REQUEST-KEY.CONF(5) Linux Key Management Utilities REQUEST-KEY.CONF(5)
request-key.conf - Instantiation handler configuration file
This file and its associated key-type specific variants are used by the
/sbin/request-key program to determine which program it should run to
instantiate a key.
request-key looks first in /etc/request-key.d/ for a file of the key
type name plus ".conf" that it can use. If that is not found, it will
fall back to /etc/request-key.conf.
request-key scans through the chosen file one line at a time until it
finds a match, which it will then use. If it doesn't find a match,
it'll return an error and the kernel will automatically negate the key.
Any blank line or line beginning with a hash mark '#' is considered to
be a comment and ignored.
All other lines are assumed to be command lines with a number of white
space separated fields:
<op> <type> <description> <callout-info> <prog> <arg1> <arg2> ...
The first four fields are used to match the parameters passed to
request-key by the kernel. op is the operation type; currently the only
supported operation is "create".
type, description and callout-info match the three parameters passed to
keyctl request2 or the request_key() system call. Each of these may
contain one or more asterisk '*' characters as wildcards anywhere
within the string.
Should a match be made, the program specified by <prog> will be exec'd.
This must have a fully qualified path name. argv will be set from
the part of the program name that follows the last slash '/' character.
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.
The program arguments can be substituted with various macros. Only com‐
plete 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.
The following macros are supported:
%o Operation type
%k Key ID
%t Key type
%d Key description
%c Callout information
%u Key UID
%g Key GID
%T Requestor's thread keyring
%P Requestor's process keyring
%S Requestor's session keyring
There's another macro substitution too that permits the interpolation
of the contents of a key:
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 con‐
struction will be negated.
A basic file will be installed in the /etc. This will contain two
debugging lines that can be used to test the installation:
create user debug:* negate /bin/keyctl negate %k 30 %S
create user debug:loop:* * |/bin/cat
create user debug:* * /usr/share/keyutils/request-key-debug.sh
%k %d %c %S
negate * * * /bin/keyctl negate %k 30 %S
This is set up so that something like:
keyctl request2 user debug:xxxx negate
will create a negative user-defined key, something like:
keyctl request2 user debug:yyyy spoon
will create an instantiated user-defined key with "Debug spoon" as the
payload, and something like:
keyctl request2 user debug:loop:zzzz abcdefghijkl
will create an instantiated user-defined key with the callout informa‐
tion as the payload.
Linux 15 November 2011 REQUEST-KEY.CONF(5)