keyctl() - Unix, Linux System Call

NAME

keyctl - Manipulate the kernel’s key management facility

SYNOPSIS

#include <keyutils.h> 

long keyctl(int cmd, ...);

DESCRIPTION

keyctl() has a number of functions available:

Tag	Description
KEYCTL_GET_KEYRING_ID
	Ask for a keyring’s ID.
KEYCTL_JOIN_SESSION_KEYRING
	Join or start named session keyring.
KEYCTL_UPDATE
	Update a key.
KEYCTL_REVOKE
	Revoke a key.
KEYCTL_CHOWN
	Set ownership of a key.
KEYCTL_SETPERM
	Set perms on a key.
KEYCTL_DESCRIBE
	Describe a key.
KEYCTL_CLEAR
	Clear contents of a keyring.
KEYCTL_LINK
	Link a key into a keyring.
KEYCTL_UNLINK
	Unlink a key from a keyring.
KEYCTL_SEARCH
	Search for a key in a keyring.
KEYCTL_READ
	Read a key or keyring’s contents.
KEYCTL_INSTANTIATE
	Instantiate a partially constructed key.
KEYCTL_NEGATE
	Negate a partially constructed key.
KEYCTL_SET_REQKEY_KEYRING
	Set default request-key keyring.
KEYCTL_SET_TIMEOUT
	Set timeout on a key.
KEYCTL_ASSUME_AUTHORITY
	Assume authority to instantiate key.

These are wrapped by libkeyutils into individual functions to permit compiler the compiler to check types. See the See Also section at the bottom.

RETURN VALUE

On success keyctl() 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

Tag	Description
ENOKEY	No matching key was found or an invalid key was specified.
EKEYEXPIRED
	An expired key was found or specified.
EKEYREVOKED
	A revoked key was found or specified.
EKEYREJECTED
	A rejected key was found or specified.
EDQUOT	The key quota for the caller’s user would be exceeded by creating a key or linking it to the keyring.
EACCES	A key operation wasn’t permitted.

LINKING

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.

add_key(2),
request_key(2),
keyctl_get_keyring_ID(3),
keyctl_join_session_keyring(3),
keyctl_update(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)