48
68
<refname><command>&COMMANDNAME;</command></refname>
50
Gives encrypted passwords to authenticated Mandos clients
70
Sends encrypted passwords to authenticated Mandos clients
56
76
<command>&COMMANDNAME;</command>
58
<arg choice="plain"><option>--interface
59
<replaceable>NAME</replaceable></option></arg>
60
<arg choice="plain"><option>-i
61
<replaceable>NAME</replaceable></option></arg>
65
<arg choice="plain"><option>--address
66
<replaceable>ADDRESS</replaceable></option></arg>
67
<arg choice="plain"><option>-a
68
<replaceable>ADDRESS</replaceable></option></arg>
72
<arg choice="plain"><option>--port
73
<replaceable>PORT</replaceable></option></arg>
74
<arg choice="plain"><option>-p
75
<replaceable>PORT</replaceable></option></arg>
78
<arg><option>--priority
79
<replaceable>PRIORITY</replaceable></option></arg>
81
<arg><option>--servicename
82
<replaceable>NAME</replaceable></option></arg>
84
<arg><option>--configdir
85
<replaceable>DIRECTORY</replaceable></option></arg>
87
<arg><option>--debug</option></arg>
90
<command>&COMMANDNAME;</command>
92
<arg choice="plain"><option>--help</option></arg>
93
<arg choice="plain"><option>-h</option></arg>
97
<command>&COMMANDNAME;</command>
98
<arg choice="plain"><option>--version</option></arg>
101
<command>&COMMANDNAME;</command>
102
<arg choice="plain"><option>--check</option></arg>
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>
104
107
</refsynopsisdiv>
106
109
<refsect1 id="description">
107
110
<title>DESCRIPTION</title>
109
112
<command>&COMMANDNAME;</command> is a server daemon which
110
113
handles incoming request for passwords for a pre-defined list of
111
114
client host computers. The Mandos server uses Zeroconf to
112
announce itself on the local network, and uses TLS to
113
communicate securely with and to authenticate the clients. The
114
Mandos server uses IPv6 to allow Mandos clients to use IPv6
115
link-local addresses, since the clients will probably not have
116
any other addresses configured (see <xref linkend="overview"/>).
117
Any authenticated client is then given the stored pre-encrypted
118
password for that specific client.
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.
122
125
<refsect1 id="purpose">
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126
<title>PURPOSE</title>
125
129
The purpose of this is to enable <emphasis>remote and unattended
126
rebooting</emphasis> of client host computer with an
127
<emphasis>encrypted root file system</emphasis>. See <xref
128
linkend="overview"/> for details.
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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
133
disk environment, the Mandos client program communicates with
134
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.
136
The client host computer can then continue its boot sequence
132
142
<refsect1 id="options">
133
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<title>OPTIONS</title>
136
<term><option>--help</option></term>
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<term><option>-h</option></term>
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<term><literal>-h</literal>, <literal>--help</literal></term>
140
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Show a help message and exit
146
<term><option>--interface</option>
147
<replaceable>NAME</replaceable></term>
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<term><option>-i</option>
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<replaceable>NAME</replaceable></term>
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<xi:include href="mandos-options.xml" xpointer="interface"/>
156
<term><option>--address
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<replaceable>ADDRESS</replaceable></option></term>
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<replaceable>ADDRESS</replaceable></option></term>
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<xi:include href="mandos-options.xml" xpointer="address"/>
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<replaceable>PORT</replaceable></option></term>
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<replaceable>PORT</replaceable></option></term>
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<xi:include href="mandos-options.xml" xpointer="port"/>
176
<term><option>--check</option></term>
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Run the server’s self-tests. This includes any unit
156
<term><literal>-i</literal>, <literal>--interface <replaceable>
157
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>
169
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
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
186
<term><option>--debug</option></term>
188
<xi:include href="mandos-options.xml" xpointer="debug"/>
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<term><option>--priority <replaceable>
194
PRIORITY</replaceable></option></term>
196
<xi:include href="mandos-options.xml" xpointer="priority"/>
201
<term><option>--servicename
202
<replaceable>NAME</replaceable></option></term>
204
<xi:include href="mandos-options.xml"
205
xpointer="servicename"/>
210
<term><option>--configdir
211
<replaceable>DIRECTORY</replaceable></option></term>
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>
214
258
Directory to search for configuration files. Default is
402
<term><filename>/bin/sh</filename></term>
405
This is used to start the configured checker command for
406
each client. See <citerefentry>
407
<refentrytitle>mandos-clients.conf</refentrytitle>
408
<manvolnum>5</manvolnum></citerefentry> for details.
415
420
<refsect1 id="bugs">
416
421
<title>BUGS</title>
418
423
This server might, on especially fatal errors, emit a Python
419
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backtrace. This could be considered a feature.
422
Currently, if a client is declared <quote>invalid</quote> due to
423
having timed out, the server does not record this fact onto
424
permanent storage. This has some security implications, see
425
<xref linkend="clients"/>.
428
There is currently no way of querying the server of the current
429
status of clients, other than analyzing its <systemitem
430
class="service">syslog</systemitem> output.
433
There is no fine-grained control over logging and debug output.
436
Debug mode is conflated with running in the foreground.
439
The console log messages does not show a time stamp.
442
This server does not check the expire time of clients’ OpenPGP
447
<refsect1 id="example">
448
<title>EXAMPLE</title>
428
<refsect1 id="examples">
429
<title>EXAMPLES</title>
449
430
<informalexample>
451
432
Normal invocation needs no options:
454
<userinput>&COMMANDNAME;</userinput>
435
<userinput>mandos</userinput>
456
437
</informalexample>
457
438
<informalexample>
459
Run the server in debug mode, read configuration files from
460
the <filename>~/mandos</filename> directory, and use the
461
Zeroconf service name <quote>Test</quote> to not collide with
462
any other official Mandos server on this host:
440
Run the server in debug mode and read configuration files from
441
the <filename>~/mandos</filename> directory:
466
445
<!-- do not wrap this line -->
467
<userinput>&COMMANDNAME; --debug --configdir ~/mandos --servicename Test</userinput>
446
<userinput>mandos --debug --configdir ~/mandos --servicename Test</userinput>
470
449
</informalexample>
504
481
itself and looks up the fingerprint in its list of
505
482
clients. The <filename>clients.conf</filename> file (see
506
483
<citerefentry><refentrytitle>mandos-clients.conf</refentrytitle>
507
<manvolnum>5</manvolnum></citerefentry>)
508
<emphasis>must</emphasis> be made non-readable by anyone
509
except the user starting the server (usually root).
512
As detailed in <xref linkend="checking"/>, the status of all
513
client computers will continually be checked and be assumed
514
compromised if they are gone for too long.
517
If a client is compromised, its downtime should be duly noted
518
by the server which would therefore declare the client
519
invalid. But if the server was ever restarted, it would
520
re-read its client list from its configuration file and again
521
regard all clients therein as valid, and hence eligible to
522
receive their passwords. Therefore, be careful when
523
restarting servers if it is suspected that a client has, in
524
fact, been compromised by parties who may now be running a
525
fake Mandos client with the keys from the non-encrypted
526
initial <acronym>RAM</acronym> image of the client host. What
527
should be done in that case (if restarting the server program
528
really is necessary) is to stop the server program, edit the
529
configuration file to omit any suspect clients, and restart
484
<manvolnum>5</manvolnum></citerefentry>) must be non-readable
485
by anyone except the user running the server.
533
488
For more details on client-side security, see
534
<citerefentry><refentrytitle>mandos-client</refentrytitle>
489
<citerefentry><refentrytitle>password-request</refentrytitle>
535
490
<manvolnum>8mandos</manvolnum></citerefentry>.
540
495
<refsect1 id="see_also">
541
496
<title>SEE ALSO</title>
544
<refentrytitle>mandos-clients.conf</refentrytitle>
545
<manvolnum>5</manvolnum></citerefentry>, <citerefentry>
546
<refentrytitle>mandos.conf</refentrytitle>
547
<manvolnum>5</manvolnum></citerefentry>, <citerefentry>
548
<refentrytitle>mandos-client</refentrytitle>
549
<manvolnum>8mandos</manvolnum></citerefentry>, <citerefentry>
550
<refentrytitle>sh</refentrytitle><manvolnum>1</manvolnum>
556
<ulink url="http://www.zeroconf.org/">Zeroconf</ulink>
560
Zeroconf is the network protocol standard used by clients
561
for finding this Mandos server on the local network.
567
<ulink url="http://www.avahi.org/">Avahi</ulink>
571
Avahi is the library this server calls to implement
572
Zeroconf service announcements.
578
<ulink url="http://www.gnu.org/software/gnutls/"
583
GnuTLS is the library this server uses to implement TLS for
584
communicating securely with the client, and at the same time
585
confidently get the client’s public OpenPGP key.
591
RFC 4291: <citetitle>IP Version 6 Addressing
592
Architecture</citetitle>
597
<term>Section 2.2: <citetitle>Text Representation of
598
Addresses</citetitle></term>
599
<listitem><para/></listitem>
602
<term>Section 2.5.5.2: <citetitle>IPv4-Mapped IPv6
603
Address</citetitle></term>
604
<listitem><para/></listitem>
607
<term>Section 2.5.6, <citetitle>Link-Local IPv6 Unicast
608
Addresses</citetitle></term>
611
The clients use IPv6 link-local addresses, which are
612
immediately usable since a link-local addresses is
613
automatically assigned to a network interfaces when it
623
RFC 4346: <citetitle>The Transport Layer Security (TLS)
624
Protocol Version 1.1</citetitle>
628
TLS 1.1 is the protocol implemented by GnuTLS.
634
RFC 4880: <citetitle>OpenPGP Message Format</citetitle>
638
The data sent to clients is binary encrypted OpenPGP data.
644
RFC 5081: <citetitle>Using OpenPGP Keys for Transport Layer
649
This is implemented by GnuTLS and used by this server so
650
that OpenPGP keys can be used.
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>
657
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