[mirror_ubuntu-bionic-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/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>

#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 {
		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
						 */
	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);

/*
 * 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
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	*
b68101a1	12	* See Documentation/security/keys/core.rst 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>
fff29291	26	#include <linux/refcount.h>
1da177e4 LT	27
1da177e4 LT	28	#ifdef __KERNEL__
9a56c2db	29	#include <linux/uidgid.h>
1da177e4 LT	30
	31	/* key handle serial number */
	32	typedef int32_t key_serial_t;
	33
	34	/* key handle permissions mask */
	35	typedef uint32_t key_perm_t;
	36
	37	struct key;
	38
	39	#ifdef CONFIG_KEYS
	40
	41	#undef KEY_DEBUGGING
	42
664cceb0 DH	43	#define KEY_POS_VIEW 0x01000000 /* possessor can view a key's attributes */
	44	#define KEY_POS_READ 0x02000000 /* possessor can read key payload / view keyring */
	45	#define KEY_POS_WRITE 0x04000000 /* possessor can update key payload / add link to keyring */
	46	#define KEY_POS_SEARCH 0x08000000 /* possessor can find a key in search / search a keyring */
	47	#define KEY_POS_LINK 0x10000000 /* possessor can create a link to a key/keyring */
29db9190 DH	48	#define KEY_POS_SETATTR 0x20000000 /* possessor can set key attributes */
29db9190 DH	49	#define KEY_POS_ALL 0x3f000000
664cceb0 DH	50
	51	#define KEY_USR_VIEW 0x00010000 /* user permissions... */
	52	#define KEY_USR_READ 0x00020000
	53	#define KEY_USR_WRITE 0x00040000
	54	#define KEY_USR_SEARCH 0x00080000
	55	#define KEY_USR_LINK 0x00100000
29db9190 DH	56	#define KEY_USR_SETATTR 0x00200000
29db9190 DH	57	#define KEY_USR_ALL 0x003f0000
1da177e4 LT	58
	59	#define KEY_GRP_VIEW 0x00000100 /* group permissions... */
	60	#define KEY_GRP_READ 0x00000200
	61	#define KEY_GRP_WRITE 0x00000400
	62	#define KEY_GRP_SEARCH 0x00000800
	63	#define KEY_GRP_LINK 0x00001000
29db9190 DH	64	#define KEY_GRP_SETATTR 0x00002000
29db9190 DH	65	#define KEY_GRP_ALL 0x00003f00
1da177e4 LT	66
	67	#define KEY_OTH_VIEW 0x00000001 /* third party permissions... */
	68	#define KEY_OTH_READ 0x00000002
	69	#define KEY_OTH_WRITE 0x00000004
	70	#define KEY_OTH_SEARCH 0x00000008
	71	#define KEY_OTH_LINK 0x00000010
29db9190 DH	72	#define KEY_OTH_SETATTR 0x00000020
29db9190 DH	73	#define KEY_OTH_ALL 0x0000003f
1da177e4	74
6b79ccb5 AR	75	#define KEY_PERM_UNDEF 0xffffffff
6b79ccb5 AR	76
1da177e4 LT	77	struct seq_file;
	78	struct user_struct;
	79	struct signal_struct;
d84f4f99	80	struct cred;
1da177e4 LT	81
	82	struct key_type;
	83	struct key_owner;
	84	struct keyring_list;
	85	struct keyring_name;
	86
16feef43 DH	87	struct keyring_index_key {
	88	struct key_type *type;
	89	const char *description;
	90	size_t desc_len;
	91	};
	92
146aa8b1 DH	93	union key_payload {
	94	void __rcu *rcu_data0;
	95	void *data[4];
	96	};
	97
664cceb0 DH	98	/*****************************************************************************/
	99	/*
	100	* key reference with possession attribute handling
	101	*
	102	* NOTE! key_ref_t is a typedef'd pointer to a type that is not actually
	103	* defined. This is because we abuse the bottom bit of the reference to carry a
	104	* flag to indicate whether the calling process possesses that key in one of
	105	* its keyrings.
	106	*
	107	* the key_ref_t has been made a separate type so that the compiler can reject
	108	* attempts to dereference it without proper conversion.
	109	*
	110	* the three functions are used to assemble and disassemble references
	111	*/
	112	typedef struct __key_reference_with_attributes *key_ref_t;
	113
	114	static inline key_ref_t make_key_ref(const struct key *key,
a5b4bd28	115	bool possession)
664cceb0 DH	116	{
	117	return (key_ref_t) ((unsigned long) key \| possession);
	118	}
	119
	120	static inline struct key *key_ref_to_ptr(const key_ref_t key_ref)
	121	{
	122	return (struct key *) ((unsigned long) key_ref & ~1UL);
	123	}
	124
a5b4bd28	125	static inline bool is_key_possessed(const key_ref_t key_ref)
664cceb0 DH	126	{
	127	return (unsigned long) key_ref & 1UL;
	128	}
	129
aaf66c88	130	typedef int (key_restrict_link_func_t)(struct key dest_keyring,
469ff8f7	131	const struct key_type *type,
aaf66c88 MM	132	const union key_payload *payload,
aaf66c88 MM	133	struct key *restriction_key);
469ff8f7	134
e9cc0f68 MM	135	struct key_restriction {
	136	key_restrict_link_func_t check;
	137	struct key *key;
	138	struct key_type *keytype;
	139	};
	140
363b02da DH	141	enum key_state {
	142	KEY_IS_UNINSTANTIATED,
	143	KEY_IS_POSITIVE, /* Positively instantiated */
	144	};
	145
1da177e4 LT	146	/*****************************************************************************/
	147	/*
	148	* authentication token / access credential / keyring
	149	* - types of key include:
	150	* - keyrings
	151	* - disk encryption IDs
	152	* - Kerberos TGTs and tickets
	153	*/
	154	struct key {
fff29291	155	refcount_t usage; /* number of references */
1da177e4	156	key_serial_t serial; /* key serial number */
65d87fe6 DH	157	union {
	158	struct list_head graveyard_link;
	159	struct rb_node serial_node;
	160	};
1da177e4 LT	161	struct rw_semaphore sem; /* change vs change sem */
1da177e4 LT	162	struct key_user user; / owner of this key */
29db9190	163	void security; / security data for this key */
5d135440 DH	164	union {
	165	time_t expiry; /* time at which key expires (or 0) */
	166	time_t revoked_at; /* time at which key was revoked */
	167	};
31d5a79d	168	time_t last_used_at; /* last time used for LRU keyring discard */
9a56c2db EB	169	kuid_t uid;
9a56c2db EB	170	kgid_t gid;
1da177e4 LT	171	key_perm_t perm; /* access permissions */
1da177e4 LT	172	unsigned short quotalen; /* length added to quota */
76d8aeab DH	173	unsigned short datalen; /* payload data length
	174	* - may not match RCU dereferenced payload
	175	* - payload should contain own length
	176	*/
363b02da	177	short state; /* Key state (+) or rejection error (-) */
1da177e4 LT	178
	179	#ifdef KEY_DEBUGGING
	180	unsigned magic;
	181	#define KEY_DEBUG_MAGIC 0x18273645u
1da177e4 LT	182	#endif
1da177e4 LT	183
76d8aeab	184	unsigned long flags; /* status flags (change with bitops) */
363b02da DH	185	#define KEY_FLAG_DEAD 0 /* set if key type has been deleted */
	186	#define KEY_FLAG_REVOKED 1 /* set if key had been revoked */
	187	#define KEY_FLAG_IN_QUOTA 2 /* set if key consumes quota */
	188	#define KEY_FLAG_USER_CONSTRUCT 3 /* set if key is being constructed in userspace */
	189	#define KEY_FLAG_ROOT_CAN_CLEAR 4 /* set if key can be cleared by root without permission */
	190	#define KEY_FLAG_INVALIDATED 5 /* set if key has been invalidated */
	191	#define KEY_FLAG_BUILTIN 6 /* set if key is built in to the kernel */
	192	#define KEY_FLAG_ROOT_CAN_INVAL 7 /* set if key can be invalidated by root without permission */
	193	#define KEY_FLAG_KEEP 8 /* set if key should not be removed */
	194	#define KEY_FLAG_UID_KEYRING 9 /* set if key is a user or user session keyring */
76d8aeab	195
16feef43 DH	196	/* the key type and key description string
	197	* - the desc is used to match a key against search criteria
	198	* - it should be a printable string
1da177e4 LT	199	* - eg: for krb5 AFS, this might be "afs@REDHAT.COM"
1da177e4 LT	200	*/
16feef43 DH	201	union {
	202	struct keyring_index_key index_key;
	203	struct {
	204	struct key_type type; / type of key */
	205	char *description;
	206	};
	207	};
1da177e4	208
1da177e4 LT	209	/* key data
	210	* - this is used to hold the data actually used in cryptography or
	211	* whatever
	212	*/
	213	union {
146aa8b1 DH	214	union key_payload payload;
	215	struct {
	216	/* Keyring bits */
	217	struct list_head name_link;
	218	struct assoc_array keys;
	219	};
b2a4df20	220	};
5ac7eace DH	221
5ac7eace DH	222	/* This is set on a keyring to restrict the addition of a link to a key
2b6aa412	223	* to it. If this structure isn't provided then it is assumed that the
5ac7eace	224	* keyring is open to any addition. It is ignored for non-keyring
6563c91f MM	225	* keys. Only set this value using keyring_restrict(), keyring_alloc(),
6563c91f MM	226	* or key_alloc().
5ac7eace DH	227	*
	228	* This is intended for use with rings of trusted keys whereby addition
	229	* to the keyring needs to be controlled. KEY_ALLOC_BYPASS_RESTRICTION
	230	* overrides this, allowing the kernel to add extra keys without
	231	* restriction.
	232	*/
2b6aa412	233	struct key_restriction *restrict_link;
1da177e4 LT	234	};
1da177e4 LT	235
1da177e4 LT	236	extern struct key key_alloc(struct key_type type,
1da177e4 LT	237	const char *desc,
9a56c2db	238	kuid_t uid, kgid_t gid,
d84f4f99	239	const struct cred *cred,
7e047ef5	240	key_perm_t perm,
5ac7eace	241	unsigned long flags,
2b6aa412	242	struct key_restriction *restrict_link);
7e047ef5 DH	243
7e047ef5 DH	244
5ac7eace DH	245	#define KEY_ALLOC_IN_QUOTA 0x0000 /* add to quota, reject if would overrun */
	246	#define KEY_ALLOC_QUOTA_OVERRUN 0x0001 /* add to quota, permit even if overrun */
	247	#define KEY_ALLOC_NOT_IN_QUOTA 0x0002 /* not in quota */
77f68bac DH	248	#define KEY_ALLOC_BUILT_IN 0x0004 /* Key is built into kernel */
77f68bac DH	249	#define KEY_ALLOC_BYPASS_RESTRICTION 0x0008 /* Override the check on restricted keyrings */
237bbd29	250	#define KEY_ALLOC_UID_KEYRING 0x0010 /* allocating a user or user session keyring */
7e047ef5	251
1da177e4	252	extern void key_revoke(struct key *key);
fd75815f	253	extern void key_invalidate(struct key *key);
1da177e4 LT	254	extern void key_put(struct key *key);
1da177e4 LT	255
ccc3e6d9	256	static inline struct key __key_get(struct key key)
1da177e4	257	{
fff29291	258	refcount_inc(&key->usage);
1da177e4 LT	259	return key;
	260	}
	261
ccc3e6d9 DH	262	static inline struct key key_get(struct key key)
	263	{
	264	return key ? __key_get(key) : key;
	265	}
	266
664cceb0 DH	267	static inline void key_ref_put(key_ref_t key_ref)
	268	{
	269	key_put(key_ref_to_ptr(key_ref));
	270	}
	271
1da177e4 LT	272	extern struct key request_key(struct key_type type,
	273	const char *description,
	274	const char *callout_info);
	275
4e54f085 DH	276	extern struct key request_key_with_auxdata(struct key_type type,
4e54f085 DH	277	const char *description,
4a38e122 DH	278	const void *callout_info,
4a38e122 DH	279	size_t callout_len,
4e54f085 DH	280	void *aux);
4e54f085 DH	281
76181c13 DH	282	extern struct key request_key_async(struct key_type type,
76181c13 DH	283	const char *description,
4a38e122 DH	284	const void *callout_info,
4a38e122 DH	285	size_t callout_len);
76181c13 DH	286
	287	extern struct key request_key_async_with_auxdata(struct key_type type,
	288	const char *description,
4a38e122 DH	289	const void *callout_info,
4a38e122 DH	290	size_t callout_len,
76181c13 DH	291	void *aux);
	292
	293	extern int wait_for_key_construction(struct key *key, bool intr);
	294
b404aef7	295	extern int key_validate(const struct key *key);
1da177e4	296
664cceb0 DH	297	extern key_ref_t key_create_or_update(key_ref_t keyring,
	298	const char *type,
	299	const char *description,
	300	const void *payload,
	301	size_t plen,
6b79ccb5	302	key_perm_t perm,
7e047ef5	303	unsigned long flags);
1da177e4	304
664cceb0	305	extern int key_update(key_ref_t key,
1da177e4 LT	306	const void *payload,
	307	size_t plen);
	308
	309	extern int key_link(struct key *keyring,
	310	struct key *key);
	311
	312	extern int key_unlink(struct key *keyring,
	313	struct key *key);
	314
9a56c2db	315	extern struct key keyring_alloc(const char description, kuid_t uid, kgid_t gid,
d84f4f99	316	const struct cred *cred,
96b5c8fe	317	key_perm_t perm,
7e047ef5	318	unsigned long flags,
2b6aa412	319	struct key_restriction *restrict_link,
d720024e	320	struct key *dest);
1da177e4	321
5ac7eace DH	322	extern int restrict_link_reject(struct key *keyring,
5ac7eace DH	323	const struct key_type *type,
aaf66c88 MM	324	const union key_payload *payload,
aaf66c88 MM	325	struct key *restriction_key);
5ac7eace	326
1da177e4 LT	327	extern int keyring_clear(struct key *keyring);
1da177e4 LT	328
664cceb0 DH	329	extern key_ref_t keyring_search(key_ref_t keyring,
	330	struct key_type *type,
	331	const char *description);
1da177e4	332
1da177e4 LT	333	extern int keyring_add_key(struct key *keyring,
	334	struct key *key);
	335
6563c91f MM	336	extern int keyring_restrict(key_ref_t keyring, const char *type,
	337	const char *restriction);
	338
1da177e4 LT	339	extern struct key *key_lookup(key_serial_t id);
1da177e4 LT	340
456a8167	341	static inline key_serial_t key_serial(const struct key *key)
7249db2c DH	342	{
	343	return key ? key->serial : 0;
	344	}
1da177e4	345
59e6b9c1 BS	346	extern void key_set_timeout(struct key *, unsigned);
59e6b9c1 BS	347
f5895943 DH	348	/*
	349	* The permissions required on a key that we're looking up.
	350	*/
	351	#define KEY_NEED_VIEW 0x01 /* Require permission to view attributes */
	352	#define KEY_NEED_READ 0x02 /* Require permission to read content */
	353	#define KEY_NEED_WRITE 0x04 /* Require permission to update / modify */
	354	#define KEY_NEED_SEARCH 0x08 /* Require permission to search (keyring) or find (key) */
	355	#define KEY_NEED_LINK 0x10 /* Require permission to link */
	356	#define KEY_NEED_SETATTR 0x20 /* Require permission to change attributes */
	357	#define KEY_NEED_ALL 0x3f /* All the above permissions */
	358
363b02da DH	359	static inline short key_read_state(const struct key *key)
	360	{
	361	/* Barrier versus mark_key_instantiated(). */
	362	return smp_load_acquire(&key->state);
	363	}
	364
78b7280c	365	/**
363b02da	366	* key_is_positive - Determine if a key has been positively instantiated
78b7280c DH	367	* @key: The key to check.
	368	*
	369	* Return true if the specified key has been positively instantiated, false
	370	* otherwise.
	371	*/
363b02da DH	372	static inline bool key_is_positive(const struct key *key)
	373	{
	374	return key_read_state(key) == KEY_IS_POSITIVE;
	375	}
	376
	377	static inline bool key_is_negative(const struct key *key)
78b7280c	378	{
363b02da	379	return key_read_state(key) < 0;
78b7280c DH	380	}
78b7280c DH	381
0837e49a DH	382	#define dereference_key_rcu(KEY) \
	383	(rcu_dereference((KEY)->payload.rcu_data0))
	384
	385	#define dereference_key_locked(KEY) \
146aa8b1	386	(rcu_dereference_protected((KEY)->payload.rcu_data0, \
633e804e DH	387	rwsem_is_locked(&((struct key *)(KEY))->sem)))
633e804e DH	388
ee0b31a2	389	#define rcu_assign_keypointer(KEY, PAYLOAD) \
e5c1f444	390	do { \
146aa8b1	391	rcu_assign_pointer((KEY)->payload.rcu_data0, (PAYLOAD)); \
e5c1f444	392	} while (0)
ee0b31a2	393
0b77f5bf	394	#ifdef CONFIG_SYSCTL
d6f50c95	395	extern struct ctl_table key_sysctls[];
0b77f5bf	396	#endif
1da177e4 LT	397	/*
	398	* the userspace interface
	399	*/
d84f4f99	400	extern int install_thread_keyring_to_cred(struct cred *cred);
1da177e4 LT	401	extern void key_fsuid_changed(struct task_struct *tsk);
	402	extern void key_fsgid_changed(struct task_struct *tsk);
	403	extern void key_init(void);
	404
	405	#else /* CONFIG_KEYS */
	406
	407	#define key_validate(k) 0
	408	#define key_serial(k) 0
7888e7ff	409	#define key_get(k) ({ NULL; })
0dab9cfa	410	#define key_revoke(k) do { } while(0)
fd75815f	411	#define key_invalidate(k) do { } while(0)
1da177e4	412	#define key_put(k) do { } while(0)
664cceb0	413	#define key_ref_put(k) do { } while(0)
8bbf4976 DH	414	#define make_key_ref(k, p) NULL
8bbf4976 DH	415	#define key_ref_to_ptr(k) NULL
664cceb0	416	#define is_key_possessed(k) 0
1da177e4 LT	417	#define key_fsuid_changed(t) do { } while(0)
	418	#define key_fsgid_changed(t) do { } while(0)
	419	#define key_init() do { } while(0)
	420
	421	#endif /* CONFIG_KEYS */
	422	#endif /* __KERNEL__ */
	423	#endif /* _LINUX_KEY_H */