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authorDavid Howells <dhowells@redhat.com>2005-06-23 22:00:56 -0700
committerLinus Torvalds <torvalds@ppc970.osdl.org>2005-06-24 00:05:19 -0700
commit3e30148c3d524a9c1c63ca28261bc24c457eb07a (patch)
treea2fcc46cc11fe871ad976c07476d934a07313576 /security
parent8589b4e00e352f983259140f25a262d973be6bc5 (diff)
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[PATCH] Keys: Make request-key create an authorisation key
The attached patch makes the following changes: (1) There's a new special key type called ".request_key_auth". This is an authorisation key for when one process requests a key and another process is started to construct it. This type of key cannot be created by the user; nor can it be requested by kernel services. Authorisation keys hold two references: (a) Each refers to a key being constructed. When the key being constructed is instantiated the authorisation key is revoked, rendering it of no further use. (b) The "authorising process". This is either: (i) the process that called request_key(), or: (ii) if the process that called request_key() itself had an authorisation key in its session keyring, then the authorising process referred to by that authorisation key will also be referred to by the new authorisation key. This means that the process that initiated a chain of key requests will authorise the lot of them, and will, by default, wind up with the keys obtained from them in its keyrings. (2) request_key() creates an authorisation key which is then passed to /sbin/request-key in as part of a new session keyring. (3) When request_key() is searching for a key to hand back to the caller, if it comes across an authorisation key in the session keyring of the calling process, it will also search the keyrings of the process specified therein and it will use the specified process's credentials (fsuid, fsgid, groups) to do that rather than the calling process's credentials. This allows a process started by /sbin/request-key to find keys belonging to the authorising process. (4) A key can be read, even if the process executing KEYCTL_READ doesn't have direct read or search permission if that key is contained within the keyrings of a process specified by an authorisation key found within the calling process's session keyring, and is searchable using the credentials of the authorising process. This allows a process started by /sbin/request-key to read keys belonging to the authorising process. (5) The magic KEY_SPEC_*_KEYRING key IDs when passed to KEYCTL_INSTANTIATE or KEYCTL_NEGATE will specify a keyring of the authorising process, rather than the process doing the instantiation. (6) One of the process keyrings can be nominated as the default to which request_key() should attach new keys if not otherwise specified. This is done with KEYCTL_SET_REQKEY_KEYRING and one of the KEY_REQKEY_DEFL_* constants. The current setting can also be read using this call. (7) request_key() is partially interruptible. If it is waiting for another process to finish constructing a key, it can be interrupted. This permits a request-key cycle to be broken without recourse to rebooting. Signed-Off-By: David Howells <dhowells@redhat.com> Signed-Off-By: Benoit Boissinot <benoit.boissinot@ens-lyon.org> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Diffstat (limited to 'security')
-rw-r--r--security/keys/Makefile5
-rw-r--r--security/keys/compat.c7
-rw-r--r--security/keys/internal.h45
-rw-r--r--security/keys/key.c24
-rw-r--r--security/keys/keyctl.c176
-rw-r--r--security/keys/keyring.c67
-rw-r--r--security/keys/process_keys.c179
-rw-r--r--security/keys/request_key.c182
-rw-r--r--security/keys/request_key_auth.c180
9 files changed, 685 insertions, 180 deletions
diff --git a/security/keys/Makefile b/security/keys/Makefile
index ddb495d6506..c392d750b20 100644
--- a/security/keys/Makefile
+++ b/security/keys/Makefile
@@ -7,8 +7,9 @@ obj-y := \
keyring.o \
keyctl.o \
process_keys.o \
- user_defined.o \
- request_key.o
+ request_key.o \
+ request_key_auth.o \
+ user_defined.o
obj-$(CONFIG_KEYS_COMPAT) += compat.o
obj-$(CONFIG_PROC_FS) += proc.o
diff --git a/security/keys/compat.c b/security/keys/compat.c
index aff8b22dcb5..3303673c636 100644
--- a/security/keys/compat.c
+++ b/security/keys/compat.c
@@ -1,6 +1,6 @@
/* compat.c: 32-bit compatibility syscall for 64-bit systems
*
- * Copyright (C) 2004 Red Hat, Inc. All Rights Reserved.
+ * Copyright (C) 2004-5 Red Hat, Inc. All Rights Reserved.
* Written by David Howells (dhowells@redhat.com)
*
* This program is free software; you can redistribute it and/or
@@ -24,7 +24,7 @@
* - if you can, you should call sys_keyctl directly
*/
asmlinkage long compat_sys_keyctl(u32 option,
- u32 arg2, u32 arg3, u32 arg4, u32 arg5)
+ u32 arg2, u32 arg3, u32 arg4, u32 arg5)
{
switch (option) {
case KEYCTL_GET_KEYRING_ID:
@@ -71,6 +71,9 @@ asmlinkage long compat_sys_keyctl(u32 option,
case KEYCTL_NEGATE:
return keyctl_negate_key(arg2, arg3, arg4);
+ case KEYCTL_SET_REQKEY_KEYRING:
+ return keyctl_set_reqkey_keyring(arg2);
+
default:
return -EOPNOTSUPP;
}
diff --git a/security/keys/internal.h b/security/keys/internal.h
index 67b2b93a748..46c8602661c 100644
--- a/security/keys/internal.h
+++ b/security/keys/internal.h
@@ -1,6 +1,6 @@
/* internal.h: authentication token and access key management internal defs
*
- * Copyright (C) 2003 Red Hat, Inc. All Rights Reserved.
+ * Copyright (C) 2003-5 Red Hat, Inc. All Rights Reserved.
* Written by David Howells (dhowells@redhat.com)
*
* This program is free software; you can redistribute it and/or
@@ -15,6 +15,16 @@
#include <linux/key.h>
#include <linux/key-ui.h>
+#if 0
+#define kenter(FMT, a...) printk("==> %s("FMT")\n",__FUNCTION__ , ## a)
+#define kleave(FMT, a...) printk("<== %s()"FMT"\n",__FUNCTION__ , ## a)
+#define kdebug(FMT, a...) printk(FMT"\n" , ## a)
+#else
+#define kenter(FMT, a...) do {} while(0)
+#define kleave(FMT, a...) do {} while(0)
+#define kdebug(FMT, a...) do {} while(0)
+#endif
+
extern struct key_type key_type_dead;
extern struct key_type key_type_user;
@@ -66,20 +76,46 @@ extern struct key *__keyring_search_one(struct key *keyring,
const char *description,
key_perm_t perm);
+extern struct key *keyring_search_instkey(struct key *keyring,
+ key_serial_t target_id);
+
typedef int (*key_match_func_t)(const struct key *, const void *);
extern struct key *keyring_search_aux(struct key *keyring,
+ struct task_struct *tsk,
struct key_type *type,
const void *description,
key_match_func_t match);
-extern struct key *search_process_keyrings_aux(struct key_type *type,
- const void *description,
- key_match_func_t match);
+extern struct key *search_process_keyrings(struct key_type *type,
+ const void *description,
+ key_match_func_t match,
+ struct task_struct *tsk);
extern struct key *find_keyring_by_name(const char *name, key_serial_t bound);
extern int install_thread_keyring(struct task_struct *tsk);
+extern int install_process_keyring(struct task_struct *tsk);
+
+extern struct key *request_key_and_link(struct key_type *type,
+ const char *description,
+ const char *callout_info,
+ struct key *dest_keyring);
+
+/*
+ * request_key authorisation
+ */
+struct request_key_auth {
+ struct key *target_key;
+ struct task_struct *context;
+ pid_t pid;
+};
+
+extern struct key_type key_type_request_key_auth;
+extern struct key *request_key_auth_new(struct key *target,
+ struct key **_rkakey);
+
+extern struct key *key_get_instantiation_authkey(key_serial_t target_id);
/*
* keyctl functions
@@ -100,6 +136,7 @@ extern long keyctl_setperm_key(key_serial_t, key_perm_t);
extern long keyctl_instantiate_key(key_serial_t, const void __user *,
size_t, key_serial_t);
extern long keyctl_negate_key(key_serial_t, unsigned, key_serial_t);
+extern long keyctl_set_reqkey_keyring(int);
/*
diff --git a/security/keys/key.c b/security/keys/key.c
index 1fdfccb3fe4..3304d37bb37 100644
--- a/security/keys/key.c
+++ b/security/keys/key.c
@@ -1,6 +1,6 @@
/* key.c: basic authentication token and access key management
*
- * Copyright (C) 2004 Red Hat, Inc. All Rights Reserved.
+ * Copyright (C) 2004-5 Red Hat, Inc. All Rights Reserved.
* Written by David Howells (dhowells@redhat.com)
*
* This program is free software; you can redistribute it and/or
@@ -391,7 +391,8 @@ EXPORT_SYMBOL(key_payload_reserve);
static int __key_instantiate_and_link(struct key *key,
const void *data,
size_t datalen,
- struct key *keyring)
+ struct key *keyring,
+ struct key *instkey)
{
int ret, awaken;
@@ -419,6 +420,10 @@ static int __key_instantiate_and_link(struct key *key,
/* and link it into the destination keyring */
if (keyring)
ret = __key_link(keyring, key);
+
+ /* disable the authorisation key */
+ if (instkey)
+ key_revoke(instkey);
}
}
@@ -439,19 +444,21 @@ static int __key_instantiate_and_link(struct key *key,
int key_instantiate_and_link(struct key *key,
const void *data,
size_t datalen,
- struct key *keyring)
+ struct key *keyring,
+ struct key *instkey)
{
int ret;
if (keyring)
down_write(&keyring->sem);
- ret = __key_instantiate_and_link(key, data, datalen, keyring);
+ ret = __key_instantiate_and_link(key, data, datalen, keyring, instkey);
if (keyring)
up_write(&keyring->sem);
return ret;
+
} /* end key_instantiate_and_link() */
EXPORT_SYMBOL(key_instantiate_and_link);
@@ -462,7 +469,8 @@ EXPORT_SYMBOL(key_instantiate_and_link);
*/
int key_negate_and_link(struct key *key,
unsigned timeout,
- struct key *keyring)
+ struct key *keyring,
+ struct key *instkey)
{
struct timespec now;
int ret, awaken;
@@ -495,6 +503,10 @@ int key_negate_and_link(struct key *key,
/* and link it into the destination keyring */
if (keyring)
ret = __key_link(keyring, key);
+
+ /* disable the authorisation key */
+ if (instkey)
+ key_revoke(instkey);
}
up_write(&key_construction_sem);
@@ -781,7 +793,7 @@ struct key *key_create_or_update(struct key *keyring,
}
/* instantiate it and link it into the target keyring */
- ret = __key_instantiate_and_link(key, payload, plen, keyring);
+ ret = __key_instantiate_and_link(key, payload, plen, keyring, NULL);
if (ret < 0) {
key_put(key);
key = ERR_PTR(ret);
diff --git a/security/keys/keyctl.c b/security/keys/keyctl.c
index cedb7326de2..fea262860ea 100644
--- a/security/keys/keyctl.c
+++ b/security/keys/keyctl.c
@@ -1,6 +1,6 @@
/* keyctl.c: userspace keyctl operations
*
- * Copyright (C) 2004 Red Hat, Inc. All Rights Reserved.
+ * Copyright (C) 2004-5 Red Hat, Inc. All Rights Reserved.
* Written by David Howells (dhowells@redhat.com)
*
* This program is free software; you can redistribute it and/or
@@ -49,6 +49,13 @@ asmlinkage long sys_add_key(const char __user *_type,
goto error;
type[31] = '\0';
+ if (!type[0])
+ goto error;
+
+ ret = -EPERM;
+ if (type[0] == '.')
+ goto error;
+
ret = -EFAULT;
dlen = strnlen_user(_description, PAGE_SIZE - 1);
if (dlen <= 0)
@@ -82,7 +89,7 @@ asmlinkage long sys_add_key(const char __user *_type,
}
/* find the target keyring (which must be writable) */
- keyring = lookup_user_key(ringid, 1, 0, KEY_WRITE);
+ keyring = lookup_user_key(NULL, ringid, 1, 0, KEY_WRITE);
if (IS_ERR(keyring)) {
ret = PTR_ERR(keyring);
goto error3;
@@ -181,7 +188,7 @@ asmlinkage long sys_request_key(const char __user *_type,
/* get the destination keyring if specified */
dest = NULL;
if (destringid) {
- dest = lookup_user_key(destringid, 1, 0, KEY_WRITE);
+ dest = lookup_user_key(NULL, destringid, 1, 0, KEY_WRITE);
if (IS_ERR(dest)) {
ret = PTR_ERR(dest);
goto error3;
@@ -196,23 +203,15 @@ asmlinkage long sys_request_key(const char __user *_type,
}
/* do the search */
- key = request_key(ktype, description, callout_info);
+ key = request_key_and_link(ktype, description, callout_info, dest);
if (IS_ERR(key)) {
ret = PTR_ERR(key);
goto error5;
}
- /* link the resulting key to the destination keyring */
- if (dest) {
- ret = key_link(dest, key);
- if (ret < 0)
- goto error6;
- }
-
ret = key->serial;
- error6:
- key_put(key);
+ key_put(key);
error5:
key_type_put(ktype);
error4:
@@ -237,7 +236,7 @@ long keyctl_get_keyring_ID(key_serial_t id, int create)
struct key *key;
long ret;
- key = lookup_user_key(id, create, 0, KEY_SEARCH);
+ key = lookup_user_key(NULL, id, create, 0, KEY_SEARCH);
if (IS_ERR(key)) {
ret = PTR_ERR(key);
goto error;
@@ -324,7 +323,7 @@ long keyctl_update_key(key_serial_t id,
}
/* find the target key (which must be writable) */
- key = lookup_user_key(id, 0, 0, KEY_WRITE);
+ key = lookup_user_key(NULL, id, 0, 0, KEY_WRITE);
if (IS_ERR(key)) {
ret = PTR_ERR(key);
goto error2;
@@ -352,7 +351,7 @@ long keyctl_revoke_key(key_serial_t id)
struct key *key;
long ret;
- key = lookup_user_key(id, 0, 0, KEY_WRITE);
+ key = lookup_user_key(NULL, id, 0, 0, KEY_WRITE);
if (IS_ERR(key)) {
ret = PTR_ERR(key);
goto error;
@@ -378,7 +377,7 @@ long keyctl_keyring_clear(key_serial_t ringid)
struct key *keyring;
long ret;
- keyring = lookup_user_key(ringid, 1, 0, KEY_WRITE);
+ keyring = lookup_user_key(NULL, ringid, 1, 0, KEY_WRITE);
if (IS_ERR(keyring)) {
ret = PTR_ERR(keyring);
goto error;
@@ -404,13 +403,13 @@ long keyctl_keyring_link(key_serial_t id, key_serial_t ringid)
struct key *keyring, *key;
long ret;
- keyring = lookup_user_key(ringid, 1, 0, KEY_WRITE);
+ keyring = lookup_user_key(NULL, ringid, 1, 0, KEY_WRITE);
if (IS_ERR(keyring)) {
ret = PTR_ERR(keyring);
goto error;
}
- key = lookup_user_key(id, 1, 0, KEY_LINK);
+ key = lookup_user_key(NULL, id, 1, 0, KEY_LINK);
if (IS_ERR(key)) {
ret = PTR_ERR(key);
goto error2;
@@ -438,13 +437,13 @@ long keyctl_keyring_unlink(key_serial_t id, key_serial_t ringid)
struct key *keyring, *key;
long ret;
- keyring = lookup_user_key(ringid, 0, 0, KEY_WRITE);
+ keyring = lookup_user_key(NULL, ringid, 0, 0, KEY_WRITE);
if (IS_ERR(keyring)) {
ret = PTR_ERR(keyring);
goto error;
}
- key = lookup_user_key(id, 0, 0, 0);
+ key = lookup_user_key(NULL, id, 0, 0, 0);
if (IS_ERR(key)) {
ret = PTR_ERR(key);
goto error2;
@@ -475,16 +474,29 @@ long keyctl_describe_key(key_serial_t keyid,
char __user *buffer,
size_t buflen)
{
- struct key *key;
+ struct key *key, *instkey;
char *tmpbuf;
long ret;
- key = lookup_user_key(keyid, 0, 1, KEY_VIEW);
+ key = lookup_user_key(NULL, keyid, 0, 1, KEY_VIEW);
if (IS_ERR(key)) {
+ /* viewing a key under construction is permitted if we have the
+ * authorisation token handy */
+ if (PTR_ERR(key) == -EACCES) {
+ instkey = key_get_instantiation_authkey(keyid);
+ if (!IS_ERR(instkey)) {
+ key_put(instkey);
+ key = lookup_user_key(NULL, keyid, 0, 1, 0);
+ if (!IS_ERR(key))
+ goto okay;
+ }
+ }
+
ret = PTR_ERR(key);
goto error;
}
+okay:
/* calculate how much description we're going to return */
ret = -ENOMEM;
tmpbuf = kmalloc(PAGE_SIZE, GFP_KERNEL);
@@ -568,7 +580,7 @@ long keyctl_keyring_search(key_serial_t ringid,
goto error2;
/* get the keyring at which to begin the search */
- keyring = lookup_user_key(ringid, 0, 0, KEY_SEARCH);
+ keyring = lookup_user_key(NULL, ringid, 0, 0, KEY_SEARCH);
if (IS_ERR(keyring)) {
ret = PTR_ERR(keyring);
goto error2;
@@ -577,7 +589,7 @@ long keyctl_keyring_search(key_serial_t ringid,
/* get the destination keyring if specified */
dest = NULL;
if (destringid) {
- dest = lookup_user_key(destringid, 1, 0, KEY_WRITE);
+ dest = lookup_user_key(NULL, destringid, 1, 0, KEY_WRITE);
if (IS_ERR(dest)) {
ret = PTR_ERR(dest);
goto error3;
@@ -656,24 +668,23 @@ long keyctl_read_key(key_serial_t keyid, char __user *buffer, size_t buflen)
long ret;
/* find the key first */
- key = lookup_user_key(keyid, 0, 0, 0);
+ key = lookup_user_key(NULL, keyid, 0, 0, 0);
if (!IS_ERR(key)) {
/* see if we can read it directly */
if (key_permission(key, KEY_READ))
goto can_read_key;
- /* can't; see if it's searchable from this process's
- * keyrings */
- ret = -ENOKEY;
- if (key_permission(key, KEY_SEARCH)) {
- /* okay - we do have search permission on the key
- * itself, but do we have the key? */
- skey = search_process_keyrings_aux(key->type, key,
- keyctl_read_key_same);
- if (!IS_ERR(skey))
- goto can_read_key2;
- }
-
+ /* we can't; see if it's searchable from this process's
+ * keyrings
+ * - we automatically take account of the fact that it may be
+ * dangling off an instantiation key
+ */
+ skey = search_process_keyrings(key->type, key,
+ keyctl_read_key_same, current);
+ if (!IS_ERR(skey))
+ goto can_read_key2;
+
+ ret = PTR_ERR(skey);
goto error2;
}
@@ -719,7 +730,7 @@ long keyctl_chown_key(key_serial_t id, uid_t uid, gid_t gid)
if (uid == (uid_t) -1 && gid == (gid_t) -1)
goto error;
- key = lookup_user_key(id, 1, 1, 0);
+ key = lookup_user_key(NULL, id, 1, 1, 0);
if (IS_ERR(key)) {
ret = PTR_ERR(key);
goto error;
@@ -776,7 +787,7 @@ long keyctl_setperm_key(key_serial_t id, key_perm_t perm)
if (perm & ~(KEY_USR_ALL | KEY_GRP_ALL | KEY_OTH_ALL))
goto error;
- key = lookup_user_key(id, 1, 1, 0);
+ key = lookup_user_key(NULL, id, 1, 1, 0);
if (IS_ERR(key)) {
ret = PTR_ERR(key);
goto error;
@@ -809,7 +820,8 @@ long keyctl_instantiate_key(key_serial_t id,
size_t plen,
key_serial_t ringid)
{
- struct key *key, *keyring;
+ struct request_key_auth *rka;
+ struct key *instkey, *keyring;
void *payload;
long ret;
@@ -831,18 +843,21 @@ long keyctl_instantiate_key(key_serial_t id,
goto error2;
}
- /* find the target key (which must be writable) */
- key = lookup_user_key(id, 0, 1, KEY_WRITE);
- if (IS_ERR(key)) {
- ret = PTR_ERR(key);
+ /* find the instantiation authorisation key */
+ instkey = key_get_instantiation_authkey(id);
+ if (IS_ERR(instkey)) {
+ ret = PTR_ERR(instkey);
goto error2;
}
- /* find the destination keyring if present (which must also be
- * writable) */
+ rka = instkey->payload.data;
+
+ /* find the destination keyring amongst those belonging to the
+ * requesting task */
keyring = NULL;
if (ringid) {
- keyring = lookup_user_key(ringid, 1, 0, KEY_WRITE);
+ keyring = lookup_user_key(rka->context, ringid, 1, 0,
+ KEY_WRITE);
if (IS_ERR(keyring)) {
ret = PTR_ERR(keyring);
goto error3;
@@ -850,11 +865,12 @@ long keyctl_instantiate_key(key_serial_t id,
}
/* instantiate the key and link it into a keyring */
- ret = key_instantiate_and_link(key, payload, plen, keyring);
+ ret = key_instantiate_and_link(rka->target_key, payload, plen,
+ keyring, instkey);
key_put(keyring);
error3:
- key_put(key);
+ key_put(instkey);
error2:
kfree(payload);
error:
@@ -869,21 +885,24 @@ long keyctl_instantiate_key(key_serial_t id,
*/
long keyctl_negate_key(key_serial_t id, unsigned timeout, key_serial_t ringid)
{
- struct key *key, *keyring;
+ struct request_key_auth *rka;
+ struct key *instkey, *keyring;
long ret;
- /* find the target key (which must be writable) */
- key = lookup_user_key(id, 0, 1, KEY_WRITE);
- if (IS_ERR(key)) {
- ret = PTR_ERR(key);
+ /* find the instantiation authorisation key */
+ instkey = key_get_instantiation_authkey(id);
+ if (IS_ERR(instkey)) {
+ ret = PTR_ERR(instkey);
goto error;
}
+ rka = instkey->payload.data;
+
/* find the destination keyring if present (which must also be
* writable) */
keyring = NULL;
if (ringid) {
- keyring = lookup_user_key(ringid, 1, 0, KEY_WRITE);
+ keyring = lookup_user_key(NULL, ringid, 1, 0, KEY_WRITE);
if (IS_ERR(keyring)) {
ret = PTR_ERR(keyring);
goto error2;
@@ -891,11 +910,11 @@ long keyctl_negate_key(key_serial_t id, unsigned timeout, key_serial_t ringid)
}
/* instantiate the key and link it into a keyring */
- ret = key_negate_and_link(key, timeout, keyring);
+ ret = key_negate_and_link(rka->target_key, timeout, keyring, instkey);
key_put(keyring);
error2:
- key_put(key);
+ key_put(instkey);
error:
return ret;
@@ -903,6 +922,44 @@ long keyctl_negate_key(key_serial_t id, unsigned timeout, key_serial_t ringid)
/*****************************************************************************/
/*
+ * set the default keyring in which request_key() will cache keys
+ * - return the old setting
+ */
+long keyctl_set_reqkey_keyring(int reqkey_defl)
+{
+ int ret;
+
+ switch (reqkey_defl) {
+ case KEY_REQKEY_DEFL_THREAD_KEYRING:
+ ret = install_thread_keyring(current);
+ if (ret < 0)
+ return ret;
+ goto set;
+
+ case KEY_REQKEY_DEFL_PROCESS_KEYRING:
+ ret = install_process_keyring(current);
+ if (ret < 0)
+ return ret;
+
+ case KEY_REQKEY_DEFL_DEFAULT:
+ case KEY_REQKEY_DEFL_SESSION_KEYRING:
+ case KEY_REQKEY_DEFL_USER_KEYRING:
+ case KEY_REQKEY_DEFL_USER_SESSION_KEYRING:
+ set:
+ current->jit_keyring = reqkey_defl;
+
+ case KEY_REQKEY_DEFL_NO_CHANGE:
+ return current->jit_keyring;
+
+ case KEY_REQKEY_DEFL_GROUP_KEYRING:
+ default:
+ return -EINVAL;
+ }
+
+} /* end keyctl_set_reqkey_keyring() */
+
+/*****************************************************************************/
+/*
* the key control system call
*/
asmlinkage long sys_keyctl(int option, unsigned long arg2, unsigned long arg3,
@@ -971,6 +1028,9 @@ asmlinkage long sys_keyctl(int option, unsigned long arg2, unsigned long arg3,
(unsigned) arg3,
(key_serial_t) arg4);
+ case KEYCTL_SET_REQKEY_KEYRING:
+ return keyctl_set_reqkey_keyring(arg2);
+
default:
return -EOPNOTSUPP;
}
diff --git a/security/keys/keyring.c b/security/keys/keyring.c
index c9a5de19748..90a551e4da6 100644
--- a/security/keys/keyring.c
+++ b/security/keys/keyring.c
@@ -1,6 +1,6 @@
/* keyring.c: keyring handling
*
- * Copyright (C) 2004 Red Hat, Inc. All Rights Reserved.
+ * Copyright (C) 2004-5 Red Hat, Inc. All Rights Reserved.
* Written by David Howells (dhowells@redhat.com)
*
* This program is free software; you can redistribute it and/or
@@ -308,7 +308,7 @@ struct key *keyring_alloc(const char *description, uid_t uid, gid_t gid,
uid, gid, KEY_USR_ALL, not_in_quota);
if (!IS_ERR(keyring)) {
- ret = key_instantiate_and_link(keyring, NULL, 0, dest);
+ ret = key_instantiate_and_link(keyring, NULL, 0, dest, NULL);
if (ret < 0) {
key_put(keyring);
keyring = ERR_PTR(ret);
@@ -326,11 +326,12 @@ struct key *keyring_alloc(const char *description, uid_t uid, gid_t gid,
* - we only find keys on which we have search permission
* - we use the supplied match function to see if the description (or other
* feature of interest) matches
- * - we readlock the keyrings as we search down the tree
+ * - we rely on RCU to prevent the keyring lists from disappearing on us
* - we return -EAGAIN if we didn't find any matching key
* - we return -ENOKEY if we only found negative matching keys
*/
struct key *keyring_search_aux(struct key *keyring,
+ struct task_struct *context,
struct key_type *type,
const void *description,
key_match_func_t match)
@@ -352,7 +353,7 @@ struct key *keyring_search_aux(struct key *keyring,
/* top keyring must have search permission to begin the search */
key = ERR_PTR(-EACCES);
- if (!key_permission(keyring, KEY_SEARCH))
+ if (!key_task_permission(keyring, context, KEY_SEARCH))
goto error;
key = ERR_PTR(-ENOTDIR);
@@ -392,7 +393,7 @@ struct key *keyring_search_aux(struct key *keyring,
continue;
/* key must have search permissions */
- if (!key_permission(key, KEY_SEARCH))
+ if (!key_task_permission(key, context, KEY_SEARCH))
continue;
/* we set a different error code if we find a negative key */
@@ -418,7 +419,7 @@ struct key *keyring_search_aux(struct key *keyring,
if (sp >= KEYRING_SEARCH_MAX_DEPTH)
continue;
- if (!key_permission(key, KEY_SEARCH))
+ if (!key_task_permission(key, context, KEY_SEARCH))
continue;
/* stack the current position */
@@ -468,7 +469,11 @@ struct key *keyring_search(struct key *keyring,
struct key_type *type,
const char *description)
{
- return keyring_search_aux(keyring, type, description, type->match);
+ if (!type->match)
+ return ERR_PTR(-ENOKEY);
+
+ return keyring_search_aux(keyring, current,
+ type, description, type->match);
} /* end keyring_search() */
@@ -496,7 +501,8 @@ struct key *__keyring_search_one(struct key *keyring,
key = klist->keys[loop];
if (key->type == ktype &&
- key->type->match(key, description) &&
+ (!key->type->match ||
+ key->type->match(key, description)) &&
key_permission(key, perm) &&
!test_bit(KEY_FLAG_REVOKED, &key->flags)
)
@@ -517,6 +523,51 @@ struct key *__keyring_search_one(struct key *keyring,
/*****************************************************************************/
/*
+ * search for an instantiation authorisation key matching a target key
+ * - the RCU read lock must be held by the caller
+ * - a target_id of zero specifies any valid token
+ */
+struct key *keyring_search_instkey(struct key *keyring,
+ key_serial_t target_id)
+{
+ struct request_key_auth *rka;
+ struct keyring_list *klist;
+ struct key *instkey;
+ int loop;
+
+ klist = rcu_dereference(keyring->payload.subscriptions);
+ if (klist) {
+ for (loop = 0; loop < klist->nkeys; loop++) {
+ instkey = klist->keys[loop];
+
+ if (instkey->type != &key_type_request_key_auth)
+ continue;
+
+ rka = instkey->payload.data;
+ if (target_id && rka->target_key->serial != target_id)
+ continue;
+
+ /* the auth key is revoked during instantiation */
+ if (!test_bit(KEY_FLAG_REVOKED, &instkey->flags))
+ goto found;
+
+ instkey = ERR_PTR(-EKEYREVOKED);
+ goto error;
+ }
+ }
+
+ instkey = ERR_PTR(-EACCES);
+ goto error;
+
+found:
+ atomic_inc(&instkey->usage);
+error:
+ return instkey;
+
+} /* end keyring_search_instkey() */
+
+/*****************************************************************************/
+/*
* find a keyring with the specified name
* - all named keyrings are searched
* - only find keyrings with search permission for the process
diff --git a/security/keys/process_keys.c b/security/keys/process_keys.c
index 972e3017268..34db087bbcc 100644
--- a/security/keys/process_keys.c
+++ b/security/keys/process_keys.c
@@ -165,7 +165,7 @@ int install_thread_keyring(struct task_struct *tsk)
/*
* make sure a process keyring is installed
*/
-static int install_process_keyring(struct task_struct *tsk)
+int install_process_keyring(struct task_struct *tsk)
{
unsigned long flags;
struct key *keyring;
@@ -376,12 +376,13 @@ void key_fsgid_changed(struct task_struct *tsk)
* - we return -EAGAIN if we didn't find any matching key
* - we return -ENOKEY if we found only negative matching keys
*/
-struct key *search_process_keyrings_aux(struct key_type *type,
- const void *description,
- key_match_func_t match)
+struct key *search_process_keyrings(struct key_type *type,
+ const void *description,
+ key_match_func_t match,
+ struct task_struct *context)
{
- struct task_struct *tsk = current;
- struct key *key, *ret, *err;
+ struct request_key_auth *rka;
+ struct key *key, *ret, *err, *instkey;
/* we want to return -EAGAIN or -ENOKEY if any of the keyrings were
* searchable, but we failed to find a key or we found a negative key;
@@ -395,9 +396,9 @@ struct key *search_process_keyrings_aux(struct key_type *type,
err = ERR_PTR(-EAGAIN);
/* search the thread keyring first */
- if (tsk->thread_keyring) {
- key = keyring_search_aux(tsk->thread_keyring, type,
- description, match);
+ if (context->thread_keyring) {
+ key = keyring_search_aux(context->thread_keyring,
+ context, type, description, match);
if (!IS_ERR(key))
goto found;
@@ -415,9 +416,9 @@ struct key *search_process_keyrings_aux(struct key_type *type,
}
/* search the process keyring second */
- if (tsk->signal->process_keyring) {
- key = keyring_search_aux(tsk->signal->process_keyring,
- type, description, match);
+ if (context->signal->process_keyring) {
+ key = keyring_search_aux(context->signal->process_keyring,
+ context, type, description, match);
if (!IS_ERR(key))
goto found;
@@ -434,53 +435,93 @@ struct key *search_process_keyrings_aux(struct key_type *type,
}
}
- /* search the session keyring last */
- if (tsk->signal->session_keyring) {
+ /* search the session keyring */
+ if (context->signal->session_keyring) {
rcu_read_lock();
key = keyring_search_aux(
- rcu_dereference(tsk->signal->session_keyring),
- type, description, match);
+ rcu_dereference(context->signal->session_keyring),
+ context, type, description, match);
rcu_read_unlock();
+
+ if (!IS_ERR(key))
+ goto found;
+
+ switch (PTR_ERR(key)) {
+ case -EAGAIN: /* no key */
+ if (ret)
+ break;
+ case -ENOKEY: /* negative key */
+ ret = key;
+ break;
+ default:
+ err = key;
+ break;
+ }
+
+ /* if this process has a session keyring and that has an
+ * instantiation authorisation key in the bottom level, then we
+ * also search the keyrings of the process mentioned there */
+ if (context != current)
+ goto no_key;
+
+ rcu_read_lock();
+ instkey = __keyring_search_one(
+ rcu_dereference(context->signal->session_keyring),
+ &key_type_request_key_auth, NULL, 0);
+ rcu_read_unlock();
+
+ if (IS_ERR(instkey))
+ goto no_key;
+
+ rka = instkey->payload.data;
+
+ key = search_process_keyrings(type, description, match,
+ rka->context);
+ key_put(instkey);
+
+ if (!IS_ERR(key))
+ goto found;
+
+ switch (PTR_ERR(key)) {
+ case -EAGAIN: /* no key */
+ if (ret)
+ break;
+ case -ENOKEY: /* negative key */
+ ret = key;
+ break;
+ default:
+ err = key;
+ break;
+ }
}
+ /* or search the user-session keyring */
else {
- key = keyring_search_aux(tsk->user->session_keyring,
- type, description, match);
- }
-
- if (!IS_ERR(key))
- goto found;
+ key = keyring_search_aux(context->user->session_keyring,
+ context, type, description, match);
+ if (!IS_ERR(key))
+ goto found;
- switch (PTR_ERR(key)) {
- case -EAGAIN: /* no key */
- if (ret)
+ switch (PTR_ERR(key)) {
+ case -EAGAIN: /* no key */
+ if (ret)
+ break;
+ case -ENOKEY: /* negative key */
+ ret = key;
break;
- case -ENOKEY: /* negative key */
- ret = key;
- break;
- default:
- err = key;
- break;
+ default:
+ err = key;
+ break;
+ }
}
+
+no_key:
/* no key - decide on the error we're going to go for */
key = ret ? ret : err;
- found:
+found:
return key;
-} /* end search_process_keyrings_aux() */
-
-/*****************************************************************************/
-/*
- * search the process keyrings for the first matching key
- * - we return -EAGAIN if we didn't find any matching key
- * - we return -ENOKEY if we found only negative matching keys
- */
-struct key *search_process_keyrings(struct key_type *type,
- const char *description)
-{
- return search_process_keyrings_aux(type, description, type->match);
-
} /* end search_process_keyrings() */
/*****************************************************************************/
@@ -489,72 +530,73 @@ struct key *search_process_keyrings(struct key_type *type,
* - don't create special keyrings unless so requested
* - partially constructed keys aren't found unless requested
*/
-struct key *lookup_user_key(key_serial_t id, int create, int partial,
- key_perm_t perm)
+struct key *lookup_user_key(struct task_struct *context, key_serial_t id,
+ int create, int partial, key_perm_t perm)
{
- struct task_struct *tsk = current;
- unsigned long flags;
struct key *key;
int ret;
+ if (!context)
+ context = current;
+
key = ERR_PTR(-ENOKEY);
switch (id) {
case KEY_SPEC_THREAD_KEYRING:
- if (!tsk->thread_keyring) {
+ if (!context->thread_keyring) {
if (!create)
goto error;
- ret = install_thread_keyring(tsk);
+ ret = install_thread_keyring(context);
if (ret < 0) {
key = ERR_PTR(ret);
goto error;
}
}
- key = tsk->thread_keyring;
+ key = context->thread_keyring;
atomic_inc(&key->usage);
break;
case KEY_SPEC_PROCESS_KEYRING:
- if (!tsk->signal->process_keyring) {
+ if (!context->signal->process_keyring) {
if (!create)
goto error;
- ret = install_process_keyring(tsk);
+ ret = install_process_keyring(context);
if (ret < 0) {
key = ERR_PTR(ret);
goto error;
}
}
- key = tsk->signal->process_keyring;
+ key = context->signal->process_keyring;
atomic_inc(&key->usage);
break;
case KEY_SPEC_SESSION_KEYRING:
- if (!tsk->signal->session_keyring) {
+ if (!context->signal->session_keyring) {
/* always install a session keyring upon access if one
* doesn't exist yet */
ret = install_session_keyring(
- tsk, tsk->user->session_keyring);
+ context, context->user->session_keyring);
if (ret < 0)
goto error;
}
- spin_lock_irqsave(&tsk->sighand->siglock, flags);
- key = tsk->signal->session_keyring;
+ rcu_read_lock();
+ key = rcu_dereference(context->signal->session_keyring);
atomic_inc(&key->usage);
- spin_unlock_irqrestore(&tsk->sighand->siglock, flags);
+ rcu_read_unlock();
break;
case KEY_SPEC_USER_KEYRING:
- key = tsk->user->uid_keyring;
+ key = context->user->uid_keyring;
atomic_inc(&key->usage);
break;
case KEY_SPEC_USER_SESSION_KEYRING:
- key = tsk->user->session_keyring;
+ key = context->user->session_keyring;
atomic_inc(&key->usage);
break;
@@ -574,7 +616,7 @@ struct key *lookup_user_key(key_serial_t id, int create, int partial,
break;
}
- /* check the status and permissions */
+ /* check the status */
if (perm) {
ret = key_validate(key);
if (ret < 0)
@@ -585,8 +627,10 @@ struct key *lookup_user_key(key_serial_t id, int create, int partial,
if (!partial && !test_bit(KEY_FLAG_INSTANTIATED, &key->flags))
goto invalid_key;
+ /* check the permissions */
ret = -EACCES;
- if (!key_permission(key, perm))
+
+ if (!key_task_permission(key, context, perm))
goto invalid_key;
error:
@@ -609,7 +653,6 @@ struct key *lookup_user_key(key_serial_t id, int create, int partial,
long join_session_keyring(const char *name)
{
struct task_struct *tsk = current;
- unsigned long flags;
struct key *keyring;
long ret;
@@ -619,9 +662,9 @@ long join_session_keyring(const char *name)
if (ret < 0)
goto error;
- spin_lock_irqsave(&tsk->sighand->siglock, flags);
- ret = tsk->signal->session_keyring->serial;
- spin_unlock_irqrestore(&tsk->sighand->siglock, flags);
+ rcu_read_lock();
+ ret = rcu_dereference(tsk->signal->session_keyring)->serial;
+ rcu_read_unlock();
goto error;
}
diff --git a/security/keys/request_key.c b/security/keys/request_key.c
index 54aa7b70e63..dfcd983af1f 100644
--- a/security/keys/request_key.c
+++ b/security/keys/request_key.c
@@ -1,6 +1,6 @@
/* request_key.c: request a key from userspace
*
- * Copyright (C) 2004 Red Hat, Inc. All Rights Reserved.
+ * Copyright (C) 2004-5 Red Hat, Inc. All Rights Reserved.
* Written by David Howells (dhowells@redhat.com)
*
* This program is free software; you can redistribute it and/or
@@ -13,6 +13,7 @@
#include <linux/sched.h>
#include <linux/kmod.h>
#include <linux/err.h>
+#include <linux/keyctl.h>
#include "internal.h"
struct key_construction {
@@ -27,18 +28,26 @@ DECLARE_WAIT_QUEUE_HEAD(request_key_conswq);
/*
* request userspace finish the construction of a key
* - execute "/sbin/request-key <op> <key> <uid> <gid> <keyring> <keyring> <keyring> <info>"
- * - if callout_info is an empty string, it'll be rendered as a "-" instead
*/
static int call_request_key(struct key *key,
const char *op,
const char *callout_info)
{
struct task_struct *tsk = current;
- unsigned long flags;
key_serial_t prkey, sskey;
+ struct key *session_keyring, *rkakey;
char *argv[10], *envp[3], uid_str[12], gid_str[12];
char key_str[12], keyring_str[3][12];
- int i;
+ int ret, i;
+
+ kenter("{%d},%s,%s", key->serial, op, callout_info);
+
+ /* generate a new session keyring with an auth key in it */
+ session_keyring = request_key_auth_new(key, &rkakey);
+ if (IS_ERR(session_keyring)) {
+ ret = PTR_ERR(session_keyring);
+ goto error;
+ }
/* record the UID and GID */
sprintf(uid_str, "%d", current->fsuid);
@@ -55,17 +64,17 @@ static int call_request_key(struct key *key,
if (tsk->signal->process_keyring)
prkey = tsk->signal->process_keyring->serial;
- sskey = 0;
- spin_lock_irqsave(&tsk->sighand->siglock, flags);
- if (tsk->signal->session_keyring)
- sskey = tsk->signal->session_keyring->serial;
- spin_unlock_irqrestore(&tsk->sighand->siglock, flags);
-
+ sprintf(keyring_str[1], "%d", prkey);
- if (!sskey)
+ if (tsk->signal->session_keyring) {
+ rcu_read_lock();
+ sskey = rcu_dereference(tsk->signal->session_keyring)->serial;
+ rcu_read_unlock();
+ }
+ else {
sskey = tsk->user->session_keyring->serial;
+ }
- sprintf(keyring_str[1], "%d", prkey);
sprintf(keyring_str[2], "%d", sskey);
/* set up a minimal environment */
@@ -84,11 +93,20 @@ static int call_request_key(struct key *key,
argv[i++] = keyring_str[0];
argv[i++] = keyring_str[1];
argv[i++] = keyring_str[2];
- argv[i++] = callout_info[0] ? (char *) callout_info : "-";
+ argv[i++] = (char *) callout_info;
argv[i] = NULL;
/* do it */
- return call_usermodehelper_keys(argv[0], argv, envp, NULL, 1);
+ ret = call_usermodehelper_keys(argv[0], argv, envp, session_keyring, 1);
+
+ /* dispose of the special keys */
+ key_revoke(rkakey);
+ key_put(rkakey);
+ key_put(session_keyring);
+
+ error:
+ kleave(" = %d", ret);
+ return ret;
} /* end call_request_key() */
@@ -107,6 +125,8 @@ static struct key *__request_key_construction(struct key_type *type,
struct key *key;
int ret, negated;
+ kenter("%s,%s,%s", type->name, description, callout_info);
+
/* create a key and add it to the queue */
key = key_alloc(type, description,
current->fsuid, current->fsgid, KEY_USR_ALL, 0);
@@ -143,6 +163,7 @@ static struct key *__request_key_construction(struct key_type *type,
}
out:
+ kleave(" = %p", key);
return key;
request_failed:
@@ -216,6 +237,9 @@ static struct key *request_key_construction(struct key_type *type,
DECLARE_WAITQUEUE(myself, current);
+ kenter("%s,%s,{%d},%s",
+ type->name, description, user->uid, callout_info);
+
/* see if there's such a key under construction already */
down_write(&key_construction_sem);
@@ -232,6 +256,7 @@ static struct key *request_key_construction(struct key_type *type,
/* see about getting userspace to construct the key */
key = __request_key_construction(type, description, callout_info);
error:
+ kleave(" = %p", key);
return key;
/* someone else has the same key under construction
@@ -245,9 +270,11 @@ static struct key *request_key_construction(struct key_type *type,
add_wait_queue(&request_key_conswq, &myself);
for (;;) {
- set_current_state(TASK_UNINTERRUPTIBLE);
+ set_current_state(TASK_INTERRUPTIBLE);
if (!test_bit(KEY_FLAG_USER_CONSTRUCT, &ckey->flags))
break;
+ if (signal_pending(current))
+ break;
schedule();
}
@@ -267,21 +294,83 @@ static struct key *request_key_construction(struct key_type *type,
/*****************************************************************************/
/*
+ * link a freshly minted key to an appropriate destination keyring
+ */
+static void request_key_link(struct key *key, struct key *dest_keyring)
+{
+ struct task_struct *tsk = current;
+ struct key *drop = NULL;
+
+ kenter("{%d},%p", key->serial, dest_keyring);
+
+ /* find the appropriate keyring */
+ if (!dest_keyring) {
+ switch (tsk->jit_keyring) {
+ case KEY_REQKEY_DEFL_DEFAULT:
+ case KEY_REQKEY_DEFL_THREAD_KEYRING:
+ dest_keyring = tsk->thread_keyring;
+ if (dest_keyring)
+ break;
+
+ case KEY_REQKEY_DEFL_PROCESS_KEYRING:
+ dest_keyring = tsk->signal->process_keyring;
+ if (dest_keyring)
+ break;
+
+ case KEY_REQKEY_DEFL_SESSION_KEYRING:
+ rcu_read_lock();
+ dest_keyring = key_get(
+ rcu_dereference(tsk->signal->session_keyring));
+ rcu_read_unlock();
+ drop = dest_keyring;
+
+ if (dest_keyring)
+ break;
+
+ case KEY_REQKEY_DEFL_USER_SESSION_KEYRING:
+ dest_keyring = current->user->session_keyring;
+ break;
+
+ case KEY_REQKEY_DEFL_USER_KEYRING:
+ dest_keyring = current->user->uid_keyring;
+ break;
+
+ case KEY_REQKEY_DEFL_GROUP_KEYRING:
+ default:
+ BUG();
+ }
+ }
+
+ /* and attach the key to it */
+ key_link(dest_keyring, key);
+
+ key_put(drop);
+
+ kleave("");
+
+} /* end request_key_link() */
+
+/*****************************************************************************/
+/*
* request a key
* - search the process's keyrings
* - check the list of keys being created or updated
- * - call out to userspace for a key if requested (supplementary info can be
- * passed)
+ * - call out to userspace for a key if supplementary info was provided
+ * - cache the key in an appropriate keyring
*/
-struct key *request_key(struct key_type *type,
- const char *description,
- const char *callout_info)
+struct key *request_key_and_link(struct key_type *type,
+ const char *description,
+ const char *callout_info,
+ struct key *dest_keyring)
{
struct key_user *user;
struct key *key;
+ kenter("%s,%s,%s,%p",
+ type->name, description, callout_info, dest_keyring);
+
/* search all the process keyrings for a key */
- key = search_process_keyrings_aux(type, description, type->match);
+ key = search_process_keyrings(type, description, type->match, current);
if (PTR_ERR(key) == -EAGAIN) {
/* the search failed, but the keyrings were searchable, so we
@@ -292,12 +381,13 @@ struct key *request_key(struct key_type *type,
/* - get hold of the user's construction queue */
user = key_user_lookup(current->fsuid);
- if (!user) {
- key = ERR_PTR(-ENOMEM);
- goto error;
- }
+ if (!user)
+ goto nomem;
+
+ do {
+ if (signal_pending(current))
+ goto interrupted;
- for (;;) {
/* ask userspace (returns NULL if it waited on a key
* being constructed) */
key = request_key_construction(type, description,
@@ -307,18 +397,46 @@ struct key *request_key(struct key_type *type,
/* someone else made the key we want, so we need to
* search again as it might now be available to us */
- key = search_process_keyrings_aux(type, description,
- type->match);
- if (PTR_ERR(key) != -EAGAIN)
- break;
- }
+ key = search_process_keyrings(type, description,
+ type->match, current);
+
+ } while (PTR_ERR(key) == -EAGAIN);
key_user_put(user);
+
+ /* link the new key into the appropriate keyring */
+ if (!PTR_ERR(key))
+ request_key_link(key, dest_keyring);
}
- error:
+error:
+ kleave(" = %p", key);
return key;
+nomem:
+ key = ERR_PTR(-ENOMEM);
+ goto error;
+
+interrupted:
+ key_user_put(user);
+ key = ERR_PTR(-EINTR);
+ goto error;
+
+} /* end request_key_and_link() */
+
+/*****************************************************************************/
+/*
+ * request a key
+ * - search the process's keyrings
+ * - check the list of keys being created or updated
+ * - call out to userspace for a key if supplementary info was provided
+ */
+struct key *request_key(struct key_type *type,
+ const char *description,
+ const char *callout_info)
+{
+ return request_key_and_link(type, description, callout_info, NULL);
+
} /* end request_key() */
EXPORT_SYMBOL(request_key);
diff --git a/security/keys/request_key_auth.c b/security/keys/request_key_auth.c
new file mode 100644
index 00000000000..f2226463222
--- /dev/null
+++ b/security/keys/request_key_auth.c
@@ -0,0 +1,180 @@
+/* request_key_auth.c: request key authorisation controlling key def
+ *
+ * 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 <linux/sched.h>
+#include <linux/err.h>
+#include <linux/seq_file.h>
+#include "internal.h"
+
+static int request_key_auth_instantiate(struct key *, const void *, size_t);
+static void request_key_auth_describe(const struct key *, struct seq_file *);
+static void request_key_auth_destroy(struct key *);
+
+/*
+ * the request-key authorisation key type definition
+ */
+struct key_type key_type_request_key_auth = {
+ .name = ".request_key_auth",
+ .def_datalen = sizeof(struct request_key_auth),
+ .instantiate = request_key_auth_instantiate,
+ .describe = request_key_auth_describe,
+ .destroy = request_key_auth_destroy,
+};
+
+/*****************************************************************************/
+/*
+ * instantiate a request-key authorisation record
+ */
+static int request_key_auth_instantiate(struct key *key,
+ const void *data,
+ size_t datalen)
+{
+ struct request_key_auth *rka, *irka;
+ struct key *instkey;
+ int ret;
+
+ ret = -ENOMEM;
+ rka = kmalloc(sizeof(*rka), GFP_KERNEL);
+ if (rka) {
+ /* see if the calling process is already servicing the key
+ * request of another process */
+ instkey = key_get_instantiation_authkey(0);
+ if (!IS_ERR(instkey)) {
+ /* it is - use that instantiation context here too */
+ irka = instkey->payload.data;
+ rka->context = irka->context;
+ rka->pid = irka->pid;
+ key_put(instkey);
+ }
+ else {
+ /* it isn't - use this process as the context */
+ rka->context = current;
+ rka->pid = current->pid;
+ }
+
+ rka->target_key = key_get((struct key *) data);
+ key->payload.data = rka;
+ ret = 0;
+ }
+
+ return ret;
+
+} /* end request_key_auth_instantiate() */
+
+/*****************************************************************************/
+/*
+ *
+ */
+static void request_key_auth_describe(const struct key *key,
+ struct seq_file *m)
+{
+ struct request_key_auth *rka = key->payload.data;
+
+ seq_puts(m, "key:");
+ seq_puts(m, key->description);
+ seq_printf(m, " pid:%d", rka->pid);
+
+} /* end request_key_auth_describe() */
+
+/*****************************************************************************/
+/*
+ * destroy an instantiation authorisation token key
+ */
+static void request_key_auth_destroy(struct key *key)
+{
+ struct request_key_auth *rka = key->payload.data;
+
+ kenter("{%d}", key->serial);
+
+ key_put(rka->target_key);
+
+} /* end request_key_auth_destroy() */
+
+/*****************************************************************************/
+/*
+ * create a session keyring to be for the invokation of /sbin/request-key and
+ * stick an authorisation token in it
+ */
+struct key *request_key_auth_new(struct key *target, struct key **_rkakey)
+{
+ struct key *keyring, *rkakey = NULL;
+ char desc[20];
+ int ret;
+
+ kenter("%d,", target->serial);
+
+ /* allocate a new session keyring */
+ sprintf(desc, "_req.%u", target->serial);
+
+ keyring = keyring_alloc(desc, current->fsuid, current->fsgid, 1, NULL);
+ if (IS_ERR(keyring)) {
+ kleave("= %ld", PTR_ERR(keyring));
+ return keyring;
+ }
+
+ /* allocate the auth key */
+ sprintf(desc, "%x", target->serial);
+
+ rkakey = key_alloc(&key_type_request_key_auth, desc,
+ current->fsuid, current->fsgid,
+ KEY_USR_VIEW, 1);
+ if (IS_ERR(rkakey)) {
+ key_put(keyring);
+ kleave("= %ld", PTR_ERR(rkakey));
+ return rkakey;
+ }
+
+ /* construct and attach to the keyring */
+ ret = key_instantiate_and_link(rkakey, target, 0, keyring, NULL);
+ if (ret < 0) {
+ key_revoke(rkakey);
+ key_put(rkakey);
+ key_put(keyring);
+ kleave("= %d", ret);
+ return ERR_PTR(ret);
+ }
+
+ *_rkakey = rkakey;
+ kleave(" = {%d} ({%d})", keyring->serial, rkakey->serial);
+ return keyring;
+
+} /* end request_key_auth_new() */
+
+/*****************************************************************************/
+/*
+ * get the authorisation key for instantiation of a specific key if attached to
+ * the current process's keyrings
+ * - this key is inserted into a keyring and that is set as /sbin/request-key's
+ * session keyring
+ * - a target_id of zero specifies any valid token
+ */
+struct key *key_get_instantiation_authkey(key_serial_t target_id)
+{
+ struct task_struct *tsk = current;
+ struct key *instkey;
+
+ /* we must have our own personal session keyring */
+ if (!tsk->signal->session_keyring)
+ return ERR_PTR(-EACCES);
+
+ /* and it must contain a suitable request authorisation key
+ * - lock RCU against session keyring changing
+ */
+ rcu_read_lock();
+
+ instkey = keyring_search_instkey(
+ rcu_dereference(tsk->signal->session_keyring), target_id);
+
+ rcu_read_unlock();
+ return instkey;
+
+} /* end key_get_instantiation_authkey() */