Provided by: libkeyutils-dev_1.5.2-2_amd64 bug

NAME

       keyctl_assume_authority - Assume the authority to instantiate a key
       keyctl_instantiate - Instantiate a key from flat data
       keyctl_instantiate_iov - Instantiate a key from segmented data
       keyctl_reject - Negatively instantiate a key specifying search error
       keyctl_negate - Negatively instantiate a key

SYNOPSIS

       #include <keyutils.h>

       long keyctl_assume_authority(key_serial_t key);

       long keyctl_instantiate(key_serial_t key, const void *payload,
       size_t plen, key_serial_t keyring);

       long keyctl_instantiate_iov(key_serial_t key,
       const struct iovec *payload_iov, unsigned ioc,
       key_serial_t keyring);

       long keyctl_negate(key_serial_t key, unsigned timeout,
       key_serial_t keyring);

       long keyctl_reject(key_serial_t key, unsigned timeout,
       unsigned error, key_serial_t keyring);

DESCRIPTION

       keyctl_assume_authority()  assumes  the  authority for the calling thread to deal with and
       instantiate the specified uninstantiated key.

       The calling thread must have the appopriate authorisation  key  resident  in  one  of  its
       keyrings for this to succeed, and that authority must not have been revoked.

       The  authorising  key  is  allocated by request_key() when it needs to invoke userspace to
       generate a key for the requesting process.  This is then attached to one of  the  keyrings
       of the userspace process to which the task of instantiating the key is given:

              requester -> request_key() -> instantiator

       Calling  this  function modifies the way request_key() works when called thereafter by the
       calling (instantiator) thread; once the authority is assumed, the keyrings of the  initial
       process  are  added  to  the search path, using the initial process's UID, GID, groups and
       security context.

       If a thread has multiple instantiations to deal with, it may call this function to  change
       the  authorisation key currently in effect.  Supplying a zero key de-assumes the currently
       assumed authority.

       NOTE!  This is a per-thread setting and not a per-process setting so that a  multithreaded
       process can be used to instantiate several keys at once.

       keyctl_instantiate()  instantiates  the  payload  of  an  uninstantiated key from the data
       specified.  payload and plen specify the data for the new payload.  payload  may  be  NULL
       and  plen  may  be zero if the key type permits that.  The key type may reject the data if
       it's in the wrong format or in some other way invalid.

       keyctl_instantiate_iov() is similar, but the data is passed in an array of  iovec  structs
       instead  of  in  a  flat  buffer.   payload_iov  points  to  the base of the array and ioc
       indicates how many elements there are.  payload_iov may be NULL or  ioc  may  be  zero  to
       indicate that no data is being supplied.

       keyctl_reject()  marks  a  key as negatively instantiated and sets the expiration timer on
       it.  timeout specifies the lifetime of the key in seconds.  error specifies the  error  to
       be  returned  when  a  search hits the key (this is typically EKEYREJECTED, EKEYREVOKED or
       EKEYEXPIRED).  Note that keyctl_reject() falls back to keyctl_negate() if the kernel  does
       not support it.

       keyctl_negate() as keyctl_reject() with an error code of ENOKEY.

       Only  a  key  for  which  authority  has  been  assumed  may be instantiated or negatively
       instantiated, and once instantiated,  the  authorisation  key  will  be  revoked  and  the
       requesting process will be able to resume.

       The  destination keyring, if given, is assumed to belong to the initial requester, and not
       the instantiating process.  Therefore, the special keyring IDs  refer  to  the  requesting
       process's keyrings, not the caller's, and the requester's UID, etc. will be used to access
       them.

       The destination keyring can be zero if no extra link is desired.

       The requester, not the caller, must have write permission on the destination for a link to
       be made there.

RETURN VALUE

       On  success  keyctl_instantiate()  returns 0.  On error, the value -1 will be returned and
       errno will have been set to an appropriate error.

ERRORS

       ENOKEY The key or keyring specified is invalid.

       EKEYEXPIRED
              The keyring specified has expired.

       EKEYREVOKED
              The key or keyring specified had  been  revoked,  or  the  authorisation  has  been
              revoked.

       EINVAL The payload data was invalid.

       ENOMEM Insufficient memory to store the new payload or to expand the destination keyring.

       EDQUOT The  key  quota  for the key's user would be exceeded by increasing the size of the
              key to accommodate the new payload or the key quota for the keyring's user would be
              exceeded by expanding the destination keyring.

       EACCES The key exists, but is not writable by the requester.

LINKING

       This  is  a  library  function that can be found in libkeyutils.  When linking, -lkeyutils
       should be specified to the linker.

SEE ALSO

       keyctl(1),
       add_key(2),
       keyctl(2),
       request_key(2),
       keyctl(3),
       request-key(8)