64
72
><replaceable>PORT</replaceable></option></arg>
68
76
<arg choice="plain"><option>--interface
69
<replaceable>NAME</replaceable></option></arg>
70
<arg choice="plain"><option>-i
71
<replaceable>NAME</replaceable></option></arg>
77
<replaceable>NAME</replaceable><arg rep='repeat'
78
>,<replaceable>NAME</replaceable></arg></option></arg>
79
<arg choice="plain"><option>-i <replaceable>NAME</replaceable
80
><arg rep='repeat'>,<replaceable>NAME</replaceable></arg
85
95
<replaceable>FILE</replaceable></option></arg>
99
<arg choice="plain"><option>--tls-privkey
100
<replaceable>FILE</replaceable></option></arg>
101
<arg choice="plain"><option>-t
102
<replaceable>FILE</replaceable></option></arg>
106
<arg choice="plain"><option>--tls-pubkey
107
<replaceable>FILE</replaceable></option></arg>
108
<arg choice="plain"><option>-T
109
<replaceable>FILE</replaceable></option></arg>
89
113
<option>--priority <replaceable>STRING</replaceable></option>
137
165
communicates with <citerefentry><refentrytitle
138
166
>mandos</refentrytitle><manvolnum>8</manvolnum></citerefentry>
139
167
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
168
brings up network interfaces, uses the interfaces’ IPv6
169
link-local addresses to get network connectivity, uses Zeroconf
170
to find servers on the local network, and communicates with
171
servers using TLS with a raw public key to ensure authenticity
172
and confidentiality. This client program keeps running, trying
173
all servers on the network, until it receives a satisfactory
174
reply or a TERM signal. After all servers have been tried, all
147
175
servers are periodically retried. If no servers are found it
148
176
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
179
The network interfaces are selected like this: If any interfaces
180
are specified using the <option>--interface</option> option,
181
those interface are used. Otherwise,
182
<command>&COMMANDNAME;</command> will use all interfaces that
183
are not loopback interfaces, are not point-to-point interfaces,
184
are capable of broadcasting and do not have the NOARP flag (see
157
185
<citerefentry><refentrytitle>netdevice</refentrytitle>
158
186
<manvolnum>7</manvolnum></citerefentry>). (If the
159
187
<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
188
interfaces and non-broadcast interfaces are accepted.) If any
189
used interfaces are not up and running, they are first taken up
190
(and later taken down again on program exit).
167
Before a network interface is selected, all <quote>network
193
Before network interfaces are selected, all <quote>network
168
194
hooks</quote> are run; see <xref linkend="network-hooks"/>.
218
244
assumed to separate the address from the port number.
221
This option is normally only useful for testing and
247
Normally, Zeroconf would be used to locate Mandos servers,
248
in which case this option would only be used when testing
228
255
<term><option>--interface=<replaceable
229
>NAME</replaceable></option></term>
256
>NAME</replaceable><arg rep='repeat'>,<replaceable
257
>NAME</replaceable></arg></option></term>
231
<replaceable>NAME</replaceable></option></term>
259
<replaceable>NAME</replaceable><arg rep='repeat'>,<replaceable
260
>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
263
Comma separated list of network interfaces that will be
264
brought up and scanned for Mandos servers to connect to.
265
The default is the empty string, which will automatically
266
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
269
If the <option>--connect</option> option is used, and
270
exactly one interface name is specified (except
271
<quote><literal>none</literal></quote>), this specifies
272
the interface to use to connect to the address given.
245
275
Note that since this program will normally run in the
246
276
initial RAM disk environment, the interface must be an
247
277
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"/>.
278
can normally not be a pseudo-interface such as
279
<quote>br0</quote> or <quote>tun0</quote>; such interfaces
280
will not exist until much later in the boot process, and
281
can not be used by this program, unless created by a
282
<quote>network hook</quote> — see <xref
283
linkend="network-hooks"/>.
255
286
<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
287
<quote><literal>none</literal></quote>; this will make
288
<command>&COMMANDNAME;</command> only bring up interfaces
289
specified <emphasis>before</emphasis> this string. This
290
is not recommended, and only meant for advanced users.
324
<term><option>--tls-pubkey=<replaceable
325
>FILE</replaceable></option></term>
327
<replaceable>FILE</replaceable></option></term>
330
TLS raw public key file name. The default name is
331
<quote><filename>/conf/conf.d/mandos/tls-pubkey.pem</filename
338
<term><option>--tls-privkey=<replaceable
339
>FILE</replaceable></option></term>
341
<replaceable>FILE</replaceable></option></term>
344
TLS secret key file name. The default name is
345
<quote><filename>/conf/conf.d/mandos/tls-privkey.pem</filename
293
352
<term><option>--priority=<replaceable
294
353
>STRING</replaceable></option></term>
306
365
Sets the number of bits to use for the prime number in the
307
TLS Diffie-Hellman key exchange. Default is 1024.
366
TLS Diffie-Hellman key exchange. The default value is
367
selected automatically based on the GnuTLS security
368
profile set in its priority string. Note that if the
369
<option>--dh-params</option> option is used, the values
370
from that file will be used instead.
376
<term><option>--dh-params=<replaceable
377
>FILE</replaceable></option></term>
380
Specifies a PEM-encoded PKCS#3 file to read the parameters
381
needed by the TLS Diffie-Hellman key exchange from. If
382
this option is not given, or if the file for some reason
383
could not be used, the parameters will be generated on
384
startup, which will take some time and processing power.
385
Those using servers running under time, power or processor
386
constraints may want to generate such a file in advance
438
518
<refsect1 id="environment">
439
519
<title>ENVIRONMENT</title>
522
<term><envar>MANDOSPLUGINHELPERDIR</envar></term>
525
This environment variable will be assumed to contain the
526
directory containing any helper executables. The use and
527
nature of these helper executables, if any, is
528
purposefully not documented.
441
This program does not use any environment variables, not even
442
the ones provided by <citerefentry><refentrytitle
534
This program does not use any other environment variables, not
535
even the ones provided by <citerefentry><refentrytitle
443
536
>cryptsetup</refentrytitle><manvolnum>8</manvolnum>
497
590
<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.
593
This should make the network hook print, <emphasis>one
594
file per line</emphasis>, all the files needed for it to
595
run. (These files will be copied into the initial RAM
596
filesystem.) Typical use is for a network hook which is
597
a shell script to print its needed binaries.
507
600
It is not necessary to print any non-executable files
508
601
already in the network hook directory, these will be
509
602
copied implicitly if they otherwise satisfy the name
608
<term><literal>modules</literal></term>
611
This should make the network hook print, <emphasis>on
612
separate lines</emphasis>, all the kernel modules needed
613
for it to run. (These modules will be copied into the
614
initial RAM filesystem.) For instance, a tunnel
616
<quote><literal>tun</literal></quote> module.
534
640
<term><envar>DEVICE</envar></term>
537
The network interface, as specified to
643
The network interfaces, as specified to
538
644
<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
645
<option>--interface</option> option, combined to one
646
string and separated by commas. If this is set, and
647
does not contain the interface a hook will bring up,
648
there is no reason for a hook to continue.
549
656
This will be the same as the first argument;
550
657
i.e. <quote><literal>start</literal></quote>,
551
<quote><literal>stop</literal></quote>, or
552
<quote><literal>files</literal></quote>.
658
<quote><literal>stop</literal></quote>,
659
<quote><literal>files</literal></quote>, or
660
<quote><literal>modules</literal></quote>.
571
679
This will be the same as the <option>--delay</option>
572
option passed to <command>&COMMANDNAME;</command>.
680
option passed to <command>&COMMANDNAME;</command>. Is
681
only set if <envar>MODE</envar> is
682
<quote><literal>start</literal></quote> or
683
<quote><literal>stop</literal></quote>.
688
<term><envar>CONNECT</envar></term>
691
This will be the same as the <option>--connect</option>
692
option passed to <command>&COMMANDNAME;</command>. Is
693
only set if <option>--connect</option> is passed and
694
<envar>MODE</envar> is
695
<quote><literal>start</literal></quote> or
696
<quote><literal>stop</literal></quote>.
649
786
</informalexample>
650
787
<informalexample>
652
Run in debug mode, and use a custom key:
789
Run in debug mode, and use custom keys:
656
793
<!-- do not wrap this line -->
657
<userinput>&COMMANDNAME; --debug --pubkey keydir/pubkey.txt --seckey keydir/seckey.txt</userinput>
794
<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
797
</informalexample>
661
798
<informalexample>
663
Run in debug mode, with a custom key, and do not use Zeroconf
800
Run in debug mode, with custom keys, and do not use Zeroconf
664
801
to locate a server; connect directly to the IPv6 link-local
665
802
address <quote><systemitem class="ipaddress"
666
803
>fe80::aede:48ff:fe71:f6f2</systemitem></quote>, port 4711,
700
837
The only remaining weak point is that someone with physical
701
838
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
839
computer, read the OpenPGP and TLS keys directly from the hard
840
drive, and communicate with the server. To safeguard against
841
this, the server is supposed to notice the client disappearing
842
and stop giving out the encrypted data. Therefore, it is
843
important to set the timeout and checker interval values tightly
844
on the server. See <citerefentry><refentrytitle
708
845
>mandos</refentrytitle><manvolnum>8</manvolnum></citerefentry>.
711
848
It will also help if the checker program on the server is
712
849
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.
850
spoofed by someone else on the network, like SSH server key
851
fingerprints, and unlike unencrypted <acronym>ICMP</acronym>
852
echo (<quote>ping</quote>) replies.
717
855
<emphasis>Note</emphasis>: This makes it completely insecure to
766
<ulink url="http://www.gnu.org/software/gnutls/"
904
<ulink url="https://www.gnutls.org/">GnuTLS</ulink>
771
908
GnuTLS is the library this client uses to implement TLS for
772
909
communicating securely with the server, and at the same time
773
send the public OpenPGP key to the server.
910
send the public key to the server.
779
<ulink url="http://www.gnupg.org/related_software/gpgme/"
916
<ulink url="https://www.gnupg.org/related_software/gpgme/"
845
RFC 5081: <citetitle>Using OpenPGP Keys for Transport Layer
982
RFC 7250: <citetitle>Using Raw Public Keys in Transport
983
Layer Security (TLS) and Datagram Transport Layer Security
988
This is implemented by GnuTLS in version 3.6.6 and is, if
989
present, used by this program so that raw public keys can be
996
RFC 6091: <citetitle>Using OpenPGP Keys for Transport Layer
846
997
Security</citetitle>
850
This is implemented by GnuTLS and used by this program so
851
that OpenPGP keys can be used.
1001
This is implemented by GnuTLS before version 3.6.0 and is,
1002
if present, used by this program so that OpenPGP keys can be