Make it possible for a running process (such as gssapid) to be able to
instantiate a key, as was requested by Trond Myklebust for NFS4.
The patch makes the following changes:
(1) A new, optional key type method has been added. This permits a key type
to intercept requests at the point /sbin/request-key is about to be
spawned and do something else with them - passing them over the
rpc_pipefs files or netlink sockets for instance.
The uninstantiated key, the authorisation key and the intended operation
name are passed to the method.
(2) The callout_info is no longer passed as an argument to /sbin/request-key
to prevent unauthorised viewing of this data using ps or by looking in
/proc/pid/cmdline.
This means that the old /sbin/request-key program will not work with the
patched kernel as it will expect to see an extra argument that is no
longer there.
A revised keyutils package will be made available tomorrow.
(3) The callout_info is now attached to the authorisation key. Reading this
key will retrieve the information.
(4) A new field has been added to the task_struct. This holds the
authorisation key currently active for a thread. Searches now look here
for the caller's set of keys rather than looking for an auth key in the
lowest level of the session keyring.
This permits a thread to be servicing multiple requests at once and to
switch between them. Note that this is per-thread, not per-process, and
so is usable in multithreaded programs.
The setting of this field is inherited across fork and exec.
(5) A new keyctl function (KEYCTL_ASSUME_AUTHORITY) has been added that
permits a thread to assume the authority to deal with an uninstantiated
key. Assumption is only permitted if the authorisation key associated
with the uninstantiated key is somewhere in the thread's keyrings.
This function can also clear the assumption.
(6) A new magic key specifier has been added to refer to the currently
assumed authorisation key (KEY_SPEC_REQKEY_AUTH_KEY).
(7) Instantiation will only proceed if the appropriate authorisation key is
assumed first. The assumed authorisation key is discarded if
instantiation is successful.
(8) key_validate() is moved from the file of request_key functions to the
file of permissions functions.
(9) The documentation is updated.
From: <Valdis.Kletnieks@vt.edu>
Build fix.
Signed-off-by: David Howells <dhowells@redhat.com>
Cc: Trond Myklebust <trond.myklebust@fys.uio.no>
Cc: Alexander Zangerl <az@bond.edu.au>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
The attached patch adds LSM hooks for key management facilities. The notable
changes are:
(1) The key struct now supports a security pointer for the use of security
modules. This will permit key labelling and restrictions on which
programs may access a key.
(2) Security modules get a chance to note (or abort) the allocation of a key.
(3) The key permission checking can now be enhanced by the security modules;
the permissions check consults LSM if all other checks bear out.
(4) The key permissions checking functions now return an error code rather
than a boolean value.
(5) An extra permission has been added to govern the modification of
attributes (UID, GID, permissions).
Note that there isn't an LSM hook specifically for each keyctl() operation,
but rather the permissions hook allows control of individual operations based
on the permission request bits.
Key management access control through LSM is enabled by automatically if both
CONFIG_KEYS and CONFIG_SECURITY are enabled.
This should be applied on top of the patch ensubjected:
[PATCH] Keys: Possessor permissions should be additive
Signed-Off-By: David Howells <dhowells@redhat.com>
Signed-off-by: Chris Wright <chrisw@osdl.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This patch makes the possessor permissions on a key additive with
user/group/other permissions on the same key.
This permits extra rights to be granted to the possessor of a key without
taking away any rights conferred by them owning the key or having common group
membership.
Signed-Off-By: David Howells <dhowells@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
The attached patch splits key permissions checking out of key-ui.h and
moves it into a .c file. It's quite large and called quite a lot, and
it's about to get bigger with the addition of LSM support for keys...
key_any_permission() is also discarded as it's no longer used.
Signed-Off-By: David Howells <dhowells@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
David Howells