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 "2014-03-01">
5
<!ENTITY TIMESTAMP "2019-02-09">
6
6
<!ENTITY % common SYSTEM "../common.ent">
89
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>
93
113
<option>--priority <replaceable>STRING</replaceable></option>
144
168
brings up network interfaces, uses the interfaces’ IPv6
145
169
link-local addresses to get network connectivity, uses Zeroconf
146
170
to find servers on the local network, and communicates with
147
servers using TLS with an OpenPGP key to ensure authenticity and
148
confidentiality. This client program keeps running, trying all
149
servers on the network, until it receives a satisfactory reply
150
or a TERM signal. After all servers have been tried, all
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
151
175
servers are periodically retried. If no servers are found it
152
176
will wait indefinitely for new servers to appear.
262
286
<replaceable>NAME</replaceable> can be the string
263
287
<quote><literal>none</literal></quote>; this will make
264
<command>&COMMANDNAME;</command> not bring up
265
<emphasis>any</emphasis> interfaces specified
266
<emphasis>after</emphasis> this string. This is not
267
recommended, and only meant for advanced users.
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
301
352
<term><option>--priority=<replaceable
302
353
>STRING</replaceable></option></term>
314
365
Sets the number of bits to use for the prime number in the
315
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
446
518
<refsect1 id="environment">
447
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.
449
This program does not use any environment variables, not even
450
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
451
536
>cryptsetup</refentrytitle><manvolnum>8</manvolnum>
728
<term><filename>/conf/conf.d/mandos/tls-pubkey.pem</filename
730
<term><filename>/conf/conf.d/mandos/tls-privkey.pem</filename
734
Public and private raw key files, in <quote>PEM</quote>
735
format. These are the default file names, they can be
736
changed with the <option>--tls-pubkey</option> and
737
<option>--tls-privkey</option> options.
644
743
class="directory">/lib/mandos/network-hooks.d</filename></term>
688
786
</informalexample>
689
787
<informalexample>
691
Run in debug mode, and use a custom key:
789
Run in debug mode, and use custom keys:
695
793
<!-- do not wrap this line -->
696
<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>
699
797
</informalexample>
700
798
<informalexample>
702
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
703
801
to locate a server; connect directly to the IPv6 link-local
704
802
address <quote><systemitem class="ipaddress"
705
803
>fe80::aede:48ff:fe71:f6f2</systemitem></quote>, port 4711,
710
808
<!-- do not wrap this line -->
711
<userinput>&COMMANDNAME; --debug --pubkey keydir/pubkey.txt --seckey keydir/seckey.txt --connect fe80::aede:48ff:fe71:f6f2:4711 --interface eth2</userinput>
809
<userinput>&COMMANDNAME; --debug --pubkey keydir/pubkey.txt --seckey keydir/seckey.txt --tls-pubkey keydir/tls-pubkey.pem --tls-privkey keydir/tls-privkey.pem --connect fe80::aede:48ff:fe71:f6f2:4711 --interface eth2</userinput>
714
812
</informalexample>
739
837
The only remaining weak point is that someone with physical
740
838
access to the client hard drive might turn off the client
741
computer, read the OpenPGP keys directly from the hard drive,
742
and communicate with the server. To safeguard against this, the
743
server is supposed to notice the client disappearing and stop
744
giving out the encrypted data. Therefore, it is important to
745
set the timeout and checker interval values tightly on the
746
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
747
845
>mandos</refentrytitle><manvolnum>8</manvolnum></citerefentry>.
750
848
It will also help if the checker program on the server is
751
849
configured to request something from the client which can not be
752
spoofed by someone else on the network, unlike unencrypted
753
<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.
756
855
<emphasis>Note</emphasis>: This makes it completely insecure to
805
<ulink url="http://www.gnu.org/software/gnutls/"
904
<ulink url="https://www.gnutls.org/">GnuTLS</ulink>
810
908
GnuTLS is the library this client uses to implement TLS for
811
909
communicating securely with the server, and at the same time
812
send the public OpenPGP key to the server.
910
send the public key to the server.
818
<ulink url="http://www.gnupg.org/related_software/gpgme/"
916
<ulink url="https://www.gnupg.org/related_software/gpgme/"
862
RFC 4346: <citetitle>The Transport Layer Security (TLS)
863
Protocol Version 1.1</citetitle>
960
RFC 5246: <citetitle>The Transport Layer Security (TLS)
961
Protocol Version 1.2</citetitle>
867
TLS 1.1 is the protocol implemented by GnuTLS.
965
TLS 1.2 is the protocol implemented by GnuTLS.
884
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
885
997
Security</citetitle>
889
This is implemented by GnuTLS and used by this program so
890
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