2
2
<!DOCTYPE refentry PUBLIC "-//OASIS//DTD DocBook XML V4.5//EN"
3
3
"http://www.oasis-open.org/docbook/xml/4.5/docbookx.dtd" [
4
4
<!ENTITY COMMANDNAME "mandos-client">
5
<!ENTITY TIMESTAMP "2015-07-08">
5
<!ENTITY TIMESTAMP "2023-10-21">
6
6
<!ENTITY % common SYSTEM "../common.ent">
90
96
<replaceable>FILE</replaceable></option></arg>
100
<arg choice="plain"><option>--tls-privkey
101
<replaceable>FILE</replaceable></option></arg>
102
<arg choice="plain"><option>-t
103
<replaceable>FILE</replaceable></option></arg>
107
<arg choice="plain"><option>--tls-pubkey
108
<replaceable>FILE</replaceable></option></arg>
109
<arg choice="plain"><option>-T
110
<replaceable>FILE</replaceable></option></arg>
94
114
<option>--priority <replaceable>STRING</replaceable></option>
149
169
brings up network interfaces, uses the interfaces’ IPv6
150
170
link-local addresses to get network connectivity, uses Zeroconf
151
171
to find servers on the local network, and communicates with
152
servers using TLS with an OpenPGP key to ensure authenticity and
153
confidentiality. This client program keeps running, trying all
154
servers on the network, until it receives a satisfactory reply
155
or a TERM signal. After all servers have been tried, all
172
servers using TLS with a raw public key to ensure authenticity
173
and confidentiality. This client program keeps running, trying
174
all servers on the network, until it receives a satisfactory
175
reply or a TERM signal. After all servers have been tried, all
156
176
servers are periodically retried. If no servers are found it
157
177
will wait indefinitely for new servers to appear.
178
198
This program is not meant to be run directly; it is really meant
179
to run as a plugin of the <application>Mandos</application>
180
<citerefentry><refentrytitle>plugin-runner</refentrytitle>
181
<manvolnum>8mandos</manvolnum></citerefentry>, which runs in the
182
initial <acronym>RAM</acronym> disk environment because it is
183
specified as a <quote>keyscript</quote> in the <citerefentry>
184
<refentrytitle>crypttab</refentrytitle><manvolnum>5</manvolnum>
185
</citerefentry> file.
199
to be run by other programs in the initial
200
<acronym>RAM</acronym> disk environment; see <xref
201
linkend="overview"/>.
200
216
<title>OPTIONS</title>
202
218
This program is commonly not invoked from the command line; it
203
is normally started by the <application>Mandos</application>
204
plugin runner, see <citerefentry><refentrytitle
205
>plugin-runner</refentrytitle><manvolnum>8mandos</manvolnum>
206
</citerefentry>. Any command line options this program accepts
207
are therefore normally provided by the plugin runner, and not
219
is normally started by another program as described in <xref
220
linkend="description"/>. Any command line options this program
221
accepts are therefore normally provided by the invoking program,
319
<term><option>--tls-pubkey=<replaceable
320
>FILE</replaceable></option></term>
322
<replaceable>FILE</replaceable></option></term>
325
TLS raw public key file name. The default name is
326
<quote><filename>/conf/conf.d/mandos/tls-pubkey.pem</filename
333
<term><option>--tls-privkey=<replaceable
334
>FILE</replaceable></option></term>
336
<replaceable>FILE</replaceable></option></term>
339
TLS secret key file name. The default name is
340
<quote><filename>/conf/conf.d/mandos/tls-privkey.pem</filename
305
347
<term><option>--priority=<replaceable
306
348
>STRING</replaceable></option></term>
318
360
Sets the number of bits to use for the prime number in the
319
361
TLS Diffie-Hellman key exchange. The default value is
320
selected automatically based on the OpenPGP key. Note
321
that if the <option>--dh-params</option> option is used,
322
the values from that file will be used instead.
362
selected automatically based on the GnuTLS security
363
profile set in its priority string. Note that if the
364
<option>--dh-params</option> option is used, the values
365
from that file will be used instead.
433
476
<title>OVERVIEW</title>
434
477
<xi:include href="../overview.xml"/>
436
This program is the client part. It is a plugin started by
437
<citerefentry><refentrytitle>plugin-runner</refentrytitle>
438
<manvolnum>8mandos</manvolnum></citerefentry> which will run in
439
an initial <acronym>RAM</acronym> disk environment.
479
This program is the client part. It is run automatically in an
480
initial <acronym>RAM</acronym> disk environment.
483
In an initial <acronym>RAM</acronym> disk environment using
484
<citerefentry><refentrytitle>systemd</refentrytitle>
485
<manvolnum>1</manvolnum></citerefentry>, this program is started
486
by the <application>Mandos</application> <citerefentry>
487
<refentrytitle>password-agent</refentrytitle>
488
<manvolnum>8mandos</manvolnum></citerefentry>, which in turn is
489
started automatically by the <citerefentry>
490
<refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum>
491
</citerefentry> <quote>Password Agent</quote> system.
494
In the case of a non-<citerefentry>
495
<refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum>
496
</citerefentry> environment, this program is started as a plugin
497
of the <application>Mandos</application> <citerefentry>
498
<refentrytitle>plugin-runner</refentrytitle>
499
<manvolnum>8mandos</manvolnum></citerefentry>, which runs in the
500
initial <acronym>RAM</acronym> disk environment because it is
501
specified as a <quote>keyscript</quote> in the <citerefentry>
502
<refentrytitle>crypttab</refentrytitle><manvolnum>5</manvolnum>
503
</citerefentry> file.
442
506
This program could, theoretically, be used as a keyscript in
443
507
<filename>/etc/crypttab</filename>, but it would then be
444
508
impossible to enter a password for the encrypted root disk at
445
509
the console, since this program does not read from the console
446
at all. This is why a separate plugin runner (<citerefentry>
447
<refentrytitle>plugin-runner</refentrytitle>
448
<manvolnum>8mandos</manvolnum></citerefentry>) is used to run
449
both this program and others in in parallel,
450
<emphasis>one</emphasis> of which (<citerefentry>
451
<refentrytitle>password-prompt</refentrytitle>
452
<manvolnum>8mandos</manvolnum></citerefentry>) will prompt for
453
passwords on the system console.
477
534
This environment variable will be assumed to contain the
478
535
directory containing any helper executables. The use and
479
nature of these helper executables, if any, is
480
purposefully not documented.
536
nature of these helper executables, if any, is purposely
737
<term><filename>/conf/conf.d/mandos/tls-pubkey.pem</filename
739
<term><filename>/conf/conf.d/mandos/tls-privkey.pem</filename
743
Public and private raw key files, in <quote>PEM</quote>
744
format. These are the default file names, they can be
745
changed with the <option>--tls-pubkey</option> and
746
<option>--tls-privkey</option> options.
681
752
class="directory">/lib/mandos/network-hooks.d</filename></term>
693
<!-- <refsect1 id="bugs"> -->
694
<!-- <title>BUGS</title> -->
766
<xi:include href="../bugs.xml"/>
699
769
<refsect1 id="example">
700
770
<title>EXAMPLE</title>
702
772
Note that normally, command line options will not be given
703
directly, but via options for the Mandos <citerefentry
704
><refentrytitle>plugin-runner</refentrytitle>
705
<manvolnum>8mandos</manvolnum></citerefentry>.
773
directly, but passed on via the program responsible for starting
774
this program; see <xref linkend="overview"/>.
707
776
<informalexample>
725
794
</informalexample>
726
795
<informalexample>
728
Run in debug mode, and use a custom key:
797
Run in debug mode, and use custom keys:
732
801
<!-- do not wrap this line -->
733
<userinput>&COMMANDNAME; --debug --pubkey keydir/pubkey.txt --seckey keydir/seckey.txt</userinput>
802
<userinput>&COMMANDNAME; --debug --pubkey keydir/pubkey.txt --seckey keydir/seckey.txt --tls-pubkey keydir/tls-pubkey.pem --tls-privkey keydir/tls-privkey.pem</userinput>
736
805
</informalexample>
737
806
<informalexample>
739
Run in debug mode, with a custom key, and do not use Zeroconf
808
Run in debug mode, with custom keys, and do not use Zeroconf
740
809
to locate a server; connect directly to the IPv6 link-local
741
810
address <quote><systemitem class="ipaddress"
742
811
>fe80::aede:48ff:fe71:f6f2</systemitem></quote>, port 4711,
754
823
<refsect1 id="security">
755
824
<title>SECURITY</title>
757
This program is set-uid to root, but will switch back to the
758
original (and presumably non-privileged) user and group after
759
bringing up the network interface.
826
This program assumes that it is set-uid to root, and will switch
827
back to the original (and presumably non-privileged) user and
828
group after bringing up the network interface.
762
831
To use this program for its intended purpose (see <xref
776
845
The only remaining weak point is that someone with physical
777
846
access to the client hard drive might turn off the client
778
computer, read the OpenPGP keys directly from the hard drive,
779
and communicate with the server. To safeguard against this, the
780
server is supposed to notice the client disappearing and stop
781
giving out the encrypted data. Therefore, it is important to
782
set the timeout and checker interval values tightly on the
783
server. See <citerefentry><refentrytitle
847
computer, read the OpenPGP and TLS keys directly from the hard
848
drive, and communicate with the server. To safeguard against
849
this, the server is supposed to notice the client disappearing
850
and stop giving out the encrypted data. Therefore, it is
851
important to set the timeout and checker interval values tightly
852
on the server. See <citerefentry><refentrytitle
784
853
>mandos</refentrytitle><manvolnum>8</manvolnum></citerefentry>.
810
879
<manvolnum>5</manvolnum></citerefentry>,
811
880
<citerefentry><refentrytitle>mandos</refentrytitle>
812
881
<manvolnum>8</manvolnum></citerefentry>,
813
<citerefentry><refentrytitle>password-prompt</refentrytitle>
882
<citerefentry><refentrytitle>password-agent</refentrytitle>
814
883
<manvolnum>8mandos</manvolnum></citerefentry>,
815
884
<citerefentry><refentrytitle>plugin-runner</refentrytitle>
816
885
<manvolnum>8mandos</manvolnum></citerefentry>
843
<ulink url="http://www.gnu.org/software/gnutls/"
912
<ulink url="https://www.gnutls.org/">GnuTLS</ulink>
848
916
GnuTLS is the library this client uses to implement TLS for
849
917
communicating securely with the server, and at the same time
850
send the public OpenPGP key to the server.
918
send the public key to the server.
856
<ulink url="http://www.gnupg.org/related_software/gpgme/"
924
<ulink url="https://www.gnupg.org/related_software/gpgme/"
900
RFC 4346: <citetitle>The Transport Layer Security (TLS)
901
Protocol Version 1.1</citetitle>
968
RFC 5246: <citetitle>The Transport Layer Security (TLS)
969
Protocol Version 1.2</citetitle>
905
TLS 1.1 is the protocol implemented by GnuTLS.
973
TLS 1.2 is the protocol implemented by GnuTLS.
922
RFC 5081: <citetitle>Using OpenPGP Keys for Transport Layer
990
RFC 7250: <citetitle>Using Raw Public Keys in Transport
991
Layer Security (TLS) and Datagram Transport Layer Security
996
This is implemented by GnuTLS in version 3.6.6 and is, if
997
present, used by this program so that raw public keys can be
1004
RFC 6091: <citetitle>Using OpenPGP Keys for Transport Layer
923
1005
Security</citetitle>
927
This is implemented by GnuTLS and used by this program so
928
that OpenPGP keys can be used.
1009
This is implemented by GnuTLS before version 3.6.0 and is,
1010
if present, used by this program so that OpenPGP keys can be