[linux-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;
struct net;

#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

/*
 * The permissions required on a key that we're looking up.
 */
enum key_need_perm {
	KEY_NEED_UNSPECIFIED,	/* Needed permission unspecified */
	KEY_NEED_VIEW,		/* Require permission to view attributes */
	KEY_NEED_READ,		/* Require permission to read content */
	KEY_NEED_WRITE,		/* Require permission to update / modify */
	KEY_NEED_SEARCH,	/* Require permission to search (keyring) or find (key) */
	KEY_NEED_LINK,		/* Require permission to link */
	KEY_NEED_SETATTR,	/* Require permission to change attributes */
	KEY_NEED_UNLINK,	/* Require permission to unlink key */
	KEY_SYSADMIN_OVERRIDE,	/* Special: override by CAP_SYS_ADMIN */
	KEY_AUTHTOKEN_OVERRIDE,	/* Special: override by possession of auth token */
	KEY_DEFER_PERM_CHECK,	/* Special: permission check is deferred */
};

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

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

struct key_tag {
	struct rcu_head		rcu;
	refcount_t		usage;
	bool			removed;	/* T when subject removed */
};

struct keyring_index_key {
	/* [!] If this structure is altered, the union in struct key must change too! */
	unsigned long		hash;			/* Hash value */
	union {
		struct {
#ifdef __LITTLE_ENDIAN /* Put desc_len at the LSB of x */
			u16	desc_len;
			char	desc[sizeof(long) - 2];	/* First few chars of description */
#else
			char	desc[sizeof(long) - 2];	/* First few chars of description */
			u16	desc_len;
#endif
		};
		unsigned long x;
	};
	struct key_type		*type;
	struct key_tag		*domain_tag;	/* Domain of operation */
	const char		*description;
};

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;
	};
#ifdef CONFIG_KEY_NOTIFICATIONS
	struct watch_list	*watchers;	/* Entities watching this key for changes */
#endif
	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 {
			unsigned long	hash;
			unsigned long	len_desc;
			struct key_type	*type;		/* type of key */
			struct key_tag	*domain_tag;	/* Domain of operation */
			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 */
#define KEY_ALLOC_SET_KEEP		0x0020	/* Set the KEEP flag on the key/keyring */

extern void key_revoke(struct key *key);
extern void key_invalidate(struct key *key);
extern void key_put(struct key *key);
extern bool key_put_tag(struct key_tag *tag);
extern void key_remove_domain(struct key_tag *domain_tag);

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_tag(struct key_type *type,
				   const char *description,
				   struct key_tag *domain_tag,
				   const char *callout_info);

extern struct key *request_key_rcu(struct key_type *type,
				   const char *description,
				   struct key_tag *domain_tag);

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

/**
 * request_key - Request a key and wait for construction
 * @type: Type of key.
 * @description: The searchable description of the key.
 * @callout_info: The data to pass to the instantiation upcall (or NULL).
 *
 * As for request_key_tag(), but with the default global domain tag.
 */
static inline struct key *request_key(struct key_type *type,
				      const char *description,
				      const char *callout_info)
{
	return request_key_tag(type, description, NULL, callout_info);
}

#ifdef CONFIG_NET
/**
 * request_key_net - Request a key for a net namespace and wait for construction
 * @type: Type of key.
 * @description: The searchable description of the key.
 * @net: The network namespace that is the key's domain of operation.
 * @callout_info: The data to pass to the instantiation upcall (or NULL).
 *
 * As for request_key() except that it does not add the returned key to a
 * keyring if found, new keys are always allocated in the user's quota, the
 * callout_info must be a NUL-terminated string and no auxiliary data can be
 * passed.  Only keys that operate the specified network namespace are used.
 *
 * Furthermore, it then works as wait_for_key_construction() to wait for the
 * completion of keys undergoing construction with a non-interruptible wait.
 */
#define request_key_net(type, description, net, callout_info) \
	request_key_tag(type, description, net->key_domain, callout_info)

/**
 * request_key_net_rcu - Request a key for a net namespace under RCU conditions
 * @type: Type of key.
 * @description: The searchable description of the key.
 * @net: The network namespace that is the key's domain of operation.
 *
 * As for request_key_rcu() except that only keys that operate the specified
 * network namespace are used.
 */
#define request_key_net_rcu(type, description, net) \
	request_key_rcu(type, description, net->key_domain)
#endif /* CONFIG_NET */

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_move(struct key *key,
		    struct key *from_keyring,
		    struct key *to_keyring,
		    unsigned int flags);

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,
				bool recurse);

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,
				 enum key_need_perm need_perm);
extern void key_free_user_ns(struct user_namespace *);

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 cred *new_cred);
extern void key_fsgid_changed(struct cred *new_cred);
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(c)		do { } while(0)
#define key_fsgid_changed(c)		do { } while(0)
#define key_init()			do { } while(0)
#define key_free_user_ns(ns)		do { } while(0)
#define key_remove_domain(d)		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
028db3e2 LT	30	/* key handle permissions mask */
	31	typedef uint32_t key_perm_t;
	32
1da177e4	33	struct key;
a58946c1	34	struct net;
1da177e4 LT	35
	36	#ifdef CONFIG_KEYS
	37
2e12256b	38	#undef KEY_DEBUGGING
6b79ccb5	39
028db3e2 LT	40	#define KEY_POS_VIEW 0x01000000 /* possessor can view a key's attributes */
	41	#define KEY_POS_READ 0x02000000 /* possessor can read key payload / view keyring */
	42	#define KEY_POS_WRITE 0x04000000 /* possessor can update key payload / add link to keyring */
	43	#define KEY_POS_SEARCH 0x08000000 /* possessor can find a key in search / search a keyring */
	44	#define KEY_POS_LINK 0x10000000 /* possessor can create a link to a key/keyring */
	45	#define KEY_POS_SETATTR 0x20000000 /* possessor can set key attributes */
	46	#define KEY_POS_ALL 0x3f000000
	47
	48	#define KEY_USR_VIEW 0x00010000 /* user permissions... */
	49	#define KEY_USR_READ 0x00020000
	50	#define KEY_USR_WRITE 0x00040000
	51	#define KEY_USR_SEARCH 0x00080000
	52	#define KEY_USR_LINK 0x00100000
	53	#define KEY_USR_SETATTR 0x00200000
	54	#define KEY_USR_ALL 0x003f0000
	55
	56	#define KEY_GRP_VIEW 0x00000100 /* group permissions... */
	57	#define KEY_GRP_READ 0x00000200
	58	#define KEY_GRP_WRITE 0x00000400
	59	#define KEY_GRP_SEARCH 0x00000800
	60	#define KEY_GRP_LINK 0x00001000
	61	#define KEY_GRP_SETATTR 0x00002000
	62	#define KEY_GRP_ALL 0x00003f00
	63
	64	#define KEY_OTH_VIEW 0x00000001 /* third party permissions... */
	65	#define KEY_OTH_READ 0x00000002
	66	#define KEY_OTH_WRITE 0x00000004
	67	#define KEY_OTH_SEARCH 0x00000008
	68	#define KEY_OTH_LINK 0x00000010
	69	#define KEY_OTH_SETATTR 0x00000020
	70	#define KEY_OTH_ALL 0x0000003f
	71
	72	#define KEY_PERM_UNDEF 0xffffffff
	73
8c0637e9 DH	74	/*
	75	* The permissions required on a key that we're looking up.
	76	*/
	77	enum key_need_perm {
	78	KEY_NEED_UNSPECIFIED, /* Needed permission unspecified */
	79	KEY_NEED_VIEW, /* Require permission to view attributes */
	80	KEY_NEED_READ, /* Require permission to read content */
	81	KEY_NEED_WRITE, /* Require permission to update / modify */
	82	KEY_NEED_SEARCH, /* Require permission to search (keyring) or find (key) */
	83	KEY_NEED_LINK, /* Require permission to link */
	84	KEY_NEED_SETATTR, /* Require permission to change attributes */
	85	KEY_NEED_UNLINK, /* Require permission to unlink key */
	86	KEY_SYSADMIN_OVERRIDE, /* Special: override by CAP_SYS_ADMIN */
	87	KEY_AUTHTOKEN_OVERRIDE, /* Special: override by possession of auth token */
	88	KEY_DEFER_PERM_CHECK, /* Special: permission check is deferred */
	89	};
	90
1da177e4 LT	91	struct seq_file;
	92	struct user_struct;
	93	struct signal_struct;
d84f4f99	94	struct cred;
1da177e4 LT	95
	96	struct key_type;
	97	struct key_owner;
3b6e4de0	98	struct key_tag;
1da177e4 LT	99	struct keyring_list;
	100	struct keyring_name;
	101
3b6e4de0 DH	102	struct key_tag {
	103	struct rcu_head rcu;
	104	refcount_t usage;
	105	bool removed; /* T when subject removed */
	106	};
	107
16feef43	108	struct keyring_index_key {
355ef8e1 DH	109	/* [!] If this structure is altered, the union in struct key must change too! */
355ef8e1 DH	110	unsigned long hash; /* Hash value */
f771fde8 DH	111	union {
	112	struct {
	113	#ifdef __LITTLE_ENDIAN /* Put desc_len at the LSB of x */
555df336 DH	114	u16 desc_len;
555df336 DH	115	char desc[sizeof(long) - 2]; /* First few chars of description */
f771fde8	116	#else
555df336 DH	117	char desc[sizeof(long) - 2]; /* First few chars of description */
555df336 DH	118	u16 desc_len;
f771fde8 DH	119	#endif
	120	};
	121	unsigned long x;
	122	};
16feef43	123	struct key_type *type;
3b6e4de0	124	struct key_tag domain_tag; / Domain of operation */
16feef43	125	const char *description;
16feef43 DH	126	};
16feef43 DH	127
146aa8b1 DH	128	union key_payload {
	129	void __rcu *rcu_data0;
	130	void *data[4];
	131	};
	132
664cceb0 DH	133	/*****************************************************************************/
	134	/*
	135	* key reference with possession attribute handling
	136	*
	137	* NOTE! key_ref_t is a typedef'd pointer to a type that is not actually
	138	* defined. This is because we abuse the bottom bit of the reference to carry a
	139	* flag to indicate whether the calling process possesses that key in one of
	140	* its keyrings.
	141	*
	142	* the key_ref_t has been made a separate type so that the compiler can reject
	143	* attempts to dereference it without proper conversion.
	144	*
	145	* the three functions are used to assemble and disassemble references
	146	*/
	147	typedef struct __key_reference_with_attributes *key_ref_t;
	148
	149	static inline key_ref_t make_key_ref(const struct key *key,
a5b4bd28	150	bool possession)
664cceb0 DH	151	{
	152	return (key_ref_t) ((unsigned long) key \| possession);
	153	}
	154
	155	static inline struct key *key_ref_to_ptr(const key_ref_t key_ref)
	156	{
	157	return (struct key *) ((unsigned long) key_ref & ~1UL);
	158	}
	159
a5b4bd28	160	static inline bool is_key_possessed(const key_ref_t key_ref)
664cceb0 DH	161	{
	162	return (unsigned long) key_ref & 1UL;
	163	}
	164
aaf66c88	165	typedef int (key_restrict_link_func_t)(struct key dest_keyring,
469ff8f7	166	const struct key_type *type,
aaf66c88 MM	167	const union key_payload *payload,
aaf66c88 MM	168	struct key *restriction_key);
469ff8f7	169
e9cc0f68 MM	170	struct key_restriction {
	171	key_restrict_link_func_t check;
	172	struct key *key;
	173	struct key_type *keytype;
	174	};
	175
363b02da DH	176	enum key_state {
	177	KEY_IS_UNINSTANTIATED,
	178	KEY_IS_POSITIVE, /* Positively instantiated */
	179	};
	180
1da177e4 LT	181	/*****************************************************************************/
	182	/*
	183	* authentication token / access credential / keyring
	184	* - types of key include:
	185	* - keyrings
	186	* - disk encryption IDs
	187	* - Kerberos TGTs and tickets
	188	*/
	189	struct key {
fff29291	190	refcount_t usage; /* number of references */
1da177e4	191	key_serial_t serial; /* key serial number */
65d87fe6 DH	192	union {
	193	struct list_head graveyard_link;
	194	struct rb_node serial_node;
	195	};
f7e47677 DH	196	#ifdef CONFIG_KEY_NOTIFICATIONS
	197	struct watch_list watchers; / Entities watching this key for changes */
	198	#endif
1da177e4 LT	199	struct rw_semaphore sem; /* change vs change sem */
1da177e4 LT	200	struct key_user user; / owner of this key */
29db9190	201	void security; / security data for this key */
5d135440	202	union {
074d5898 BW	203	time64_t expiry; /* time at which key expires (or 0) */
074d5898 BW	204	time64_t revoked_at; /* time at which key was revoked */
5d135440	205	};
074d5898	206	time64_t last_used_at; /* last time used for LRU keyring discard */
9a56c2db EB	207	kuid_t uid;
9a56c2db EB	208	kgid_t gid;
028db3e2	209	key_perm_t perm; /* access permissions */
1da177e4	210	unsigned short quotalen; /* length added to quota */
76d8aeab DH	211	unsigned short datalen; /* payload data length
	212	* - may not match RCU dereferenced payload
	213	* - payload should contain own length
	214	*/
363b02da	215	short state; /* Key state (+) or rejection error (-) */
1da177e4 LT	216
	217	#ifdef KEY_DEBUGGING
	218	unsigned magic;
	219	#define KEY_DEBUG_MAGIC 0x18273645u
1da177e4 LT	220	#endif
1da177e4 LT	221
76d8aeab	222	unsigned long flags; /* status flags (change with bitops) */
363b02da DH	223	#define KEY_FLAG_DEAD 0 /* set if key type has been deleted */
	224	#define KEY_FLAG_REVOKED 1 /* set if key had been revoked */
	225	#define KEY_FLAG_IN_QUOTA 2 /* set if key consumes quota */
	226	#define KEY_FLAG_USER_CONSTRUCT 3 /* set if key is being constructed in userspace */
	227	#define KEY_FLAG_ROOT_CAN_CLEAR 4 /* set if key can be cleared by root without permission */
	228	#define KEY_FLAG_INVALIDATED 5 /* set if key has been invalidated */
	229	#define KEY_FLAG_BUILTIN 6 /* set if key is built in to the kernel */
	230	#define KEY_FLAG_ROOT_CAN_INVAL 7 /* set if key can be invalidated by root without permission */
	231	#define KEY_FLAG_KEEP 8 /* set if key should not be removed */
	232	#define KEY_FLAG_UID_KEYRING 9 /* set if key is a user or user session keyring */
76d8aeab	233
16feef43 DH	234	/* the key type and key description string
	235	* - the desc is used to match a key against search criteria
	236	* - it should be a printable string
1da177e4 LT	237	* - eg: for krb5 AFS, this might be "afs@REDHAT.COM"
1da177e4 LT	238	*/
16feef43 DH	239	union {
	240	struct keyring_index_key index_key;
	241	struct {
355ef8e1	242	unsigned long hash;
f771fde8	243	unsigned long len_desc;
16feef43	244	struct key_type type; / type of key */
3b6e4de0	245	struct key_tag domain_tag; / Domain of operation */
16feef43 DH	246	char *description;
	247	};
	248	};
1da177e4	249
1da177e4 LT	250	/* key data
	251	* - this is used to hold the data actually used in cryptography or
	252	* whatever
	253	*/
	254	union {
146aa8b1 DH	255	union key_payload payload;
	256	struct {
	257	/* Keyring bits */
	258	struct list_head name_link;
	259	struct assoc_array keys;
	260	};
b2a4df20	261	};
5ac7eace DH	262
5ac7eace DH	263	/* This is set on a keyring to restrict the addition of a link to a key
2b6aa412	264	* to it. If this structure isn't provided then it is assumed that the
5ac7eace	265	* keyring is open to any addition. It is ignored for non-keyring
6563c91f MM	266	* keys. Only set this value using keyring_restrict(), keyring_alloc(),
6563c91f MM	267	* or key_alloc().
5ac7eace DH	268	*
	269	* This is intended for use with rings of trusted keys whereby addition
	270	* to the keyring needs to be controlled. KEY_ALLOC_BYPASS_RESTRICTION
	271	* overrides this, allowing the kernel to add extra keys without
	272	* restriction.
	273	*/
2b6aa412	274	struct key_restriction *restrict_link;
1da177e4 LT	275	};
1da177e4 LT	276
1da177e4 LT	277	extern struct key key_alloc(struct key_type type,
1da177e4 LT	278	const char *desc,
9a56c2db	279	kuid_t uid, kgid_t gid,
d84f4f99	280	const struct cred *cred,
028db3e2	281	key_perm_t perm,
5ac7eace	282	unsigned long flags,
2b6aa412	283	struct key_restriction *restrict_link);
7e047ef5 DH	284
7e047ef5 DH	285
5ac7eace DH	286	#define KEY_ALLOC_IN_QUOTA 0x0000 /* add to quota, reject if would overrun */
	287	#define KEY_ALLOC_QUOTA_OVERRUN 0x0001 /* add to quota, permit even if overrun */
	288	#define KEY_ALLOC_NOT_IN_QUOTA 0x0002 /* not in quota */
77f68bac DH	289	#define KEY_ALLOC_BUILT_IN 0x0004 /* Key is built into kernel */
77f68bac DH	290	#define KEY_ALLOC_BYPASS_RESTRICTION 0x0008 /* Override the check on restricted keyrings */
237bbd29	291	#define KEY_ALLOC_UID_KEYRING 0x0010 /* allocating a user or user session keyring */
4993e1f9	292	#define KEY_ALLOC_SET_KEEP 0x0020 /* Set the KEEP flag on the key/keyring */
7e047ef5	293
1da177e4	294	extern void key_revoke(struct key *key);
fd75815f	295	extern void key_invalidate(struct key *key);
1da177e4	296	extern void key_put(struct key *key);
3b6e4de0	297	extern bool key_put_tag(struct key_tag *tag);
218e6424	298	extern void key_remove_domain(struct key_tag *domain_tag);
1da177e4	299
ccc3e6d9	300	static inline struct key __key_get(struct key key)
1da177e4	301	{
fff29291	302	refcount_inc(&key->usage);
1da177e4 LT	303	return key;
	304	}
	305
ccc3e6d9 DH	306	static inline struct key key_get(struct key key)
	307	{
	308	return key ? __key_get(key) : key;
	309	}
	310
664cceb0 DH	311	static inline void key_ref_put(key_ref_t key_ref)
	312	{
	313	key_put(key_ref_to_ptr(key_ref));
	314	}
	315
a58946c1 DH	316	extern struct key request_key_tag(struct key_type type,
	317	const char *description,
	318	struct key_tag *domain_tag,
028db3e2	319	const char *callout_info);
1da177e4	320
896f1950	321	extern struct key request_key_rcu(struct key_type type,
a58946c1 DH	322	const char *description,
a58946c1 DH	323	struct key_tag *domain_tag);
896f1950	324
4e54f085 DH	325	extern struct key request_key_with_auxdata(struct key_type type,
4e54f085 DH	326	const char *description,
a58946c1	327	struct key_tag *domain_tag,
4a38e122 DH	328	const void *callout_info,
4a38e122 DH	329	size_t callout_len,
028db3e2	330	void *aux);
76181c13	331
a58946c1 DH	332	/**
	333	* request_key - Request a key and wait for construction
	334	* @type: Type of key.
	335	* @description: The searchable description of the key.
	336	* @callout_info: The data to pass to the instantiation upcall (or NULL).
	337	*
	338	* As for request_key_tag(), but with the default global domain tag.
	339	*/
	340	static inline struct key request_key(struct key_type type,
	341	const char *description,
028db3e2	342	const char *callout_info)
a58946c1	343	{
028db3e2	344	return request_key_tag(type, description, NULL, callout_info);
a58946c1 DH	345	}
	346
	347	#ifdef CONFIG_NET
8b6a666a	348	/**
a58946c1 DH	349	* request_key_net - Request a key for a net namespace and wait for construction
	350	* @type: Type of key.
	351	* @description: The searchable description of the key.
	352	* @net: The network namespace that is the key's domain of operation.
	353	* @callout_info: The data to pass to the instantiation upcall (or NULL).
	354	*
	355	* As for request_key() except that it does not add the returned key to a
	356	* keyring if found, new keys are always allocated in the user's quota, the
	357	* callout_info must be a NUL-terminated string and no auxiliary data can be
	358	* passed. Only keys that operate the specified network namespace are used.
	359	*
	360	* Furthermore, it then works as wait_for_key_construction() to wait for the
	361	* completion of keys undergoing construction with a non-interruptible wait.
	362	*/
028db3e2	363	#define request_key_net(type, description, net, callout_info) \
464e96ae	364	request_key_tag(type, description, net->key_domain, callout_info)
8b6a666a DH	365
	366	/**
	367	* request_key_net_rcu - Request a key for a net namespace under RCU conditions
	368	* @type: Type of key.
	369	* @description: The searchable description of the key.
	370	* @net: The network namespace that is the key's domain of operation.
	371	*
	372	* As for request_key_rcu() except that only keys that operate the specified
	373	* network namespace are used.
	374	*/
	375	#define request_key_net_rcu(type, description, net) \
464e96ae	376	request_key_rcu(type, description, net->key_domain)
a58946c1 DH	377	#endif /* CONFIG_NET */
a58946c1 DH	378
76181c13 DH	379	extern int wait_for_key_construction(struct key *key, bool intr);
76181c13 DH	380
b404aef7	381	extern int key_validate(const struct key *key);
1da177e4	382
664cceb0 DH	383	extern key_ref_t key_create_or_update(key_ref_t keyring,
	384	const char *type,
	385	const char *description,
	386	const void *payload,
	387	size_t plen,
028db3e2	388	key_perm_t perm,
7e047ef5	389	unsigned long flags);
1da177e4	390
664cceb0	391	extern int key_update(key_ref_t key,
1da177e4 LT	392	const void *payload,
	393	size_t plen);
	394
	395	extern int key_link(struct key *keyring,
	396	struct key *key);
	397
ed0ac5c7 DH	398	extern int key_move(struct key *key,
	399	struct key *from_keyring,
	400	struct key *to_keyring,
	401	unsigned int flags);
	402
1da177e4 LT	403	extern int key_unlink(struct key *keyring,
	404	struct key *key);
	405
9a56c2db	406	extern struct key keyring_alloc(const char description, kuid_t uid, kgid_t gid,
d84f4f99	407	const struct cred *cred,
028db3e2	408	key_perm_t perm,
7e047ef5	409	unsigned long flags,
2b6aa412	410	struct key_restriction *restrict_link,
d720024e	411	struct key *dest);
1da177e4	412
5ac7eace DH	413	extern int restrict_link_reject(struct key *keyring,
5ac7eace DH	414	const struct key_type *type,
aaf66c88 MM	415	const union key_payload *payload,
aaf66c88 MM	416	struct key *restriction_key);
5ac7eace	417
1da177e4 LT	418	extern int keyring_clear(struct key *keyring);
1da177e4 LT	419
664cceb0 DH	420	extern key_ref_t keyring_search(key_ref_t keyring,
664cceb0 DH	421	struct key_type *type,
dcf49dbc DH	422	const char *description,
dcf49dbc DH	423	bool recurse);
1da177e4	424
1da177e4 LT	425	extern int keyring_add_key(struct key *keyring,
	426	struct key *key);
	427
6563c91f MM	428	extern int keyring_restrict(key_ref_t keyring, const char *type,
	429	const char *restriction);
	430
1da177e4 LT	431	extern struct key *key_lookup(key_serial_t id);
1da177e4 LT	432
456a8167	433	static inline key_serial_t key_serial(const struct key *key)
7249db2c DH	434	{
	435	return key ? key->serial : 0;
	436	}
1da177e4	437
59e6b9c1 BS	438	extern void key_set_timeout(struct key *, unsigned);
59e6b9c1 BS	439
76ef5e17	440	extern key_ref_t lookup_user_key(key_serial_t id, unsigned long flags,
8c0637e9	441	enum key_need_perm need_perm);
b206f281	442	extern void key_free_user_ns(struct user_namespace *);
76ef5e17	443
363b02da DH	444	static inline short key_read_state(const struct key *key)
	445	{
	446	/* Barrier versus mark_key_instantiated(). */
	447	return smp_load_acquire(&key->state);
	448	}
	449
78b7280c	450	/**
363b02da	451	* key_is_positive - Determine if a key has been positively instantiated
78b7280c DH	452	* @key: The key to check.
	453	*
	454	* Return true if the specified key has been positively instantiated, false
	455	* otherwise.
	456	*/
363b02da DH	457	static inline bool key_is_positive(const struct key *key)
	458	{
	459	return key_read_state(key) == KEY_IS_POSITIVE;
	460	}
	461
	462	static inline bool key_is_negative(const struct key *key)
78b7280c	463	{
363b02da	464	return key_read_state(key) < 0;
78b7280c DH	465	}
78b7280c DH	466
0837e49a DH	467	#define dereference_key_rcu(KEY) \
	468	(rcu_dereference((KEY)->payload.rcu_data0))
	469
	470	#define dereference_key_locked(KEY) \
146aa8b1	471	(rcu_dereference_protected((KEY)->payload.rcu_data0, \
633e804e DH	472	rwsem_is_locked(&((struct key *)(KEY))->sem)))
633e804e DH	473
ee0b31a2	474	#define rcu_assign_keypointer(KEY, PAYLOAD) \
e5c1f444	475	do { \
146aa8b1	476	rcu_assign_pointer((KEY)->payload.rcu_data0, (PAYLOAD)); \
e5c1f444	477	} while (0)
ee0b31a2	478
0b77f5bf	479	#ifdef CONFIG_SYSCTL
d6f50c95	480	extern struct ctl_table key_sysctls[];
0b77f5bf	481	#endif
1da177e4 LT	482	/*
	483	* the userspace interface
	484	*/
d84f4f99	485	extern int install_thread_keyring_to_cred(struct cred *cred);
2e21865f DH	486	extern void key_fsuid_changed(struct cred *new_cred);
2e21865f DH	487	extern void key_fsgid_changed(struct cred *new_cred);
1da177e4 LT	488	extern void key_init(void);
	489
	490	#else /* CONFIG_KEYS */
	491
	492	#define key_validate(k) 0
	493	#define key_serial(k) 0
7888e7ff	494	#define key_get(k) ({ NULL; })
0dab9cfa	495	#define key_revoke(k) do { } while(0)
fd75815f	496	#define key_invalidate(k) do { } while(0)
1da177e4	497	#define key_put(k) do { } while(0)
664cceb0	498	#define key_ref_put(k) do { } while(0)
8bbf4976 DH	499	#define make_key_ref(k, p) NULL
8bbf4976 DH	500	#define key_ref_to_ptr(k) NULL
664cceb0	501	#define is_key_possessed(k) 0
2e21865f DH	502	#define key_fsuid_changed(c) do { } while(0)
2e21865f DH	503	#define key_fsgid_changed(c) do { } while(0)
1da177e4	504	#define key_init() do { } while(0)
b206f281	505	#define key_free_user_ns(ns) do { } while(0)
218e6424	506	#define key_remove_domain(d) do { } while(0)
1da177e4 LT	507
	508	#endif /* CONFIG_KEYS */
	509	#endif /* __KERNEL__ */
	510	#endif /* _LINUX_KEY_H */