NAME

       user-keyring - Per-user keyring

DESCRIPTION

       The  user  keyring  is a keyring used to anchor keys on behalf of a user.  Each UID the kernel deals with
       has its own user keyring.  This keyring is associated with the record that the kernel maintains  for  the
       UID  and,  once created, is retained as long as that record persists.  It is shared amongst all processes
       of that UID.

       The user keyring is created on demand when a thread requests it.  Normally, this happens when pam_keyinit
       is invoked when a user logs in.

       The user keyring is not searched by default by request_key().  When  the  pam_keyinit  module  creates  a
       session  keyring, it adds to it a link to the user keyring so that the user keyring will be searched when
       the session keyring is.

       A special serial number value, KEY_SPEC_USER_KEYRING, is defined that can be used in lieu of the  calling
       process's user keyring's actual serial number.

       From the keyctl utility, '@u' can be used instead of a numeric key ID in much the same way.

       User keyrings are independent of clone(), fork(), vfork(), execve() and exit() excepting that the keyring
       is destroyed when the UID record is destroyed when the last process pinning it exits.

       If  it  necessary  to  for  a  key  associated  with  a user to exist beyond the UID record being garbage
       collected - for example for use by a cron script - then the persistent keyring should be used instead.

       If a user keyring does not exist when it is accessed, it will be created.

SEE ALSO

       keyctl(1),
       keyctl(3),
       keyrings(7),
       pam_keyinit(8),
       process-keyring(7),
       session-keyring(7),
       thread-keyring(7),
       user-session-keyring(7),
       persistent-keyring(7)

Linux                                              20 Feb 2014                                   USER-KEYRING(7)