include/linux/key.h - kernel/msm-4.9 - Gitiles

 /* key.h: authentication token and access key management
  *
  * Copyright (C) 2004 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/keys.txt for information on keys/keyrings.
  */

 #ifndef _LINUX_KEY_H
 #define _LINUX_KEY_H

 #include <linux/types.h>
 #include <linux/list.h>
 #include <linux/rbtree.h>
 #include <linux/rcupdate.h>
 #include <asm/atomic.h>

 #ifdef __KERNEL__

 /* 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

 struct seq_file;
 struct user_struct;
 struct signal_struct;

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

 /*****************************************************************************/
 /*
  * 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,
 				     unsigned long 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 unsigned long is_key_possessed(const key_ref_t key_ref)
 {
 	return (unsigned long) key_ref & 1UL;
 }

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

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

 	unsigned long		flags;		/* status flags (change with bitops) */
 #define KEY_FLAG_INSTANTIATED	0	/* set if key has been instantiated */
 #define KEY_FLAG_DEAD		1	/* set if key type has been deleted */
 #define KEY_FLAG_REVOKED	2	/* set if key had been revoked */
 #define KEY_FLAG_IN_QUOTA	3	/* set if key consumes quota */
 #define KEY_FLAG_USER_CONSTRUCT	4	/* set if key is being constructed in userspace */
 #define KEY_FLAG_NEGATIVE	5	/* set if key is negative */

 	/* the description string
 	 * - this is used to match a key against search criteria
 	 * - this should be a printable string
 	 * - eg: for krb5 AFS, this might be "afs@REDHAT.COM"
 	 */
 	char			*description;

 	/* type specific data
 	 * - this is used by the keyring type to index the name
 	 */
 	union {
 		struct list_head	link;
 	} type_data;

 	/* key data
 	 * - this is used to hold the data actually used in cryptography or
 	 *   whatever
 	 */
 	union {
 		unsigned long		value;
 		void			*data;
 		struct keyring_list	*subscriptions;
 	} payload;
 };

 /*****************************************************************************/
 /*
  * kernel managed key type definition
  */
 typedef int (*request_key_actor_t)(struct key *key, struct key *authkey, const char *op);

 struct key_type {
 	/* name of the type */
 	const char *name;

 	/* default payload length for quota precalculation (optional)
 	 * - this can be used instead of calling key_payload_reserve(), that
 	 *   function only needs to be called if the real datalen is different
 	 */
 	size_t def_datalen;

 	/* instantiate a key of this type
 	 * - this method should call key_payload_reserve() to determine if the
 	 *   user's quota will hold the payload
 	 */
 	int (*instantiate)(struct key *key, const void *data, size_t datalen);

 	/* update a key of this type (optional)
 	 * - this method should call key_payload_reserve() to recalculate the
 	 *   quota consumption
 	 * - the key must be locked against read when modifying
 	 */
 	int (*update)(struct key *key, const void *data, size_t datalen);

 	/* match a key against a description */
 	int (*match)(const struct key *key, const void *desc);

 	/* clear the data from a key (optional) */
 	void (*destroy)(struct key *key);

 	/* describe a key */
 	void (*describe)(const struct key *key, struct seq_file *p);

 	/* read a key's data (optional)
 	 * - permission checks will be done by the caller
 	 * - the key's semaphore will be readlocked by the caller
 	 * - should return the amount of data that could be read, no matter how
 	 *   much is copied into the buffer
 	 * - shouldn't do the copy if the buffer is NULL
 	 */
 	long (*read)(const struct key *key, char __user *buffer, size_t buflen);

 	/* handle request_key() for this type instead of invoking
 	 * /sbin/request-key (optional)
 	 * - key is the key to instantiate
 	 * - authkey is the authority to assume when instantiating this key
 	 * - op is the operation to be done, usually "create"
 	 * - the call must not return until the instantiation process has run
 	 *   its course
 	 */
 	request_key_actor_t request_key;

 	/* internal fields */
 	struct list_head	link;		/* link in types list */
 };

 extern struct key_type key_type_keyring;

 extern int register_key_type(struct key_type *ktype);
 extern void unregister_key_type(struct key_type *ktype);

 extern struct key *key_alloc(struct key_type *type,
 			     const char *desc,
 			     uid_t uid, gid_t gid, key_perm_t perm,
 			     int not_in_quota);
 extern int key_payload_reserve(struct key *key, size_t datalen);
 extern int key_instantiate_and_link(struct key *key,
 				    const void *data,
 				    size_t datalen,
 				    struct key *keyring,
 				    struct key *instkey);
 extern int key_negate_and_link(struct key *key,
 			       unsigned timeout,
 			       struct key *keyring,
 			       struct key *instkey);
 extern void key_revoke(struct key *key);
 extern void key_put(struct key *key);

 static inline struct key *key_get(struct key *key)
 {
 	if (key)
 		atomic_inc(&key->usage);
 	return 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 int key_validate(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,
 				      int not_in_quota);

 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, uid_t uid, gid_t gid,
 				 int not_in_quota, struct key *dest);

 extern int keyring_clear(struct key *keyring);

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

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

 extern struct key *key_lookup(key_serial_t id);

 extern void keyring_replace_payload(struct key *key, void *replacement);

 #define key_serial(key) ((key) ? (key)->serial : 0)

 /*
  * the userspace interface
  */
 extern struct key root_user_keyring, root_session_keyring;
 extern int alloc_uid_keyring(struct user_struct *user);
 extern void switch_uid_keyring(struct user_struct *new_user);
 extern int copy_keys(unsigned long clone_flags, struct task_struct *tsk);
 extern int copy_thread_group_keys(struct task_struct *tsk);
 extern void exit_keys(struct task_struct *tsk);
 extern void exit_thread_group_keys(struct signal_struct *tg);
 extern int suid_keys(struct task_struct *tsk);
 extern int exec_keys(struct task_struct *tsk);
 extern void key_fsuid_changed(struct task_struct *tsk);
 extern void key_fsgid_changed(struct task_struct *tsk);
 extern void key_init(void);

 #define __install_session_keyring(tsk, keyring)			\
 ({								\
 	struct key *old_session = tsk->signal->session_keyring;	\
 	tsk->signal->session_keyring = keyring;			\
 	old_session;						\
 })

 #else /* CONFIG_KEYS */

 #define key_validate(k)			0
 #define key_serial(k)			0
 #define key_get(k) 			({ NULL; })
 #define key_put(k)			do { } while(0)
 #define key_ref_put(k)			do { } while(0)
 #define make_key_ref(k)			({ NULL; })
 #define key_ref_to_ptr(k)		({ NULL; })
 #define is_key_possessed(k)		0
 #define alloc_uid_keyring(u)		0
 #define switch_uid_keyring(u)		do { } while(0)
 #define __install_session_keyring(t, k)	({ NULL; })
 #define copy_keys(f,t)			0
 #define copy_thread_group_keys(t)	0
 #define exit_keys(t)			do { } while(0)
 #define exit_thread_group_keys(tg)	do { } while(0)
 #define suid_keys(t)			do { } while(0)
 #define exec_keys(t)			do { } while(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 */
	/* key.h: authentication token and access key management
	*
	* Copyright (C) 2004 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/keys.txt for information on keys/keyrings.
	*/

	#ifndef _LINUX_KEY_H
	#define _LINUX_KEY_H

	#include <linux/types.h>
	#include <linux/list.h>
	#include <linux/rbtree.h>
	#include <linux/rcupdate.h>
	#include <asm/atomic.h>

	#ifdef __KERNEL__

	/* 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

	struct seq_file;
	struct user_struct;
	struct signal_struct;

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

	/*****************************************************************************/
	/*
	* 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,
	unsigned long 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 unsigned long is_key_possessed(const key_ref_t key_ref)
	{
	return (unsigned long) key_ref & 1UL;
	}

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

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

	unsigned long flags; /* status flags (change with bitops) */
	#define KEY_FLAG_INSTANTIATED 0 /* set if key has been instantiated */
	#define KEY_FLAG_DEAD 1 /* set if key type has been deleted */
	#define KEY_FLAG_REVOKED 2 /* set if key had been revoked */
	#define KEY_FLAG_IN_QUOTA 3 /* set if key consumes quota */
	#define KEY_FLAG_USER_CONSTRUCT 4 /* set if key is being constructed in userspace */
	#define KEY_FLAG_NEGATIVE 5 /* set if key is negative */

	/* the description string
	* - this is used to match a key against search criteria
	* - this should be a printable string
	* - eg: for krb5 AFS, this might be "afs@REDHAT.COM"
	*/
	char *description;

	/* type specific data
	* - this is used by the keyring type to index the name
	*/
	union {
	struct list_head link;
	} type_data;

	/* key data
	* - this is used to hold the data actually used in cryptography or
	* whatever
	*/
	union {
	unsigned long value;
	void *data;
	struct keyring_list *subscriptions;
	} payload;
	};

	/*****************************************************************************/
	/*
	* kernel managed key type definition
	*/
	typedef int (request_key_actor_t)(struct key key, struct key authkey, const char op);

	struct key_type {
	/* name of the type */
	const char *name;

	/* default payload length for quota precalculation (optional)
	* - this can be used instead of calling key_payload_reserve(), that
	* function only needs to be called if the real datalen is different
	*/
	size_t def_datalen;

	/* instantiate a key of this type
	* - this method should call key_payload_reserve() to determine if the
	* user's quota will hold the payload
	*/
	int (instantiate)(struct key key, const void *data, size_t datalen);

	/* update a key of this type (optional)
	* - this method should call key_payload_reserve() to recalculate the
	* quota consumption
	* - the key must be locked against read when modifying
	*/
	int (update)(struct key key, const void *data, size_t datalen);

	/* match a key against a description */
	int (match)(const struct key key, const void *desc);

	/* clear the data from a key (optional) */
	void (destroy)(struct key key);

	/* describe a key */
	void (describe)(const struct key key, struct seq_file *p);

	/* read a key's data (optional)
	* - permission checks will be done by the caller
	* - the key's semaphore will be readlocked by the caller
	* - should return the amount of data that could be read, no matter how
	* much is copied into the buffer
	* - shouldn't do the copy if the buffer is NULL
	*/
	long (read)(const struct key key, char __user *buffer, size_t buflen);

	/* handle request_key() for this type instead of invoking
	* /sbin/request-key (optional)
	* - key is the key to instantiate
	* - authkey is the authority to assume when instantiating this key
	* - op is the operation to be done, usually "create"
	* - the call must not return until the instantiation process has run
	* its course
	*/
	request_key_actor_t request_key;

	/* internal fields */
	struct list_head link; /* link in types list */
	};

	extern struct key_type key_type_keyring;

	extern int register_key_type(struct key_type *ktype);
	extern void unregister_key_type(struct key_type *ktype);

	extern struct key key_alloc(struct key_type type,
	const char *desc,
	uid_t uid, gid_t gid, key_perm_t perm,
	int not_in_quota);
	extern int key_payload_reserve(struct key *key, size_t datalen);
	extern int key_instantiate_and_link(struct key *key,
	const void *data,
	size_t datalen,
	struct key *keyring,
	struct key *instkey);
	extern int key_negate_and_link(struct key *key,
	unsigned timeout,
	struct key *keyring,
	struct key *instkey);
	extern void key_revoke(struct key *key);
	extern void key_put(struct key *key);

	static inline struct key key_get(struct key key)
	{
	if (key)
	atomic_inc(&key->usage);
	return 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 int key_validate(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,
	int not_in_quota);

	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, uid_t uid, gid_t gid,
	int not_in_quota, struct key *dest);

	extern int keyring_clear(struct key *keyring);

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

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

	extern struct key *key_lookup(key_serial_t id);

	extern void keyring_replace_payload(struct key key, void replacement);

	#define key_serial(key) ((key) ? (key)->serial : 0)

	/*
	* the userspace interface
	*/
	extern struct key root_user_keyring, root_session_keyring;
	extern int alloc_uid_keyring(struct user_struct *user);
	extern void switch_uid_keyring(struct user_struct *new_user);
	extern int copy_keys(unsigned long clone_flags, struct task_struct *tsk);
	extern int copy_thread_group_keys(struct task_struct *tsk);
	extern void exit_keys(struct task_struct *tsk);
	extern void exit_thread_group_keys(struct signal_struct *tg);
	extern int suid_keys(struct task_struct *tsk);
	extern int exec_keys(struct task_struct *tsk);
	extern void key_fsuid_changed(struct task_struct *tsk);
	extern void key_fsgid_changed(struct task_struct *tsk);
	extern void key_init(void);

	#define __install_session_keyring(tsk, keyring) \
	({ \
	struct key *old_session = tsk->signal->session_keyring; \
	tsk->signal->session_keyring = keyring; \
	old_session; \
	})

	#else /* CONFIG_KEYS */

	#define key_validate(k) 0
	#define key_serial(k) 0
	#define key_get(k) ({ NULL; })
	#define key_put(k) do { } while(0)
	#define key_ref_put(k) do { } while(0)
	#define make_key_ref(k) ({ NULL; })
	#define key_ref_to_ptr(k) ({ NULL; })
	#define is_key_possessed(k) 0
	#define alloc_uid_keyring(u) 0
	#define switch_uid_keyring(u) do { } while(0)
	#define __install_session_keyring(t, k) ({ NULL; })
	#define copy_keys(f,t) 0
	#define copy_thread_group_keys(t) 0
	#define exit_keys(t) do { } while(0)
	#define exit_thread_group_keys(tg) do { } while(0)
	#define suid_keys(t) do { } while(0)
	#define exec_keys(t) do { } while(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 */