replaceable></option></term>
221
<term><literal>--servicename <replaceable>NAME</replaceable>
252
224
<xi:include href="mandos-options.xml"
253
225
xpointer="servicename"/>
258
<term><option>--configdir
259
<replaceable>DIRECTORY</replaceable></option></term>
230
<term><literal>--configdir <replaceable>DIR</replaceable>
262
234
Directory to search for configuration files. Default is
273
<term><option>--version</option></term>
245
<term><literal>--version</literal></term>
276
248
Prints the program version and exit.
282
<term><option>--no-dbus</option></term>
284
<xi:include href="mandos-options.xml" xpointer="dbus"/>
286
See also <xref linkend="dbus_interface"/>.
292
<term><option>--no-ipv6</option></term>
294
<xi:include href="mandos-options.xml" xpointer="ipv6"/>
299
<term><option>--no-restore</option></term>
301
<xi:include href="mandos-options.xml" xpointer="restore"/>
303
See also <xref linkend="persistent_state"/>.
309
<term><option>--statedir
310
<replaceable>DIRECTORY</replaceable></option></term>
312
<xi:include href="mandos-options.xml" xpointer="statedir"/>
317
<term><option>--socket
318
<replaceable>FD</replaceable></option></term>
320
<xi:include href="mandos-options.xml" xpointer="socket"/>
325
<term><option>--foreground</option></term>
327
<xi:include href="mandos-options.xml"
328
xpointer="foreground"/>
333
<term><option>--no-zeroconf</option></term>
335
<xi:include href="mandos-options.xml" xpointer="zeroconf"/>
342
255
<refsect1 id="overview">
343
256
<title>OVERVIEW</title>
344
257
<xi:include href="overview.xml"/>
346
259
This program is the server part. It is a normal server program
347
260
and will run in a normal system environment, not in an initial
348
<acronym>RAM</acronym> disk environment.
261
RAM disk environment.
352
265
<refsect1 id="protocol">
353
266
<title>NETWORK PROTOCOL</title>
361
274
start a TLS protocol handshake with a slight quirk: the Mandos
362
275
server program acts as a TLS <quote>client</quote> while the
363
276
connecting Mandos client acts as a TLS <quote>server</quote>.
364
The Mandos client must supply a TLS public key, and the key ID
365
of this public key is used by the Mandos server to look up (in a
366
list read from <filename>clients.conf</filename> at start time)
367
which binary blob to give the client. No other authentication
368
or authorization is done by the server.
277
The Mandos client must supply an OpenPGP certificate, and the
278
fingerprint of this certificate is used by the Mandos server to
279
look up (in a list read from <filename>clients.conf</filename>
280
at start time) which binary blob to give the client. No other
281
authentication or authorization is done by the server.
371
284
<title>Mandos Protocol (Version 1)</title><tgroup cols="3"><thead>
407
320
</tbody></tgroup></table>
410
323
<refsect1 id="checking">
411
324
<title>CHECKING</title>
413
326
The server will, by default, continually check that the clients
414
327
are still up. If a client has not been confirmed as being up
415
328
for some time, the client is assumed to be compromised and is no
416
longer eligible to receive the encrypted password. (Manual
417
intervention is required to re-enable a client.) The timeout,
418
extended timeout, checker program, and interval between checks
419
can be configured both globally and per client; see
420
<citerefentry><refentrytitle>mandos-clients.conf</refentrytitle>
329
longer eligible to receive the encrypted password. The timeout,
330
checker program, and interval between checks can be configured
331
both globally and per client; see <citerefentry>
332
<refentrytitle>mandos-clients.conf</refentrytitle>
421
333
<manvolnum>5</manvolnum></citerefentry>.
425
<refsect1 id="approval">
426
<title>APPROVAL</title>
428
The server can be configured to require manual approval for a
429
client before it is sent its secret. The delay to wait for such
430
approval and the default action (approve or deny) can be
431
configured both globally and per client; see <citerefentry>
432
<refentrytitle>mandos-clients.conf</refentrytitle>
433
<manvolnum>5</manvolnum></citerefentry>. By default all clients
434
will be approved immediately without delay.
437
This can be used to deny a client its secret if not manually
438
approved within a specified time. It can also be used to make
439
the server delay before giving a client its secret, allowing
440
optional manual denying of this specific client.
445
337
<refsect1 id="logging">
446
338
<title>LOGGING</title>
448
340
The server will send log message with various severity levels to
449
<filename class="devicefile">/dev/log</filename>. With the
341
<filename>/dev/log</filename>. With the
450
342
<option>--debug</option> option, it will log even more messages,
451
343
and also show them on the console.
455
<refsect1 id="persistent_state">
456
<title>PERSISTENT STATE</title>
458
Client settings, initially read from
459
<filename>clients.conf</filename>, are persistent across
460
restarts, and run-time changes will override settings in
461
<filename>clients.conf</filename>. However, if a setting is
462
<emphasis>changed</emphasis> (or a client added, or removed) in
463
<filename>clients.conf</filename>, this will take precedence.
467
<refsect1 id="dbus_interface">
468
<title>D-BUS INTERFACE</title>
470
The server will by default provide a D-Bus system bus interface.
471
This interface will only be accessible by the root user or a
472
Mandos-specific user, if such a user exists. For documentation
473
of the D-Bus API, see the file <filename>DBUS-API</filename>.
477
347
<refsect1 id="exit_status">
478
348
<title>EXIT STATUS</title>
534
<term><filename>/run/mandos.pid</filename></term>
537
The file containing the process id of the
538
<command>&COMMANDNAME;</command> process started last.
539
<emphasis >Note:</emphasis> If the <filename
540
class="directory">/run</filename> directory does not
541
exist, <filename>/var/run/mandos.pid</filename> will be
548
class="directory">/var/lib/mandos</filename></term>
551
Directory where persistent state will be saved. Change
552
this with the <option>--statedir</option> option. See
553
also the <option>--no-restore</option> option.
558
<term><filename class="devicefile">/dev/log</filename></term>
404
<term><filename>/var/run/mandos/mandos.pid</filename></term>
407
The file containing the process id of
408
<command>&COMMANDNAME;</command>.
413
<term><filename>/dev/log</filename></term>
561
416
The Unix domain socket to where local syslog messages are
584
439
backtrace. This could be considered a feature.
442
Currently, if a client is declared <quote>invalid</quote> due to
443
having timed out, the server does not record this fact onto
444
permanent storage. This has some security implications, see
445
<xref linkend="CLIENTS"/>.
448
There is currently no way of querying the server of the current
449
status of clients, other than analyzing its <systemitem
450
class="service">syslog</systemitem> output.
587
453
There is no fine-grained control over logging and debug output.
589
<xi:include href="bugs.xml"/>
456
Debug mode is conflated with running in the foreground.
459
The console log messages does not show a timestamp.
592
463
<refsect1 id="example">
602
473
<informalexample>
604
475
Run the server in debug mode, read configuration files from
605
the <filename class="directory">~/mandos</filename> directory,
606
and use the Zeroconf service name <quote>Test</quote> to not
607
collide with any other official Mandos server on this host:
476
the <filename>~/mandos</filename> directory, and use the
477
Zeroconf service name <quote>Test</quote> to not collide with
478
any other official Mandos server on this host:
627
498
</informalexample>
630
501
<refsect1 id="security">
631
502
<title>SECURITY</title>
632
<refsect2 id="server">
503
<refsect2 id="SERVER">
633
504
<title>SERVER</title>
635
506
Running this <command>&COMMANDNAME;</command> server program
636
507
should not in itself present any security risk to the host
637
computer running it. The program switches to a non-root user
508
computer running it. The program does not need any special
509
privileges to run, and is designed to run as a non-root user.
641
<refsect2 id="clients">
512
<refsect2 id="CLIENTS">
642
513
<title>CLIENTS</title>
644
515
The server only gives out its stored data to clients which
645
does have the correct key ID of the stored key ID. This is
646
guaranteed by the fact that the client sends its public key in
647
the TLS handshake; this ensures it to be genuine. The server
648
computes the key ID of the key itself and looks up the key ID
649
in its list of clients. The <filename>clients.conf</filename>
516
does have the OpenPGP key of the stored fingerprint. This is
517
guaranteed by the fact that the client sends its OpenPGP
518
public key in the TLS handshake; this ensures it to be
519
genuine. The server computes the fingerprint of the key
520
itself and looks up the fingerprint in its list of
521
clients. The <filename>clients.conf</filename> file (see
651
522
<citerefentry><refentrytitle>mandos-clients.conf</refentrytitle>
652
523
<manvolnum>5</manvolnum></citerefentry>)
653
524
<emphasis>must</emphasis> be made non-readable by anyone
654
except the user starting the server (usually root).
525
except the user running the server.
657
528
As detailed in <xref linkend="checking"/>, the status of all
659
530
compromised if they are gone for too long.
533
If a client is compromised, its downtime should be duly noted
534
by the server which would therefore declare the client
535
invalid. But if the server was ever restarted, it would
536
re-read its client list from its configuration file and again
537
regard all clients therein as valid, and hence eligible to
538
receive their passwords. Therefore, be careful when
539
restarting servers if it is suspected that a client has, in
540
fact, been compromised by parties who may now be running a
541
fake Mandos client with the keys from the non-encrypted
542
initial RAM image of the client host. What should be done in
543
that case (if restarting the server program really is
544
necessary) is to stop the server program, edit the
545
configuration file to omit any suspect clients, and restart
662
549
For more details on client-side security, see
663
<citerefentry><refentrytitle>mandos-client</refentrytitle>
550
<citerefentry><refentrytitle>password-request</refentrytitle>
664
551
<manvolnum>8mandos</manvolnum></citerefentry>.
669
556
<refsect1 id="see_also">
670
557
<title>SEE ALSO</title>
672
<citerefentry><refentrytitle>intro</refentrytitle>
673
<manvolnum>8mandos</manvolnum></citerefentry>,
674
<citerefentry><refentrytitle>mandos-clients.conf</refentrytitle>
675
<manvolnum>5</manvolnum></citerefentry>,
676
<citerefentry><refentrytitle>mandos.conf</refentrytitle>
677
<manvolnum>5</manvolnum></citerefentry>,
678
<citerefentry><refentrytitle>mandos-client</refentrytitle>
679
<manvolnum>8mandos</manvolnum></citerefentry>,
680
<citerefentry><refentrytitle>sh</refentrytitle>
681
<manvolnum>1</manvolnum></citerefentry>
560
<refentrytitle>mandos-clients.conf</refentrytitle>
561
<manvolnum>5</manvolnum></citerefentry>, <citerefentry>
562
<refentrytitle>mandos.conf</refentrytitle>
563
<manvolnum>5</manvolnum></citerefentry>, <citerefentry>
564
<refentrytitle>password-request</refentrytitle>
565
<manvolnum>8mandos</manvolnum></citerefentry>, <citerefentry>
566
<refentrytitle>sh</refentrytitle><manvolnum>1</manvolnum>
773
RFC 7250: <citetitle>Using Raw Public Keys in Transport
774
Layer Security (TLS) and Datagram Transport Layer Security
779
This is implemented by GnuTLS version 3.6.6 and is, if
780
present, used by this server so that raw public keys can be
787
RFC 6091: <citetitle>Using OpenPGP Keys for Transport Layer
788
Security (TLS) Authentication</citetitle>
792
This is implemented by GnuTLS before version 3.6.0 and is,
793
if present, used by this server so that OpenPGP keys can be
660
RFC 5081: <citetitle>Using OpenPGP Keys for Transport Layer
665
This is implemented by GnuTLS and used by this server so
666
that OpenPGP keys can be used.