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19
<firstname>Björn</firstname>
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20
<surname>Påhlsson</surname>
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<email>belorn@fukt.bsnet.se</email>
22
<email>belorn@recompile.se</email>
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26
<firstname>Teddy</firstname>
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27
<surname>Hogeborn</surname>
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<email>teddy@fukt.bsnet.se</email>
29
<email>teddy@recompile.se</email>
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46
<holder>Teddy Hogeborn</holder>
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47
<holder>Björn Påhlsson</holder>
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<arg><option>--debug</option></arg>
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<arg><option>--debuglevel
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<replaceable>LEVEL</replaceable></option></arg>
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<arg><option>--no-dbus</option></arg>
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<arg><option>--no-ipv6</option></arg>
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<arg><option>--no-restore</option></arg>
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<arg><option>--statedir
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<replaceable>DIRECTORY</replaceable></option></arg>
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<arg><option>--socket
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<replaceable>FD</replaceable></option></arg>
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<arg><option>--foreground</option></arg>
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<arg><option>--no-zeroconf</option></arg>
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<command>&COMMANDNAME;</command>
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138
<command>&COMMANDNAME;</command> is a server daemon which
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139
handles incoming request for passwords for a pre-defined list of
112
client host computers. The Mandos server uses Zeroconf to
113
announce itself on the local network, and uses TLS to
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communicate securely with and to authenticate the clients. The
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Mandos server uses IPv6 to allow Mandos clients to use IPv6
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link-local addresses, since the clients will probably not have
117
any other addresses configured (see <xref linkend="overview"/>).
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Any authenticated client is then given the stored pre-encrypted
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password for that specific client.
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client host computers. For an introduction, see
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<citerefentry><refentrytitle>intro</refentrytitle>
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<manvolnum>8mandos</manvolnum></citerefentry>. The Mandos server
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uses Zeroconf to announce itself on the local network, and uses
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TLS to communicate securely with and to authenticate the
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clients. The Mandos server uses IPv6 to allow Mandos clients to
146
use IPv6 link-local addresses, since the clients will probably
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not have any other addresses configured (see <xref
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linkend="overview"/>). Any authenticated client is then given
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the stored pre-encrypted password for that specific client.
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<term><option>--debuglevel
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<replaceable>LEVEL</replaceable></option></term>
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Set the debugging log level.
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<replaceable>LEVEL</replaceable> is a string, one of
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<quote><literal>CRITICAL</literal></quote>,
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<quote><literal>ERROR</literal></quote>,
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<quote><literal>WARNING</literal></quote>,
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<quote><literal>INFO</literal></quote>, or
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<quote><literal>DEBUG</literal></quote>, in order of
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increasing verbosity. The default level is
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<quote><literal>WARNING</literal></quote>.
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<term><option>--priority <replaceable>
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PRIORITY</replaceable></option></term>
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<xi:include href="mandos-options.xml" xpointer="dbus"/>
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See also <xref linkend="dbus"/>.
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See also <xref linkend="dbus_interface"/>.
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<term><option>--no-ipv6</option></term>
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<xi:include href="mandos-options.xml" xpointer="ipv6"/>
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<term><option>--no-restore</option></term>
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<xi:include href="mandos-options.xml" xpointer="restore"/>
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See also <xref linkend="persistent_state"/>.
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<term><option>--statedir
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<replaceable>DIRECTORY</replaceable></option></term>
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<xi:include href="mandos-options.xml" xpointer="statedir"/>
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<term><option>--socket
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<replaceable>FD</replaceable></option></term>
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<xi:include href="mandos-options.xml" xpointer="socket"/>
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<term><option>--foreground</option></term>
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<xi:include href="mandos-options.xml"
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xpointer="foreground"/>
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<term><option>--no-zeroconf</option></term>
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<xi:include href="mandos-options.xml" xpointer="zeroconf"/>
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start a TLS protocol handshake with a slight quirk: the Mandos
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server program acts as a TLS <quote>client</quote> while the
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connecting Mandos client acts as a TLS <quote>server</quote>.
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The Mandos client must supply an OpenPGP certificate, and the
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fingerprint of this certificate is used by the Mandos server to
269
look up (in a list read from <filename>clients.conf</filename>
270
at start time) which binary blob to give the client. No other
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authentication or authorization is done by the server.
365
The Mandos client must supply a TLS public key, and the key ID
366
of this public key is used by the Mandos server to look up (in a
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list read from <filename>clients.conf</filename> at start time)
368
which binary blob to give the client. No other authentication
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or authorization is done by the server.
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372
<title>Mandos Protocol (Version 1)</title><tgroup cols="3"><thead>
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414
The server will, by default, continually check that the clients
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are still up. If a client has not been confirmed as being up
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for some time, the client is assumed to be compromised and is no
319
longer eligible to receive the encrypted password. The timeout,
320
checker program, and interval between checks can be configured
321
both globally and per client; see <citerefentry>
417
longer eligible to receive the encrypted password. (Manual
418
intervention is required to re-enable a client.) The timeout,
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extended timeout, checker program, and interval between checks
420
can be configured both globally and per client; see
421
<citerefentry><refentrytitle>mandos-clients.conf</refentrytitle>
422
<manvolnum>5</manvolnum></citerefentry>.
426
<refsect1 id="approval">
427
<title>APPROVAL</title>
429
The server can be configured to require manual approval for a
430
client before it is sent its secret. The delay to wait for such
431
approval and the default action (approve or deny) can be
432
configured both globally and per client; see <citerefentry>
322
433
<refentrytitle>mandos-clients.conf</refentrytitle>
323
<manvolnum>5</manvolnum></citerefentry>.
434
<manvolnum>5</manvolnum></citerefentry>. By default all clients
435
will be approved immediately without delay.
438
This can be used to deny a client its secret if not manually
439
approved within a specified time. It can also be used to make
440
the server delay before giving a client its secret, allowing
441
optional manual denying of this specific client.
327
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<refsect1 id="logging">
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<title>LOGGING</title>
330
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The server will send log message with various severity levels to
331
<filename>/dev/log</filename>. With the
450
<filename class="devicefile">/dev/log</filename>. With the
332
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<option>--debug</option> option, it will log even more messages,
333
452
and also show them on the console.
456
<refsect1 id="persistent_state">
457
<title>PERSISTENT STATE</title>
459
Client settings, initially read from
460
<filename>clients.conf</filename>, are persistent across
461
restarts, and run-time changes will override settings in
462
<filename>clients.conf</filename>. However, if a setting is
463
<emphasis>changed</emphasis> (or a client added, or removed) in
464
<filename>clients.conf</filename>, this will take precedence.
468
<refsect1 id="dbus_interface">
338
469
<title>D-BUS INTERFACE</title>
340
471
The server will by default provide a D-Bus system bus interface.
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This interface will only be accessible by the root user or a
342
Mandos-specific user, if such a user exists.
473
Mandos-specific user, if such a user exists. For documentation
474
of the D-Bus API, see the file <filename>DBUS-API</filename>.
347
478
<refsect1 id="exit_status">
348
479
<title>EXIT STATUS</title>
404
<term><filename>/var/run/mandos.pid</filename></term>
407
The file containing the process id of
408
<command>&COMMANDNAME;</command>.
413
<term><filename>/dev/log</filename></term>
535
<term><filename>/run/mandos.pid</filename></term>
538
The file containing the process id of the
539
<command>&COMMANDNAME;</command> process started last.
540
<emphasis >Note:</emphasis> If the <filename
541
class="directory">/run</filename> directory does not
542
exist, <filename>/var/run/mandos.pid</filename> will be
549
class="directory">/var/lib/mandos</filename></term>
552
Directory where persistent state will be saved. Change
553
this with the <option>--statedir</option> option. See
554
also the <option>--no-restore</option> option.
559
<term><filename class="devicefile">/dev/log</filename></term>
416
562
The Unix domain socket to where local syslog messages are
439
585
backtrace. This could be considered a feature.
442
Currently, if a client is declared <quote>invalid</quote> due to
443
having timed out, the server does not record this fact onto
444
permanent storage. This has some security implications, see
445
<xref linkend="clients"/>.
448
There is currently no way of querying the server of the current
449
status of clients, other than analyzing its <systemitem
450
class="service">syslog</systemitem> output.
453
588
There is no fine-grained control over logging and debug output.
456
Debug mode is conflated with running in the foreground.
459
The console log messages does not show a time stamp.
462
This server does not check the expire time of clients’ OpenPGP
590
<xi:include href="bugs.xml"/>
467
593
<refsect1 id="example">
477
603
<informalexample>
479
605
Run the server in debug mode, read configuration files from
480
the <filename>~/mandos</filename> directory, and use the
481
Zeroconf service name <quote>Test</quote> to not collide with
482
any other official Mandos server on this host:
606
the <filename class="directory">~/mandos</filename> directory,
607
and use the Zeroconf service name <quote>Test</quote> to not
608
collide with any other official Mandos server on this host:
517
643
<title>CLIENTS</title>
519
645
The server only gives out its stored data to clients which
520
does have the OpenPGP key of the stored fingerprint. This is
521
guaranteed by the fact that the client sends its OpenPGP
522
public key in the TLS handshake; this ensures it to be
523
genuine. The server computes the fingerprint of the key
524
itself and looks up the fingerprint in its list of
525
clients. The <filename>clients.conf</filename> file (see
646
does have the correct key ID of the stored key ID. This is
647
guaranteed by the fact that the client sends its public key in
648
the TLS handshake; this ensures it to be genuine. The server
649
computes the key ID of the key itself and looks up the key ID
650
in its list of clients. The <filename>clients.conf</filename>
526
652
<citerefentry><refentrytitle>mandos-clients.conf</refentrytitle>
527
653
<manvolnum>5</manvolnum></citerefentry>)
528
654
<emphasis>must</emphasis> be made non-readable by anyone
534
660
compromised if they are gone for too long.
537
If a client is compromised, its downtime should be duly noted
538
by the server which would therefore declare the client
539
invalid. But if the server was ever restarted, it would
540
re-read its client list from its configuration file and again
541
regard all clients therein as valid, and hence eligible to
542
receive their passwords. Therefore, be careful when
543
restarting servers if it is suspected that a client has, in
544
fact, been compromised by parties who may now be running a
545
fake Mandos client with the keys from the non-encrypted
546
initial <acronym>RAM</acronym> image of the client host. What
547
should be done in that case (if restarting the server program
548
really is necessary) is to stop the server program, edit the
549
configuration file to omit any suspect clients, and restart
553
663
For more details on client-side security, see
554
664
<citerefentry><refentrytitle>mandos-client</refentrytitle>
555
665
<manvolnum>8mandos</manvolnum></citerefentry>.
560
670
<refsect1 id="see_also">
561
671
<title>SEE ALSO</title>
564
<refentrytitle>mandos-clients.conf</refentrytitle>
565
<manvolnum>5</manvolnum></citerefentry>, <citerefentry>
566
<refentrytitle>mandos.conf</refentrytitle>
567
<manvolnum>5</manvolnum></citerefentry>, <citerefentry>
568
<refentrytitle>mandos-client</refentrytitle>
569
<manvolnum>8mandos</manvolnum></citerefentry>, <citerefentry>
570
<refentrytitle>sh</refentrytitle><manvolnum>1</manvolnum>
673
<citerefentry><refentrytitle>intro</refentrytitle>
674
<manvolnum>8mandos</manvolnum></citerefentry>,
675
<citerefentry><refentrytitle>mandos-clients.conf</refentrytitle>
676
<manvolnum>5</manvolnum></citerefentry>,
677
<citerefentry><refentrytitle>mandos.conf</refentrytitle>
678
<manvolnum>5</manvolnum></citerefentry>,
679
<citerefentry><refentrytitle>mandos-client</refentrytitle>
680
<manvolnum>8mandos</manvolnum></citerefentry>,
681
<citerefentry><refentrytitle>sh</refentrytitle>
682
<manvolnum>1</manvolnum></citerefentry>
664
RFC 5081: <citetitle>Using OpenPGP Keys for Transport Layer
669
This is implemented by GnuTLS and used by this server so
670
that OpenPGP keys can be used.
774
RFC 7250: <citetitle>Using Raw Public Keys in Transport
775
Layer Security (TLS) and Datagram Transport Layer Security
780
This is implemented by GnuTLS version 3.6.6 and is, if
781
present, used by this server so that raw public keys can be
788
RFC 6091: <citetitle>Using OpenPGP Keys for Transport Layer
789
Security (TLS) Authentication</citetitle>
793
This is implemented by GnuTLS before version 3.6.0 and is,
794
if present, used by this server so that OpenPGP keys can be
added
removed
mandos.xml
