NAME

       session-keyring - session shared process keyring

DESCRIPTION

       The  session  keyring  is  a  keyring  used  to anchor keys on behalf of a process.  It is
       typically created by pam_keyinit(8) when a user logs in and a  link  will  be  added  that
       refers  to the user-keyring(7).  Optionally, PAM may revoke the session keyring on logout.
       (In typical configurations, PAM does do this revocation.)  The  session  keyring  has  the
       name (description) _ses.

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

       From the keyctl(1) utility, '@s' can be used instead of a numeric key ID in much the  same
       way.

       A  process's  session  keyring  is  inherited across clone(2), fork(2), and vfork(2).  The
       session keyring is preserved across execve(2), even when the executable is set-user-ID  or
       set-group-ID  or has capabilities.  The session keyring is destroyed when the last process
       that refers to it exits.

       If a process doesn't have a session keyring when  it  is  accessed,  then,  under  certain
       circumstances,  the  user-session-keyring(7)  will  be attached as the session keyring and
       under others a new session keyring will  be  created.   (See  user-session-keyring(7)  for
       further details.)

   Special operations
       The  keyutils  library  provides the following special operations for manipulating session
       keyrings:

       keyctl_join_session_keyring(3)
              This operation allows the caller to change the session keyring that  it  subscribes
              to.   The  caller can join an existing keyring with a specified name (description),
              create a new keyring with a  given  name,  or  ask  the  kernel  to  create  a  new
              "anonymous"  session  keyring with the name "_ses".  (This function is an interface
              to the keyctl(2) KEYCTL_JOIN_SESSION_KEYRING operation.)

       keyctl_session_to_parent(3)
              This operation allows the caller to make the parent process's  session  keyring  to
              the  same  as its own.  For this to succeed, the parent process must have identical
              security attributes and must be single threaded.  (This function is an interface to
              the keyctl(2) KEYCTL_SESSION_TO_PARENT operation.)

       These operations are also exposed through the keyctl(1) utility as:

           keyctl session
           keyctl session - [<prog> <arg1> <arg2> ...]
           keyctl session <name> [<prog> <arg1> <arg2> ...]

       and:

           keyctl new_session

SEE ALSO

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

COLOPHON

       This page is part of release 5.10 of the Linux man-pages project.  A description of the
       project, information about reporting bugs, and the latest version of this page, can be
       found at https://www.kernel.org/doc/man-pages/.