50
67
<refname><command>&COMMANDNAME;</command></refname>
52
Gives encrypted passwords to authenticated Mandos clients
69
Sends encrypted passwords to authenticated mandos clients
58
75
<command>&COMMANDNAME;</command>
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>
98
<arg><option>--no-restore</option></arg>
100
<arg><option>--statedir
101
<replaceable>DIRECTORY</replaceable></option></arg>
104
<command>&COMMANDNAME;</command>
106
<arg choice="plain"><option>--help</option></arg>
107
<arg choice="plain"><option>-h</option></arg>
111
<command>&COMMANDNAME;</command>
112
<arg choice="plain"><option>--version</option></arg>
115
<command>&COMMANDNAME;</command>
116
<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>
120
98
<refsect1 id="description">
121
99
<title>DESCRIPTION</title>
123
<command>&COMMANDNAME;</command> is a server daemon which
124
handles incoming request for passwords for a pre-defined list of
125
client host computers. For an introduction, see
126
<citerefentry><refentrytitle>intro</refentrytitle>
127
<manvolnum>8mandos</manvolnum></citerefentry>. The Mandos server
128
uses Zeroconf to announce itself on the local network, and uses
129
TLS to communicate securely with and to authenticate the
130
clients. The Mandos server uses IPv6 to allow Mandos clients to
131
use IPv6 link-local addresses, since the clients will probably
132
not have any other addresses configured (see <xref
133
linkend="overview"/>). Any authenticated client is then given
134
the stored pre-encrypted password for that specific client.
138
<refsect1 id="purpose">
139
<title>PURPOSE</title>
141
The purpose of this is to enable <emphasis>remote and unattended
142
rebooting</emphasis> of client host computer with an
143
<emphasis>encrypted root file system</emphasis>. See <xref
144
linkend="overview"/> for details.
148
<refsect1 id="options">
149
<title>OPTIONS</title>
152
<term><option>--help</option></term>
153
<term><option>-h</option></term>
156
Show a help message and exit
162
<term><option>--interface</option>
163
<replaceable>NAME</replaceable></term>
164
<term><option>-i</option>
165
<replaceable>NAME</replaceable></term>
167
<xi:include href="mandos-options.xml" xpointer="interface"/>
172
<term><option>--address
173
<replaceable>ADDRESS</replaceable></option></term>
175
<replaceable>ADDRESS</replaceable></option></term>
177
<xi:include href="mandos-options.xml" xpointer="address"/>
183
<replaceable>PORT</replaceable></option></term>
185
<replaceable>PORT</replaceable></option></term>
187
<xi:include href="mandos-options.xml" xpointer="port"/>
192
<term><option>--check</option></term>
195
Run the server’s self-tests. This includes any unit
202
<term><option>--debug</option></term>
204
<xi:include href="mandos-options.xml" xpointer="debug"/>
209
<term><option>--debuglevel
210
<replaceable>LEVEL</replaceable></option></term>
213
Set the debugging log level.
214
<replaceable>LEVEL</replaceable> is a string, one of
215
<quote><literal>CRITICAL</literal></quote>,
216
<quote><literal>ERROR</literal></quote>,
217
<quote><literal>WARNING</literal></quote>,
218
<quote><literal>INFO</literal></quote>, or
219
<quote><literal>DEBUG</literal></quote>, in order of
220
increasing verbosity. The default level is
221
<quote><literal>WARNING</literal></quote>.
227
<term><option>--priority <replaceable>
228
PRIORITY</replaceable></option></term>
230
<xi:include href="mandos-options.xml" xpointer="priority"/>
235
<term><option>--servicename
236
<replaceable>NAME</replaceable></option></term>
238
<xi:include href="mandos-options.xml"
239
xpointer="servicename"/>
244
<term><option>--configdir
245
<replaceable>DIRECTORY</replaceable></option></term>
248
Directory to search for configuration files. Default is
249
<quote><literal>/etc/mandos</literal></quote>. See
250
<citerefentry><refentrytitle>mandos.conf</refentrytitle>
251
<manvolnum>5</manvolnum></citerefentry> and <citerefentry>
252
<refentrytitle>mandos-clients.conf</refentrytitle>
253
<manvolnum>5</manvolnum></citerefentry>.
259
<term><option>--version</option></term>
262
Prints the program version and exit.
268
<term><option>--no-dbus</option></term>
270
<xi:include href="mandos-options.xml" xpointer="dbus"/>
272
See also <xref linkend="dbus_interface"/>.
278
<term><option>--no-ipv6</option></term>
280
<xi:include href="mandos-options.xml" xpointer="ipv6"/>
285
<term><option>--no-restore</option></term>
287
<xi:include href="mandos-options.xml" xpointer="restore"/>
292
<term><option>--statedir
293
<replaceable>DIRECTORY</replaceable></option></term>
295
<xi:include href="mandos-options.xml" xpointer="statedir"/>
301
<refsect1 id="overview">
302
<title>OVERVIEW</title>
303
<xi:include href="overview.xml"/>
305
This program is the server part. It is a normal server program
306
and will run in a normal system environment, not in an initial
307
<acronym>RAM</acronym> disk environment.
311
<refsect1 id="protocol">
312
<title>NETWORK PROTOCOL</title>
314
The Mandos server announces itself as a Zeroconf service of type
315
<quote><literal>_mandos._tcp</literal></quote>. The Mandos
316
client connects to the announced address and port, and sends a
317
line of text where the first whitespace-separated field is the
318
protocol version, which currently is
319
<quote><literal>1</literal></quote>. The client and server then
320
start a TLS protocol handshake with a slight quirk: the Mandos
321
server program acts as a TLS <quote>client</quote> while the
322
connecting Mandos client acts as a TLS <quote>server</quote>.
323
The Mandos client must supply an OpenPGP certificate, and the
324
fingerprint of this certificate is used by the Mandos server to
325
look up (in a list read from <filename>clients.conf</filename>
326
at start time) which binary blob to give the client. No other
327
authentication or authorization is done by the server.
330
<title>Mandos Protocol (Version 1)</title><tgroup cols="3"><thead>
332
<entry>Mandos Client</entry>
333
<entry>Direction</entry>
334
<entry>Mandos Server</entry>
338
<entry>Connect</entry>
339
<entry>-><!-- → --></entry>
342
<entry><quote><literal>1\r\n</literal></quote></entry>
343
<entry>-><!-- → --></entry>
346
<entry>TLS handshake <emphasis>as TLS <quote>server</quote>
348
<entry><-><!-- ⟷ --></entry>
349
<entry>TLS handshake <emphasis>as TLS <quote>client</quote>
353
<entry>OpenPGP public key (part of TLS handshake)</entry>
354
<entry>-><!-- → --></entry>
358
<entry><-<!-- ← --></entry>
359
<entry>Binary blob (client will assume OpenPGP data)</entry>
363
<entry><-<!-- ← --></entry>
366
</tbody></tgroup></table>
369
<refsect1 id="checking">
370
<title>CHECKING</title>
372
The server will, by default, continually check that the clients
373
are still up. If a client has not been confirmed as being up
374
for some time, the client is assumed to be compromised and is no
375
longer eligible to receive the encrypted password. (Manual
376
intervention is required to re-enable a client.) The timeout,
377
extended timeout, checker program, and interval between checks
378
can be configured both globally and per client; see
379
<citerefentry><refentrytitle>mandos-clients.conf</refentrytitle>
380
<manvolnum>5</manvolnum></citerefentry>. A client successfully
381
receiving its password will also be treated as a successful
386
<refsect1 id="approval">
387
<title>APPROVAL</title>
389
The server can be configured to require manual approval for a
390
client before it is sent its secret. The delay to wait for such
391
approval and the default action (approve or deny) can be
392
configured both globally and per client; see <citerefentry>
393
<refentrytitle>mandos-clients.conf</refentrytitle>
394
<manvolnum>5</manvolnum></citerefentry>. By default all clients
395
will be approved immediately without delay.
398
This can be used to deny a client its secret if not manually
399
approved within a specified time. It can also be used to make
400
the server delay before giving a client its secret, allowing
401
optional manual denying of this specific client.
406
<refsect1 id="logging">
407
<title>LOGGING</title>
409
The server will send log message with various severity levels to
410
<filename>/dev/log</filename>. With the
411
<option>--debug</option> option, it will log even more messages,
412
and also show them on the console.
416
<refsect1 id="dbus_interface">
417
<title>D-BUS INTERFACE</title>
419
The server will by default provide a D-Bus system bus interface.
420
This interface will only be accessible by the root user or a
421
Mandos-specific user, if such a user exists. For documentation
422
of the D-Bus API, see the file <filename>DBUS-API</filename>.
426
<refsect1 id="exit_status">
427
<title>EXIT STATUS</title>
429
The server will exit with a non-zero exit status only when a
430
critical error is encountered.
434
<refsect1 id="environment">
435
<title>ENVIRONMENT</title>
438
<term><envar>PATH</envar></term>
441
To start the configured checker (see <xref
442
linkend="checking"/>), the server uses
443
<filename>/bin/sh</filename>, which in turn uses
444
<varname>PATH</varname> to search for matching commands if
445
an absolute path is not given. See <citerefentry>
446
<refentrytitle>sh</refentrytitle><manvolnum>1</manvolnum>
454
<refsect1 id="files">
457
Use the <option>--configdir</option> option to change where
458
<command>&COMMANDNAME;</command> looks for its configurations
459
files. The default file names are listed here.
463
<term><filename>/etc/mandos/mandos.conf</filename></term>
466
Server-global settings. See
467
<citerefentry><refentrytitle>mandos.conf</refentrytitle>
468
<manvolnum>5</manvolnum></citerefentry> for details.
473
<term><filename>/etc/mandos/clients.conf</filename></term>
476
List of clients and client-specific settings. See
477
<citerefentry><refentrytitle>mandos-clients.conf</refentrytitle>
478
<manvolnum>5</manvolnum></citerefentry> for details.
483
<term><filename>/var/run/mandos.pid</filename></term>
486
The file containing the process id of the
487
<command>&COMMANDNAME;</command> process started last.
493
class="directory">/var/lib/mandos</filename></term>
496
Directory where persistent state will be saved. Change
497
this with the <option>--statedir</option> option. See
498
also the <option>--no-restore</option> option.
503
<term><filename>/dev/log</filename></term>
506
The Unix domain socket to where local syslog messages are
512
<term><filename>/bin/sh</filename></term>
515
This is used to start the configured checker command for
516
each client. See <citerefentry>
517
<refentrytitle>mandos-clients.conf</refentrytitle>
518
<manvolnum>5</manvolnum></citerefentry> for details.
528
This server might, on especially fatal errors, emit a Python
529
backtrace. This could be considered a feature.
532
There is no fine-grained control over logging and debug output.
535
Debug mode is conflated with running in the foreground.
538
This server does not check the expire time of clients’ OpenPGP
543
<refsect1 id="example">
544
<title>EXAMPLE</title>
547
Normal invocation needs no options:
550
<userinput>&COMMANDNAME;</userinput>
555
Run the server in debug mode, read configuration files from
556
the <filename class="directory">~/mandos</filename> directory,
557
and use the Zeroconf service name <quote>Test</quote> to not
558
collide with any other official Mandos server on this host:
562
<!-- do not wrap this line -->
563
<userinput>&COMMANDNAME; --debug --configdir ~/mandos --servicename Test</userinput>
569
Run the server normally, but only listen to one interface and
570
only on the link-local address on that interface:
574
<!-- do not wrap this line -->
575
<userinput>&COMMANDNAME; --interface eth7 --address fe80::aede:48ff:fe71:f6f2</userinput>
581
<refsect1 id="security">
582
<title>SECURITY</title>
583
<refsect2 id="server">
584
<title>SERVER</title>
586
Running this <command>&COMMANDNAME;</command> server program
587
should not in itself present any security risk to the host
588
computer running it. The program switches to a non-root user
592
<refsect2 id="clients">
593
<title>CLIENTS</title>
595
The server only gives out its stored data to clients which
596
does have the OpenPGP key of the stored fingerprint. This is
597
guaranteed by the fact that the client sends its OpenPGP
598
public key in the TLS handshake; this ensures it to be
599
genuine. The server computes the fingerprint of the key
600
itself and looks up the fingerprint in its list of
601
clients. The <filename>clients.conf</filename> file (see
602
<citerefentry><refentrytitle>mandos-clients.conf</refentrytitle>
603
<manvolnum>5</manvolnum></citerefentry>)
604
<emphasis>must</emphasis> be made non-readable by anyone
605
except the user starting the server (usually root).
608
As detailed in <xref linkend="checking"/>, the status of all
609
client computers will continually be checked and be assumed
610
compromised if they are gone for too long.
613
For more details on client-side security, see
614
<citerefentry><refentrytitle>mandos-client</refentrytitle>
615
<manvolnum>8mandos</manvolnum></citerefentry>.
620
<refsect1 id="see_also">
621
<title>SEE ALSO</title>
623
<citerefentry><refentrytitle>intro</refentrytitle>
624
<manvolnum>8mandos</manvolnum></citerefentry>,
625
<citerefentry><refentrytitle>mandos-clients.conf</refentrytitle>
626
<manvolnum>5</manvolnum></citerefentry>,
627
<citerefentry><refentrytitle>mandos.conf</refentrytitle>
628
<manvolnum>5</manvolnum></citerefentry>,
629
<citerefentry><refentrytitle>mandos-client</refentrytitle>
630
<manvolnum>8mandos</manvolnum></citerefentry>,
631
<citerefentry><refentrytitle>sh</refentrytitle>
632
<manvolnum>1</manvolnum></citerefentry>
637
<ulink url="http://www.zeroconf.org/">Zeroconf</ulink>
641
Zeroconf is the network protocol standard used by clients
642
for finding this Mandos server on the local network.
648
<ulink url="http://www.avahi.org/">Avahi</ulink>
652
Avahi is the library this server calls to implement
653
Zeroconf service announcements.
659
<ulink url="http://www.gnu.org/software/gnutls/"
664
GnuTLS is the library this server uses to implement TLS for
665
communicating securely with the client, and at the same time
666
confidently get the client’s public OpenPGP key.
672
RFC 4291: <citetitle>IP Version 6 Addressing
673
Architecture</citetitle>
678
<term>Section 2.2: <citetitle>Text Representation of
679
Addresses</citetitle></term>
680
<listitem><para/></listitem>
683
<term>Section 2.5.5.2: <citetitle>IPv4-Mapped IPv6
684
Address</citetitle></term>
685
<listitem><para/></listitem>
688
<term>Section 2.5.6, <citetitle>Link-Local IPv6 Unicast
689
Addresses</citetitle></term>
692
The clients use IPv6 link-local addresses, which are
693
immediately usable since a link-local addresses is
694
automatically assigned to a network interfaces when it
704
RFC 4346: <citetitle>The Transport Layer Security (TLS)
705
Protocol Version 1.1</citetitle>
709
TLS 1.1 is the protocol implemented by GnuTLS.
715
RFC 4880: <citetitle>OpenPGP Message Format</citetitle>
719
The data sent to clients is binary encrypted OpenPGP data.
725
RFC 5081: <citetitle>Using OpenPGP Keys for Transport Layer
730
This is implemented by GnuTLS and used by this server so
731
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
738
<!-- Local Variables: -->
739
<!-- time-stamp-start: "<!ENTITY TIMESTAMP [\"']" -->
740
<!-- time-stamp-end: "[\"']>" -->
741
<!-- time-stamp-format: "%:y-%02m-%02d" -->