48
68
<refname><command>&COMMANDNAME;</command></refname>
50
Gives encrypted passwords to authenticated Mandos clients
70
Sends encrypted passwords to authenticated Mandos clients
56
76
<command>&COMMANDNAME;</command>
58
<arg choice="plain"><option>--interface
59
<replaceable>NAME</replaceable></option></arg>
60
<arg choice="plain"><option>-i
61
<replaceable>NAME</replaceable></option></arg>
65
<arg choice="plain"><option>--address
66
<replaceable>ADDRESS</replaceable></option></arg>
67
<arg choice="plain"><option>-a
68
<replaceable>ADDRESS</replaceable></option></arg>
72
<arg choice="plain"><option>--port
73
<replaceable>PORT</replaceable></option></arg>
74
<arg choice="plain"><option>-p
75
<replaceable>PORT</replaceable></option></arg>
78
<arg><option>--priority
79
<replaceable>PRIORITY</replaceable></option></arg>
81
<arg><option>--servicename
82
<replaceable>NAME</replaceable></option></arg>
84
<arg><option>--configdir
85
<replaceable>DIRECTORY</replaceable></option></arg>
87
<arg><option>--debug</option></arg>
89
<arg><option>--no-dbus</option></arg>
91
<arg><option>--no-ipv6</option></arg>
94
<command>&COMMANDNAME;</command>
96
<arg choice="plain"><option>--help</option></arg>
97
<arg choice="plain"><option>-h</option></arg>
101
<command>&COMMANDNAME;</command>
102
<arg choice="plain"><option>--version</option></arg>
105
<command>&COMMANDNAME;</command>
106
<arg choice="plain"><option>--check</option></arg>
77
<arg choice='opt'>--interface<arg choice='plain'>IF</arg></arg>
78
<arg choice='opt'>--address<arg choice='plain'>ADDRESS</arg></arg>
79
<arg choice='opt'>--port<arg choice='plain'>PORT</arg></arg>
80
<arg choice='opt'>--priority<arg choice='plain'>PRIORITY</arg></arg>
81
<arg choice='opt'>--servicename<arg choice='plain'>NAME</arg></arg>
82
<arg choice='opt'>--configdir<arg choice='plain'>DIRECTORY</arg></arg>
83
<arg choice='opt'>--debug</arg>
86
<command>&COMMANDNAME;</command>
87
<arg choice='opt'>-i<arg choice='plain'>IF</arg></arg>
88
<arg choice='opt'>-a<arg choice='plain'>ADDRESS</arg></arg>
89
<arg choice='opt'>-p<arg choice='plain'>PORT</arg></arg>
90
<arg choice='opt'>--priority<arg choice='plain'>PRIORITY</arg></arg>
91
<arg choice='opt'>--servicename<arg choice='plain'>NAME</arg></arg>
92
<arg choice='opt'>--configdir<arg choice='plain'>DIRECTORY</arg></arg>
93
<arg choice='opt'>--debug</arg>
96
<command>&COMMANDNAME;</command>
97
<arg choice='plain'>--help</arg>
100
<command>&COMMANDNAME;</command>
101
<arg choice='plain'>--version</arg>
104
<command>&COMMANDNAME;</command>
105
<arg choice='plain'>--check</arg>
108
107
</refsynopsisdiv>
110
109
<refsect1 id="description">
111
110
<title>DESCRIPTION</title>
113
112
<command>&COMMANDNAME;</command> is a server daemon which
114
113
handles incoming request for passwords for a pre-defined list of
115
114
client host computers. The Mandos server uses Zeroconf to
116
announce itself on the local network, and uses TLS to
117
communicate securely with and to authenticate the clients. The
118
Mandos server uses IPv6 to allow Mandos clients to use IPv6
119
link-local addresses, since the clients will probably not have
120
any other addresses configured (see <xref linkend="overview"/>).
121
Any authenticated client is then given the stored pre-encrypted
122
password for that specific client.
115
announce itself on the local network, and uses GnuTLS to
116
communicate securely with and to authenticate the clients.
117
Mandos uses IPv6 link-local addresses, since the clients are
118
assumed to not have any other addresses configured. Any
119
authenticated client is then given the pre-encrypted password
120
for that specific client.
126
125
<refsect1 id="purpose">
127
126
<title>PURPOSE</title>
129
129
The purpose of this is to enable <emphasis>remote and unattended
130
rebooting</emphasis> of client host computer with an
131
<emphasis>encrypted root file system</emphasis>. See <xref
132
linkend="overview"/> for details.
130
rebooting</emphasis> of any client host computer with an
131
<emphasis>encrypted root file system</emphasis>. The client
132
host computer should start a Mandos client in the initial RAM
133
disk environment, the Mandos client program communicates with
134
this server program to get an encrypted password, which is then
135
decrypted and used to unlock the encrypted root file system.
136
The client host computer can then continue its boot sequence
136
142
<refsect1 id="options">
137
143
<title>OPTIONS</title>
140
<term><option>--help</option></term>
141
<term><option>-h</option></term>
147
<term><literal>-h</literal>, <literal>--help</literal></term>
144
150
Show a help message and exit
150
<term><option>--interface</option>
151
<replaceable>NAME</replaceable></term>
152
<term><option>-i</option>
153
<replaceable>NAME</replaceable></term>
155
<xi:include href="mandos-options.xml" xpointer="interface"/>
160
<term><option>--address
161
<replaceable>ADDRESS</replaceable></option></term>
163
<replaceable>ADDRESS</replaceable></option></term>
165
<xi:include href="mandos-options.xml" xpointer="address"/>
171
<replaceable>PORT</replaceable></option></term>
173
<replaceable>PORT</replaceable></option></term>
175
<xi:include href="mandos-options.xml" xpointer="port"/>
180
<term><option>--check</option></term>
183
Run the server’s self-tests. This includes any unit
156
<term><literal>-i</literal>, <literal>--interface <replaceable>
157
IF</replaceable></literal></term>
160
Only announce the server and listen to requests on network
161
interface <replaceable>IF</replaceable>. Default is to
162
use all available interfaces.
168
<term><literal>-a</literal>, <literal>--address <replaceable>
169
ADDRESS</replaceable></literal></term>
172
If this option is used, the server will only listen to a
173
specific address. This must currently be an IPv6 address;
174
an IPv4 address can be specified using the
175
<quote><literal>::FFFF:192.0.2.3</literal></quote> syntax.
176
Also, if a link-local address is specified, an interface
177
should be set, since a link-local address is only valid on
178
a single interface. By default, the server will listen to
179
all available addresses.
185
<term><literal>-p</literal>, <literal>--port <replaceable>
186
PORT</replaceable></literal></term>
189
If this option is used, the server to bind to that
190
port. By default, the server will listen to an arbitrary
191
port given by the operating system.
197
<term><literal>--check</literal></term>
200
Run the server's self-tests. This includes any unit
190
<term><option>--debug</option></term>
192
<xi:include href="mandos-options.xml" xpointer="debug"/>
197
<term><option>--priority <replaceable>
198
PRIORITY</replaceable></option></term>
200
<xi:include href="mandos-options.xml" xpointer="priority"/>
205
<term><option>--servicename
206
<replaceable>NAME</replaceable></option></term>
208
<xi:include href="mandos-options.xml"
209
xpointer="servicename"/>
214
<term><option>--configdir
215
<replaceable>DIRECTORY</replaceable></option></term>
207
<term><literal>--debug</literal></term>
210
If the server is run in debug mode, it will run in the
211
foreground and print a lot of debugging information. The
212
default is <emphasis>not</emphasis> to run in debug mode.
218
<term><literal>--priority <replaceable>
219
PRIORITY</replaceable></literal></term>
222
GnuTLS priority string for the TLS handshake with the
224
<citerefentry><refentrytitle>gnutls_priority_init
225
</refentrytitle><manvolnum>3</manvolnum></citerefentry>
226
for the syntax. The default is
227
<quote><literal>SECURE256:!CTYPE-X.509:+CTYPE-OPENPGP</literal></quote>.
228
<emphasis>Warning</emphasis>: changing this may make the
229
TLS handshake fail, making communication with clients
236
<term><literal>--servicename <replaceable>NAME</replaceable>
240
Zeroconf service name. The default is
241
<quote><literal>Mandos</literal></quote>. You only need
242
to change this if you for some reason want to run more
243
than one server on the same <emphasis>host</emphasis>,
244
which would not normally be useful. If there are name
245
collisions on the same <emphasis>network</emphasis>, the
246
newer server will automatically rename itself to
247
<quote><literal>Mandos #2</literal></quote>, and so on,
248
therefore this option is not needed in that case.
254
<term><literal>--configdir <replaceable>DIR</replaceable>
218
258
Directory to search for configuration files. Default is
321
334
</tbody></tgroup></table>
324
337
<refsect1 id="checking">
325
338
<title>CHECKING</title>
327
340
The server will, by default, continually check that the clients
328
341
are still up. If a client has not been confirmed as being up
329
342
for some time, the client is assumed to be compromised and is no
330
longer eligible to receive the encrypted password. (Manual
331
intervention is required to re-enable a client.) The timeout,
332
checker program, and interval between checks can be configured
343
longer eligible to receive the encrypted password. The timeout,
344
checker program and interval between checks can be configured
333
345
both globally and per client; see <citerefentry>
346
<refentrytitle>mandos.conf</refentrytitle>
347
<manvolnum>5</manvolnum></citerefentry> and <citerefentry>
334
348
<refentrytitle>mandos-clients.conf</refentrytitle>
335
<manvolnum>5</manvolnum></citerefentry>. A client successfully
336
receiving its password will also be treated as a successful
349
<manvolnum>5</manvolnum></citerefentry>.
341
353
<refsect1 id="logging">
342
354
<title>LOGGING</title>
344
The server will send log message with various severity levels to
345
<filename>/dev/log</filename>. With the
356
The server will send log messaged with various severity levels
357
to <filename>/dev/log</filename>. With the
346
358
<option>--debug</option> option, it will log even more messages,
347
359
and also show them on the console.
351
<refsect1 id="dbus_interface">
352
<title>D-BUS INTERFACE</title>
354
The server will by default provide a D-Bus system bus interface.
355
This interface will only be accessible by the root user or a
356
Mandos-specific user, if such a user exists.
361
363
<refsect1 id="exit_status">
362
364
<title>EXIT STATUS</title>
436
<term><filename>/bin/sh</filename></term>
439
This is used to start the configured checker command for
440
each client. See <citerefentry>
441
<refentrytitle>mandos-clients.conf</refentrytitle>
442
<manvolnum>5</manvolnum></citerefentry> for details.
449
420
<refsect1 id="bugs">
450
421
<title>BUGS</title>
452
423
This server might, on especially fatal errors, emit a Python
453
424
backtrace. This could be considered a feature.
456
Currently, if a client is disabled due to having timed out, the
457
server does not record this fact onto permanent storage. This
458
has some security implications, see <xref linkend="clients"/>.
461
There is currently no way of querying the server of the current
462
status of clients, other than analyzing its <systemitem
463
class="service">syslog</systemitem> output.
466
There is no fine-grained control over logging and debug output.
469
Debug mode is conflated with running in the foreground.
472
The console log messages do not show a time stamp.
475
This server does not check the expire time of clients’ OpenPGP
480
<refsect1 id="example">
481
<title>EXAMPLE</title>
428
<refsect1 id="examples">
429
<title>EXAMPLES</title>
482
430
<informalexample>
484
432
Normal invocation needs no options:
487
<userinput>&COMMANDNAME;</userinput>
435
<userinput>mandos</userinput>
489
437
</informalexample>
490
438
<informalexample>
492
Run the server in debug mode, read configuration files from
493
the <filename>~/mandos</filename> directory, and use the
494
Zeroconf service name <quote>Test</quote> to not collide with
495
any other official Mandos server on this host:
440
Run the server in debug mode and read configuration files from
441
the <filename>~/mandos</filename> directory:
499
445
<!-- do not wrap this line -->
500
<userinput>&COMMANDNAME; --debug --configdir ~/mandos --servicename Test</userinput>
446
<userinput>mandos --debug --configdir ~/mandos --servicename Test</userinput>
503
449
</informalexample>
537
481
itself and looks up the fingerprint in its list of
538
482
clients. The <filename>clients.conf</filename> file (see
539
483
<citerefentry><refentrytitle>mandos-clients.conf</refentrytitle>
540
<manvolnum>5</manvolnum></citerefentry>)
541
<emphasis>must</emphasis> be made non-readable by anyone
542
except the user starting the server (usually root).
545
As detailed in <xref linkend="checking"/>, the status of all
546
client computers will continually be checked and be assumed
547
compromised if they are gone for too long.
550
If a client is compromised, its downtime should be duly noted
551
by the server which would therefore disable the client. But
552
if the server was ever restarted, it would re-read its client
553
list from its configuration file and again regard all clients
554
therein as enabled, and hence eligible to receive their
555
passwords. Therefore, be careful when restarting servers if
556
it is suspected that a client has, in fact, been compromised
557
by parties who may now be running a fake Mandos client with
558
the keys from the non-encrypted initial <acronym>RAM</acronym>
559
image of the client host. What should be done in that case
560
(if restarting the server program really is necessary) is to
561
stop the server program, edit the configuration file to omit
562
any suspect clients, and restart the server program.
484
<manvolnum>5</manvolnum></citerefentry>) must be non-readable
485
by anyone except the user running the server.
565
488
For more details on client-side security, see
566
<citerefentry><refentrytitle>mandos-client</refentrytitle>
489
<citerefentry><refentrytitle>password-request</refentrytitle>
567
490
<manvolnum>8mandos</manvolnum></citerefentry>.
572
495
<refsect1 id="see_also">
573
496
<title>SEE ALSO</title>
576
<refentrytitle>mandos-clients.conf</refentrytitle>
577
<manvolnum>5</manvolnum></citerefentry>, <citerefentry>
578
<refentrytitle>mandos.conf</refentrytitle>
579
<manvolnum>5</manvolnum></citerefentry>, <citerefentry>
580
<refentrytitle>mandos-client</refentrytitle>
581
<manvolnum>8mandos</manvolnum></citerefentry>, <citerefentry>
582
<refentrytitle>sh</refentrytitle><manvolnum>1</manvolnum>
588
<ulink url="http://www.zeroconf.org/">Zeroconf</ulink>
592
Zeroconf is the network protocol standard used by clients
593
for finding this Mandos server on the local network.
599
<ulink url="http://www.avahi.org/">Avahi</ulink>
603
Avahi is the library this server calls to implement
604
Zeroconf service announcements.
610
<ulink url="http://www.gnu.org/software/gnutls/"
615
GnuTLS is the library this server uses to implement TLS for
616
communicating securely with the client, and at the same time
617
confidently get the client’s public OpenPGP key.
623
RFC 4291: <citetitle>IP Version 6 Addressing
624
Architecture</citetitle>
629
<term>Section 2.2: <citetitle>Text Representation of
630
Addresses</citetitle></term>
631
<listitem><para/></listitem>
634
<term>Section 2.5.5.2: <citetitle>IPv4-Mapped IPv6
635
Address</citetitle></term>
636
<listitem><para/></listitem>
639
<term>Section 2.5.6, <citetitle>Link-Local IPv6 Unicast
640
Addresses</citetitle></term>
643
The clients use IPv6 link-local addresses, which are
644
immediately usable since a link-local addresses is
645
automatically assigned to a network interfaces when it
655
RFC 4346: <citetitle>The Transport Layer Security (TLS)
656
Protocol Version 1.1</citetitle>
660
TLS 1.1 is the protocol implemented by GnuTLS.
666
RFC 4880: <citetitle>OpenPGP Message Format</citetitle>
670
The data sent to clients is binary encrypted OpenPGP data.
676
RFC 5081: <citetitle>Using OpenPGP Keys for Transport Layer
681
This is implemented by GnuTLS and used by this server so
682
that OpenPGP keys can be used.
497
<itemizedlist spacing="compact">
499
<citerefentry><refentrytitle>password-request</refentrytitle>
500
<manvolnum>8mandos</manvolnum></citerefentry>
504
<citerefentry><refentrytitle>plugin-runner</refentrytitle>
505
<manvolnum>8mandos</manvolnum></citerefentry>
509
<ulink url="http://www.zeroconf.org/">Zeroconf</ulink>
513
<ulink url="http://www.avahi.org/">Avahi</ulink>
518
url="http://www.gnu.org/software/gnutls/">GnuTLS</ulink>
522
<citation>RFC 4880: <citetitle>OpenPGP Message
523
Format</citetitle></citation>
527
<citation>RFC 5081: <citetitle>Using OpenPGP Keys for
528
Transport Layer Security</citetitle></citation>
532
<citation>RFC 4291: <citetitle>IP Version 6 Addressing
533
Architecture</citetitle>, section 2.5.6, Link-Local IPv6
534
Unicast Addresses</citation>
689
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