68
50
<refname><command>&COMMANDNAME;</command></refname>
70
Sends encrypted passwords to authenticated Mandos clients
52
Gives encrypted passwords to authenticated Mandos clients
76
58
<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>
60
<arg choice="plain"><option>--interface
61
<replaceable>NAME</replaceable></option></arg>
62
<arg choice="plain"><option>-i
63
<replaceable>NAME</replaceable></option></arg>
67
<arg choice="plain"><option>--address
68
<replaceable>ADDRESS</replaceable></option></arg>
69
<arg choice="plain"><option>-a
70
<replaceable>ADDRESS</replaceable></option></arg>
74
<arg choice="plain"><option>--port
75
<replaceable>PORT</replaceable></option></arg>
76
<arg choice="plain"><option>-p
77
<replaceable>PORT</replaceable></option></arg>
80
<arg><option>--priority
81
<replaceable>PRIORITY</replaceable></option></arg>
83
<arg><option>--servicename
84
<replaceable>NAME</replaceable></option></arg>
86
<arg><option>--configdir
87
<replaceable>DIRECTORY</replaceable></option></arg>
89
<arg><option>--debug</option></arg>
91
<arg><option>--debuglevel
92
<replaceable>LEVEL</replaceable></option></arg>
94
<arg><option>--no-dbus</option></arg>
96
<arg><option>--no-ipv6</option></arg>
99
<command>&COMMANDNAME;</command>
101
<arg choice="plain"><option>--help</option></arg>
102
<arg choice="plain"><option>-h</option></arg>
106
<command>&COMMANDNAME;</command>
107
<arg choice="plain"><option>--version</option></arg>
110
<command>&COMMANDNAME;</command>
111
<arg choice="plain"><option>--check</option></arg>
107
113
</refsynopsisdiv>
109
115
<refsect1 id="description">
110
116
<title>DESCRIPTION</title>
112
118
<command>&COMMANDNAME;</command> is a server daemon which
113
119
handles incoming request for passwords for a pre-defined list of
114
120
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.
121
announce itself on the local network, and uses TLS to
122
communicate securely with and to authenticate the clients. The
123
Mandos server uses IPv6 to allow Mandos clients to use IPv6
124
link-local addresses, since the clients will probably not have
125
any other addresses configured (see <xref linkend="overview"/>).
126
Any authenticated client is then given the stored pre-encrypted
127
password for that specific client.
125
131
<refsect1 id="purpose">
126
132
<title>PURPOSE</title>
129
134
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
135
rebooting</emphasis> of client host computer with an
136
<emphasis>encrypted root file system</emphasis>. See <xref
137
linkend="overview"/> for details.
142
141
<refsect1 id="options">
143
142
<title>OPTIONS</title>
147
<term><literal>-h</literal>, <literal>--help</literal></term>
145
<term><option>--help</option></term>
146
<term><option>-h</option></term>
150
149
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
155
<term><option>--interface</option>
156
<replaceable>NAME</replaceable></term>
157
<term><option>-i</option>
158
<replaceable>NAME</replaceable></term>
160
<xi:include href="mandos-options.xml" xpointer="interface"/>
165
<term><option>--address
166
<replaceable>ADDRESS</replaceable></option></term>
168
<replaceable>ADDRESS</replaceable></option></term>
170
<xi:include href="mandos-options.xml" xpointer="address"/>
176
<replaceable>PORT</replaceable></option></term>
178
<replaceable>PORT</replaceable></option></term>
180
<xi:include href="mandos-options.xml" xpointer="port"/>
185
<term><option>--check</option></term>
188
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>
195
<term><option>--debug</option></term>
197
<xi:include href="mandos-options.xml" xpointer="debug"/>
202
<term><option>--debuglevel
203
<replaceable>LEVEL</replaceable></option></term>
206
Set the debugging log level.
207
<replaceable>LEVEL</replaceable> is a string, one of
208
<quote><literal>CRITICAL</literal></quote>,
209
<quote><literal>ERROR</literal></quote>,
210
<quote><literal>WARNING</literal></quote>,
211
<quote><literal>INFO</literal></quote>, or
212
<quote><literal>DEBUG</literal></quote>, in order of
213
increasing verbosity. The default level is
214
<quote><literal>WARNING</literal></quote>.
220
<term><option>--priority <replaceable>
221
PRIORITY</replaceable></option></term>
223
<xi:include href="mandos-options.xml" xpointer="priority"/>
228
<term><option>--servicename
229
<replaceable>NAME</replaceable></option></term>
231
<xi:include href="mandos-options.xml"
232
xpointer="servicename"/>
237
<term><option>--configdir
238
<replaceable>DIRECTORY</replaceable></option></term>
258
241
Directory to search for configuration files. Default is
334
344
</tbody></tgroup></table>
337
347
<refsect1 id="checking">
338
348
<title>CHECKING</title>
340
350
The server will, by default, continually check that the clients
341
351
are still up. If a client has not been confirmed as being up
342
352
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
353
longer eligible to receive the encrypted password. (Manual
354
intervention is required to re-enable a client.) The timeout,
355
checker program, and interval between checks can be configured
345
356
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>.
357
<refentrytitle>mandos-clients.conf</refentrytitle>
358
<manvolnum>5</manvolnum></citerefentry>. A client successfully
359
receiving its password will also be treated as a successful
364
<refsect1 id="approval">
365
<title>APPROVAL</title>
367
The server can be configured to require manual approval for a
368
client before it is sent its secret. The delay to wait for such
369
approval and the default action (approve or deny) can be
370
configured both globally and per client; see <citerefentry>
371
<refentrytitle>mandos-clients.conf</refentrytitle>
372
<manvolnum>5</manvolnum></citerefentry>. By default all clients
373
will be approved immediately without delay.
376
This can be used to deny a client its secret if not manually
377
approved within a specified time. It can also be used to make
378
the server delay before giving a client its secret, allowing
379
optional manual denying of this specific client.
353
384
<refsect1 id="logging">
354
385
<title>LOGGING</title>
356
The server will send log messaged with various severity levels
357
to <filename>/dev/log</filename>. With the
387
The server will send log message with various severity levels to
388
<filename>/dev/log</filename>. With the
358
389
<option>--debug</option> option, it will log even more messages,
359
390
and also show them on the console.
394
<refsect1 id="dbus_interface">
395
<title>D-BUS INTERFACE</title>
397
The server will by default provide a D-Bus system bus interface.
398
This interface will only be accessible by the root user or a
399
Mandos-specific user, if such a user exists. For documentation
400
of the D-Bus API, see the file <filename>DBUS-API</filename>.
363
404
<refsect1 id="exit_status">
364
405
<title>EXIT STATUS</title>
481
575
itself and looks up the fingerprint in its list of
482
576
clients. The <filename>clients.conf</filename> file (see
483
577
<citerefentry><refentrytitle>mandos-clients.conf</refentrytitle>
484
<manvolnum>5</manvolnum></citerefentry>) must be non-readable
485
by anyone except the user running the server.
578
<manvolnum>5</manvolnum></citerefentry>)
579
<emphasis>must</emphasis> be made non-readable by anyone
580
except the user starting the server (usually root).
583
As detailed in <xref linkend="checking"/>, the status of all
584
client computers will continually be checked and be assumed
585
compromised if they are gone for too long.
588
If a client is compromised, its downtime should be duly noted
589
by the server which would therefore disable the client. But
590
if the server was ever restarted, it would re-read its client
591
list from its configuration file and again regard all clients
592
therein as enabled, and hence eligible to receive their
593
passwords. Therefore, be careful when restarting servers if
594
it is suspected that a client has, in fact, been compromised
595
by parties who may now be running a fake Mandos client with
596
the keys from the non-encrypted initial <acronym>RAM</acronym>
597
image of the client host. What should be done in that case
598
(if restarting the server program really is necessary) is to
599
stop the server program, edit the configuration file to omit
600
any suspect clients, and restart the server program.
488
603
For more details on client-side security, see
489
<citerefentry><refentrytitle>password-request</refentrytitle>
604
<citerefentry><refentrytitle>mandos-client</refentrytitle>
490
605
<manvolnum>8mandos</manvolnum></citerefentry>.
495
610
<refsect1 id="see_also">
496
611
<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>
614
<refentrytitle>mandos-clients.conf</refentrytitle>
615
<manvolnum>5</manvolnum></citerefentry>, <citerefentry>
616
<refentrytitle>mandos.conf</refentrytitle>
617
<manvolnum>5</manvolnum></citerefentry>, <citerefentry>
618
<refentrytitle>mandos-client</refentrytitle>
619
<manvolnum>8mandos</manvolnum></citerefentry>, <citerefentry>
620
<refentrytitle>sh</refentrytitle><manvolnum>1</manvolnum>
626
<ulink url="http://www.zeroconf.org/">Zeroconf</ulink>
630
Zeroconf is the network protocol standard used by clients
631
for finding this Mandos server on the local network.
637
<ulink url="http://www.avahi.org/">Avahi</ulink>
641
Avahi is the library this server calls to implement
642
Zeroconf service announcements.
648
<ulink url="http://www.gnu.org/software/gnutls/"
653
GnuTLS is the library this server uses to implement TLS for
654
communicating securely with the client, and at the same time
655
confidently get the client’s public OpenPGP key.
661
RFC 4291: <citetitle>IP Version 6 Addressing
662
Architecture</citetitle>
667
<term>Section 2.2: <citetitle>Text Representation of
668
Addresses</citetitle></term>
669
<listitem><para/></listitem>
672
<term>Section 2.5.5.2: <citetitle>IPv4-Mapped IPv6
673
Address</citetitle></term>
674
<listitem><para/></listitem>
677
<term>Section 2.5.6, <citetitle>Link-Local IPv6 Unicast
678
Addresses</citetitle></term>
681
The clients use IPv6 link-local addresses, which are
682
immediately usable since a link-local addresses is
683
automatically assigned to a network interfaces when it
693
RFC 4346: <citetitle>The Transport Layer Security (TLS)
694
Protocol Version 1.1</citetitle>
698
TLS 1.1 is the protocol implemented by GnuTLS.
704
RFC 4880: <citetitle>OpenPGP Message Format</citetitle>
708
The data sent to clients is binary encrypted OpenPGP data.
714
RFC 5081: <citetitle>Using OpenPGP Keys for Transport Layer
719
This is implemented by GnuTLS and used by this server so
720
that OpenPGP keys can be used.
727
<!-- Local Variables: -->
728
<!-- time-stamp-start: "<!ENTITY TIMESTAMP [\"']" -->
729
<!-- time-stamp-end: "[\"']>" -->
730
<!-- time-stamp-format: "%:y-%02m-%02d" -->