linux man page for keyctl_update

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 char *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	      The key specified had been revoked.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_get_keyring_ID(3),
       keyctl_join_session_keyring(3),
       keyctl_revoke(3),
       keyctl_chown(3),
       keyctl_setperm(3),
       keyctl_describe(3),
       keyctl_clear(3),
       keyctl_link(3),
       keyctl_unlink(3),
       keyctl_search(3),
       keyctl_read(3),
       keyctl_instantiate(3),
       keyctl_negate(3),
       keyctl_set_reqkey_keyring(3),
       keyctl_set_timeout(3),
       keyctl_assume_authority(3),
       keyctl_describe_alloc(3),
       keyctl_read_alloc(3),
       request-key(8)

Linux								    4 May 2006							  KEYCTL_UPDATE(3)