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<command>&COMMANDNAME;</command>
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<arg choice="plain"><option>--connect
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<replaceable>ADDRESS</replaceable><literal>:</literal
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<replaceable>IPADDR</replaceable><literal>:</literal
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><replaceable>PORT</replaceable></option></arg>
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<arg choice="plain"><option>-c
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<replaceable>ADDRESS</replaceable><literal>:</literal
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<replaceable>IPADDR</replaceable><literal>:</literal
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><replaceable>PORT</replaceable></option></arg>
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<arg choice="plain"><option>--keydir
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<replaceable>DIRECTORY</replaceable></option></arg>
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<arg choice="plain"><option>-d
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<replaceable>DIRECTORY</replaceable></option></arg>
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<arg choice="plain"><option>--interface
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<replaceable>NAME</replaceable></option></arg>
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<arg choice="plain"><option>-i
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communicates with <citerefentry><refentrytitle
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>mandos</refentrytitle><manvolnum>8</manvolnum></citerefentry>
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to get a password. It uses IPv6 link-local addresses to get
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network connectivity, Zeroconf to find servers, and TLS with an
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OpenPGP key to ensure authenticity and confidentiality. It
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network connectivity, Zeroconf to find the server, and TLS with
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an OpenPGP key to ensure authenticity and confidentiality. It
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keeps running, trying all servers on the network, until it
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receives a satisfactory reply or a TERM signal is received.
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receives a satisfactory reply.
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This program is not meant to be run directly; it is really meant
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This program could, theoretically, be used as a keyscript in
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<filename>/etc/crypttab</filename>, but it would then be
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impossible to enter a password for the encrypted root disk at
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the console, since this program does not read from the console
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at all. This is why a separate plugin (<citerefentry>
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<refentrytitle>password-prompt</refentrytitle>
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<manvolnum>8mandos</manvolnum></citerefentry>) does that, which
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will be run in parallel to this one by the plugin runner.
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impossible to enter the encrypted root disk password at the
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console, since this program does not read from the console at
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all. This is why a separate plugin does that, which will be run
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in parallell to this one.
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<refsect1 id="file">
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<title>FILES</title>
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<term><filename>/conf/conf.d/mandos/pubkey.txt</filename
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<term><filename>/conf/conf.d/mandos/seckey.txt</filename
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OpenPGP public and private key files, in <quote>ASCII
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Armor</quote> format. These are the default file names,
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they can be changed with the <option>--pubkey</option> and
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<option>--seckey</option> options.
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<!-- <refsect1 id="bugs"> -->
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<!-- <title>BUGS</title> -->
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<refsect1 id="example">
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<title>EXAMPLE</title>
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Note that normally, command line options will not be given
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directly, but via options for the Mandos <citerefentry
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><refentrytitle>plugin-runner</refentrytitle>
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<manvolnum>8mandos</manvolnum></citerefentry>.
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Normal invocation needs no options, if the network interface
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is <quote>eth0</quote>:
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<userinput>&COMMANDNAME;</userinput>
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Search for Mandos servers (and connect to them) using another
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<!-- do not wrap this line -->
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<userinput>&COMMANDNAME; --interface eth1</userinput>
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Run in debug mode, and use a custom key:
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<!-- do not wrap this line -->
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<userinput>&COMMANDNAME; --debug --pubkey keydir/pubkey.txt --seckey keydir/seckey.txt</userinput>
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Run in debug mode, with a custom key, and do not use Zeroconf
411
to locate a server; connect directly to the IPv6 address
412
<quote><systemitem class="ipaddress"
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>2001:db8:f983:bd0b:30de:ae4a:71f2:f672</systemitem></quote>,
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port 4711, using interface eth2:
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<!-- do not wrap this line -->
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<userinput>&COMMANDNAME; --debug --pubkey keydir/pubkey.txt --seckey keydir/seckey.txt --connect 2001:db8:f983:bd0b:30de:ae4a:71f2:f672:4711 --interface eth2</userinput>
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<refsect1 id="security">
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381
<title>SECURITY</title>
428
This program is set-uid to root, but will switch back to the
429
original (and presumably non-privileged) user and group after
430
bringing up the network interface.
433
To use this program for its intended purpose (see <xref
434
linkend="purpose"/>), the password for the root file system will
435
have to be given out to be stored in a server computer, after
436
having been encrypted using an OpenPGP key. This encrypted data
437
which will be stored in a server can only be decrypted by the
438
OpenPGP key, and the data will only be given out to those
439
clients who can prove they actually have that key. This key,
440
however, is stored unencrypted on the client side in its initial
441
<acronym>RAM</acronym> disk image file system. This is normally
442
readable by all, but this is normally fixed during installation
443
of this program; file permissions are set so that no-one is able
447
The only remaining weak point is that someone with physical
448
access to the client hard drive might turn off the client
449
computer, read the OpenPGP keys directly from the hard drive,
450
and communicate with the server. The defense against this is
451
that the server is supposed to notice the client disappearing
452
and will stop giving out the encrypted data. Therefore, it is
453
important to set the timeout and checker interval values tightly
454
on the server. See <citerefentry><refentrytitle
455
>mandos</refentrytitle><manvolnum>8</manvolnum></citerefentry>.
458
It will also help if the checker program on the server is
459
configured to request something from the client which can not be
460
spoofed by someone else on the network, unlike unencrypted
461
<acronym>ICMP</acronym> echo (<quote>ping</quote>) replies.
464
<emphasis>Note</emphasis>: This makes it completely insecure to
465
have <application >Mandos</application> clients which dual-boot
466
to another operating system which is <emphasis>not</emphasis>
467
trusted to keep the initial <acronym>RAM</acronym> disk image
472
386
<refsect1 id="see_also">
473
387
<title>SEE ALSO</title>
475
<citerefentry><refentrytitle>cryptsetup</refentrytitle>
476
<manvolnum>8</manvolnum></citerefentry>,
477
<citerefentry><refentrytitle>crypttab</refentrytitle>
478
<manvolnum>5</manvolnum></citerefentry>,
479
389
<citerefentry><refentrytitle>mandos</refentrytitle>
480
390
<manvolnum>8</manvolnum></citerefentry>,
481
391
<citerefentry><refentrytitle>password-prompt</refentrytitle>
483
393
<citerefentry><refentrytitle>plugin-runner</refentrytitle>
484
394
<manvolnum>8mandos</manvolnum></citerefentry>
489
<ulink url="http://www.zeroconf.org/">Zeroconf</ulink>
493
Zeroconf is the network protocol standard used for finding
494
Mandos servers on the local network.
500
<ulink url="http://www.avahi.org/">Avahi</ulink>
504
Avahi is the library this program calls to find Zeroconf
511
<ulink url="http://www.gnu.org/software/gnutls/"
516
GnuTLS is the library this client uses to implement TLS for
517
communicating securely with the server, and at the same time
518
send the public OpenPGP key to the server.
524
<ulink url="http://www.gnupg.org/related_software/gpgme/"
529
GPGME is the library used to decrypt the OpenPGP data sent
536
RFC 4291: <citetitle>IP Version 6 Addressing
537
Architecture</citetitle>
542
<term>Section 2.2: <citetitle>Text Representation of
543
Addresses</citetitle></term>
544
<listitem><para/></listitem>
547
<term>Section 2.5.5.2: <citetitle>IPv4-Mapped IPv6
548
Address</citetitle></term>
549
<listitem><para/></listitem>
552
<term>Section 2.5.6, <citetitle>Link-Local IPv6 Unicast
553
Addresses</citetitle></term>
556
This client uses IPv6 link-local addresses, which are
557
immediately usable since a link-local addresses is
558
automatically assigned to a network interfaces when it
568
RFC 4346: <citetitle>The Transport Layer Security (TLS)
569
Protocol Version 1.1</citetitle>
573
TLS 1.1 is the protocol implemented by GnuTLS.
579
RFC 4880: <citetitle>OpenPGP Message Format</citetitle>
583
The data received from the server is binary encrypted
590
RFC 5081: <citetitle>Using OpenPGP Keys for Transport Layer
595
This is implemented by GnuTLS and used by this program so
596
that OpenPGP keys can be used.
398
<ulink url="http://www.zeroconf.org/">Zeroconf</ulink>
402
<ulink url="http://www.avahi.org/">Avahi</ulink>
407
url="http://www.gnu.org/software/gnutls/">GnuTLS</ulink>
412
url="http://www.gnupg.org/related_software/gpgme/"
417
<citation>RFC 4880: <citetitle>OpenPGP Message
418
Format</citetitle></citation>
422
<citation>RFC 5081: <citetitle>Using OpenPGP Keys for
423
Transport Layer Security</citetitle></citation>
427
<citation>RFC 4291: <citetitle>IP Version 6 Addressing
428
Architecture</citetitle>, section 2.5.6, Link-Local IPv6
429
Unicast Addresses</citation>