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KEYCTL_UPDATE(3)          Linux Key Management Calls          KEYCTL_UPDATE(3)
NAME
       keyctl_update - update a key
SYNOPSIS
       #include <keyutils.h>
       long keyctl_update(key_serial_t key, const void *payload,
       size_t plen);
DESCRIPTION
       keyctl_update()  updates  the  payload of a key if the key type permits
       it.
       The caller must have write permission on a key to be able update it.
       payload and plen specify the data for the new payload.  payload may  be
       NULL  and  plen may be zero if the key type permits that.  The key type
       may reject the data if it's in the wrong format or in  some  other  way
       invalid.
RETURN VALUE
       On  success  keyctl_update() returns 0.  On error, the value -1 will be
       returned and errno will have been set to an appropriate error.
ERRORS
       ENOKEY The key specified is invalid.
       EKEYEXPIRED
              The key specified has expired.
       EKEYREVOKED
              The key specified had been revoked.
       EINVAL The payload data was invalid.
       ENOMEM Insufficient memory to store the new payload.
       EDQUOT The key quota for this user would be exceeded by increasing  the
              size of the key to accommodate the new payload.
       EACCES The key exists, but is not writable by the calling process.
       EOPNOTSUPP
              The key type does not support the update operation on its keys.
LINKING
       This  is  a  library  function  that can be found in libkeyutils.  When
       linking, -lkeyutils should be specified to the linker.
SEE ALSO
       keyctl(1), add_key(2), keyctl(2), request_key(2), keyctl(3),
       keyrings(7), keyutils(7)
Linux                             4 May 2006                  KEYCTL_UPDATE(3)