man/request-key.conf.5

.\" -*- nroff -*-
.\" Copyright (C) 2005 Red Hat, Inc. All Rights Reserved.
.\" Written by David Howells (dhowells@redhat.com)
.\"
.\" This program is free software; you can redistribute it and/or
.\" modify it under the terms of the GNU General Public License
.\" as published by the Free Software Foundation; either version
.\" 2 of the License, or (at your option) any later version.
.\"
.TH REQUEST-KEY.CONF 5 "15 November 2011" Linux "Linux Key Management Utilities"
.SH NAME
request\-key.conf \- Instantiation handler configuration file
.SH DESCRIPTION
.P
These files are used by the /sbin/request\-key program to determine which
program it should run to instantiate a key.
.P
request\-key looks for the best match, reading all the following files:
.IP
	/etc/request\-key.d/*.conf
.br
	/etc/request\-key.conf
.P
If it doesn't find a match, it will return an error
and the kernel will automatically negate the key.
.P
The best match is defined as the line with the shortest wildcard skips, ranking
the columns in order left to right.  If two lines have the same length skips,
then the first read is the one taken.
.P
In the files, any blank line or line beginning with a hash mark '#' is
considered to be a comment and ignored.
.P
All other lines are assumed to be command lines with a number of white space
separated fields:
.P
<op> <type> <description> <callout\-info> <prog> <arg1> <arg2> ...
.P
The first four fields are used to match the parameters passed to request\-key by
the kernel. \fIop\fR is the operation type; currently the only supported
operation is "create".
.P
\fItype\fR, \fIdescription\fR and \fIcallout\-info\fR match the three
parameters passed to \fBkeyctl request2\fR or the \fBrequest_key()\fR system
call.  Each of these may contain one asterisk '*' character as a wildcard
anywhere within the string.
.P
Should a match be made, the program specified by <prog> will be exec'd. This
must have a fully qualified path name. argv[0] will be set from the part of the
program name that follows the last slash '/' character.
.P
If the program name is prefixed with a pipe bar character '|', then the program
will be forked and exec'd attached to three pipes. The callout information will
be piped to it on it's stdin and the intended payload data will be retrieved
from its stdout. Anything sent to stderr will be posted in syslog. If the
program exits 0, then /sbin/request\-key will attempt to instantiate the key
with the data read from stdout. If it fails in any other way, then request\-key
will attempt to execute the appropriate 'negate' operation command.
.P
The program arguments can be substituted with various macros. Only complete
argument substitution is supported - macro substitutions can't be embedded. All
macros begin with a percent character '%'. An argument beginning with two
percent characters will have one of them discarded.
.P
The following macros are supported:
.P
.RS
%o    Operation type
.br
%k    Key ID
.br
%t    Key type
.br
%d    Key description
.br
%c    Callout information
.br
%u    Key UID
.br
%g    Key GID
.br
%T    Requestor's thread keyring
.br
%P    Requestor's process keyring
.br
%S    Requestor's session keyring
.RE
.P
There's another macro substitution too that permits the interpolation of the
contents of a key:
.P
.RS
%{<type>:<description>}
.RE
.P
This performs a lookup for a key of the given type and description on the
requestor's keyrings, and if found, substitutes the contents for the macro. If
not found an error will be logged and the key under construction will be
negated.
.SH EXAMPLE
.P
A basic file will be installed in the /etc. This will contain two debugging
lines that can be used to test the installation:
.P
.RS
create user debug:* negate /bin/keyctl negate %k 30 %S
.br
create user debug:loop:* * |/bin/cat
.br
create user debug:* * /usr/share/keyutils/request\-key\-debug.sh %k %d %c %S
.br
negate * * * /bin/keyctl negate %k 30 %S
.RE
.P
This is set up so that something like:
.P
.RS
keyctl request2 user debug:xxxx negate
.RE
.P
will create a negative user-defined key, something like:
.P
.RS
keyctl request2 user debug:yyyy spoon
.RE
.P
will create an instantiated user-defined key with "Debug spoon" as the payload,
and something like:
.P
.RS
keyctl request2 user debug:loop:zzzz abcdefghijkl
.RE
.P
will create an instantiated user-defined key with the callout information as
the payload.
.SH FILES
.ul
/etc/request\-key.conf
.ul 0
.br
.ul
/etc/request\-key.d/*.conf
.ul 0
.SH SEE ALSO
\fBkeyctl\fR(1), \fBrequest\-key.conf\fR(5)