NAME

       add_key - add a key to the kernel's key management facility

SYNOPSIS

       #include <keyutils.h>

       key_serial_t add_key(const char *type, const char *description,
                            const void *payload, size_t plen,
                            key_serial_t keyring);

DESCRIPTION

       add_key()  asks  the  kernel  to create or update a key of the given type and description, instantiate it
       with the payload of length plen, and to attach it to the nominated  keyring  and  to  return  its  serial
       number.

       The key type may reject the data if it's in the wrong format or in some other way invalid.

       If  the destination keyring already contains a key that matches the specified type and description, then,
       if the key type supports it, that key will be updated rather than a new key being created; if not, a  new
       key will be created and it will displace the link to the extant key from the keyring.

       The  destination  keyring  serial  number  may  be  that of a valid keyring to which the caller has write
       permission, or it may be a special keyring ID:

       KEY_SPEC_THREAD_KEYRING
              This specifies the caller's thread-specific keyring.

       KEY_SPEC_PROCESS_KEYRING
              This specifies the caller's process-specific keyring.

       KEY_SPEC_SESSION_KEYRING
              This specifies the caller's session-specific keyring.

       KEY_SPEC_USER_KEYRING
              This specifies the caller's UID-specific keyring.

       KEY_SPEC_USER_SESSION_KEYRING
              This specifies the caller's UID-session keyring.

KEY TYPES

       There are a number of key types available in the core key management code, and these can be specified  to
       this function:

       “user” Keys of the user-defined key type may contain a blob of arbitrary data, and the description may be
              any valid string, though  it  is  preferred  that  the  description  be  prefixed  with  a  string
              representing  the  service to which the key is of interest and a colon (for instance “afs:mykey”).
              The payload may be empty or NULL for keys of this type.

       “keyring”
              Keyrings are special key types that may contain links to sequences of other keys of any type.   If
              this  interface  is  used  to  create a keyring, then a NULL payload should be specified, and plen
              should be zero.

RETURN VALUE

       On success add_key() returns the serial number of the key it created or updated.  On error, the value  -1
       will be returned and errno will have been set to an appropriate error.

ERRORS

       ENOKEY The keyring doesn't exist.

       EKEYEXPIRED
              The keyring has expired.

       EKEYREVOKED
              The keyring has been revoked.

       EINVAL The payload data was invalid.

       ENOMEM Insufficient memory to create a key.

       EDQUOT The key quota for this user would be exceeded by creating this key or linking it to the keyring.

       EACCES The keyring wasn't available for modification by the user.

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), keyctl(2), request_key(2), keyctl(3), keyrings(7)

COLOPHON

       This page is part of release 4.04 of  the  Linux  man-pages  project.   A  description  of  the  project,
       information   about   reporting   bugs,   and   the  latest  version  of  this  page,  can  be  found  at
       http://www.kernel.org/doc/man-pages/.