[PATCH] Keys: Split key permissions checking into a .c file
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>
diff --git a/include/linux/key-ui.h b/include/linux/key-ui.h
index 918c34a..7a2e332 100644
--- a/include/linux/key-ui.h
+++ b/include/linux/key-ui.h
@@ -38,97 +38,16 @@
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,
diff --git a/security/keys/Makefile b/security/keys/Makefile
index c392d75..5145adf 100644
--- a/security/keys/Makefile
+++ b/security/keys/Makefile
@@ -6,6 +6,7 @@
key.o \
keyring.o \
keyctl.o \
+ permission.o \
process_keys.o \
request_key.o \
request_key_auth.o \
diff --git a/security/keys/permission.c b/security/keys/permission.c
new file mode 100644
index 0000000..1c36516
--- /dev/null
+++ b/security/keys/permission.c
@@ -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);