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[PATCH] Keys: Split key permissions checking into a .c file

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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>
This commit is contained in:
David Howells 2005-10-07 15:07:38 +01:00 committed by Linus Torvalds
parent f1a9badcf6
commit 468ed2b0c8
3 changed files with 76 additions and 86 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

91
include/linux/key-ui.h
View File

@ -38,97 +38,16 @@ struct keyring_list {
struct key *keys[0];
};
/*
* check to see whether permission is granted to use a key in the desired way
*/
extern int key_task_permission(const key_ref_t key_ref,
struct task_struct *context,
key_perm_t perm);
static inline int key_permission(const key_ref_t key_ref, key_perm_t perm)
{
struct key *key = key_ref_to_ptr(key_ref);
key_perm_t kperm;
if (is_key_possessed(key_ref))
kperm = key->perm >> 24;
else if (key->uid == current->fsuid)
kperm = key->perm >> 16;
else if (key->gid != -1 &&
key->perm & KEY_GRP_ALL &&
in_group_p(key->gid)
)
kperm = key->perm >> 8;
else
kperm = key->perm;
kperm = kperm & perm & KEY_ALL;
return kperm == perm;
}
/*
* check to see whether permission is granted to use a key in at least one of
* the desired ways
*/
static inline int key_any_permission(const key_ref_t key_ref, key_perm_t perm)
{
struct key *key = key_ref_to_ptr(key_ref);
key_perm_t kperm;
if (is_key_possessed(key_ref))
kperm = key->perm >> 24;
else if (key->uid == current->fsuid)
kperm = key->perm >> 16;
else if (key->gid != -1 &&
key->perm & KEY_GRP_ALL &&
in_group_p(key->gid)
)
kperm = key->perm >> 8;
else
kperm = key->perm;
kperm = kperm & perm & KEY_ALL;
return kperm != 0;
}
static inline int key_task_groups_search(struct task_struct *tsk, gid_t gid)
{
int ret;
task_lock(tsk);
ret = groups_search(tsk->group_info, gid);
task_unlock(tsk);
return ret;
}
static inline int key_task_permission(const key_ref_t key_ref,
struct task_struct *context,
key_perm_t perm)
{
struct key *key = key_ref_to_ptr(key_ref);
key_perm_t kperm;
if (is_key_possessed(key_ref)) {
kperm = key->perm >> 24;
}
else if (key->uid == context->fsuid) {
kperm = key->perm >> 16;
}
else if (key->gid != -1 &&
key->perm & KEY_GRP_ALL && (
key->gid == context->fsgid ||
key_task_groups_search(context, key->gid)
)
) {
kperm = key->perm >> 8;
}
else {
kperm = key->perm;
}
kperm = kperm & perm & KEY_ALL;
return kperm == perm;
return key_task_permission(key_ref, current, perm);
}
extern key_ref_t lookup_user_key(struct task_struct *context,

1
security/keys/Makefile
View File

@ -6,6 +6,7 @@ obj-y := \
key.o \
keyring.o \
keyctl.o \
permission.o \
process_keys.o \
request_key.o \
request_key_auth.o \

70
security/keys/permission.c Normal file
View File

@ -0,0 +1,70 @@
/* permission.c: key permission determination
*
* Copyright (C) 2005 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.
*/
#include <linux/module.h>
#include "internal.h"
/*****************************************************************************/
/*
* check to see whether permission is granted to use a key in the desired way,
* but permit the security modules to override
*/
int key_task_permission(const key_ref_t key_ref,
struct task_struct *context,
key_perm_t perm)
{
struct key *key;
key_perm_t kperm;
int ret;
key = key_ref_to_ptr(key_ref);
/* use the top 8-bits of permissions for keys the caller possesses */
if (is_key_possessed(key_ref)) {
kperm = key->perm >> 24;
goto use_these_perms;
}
/* use the second 8-bits of permissions for keys the caller owns */
if (key->uid == context->fsuid) {
kperm = key->perm >> 16;
goto use_these_perms;
}
/* use the third 8-bits of permissions for keys the caller has a group
* membership in common with */
if (key->gid != -1 && key->perm & KEY_GRP_ALL) {
if (key->gid == context->fsgid) {
kperm = key->perm >> 8;
goto use_these_perms;
}
task_lock(context);
ret = groups_search(context->group_info, key->gid);
task_unlock(context);
if (ret) {
kperm = key->perm >> 8;
goto use_these_perms;
}
}
/* otherwise use the least-significant 8-bits */
kperm = key->perm;
use_these_perms:
kperm = kperm & perm & KEY_ALL;
return kperm == perm;
} /* end key_task_permission() */
EXPORT_SYMBOL(key_task_permission);