64
73
><replaceable>PORT</replaceable></option></arg>
68
77
<arg choice="plain"><option>--interface
69
<replaceable>NAME</replaceable></option></arg>
70
<arg choice="plain"><option>-i
71
<replaceable>NAME</replaceable></option></arg>
78
<replaceable>NAME</replaceable><arg rep='repeat'
79
>,<replaceable>NAME</replaceable></arg></option></arg>
80
<arg choice="plain"><option>-i <replaceable>NAME</replaceable
81
><arg rep='repeat'>,<replaceable>NAME</replaceable></arg
85
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>
89
114
<option>--priority <replaceable>STRING</replaceable></option>
137
166
communicates with <citerefentry><refentrytitle
138
167
>mandos</refentrytitle><manvolnum>8</manvolnum></citerefentry>
139
168
to get a password. In slightly more detail, this client program
140
brings up a network interface, uses the interface’s IPv6
141
link-local address to get network connectivity, uses Zeroconf to
142
find servers on the local network, and communicates with servers
143
using TLS with an OpenPGP key to ensure authenticity and
144
confidentiality. This client program keeps running, trying all
145
servers on the network, until it receives a satisfactory reply
146
or a TERM signal. After all servers have been tried, all
169
brings up network interfaces, uses the interfaces’ IPv6
170
link-local addresses to get network connectivity, uses Zeroconf
171
to find servers on the local network, and communicates with
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
147
176
servers are periodically retried. If no servers are found it
148
177
will wait indefinitely for new servers to appear.
151
The network interface is selected like this: If an interface is
152
specified using the <option>--interface</option> option, that
153
interface is used. Otherwise, <command>&COMMANDNAME;</command>
154
will choose any interface that is up and running and is not a
155
loopback interface, is not a point-to-point interface, is
156
capable of broadcasting and does not have the NOARP flag (see
180
The network interfaces are selected like this: If any interfaces
181
are specified using the <option>--interface</option> option,
182
those interface are used. Otherwise,
183
<command>&COMMANDNAME;</command> will use all interfaces that
184
are not loopback interfaces, are not point-to-point interfaces,
185
are capable of broadcasting and do not have the NOARP flag (see
157
186
<citerefentry><refentrytitle>netdevice</refentrytitle>
158
187
<manvolnum>7</manvolnum></citerefentry>). (If the
159
188
<option>--connect</option> option is used, point-to-point
160
interfaces and non-broadcast interfaces are accepted.) If no
161
acceptable interfaces are found, re-run the check but without
162
the <quote>up and running</quote> requirement, and manually take
163
the selected interface up (and later take it down on program
189
interfaces and non-broadcast interfaces are accepted.) If any
190
used interfaces are not up and running, they are first taken up
191
(and later taken down again on program exit).
167
Before a network interface is selected, all <quote>network
194
Before network interfaces are selected, all <quote>network
168
195
hooks</quote> are run; see <xref linkend="network-hooks"/>.
218
245
assumed to separate the address from the port number.
221
This option is normally only useful for testing and
248
Normally, Zeroconf would be used to locate Mandos servers,
249
in which case this option would only be used when testing
228
256
<term><option>--interface=<replaceable
229
>NAME</replaceable></option></term>
257
>NAME</replaceable><arg rep='repeat'>,<replaceable
258
>NAME</replaceable></arg></option></term>
231
<replaceable>NAME</replaceable></option></term>
260
<replaceable>NAME</replaceable><arg rep='repeat'>,<replaceable
261
>NAME</replaceable></arg></option></term>
234
Network interface that will be brought up and scanned for
235
Mandos servers to connect to. The default is the empty
236
string, which will automatically choose an appropriate
264
Comma separated list of network interfaces that will be
265
brought up and scanned for Mandos servers to connect to.
266
The default is the empty string, which will automatically
267
use all appropriate interfaces.
240
If the <option>--connect</option> option is used, this
241
specifies the interface to use to connect to the address
270
If the <option>--connect</option> option is used, and
271
exactly one interface name is specified (except
272
<quote><literal>none</literal></quote>), this specifies
273
the interface to use to connect to the address given.
245
276
Note that since this program will normally run in the
246
277
initial RAM disk environment, the interface must be an
247
278
interface which exists at that stage. Thus, the interface
248
can not be a pseudo-interface such as <quote>br0</quote>
249
or <quote>tun0</quote>; such interfaces will not exist
250
until much later in the boot process, and can not be used
251
by this program, unless created by a <quote>network
252
hook</quote> — see <xref linkend="network-hooks"/>.
279
can normally not be a pseudo-interface such as
280
<quote>br0</quote> or <quote>tun0</quote>; such interfaces
281
will not exist until much later in the boot process, and
282
can not be used by this program, unless created by a
283
<quote>network hook</quote> — see <xref
284
linkend="network-hooks"/>.
255
287
<replaceable>NAME</replaceable> can be the string
256
<quote><literal>none</literal></quote>; this will not use
257
any specific interface, and will not bring up an interface
258
on startup. This is not recommended, and only meant for
288
<quote><literal>none</literal></quote>; this will make
289
<command>&COMMANDNAME;</command> only bring up interfaces
290
specified <emphasis>before</emphasis> this string. This
291
is not recommended, and only meant for advanced users.
325
<term><option>--tls-pubkey=<replaceable
326
>FILE</replaceable></option></term>
328
<replaceable>FILE</replaceable></option></term>
331
TLS raw public key file name. The default name is
332
<quote><filename>/conf/conf.d/mandos/tls-pubkey.pem</filename
339
<term><option>--tls-privkey=<replaceable
340
>FILE</replaceable></option></term>
342
<replaceable>FILE</replaceable></option></term>
345
TLS secret key file name. The default name is
346
<quote><filename>/conf/conf.d/mandos/tls-privkey.pem</filename
293
353
<term><option>--priority=<replaceable
294
354
>STRING</replaceable></option></term>
306
366
Sets the number of bits to use for the prime number in the
307
TLS Diffie-Hellman key exchange. Default is 1024.
367
TLS Diffie-Hellman key exchange. The default value is
368
selected automatically based on the GnuTLS security
369
profile set in its priority string. Note that if the
370
<option>--dh-params</option> option is used, the values
371
from that file will be used instead.
377
<term><option>--dh-params=<replaceable
378
>FILE</replaceable></option></term>
381
Specifies a PEM-encoded PKCS#3 file to read the parameters
382
needed by the TLS Diffie-Hellman key exchange from. If
383
this option is not given, or if the file for some reason
384
could not be used, the parameters will be generated on
385
startup, which will take some time and processing power.
386
Those using servers running under time, power or processor
387
constraints may want to generate such a file in advance
438
519
<refsect1 id="environment">
439
520
<title>ENVIRONMENT</title>
523
<term><envar>MANDOSPLUGINHELPERDIR</envar></term>
526
This environment variable will be assumed to contain the
527
directory containing any helper executables. The use and
528
nature of these helper executables, if any, is purposely
441
This program does not use any environment variables, not even
442
the ones provided by <citerefentry><refentrytitle
535
This program does not use any other environment variables, not
536
even the ones provided by <citerefentry><refentrytitle
443
537
>cryptsetup</refentrytitle><manvolnum>8</manvolnum>
497
591
<term><literal>files</literal></term>
500
This should make the network hook print, <emphasis>on
501
separate lines</emphasis>, all the files needed for it
502
to run. (These files will be copied into the initial
503
RAM filesystem.) Intended use is for a network hook
504
which is a shell script to print its needed binaries.
594
This should make the network hook print, <emphasis>one
595
file per line</emphasis>, all the files needed for it to
596
run. (These files will be copied into the initial RAM
597
filesystem.) Typical use is for a network hook which is
598
a shell script to print its needed binaries.
507
601
It is not necessary to print any non-executable files
508
602
already in the network hook directory, these will be
509
603
copied implicitly if they otherwise satisfy the name
609
<term><literal>modules</literal></term>
612
This should make the network hook print, <emphasis>on
613
separate lines</emphasis>, all the kernel modules needed
614
for it to run. (These modules will be copied into the
615
initial RAM filesystem.) For instance, a tunnel
617
<quote><literal>tun</literal></quote> module.
534
641
<term><envar>DEVICE</envar></term>
537
The network interface, as specified to
644
The network interfaces, as specified to
538
645
<command>&COMMANDNAME;</command> by the
539
<option>--interface</option> option. If this is not the
540
interface a hook will bring up, there is no reason for a
646
<option>--interface</option> option, combined to one
647
string and separated by commas. If this is set, and
648
does not contain the interface a hook will bring up,
649
there is no reason for a hook to continue.
549
657
This will be the same as the first argument;
550
658
i.e. <quote><literal>start</literal></quote>,
551
<quote><literal>stop</literal></quote>, or
552
<quote><literal>files</literal></quote>.
659
<quote><literal>stop</literal></quote>,
660
<quote><literal>files</literal></quote>, or
661
<quote><literal>modules</literal></quote>.
571
680
This will be the same as the <option>--delay</option>
572
option passed to <command>&COMMANDNAME;</command>.
681
option passed to <command>&COMMANDNAME;</command>. Is
682
only set if <envar>MODE</envar> is
683
<quote><literal>start</literal></quote> or
684
<quote><literal>stop</literal></quote>.
689
<term><envar>CONNECT</envar></term>
692
This will be the same as the <option>--connect</option>
693
option passed to <command>&COMMANDNAME;</command>. Is
694
only set if <option>--connect</option> is passed and
695
<envar>MODE</envar> is
696
<quote><literal>start</literal></quote> or
697
<quote><literal>stop</literal></quote>.
649
787
</informalexample>
650
788
<informalexample>
652
Run in debug mode, and use a custom key:
790
Run in debug mode, and use custom keys:
656
794
<!-- do not wrap this line -->
657
<userinput>&COMMANDNAME; --debug --pubkey keydir/pubkey.txt --seckey keydir/seckey.txt</userinput>
795
<userinput>&COMMANDNAME; --debug --pubkey keydir/pubkey.txt --seckey keydir/seckey.txt --tls-pubkey keydir/tls-pubkey.pem --tls-privkey keydir/tls-privkey.pem</userinput>
660
798
</informalexample>
661
799
<informalexample>
663
Run in debug mode, with a custom key, and do not use Zeroconf
801
Run in debug mode, with custom keys, and do not use Zeroconf
664
802
to locate a server; connect directly to the IPv6 link-local
665
803
address <quote><systemitem class="ipaddress"
666
804
>fe80::aede:48ff:fe71:f6f2</systemitem></quote>, port 4711,
700
838
The only remaining weak point is that someone with physical
701
839
access to the client hard drive might turn off the client
702
computer, read the OpenPGP keys directly from the hard drive,
703
and communicate with the server. To safeguard against this, the
704
server is supposed to notice the client disappearing and stop
705
giving out the encrypted data. Therefore, it is important to
706
set the timeout and checker interval values tightly on the
707
server. See <citerefentry><refentrytitle
840
computer, read the OpenPGP and TLS keys directly from the hard
841
drive, and communicate with the server. To safeguard against
842
this, the server is supposed to notice the client disappearing
843
and stop giving out the encrypted data. Therefore, it is
844
important to set the timeout and checker interval values tightly
845
on the server. See <citerefentry><refentrytitle
708
846
>mandos</refentrytitle><manvolnum>8</manvolnum></citerefentry>.
711
849
It will also help if the checker program on the server is
712
850
configured to request something from the client which can not be
713
spoofed by someone else on the network, unlike unencrypted
714
<acronym>ICMP</acronym> echo (<quote>ping</quote>) replies.
851
spoofed by someone else on the network, like SSH server key
852
fingerprints, and unlike unencrypted <acronym>ICMP</acronym>
853
echo (<quote>ping</quote>) replies.
717
856
<emphasis>Note</emphasis>: This makes it completely insecure to
766
<ulink url="http://www.gnu.org/software/gnutls/"
905
<ulink url="https://www.gnutls.org/">GnuTLS</ulink>
771
909
GnuTLS is the library this client uses to implement TLS for
772
910
communicating securely with the server, and at the same time
773
send the public OpenPGP key to the server.
911
send the public key to the server.
779
<ulink url="http://www.gnupg.org/related_software/gpgme/"
917
<ulink url="https://www.gnupg.org/related_software/gpgme/"
845
RFC 5081: <citetitle>Using OpenPGP Keys for Transport Layer
983
RFC 7250: <citetitle>Using Raw Public Keys in Transport
984
Layer Security (TLS) and Datagram Transport Layer Security
989
This is implemented by GnuTLS in version 3.6.6 and is, if
990
present, used by this program so that raw public keys can be
997
RFC 6091: <citetitle>Using OpenPGP Keys for Transport Layer
846
998
Security</citetitle>
850
This is implemented by GnuTLS and used by this program so
851
that OpenPGP keys can be used.
1002
This is implemented by GnuTLS before version 3.6.0 and is,
1003
if present, used by this program so that OpenPGP keys can be