keyctl_search()
recursively searches the
keyring
for a key of the specified
type
and
description.
If found, the key will be attached to the
destination
keyring (if given), and its serial number will be returned.
The source keyring must grant
search
permission to the caller, and for a key to be found, it must also grant
search
permission to the caller. Child keyrings will be only be recursively searched
if they grant
search
permission to the caller as well.
If the destination keyring is
zero,
no attempt will be made to forge a link to the key, and just the serial number
will be returned.
If the destination keyring is given, then the link may only be formed if the
found key grants the caller
link
permission and the destination keyring grants the caller
write
permission.
If the search is successful, and if the destination keyring already contains a
link to a key that matches the specified
type and description,
then that link will be replaced by a link to the found key.
The source keyring and destination keyring serial numbers may be those of
valid keyrings to which the caller has appropriate permission, or they may be
special keyring IDs:
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.
RETURN VALUE
On success
keyctl_search()
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
ENOKEY
One of the keyrings doesn't exist, no key was found by the search, or the only
key found by the search was a negative key.
ENOTDIR
One of the keyrings is a valid key that isn't a keyring.
EKEYEXPIRED
One of the keyrings has expired, or the only key found was expired.
EKEYREVOKED
One of the keyrings has been revoked, or the only key found was revoked.
ENOMEM
Insufficient memory to expand the destination keyring.
EDQUOT
The key quota for this user would be exceeded by creating a link to the found
key in the destination keyring.
EACCES
The source keyring didn't grant
search
permission, the destination keyring didn't grant
write
permission or the found key didn't grant
link
permission to the caller.
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.
