ADD_KEY(2)                                         Linux Key Management Calls                                         ADD_KEY(2)



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)



Linux                                                      4 May 2006                                                 ADD_KEY(2)