[mirror_ubuntu-artful-kernel.git] / include / linux / key.h

/* Authentication token and access key management
 *
 * Copyright (C) 2004, 2007 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.
 *
 *
 * See Documentation/security/keys.txt for information on keys/keyrings.
 */

#ifndef _LINUX_KEY_H
#define _LINUX_KEY_H

#include <linux/types.h>
#include <linux/list.h>
#include <linux/rbtree.h>
#include <linux/rcupdate.h>
#include <linux/sysctl.h>
#include <linux/rwsem.h>
#include <linux/atomic.h>
#include <linux/assoc_array.h>

#ifdef __KERNEL__
#include <linux/uidgid.h>

/* key handle serial number */
typedef int32_t key_serial_t;

/* key handle permissions mask */
typedef uint32_t key_perm_t;

struct key;

#ifdef CONFIG_KEYS

#undef KEY_DEBUGGING

#define KEY_POS_VIEW	0x01000000	/* possessor can view a key's attributes */
#define KEY_POS_READ	0x02000000	/* possessor can read key payload / view keyring */
#define KEY_POS_WRITE	0x04000000	/* possessor can update key payload / add link to keyring */
#define KEY_POS_SEARCH	0x08000000	/* possessor can find a key in search / search a keyring */
#define KEY_POS_LINK	0x10000000	/* possessor can create a link to a key/keyring */
#define KEY_POS_SETATTR	0x20000000	/* possessor can set key attributes */
#define KEY_POS_ALL	0x3f000000

#define KEY_USR_VIEW	0x00010000	/* user permissions... */
#define KEY_USR_READ	0x00020000
#define KEY_USR_WRITE	0x00040000
#define KEY_USR_SEARCH	0x00080000
#define KEY_USR_LINK	0x00100000
#define KEY_USR_SETATTR	0x00200000
#define KEY_USR_ALL	0x003f0000

#define KEY_GRP_VIEW	0x00000100	/* group permissions... */
#define KEY_GRP_READ	0x00000200
#define KEY_GRP_WRITE	0x00000400
#define KEY_GRP_SEARCH	0x00000800
#define KEY_GRP_LINK	0x00001000
#define KEY_GRP_SETATTR	0x00002000
#define KEY_GRP_ALL	0x00003f00

#define KEY_OTH_VIEW	0x00000001	/* third party permissions... */
#define KEY_OTH_READ	0x00000002
#define KEY_OTH_WRITE	0x00000004
#define KEY_OTH_SEARCH	0x00000008
#define KEY_OTH_LINK	0x00000010
#define KEY_OTH_SETATTR	0x00000020
#define KEY_OTH_ALL	0x0000003f

#define KEY_PERM_UNDEF	0xffffffff

struct seq_file;
struct user_struct;
struct signal_struct;
struct cred;

struct key_type;
struct key_owner;
struct keyring_list;
struct keyring_name;

struct keyring_index_key {
	struct key_type		*type;
	const char		*description;
	size_t			desc_len;
};

union key_payload {
	void __rcu		*rcu_data0;
	void			*data[4];
};

/*****************************************************************************/
/*
 * key reference with possession attribute handling
 *
 * NOTE! key_ref_t is a typedef'd pointer to a type that is not actually
 * defined. This is because we abuse the bottom bit of the reference to carry a
 * flag to indicate whether the calling process possesses that key in one of
 * its keyrings.
 *
 * the key_ref_t has been made a separate type so that the compiler can reject
 * attempts to dereference it without proper conversion.
 *
 * the three functions are used to assemble and disassemble references
 */
typedef struct __key_reference_with_attributes *key_ref_t;

static inline key_ref_t make_key_ref(const struct key *key,
				     bool possession)
{
	return (key_ref_t) ((unsigned long) key | possession);
}

static inline struct key *key_ref_to_ptr(const key_ref_t key_ref)
{
	return (struct key *) ((unsigned long) key_ref & ~1UL);
}

static inline bool is_key_possessed(const key_ref_t key_ref)
{
	return (unsigned long) key_ref & 1UL;
}

/*****************************************************************************/
/*
 * authentication token / access credential / keyring
 * - types of key include:
 *   - keyrings
 *   - disk encryption IDs
 *   - Kerberos TGTs and tickets
 */
struct key {
	atomic_t		usage;		/* number of references */
	key_serial_t		serial;		/* key serial number */
	union {
		struct list_head graveyard_link;
		struct rb_node	serial_node;
	};
	struct rw_semaphore	sem;		/* change vs change sem */
	struct key_user		*user;		/* owner of this key */
	void			*security;	/* security data for this key */
	union {
		time_t		expiry;		/* time at which key expires (or 0) */
		time_t		revoked_at;	/* time at which key was revoked */
	};
	time_t			last_used_at;	/* last time used for LRU keyring discard */
	kuid_t			uid;
	kgid_t			gid;
	key_perm_t		perm;		/* access permissions */
	unsigned short		quotalen;	/* length added to quota */
	unsigned short		datalen;	/* payload data length
						 * - may not match RCU dereferenced payload
						 * - payload should contain own length
						 */

#ifdef KEY_DEBUGGING
	unsigned		magic;
#define KEY_DEBUG_MAGIC		0x18273645u
#define KEY_DEBUG_MAGIC_X	0xf8e9dacbu
#endif

	unsigned long		flags;		/* status flags (change with bitops) */
#define KEY_FLAG_INSTANTIATED	0	/* set if key has been instantiated */
#define KEY_FLAG_DEAD		1	/* set if key type has been deleted */
#define KEY_FLAG_REVOKED	2	/* set if key had been revoked */
#define KEY_FLAG_IN_QUOTA	3	/* set if key consumes quota */
#define KEY_FLAG_USER_CONSTRUCT	4	/* set if key is being constructed in userspace */
#define KEY_FLAG_NEGATIVE	5	/* set if key is negative */
#define KEY_FLAG_ROOT_CAN_CLEAR	6	/* set if key can be cleared by root without permission */
#define KEY_FLAG_INVALIDATED	7	/* set if key has been invalidated */
#define KEY_FLAG_BUILTIN	8	/* set if key is built in to the kernel */
#define KEY_FLAG_ROOT_CAN_INVAL	9	/* set if key can be invalidated by root without permission */
#define KEY_FLAG_KEEP		10	/* set if key should not be removed */

	/* the key type and key description string
	 * - the desc is used to match a key against search criteria
	 * - it should be a printable string
	 * - eg: for krb5 AFS, this might be "afs@REDHAT.COM"
	 */
	union {
		struct keyring_index_key index_key;
		struct {
			struct key_type	*type;		/* type of key */
			char		*description;
		};
	};

	/* key data
	 * - this is used to hold the data actually used in cryptography or
	 *   whatever
	 */
	union {
		union key_payload payload;
		struct {
			/* Keyring bits */
			struct list_head name_link;
			struct assoc_array keys;
		};
		int reject_error;
	};

	/* This is set on a keyring to restrict the addition of a link to a key
	 * to it.  If this method isn't provided then it is assumed that the
	 * keyring is open to any addition.  It is ignored for non-keyring
	 * keys.
	 *
	 * This is intended for use with rings of trusted keys whereby addition
	 * to the keyring needs to be controlled.  KEY_ALLOC_BYPASS_RESTRICTION
	 * overrides this, allowing the kernel to add extra keys without
	 * restriction.
	 */
	int (*restrict_link)(struct key *keyring,
			     const struct key_type *type,
			     const union key_payload *payload);
};

extern struct key *key_alloc(struct key_type *type,
			     const char *desc,
			     kuid_t uid, kgid_t gid,
			     const struct cred *cred,
			     key_perm_t perm,
			     unsigned long flags,
			     int (*restrict_link)(struct key *,
						  const struct key_type *,
						  const union key_payload *));


#define KEY_ALLOC_IN_QUOTA		0x0000	/* add to quota, reject if would overrun */
#define KEY_ALLOC_QUOTA_OVERRUN		0x0001	/* add to quota, permit even if overrun */
#define KEY_ALLOC_NOT_IN_QUOTA		0x0002	/* not in quota */
#define KEY_ALLOC_BUILT_IN		0x0004	/* Key is built into kernel */
#define KEY_ALLOC_BYPASS_RESTRICTION	0x0008	/* Override the check on restricted keyrings */

extern void key_revoke(struct key *key);
extern void key_invalidate(struct key *key);
extern void key_put(struct key *key);

static inline struct key *__key_get(struct key *key)
{
	atomic_inc(&key->usage);
	return key;
}

static inline struct key *key_get(struct key *key)
{
	return key ? __key_get(key) : key;
}

static inline void key_ref_put(key_ref_t key_ref)
{
	key_put(key_ref_to_ptr(key_ref));
}

extern struct key *request_key(struct key_type *type,
			       const char *description,
			       const char *callout_info);

extern struct key *request_key_with_auxdata(struct key_type *type,
					    const char *description,
					    const void *callout_info,
					    size_t callout_len,
					    void *aux);

extern struct key *request_key_async(struct key_type *type,
				     const char *description,
				     const void *callout_info,
				     size_t callout_len);

extern struct key *request_key_async_with_auxdata(struct key_type *type,
						  const char *description,
						  const void *callout_info,
						  size_t callout_len,
						  void *aux);

extern int wait_for_key_construction(struct key *key, bool intr);

extern int key_validate(const struct key *key);

extern key_ref_t key_create_or_update(key_ref_t keyring,
				      const char *type,
				      const char *description,
				      const void *payload,
				      size_t plen,
				      key_perm_t perm,
				      unsigned long flags);

extern int key_update(key_ref_t key,
		      const void *payload,
		      size_t plen);

extern int key_link(struct key *keyring,
		    struct key *key);

extern int key_unlink(struct key *keyring,
		      struct key *key);

extern struct key *keyring_alloc(const char *description, kuid_t uid, kgid_t gid,
				 const struct cred *cred,
				 key_perm_t perm,
				 unsigned long flags,
				 int (*restrict_link)(struct key *,
						      const struct key_type *,
						      const union key_payload *),
				 struct key *dest);

extern int restrict_link_reject(struct key *keyring,
				const struct key_type *type,
				const union key_payload *payload);

extern int keyring_clear(struct key *keyring);

extern key_ref_t keyring_search(key_ref_t keyring,
				struct key_type *type,
				const char *description);

extern int keyring_add_key(struct key *keyring,
			   struct key *key);

extern struct key *key_lookup(key_serial_t id);

static inline key_serial_t key_serial(const struct key *key)
{
	return key ? key->serial : 0;
}

extern void key_set_timeout(struct key *, unsigned);

/*
 * The permissions required on a key that we're looking up.
 */
#define	KEY_NEED_VIEW	0x01	/* Require permission to view attributes */
#define	KEY_NEED_READ	0x02	/* Require permission to read content */
#define	KEY_NEED_WRITE	0x04	/* Require permission to update / modify */
#define	KEY_NEED_SEARCH	0x08	/* Require permission to search (keyring) or find (key) */
#define	KEY_NEED_LINK	0x10	/* Require permission to link */
#define	KEY_NEED_SETATTR 0x20	/* Require permission to change attributes */
#define	KEY_NEED_ALL	0x3f	/* All the above permissions */

/**
 * key_is_instantiated - Determine if a key has been positively instantiated
 * @key: The key to check.
 *
 * Return true if the specified key has been positively instantiated, false
 * otherwise.
 */
static inline bool key_is_instantiated(const struct key *key)
{
	return test_bit(KEY_FLAG_INSTANTIATED, &key->flags) &&
		!test_bit(KEY_FLAG_NEGATIVE, &key->flags);
}

#define dereference_key_rcu(KEY)					\
	(rcu_dereference((KEY)->payload.rcu_data0))

#define dereference_key_locked(KEY)					\
	(rcu_dereference_protected((KEY)->payload.rcu_data0,		\
				   rwsem_is_locked(&((struct key *)(KEY))->sem)))

#define rcu_assign_keypointer(KEY, PAYLOAD)				\
do {									\
	rcu_assign_pointer((KEY)->payload.rcu_data0, (PAYLOAD));	\
} while (0)

#ifdef CONFIG_SYSCTL
extern struct ctl_table key_sysctls[];
#endif
/*
 * the userspace interface
 */
extern int install_thread_keyring_to_cred(struct cred *cred);
extern void key_fsuid_changed(struct task_struct *tsk);
extern void key_fsgid_changed(struct task_struct *tsk);
extern void key_init(void);

#else /* CONFIG_KEYS */

#define key_validate(k)			0
#define key_serial(k)			0
#define key_get(k) 			({ NULL; })
#define key_revoke(k)			do { } while(0)
#define key_invalidate(k)		do { } while(0)
#define key_put(k)			do { } while(0)
#define key_ref_put(k)			do { } while(0)
#define make_key_ref(k, p)		NULL
#define key_ref_to_ptr(k)		NULL
#define is_key_possessed(k)		0
#define key_fsuid_changed(t)		do { } while(0)
#define key_fsgid_changed(t)		do { } while(0)
#define key_init()			do { } while(0)

#endif /* CONFIG_KEYS */
#endif /* __KERNEL__ */
#endif /* _LINUX_KEY_H */
Commit	Line	Data
76181c13	1	/* Authentication token and access key management
1da177e4	2	*
76181c13	3	* Copyright (C) 2004, 2007 Red Hat, Inc. All Rights Reserved.
1da177e4 LT	4	* Written by David Howells (dhowells@redhat.com)
	5	*
	6	* This program is free software; you can redistribute it and/or
	7	* modify it under the terms of the GNU General Public License
	8	* as published by the Free Software Foundation; either version
	9	* 2 of the License, or (at your option) any later version.
	10	*
	11	*
d410fa4e	12	* See Documentation/security/keys.txt for information on keys/keyrings.
1da177e4 LT	13	*/
	14
	15	#ifndef _LINUX_KEY_H
	16	#define _LINUX_KEY_H
	17
	18	#include <linux/types.h>
	19	#include <linux/list.h>
	20	#include <linux/rbtree.h>
76d8aeab	21	#include <linux/rcupdate.h>
0b77f5bf	22	#include <linux/sysctl.h>
aa84442d	23	#include <linux/rwsem.h>
60063497	24	#include <linux/atomic.h>
b2a4df20	25	#include <linux/assoc_array.h>
1da177e4 LT	26
1da177e4 LT	27	#ifdef __KERNEL__
9a56c2db	28	#include <linux/uidgid.h>
1da177e4 LT	29
	30	/* key handle serial number */
	31	typedef int32_t key_serial_t;
	32
	33	/* key handle permissions mask */
	34	typedef uint32_t key_perm_t;
	35
	36	struct key;
	37
	38	#ifdef CONFIG_KEYS
	39
	40	#undef KEY_DEBUGGING
	41
664cceb0 DH	42	#define KEY_POS_VIEW 0x01000000 /* possessor can view a key's attributes */
	43	#define KEY_POS_READ 0x02000000 /* possessor can read key payload / view keyring */
	44	#define KEY_POS_WRITE 0x04000000 /* possessor can update key payload / add link to keyring */
	45	#define KEY_POS_SEARCH 0x08000000 /* possessor can find a key in search / search a keyring */
	46	#define KEY_POS_LINK 0x10000000 /* possessor can create a link to a key/keyring */
29db9190 DH	47	#define KEY_POS_SETATTR 0x20000000 /* possessor can set key attributes */
29db9190 DH	48	#define KEY_POS_ALL 0x3f000000
664cceb0 DH	49
	50	#define KEY_USR_VIEW 0x00010000 /* user permissions... */
	51	#define KEY_USR_READ 0x00020000
	52	#define KEY_USR_WRITE 0x00040000
	53	#define KEY_USR_SEARCH 0x00080000
	54	#define KEY_USR_LINK 0x00100000
29db9190 DH	55	#define KEY_USR_SETATTR 0x00200000
29db9190 DH	56	#define KEY_USR_ALL 0x003f0000
1da177e4 LT	57
	58	#define KEY_GRP_VIEW 0x00000100 /* group permissions... */
	59	#define KEY_GRP_READ 0x00000200
	60	#define KEY_GRP_WRITE 0x00000400
	61	#define KEY_GRP_SEARCH 0x00000800
	62	#define KEY_GRP_LINK 0x00001000
29db9190 DH	63	#define KEY_GRP_SETATTR 0x00002000
29db9190 DH	64	#define KEY_GRP_ALL 0x00003f00
1da177e4 LT	65
	66	#define KEY_OTH_VIEW 0x00000001 /* third party permissions... */
	67	#define KEY_OTH_READ 0x00000002
	68	#define KEY_OTH_WRITE 0x00000004
	69	#define KEY_OTH_SEARCH 0x00000008
	70	#define KEY_OTH_LINK 0x00000010
29db9190 DH	71	#define KEY_OTH_SETATTR 0x00000020
29db9190 DH	72	#define KEY_OTH_ALL 0x0000003f
1da177e4	73
6b79ccb5 AR	74	#define KEY_PERM_UNDEF 0xffffffff
6b79ccb5 AR	75
1da177e4 LT	76	struct seq_file;
	77	struct user_struct;
	78	struct signal_struct;
d84f4f99	79	struct cred;
1da177e4 LT	80
	81	struct key_type;
	82	struct key_owner;
	83	struct keyring_list;
	84	struct keyring_name;
	85
16feef43 DH	86	struct keyring_index_key {
	87	struct key_type *type;
	88	const char *description;
	89	size_t desc_len;
	90	};
	91
146aa8b1 DH	92	union key_payload {
	93	void __rcu *rcu_data0;
	94	void *data[4];
	95	};
	96
664cceb0 DH	97	/*****************************************************************************/
	98	/*
	99	* key reference with possession attribute handling
	100	*
	101	* NOTE! key_ref_t is a typedef'd pointer to a type that is not actually
	102	* defined. This is because we abuse the bottom bit of the reference to carry a
	103	* flag to indicate whether the calling process possesses that key in one of
	104	* its keyrings.
	105	*
	106	* the key_ref_t has been made a separate type so that the compiler can reject
	107	* attempts to dereference it without proper conversion.
	108	*
	109	* the three functions are used to assemble and disassemble references
	110	*/
	111	typedef struct __key_reference_with_attributes *key_ref_t;
	112
	113	static inline key_ref_t make_key_ref(const struct key *key,
a5b4bd28	114	bool possession)
664cceb0 DH	115	{
	116	return (key_ref_t) ((unsigned long) key \| possession);
	117	}
	118
	119	static inline struct key *key_ref_to_ptr(const key_ref_t key_ref)
	120	{
	121	return (struct key *) ((unsigned long) key_ref & ~1UL);
	122	}
	123
a5b4bd28	124	static inline bool is_key_possessed(const key_ref_t key_ref)
664cceb0 DH	125	{
	126	return (unsigned long) key_ref & 1UL;
	127	}
	128
1da177e4 LT	129	/*****************************************************************************/
	130	/*
	131	* authentication token / access credential / keyring
	132	* - types of key include:
	133	* - keyrings
	134	* - disk encryption IDs
	135	* - Kerberos TGTs and tickets
	136	*/
	137	struct key {
	138	atomic_t usage; /* number of references */
	139	key_serial_t serial; /* key serial number */
65d87fe6 DH	140	union {
	141	struct list_head graveyard_link;
	142	struct rb_node serial_node;
	143	};
1da177e4 LT	144	struct rw_semaphore sem; /* change vs change sem */
1da177e4 LT	145	struct key_user user; / owner of this key */
29db9190	146	void security; / security data for this key */
5d135440 DH	147	union {
	148	time_t expiry; /* time at which key expires (or 0) */
	149	time_t revoked_at; /* time at which key was revoked */
	150	};
31d5a79d	151	time_t last_used_at; /* last time used for LRU keyring discard */
9a56c2db EB	152	kuid_t uid;
9a56c2db EB	153	kgid_t gid;
1da177e4 LT	154	key_perm_t perm; /* access permissions */
1da177e4 LT	155	unsigned short quotalen; /* length added to quota */
76d8aeab DH	156	unsigned short datalen; /* payload data length
	157	* - may not match RCU dereferenced payload
	158	* - payload should contain own length
	159	*/
1da177e4 LT	160
	161	#ifdef KEY_DEBUGGING
	162	unsigned magic;
	163	#define KEY_DEBUG_MAGIC 0x18273645u
	164	#define KEY_DEBUG_MAGIC_X 0xf8e9dacbu
	165	#endif
	166
76d8aeab DH	167	unsigned long flags; /* status flags (change with bitops) */
	168	#define KEY_FLAG_INSTANTIATED 0 /* set if key has been instantiated */
	169	#define KEY_FLAG_DEAD 1 /* set if key type has been deleted */
	170	#define KEY_FLAG_REVOKED 2 /* set if key had been revoked */
	171	#define KEY_FLAG_IN_QUOTA 3 /* set if key consumes quota */
	172	#define KEY_FLAG_USER_CONSTRUCT 4 /* set if key is being constructed in userspace */
	173	#define KEY_FLAG_NEGATIVE 5 /* set if key is negative */
700920eb	174	#define KEY_FLAG_ROOT_CAN_CLEAR 6 /* set if key can be cleared by root without permission */
fd75815f	175	#define KEY_FLAG_INVALIDATED 7 /* set if key has been invalidated */
77f68bac DH	176	#define KEY_FLAG_BUILTIN 8 /* set if key is built in to the kernel */
	177	#define KEY_FLAG_ROOT_CAN_INVAL 9 /* set if key can be invalidated by root without permission */
	178	#define KEY_FLAG_KEEP 10 /* set if key should not be removed */
76d8aeab	179
16feef43 DH	180	/* the key type and key description string
	181	* - the desc is used to match a key against search criteria
	182	* - it should be a printable string
1da177e4 LT	183	* - eg: for krb5 AFS, this might be "afs@REDHAT.COM"
1da177e4 LT	184	*/
16feef43 DH	185	union {
	186	struct keyring_index_key index_key;
	187	struct {
	188	struct key_type type; / type of key */
	189	char *description;
	190	};
	191	};
1da177e4	192
1da177e4 LT	193	/* key data
	194	* - this is used to hold the data actually used in cryptography or
	195	* whatever
	196	*/
	197	union {
146aa8b1 DH	198	union key_payload payload;
	199	struct {
	200	/* Keyring bits */
	201	struct list_head name_link;
	202	struct assoc_array keys;
	203	};
	204	int reject_error;
b2a4df20	205	};
5ac7eace DH	206
	207	/* This is set on a keyring to restrict the addition of a link to a key
	208	* to it. If this method isn't provided then it is assumed that the
	209	* keyring is open to any addition. It is ignored for non-keyring
	210	* keys.
	211	*
	212	* This is intended for use with rings of trusted keys whereby addition
	213	* to the keyring needs to be controlled. KEY_ALLOC_BYPASS_RESTRICTION
	214	* overrides this, allowing the kernel to add extra keys without
	215	* restriction.
	216	*/
	217	int (restrict_link)(struct key keyring,
	218	const struct key_type *type,
5ac7eace	219	const union key_payload *payload);
1da177e4 LT	220	};
1da177e4 LT	221
1da177e4 LT	222	extern struct key key_alloc(struct key_type type,
1da177e4 LT	223	const char *desc,
9a56c2db	224	kuid_t uid, kgid_t gid,
d84f4f99	225	const struct cred *cred,
7e047ef5	226	key_perm_t perm,
5ac7eace DH	227	unsigned long flags,
	228	int (restrict_link)(struct key ,
	229	const struct key_type *,
5ac7eace	230	const union key_payload *));
7e047ef5 DH	231
7e047ef5 DH	232
5ac7eace DH	233	#define KEY_ALLOC_IN_QUOTA 0x0000 /* add to quota, reject if would overrun */
	234	#define KEY_ALLOC_QUOTA_OVERRUN 0x0001 /* add to quota, permit even if overrun */
	235	#define KEY_ALLOC_NOT_IN_QUOTA 0x0002 /* not in quota */
77f68bac DH	236	#define KEY_ALLOC_BUILT_IN 0x0004 /* Key is built into kernel */
77f68bac DH	237	#define KEY_ALLOC_BYPASS_RESTRICTION 0x0008 /* Override the check on restricted keyrings */
7e047ef5	238
1da177e4	239	extern void key_revoke(struct key *key);
fd75815f	240	extern void key_invalidate(struct key *key);
1da177e4 LT	241	extern void key_put(struct key *key);
1da177e4 LT	242
ccc3e6d9	243	static inline struct key __key_get(struct key key)
1da177e4	244	{
ccc3e6d9	245	atomic_inc(&key->usage);
1da177e4 LT	246	return key;
	247	}
	248
ccc3e6d9 DH	249	static inline struct key key_get(struct key key)
	250	{
	251	return key ? __key_get(key) : key;
	252	}
	253
664cceb0 DH	254	static inline void key_ref_put(key_ref_t key_ref)
	255	{
	256	key_put(key_ref_to_ptr(key_ref));
	257	}
	258
1da177e4 LT	259	extern struct key request_key(struct key_type type,
	260	const char *description,
	261	const char *callout_info);
	262
4e54f085 DH	263	extern struct key request_key_with_auxdata(struct key_type type,
4e54f085 DH	264	const char *description,
4a38e122 DH	265	const void *callout_info,
4a38e122 DH	266	size_t callout_len,
4e54f085 DH	267	void *aux);
4e54f085 DH	268
76181c13 DH	269	extern struct key request_key_async(struct key_type type,
76181c13 DH	270	const char *description,
4a38e122 DH	271	const void *callout_info,
4a38e122 DH	272	size_t callout_len);
76181c13 DH	273
	274	extern struct key request_key_async_with_auxdata(struct key_type type,
	275	const char *description,
4a38e122 DH	276	const void *callout_info,
4a38e122 DH	277	size_t callout_len,
76181c13 DH	278	void *aux);
	279
	280	extern int wait_for_key_construction(struct key *key, bool intr);
	281
b404aef7	282	extern int key_validate(const struct key *key);
1da177e4	283
664cceb0 DH	284	extern key_ref_t key_create_or_update(key_ref_t keyring,
	285	const char *type,
	286	const char *description,
	287	const void *payload,
	288	size_t plen,
6b79ccb5	289	key_perm_t perm,
7e047ef5	290	unsigned long flags);
1da177e4	291
664cceb0	292	extern int key_update(key_ref_t key,
1da177e4 LT	293	const void *payload,
	294	size_t plen);
	295
	296	extern int key_link(struct key *keyring,
	297	struct key *key);
	298
	299	extern int key_unlink(struct key *keyring,
	300	struct key *key);
	301
9a56c2db	302	extern struct key keyring_alloc(const char description, kuid_t uid, kgid_t gid,
d84f4f99	303	const struct cred *cred,
96b5c8fe	304	key_perm_t perm,
7e047ef5	305	unsigned long flags,
5ac7eace DH	306	int (restrict_link)(struct key ,
5ac7eace DH	307	const struct key_type *,
5ac7eace	308	const union key_payload *),
d720024e	309	struct key *dest);
1da177e4	310
5ac7eace DH	311	extern int restrict_link_reject(struct key *keyring,
5ac7eace DH	312	const struct key_type *type,
5ac7eace DH	313	const union key_payload *payload);
5ac7eace DH	314
1da177e4 LT	315	extern int keyring_clear(struct key *keyring);
1da177e4 LT	316
664cceb0 DH	317	extern key_ref_t keyring_search(key_ref_t keyring,
	318	struct key_type *type,
	319	const char *description);
1da177e4	320
1da177e4 LT	321	extern int keyring_add_key(struct key *keyring,
	322	struct key *key);
	323
	324	extern struct key *key_lookup(key_serial_t id);
	325
456a8167	326	static inline key_serial_t key_serial(const struct key *key)
7249db2c DH	327	{
	328	return key ? key->serial : 0;
	329	}
1da177e4	330
59e6b9c1 BS	331	extern void key_set_timeout(struct key *, unsigned);
59e6b9c1 BS	332
f5895943 DH	333	/*
	334	* The permissions required on a key that we're looking up.
	335	*/
	336	#define KEY_NEED_VIEW 0x01 /* Require permission to view attributes */
	337	#define KEY_NEED_READ 0x02 /* Require permission to read content */
	338	#define KEY_NEED_WRITE 0x04 /* Require permission to update / modify */
	339	#define KEY_NEED_SEARCH 0x08 /* Require permission to search (keyring) or find (key) */
	340	#define KEY_NEED_LINK 0x10 /* Require permission to link */
	341	#define KEY_NEED_SETATTR 0x20 /* Require permission to change attributes */
	342	#define KEY_NEED_ALL 0x3f /* All the above permissions */
	343
78b7280c DH	344	/**
	345	* key_is_instantiated - Determine if a key has been positively instantiated
	346	* @key: The key to check.
	347	*
	348	* Return true if the specified key has been positively instantiated, false
	349	* otherwise.
	350	*/
	351	static inline bool key_is_instantiated(const struct key *key)
	352	{
	353	return test_bit(KEY_FLAG_INSTANTIATED, &key->flags) &&
	354	!test_bit(KEY_FLAG_NEGATIVE, &key->flags);
	355	}
	356
0837e49a DH	357	#define dereference_key_rcu(KEY) \
	358	(rcu_dereference((KEY)->payload.rcu_data0))
	359
	360	#define dereference_key_locked(KEY) \
146aa8b1	361	(rcu_dereference_protected((KEY)->payload.rcu_data0, \
633e804e DH	362	rwsem_is_locked(&((struct key *)(KEY))->sem)))
633e804e DH	363
ee0b31a2	364	#define rcu_assign_keypointer(KEY, PAYLOAD) \
e5c1f444	365	do { \
146aa8b1	366	rcu_assign_pointer((KEY)->payload.rcu_data0, (PAYLOAD)); \
e5c1f444	367	} while (0)
ee0b31a2	368
0b77f5bf	369	#ifdef CONFIG_SYSCTL
d6f50c95	370	extern struct ctl_table key_sysctls[];
0b77f5bf	371	#endif
1da177e4 LT	372	/*
	373	* the userspace interface
	374	*/
d84f4f99	375	extern int install_thread_keyring_to_cred(struct cred *cred);
1da177e4 LT	376	extern void key_fsuid_changed(struct task_struct *tsk);
	377	extern void key_fsgid_changed(struct task_struct *tsk);
	378	extern void key_init(void);
	379
	380	#else /* CONFIG_KEYS */
	381
	382	#define key_validate(k) 0
	383	#define key_serial(k) 0
7888e7ff	384	#define key_get(k) ({ NULL; })
0dab9cfa	385	#define key_revoke(k) do { } while(0)
fd75815f	386	#define key_invalidate(k) do { } while(0)
1da177e4	387	#define key_put(k) do { } while(0)
664cceb0	388	#define key_ref_put(k) do { } while(0)
8bbf4976 DH	389	#define make_key_ref(k, p) NULL
8bbf4976 DH	390	#define key_ref_to_ptr(k) NULL
664cceb0	391	#define is_key_possessed(k) 0
1da177e4 LT	392	#define key_fsuid_changed(t) do { } while(0)
	393	#define key_fsgid_changed(t) do { } while(0)
	394	#define key_init() do { } while(0)
	395
	396	#endif /* CONFIG_KEYS */
	397	#endif /* __KERNEL__ */
	398	#endif /* _LINUX_KEY_H */