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
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
client host computers. For an introduction, see
121
<citerefentry><refentrytitle>intro</refentrytitle>
122
<manvolnum>8mandos</manvolnum></citerefentry>. The Mandos server
123
uses Zeroconf to announce itself on the local network, and uses
124
TLS to communicate securely with and to authenticate the
125
clients. The Mandos server uses IPv6 to allow Mandos clients to
126
use IPv6 link-local addresses, since the clients will probably
127
not have any other addresses configured (see <xref
128
linkend="overview"/>). Any authenticated client is then given
129
the stored pre-encrypted password for that specific client.
125
133
<refsect1 id="purpose">
126
134
<title>PURPOSE</title>
129
136
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
137
rebooting</emphasis> of client host computer with an
138
<emphasis>encrypted root file system</emphasis>. See <xref
139
linkend="overview"/> for details.
142
143
<refsect1 id="options">
143
144
<title>OPTIONS</title>
147
<term><literal>-h</literal>, <literal>--help</literal></term>
147
<term><option>--help</option></term>
148
<term><option>-h</option></term>
150
151
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
157
<term><option>--interface</option>
158
<replaceable>NAME</replaceable></term>
159
<term><option>-i</option>
160
<replaceable>NAME</replaceable></term>
162
<xi:include href="mandos-options.xml" xpointer="interface"/>
167
<term><option>--address
168
<replaceable>ADDRESS</replaceable></option></term>
170
<replaceable>ADDRESS</replaceable></option></term>
172
<xi:include href="mandos-options.xml" xpointer="address"/>
178
<replaceable>PORT</replaceable></option></term>
180
<replaceable>PORT</replaceable></option></term>
182
<xi:include href="mandos-options.xml" xpointer="port"/>
187
<term><option>--check</option></term>
190
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>
197
<term><option>--debug</option></term>
199
<xi:include href="mandos-options.xml" xpointer="debug"/>
204
<term><option>--debuglevel
205
<replaceable>LEVEL</replaceable></option></term>
208
Set the debugging log level.
209
<replaceable>LEVEL</replaceable> is a string, one of
210
<quote><literal>CRITICAL</literal></quote>,
211
<quote><literal>ERROR</literal></quote>,
212
<quote><literal>WARNING</literal></quote>,
213
<quote><literal>INFO</literal></quote>, or
214
<quote><literal>DEBUG</literal></quote>, in order of
215
increasing verbosity. The default level is
216
<quote><literal>WARNING</literal></quote>.
222
<term><option>--priority <replaceable>
223
PRIORITY</replaceable></option></term>
225
<xi:include href="mandos-options.xml" xpointer="priority"/>
230
<term><option>--servicename
231
<replaceable>NAME</replaceable></option></term>
233
<xi:include href="mandos-options.xml"
234
xpointer="servicename"/>
239
<term><option>--configdir
240
<replaceable>DIRECTORY</replaceable></option></term>
258
243
Directory to search for configuration files. Default is
334
346
</tbody></tgroup></table>
337
349
<refsect1 id="checking">
338
350
<title>CHECKING</title>
340
352
The server will, by default, continually check that the clients
341
353
are still up. If a client has not been confirmed as being up
342
354
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
345
both globally and per client; see <citerefentry>
346
<refentrytitle>mandos.conf</refentrytitle>
347
<manvolnum>5</manvolnum></citerefentry> and <citerefentry>
355
longer eligible to receive the encrypted password. (Manual
356
intervention is required to re-enable a client.) The timeout,
357
extended timeout, checker program, and interval between checks
358
can be configured both globally and per client; see
359
<citerefentry><refentrytitle>mandos-clients.conf</refentrytitle>
360
<manvolnum>5</manvolnum></citerefentry>. A client successfully
361
receiving its password will also be treated as a successful
366
<refsect1 id="approval">
367
<title>APPROVAL</title>
369
The server can be configured to require manual approval for a
370
client before it is sent its secret. The delay to wait for such
371
approval and the default action (approve or deny) can be
372
configured both globally and per client; see <citerefentry>
348
373
<refentrytitle>mandos-clients.conf</refentrytitle>
349
<manvolnum>5</manvolnum></citerefentry>.
374
<manvolnum>5</manvolnum></citerefentry>. By default all clients
375
will be approved immediately without delay.
378
This can be used to deny a client its secret if not manually
379
approved within a specified time. It can also be used to make
380
the server delay before giving a client its secret, allowing
381
optional manual denying of this specific client.
353
386
<refsect1 id="logging">
354
387
<title>LOGGING</title>
356
The server will send log messaged with various severity levels
357
to <filename>/dev/log</filename>. With the
389
The server will send log message with various severity levels to
390
<filename>/dev/log</filename>. With the
358
391
<option>--debug</option> option, it will log even more messages,
359
392
and also show them on the console.
396
<refsect1 id="dbus_interface">
397
<title>D-BUS INTERFACE</title>
399
The server will by default provide a D-Bus system bus interface.
400
This interface will only be accessible by the root user or a
401
Mandos-specific user, if such a user exists. For documentation
402
of the D-Bus API, see the file <filename>DBUS-API</filename>.
363
406
<refsect1 id="exit_status">
364
407
<title>EXIT STATUS</title>
481
577
itself and looks up the fingerprint in its list of
482
578
clients. The <filename>clients.conf</filename> file (see
483
579
<citerefentry><refentrytitle>mandos-clients.conf</refentrytitle>
484
<manvolnum>5</manvolnum></citerefentry>) must be non-readable
485
by anyone except the user running the server.
580
<manvolnum>5</manvolnum></citerefentry>)
581
<emphasis>must</emphasis> be made non-readable by anyone
582
except the user starting the server (usually root).
585
As detailed in <xref linkend="checking"/>, the status of all
586
client computers will continually be checked and be assumed
587
compromised if they are gone for too long.
590
If a client is compromised, its downtime should be duly noted
591
by the server which would therefore disable the client. But
592
if the server was ever restarted, it would re-read its client
593
list from its configuration file and again regard all clients
594
therein as enabled, and hence eligible to receive their
595
passwords. Therefore, be careful when restarting servers if
596
it is suspected that a client has, in fact, been compromised
597
by parties who may now be running a fake Mandos client with
598
the keys from the non-encrypted initial <acronym>RAM</acronym>
599
image of the client host. What should be done in that case
600
(if restarting the server program really is necessary) is to
601
stop the server program, edit the configuration file to omit
602
any suspect clients, and restart the server program.
488
605
For more details on client-side security, see
489
<citerefentry><refentrytitle>password-request</refentrytitle>
606
<citerefentry><refentrytitle>mandos-client</refentrytitle>
490
607
<manvolnum>8mandos</manvolnum></citerefentry>.
495
612
<refsect1 id="see_also">
496
613
<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>
615
<citerefentry><refentrytitle>intro</refentrytitle>
616
<manvolnum>8mandos</manvolnum></citerefentry>,
617
<citerefentry><refentrytitle>mandos-clients.conf</refentrytitle>
618
<manvolnum>5</manvolnum></citerefentry>,
619
<citerefentry><refentrytitle>mandos.conf</refentrytitle>
620
<manvolnum>5</manvolnum></citerefentry>,
621
<citerefentry><refentrytitle>mandos-client</refentrytitle>
622
<manvolnum>8mandos</manvolnum></citerefentry>,
623
<citerefentry><refentrytitle>sh</refentrytitle>
624
<manvolnum>1</manvolnum></citerefentry>
629
<ulink url="http://www.zeroconf.org/">Zeroconf</ulink>
633
Zeroconf is the network protocol standard used by clients
634
for finding this Mandos server on the local network.
640
<ulink url="http://www.avahi.org/">Avahi</ulink>
644
Avahi is the library this server calls to implement
645
Zeroconf service announcements.
651
<ulink url="http://www.gnu.org/software/gnutls/"
656
GnuTLS is the library this server uses to implement TLS for
657
communicating securely with the client, and at the same time
658
confidently get the client’s public OpenPGP key.
664
RFC 4291: <citetitle>IP Version 6 Addressing
665
Architecture</citetitle>
670
<term>Section 2.2: <citetitle>Text Representation of
671
Addresses</citetitle></term>
672
<listitem><para/></listitem>
675
<term>Section 2.5.5.2: <citetitle>IPv4-Mapped IPv6
676
Address</citetitle></term>
677
<listitem><para/></listitem>
680
<term>Section 2.5.6, <citetitle>Link-Local IPv6 Unicast
681
Addresses</citetitle></term>
684
The clients use IPv6 link-local addresses, which are
685
immediately usable since a link-local addresses is
686
automatically assigned to a network interfaces when it
696
RFC 4346: <citetitle>The Transport Layer Security (TLS)
697
Protocol Version 1.1</citetitle>
701
TLS 1.1 is the protocol implemented by GnuTLS.
707
RFC 4880: <citetitle>OpenPGP Message Format</citetitle>
711
The data sent to clients is binary encrypted OpenPGP data.
717
RFC 5081: <citetitle>Using OpenPGP Keys for Transport Layer
722
This is implemented by GnuTLS and used by this server so
723
that OpenPGP keys can be used.
730
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