[linux-2.6-block.git] / include / linux / key.h

/* SPDX-License-Identifier: GPL-2.0-or-later */
/* Authentication token and access key management
 *
 * Copyright (C) 2004, 2007 Red Hat, Inc. All Rights Reserved.
 * Written by David Howells (dhowells@redhat.com)
 *
 * See Documentation/security/keys/core.rst 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>
#include <linux/refcount.h>
#include <linux/time64.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;
}

typedef int (*key_restrict_link_func_t)(struct key *dest_keyring,
					const struct key_type *type,
					const union key_payload *payload,
					struct key *restriction_key);

struct key_restriction {
	key_restrict_link_func_t check;
	struct key *key;
	struct key_type *keytype;
};

enum key_state {
	KEY_IS_UNINSTANTIATED,
	KEY_IS_POSITIVE,		/* Positively instantiated */
};

/*****************************************************************************/
/*
 * authentication token / access credential / keyring
 * - types of key include:
 *   - keyrings
 *   - disk encryption IDs
 *   - Kerberos TGTs and tickets
 */
struct key {
	refcount_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 {
		time64_t	expiry;		/* time at which key expires (or 0) */
		time64_t	revoked_at;	/* time at which key was revoked */
	};
	time64_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
						 */
	short			state;		/* Key state (+) or rejection error (-) */

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

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#define KEY_FLAG_REVOKED	1	/* set if key had been revoked */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

	/* 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;
		};
	};

	/* This is set on a keyring to restrict the addition of a link to a key
	 * to it.  If this structure isn't provided then it is assumed that the
	 * keyring is open to any addition.  It is ignored for non-keyring
	 * keys. Only set this value using keyring_restrict(), keyring_alloc(),
	 * or key_alloc().
	 *
	 * 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.
	 */
	struct key_restriction *restrict_link;
};

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,
			     struct key_restriction *restrict_link);


#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 */
#define KEY_ALLOC_UID_KEYRING		0x0010	/* allocating a user or user session keyring */

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)
{
	refcount_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,
				 struct key_restriction *restrict_link,
				 struct key *dest);

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

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 int keyring_restrict(key_ref_t keyring, const char *type,
			    const char *restriction);

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);

extern key_ref_t lookup_user_key(key_serial_t id, unsigned long flags,
				 key_perm_t perm);

/*
 * 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 */

static inline short key_read_state(const struct key *key)
{
	/* Barrier versus mark_key_instantiated(). */
	return smp_load_acquire(&key->state);
}

/**
 * key_is_positive - 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_positive(const struct key *key)
{
	return key_read_state(key) == KEY_IS_POSITIVE;
}

static inline bool key_is_negative(const struct key *key)
{
	return key_read_state(key) < 0;
}

#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
2874c5fd	1	/* SPDX-License-Identifier: GPL-2.0-or-later */
76181c13	2	/* Authentication token and access key management
1da177e4	3	*
76181c13	4	* Copyright (C) 2004, 2007 Red Hat, Inc. All Rights Reserved.
1da177e4 LT	5	* Written by David Howells (dhowells@redhat.com)
1da177e4 LT	6	*
b68101a1	7	* See Documentation/security/keys/core.rst for information on keys/keyrings.
1da177e4 LT	8	*/
	9
	10	#ifndef _LINUX_KEY_H
	11	#define _LINUX_KEY_H
	12
	13	#include <linux/types.h>
	14	#include <linux/list.h>
	15	#include <linux/rbtree.h>
76d8aeab	16	#include <linux/rcupdate.h>
0b77f5bf	17	#include <linux/sysctl.h>
aa84442d	18	#include <linux/rwsem.h>
60063497	19	#include <linux/atomic.h>
b2a4df20	20	#include <linux/assoc_array.h>
fff29291	21	#include <linux/refcount.h>
074d5898	22	#include <linux/time64.h>
1da177e4 LT	23
1da177e4 LT	24	#ifdef __KERNEL__
9a56c2db	25	#include <linux/uidgid.h>
1da177e4 LT	26
	27	/* key handle serial number */
	28	typedef int32_t key_serial_t;
	29
	30	/* key handle permissions mask */
	31	typedef uint32_t key_perm_t;
	32
	33	struct key;
	34
	35	#ifdef CONFIG_KEYS
	36
	37	#undef KEY_DEBUGGING
	38
664cceb0 DH	39	#define KEY_POS_VIEW 0x01000000 /* possessor can view a key's attributes */
	40	#define KEY_POS_READ 0x02000000 /* possessor can read key payload / view keyring */
	41	#define KEY_POS_WRITE 0x04000000 /* possessor can update key payload / add link to keyring */
	42	#define KEY_POS_SEARCH 0x08000000 /* possessor can find a key in search / search a keyring */
	43	#define KEY_POS_LINK 0x10000000 /* possessor can create a link to a key/keyring */
29db9190 DH	44	#define KEY_POS_SETATTR 0x20000000 /* possessor can set key attributes */
29db9190 DH	45	#define KEY_POS_ALL 0x3f000000
664cceb0 DH	46
	47	#define KEY_USR_VIEW 0x00010000 /* user permissions... */
	48	#define KEY_USR_READ 0x00020000
	49	#define KEY_USR_WRITE 0x00040000
	50	#define KEY_USR_SEARCH 0x00080000
	51	#define KEY_USR_LINK 0x00100000
29db9190 DH	52	#define KEY_USR_SETATTR 0x00200000
29db9190 DH	53	#define KEY_USR_ALL 0x003f0000
1da177e4 LT	54
	55	#define KEY_GRP_VIEW 0x00000100 /* group permissions... */
	56	#define KEY_GRP_READ 0x00000200
	57	#define KEY_GRP_WRITE 0x00000400
	58	#define KEY_GRP_SEARCH 0x00000800
	59	#define KEY_GRP_LINK 0x00001000
29db9190 DH	60	#define KEY_GRP_SETATTR 0x00002000
29db9190 DH	61	#define KEY_GRP_ALL 0x00003f00
1da177e4 LT	62
	63	#define KEY_OTH_VIEW 0x00000001 /* third party permissions... */
	64	#define KEY_OTH_READ 0x00000002
	65	#define KEY_OTH_WRITE 0x00000004
	66	#define KEY_OTH_SEARCH 0x00000008
	67	#define KEY_OTH_LINK 0x00000010
29db9190 DH	68	#define KEY_OTH_SETATTR 0x00000020
29db9190 DH	69	#define KEY_OTH_ALL 0x0000003f
1da177e4	70
6b79ccb5 AR	71	#define KEY_PERM_UNDEF 0xffffffff
6b79ccb5 AR	72
1da177e4 LT	73	struct seq_file;
	74	struct user_struct;
	75	struct signal_struct;
d84f4f99	76	struct cred;
1da177e4 LT	77
	78	struct key_type;
	79	struct key_owner;
	80	struct keyring_list;
	81	struct keyring_name;
	82
16feef43 DH	83	struct keyring_index_key {
	84	struct key_type *type;
	85	const char *description;
	86	size_t desc_len;
	87	};
	88
146aa8b1 DH	89	union key_payload {
	90	void __rcu *rcu_data0;
	91	void *data[4];
	92	};
	93
664cceb0 DH	94	/*****************************************************************************/
	95	/*
	96	* key reference with possession attribute handling
	97	*
	98	* NOTE! key_ref_t is a typedef'd pointer to a type that is not actually
	99	* defined. This is because we abuse the bottom bit of the reference to carry a
	100	* flag to indicate whether the calling process possesses that key in one of
	101	* its keyrings.
	102	*
	103	* the key_ref_t has been made a separate type so that the compiler can reject
	104	* attempts to dereference it without proper conversion.
	105	*
	106	* the three functions are used to assemble and disassemble references
	107	*/
	108	typedef struct __key_reference_with_attributes *key_ref_t;
	109
	110	static inline key_ref_t make_key_ref(const struct key *key,
a5b4bd28	111	bool possession)
664cceb0 DH	112	{
	113	return (key_ref_t) ((unsigned long) key \| possession);
	114	}
	115
	116	static inline struct key *key_ref_to_ptr(const key_ref_t key_ref)
	117	{
	118	return (struct key *) ((unsigned long) key_ref & ~1UL);
	119	}
	120
a5b4bd28	121	static inline bool is_key_possessed(const key_ref_t key_ref)
664cceb0 DH	122	{
	123	return (unsigned long) key_ref & 1UL;
	124	}
	125
aaf66c88	126	typedef int (key_restrict_link_func_t)(struct key dest_keyring,
469ff8f7	127	const struct key_type *type,
aaf66c88 MM	128	const union key_payload *payload,
aaf66c88 MM	129	struct key *restriction_key);
469ff8f7	130
e9cc0f68 MM	131	struct key_restriction {
	132	key_restrict_link_func_t check;
	133	struct key *key;
	134	struct key_type *keytype;
	135	};
	136
363b02da DH	137	enum key_state {
	138	KEY_IS_UNINSTANTIATED,
	139	KEY_IS_POSITIVE, /* Positively instantiated */
	140	};
	141
1da177e4 LT	142	/*****************************************************************************/
	143	/*
	144	* authentication token / access credential / keyring
	145	* - types of key include:
	146	* - keyrings
	147	* - disk encryption IDs
	148	* - Kerberos TGTs and tickets
	149	*/
	150	struct key {
fff29291	151	refcount_t usage; /* number of references */
1da177e4	152	key_serial_t serial; /* key serial number */
65d87fe6 DH	153	union {
	154	struct list_head graveyard_link;
	155	struct rb_node serial_node;
	156	};
1da177e4 LT	157	struct rw_semaphore sem; /* change vs change sem */
1da177e4 LT	158	struct key_user user; / owner of this key */
29db9190	159	void security; / security data for this key */
5d135440	160	union {
074d5898 BW	161	time64_t expiry; /* time at which key expires (or 0) */
074d5898 BW	162	time64_t revoked_at; /* time at which key was revoked */
5d135440	163	};
074d5898	164	time64_t last_used_at; /* last time used for LRU keyring discard */
9a56c2db EB	165	kuid_t uid;
9a56c2db EB	166	kgid_t gid;
1da177e4 LT	167	key_perm_t perm; /* access permissions */
1da177e4 LT	168	unsigned short quotalen; /* length added to quota */
76d8aeab DH	169	unsigned short datalen; /* payload data length
	170	* - may not match RCU dereferenced payload
	171	* - payload should contain own length
	172	*/
363b02da	173	short state; /* Key state (+) or rejection error (-) */
1da177e4 LT	174
	175	#ifdef KEY_DEBUGGING
	176	unsigned magic;
	177	#define KEY_DEBUG_MAGIC 0x18273645u
1da177e4 LT	178	#endif
1da177e4 LT	179
76d8aeab	180	unsigned long flags; /* status flags (change with bitops) */
363b02da DH	181	#define KEY_FLAG_DEAD 0 /* set if key type has been deleted */
	182	#define KEY_FLAG_REVOKED 1 /* set if key had been revoked */
	183	#define KEY_FLAG_IN_QUOTA 2 /* set if key consumes quota */
	184	#define KEY_FLAG_USER_CONSTRUCT 3 /* set if key is being constructed in userspace */
	185	#define KEY_FLAG_ROOT_CAN_CLEAR 4 /* set if key can be cleared by root without permission */
	186	#define KEY_FLAG_INVALIDATED 5 /* set if key has been invalidated */
	187	#define KEY_FLAG_BUILTIN 6 /* set if key is built in to the kernel */
	188	#define KEY_FLAG_ROOT_CAN_INVAL 7 /* set if key can be invalidated by root without permission */
	189	#define KEY_FLAG_KEEP 8 /* set if key should not be removed */
	190	#define KEY_FLAG_UID_KEYRING 9 /* set if key is a user or user session keyring */
76d8aeab	191
16feef43 DH	192	/* the key type and key description string
	193	* - the desc is used to match a key against search criteria
	194	* - it should be a printable string
1da177e4 LT	195	* - eg: for krb5 AFS, this might be "afs@REDHAT.COM"
1da177e4 LT	196	*/
16feef43 DH	197	union {
	198	struct keyring_index_key index_key;
	199	struct {
	200	struct key_type type; / type of key */
	201	char *description;
	202	};
	203	};
1da177e4	204
1da177e4 LT	205	/* key data
	206	* - this is used to hold the data actually used in cryptography or
	207	* whatever
	208	*/
	209	union {
146aa8b1 DH	210	union key_payload payload;
	211	struct {
	212	/* Keyring bits */
	213	struct list_head name_link;
	214	struct assoc_array keys;
	215	};
b2a4df20	216	};
5ac7eace DH	217
5ac7eace DH	218	/* This is set on a keyring to restrict the addition of a link to a key
2b6aa412	219	* to it. If this structure isn't provided then it is assumed that the
5ac7eace	220	* keyring is open to any addition. It is ignored for non-keyring
6563c91f MM	221	* keys. Only set this value using keyring_restrict(), keyring_alloc(),
6563c91f MM	222	* or key_alloc().
5ac7eace DH	223	*
	224	* This is intended for use with rings of trusted keys whereby addition
	225	* to the keyring needs to be controlled. KEY_ALLOC_BYPASS_RESTRICTION
	226	* overrides this, allowing the kernel to add extra keys without
	227	* restriction.
	228	*/
2b6aa412	229	struct key_restriction *restrict_link;
1da177e4 LT	230	};
1da177e4 LT	231
1da177e4 LT	232	extern struct key key_alloc(struct key_type type,
1da177e4 LT	233	const char *desc,
9a56c2db	234	kuid_t uid, kgid_t gid,
d84f4f99	235	const struct cred *cred,
7e047ef5	236	key_perm_t perm,
5ac7eace	237	unsigned long flags,
2b6aa412	238	struct key_restriction *restrict_link);
7e047ef5 DH	239
7e047ef5 DH	240
5ac7eace DH	241	#define KEY_ALLOC_IN_QUOTA 0x0000 /* add to quota, reject if would overrun */
	242	#define KEY_ALLOC_QUOTA_OVERRUN 0x0001 /* add to quota, permit even if overrun */
	243	#define KEY_ALLOC_NOT_IN_QUOTA 0x0002 /* not in quota */
77f68bac DH	244	#define KEY_ALLOC_BUILT_IN 0x0004 /* Key is built into kernel */
77f68bac DH	245	#define KEY_ALLOC_BYPASS_RESTRICTION 0x0008 /* Override the check on restricted keyrings */
237bbd29	246	#define KEY_ALLOC_UID_KEYRING 0x0010 /* allocating a user or user session keyring */
7e047ef5	247
1da177e4	248	extern void key_revoke(struct key *key);
fd75815f	249	extern void key_invalidate(struct key *key);
1da177e4 LT	250	extern void key_put(struct key *key);
1da177e4 LT	251
ccc3e6d9	252	static inline struct key __key_get(struct key key)
1da177e4	253	{
fff29291	254	refcount_inc(&key->usage);
1da177e4 LT	255	return key;
	256	}
	257
ccc3e6d9 DH	258	static inline struct key key_get(struct key key)
	259	{
	260	return key ? __key_get(key) : key;
	261	}
	262
664cceb0 DH	263	static inline void key_ref_put(key_ref_t key_ref)
	264	{
	265	key_put(key_ref_to_ptr(key_ref));
	266	}
	267
1da177e4 LT	268	extern struct key request_key(struct key_type type,
	269	const char *description,
	270	const char *callout_info);
	271
4e54f085 DH	272	extern struct key request_key_with_auxdata(struct key_type type,
4e54f085 DH	273	const char *description,
4a38e122 DH	274	const void *callout_info,
4a38e122 DH	275	size_t callout_len,
4e54f085 DH	276	void *aux);
4e54f085 DH	277
76181c13 DH	278	extern struct key request_key_async(struct key_type type,
76181c13 DH	279	const char *description,
4a38e122 DH	280	const void *callout_info,
4a38e122 DH	281	size_t callout_len);
76181c13 DH	282
	283	extern struct key request_key_async_with_auxdata(struct key_type type,
	284	const char *description,
4a38e122 DH	285	const void *callout_info,
4a38e122 DH	286	size_t callout_len,
76181c13 DH	287	void *aux);
	288
	289	extern int wait_for_key_construction(struct key *key, bool intr);
	290
b404aef7	291	extern int key_validate(const struct key *key);
1da177e4	292
664cceb0 DH	293	extern key_ref_t key_create_or_update(key_ref_t keyring,
	294	const char *type,
	295	const char *description,
	296	const void *payload,
	297	size_t plen,
6b79ccb5	298	key_perm_t perm,
7e047ef5	299	unsigned long flags);
1da177e4	300
664cceb0	301	extern int key_update(key_ref_t key,
1da177e4 LT	302	const void *payload,
	303	size_t plen);
	304
	305	extern int key_link(struct key *keyring,
	306	struct key *key);
	307
	308	extern int key_unlink(struct key *keyring,
	309	struct key *key);
	310
9a56c2db	311	extern struct key keyring_alloc(const char description, kuid_t uid, kgid_t gid,
d84f4f99	312	const struct cred *cred,
96b5c8fe	313	key_perm_t perm,
7e047ef5	314	unsigned long flags,
2b6aa412	315	struct key_restriction *restrict_link,
d720024e	316	struct key *dest);
1da177e4	317
5ac7eace DH	318	extern int restrict_link_reject(struct key *keyring,
5ac7eace DH	319	const struct key_type *type,
aaf66c88 MM	320	const union key_payload *payload,
aaf66c88 MM	321	struct key *restriction_key);
5ac7eace	322
1da177e4 LT	323	extern int keyring_clear(struct key *keyring);
1da177e4 LT	324
664cceb0 DH	325	extern key_ref_t keyring_search(key_ref_t keyring,
	326	struct key_type *type,
	327	const char *description);
1da177e4	328
1da177e4 LT	329	extern int keyring_add_key(struct key *keyring,
	330	struct key *key);
	331
6563c91f MM	332	extern int keyring_restrict(key_ref_t keyring, const char *type,
	333	const char *restriction);
	334
1da177e4 LT	335	extern struct key *key_lookup(key_serial_t id);
1da177e4 LT	336
456a8167	337	static inline key_serial_t key_serial(const struct key *key)
7249db2c DH	338	{
	339	return key ? key->serial : 0;
	340	}
1da177e4	341
59e6b9c1 BS	342	extern void key_set_timeout(struct key *, unsigned);
59e6b9c1 BS	343
76ef5e17 DJ	344	extern key_ref_t lookup_user_key(key_serial_t id, unsigned long flags,
	345	key_perm_t perm);
	346
f5895943 DH	347	/*
	348	* The permissions required on a key that we're looking up.
	349	*/
	350	#define KEY_NEED_VIEW 0x01 /* Require permission to view attributes */
	351	#define KEY_NEED_READ 0x02 /* Require permission to read content */
	352	#define KEY_NEED_WRITE 0x04 /* Require permission to update / modify */
	353	#define KEY_NEED_SEARCH 0x08 /* Require permission to search (keyring) or find (key) */
	354	#define KEY_NEED_LINK 0x10 /* Require permission to link */
	355	#define KEY_NEED_SETATTR 0x20 /* Require permission to change attributes */
	356	#define KEY_NEED_ALL 0x3f /* All the above permissions */
	357
363b02da DH	358	static inline short key_read_state(const struct key *key)
	359	{
	360	/* Barrier versus mark_key_instantiated(). */
	361	return smp_load_acquire(&key->state);
	362	}
	363
78b7280c	364	/**
363b02da	365	* key_is_positive - Determine if a key has been positively instantiated
78b7280c DH	366	* @key: The key to check.
	367	*
	368	* Return true if the specified key has been positively instantiated, false
	369	* otherwise.
	370	*/
363b02da DH	371	static inline bool key_is_positive(const struct key *key)
	372	{
	373	return key_read_state(key) == KEY_IS_POSITIVE;
	374	}
	375
	376	static inline bool key_is_negative(const struct key *key)
78b7280c	377	{
363b02da	378	return key_read_state(key) < 0;
78b7280c DH	379	}
78b7280c DH	380
0837e49a DH	381	#define dereference_key_rcu(KEY) \
	382	(rcu_dereference((KEY)->payload.rcu_data0))
	383
	384	#define dereference_key_locked(KEY) \
146aa8b1	385	(rcu_dereference_protected((KEY)->payload.rcu_data0, \
633e804e DH	386	rwsem_is_locked(&((struct key *)(KEY))->sem)))
633e804e DH	387
ee0b31a2	388	#define rcu_assign_keypointer(KEY, PAYLOAD) \
e5c1f444	389	do { \
146aa8b1	390	rcu_assign_pointer((KEY)->payload.rcu_data0, (PAYLOAD)); \
e5c1f444	391	} while (0)
ee0b31a2	392
0b77f5bf	393	#ifdef CONFIG_SYSCTL
d6f50c95	394	extern struct ctl_table key_sysctls[];
0b77f5bf	395	#endif
1da177e4 LT	396	/*
	397	* the userspace interface
	398	*/
d84f4f99	399	extern int install_thread_keyring_to_cred(struct cred *cred);
1da177e4 LT	400	extern void key_fsuid_changed(struct task_struct *tsk);
	401	extern void key_fsgid_changed(struct task_struct *tsk);
	402	extern void key_init(void);
	403
	404	#else /* CONFIG_KEYS */
	405
	406	#define key_validate(k) 0
	407	#define key_serial(k) 0
7888e7ff	408	#define key_get(k) ({ NULL; })
0dab9cfa	409	#define key_revoke(k) do { } while(0)
fd75815f	410	#define key_invalidate(k) do { } while(0)
1da177e4	411	#define key_put(k) do { } while(0)
664cceb0	412	#define key_ref_put(k) do { } while(0)
8bbf4976 DH	413	#define make_key_ref(k, p) NULL
8bbf4976 DH	414	#define key_ref_to_ptr(k) NULL
664cceb0	415	#define is_key_possessed(k) 0
1da177e4 LT	416	#define key_fsuid_changed(t) do { } while(0)
	417	#define key_fsgid_changed(t) do { } while(0)
	418	#define key_init() do { } while(0)
	419
	420	#endif /* CONFIG_KEYS */
	421	#endif /* __KERNEL__ */
	422	#endif /* _LINUX_KEY_H */