linux/security/keys/internal.h
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   1/* SPDX-License-Identifier: GPL-2.0-or-later */
   2/* Authentication token and access key management internal defs
   3 *
   4 * Copyright (C) 2003-5, 2007 Red Hat, Inc. All Rights Reserved.
   5 * Written by David Howells (dhowells@redhat.com)
   6 */
   7
   8#ifndef _INTERNAL_H
   9#define _INTERNAL_H
  10
  11#include <linux/sched.h>
  12#include <linux/wait_bit.h>
  13#include <linux/cred.h>
  14#include <linux/key-type.h>
  15#include <linux/task_work.h>
  16#include <linux/keyctl.h>
  17#include <linux/refcount.h>
  18#include <linux/watch_queue.h>
  19#include <linux/compat.h>
  20#include <linux/mm.h>
  21#include <linux/vmalloc.h>
  22
  23struct iovec;
  24
  25#ifdef __KDEBUG
  26#define kenter(FMT, ...) \
  27        printk(KERN_DEBUG "==> %s("FMT")\n", __func__, ##__VA_ARGS__)
  28#define kleave(FMT, ...) \
  29        printk(KERN_DEBUG "<== %s()"FMT"\n", __func__, ##__VA_ARGS__)
  30#define kdebug(FMT, ...) \
  31        printk(KERN_DEBUG "   "FMT"\n", ##__VA_ARGS__)
  32#else
  33#define kenter(FMT, ...) \
  34        no_printk(KERN_DEBUG "==> %s("FMT")\n", __func__, ##__VA_ARGS__)
  35#define kleave(FMT, ...) \
  36        no_printk(KERN_DEBUG "<== %s()"FMT"\n", __func__, ##__VA_ARGS__)
  37#define kdebug(FMT, ...) \
  38        no_printk(KERN_DEBUG FMT"\n", ##__VA_ARGS__)
  39#endif
  40
  41extern struct key_type key_type_dead;
  42extern struct key_type key_type_user;
  43extern struct key_type key_type_logon;
  44
  45/*****************************************************************************/
  46/*
  47 * Keep track of keys for a user.
  48 *
  49 * This needs to be separate to user_struct to avoid a refcount-loop
  50 * (user_struct pins some keyrings which pin this struct).
  51 *
  52 * We also keep track of keys under request from userspace for this UID here.
  53 */
  54struct key_user {
  55        struct rb_node          node;
  56        struct mutex            cons_lock;      /* construction initiation lock */
  57        spinlock_t              lock;
  58        refcount_t              usage;          /* for accessing qnkeys & qnbytes */
  59        atomic_t                nkeys;          /* number of keys */
  60        atomic_t                nikeys;         /* number of instantiated keys */
  61        kuid_t                  uid;
  62        int                     qnkeys;         /* number of keys allocated to this user */
  63        int                     qnbytes;        /* number of bytes allocated to this user */
  64};
  65
  66extern struct rb_root   key_user_tree;
  67extern spinlock_t       key_user_lock;
  68extern struct key_user  root_key_user;
  69
  70extern struct key_user *key_user_lookup(kuid_t uid);
  71extern void key_user_put(struct key_user *user);
  72
  73/*
  74 * Key quota limits.
  75 * - root has its own separate limits to everyone else
  76 */
  77extern unsigned key_quota_root_maxkeys;
  78extern unsigned key_quota_root_maxbytes;
  79extern unsigned key_quota_maxkeys;
  80extern unsigned key_quota_maxbytes;
  81
  82#define KEYQUOTA_LINK_BYTES     4               /* a link in a keyring is worth 4 bytes */
  83
  84
  85extern struct kmem_cache *key_jar;
  86extern struct rb_root key_serial_tree;
  87extern spinlock_t key_serial_lock;
  88extern struct mutex key_construction_mutex;
  89extern wait_queue_head_t request_key_conswq;
  90
  91extern void key_set_index_key(struct keyring_index_key *index_key);
  92extern struct key_type *key_type_lookup(const char *type);
  93extern void key_type_put(struct key_type *ktype);
  94
  95extern int __key_link_lock(struct key *keyring,
  96                           const struct keyring_index_key *index_key);
  97extern int __key_move_lock(struct key *l_keyring, struct key *u_keyring,
  98                           const struct keyring_index_key *index_key);
  99extern int __key_link_begin(struct key *keyring,
 100                            const struct keyring_index_key *index_key,
 101                            struct assoc_array_edit **_edit);
 102extern int __key_link_check_live_key(struct key *keyring, struct key *key);
 103extern void __key_link(struct key *keyring, struct key *key,
 104                       struct assoc_array_edit **_edit);
 105extern void __key_link_end(struct key *keyring,
 106                           const struct keyring_index_key *index_key,
 107                           struct assoc_array_edit *edit);
 108
 109extern key_ref_t find_key_to_update(key_ref_t keyring_ref,
 110                                    const struct keyring_index_key *index_key);
 111
 112extern struct key *keyring_search_instkey(struct key *keyring,
 113                                          key_serial_t target_id);
 114
 115extern int iterate_over_keyring(const struct key *keyring,
 116                                int (*func)(const struct key *key, void *data),
 117                                void *data);
 118
 119struct keyring_search_context {
 120        struct keyring_index_key index_key;
 121        const struct cred       *cred;
 122        struct key_match_data   match_data;
 123        unsigned                flags;
 124#define KEYRING_SEARCH_NO_STATE_CHECK   0x0001  /* Skip state checks */
 125#define KEYRING_SEARCH_DO_STATE_CHECK   0x0002  /* Override NO_STATE_CHECK */
 126#define KEYRING_SEARCH_NO_UPDATE_TIME   0x0004  /* Don't update times */
 127#define KEYRING_SEARCH_NO_CHECK_PERM    0x0008  /* Don't check permissions */
 128#define KEYRING_SEARCH_DETECT_TOO_DEEP  0x0010  /* Give an error on excessive depth */
 129#define KEYRING_SEARCH_SKIP_EXPIRED     0x0020  /* Ignore expired keys (intention to replace) */
 130#define KEYRING_SEARCH_RECURSE          0x0040  /* Search child keyrings also */
 131
 132        int (*iterator)(const void *object, void *iterator_data);
 133
 134        /* Internal stuff */
 135        int                     skipped_ret;
 136        bool                    possessed;
 137        key_ref_t               result;
 138        time64_t                now;
 139};
 140
 141extern bool key_default_cmp(const struct key *key,
 142                            const struct key_match_data *match_data);
 143extern key_ref_t keyring_search_rcu(key_ref_t keyring_ref,
 144                                    struct keyring_search_context *ctx);
 145
 146extern key_ref_t search_cred_keyrings_rcu(struct keyring_search_context *ctx);
 147extern key_ref_t search_process_keyrings_rcu(struct keyring_search_context *ctx);
 148
 149extern struct key *find_keyring_by_name(const char *name, bool uid_keyring);
 150
 151extern int look_up_user_keyrings(struct key **, struct key **);
 152extern struct key *get_user_session_keyring_rcu(const struct cred *);
 153extern int install_thread_keyring_to_cred(struct cred *);
 154extern int install_process_keyring_to_cred(struct cred *);
 155extern int install_session_keyring_to_cred(struct cred *, struct key *);
 156
 157extern struct key *request_key_and_link(struct key_type *type,
 158                                        const char *description,
 159                                        struct key_tag *domain_tag,
 160                                        const void *callout_info,
 161                                        size_t callout_len,
 162                                        void *aux,
 163                                        struct key *dest_keyring,
 164                                        unsigned long flags);
 165
 166extern bool lookup_user_key_possessed(const struct key *key,
 167                                      const struct key_match_data *match_data);
 168#define KEY_LOOKUP_CREATE       0x01
 169#define KEY_LOOKUP_PARTIAL      0x02
 170
 171extern long join_session_keyring(const char *name);
 172extern void key_change_session_keyring(struct callback_head *twork);
 173
 174extern struct work_struct key_gc_work;
 175extern unsigned key_gc_delay;
 176extern void keyring_gc(struct key *keyring, time64_t limit);
 177extern void keyring_restriction_gc(struct key *keyring,
 178                                   struct key_type *dead_type);
 179extern void key_schedule_gc(time64_t gc_at);
 180extern void key_schedule_gc_links(void);
 181extern void key_gc_keytype(struct key_type *ktype);
 182
 183extern int key_task_permission(const key_ref_t key_ref,
 184                               const struct cred *cred,
 185                               enum key_need_perm need_perm);
 186
 187static inline void notify_key(struct key *key,
 188                              enum key_notification_subtype subtype, u32 aux)
 189{
 190#ifdef CONFIG_KEY_NOTIFICATIONS
 191        struct key_notification n = {
 192                .watch.type     = WATCH_TYPE_KEY_NOTIFY,
 193                .watch.subtype  = subtype,
 194                .watch.info     = watch_sizeof(n),
 195                .key_id         = key_serial(key),
 196                .aux            = aux,
 197        };
 198
 199        post_watch_notification(key->watchers, &n.watch, current_cred(),
 200                                n.key_id);
 201#endif
 202}
 203
 204/*
 205 * Check to see whether permission is granted to use a key in the desired way.
 206 */
 207static inline int key_permission(const key_ref_t key_ref,
 208                                 enum key_need_perm need_perm)
 209{
 210        return key_task_permission(key_ref, current_cred(), need_perm);
 211}
 212
 213extern struct key_type key_type_request_key_auth;
 214extern struct key *request_key_auth_new(struct key *target,
 215                                        const char *op,
 216                                        const void *callout_info,
 217                                        size_t callout_len,
 218                                        struct key *dest_keyring);
 219
 220extern struct key *key_get_instantiation_authkey(key_serial_t target_id);
 221
 222/*
 223 * Determine whether a key is dead.
 224 */
 225static inline bool key_is_dead(const struct key *key, time64_t limit)
 226{
 227        return
 228                key->flags & ((1 << KEY_FLAG_DEAD) |
 229                              (1 << KEY_FLAG_INVALIDATED)) ||
 230                (key->expiry > 0 && key->expiry <= limit) ||
 231                key->domain_tag->removed;
 232}
 233
 234/*
 235 * keyctl() functions
 236 */
 237extern long keyctl_get_keyring_ID(key_serial_t, int);
 238extern long keyctl_join_session_keyring(const char __user *);
 239extern long keyctl_update_key(key_serial_t, const void __user *, size_t);
 240extern long keyctl_revoke_key(key_serial_t);
 241extern long keyctl_keyring_clear(key_serial_t);
 242extern long keyctl_keyring_link(key_serial_t, key_serial_t);
 243extern long keyctl_keyring_move(key_serial_t, key_serial_t, key_serial_t, unsigned int);
 244extern long keyctl_keyring_unlink(key_serial_t, key_serial_t);
 245extern long keyctl_describe_key(key_serial_t, char __user *, size_t);
 246extern long keyctl_keyring_search(key_serial_t, const char __user *,
 247                                  const char __user *, key_serial_t);
 248extern long keyctl_read_key(key_serial_t, char __user *, size_t);
 249extern long keyctl_chown_key(key_serial_t, uid_t, gid_t);
 250extern long keyctl_setperm_key(key_serial_t, key_perm_t);
 251extern long keyctl_instantiate_key(key_serial_t, const void __user *,
 252                                   size_t, key_serial_t);
 253extern long keyctl_negate_key(key_serial_t, unsigned, key_serial_t);
 254extern long keyctl_set_reqkey_keyring(int);
 255extern long keyctl_set_timeout(key_serial_t, unsigned);
 256extern long keyctl_assume_authority(key_serial_t);
 257extern long keyctl_get_security(key_serial_t keyid, char __user *buffer,
 258                                size_t buflen);
 259extern long keyctl_session_to_parent(void);
 260extern long keyctl_reject_key(key_serial_t, unsigned, unsigned, key_serial_t);
 261extern long keyctl_instantiate_key_iov(key_serial_t,
 262                                       const struct iovec __user *,
 263                                       unsigned, key_serial_t);
 264extern long keyctl_invalidate_key(key_serial_t);
 265extern long keyctl_restrict_keyring(key_serial_t id,
 266                                    const char __user *_type,
 267                                    const char __user *_restriction);
 268#ifdef CONFIG_PERSISTENT_KEYRINGS
 269extern long keyctl_get_persistent(uid_t, key_serial_t);
 270extern unsigned persistent_keyring_expiry;
 271#else
 272static inline long keyctl_get_persistent(uid_t uid, key_serial_t destring)
 273{
 274        return -EOPNOTSUPP;
 275}
 276#endif
 277
 278#ifdef CONFIG_KEY_DH_OPERATIONS
 279extern long keyctl_dh_compute(struct keyctl_dh_params __user *, char __user *,
 280                              size_t, struct keyctl_kdf_params __user *);
 281extern long __keyctl_dh_compute(struct keyctl_dh_params __user *, char __user *,
 282                                size_t, struct keyctl_kdf_params *);
 283#ifdef CONFIG_COMPAT
 284extern long compat_keyctl_dh_compute(struct keyctl_dh_params __user *params,
 285                                char __user *buffer, size_t buflen,
 286                                struct compat_keyctl_kdf_params __user *kdf);
 287#endif
 288#define KEYCTL_KDF_MAX_OUTPUT_LEN       1024    /* max length of KDF output */
 289#define KEYCTL_KDF_MAX_OI_LEN           64      /* max length of otherinfo */
 290#else
 291static inline long keyctl_dh_compute(struct keyctl_dh_params __user *params,
 292                                     char __user *buffer, size_t buflen,
 293                                     struct keyctl_kdf_params __user *kdf)
 294{
 295        return -EOPNOTSUPP;
 296}
 297
 298#ifdef CONFIG_COMPAT
 299static inline long compat_keyctl_dh_compute(
 300                                struct keyctl_dh_params __user *params,
 301                                char __user *buffer, size_t buflen,
 302                                struct keyctl_kdf_params __user *kdf)
 303{
 304        return -EOPNOTSUPP;
 305}
 306#endif
 307#endif
 308
 309#ifdef CONFIG_ASYMMETRIC_KEY_TYPE
 310extern long keyctl_pkey_query(key_serial_t,
 311                              const char __user *,
 312                              struct keyctl_pkey_query __user *);
 313
 314extern long keyctl_pkey_verify(const struct keyctl_pkey_params __user *,
 315                               const char __user *,
 316                               const void __user *, const void __user *);
 317
 318extern long keyctl_pkey_e_d_s(int,
 319                              const struct keyctl_pkey_params __user *,
 320                              const char __user *,
 321                              const void __user *, void __user *);
 322#else
 323static inline long keyctl_pkey_query(key_serial_t id,
 324                                     const char __user *_info,
 325                                     struct keyctl_pkey_query __user *_res)
 326{
 327        return -EOPNOTSUPP;
 328}
 329
 330static inline long keyctl_pkey_verify(const struct keyctl_pkey_params __user *params,
 331                                      const char __user *_info,
 332                                      const void __user *_in,
 333                                      const void __user *_in2)
 334{
 335        return -EOPNOTSUPP;
 336}
 337
 338static inline long keyctl_pkey_e_d_s(int op,
 339                                     const struct keyctl_pkey_params __user *params,
 340                                     const char __user *_info,
 341                                     const void __user *_in,
 342                                     void __user *_out)
 343{
 344        return -EOPNOTSUPP;
 345}
 346#endif
 347
 348extern long keyctl_capabilities(unsigned char __user *_buffer, size_t buflen);
 349
 350#ifdef CONFIG_KEY_NOTIFICATIONS
 351extern long keyctl_watch_key(key_serial_t, int, int);
 352#else
 353static inline long keyctl_watch_key(key_serial_t key_id, int watch_fd, int watch_id)
 354{
 355        return -EOPNOTSUPP;
 356}
 357#endif
 358
 359/*
 360 * Debugging key validation
 361 */
 362#ifdef KEY_DEBUGGING
 363extern void __key_check(const struct key *);
 364
 365static inline void key_check(const struct key *key)
 366{
 367        if (key && (IS_ERR(key) || key->magic != KEY_DEBUG_MAGIC))
 368                __key_check(key);
 369}
 370
 371#else
 372
 373#define key_check(key) do {} while(0)
 374
 375#endif
 376#endif /* _INTERNAL_H */
 377