68
49
<refname><command>&COMMANDNAME;</command></refname>
70
Sends encrypted passwords to authenticated Mandos clients
51
Gives encrypted passwords to authenticated Mandos clients
76
57
<command>&COMMANDNAME;</command>
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>
59
<arg choice="plain"><option>--interface
60
<replaceable>NAME</replaceable></option></arg>
61
<arg choice="plain"><option>-i
62
<replaceable>NAME</replaceable></option></arg>
66
<arg choice="plain"><option>--address
67
<replaceable>ADDRESS</replaceable></option></arg>
68
<arg choice="plain"><option>-a
69
<replaceable>ADDRESS</replaceable></option></arg>
73
<arg choice="plain"><option>--port
74
<replaceable>PORT</replaceable></option></arg>
75
<arg choice="plain"><option>-p
76
<replaceable>PORT</replaceable></option></arg>
79
<arg><option>--priority
80
<replaceable>PRIORITY</replaceable></option></arg>
82
<arg><option>--servicename
83
<replaceable>NAME</replaceable></option></arg>
85
<arg><option>--configdir
86
<replaceable>DIRECTORY</replaceable></option></arg>
88
<arg><option>--debug</option></arg>
90
<arg><option>--debuglevel
91
<replaceable>LEVEL</replaceable></option></arg>
93
<arg><option>--no-dbus</option></arg>
95
<arg><option>--no-ipv6</option></arg>
98
<command>&COMMANDNAME;</command>
100
<arg choice="plain"><option>--help</option></arg>
101
<arg choice="plain"><option>-h</option></arg>
105
<command>&COMMANDNAME;</command>
106
<arg choice="plain"><option>--version</option></arg>
109
<command>&COMMANDNAME;</command>
110
<arg choice="plain"><option>--check</option></arg>
107
112
</refsynopsisdiv>
109
114
<refsect1 id="description">
110
115
<title>DESCRIPTION</title>
112
117
<command>&COMMANDNAME;</command> is a server daemon which
113
118
handles incoming request for passwords for a pre-defined list of
114
119
client host computers. The Mandos server uses Zeroconf to
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.
120
announce itself on the local network, and uses TLS to
121
communicate securely with and to authenticate the clients. The
122
Mandos server uses IPv6 to allow Mandos clients to use IPv6
123
link-local addresses, since the clients will probably not have
124
any other addresses configured (see <xref linkend="overview"/>).
125
Any authenticated client is then given the stored pre-encrypted
126
password for that specific client.
125
130
<refsect1 id="purpose">
126
131
<title>PURPOSE</title>
129
133
The purpose of this is to enable <emphasis>remote and unattended
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
134
rebooting</emphasis> of client host computer with an
135
<emphasis>encrypted root file system</emphasis>. See <xref
136
linkend="overview"/> for details.
142
140
<refsect1 id="options">
143
141
<title>OPTIONS</title>
147
<term><literal>-h</literal>, <literal>--help</literal></term>
144
<term><option>--help</option></term>
145
<term><option>-h</option></term>
150
148
Show a help message and exit
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
154
<term><option>--interface</option>
155
<replaceable>NAME</replaceable></term>
156
<term><option>-i</option>
157
<replaceable>NAME</replaceable></term>
159
<xi:include href="mandos-options.xml" xpointer="interface"/>
164
<term><option>--address
165
<replaceable>ADDRESS</replaceable></option></term>
167
<replaceable>ADDRESS</replaceable></option></term>
169
<xi:include href="mandos-options.xml" xpointer="address"/>
175
<replaceable>PORT</replaceable></option></term>
177
<replaceable>PORT</replaceable></option></term>
179
<xi:include href="mandos-options.xml" xpointer="port"/>
184
<term><option>--check</option></term>
187
Run the server’s self-tests. This includes any unit
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>
194
<term><option>--debug</option></term>
196
<xi:include href="mandos-options.xml" xpointer="debug"/>
201
<term><option>--debuglevel
202
<replaceable>LEVEL</replaceable></option></term>
205
Set the debugging log level.
206
<replaceable>LEVEL</replaceable> is a string, one of
207
<quote><literal>CRITICAL</literal></quote>,
208
<quote><literal>ERROR</literal></quote>,
209
<quote><literal>WARNING</literal></quote>,
210
<quote><literal>INFO</literal></quote>, or
211
<quote><literal>DEBUG</literal></quote>, in order of
212
increasing verbosity. The default level is
213
<quote><literal>WARNING</literal></quote>.
219
<term><option>--priority <replaceable>
220
PRIORITY</replaceable></option></term>
222
<xi:include href="mandos-options.xml" xpointer="priority"/>
227
<term><option>--servicename
228
<replaceable>NAME</replaceable></option></term>
230
<xi:include href="mandos-options.xml"
231
xpointer="servicename"/>
236
<term><option>--configdir
237
<replaceable>DIRECTORY</replaceable></option></term>
258
240
Directory to search for configuration files. Default is
334
343
</tbody></tgroup></table>
337
346
<refsect1 id="checking">
338
347
<title>CHECKING</title>
340
349
The server will, by default, continually check that the clients
341
350
are still up. If a client has not been confirmed as being up
342
351
for some time, the client is assumed to be compromised and is no
343
longer eligible to receive the encrypted password. The timeout,
344
checker program and interval between checks can be configured
352
longer eligible to receive the encrypted password. (Manual
353
intervention is required to re-enable a client.) The timeout,
354
checker program, and interval between checks can be configured
345
355
both globally and per client; see <citerefentry>
346
<refentrytitle>mandos.conf</refentrytitle>
347
<manvolnum>5</manvolnum></citerefentry> and <citerefentry>
348
<refentrytitle>mandos-clients.conf</refentrytitle>
349
<manvolnum>5</manvolnum></citerefentry>.
356
<refentrytitle>mandos-clients.conf</refentrytitle>
357
<manvolnum>5</manvolnum></citerefentry>. A client successfully
358
receiving its password will also be treated as a successful
363
<refsect1 id="approval">
364
<title>APPROVAL</title>
366
The server can be configured to require manual approval for a
367
client before it is sent its secret. The delay to wait for such
368
approval and the default action (approve or deny) can be
369
configured both globally and per client; see <citerefentry>
370
<refentrytitle>mandos-clients.conf</refentrytitle>
371
<manvolnum>5</manvolnum></citerefentry>. By default all clients
372
will be approved immediately without delay.
375
This can be used to deny a client its secret if not manually
376
approved within a specified time. It can also be used to make
377
the server delay before giving a client its secret, allowing
378
optional manual denying of this specific client.
353
383
<refsect1 id="logging">
354
384
<title>LOGGING</title>
356
The server will send log messaged with various severity levels
357
to <filename>/dev/log</filename>. With the
386
The server will send log message with various severity levels to
387
<filename>/dev/log</filename>. With the
358
388
<option>--debug</option> option, it will log even more messages,
359
389
and also show them on the console.
393
<refsect1 id="dbus_interface">
394
<title>D-BUS INTERFACE</title>
396
The server will by default provide a D-Bus system bus interface.
397
This interface will only be accessible by the root user or a
398
Mandos-specific user, if such a user exists. For documentation
399
of the D-Bus API, see the file <filename>DBUS-API</filename>.
363
403
<refsect1 id="exit_status">
364
404
<title>EXIT STATUS</title>
481
574
itself and looks up the fingerprint in its list of
482
575
clients. The <filename>clients.conf</filename> file (see
483
576
<citerefentry><refentrytitle>mandos-clients.conf</refentrytitle>
484
<manvolnum>5</manvolnum></citerefentry>) must be non-readable
485
by anyone except the user running the server.
577
<manvolnum>5</manvolnum></citerefentry>)
578
<emphasis>must</emphasis> be made non-readable by anyone
579
except the user starting the server (usually root).
582
As detailed in <xref linkend="checking"/>, the status of all
583
client computers will continually be checked and be assumed
584
compromised if they are gone for too long.
587
If a client is compromised, its downtime should be duly noted
588
by the server which would therefore disable the client. But
589
if the server was ever restarted, it would re-read its client
590
list from its configuration file and again regard all clients
591
therein as enabled, and hence eligible to receive their
592
passwords. Therefore, be careful when restarting servers if
593
it is suspected that a client has, in fact, been compromised
594
by parties who may now be running a fake Mandos client with
595
the keys from the non-encrypted initial <acronym>RAM</acronym>
596
image of the client host. What should be done in that case
597
(if restarting the server program really is necessary) is to
598
stop the server program, edit the configuration file to omit
599
any suspect clients, and restart the server program.
488
602
For more details on client-side security, see
489
<citerefentry><refentrytitle>password-request</refentrytitle>
603
<citerefentry><refentrytitle>mandos-client</refentrytitle>
490
604
<manvolnum>8mandos</manvolnum></citerefentry>.
495
609
<refsect1 id="see_also">
496
610
<title>SEE ALSO</title>
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>
613
<refentrytitle>mandos-clients.conf</refentrytitle>
614
<manvolnum>5</manvolnum></citerefentry>, <citerefentry>
615
<refentrytitle>mandos.conf</refentrytitle>
616
<manvolnum>5</manvolnum></citerefentry>, <citerefentry>
617
<refentrytitle>mandos-client</refentrytitle>
618
<manvolnum>8mandos</manvolnum></citerefentry>, <citerefentry>
619
<refentrytitle>sh</refentrytitle><manvolnum>1</manvolnum>
625
<ulink url="http://www.zeroconf.org/">Zeroconf</ulink>
629
Zeroconf is the network protocol standard used by clients
630
for finding this Mandos server on the local network.
636
<ulink url="http://www.avahi.org/">Avahi</ulink>
640
Avahi is the library this server calls to implement
641
Zeroconf service announcements.
647
<ulink url="http://www.gnu.org/software/gnutls/"
652
GnuTLS is the library this server uses to implement TLS for
653
communicating securely with the client, and at the same time
654
confidently get the client’s public OpenPGP key.
660
RFC 4291: <citetitle>IP Version 6 Addressing
661
Architecture</citetitle>
666
<term>Section 2.2: <citetitle>Text Representation of
667
Addresses</citetitle></term>
668
<listitem><para/></listitem>
671
<term>Section 2.5.5.2: <citetitle>IPv4-Mapped IPv6
672
Address</citetitle></term>
673
<listitem><para/></listitem>
676
<term>Section 2.5.6, <citetitle>Link-Local IPv6 Unicast
677
Addresses</citetitle></term>
680
The clients use IPv6 link-local addresses, which are
681
immediately usable since a link-local addresses is
682
automatically assigned to a network interfaces when it
692
RFC 4346: <citetitle>The Transport Layer Security (TLS)
693
Protocol Version 1.1</citetitle>
697
TLS 1.1 is the protocol implemented by GnuTLS.
703
RFC 4880: <citetitle>OpenPGP Message Format</citetitle>
707
The data sent to clients is binary encrypted OpenPGP data.
713
RFC 5081: <citetitle>Using OpenPGP Keys for Transport Layer
718
This is implemented by GnuTLS and used by this server so
719
that OpenPGP keys can be used.
726
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