| /* 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.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 <linux/sysctl.h> |
| #include <linux/rwsem.h> |
| #include <linux/atomic.h> |
| #include <linux/assoc_array.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; |
| } |
| |
| 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 { |
| atomic_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 |
| #define KEY_DEBUG_MAGIC_X 0xf8e9dacbu |
| #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 method isn't provided then it is assumed that the |
| * keyring is open to any addition. It is ignored for non-keyring |
| * keys. |
| * |
| * 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. |
| */ |
| int (*restrict_link)(struct key *keyring, |
| const struct key_type *type, |
| const union key_payload *payload); |
| }; |
| |
| 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, |
| int (*restrict_link)(struct key *, |
| const struct key_type *, |
| const union key_payload *)); |
| |
| |
| #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) |
| { |
| atomic_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, |
| int (*restrict_link)(struct key *, |
| const struct key_type *, |
| const union key_payload *), |
| struct key *dest); |
| |
| extern int restrict_link_reject(struct key *keyring, |
| const struct key_type *type, |
| const union key_payload *payload); |
| |
| 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); |
| |
| 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 */ |