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<command>&COMMANDNAME;</command>
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<arg choice='opt'>-i<arg choice='plain'>IF</arg></arg>
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<arg choice='opt'>-a<arg choice='plain'>ADDRESS</arg></arg>
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<arg choice='opt'>-p<arg choice='plain'>PORT</arg></arg>
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<arg choice='opt'>--priority<arg choice='plain'>PRIORITY</arg></arg>
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<arg choice='opt'>--servicename<arg choice='plain'>NAME</arg></arg>
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<arg choice='opt'>--configdir<arg choice='plain'>DIRECTORY</arg></arg>
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<arg choice='opt'>--debug</arg>
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<command>&COMMANDNAME;</command>
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<arg choice='plain'>--help</arg>
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<command>&COMMANDNAME;</command>
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<arg choice='plain'>--check</arg>
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<command>&COMMANDNAME;</command>
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<arg choice='plain'>--version</arg>
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<command>&COMMANDNAME;</command>
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<arg choice='plain'>--check</arg>
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<refsect1 id="description">
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99
<title>DESCRIPTION</title>
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<command>&COMMANDNAME;</command> is a server daemon which
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handles incoming request for passwords for a pre-defined list of
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client host computers. The Mandos server uses Zeroconf to
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announce itself on the local network, and uses GnuTLS to
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communicate securely with and to authenticate the clients.
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Mandos uses IPv6 link-local addresses, since the clients are
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assumed to not have any other addresses configured. Any
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authenticated client is then given the pre-encrypted password
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for that specific client.
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<refsect1 id="purpose">
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<title>PURPOSE</title>
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The purpose of this is to enable <emphasis>remote and unattended
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rebooting</emphasis> of any client host computer with an
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<emphasis>encrypted root file system</emphasis>. The client
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host computer should start a Mandos client in the initial RAM
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disk environment, the Mandos client program communicates with
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this server program to get an encrypted password, which is then
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decrypted and used to unlock the encrypted root file system.
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The client host computer can then continue its boot sequence
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<refsect1 id="options">
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<title>OPTIONS</title>
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<command>&COMMANDNAME;</command> is a server daemon that handels
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incomming passwords request for passwords. Mandos use avahi to
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announce the service, and through gnutls authenticates
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clients. Any authenticated client is then given its encrypted
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<term><literal>-h</literal>, <literal>--help</literal></term>
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Show a help message and exit
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show a help message and exit
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IF</replaceable></literal></term>
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Only announce the server and listen to requests on network
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interface <replaceable>IF</replaceable>. Default is to
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use all available interfaces.
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<term><literal>-a</literal>, <literal>--address <replaceable>
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ADDRESS</replaceable></literal></term>
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If this option is used, the server will only listen to a
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specific address. This must currently be an IPv6 address;
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an IPv4 address can be specified using the
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<quote><literal>::FFFF:192.0.2.3</literal></quote> syntax.
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Also, if a link-local address is specified, an interface
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should be set, since a link-local address is only valid on
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a single interface. By default, the server will listen to
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all available addresses.
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Address to listen for requests on
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<term><literal>-p</literal>, <literal>--port <replaceable>
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140
PORT</replaceable></literal></term>
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If this option is used, the server to bind to that
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port. By default, the server will listen to an arbitrary
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port given by the operating system.
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Port number to receive requests on
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<term><literal>--check</literal></term>
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Run the server's self-tests. This includes any unit
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Run self-test on the server
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<term><literal>--debug</literal></term>
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If the server is run in debug mode, it will run in the
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foreground and print a lot of debugging information. The
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default is <emphasis>not</emphasis> to run in debug mode.
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PRIORITY</replaceable></literal></term>
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GnuTLS priority string for the TLS handshake with the
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<citerefentry><refentrytitle>gnutls_priority_init
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</refentrytitle><manvolnum>3</manvolnum></citerefentry>
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for the syntax. The default is
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<quote><literal>SECURE256:!CTYPE-X.509:+CTYPE-OPENPGP</literal></quote>.
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<emphasis>Warning</emphasis>: changing this may make the
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TLS handshake fail, making communication with clients
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GnuTLS priority string. See <citerefentry>
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<refentrytitle>gnutls_priority_init</refentrytitle>
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<manvolnum>3</manvolnum></citerefentry>
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<term><literal>--servicename <replaceable>NAME</replaceable>
237
180
</literal></term>
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Zeroconf service name. The default is
241
<quote><literal>Mandos</literal></quote>. You only need
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to change this if you for some reason want to run more
243
than one server on the same <emphasis>host</emphasis>,
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which would not normally be useful. If there are name
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collisions on the same <emphasis>network</emphasis>, the
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newer server will automatically rename itself to
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<quote><literal>Mandos #2</literal></quote>, and so on,
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therefore this option is not needed in that case.
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Zeroconf service name
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<term><literal>--configdir <replaceable>DIR</replaceable>
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190
</literal></term>
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Directory to search for configuration files. Default is
259
<quote><literal>/etc/mandos</literal></quote>. See
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<citerefentry><refentrytitle>mandos.conf</refentrytitle>
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<manvolnum>5</manvolnum></citerefentry> and <citerefentry>
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<refentrytitle>mandos-clients.conf</refentrytitle>
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<manvolnum>5</manvolnum></citerefentry>.
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<term><literal>--version</literal></term>
272
Prints the program version and exit.
279
<refsect1 id="protocol">
280
<title>NETWORK PROTOCOL</title>
282
The Mandos server announces itself as a Zeroconf service of type
283
<quote><literal>_mandos._tcp</literal></quote>. The Mandos
284
client connects to the announced address and port, and sends a
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line of text where the first whitespace-separated field is the
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protocol version, which currently is
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<quote><literal>1</literal></quote>. The client and server then
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start a TLS protocol handshake with a slight quirk: the Mandos
289
server program acts as a TLS <quote>client</quote> while the
290
connecting Mandos client acts as a TLS <quote>server</quote>.
291
The Mandos client must supply an OpenPGP certificate, and the
292
fingerprint of this certificate is used by the Mandos server to
293
look up (in a list read from <filename>clients.conf</filename>
294
at start time) which binary blob to give the client. No other
295
authentication or authorization is done by the server.
298
<title>Mandos Protocol (Version 1)</title><tgroup cols="3"><thead>
300
<entry>Mandos Client</entry>
301
<entry>Direction</entry>
302
<entry>Mandos Server</entry>
306
<entry>Connect</entry>
307
<entry>-><!-- → --></entry>
310
<entry><quote><literal>1\r\en</literal></quote></entry>
311
<entry>-><!-- → --></entry>
314
<entry>TLS handshake <emphasis>as TLS <quote>server</quote>
316
<entry><-><!-- ⟷ --></entry>
317
<entry>TLS handshake <emphasis>as TLS <quote>client</quote>
321
<entry>OpenPGP public key (part of TLS handshake)</entry>
322
<entry>-><!-- → --></entry>
326
<entry><-<!-- ← --></entry>
327
<entry>Binary blob (client will assume OpenPGP data)</entry>
331
<entry><-<!-- ← --></entry>
334
</tbody></tgroup></table>
337
<refsect1 id="checking">
338
<title>CHECKING</title>
340
The server will, by default, continually check that the clients
341
are still up. If a client has not been confirmed as being up
342
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>
348
<refentrytitle>mandos-clients.conf</refentrytitle>
349
<manvolnum>5</manvolnum></citerefentry>.
353
<refsect1 id="logging">
354
<title>LOGGING</title>
356
The server will send log messaged with various severity levels
357
to <filename>/dev/log</filename>. With the
358
<option>--debug</option> option, it will log even more messages,
359
and also show them on the console.
363
<refsect1 id="exit_status">
364
<title>EXIT STATUS</title>
366
The server will exit with a non-zero exit status only when a
367
critical error is encountered.
374
Use the <option>--configdir</option> option to change where
375
<command>&COMMANDNAME;</command> looks for its configurations
376
files. The default file names are listed here.
380
<term><filename>/etc/mandos/mandos.conf</filename></term>
383
Server-global settings. See
384
<citerefentry><refentrytitle>mandos.conf</refentrytitle>
385
<manvolnum>5</manvolnum></citerefentry> for details.
390
<term><filename>/etc/mandos/clients.conf</filename></term>
393
List of clients and client-specific settings. See
394
<citerefentry><refentrytitle>mandos-clients.conf</refentrytitle>
395
<manvolnum>5</manvolnum></citerefentry> for details.
400
<term><filename>/var/run/mandos/mandos.pid</filename></term>
403
The file containing the process id of
404
<command>&COMMANDNAME;</command>.
409
<term><filename>/dev/log</filename></term>
412
The Unix domain socket to where local syslog messages are
423
This server might, on especially fatal errors, emit a Python
424
backtrace. This could be considered a feature.
428
<refsect1 id="examples">
429
<title>EXAMPLES</title>
432
Normal invocation needs no options:
435
<userinput>mandos</userinput>
440
Run the server in debug mode and read configuration files from
441
the <filename>~/mandos</filename> directory:
445
<!-- do not wrap this line -->
446
<userinput>mandos --debug --configdir ~/mandos --servicename Test</userinput>
452
Run the server normally, but only listen to one interface and
453
only on the link-local address on that interface:
457
<!-- do not wrap this line -->
458
<userinput>mandos --interface eth7 --address fe80::aede:48ff:fe71:f6f2</userinput>
464
<refsect1 id="security">
465
<title>SECURITY</title>
467
<title>SERVER</title>
469
Running the server should not in itself present any security
470
risk to the host computer running it.
474
<title>CLIENTS</title>
476
The server only gives out its stored data to clients which
477
does have the OpenPGP key of the stored fingerprint. This is
478
guaranteed by the fact that the client sends its OpenPGP
479
public key in the TLS handshake; this ensures it to be
480
genuine. The server computes the fingerprint of the key
481
itself and looks up the fingerprint in its list of
482
clients. The <filename>clients.conf</filename> file (see
483
<citerefentry><refentrytitle>mandos-clients.conf</refentrytitle>
484
<manvolnum>5</manvolnum></citerefentry>) must be non-readable
485
by anyone except the user running the server.
488
For more details on client-side security, see
489
<citerefentry><refentrytitle>password-request</refentrytitle>
490
<manvolnum>8mandos</manvolnum></citerefentry>.
495
<refsect1 id="see_also">
496
<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>
193
Directory to search for configuration files