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 "2013-06-21">
5
<!ENTITY TIMESTAMP "2019-02-09">
6
6
<!ENTITY % common SYSTEM "../common.ent">
87
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>
91
113
<option>--priority <replaceable>STRING</replaceable></option>
142
168
brings up network interfaces, uses the interfaces’ IPv6
143
169
link-local addresses to get network connectivity, uses Zeroconf
144
170
to find servers on the local network, and communicates with
145
servers using TLS with an OpenPGP key to ensure authenticity and
146
confidentiality. This client program keeps running, trying all
147
servers on the network, until it receives a satisfactory reply
148
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
149
175
servers are periodically retried. If no servers are found it
150
176
will wait indefinitely for new servers to appear.
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
259
286
<replaceable>NAME</replaceable> can be the string
260
287
<quote><literal>none</literal></quote>; this will make
261
<command>&COMMANDNAME;</command> not bring up
262
<emphasis>any</emphasis> interfaces specified
263
<emphasis>after</emphasis> this string. This is not
264
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
298
352
<term><option>--priority=<replaceable
299
353
>STRING</replaceable></option></term>
311
365
Sets the number of bits to use for the prime number in the
312
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
443
518
<refsect1 id="environment">
444
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.
446
This program does not use any environment variables, not even
447
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
448
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.
641
743
class="directory">/lib/mandos/network-hooks.d</filename></term>
685
786
</informalexample>
686
787
<informalexample>
688
Run in debug mode, and use a custom key:
789
Run in debug mode, and use custom keys:
692
793
<!-- do not wrap this line -->
693
<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>
696
797
</informalexample>
697
798
<informalexample>
699
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
700
801
to locate a server; connect directly to the IPv6 link-local
701
802
address <quote><systemitem class="ipaddress"
702
803
>fe80::aede:48ff:fe71:f6f2</systemitem></quote>, port 4711,
707
808
<!-- do not wrap this line -->
708
<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>
711
812
</informalexample>
736
837
The only remaining weak point is that someone with physical
737
838
access to the client hard drive might turn off the client
738
computer, read the OpenPGP keys directly from the hard drive,
739
and communicate with the server. To safeguard against this, the
740
server is supposed to notice the client disappearing and stop
741
giving out the encrypted data. Therefore, it is important to
742
set the timeout and checker interval values tightly on the
743
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
744
845
>mandos</refentrytitle><manvolnum>8</manvolnum></citerefentry>.
747
848
It will also help if the checker program on the server is
748
849
configured to request something from the client which can not be
749
spoofed by someone else on the network, unlike unencrypted
750
<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.
753
855
<emphasis>Note</emphasis>: This makes it completely insecure to
802
<ulink url="http://www.gnu.org/software/gnutls/"
904
<ulink url="https://www.gnutls.org/">GnuTLS</ulink>
807
908
GnuTLS is the library this client uses to implement TLS for
808
909
communicating securely with the server, and at the same time
809
send the public OpenPGP key to the server.
910
send the public key to the server.
815
<ulink url="http://www.gnupg.org/related_software/gpgme/"
916
<ulink url="https://www.gnupg.org/related_software/gpgme/"
859
RFC 4346: <citetitle>The Transport Layer Security (TLS)
860
Protocol Version 1.1</citetitle>
960
RFC 5246: <citetitle>The Transport Layer Security (TLS)
961
Protocol Version 1.2</citetitle>
864
TLS 1.1 is the protocol implemented by GnuTLS.
965
TLS 1.2 is the protocol implemented by GnuTLS.
881
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
882
997
Security</citetitle>
886
This is implemented by GnuTLS and used by this program so
887
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