From 2c3c1048746a4622d8c89a29670120dc8fab93c4 Mon Sep 17 00:00:00 2001 From: Daniel Baumann Date: Sun, 7 Apr 2024 20:49:45 +0200 Subject: Adding upstream version 6.1.76. Signed-off-by: Daniel Baumann --- include/linux/key.h | 516 ++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 516 insertions(+) create mode 100644 include/linux/key.h (limited to 'include/linux/key.h') diff --git a/include/linux/key.h b/include/linux/key.h new file mode 100644 index 000000000..d27477faf --- /dev/null +++ b/include/linux/key.h @@ -0,0 +1,516 @@ +/* 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 +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#ifdef __KERNEL__ +#include + +/* 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 */ +}; + +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; +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 */ -- cgit v1.2.3