keys: update the documentation with info about "logon" keys

Acked-by: David Howells <dhowells@redhat.com>
Signed-off-by: Jeff Layton <jlayton@redhat.com>
This commit is contained in:
Jeff Layton 2012-04-25 12:46:50 -04:00
parent af3a3ab296
commit a05a4830a3

View file

@ -123,7 +123,7 @@ KEY SERVICE OVERVIEW
The key service provides a number of features besides keys:
(*) The key service defines two special key types:
(*) The key service defines three special key types:
(+) "keyring"
@ -137,6 +137,18 @@ The key service provides a number of features besides keys:
blobs of data. These can be created, updated and read by userspace,
and aren't intended for use by kernel services.
(+) "logon"
Like a "user" key, a "logon" key has a payload that is an arbitrary
blob of data. It is intended as a place to store secrets which are
accessible to the kernel but not to userspace programs.
The description can be arbitrary, but must be prefixed with a non-zero
length string that describes the key "subclass". The subclass is
separated from the rest of the description by a ':'. "logon" keys can
be created and updated from userspace, but the payload is only
readable from kernel space.
(*) Each process subscribes to three keyrings: a thread-specific keyring, a
process-specific keyring, and a session-specific keyring.