KEYCTL(2)

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:

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 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

EACCES
    A key operation wasn't permitted.

EDQUOT
    The key quota for the caller's user would be exceeded by creating a key or linking it to the keyring.

EKEYEXPIRED
    An expired key was found or specified.

EKEYREJECTED
    A rejected key was found or specified.

EKEYREVOKED
    A revoked key was found or specified.

ENOKEY
    No matching key was found or an invalid key was specified.

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.

SEE ALSO
keyctl(1), add_key(2), request_key(2), keyctl_set_timeout(3), keyctl_chown(3), keyctl_clear(3), keyctl_describe(3), keyctl_describe_alloc(3), keyctl_get_keyring_ID(3), keyctl_instantiate(3), keyctl_join_session_keyring(3), keyctl_link(3), keyctl_negate(3), keyctl_revoke(3), keyctl_search(3), keyctl_setperm(3), keyctl_set_reqkey_keyring(3), keyctl_set_timeout(3), keyctl_read(3), keyctl_read_alloc(3), keyctl_unlink(3), keyctl_update(3), keyrings(7), request-key(8)

The kernel source file Documentation/security/keys.txt.

COLOPHON
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