1
<?xml version="1.0" encoding="UTF-8"?>
2
<!DOCTYPE refentry PUBLIC "-//OASIS//DTD DocBook XML V4.5//EN"
3
"http://www.oasis-open.org/docbook/xml/4.5/docbookx.dtd" [
4
<!ENTITY COMMANDNAME "splashy">
5
<!ENTITY TIMESTAMP "2019-02-10">
6
<!ENTITY % common SYSTEM "../common.ent">
10
<refentry xmlns:xi="http://www.w3.org/2001/XInclude">
12
<title>Mandos Manual</title>
13
<!-- NWalsh’s docbook scripts use this to generate the footer: -->
14
<productname>Mandos</productname>
15
<productnumber>&version;</productnumber>
16
<date>&TIMESTAMP;</date>
19
<firstname>Björn</firstname>
20
<surname>Påhlsson</surname>
22
<email>belorn@recompile.se</email>
26
<firstname>Teddy</firstname>
27
<surname>Hogeborn</surname>
29
<email>teddy@recompile.se</email>
46
<holder>Teddy Hogeborn</holder>
47
<holder>Björn Påhlsson</holder>
49
<xi:include href="../legalnotice.xml"/>
53
<refentrytitle>&COMMANDNAME;</refentrytitle>
54
<manvolnum>8mandos</manvolnum>
58
<refname><command>&COMMANDNAME;</command></refname>
59
<refpurpose>Mandos plugin to use splashy to get a
60
password.</refpurpose>
65
<command>&COMMANDNAME;</command>
69
<refsect1 id="description">
70
<title>DESCRIPTION</title>
72
This program prompts for a password using <citerefentry>
73
<refentrytitle>splashy_update</refentrytitle>
74
<manvolnum>8</manvolnum></citerefentry> and outputs any given
75
password to standard output. If no <citerefentry><refentrytitle
76
>splashy</refentrytitle><manvolnum>8</manvolnum></citerefentry>
77
process can be found, this program will immediately exit with an
78
exit code indicating failure.
81
This program is not very useful on its own. This program is
82
really meant to run as a plugin in the <application
83
>Mandos</application> client-side system, where it is used as a
84
fallback and alternative to retrieving passwords from a
85
<application >Mandos</application> server.
88
If this program is killed (presumably by
89
<citerefentry><refentrytitle>plugin-runner</refentrytitle>
90
<manvolnum>8mandos</manvolnum></citerefentry> because some other
91
plugin provided the password), it cannot tell <citerefentry>
92
<refentrytitle>splashy</refentrytitle><manvolnum>8</manvolnum>
93
</citerefentry> to abort requesting a password, because
94
<citerefentry><refentrytitle>splashy</refentrytitle>
95
<manvolnum>8</manvolnum></citerefentry> does not support this.
96
Therefore, this program will then <emphasis>kill</emphasis> the
97
running <citerefentry><refentrytitle>splashy</refentrytitle>
98
<manvolnum>8</manvolnum></citerefentry> process and start a
99
<emphasis>new</emphasis> one, using <quote><literal
100
>boot</literal></quote> as the only argument.
104
<refsect1 id="options">
105
<title>OPTIONS</title>
107
This program takes no options.
111
<refsect1 id="exit_status">
112
<title>EXIT STATUS</title>
114
If exit status is 0, the output from the program is the password
115
as it was read. Otherwise, if exit status is other than 0, the
116
program was interrupted or encountered an error, and any output
117
so far could be corrupt and/or truncated, and should therefore
122
<refsect1 id="environment">
123
<title>ENVIRONMENT</title>
126
<term><envar>cryptsource</envar></term>
127
<term><envar>crypttarget</envar></term>
130
If set, these environment variables will be assumed to
131
contain the source device name and the target device
132
mapper name, respectively, and will be shown as part of
136
These variables will normally be inherited from
137
<citerefentry><refentrytitle>plugin-runner</refentrytitle>
138
<manvolnum>8mandos</manvolnum></citerefentry>, which will
139
normally have inherited them from
140
<filename>/scripts/local-top/cryptroot</filename> in the
141
initial <acronym>RAM</acronym> disk environment, which will
142
have set them from parsing kernel arguments and
143
<filename>/conf/conf.d/cryptroot</filename> (also in the
144
initial RAM disk environment), which in turn will have been
145
created when the initial RAM disk image was created by
147
>/usr/share/initramfs-tools/hooks/cryptroot</filename>, by
148
extracting the information of the root file system from
149
<filename >/etc/crypttab</filename>.
152
This behavior is meant to exactly mirror the behavior of
153
<command>askpass</command>, the default password prompter.
160
<refsect1 id="files">
164
<term><filename>/sbin/splashy_update</filename></term>
167
This is the command run to retrieve a password from
168
<citerefentry><refentrytitle>splashy</refentrytitle>
169
<manvolnum>8</manvolnum></citerefentry>. See
170
<citerefentry><refentrytitle
171
>splashy_update</refentrytitle><manvolnum>8</manvolnum>
177
<term><filename>/proc</filename></term>
180
To find the running <citerefentry><refentrytitle
181
>splashy</refentrytitle><manvolnum>8</manvolnum>
182
</citerefentry>, this directory will be searched for
183
numeric entries which will be assumed to be directories.
184
In all those directories, the <filename>exe</filename>
185
entry will be used to determine the name of the running
186
binary and the effective user and group
187
<abbrev>ID</abbrev> of the process. See <citerefentry>
188
<refentrytitle>proc</refentrytitle><manvolnum
189
>5</manvolnum></citerefentry>.
194
<term><filename>/sbin/splashy</filename></term>
197
This is the name of the binary which will be searched for
198
in the process list. See <citerefentry><refentrytitle
199
>splashy</refentrytitle><manvolnum>8</manvolnum>
210
Killing <citerefentry><refentrytitle>splashy</refentrytitle>
211
<manvolnum>8</manvolnum></citerefentry> and starting a new one
212
is ugly, but necessary as long as it does not support aborting a
215
<xi:include href="../bugs.xml"/>
218
<refsect1 id="example">
219
<title>EXAMPLE</title>
221
Note that normally, this program will not be invoked directly,
222
but instead started by the Mandos <citerefentry><refentrytitle
223
>plugin-runner</refentrytitle><manvolnum>8mandos</manvolnum>
228
This program takes no options.
231
<userinput>&COMMANDNAME;</userinput>
236
<refsect1 id="security">
237
<title>SECURITY</title>
239
If this program is killed by a signal, it will kill the process
240
<abbrev>ID</abbrev> which at the start of this program was
241
determined to run <citerefentry><refentrytitle
242
>splashy</refentrytitle><manvolnum>8</manvolnum></citerefentry>
243
as root (see also <xref linkend="files"/>). There is a very
244
slight risk that, in the time between those events, that process
245
<abbrev>ID</abbrev> was freed and then taken up by another
246
process; the wrong process would then be killed. Now, this
247
program can only be killed by the user who started it; see
248
<citerefentry><refentrytitle>plugin-runner</refentrytitle>
249
<manvolnum>8mandos</manvolnum></citerefentry>. This program
250
should therefore be started by a completely separate
251
non-privileged user, and no other programs should be allowed to
252
run as that special user. This means that it is not recommended
253
to use the user "nobody" to start this program, as other
254
possibly less trusted programs could be running as "nobody", and
255
they would then be able to kill this program, triggering the
256
killing of the process <abbrev>ID</abbrev> which may or may not
257
be <citerefentry><refentrytitle>splashy</refentrytitle>
258
<manvolnum>8</manvolnum></citerefentry>.
261
The only other thing that could be considered worthy of note is
262
this: This program is meant to be run by <citerefentry>
263
<refentrytitle>plugin-runner</refentrytitle><manvolnum
264
>8mandos</manvolnum></citerefentry>, and will, when run
265
standalone, outside, in a normal environment, immediately output
266
on its standard output any presumably secret password it just
267
received. Therefore, when running this program standalone
268
(which should never normally be done), take care not to type in
269
any real secret password by force of habit, since it would then
270
immediately be shown as output.
274
<refsect1 id="see_also">
275
<title>SEE ALSO</title>
277
<citerefentry><refentrytitle>intro</refentrytitle>
278
<manvolnum>8mandos</manvolnum></citerefentry>,
279
<citerefentry><refentrytitle>crypttab</refentrytitle>
280
<manvolnum>5</manvolnum></citerefentry>,
281
<citerefentry><refentrytitle>plugin-runner</refentrytitle>
282
<manvolnum>8mandos</manvolnum></citerefentry>,
283
<citerefentry><refentrytitle>proc</refentrytitle>
284
<manvolnum>5</manvolnum></citerefentry>,
285
<citerefentry><refentrytitle>splashy</refentrytitle>
286
<manvolnum>8</manvolnum></citerefentry>,
287
<citerefentry><refentrytitle>splashy_update</refentrytitle>
288
<manvolnum>8</manvolnum></citerefentry>
292
<!-- Local Variables: -->
293
<!-- time-stamp-start: "<!ENTITY TIMESTAMP [\"']" -->
294
<!-- time-stamp-end: "[\"']>" -->
295
<!-- time-stamp-format: "%:y-%02m-%02d" -->