| /* 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 |
| */ |
| 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); |
| |
| /* 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 */ |