xenial (7) user-session-keyring.7.gz

NAME

       user-session-keyring - Per-user default session keyring

DESCRIPTION

       The user session keyring is a keyring used to anchor keys on behalf of a user.  Each UID the kernel deals
       with has its own user session 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 session keyring is created on demand when a thread requests it or when a  thread  asks  for  its
       session  keyring and that doesn't exist.  In the latter case, a user session keyring will be created and,
       if the session keyring wasn't to be created, the user session keyring will be set as the process's actual
       session keyring.

       The user session keyring is searched by request_key() if the actual session keyring does not exist and is
       ignored otherwise.

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

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

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

       It is strongly recommended that a session keyring be set explicitly, for example by  pam_keyinit,  rather
       than relying on the user session keyring - particularly if a process is running as root.

SEE ALSO

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