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       request-key.conf - Instantiation handler configuration file


       This  file  is used by the /sbin/request-key program to determine which
       program it should run to instantiate a key.

       request-key works scans through the file a 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[0] 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
       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.

       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
       construction 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/
              %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
       information as the payload.




       keyctl(1), request-key.conf(5)