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 "2013-10-20">
5
<!ENTITY TIMESTAMP "2019-07-24">
6
6
<!ENTITY % common SYSTEM "../common.ent">
88
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>
92
114
<option>--priority <replaceable>STRING</replaceable></option>
143
169
brings up network interfaces, uses the interfaces’ IPv6
144
170
link-local addresses to get network connectivity, uses Zeroconf
145
171
to find servers on the local network, and communicates with
146
servers using TLS with an OpenPGP key to ensure authenticity and
147
confidentiality. This client program keeps running, trying all
148
servers on the network, until it receives a satisfactory reply
149
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
150
176
servers are periodically retried. If no servers are found it
151
177
will wait indefinitely for new servers to appear.
219
245
assumed to separate the address from the port number.
222
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
260
287
<replaceable>NAME</replaceable> can be the string
261
288
<quote><literal>none</literal></quote>; this will make
262
<command>&COMMANDNAME;</command> not bring up
263
<emphasis>any</emphasis> interfaces specified
264
<emphasis>after</emphasis> this string. This is not
265
recommended, and only meant for advanced users.
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
299
353
<term><option>--priority=<replaceable
300
354
>STRING</replaceable></option></term>
312
366
Sets the number of bits to use for the prime number in the
313
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
444
519
<refsect1 id="environment">
445
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
447
This program does not use any environment variables, not even
448
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
449
537
>cryptsetup</refentrytitle><manvolnum>8</manvolnum>
729
<term><filename>/conf/conf.d/mandos/tls-pubkey.pem</filename
731
<term><filename>/conf/conf.d/mandos/tls-privkey.pem</filename
735
Public and private raw key files, in <quote>PEM</quote>
736
format. These are the default file names, they can be
737
changed with the <option>--tls-pubkey</option> and
738
<option>--tls-privkey</option> options.
642
744
class="directory">/lib/mandos/network-hooks.d</filename></term>
686
787
</informalexample>
687
788
<informalexample>
689
Run in debug mode, and use a custom key:
790
Run in debug mode, and use custom keys:
693
794
<!-- do not wrap this line -->
694
<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>
697
798
</informalexample>
698
799
<informalexample>
700
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
701
802
to locate a server; connect directly to the IPv6 link-local
702
803
address <quote><systemitem class="ipaddress"
703
804
>fe80::aede:48ff:fe71:f6f2</systemitem></quote>, port 4711,
708
809
<!-- do not wrap this line -->
709
<userinput>&COMMANDNAME; --debug --pubkey keydir/pubkey.txt --seckey keydir/seckey.txt --connect fe80::aede:48ff:fe71:f6f2:4711 --interface eth2</userinput>
810
<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>
712
813
</informalexample>
715
816
<refsect1 id="security">
716
817
<title>SECURITY</title>
718
This program is set-uid to root, but will switch back to the
719
original (and presumably non-privileged) user and group after
720
bringing up the network interface.
819
This program assumes that it is set-uid to root, and will switch
820
back to the original (and presumably non-privileged) user and
821
group after bringing up the network interface.
723
824
To use this program for its intended purpose (see <xref
737
838
The only remaining weak point is that someone with physical
738
839
access to the client hard drive might turn off the client
739
computer, read the OpenPGP keys directly from the hard drive,
740
and communicate with the server. To safeguard against this, the
741
server is supposed to notice the client disappearing and stop
742
giving out the encrypted data. Therefore, it is important to
743
set the timeout and checker interval values tightly on the
744
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
745
846
>mandos</refentrytitle><manvolnum>8</manvolnum></citerefentry>.
748
849
It will also help if the checker program on the server is
749
850
configured to request something from the client which can not be
750
spoofed by someone else on the network, unlike unencrypted
751
<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.
754
856
<emphasis>Note</emphasis>: This makes it completely insecure to
803
<ulink url="http://www.gnu.org/software/gnutls/"
905
<ulink url="https://www.gnutls.org/">GnuTLS</ulink>
808
909
GnuTLS is the library this client uses to implement TLS for
809
910
communicating securely with the server, and at the same time
810
send the public OpenPGP key to the server.
911
send the public key to the server.
816
<ulink url="http://www.gnupg.org/related_software/gpgme/"
917
<ulink url="https://www.gnupg.org/related_software/gpgme/"
860
RFC 4346: <citetitle>The Transport Layer Security (TLS)
861
Protocol Version 1.1</citetitle>
961
RFC 5246: <citetitle>The Transport Layer Security (TLS)
962
Protocol Version 1.2</citetitle>
865
TLS 1.1 is the protocol implemented by GnuTLS.
966
TLS 1.2 is the protocol implemented by GnuTLS.
882
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
883
998
Security</citetitle>
887
This is implemented by GnuTLS and used by this program so
888
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
added
removed
plugins.d/mandos-client.xml
