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<firstname>Björn</firstname>
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20
<surname>Påhlsson</surname>
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<email>belorn@fukt.bsnet.se</email>
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<email>belorn@recompile.se</email>
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<firstname>Teddy</firstname>
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<surname>Hogeborn</surname>
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<email>teddy@fukt.bsnet.se</email>
29
<email>teddy@recompile.se</email>
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<holder>Teddy Hogeborn</holder>
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46
<holder>Björn Påhlsson</holder>
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<replaceable>DIRECTORY</replaceable></option></arg>
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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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137
<command>&COMMANDNAME;</command> is a server daemon which
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138
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 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
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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
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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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<term><option>--no-dbus</option></term>
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<xi:include href="mandos-options.xml" xpointer="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
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look up (in a list read from <filename>clients.conf</filename>
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at start time) which binary blob to give the client. No other
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authentication or authorization is done by the server.
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The Mandos client must supply a TLS public key, and the key ID
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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)
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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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371
<title>Mandos Protocol (Version 1)</title><tgroup cols="3"><thead>
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The server will, by default, continually check that the clients
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414
are still up. If a client has not been confirmed as being up
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415
for some time, the client is assumed to be compromised and is no
308
longer eligible to receive the encrypted password. The timeout,
309
checker program, and interval between checks can be configured
310
both globally and per client; see <citerefentry>
416
longer eligible to receive the encrypted password. (Manual
417
intervention is required to re-enable a client.) The timeout,
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extended timeout, checker program, and interval between checks
419
can be configured both globally and per client; see
420
<citerefentry><refentrytitle>mandos-clients.conf</refentrytitle>
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<manvolnum>5</manvolnum></citerefentry>.
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<refsect1 id="approval">
426
<title>APPROVAL</title>
428
The server can be configured to require manual approval for a
429
client before it is sent its secret. The delay to wait for such
430
approval and the default action (approve or deny) can be
431
configured both globally and per client; see <citerefentry>
311
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<refentrytitle>mandos-clients.conf</refentrytitle>
312
<manvolnum>5</manvolnum></citerefentry>.
433
<manvolnum>5</manvolnum></citerefentry>. By default all clients
434
will be approved immediately without delay.
437
This can be used to deny a client its secret if not manually
438
approved within a specified time. It can also be used to make
439
the server delay before giving a client its secret, allowing
440
optional manual denying of this specific client.
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<refsect1 id="logging">
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<title>LOGGING</title>
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The server will send log message with various severity levels to
320
<filename>/dev/log</filename>. With the
449
<filename class="devicefile">/dev/log</filename>. With the
321
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<option>--debug</option> option, it will log even more messages,
322
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and also show them on the console.
455
<refsect1 id="persistent_state">
456
<title>PERSISTENT STATE</title>
458
Client settings, initially read from
459
<filename>clients.conf</filename>, are persistent across
460
restarts, and run-time changes will override settings in
461
<filename>clients.conf</filename>. However, if a setting is
462
<emphasis>changed</emphasis> (or a client added, or removed) in
463
<filename>clients.conf</filename>, this will take precedence.
467
<refsect1 id="dbus_interface">
468
<title>D-BUS INTERFACE</title>
470
The server will by default provide a D-Bus system bus interface.
471
This interface will only be accessible by the root user or a
472
Mandos-specific user, if such a user exists. For documentation
473
of the D-Bus API, see the file <filename>DBUS-API</filename>.
326
477
<refsect1 id="exit_status">
327
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<title>EXIT STATUS</title>
383
<term><filename>/var/run/mandos.pid</filename></term>
386
The file containing the process id of
387
<command>&COMMANDNAME;</command>.
392
<term><filename>/dev/log</filename></term>
534
<term><filename>/run/mandos.pid</filename></term>
537
The file containing the process id of the
538
<command>&COMMANDNAME;</command> process started last.
539
<emphasis >Note:</emphasis> If the <filename
540
class="directory">/run</filename> directory does not
541
exist, <filename>/var/run/mandos.pid</filename> will be
548
class="directory">/var/lib/mandos</filename></term>
551
Directory where persistent state will be saved. Change
552
this with the <option>--statedir</option> option. See
553
also the <option>--no-restore</option> option.
558
<term><filename class="devicefile">/dev/log</filename></term>
395
561
The Unix domain socket to where local syslog messages are
418
584
backtrace. This could be considered a feature.
421
Currently, if a client is declared <quote>invalid</quote> due to
422
having timed out, the server does not record this fact onto
423
permanent storage. This has some security implications, see
424
<xref linkend="clients"/>.
427
There is currently no way of querying the server of the current
428
status of clients, other than analyzing its <systemitem
429
class="service">syslog</systemitem> output.
432
587
There is no fine-grained control over logging and debug output.
435
Debug mode is conflated with running in the foreground.
438
The console log messages does not show a time stamp.
441
This server does not check the expire time of clients’ OpenPGP
589
<xi:include href="bugs.xml"/>
446
592
<refsect1 id="example">
456
602
<informalexample>
458
604
Run the server in debug mode, read configuration files from
459
the <filename>~/mandos</filename> directory, and use the
460
Zeroconf service name <quote>Test</quote> to not collide with
461
any other official Mandos server on this host:
605
the <filename class="directory">~/mandos</filename> directory,
606
and use the Zeroconf service name <quote>Test</quote> to not
607
collide with any other official Mandos server on this host:
496
642
<title>CLIENTS</title>
498
644
The server only gives out its stored data to clients which
499
does have the OpenPGP key of the stored fingerprint. This is
500
guaranteed by the fact that the client sends its OpenPGP
501
public key in the TLS handshake; this ensures it to be
502
genuine. The server computes the fingerprint of the key
503
itself and looks up the fingerprint in its list of
504
clients. The <filename>clients.conf</filename> file (see
645
does have the correct key ID of the stored key ID. This is
646
guaranteed by the fact that the client sends its public key in
647
the TLS handshake; this ensures it to be genuine. The server
648
computes the key ID of the key itself and looks up the key ID
649
in its list of clients. The <filename>clients.conf</filename>
505
651
<citerefentry><refentrytitle>mandos-clients.conf</refentrytitle>
506
652
<manvolnum>5</manvolnum></citerefentry>)
507
653
<emphasis>must</emphasis> be made non-readable by anyone
513
659
compromised if they are gone for too long.
516
If a client is compromised, its downtime should be duly noted
517
by the server which would therefore declare the client
518
invalid. But if the server was ever restarted, it would
519
re-read its client list from its configuration file and again
520
regard all clients therein as valid, and hence eligible to
521
receive their passwords. Therefore, be careful when
522
restarting servers if it is suspected that a client has, in
523
fact, been compromised by parties who may now be running a
524
fake Mandos client with the keys from the non-encrypted
525
initial <acronym>RAM</acronym> image of the client host. What
526
should be done in that case (if restarting the server program
527
really is necessary) is to stop the server program, edit the
528
configuration file to omit any suspect clients, and restart
532
662
For more details on client-side security, see
533
663
<citerefentry><refentrytitle>mandos-client</refentrytitle>
534
664
<manvolnum>8mandos</manvolnum></citerefentry>.
539
669
<refsect1 id="see_also">
540
670
<title>SEE ALSO</title>
543
<refentrytitle>mandos-clients.conf</refentrytitle>
544
<manvolnum>5</manvolnum></citerefentry>, <citerefentry>
545
<refentrytitle>mandos.conf</refentrytitle>
546
<manvolnum>5</manvolnum></citerefentry>, <citerefentry>
547
<refentrytitle>mandos-client</refentrytitle>
548
<manvolnum>8mandos</manvolnum></citerefentry>, <citerefentry>
549
<refentrytitle>sh</refentrytitle><manvolnum>1</manvolnum>
672
<citerefentry><refentrytitle>intro</refentrytitle>
673
<manvolnum>8mandos</manvolnum></citerefentry>,
674
<citerefentry><refentrytitle>mandos-clients.conf</refentrytitle>
675
<manvolnum>5</manvolnum></citerefentry>,
676
<citerefentry><refentrytitle>mandos.conf</refentrytitle>
677
<manvolnum>5</manvolnum></citerefentry>,
678
<citerefentry><refentrytitle>mandos-client</refentrytitle>
679
<manvolnum>8mandos</manvolnum></citerefentry>,
680
<citerefentry><refentrytitle>sh</refentrytitle>
681
<manvolnum>1</manvolnum></citerefentry>
643
RFC 5081: <citetitle>Using OpenPGP Keys for Transport Layer
648
This is implemented by GnuTLS and used by this server so
649
that OpenPGP keys can be used.
773
RFC 7250: <citetitle>Using Raw Public Keys in Transport
774
Layer Security (TLS) and Datagram Transport Layer Security
779
This is implemented by GnuTLS version 3.6.6 and is, if
780
present, used by this server so that raw public keys can be
787
RFC 6091: <citetitle>Using OpenPGP Keys for Transport Layer
788
Security (TLS) Authentication</citetitle>
792
This is implemented by GnuTLS before version 3.6.0 and is,
793
if present, used by this server so that OpenPGP keys can be
added
removed
mandos.xml
