KEYCTL_RESTRICT_KEYRING(2const) - Linux manual page (original) (raw)

KEYCTLRESTRICTKEYRING(2const) KEYCTLRESTRICTKEYRING(2const)

NAME top

   KEYCTL_RESTRICT_KEYRING - restrict keys that may be linked to a
   keyring

LIBRARY top

   Standard C library (_libc_, _-lc_)

SYNOPSIS top

   **#include <linux/keyctl.h>** /* Definition of **KEY*** constants */
   **#include <sys/syscall.h>** /* Definition of **SYS_*** constants */
   **#include <unistd.h>**

   **long syscall(SYS_keyctl, KEYCTL_RESTRICT_KEYRING, key_serial_t** _keyring_**,**
                **const char *_Nullable** _type_**, const char ***_restriction_**);**

DESCRIPTION top

   Apply a key-linking restriction to the keyring with the ID
   provided in _keyring_.  The caller must have _setattr_ permission on
   the key.  If _type_ is NULL, any attempt to add a key to the keyring
   is blocked; otherwise it contains a pointer to a string with a key
   type name and _restriction_ contains a pointer to string that
   describes the type-specific restriction.  As of Linux 4.12, only
   the type "asymmetric" has restrictions defined:

   **builtin_trusted**
          Allows only keys that are signed by a key linked to the
          built-in keyring (".builtin_trusted_keys").

   **builtin_and_secondary_trusted**
          Allows only keys that are signed by a key linked to the
          secondary keyring (".secondary_trusted_keys") or, by
          extension, a key in a built-in keyring, as the latter is
          linked to the former.

   **key_or_keyring:**_key_
   **key_or_keyring:**_key_**:chain**
          If _key_ specifies the ID of a key of type "asymmetric", then
          only keys that are signed by this key are allowed.

          If _key_ specifies the ID of a keyring, then only keys that
          are signed by a key linked to this keyring are allowed.

          If ":chain" is specified, keys that are signed by a keys
          linked to the destination keyring (that is, the keyring
          with the ID specified in the _keyring_ argument) are also
          allowed.

   Note that a restriction can be configured only once for the
   specified keyring; once a restriction is set, it can't be
   overridden.

RETURN VALUE top

   On success, 0 is returned.

   On error, -1 is returned, and _[errno](../man3/errno.3.html)_ is set to indicate the error.

ERRORS top

   **EDEADLK**
          The requested keyring restriction would result in a cycle.

   **EEXIST** _keyring_ already has a restriction set.

   **ENOENT** The type provided in _type_ argument doesn't support setting
          key linking restrictions.

   **EOPNOTSUPP**
          _type_ was "asymmetric", and the key specified in the
          restriction specification provided in _restriction_ has type
          other than "asymmetric" or "keyring".

VERSIONS top

   A wrapper is provided in the _libkeyutils_ library:
   [keyctl_restrict_keyring(3)](../man3/keyctl%5Frestrict%5Fkeyring.3.html).

STANDARDS top

   Linux.

HISTORY top

   Linux 4.12.

SEE ALSO top

   [keyctl(2)](../man2/keyctl.2.html), [keyctl_restrict_keyring(3)](../man3/keyctl%5Frestrict%5Fkeyring.3.html)

COLOPHON top

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Linux man-pages 6.10 2024-08-21_KEYCTLRESTRICTKEYRING_(2const)

Pages that refer to this page:keyctl(2)