diff options
Diffstat (limited to 'include/linux/key.h')
| -rw-r--r-- | include/linux/key.h | 230 |
1 files changed, 171 insertions, 59 deletions
diff --git a/include/linux/key.h b/include/linux/key.h index 044114185120..81b8f05c6898 100644 --- a/include/linux/key.h +++ b/include/linux/key.h @@ -1,14 +1,9 @@ +/* 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) * - * 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. */ @@ -24,6 +19,7 @@ #include <linux/atomic.h> #include <linux/assoc_array.h> #include <linux/refcount.h> +#include <linux/time64.h> #ifdef __KERNEL__ #include <linux/uidgid.h> @@ -35,6 +31,7 @@ typedef int32_t key_serial_t; typedef uint32_t key_perm_t; struct key; +struct net; #ifdef CONFIG_KEYS @@ -74,6 +71,29 @@ struct key; #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 */ +}; + +enum key_lookup_flag { + KEY_LOOKUP_CREATE = 0x01, + KEY_LOOKUP_PARTIAL = 0x02, + KEY_LOOKUP_ALL = (KEY_LOOKUP_CREATE | KEY_LOOKUP_PARTIAL), +}; + struct seq_file; struct user_struct; struct signal_struct; @@ -81,13 +101,34 @@ 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; - size_t desc_len; }; union key_payload { @@ -138,6 +179,11 @@ struct key_restriction { struct key_type *keytype; }; +enum key_state { + KEY_IS_UNINSTANTIATED, + KEY_IS_POSITIVE, /* Positively instantiated */ +}; + /*****************************************************************************/ /* * authentication token / access credential / keyring @@ -153,14 +199,17 @@ struct key { 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 { - time_t expiry; /* time at which key expires (or 0) */ - time_t revoked_at; /* time at which key was revoked */ + time64_t expiry; /* time at which key expires (or 0) */ + time64_t revoked_at; /* time at which key was revoked */ }; - time_t last_used_at; /* last time used for LRU keyring discard */ + time64_t last_used_at; /* last time used for LRU keyring discard */ kuid_t uid; kgid_t gid; key_perm_t perm; /* access permissions */ @@ -169,6 +218,7 @@ struct key { * - may not match RCU dereferenced payload * - payload should contain own length */ + short state; /* Key state (+) or rejection error (-) */ #ifdef KEY_DEBUGGING unsigned magic; @@ -176,17 +226,17 @@ struct key { #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 */ -#define KEY_FLAG_ROOT_CAN_CLEAR 6 /* set if key can be cleared by root without permission */ -#define KEY_FLAG_INVALIDATED 7 /* set if key has been invalidated */ -#define KEY_FLAG_BUILTIN 8 /* set if key is built in to the kernel */ -#define KEY_FLAG_ROOT_CAN_INVAL 9 /* set if key can be invalidated by root without permission */ -#define KEY_FLAG_KEEP 10 /* set if key should not be removed */ +#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 */ +#define KEY_FLAG_USER_ALIVE 10 /* set if final put has not happened on key yet */ /* the key type and key description string * - the desc is used to match a key against search criteria @@ -196,7 +246,10 @@ struct key { 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; }; }; @@ -212,7 +265,6 @@ struct key { struct list_head name_link; struct assoc_array keys; }; - int reject_error; }; /* This is set on a keyring to restrict the addition of a link to a key @@ -243,10 +295,14 @@ extern struct key *key_alloc(struct key_type *type, #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) { @@ -264,31 +320,81 @@ 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_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); -extern struct key *request_key_async(struct key_type *type, - const char *description, - const void *callout_info, - size_t callout_len); +/** + * 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) -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); +/** + * 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(key_ref_t keyring, + const char *type, + const char *description, + const void *payload, + size_t plen, + key_perm_t perm, + unsigned long flags); + extern key_ref_t key_create_or_update(key_ref_t keyring, const char *type, const char *description, @@ -304,6 +410,11 @@ extern int key_update(key_ref_t key, 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); @@ -323,10 +434,8 @@ 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); + const char *description, + bool recurse); extern int keyring_restrict(key_ref_t keyring, const char *type, const char *restriction); @@ -340,28 +449,31 @@ static inline key_serial_t key_serial(const struct key *key) 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 */ +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_instantiated - Determine if a key has been positively instantiated + * 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_instantiated(const struct key *key) +static inline bool key_is_positive(const struct key *key) { - return test_bit(KEY_FLAG_INSTANTIATED, &key->flags) && - !test_bit(KEY_FLAG_NEGATIVE, &key->flags); + 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) \ @@ -376,15 +488,12 @@ 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_fsuid_changed(struct cred *new_cred); +extern void key_fsgid_changed(struct cred *new_cred); extern void key_init(void); #else /* CONFIG_KEYS */ @@ -399,9 +508,12 @@ extern void key_init(void); #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_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) +#define key_lookup(k) NULL #endif /* CONFIG_KEYS */ #endif /* __KERNEL__ */ |
