kernel-ark/include/linux/keyctl.h
David Howells b5f545c880 [PATCH] keys: Permit running process to instantiate keys
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>
2006-01-08 20:13:53 -08:00

54 lines
2.4 KiB
C

/* keyctl.h: keyctl command IDs
*
* Copyright (C) 2004 Red Hat, Inc. All Rights Reserved.
* Written by David Howells (dhowells@redhat.com)
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version
* 2 of the License, or (at your option) any later version.
*/
#ifndef _LINUX_KEYCTL_H
#define _LINUX_KEYCTL_H
/* special process keyring shortcut IDs */
#define KEY_SPEC_THREAD_KEYRING -1 /* - key ID for thread-specific keyring */
#define KEY_SPEC_PROCESS_KEYRING -2 /* - key ID for process-specific keyring */
#define KEY_SPEC_SESSION_KEYRING -3 /* - key ID for session-specific keyring */
#define KEY_SPEC_USER_KEYRING -4 /* - key ID for UID-specific keyring */
#define KEY_SPEC_USER_SESSION_KEYRING -5 /* - key ID for UID-session keyring */
#define KEY_SPEC_GROUP_KEYRING -6 /* - key ID for GID-specific keyring */
#define KEY_SPEC_REQKEY_AUTH_KEY -7 /* - key ID for assumed request_key auth key */
/* request-key default keyrings */
#define KEY_REQKEY_DEFL_NO_CHANGE -1
#define KEY_REQKEY_DEFL_DEFAULT 0
#define KEY_REQKEY_DEFL_THREAD_KEYRING 1
#define KEY_REQKEY_DEFL_PROCESS_KEYRING 2
#define KEY_REQKEY_DEFL_SESSION_KEYRING 3
#define KEY_REQKEY_DEFL_USER_KEYRING 4
#define KEY_REQKEY_DEFL_USER_SESSION_KEYRING 5
#define KEY_REQKEY_DEFL_GROUP_KEYRING 6
/* keyctl commands */
#define KEYCTL_GET_KEYRING_ID 0 /* ask for a keyring's ID */
#define KEYCTL_JOIN_SESSION_KEYRING 1 /* join or start named session keyring */
#define KEYCTL_UPDATE 2 /* update a key */
#define KEYCTL_REVOKE 3 /* revoke a key */
#define KEYCTL_CHOWN 4 /* set ownership of a key */
#define KEYCTL_SETPERM 5 /* set perms on a key */
#define KEYCTL_DESCRIBE 6 /* describe a key */
#define KEYCTL_CLEAR 7 /* clear contents of a keyring */
#define KEYCTL_LINK 8 /* link a key into a keyring */
#define KEYCTL_UNLINK 9 /* unlink a key from a keyring */
#define KEYCTL_SEARCH 10 /* search for a key in a keyring */
#define KEYCTL_READ 11 /* read a key or keyring's contents */
#define KEYCTL_INSTANTIATE 12 /* instantiate a partially constructed key */
#define KEYCTL_NEGATE 13 /* negate a partially constructed key */
#define KEYCTL_SET_REQKEY_KEYRING 14 /* set default request-key keyring */
#define KEYCTL_SET_TIMEOUT 15 /* set key timeout */
#define KEYCTL_ASSUME_AUTHORITY 16 /* assume request_key() authorisation */
#endif /* _LINUX_KEYCTL_H */