keyctl_search(3) — Linux manual page


KEYCTL_SEARCH(3)       Linux Key Management Calls       KEYCTL_SEARCH(3)

NAME         top

       keyctl_search - search a keyring for a key

SYNOPSIS         top

       #include <keyutils.h>

       long keyctl_search(key_serial_t keyring, const char *type,
       const char *description, key_serial_t destination);

DESCRIPTION         top

       keyctl_search() recursively searches the keyring for a key of the
       specified type and description.

       If found, the key will be attached to the destination keyring (if
       given), and its serial number will be returned.

       The source keyring must grant search permission to the caller,
       and for a key to be found, it must also grant search permission
       to the caller.  Child keyrings will be only be recursively
       searched if they grant search permission to the caller as well.

       If the destination keyring is zero, no attempt will be made to
       forge a link to the key, and just the serial number will be

       If the destination keyring is given, then the link may only be
       formed if the found key grants the caller link permission and the
       destination keyring grants the caller write permission.

       If the search is successful, and if the destination keyring
       already contains a link to a key that matches the specified type
       and description, then that link will be replaced by a link to the
       found key.

       The source keyring and destination keyring serial numbers may be
       those of valid keyrings to which the caller has appropriate
       permission, or they may be special keyring IDs:

              This specifies the caller's thread-specific keyring.

              This specifies the caller's process-specific keyring.

              This specifies the caller's session-specific keyring.

              This specifies the caller's UID-specific keyring.

              This specifies the caller's UID-session keyring.

RETURN VALUE         top

       On success keyctl_search() returns the serial number of the key
       it found.  On error, the value -1 will be returned and errno will
       have been set to an appropriate error.

ERRORS         top

       ENOKEY One of the keyrings doesn't exist, no key was found by the
              search, or the only key found by the search was a negative

              One of the keyrings is a valid key that isn't a keyring.

              One of the keyrings has expired, or the only key found was

              One of the keyrings has been revoked, or the only key
              found was revoked.

       ENOMEM Insufficient memory to expand the destination keyring.

       EDQUOT The key quota for this user would be exceeded by creating
              a link to the found key in the destination keyring.

       EACCES The source keyring didn't grant search permission, the
              destination keyring didn't grant write permission or the
              found key didn't grant link permission to the caller.

LINKING         top

       Although this is a Linux system call, it is not present in libc
       but can be found rather in libkeyutils.  When linking, -lkeyutils
       should be specified to the linker.

SEE ALSO         top

       keyctl(1), add_key(2), keyctl(2), request_key(2), keyctl(3),
       keyrings(7), keyutils(7)

COLOPHON         top

       This page is part of the keyutils (key management utilities)
       project.  Information about the project can be found at [unknown
       -- if you know, please contact] If you have a
       bug report for this manual page, send it to  This page was obtained from the
       project's upstream Git repository
       on 2023-12-22.  (At that time, the date of the most recent commit
       that was found in the repository was 2023-03-20.)  If you
       discover any rendering problems in this HTML version of the page,
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       information in this COLOPHON (which is not part of the original
       manual page), send a mail to

Linux                          4 May 2006               KEYCTL_SEARCH(3)

Pages that refer to this page: keyctl(2)keyctl(3)keyrings(7)