51
67
<refname><command>&COMMANDNAME;</command></refname>
53
Gives encrypted passwords to authenticated Mandos clients
69
Sends encrypted passwords to authenticated mandos clients
59
75
<command>&COMMANDNAME;</command>
61
<arg choice="plain"><option>--interface
62
<replaceable>NAME</replaceable></option></arg>
63
<arg choice="plain"><option>-i
64
<replaceable>NAME</replaceable></option></arg>
68
<arg choice="plain"><option>--address
69
<replaceable>ADDRESS</replaceable></option></arg>
70
<arg choice="plain"><option>-a
71
<replaceable>ADDRESS</replaceable></option></arg>
75
<arg choice="plain"><option>--port
76
<replaceable>PORT</replaceable></option></arg>
77
<arg choice="plain"><option>-p
78
<replaceable>PORT</replaceable></option></arg>
81
<arg><option>--priority
82
<replaceable>PRIORITY</replaceable></option></arg>
84
<arg><option>--servicename
85
<replaceable>NAME</replaceable></option></arg>
87
<arg><option>--configdir
88
<replaceable>DIRECTORY</replaceable></option></arg>
90
<arg><option>--debug</option></arg>
92
<arg><option>--debuglevel
93
<replaceable>LEVEL</replaceable></option></arg>
95
<arg><option>--no-dbus</option></arg>
97
<arg><option>--no-ipv6</option></arg>
99
<arg><option>--no-restore</option></arg>
101
<arg><option>--statedir
102
<replaceable>DIRECTORY</replaceable></option></arg>
104
<arg><option>--socket
105
<replaceable>FD</replaceable></option></arg>
108
<command>&COMMANDNAME;</command>
110
<arg choice="plain"><option>--help</option></arg>
111
<arg choice="plain"><option>-h</option></arg>
115
<command>&COMMANDNAME;</command>
116
<arg choice="plain"><option>--version</option></arg>
119
<command>&COMMANDNAME;</command>
120
<arg choice="plain"><option>--check</option></arg>
76
<arg choice='opt'>--interface<arg choice='plain'>IF</arg></arg>
77
<arg choice='opt'>--address<arg choice='plain'>ADDRESS</arg></arg>
78
<arg choice='opt'>--port<arg choice='plain'>PORT</arg></arg>
79
<arg choice='opt'>--priority<arg choice='plain'>PRIORITY</arg></arg>
80
<arg choice='opt'>--servicename<arg choice='plain'>NAME</arg></arg>
81
<arg choice='opt'>--configdir<arg choice='plain'>DIRECTORY</arg></arg>
82
<arg choice='opt'>--debug</arg>
85
<command>&COMMANDNAME;</command>
86
<arg choice='plain'>--help</arg>
89
<command>&COMMANDNAME;</command>
90
<arg choice='plain'>--check</arg>
93
<command>&COMMANDNAME;</command>
94
<arg choice='plain'>--version</arg>
124
98
<refsect1 id="description">
125
99
<title>DESCRIPTION</title>
127
<command>&COMMANDNAME;</command> is a server daemon which
128
handles incoming request for passwords for a pre-defined list of
129
client host computers. For an introduction, see
130
<citerefentry><refentrytitle>intro</refentrytitle>
131
<manvolnum>8mandos</manvolnum></citerefentry>. The Mandos server
132
uses Zeroconf to announce itself on the local network, and uses
133
TLS to communicate securely with and to authenticate the
134
clients. The Mandos server uses IPv6 to allow Mandos clients to
135
use IPv6 link-local addresses, since the clients will probably
136
not have any other addresses configured (see <xref
137
linkend="overview"/>). Any authenticated client is then given
138
the stored pre-encrypted password for that specific client.
142
<refsect1 id="purpose">
143
<title>PURPOSE</title>
145
The purpose of this is to enable <emphasis>remote and unattended
146
rebooting</emphasis> of client host computer with an
147
<emphasis>encrypted root file system</emphasis>. See <xref
148
linkend="overview"/> for details.
152
<refsect1 id="options">
153
<title>OPTIONS</title>
156
<term><option>--help</option></term>
157
<term><option>-h</option></term>
160
Show a help message and exit
166
<term><option>--interface</option>
167
<replaceable>NAME</replaceable></term>
168
<term><option>-i</option>
169
<replaceable>NAME</replaceable></term>
171
<xi:include href="mandos-options.xml" xpointer="interface"/>
176
<term><option>--address
177
<replaceable>ADDRESS</replaceable></option></term>
179
<replaceable>ADDRESS</replaceable></option></term>
181
<xi:include href="mandos-options.xml" xpointer="address"/>
187
<replaceable>PORT</replaceable></option></term>
189
<replaceable>PORT</replaceable></option></term>
191
<xi:include href="mandos-options.xml" xpointer="port"/>
196
<term><option>--check</option></term>
199
Run the server’s self-tests. This includes any unit
206
<term><option>--debug</option></term>
208
<xi:include href="mandos-options.xml" xpointer="debug"/>
213
<term><option>--debuglevel
214
<replaceable>LEVEL</replaceable></option></term>
217
Set the debugging log level.
218
<replaceable>LEVEL</replaceable> is a string, one of
219
<quote><literal>CRITICAL</literal></quote>,
220
<quote><literal>ERROR</literal></quote>,
221
<quote><literal>WARNING</literal></quote>,
222
<quote><literal>INFO</literal></quote>, or
223
<quote><literal>DEBUG</literal></quote>, in order of
224
increasing verbosity. The default level is
225
<quote><literal>WARNING</literal></quote>.
231
<term><option>--priority <replaceable>
232
PRIORITY</replaceable></option></term>
234
<xi:include href="mandos-options.xml" xpointer="priority"/>
239
<term><option>--servicename
240
<replaceable>NAME</replaceable></option></term>
242
<xi:include href="mandos-options.xml"
243
xpointer="servicename"/>
248
<term><option>--configdir
249
<replaceable>DIRECTORY</replaceable></option></term>
252
Directory to search for configuration files. Default is
253
<quote><literal>/etc/mandos</literal></quote>. See
254
<citerefentry><refentrytitle>mandos.conf</refentrytitle>
255
<manvolnum>5</manvolnum></citerefentry> and <citerefentry>
256
<refentrytitle>mandos-clients.conf</refentrytitle>
257
<manvolnum>5</manvolnum></citerefentry>.
263
<term><option>--version</option></term>
266
Prints the program version and exit.
272
<term><option>--no-dbus</option></term>
274
<xi:include href="mandos-options.xml" xpointer="dbus"/>
276
See also <xref linkend="dbus_interface"/>.
282
<term><option>--no-ipv6</option></term>
284
<xi:include href="mandos-options.xml" xpointer="ipv6"/>
289
<term><option>--no-restore</option></term>
291
<xi:include href="mandos-options.xml" xpointer="restore"/>
293
See also <xref linkend="persistent_state"/>.
299
<term><option>--statedir
300
<replaceable>DIRECTORY</replaceable></option></term>
302
<xi:include href="mandos-options.xml" xpointer="statedir"/>
307
<term><option>--socket
308
<replaceable>FD</replaceable></option></term>
310
<xi:include href="mandos-options.xml" xpointer="socket"/>
317
<refsect1 id="overview">
318
<title>OVERVIEW</title>
319
<xi:include href="overview.xml"/>
321
This program is the server part. It is a normal server program
322
and will run in a normal system environment, not in an initial
323
<acronym>RAM</acronym> disk environment.
327
<refsect1 id="protocol">
328
<title>NETWORK PROTOCOL</title>
330
The Mandos server announces itself as a Zeroconf service of type
331
<quote><literal>_mandos._tcp</literal></quote>. The Mandos
332
client connects to the announced address and port, and sends a
333
line of text where the first whitespace-separated field is the
334
protocol version, which currently is
335
<quote><literal>1</literal></quote>. The client and server then
336
start a TLS protocol handshake with a slight quirk: the Mandos
337
server program acts as a TLS <quote>client</quote> while the
338
connecting Mandos client acts as a TLS <quote>server</quote>.
339
The Mandos client must supply an OpenPGP certificate, and the
340
fingerprint of this certificate is used by the Mandos server to
341
look up (in a list read from <filename>clients.conf</filename>
342
at start time) which binary blob to give the client. No other
343
authentication or authorization is done by the server.
346
<title>Mandos Protocol (Version 1)</title><tgroup cols="3"><thead>
348
<entry>Mandos Client</entry>
349
<entry>Direction</entry>
350
<entry>Mandos Server</entry>
354
<entry>Connect</entry>
355
<entry>-><!-- → --></entry>
358
<entry><quote><literal>1\r\n</literal></quote></entry>
359
<entry>-><!-- → --></entry>
362
<entry>TLS handshake <emphasis>as TLS <quote>server</quote>
364
<entry><-><!-- ⟷ --></entry>
365
<entry>TLS handshake <emphasis>as TLS <quote>client</quote>
369
<entry>OpenPGP public key (part of TLS handshake)</entry>
370
<entry>-><!-- → --></entry>
374
<entry><-<!-- ← --></entry>
375
<entry>Binary blob (client will assume OpenPGP data)</entry>
379
<entry><-<!-- ← --></entry>
382
</tbody></tgroup></table>
385
<refsect1 id="checking">
386
<title>CHECKING</title>
388
The server will, by default, continually check that the clients
389
are still up. If a client has not been confirmed as being up
390
for some time, the client is assumed to be compromised and is no
391
longer eligible to receive the encrypted password. (Manual
392
intervention is required to re-enable a client.) The timeout,
393
extended timeout, checker program, and interval between checks
394
can be configured both globally and per client; see
395
<citerefentry><refentrytitle>mandos-clients.conf</refentrytitle>
396
<manvolnum>5</manvolnum></citerefentry>.
400
<refsect1 id="approval">
401
<title>APPROVAL</title>
403
The server can be configured to require manual approval for a
404
client before it is sent its secret. The delay to wait for such
405
approval and the default action (approve or deny) can be
406
configured both globally and per client; see <citerefentry>
407
<refentrytitle>mandos-clients.conf</refentrytitle>
408
<manvolnum>5</manvolnum></citerefentry>. By default all clients
409
will be approved immediately without delay.
412
This can be used to deny a client its secret if not manually
413
approved within a specified time. It can also be used to make
414
the server delay before giving a client its secret, allowing
415
optional manual denying of this specific client.
420
<refsect1 id="logging">
421
<title>LOGGING</title>
423
The server will send log message with various severity levels to
424
<filename class="devicefile">/dev/log</filename>. With the
425
<option>--debug</option> option, it will log even more messages,
426
and also show them on the console.
430
<refsect1 id="persistent_state">
431
<title>PERSISTENT STATE</title>
433
Client settings, initially read from
434
<filename>clients.conf</filename>, are persistent across
435
restarts, and run-time changes will override settings in
436
<filename>clients.conf</filename>. However, if a setting is
437
<emphasis>changed</emphasis> (or a client added, or removed) in
438
<filename>clients.conf</filename>, this will take precedence.
442
<refsect1 id="dbus_interface">
443
<title>D-BUS INTERFACE</title>
445
The server will by default provide a D-Bus system bus interface.
446
This interface will only be accessible by the root user or a
447
Mandos-specific user, if such a user exists. For documentation
448
of the D-Bus API, see the file <filename>DBUS-API</filename>.
452
<refsect1 id="exit_status">
453
<title>EXIT STATUS</title>
455
The server will exit with a non-zero exit status only when a
456
critical error is encountered.
460
<refsect1 id="environment">
461
<title>ENVIRONMENT</title>
464
<term><envar>PATH</envar></term>
467
To start the configured checker (see <xref
468
linkend="checking"/>), the server uses
469
<filename>/bin/sh</filename>, which in turn uses
470
<varname>PATH</varname> to search for matching commands if
471
an absolute path is not given. See <citerefentry>
472
<refentrytitle>sh</refentrytitle><manvolnum>1</manvolnum>
480
<refsect1 id="files">
483
Use the <option>--configdir</option> option to change where
484
<command>&COMMANDNAME;</command> looks for its configurations
485
files. The default file names are listed here.
489
<term><filename>/etc/mandos/mandos.conf</filename></term>
492
Server-global settings. See
493
<citerefentry><refentrytitle>mandos.conf</refentrytitle>
494
<manvolnum>5</manvolnum></citerefentry> for details.
499
<term><filename>/etc/mandos/clients.conf</filename></term>
502
List of clients and client-specific settings. See
503
<citerefentry><refentrytitle>mandos-clients.conf</refentrytitle>
504
<manvolnum>5</manvolnum></citerefentry> for details.
509
<term><filename>/var/run/mandos.pid</filename></term>
512
The file containing the process id of the
513
<command>&COMMANDNAME;</command> process started last.
518
<term><filename class="devicefile">/dev/log</filename></term>
522
class="directory">/var/lib/mandos</filename></term>
525
Directory where persistent state will be saved. Change
526
this with the <option>--statedir</option> option. See
527
also the <option>--no-restore</option> option.
532
<term><filename>/dev/log</filename></term>
535
The Unix domain socket to where local syslog messages are
541
<term><filename>/bin/sh</filename></term>
544
This is used to start the configured checker command for
545
each client. See <citerefentry>
546
<refentrytitle>mandos-clients.conf</refentrytitle>
547
<manvolnum>5</manvolnum></citerefentry> for details.
557
This server might, on especially fatal errors, emit a Python
558
backtrace. This could be considered a feature.
561
There is no fine-grained control over logging and debug output.
564
Debug mode is conflated with running in the foreground.
567
This server does not check the expire time of clients’ OpenPGP
572
<refsect1 id="example">
573
<title>EXAMPLE</title>
576
Normal invocation needs no options:
579
<userinput>&COMMANDNAME;</userinput>
584
Run the server in debug mode, read configuration files from
585
the <filename class="directory">~/mandos</filename> directory,
586
and use the Zeroconf service name <quote>Test</quote> to not
587
collide with any other official Mandos server on this host:
591
<!-- do not wrap this line -->
592
<userinput>&COMMANDNAME; --debug --configdir ~/mandos --servicename Test</userinput>
598
Run the server normally, but only listen to one interface and
599
only on the link-local address on that interface:
603
<!-- do not wrap this line -->
604
<userinput>&COMMANDNAME; --interface eth7 --address fe80::aede:48ff:fe71:f6f2</userinput>
610
<refsect1 id="security">
611
<title>SECURITY</title>
612
<refsect2 id="server">
613
<title>SERVER</title>
615
Running this <command>&COMMANDNAME;</command> server program
616
should not in itself present any security risk to the host
617
computer running it. The program switches to a non-root user
621
<refsect2 id="clients">
622
<title>CLIENTS</title>
624
The server only gives out its stored data to clients which
625
does have the OpenPGP key of the stored fingerprint. This is
626
guaranteed by the fact that the client sends its OpenPGP
627
public key in the TLS handshake; this ensures it to be
628
genuine. The server computes the fingerprint of the key
629
itself and looks up the fingerprint in its list of
630
clients. The <filename>clients.conf</filename> file (see
631
<citerefentry><refentrytitle>mandos-clients.conf</refentrytitle>
632
<manvolnum>5</manvolnum></citerefentry>)
633
<emphasis>must</emphasis> be made non-readable by anyone
634
except the user starting the server (usually root).
637
As detailed in <xref linkend="checking"/>, the status of all
638
client computers will continually be checked and be assumed
639
compromised if they are gone for too long.
642
For more details on client-side security, see
643
<citerefentry><refentrytitle>mandos-client</refentrytitle>
644
<manvolnum>8mandos</manvolnum></citerefentry>.
649
<refsect1 id="see_also">
650
<title>SEE ALSO</title>
652
<citerefentry><refentrytitle>intro</refentrytitle>
653
<manvolnum>8mandos</manvolnum></citerefentry>,
654
<citerefentry><refentrytitle>mandos-clients.conf</refentrytitle>
655
<manvolnum>5</manvolnum></citerefentry>,
656
<citerefentry><refentrytitle>mandos.conf</refentrytitle>
657
<manvolnum>5</manvolnum></citerefentry>,
658
<citerefentry><refentrytitle>mandos-client</refentrytitle>
659
<manvolnum>8mandos</manvolnum></citerefentry>,
660
<citerefentry><refentrytitle>sh</refentrytitle>
661
<manvolnum>1</manvolnum></citerefentry>
666
<ulink url="http://www.zeroconf.org/">Zeroconf</ulink>
670
Zeroconf is the network protocol standard used by clients
671
for finding this Mandos server on the local network.
677
<ulink url="http://www.avahi.org/">Avahi</ulink>
681
Avahi is the library this server calls to implement
682
Zeroconf service announcements.
688
<ulink url="http://www.gnu.org/software/gnutls/"
693
GnuTLS is the library this server uses to implement TLS for
694
communicating securely with the client, and at the same time
695
confidently get the client’s public OpenPGP key.
701
RFC 4291: <citetitle>IP Version 6 Addressing
702
Architecture</citetitle>
707
<term>Section 2.2: <citetitle>Text Representation of
708
Addresses</citetitle></term>
709
<listitem><para/></listitem>
712
<term>Section 2.5.5.2: <citetitle>IPv4-Mapped IPv6
713
Address</citetitle></term>
714
<listitem><para/></listitem>
717
<term>Section 2.5.6, <citetitle>Link-Local IPv6 Unicast
718
Addresses</citetitle></term>
721
The clients use IPv6 link-local addresses, which are
722
immediately usable since a link-local addresses is
723
automatically assigned to a network interfaces when it
733
RFC 4346: <citetitle>The Transport Layer Security (TLS)
734
Protocol Version 1.1</citetitle>
738
TLS 1.1 is the protocol implemented by GnuTLS.
744
RFC 4880: <citetitle>OpenPGP Message Format</citetitle>
748
The data sent to clients is binary encrypted OpenPGP data.
754
RFC 5081: <citetitle>Using OpenPGP Keys for Transport Layer
759
This is implemented by GnuTLS and used by this server so
760
that OpenPGP keys can be used.
101
<command>&COMMANDNAME;</command> is a server daemon that handels
102
incomming passwords request for passwords. Mandos use avahi to
103
announce the service, and through gnutls authenticates
104
clients. Any authenticated client is then given its encrypted
110
<term><literal>-h</literal>, <literal>--help</literal></term>
113
show a help message and exit
119
<term><literal>-i</literal>, <literal>--interface <replaceable>
120
IF</replaceable></literal></term>
129
<term><literal>-a</literal>, <literal>--address <replaceable>
130
ADDRESS</replaceable></literal></term>
133
Address to listen for requests on
139
<term><literal>-p</literal>, <literal>--port <replaceable>
140
PORT</replaceable></literal></term>
143
Port number to receive requests on
149
<term><literal>--check</literal></term>
152
Run self-test on the server
158
<term><literal>--debug</literal></term>
167
<term><literal>--priority <replaceable>
168
PRIORITY</replaceable></literal></term>
171
GnuTLS priority string. See <citerefentry>
172
<refentrytitle>gnutls_priority_init</refentrytitle>
173
<manvolnum>3</manvolnum></citerefentry>
179
<term><literal>--servicename <replaceable>NAME</replaceable>
183
Zeroconf service name
189
<term><literal>--configdir <replaceable>DIR</replaceable>
193
Directory to search for configuration files
767
<!-- Local Variables: -->
768
<!-- time-stamp-start: "<!ENTITY TIMESTAMP [\"']" -->
769
<!-- time-stamp-end: "[\"']>" -->
770
<!-- time-stamp-format: "%:y-%02m-%02d" -->