security/keys/internal.h

   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
  23 struct 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
  41 extern struct key_type key_type_dead;
  42 extern struct key_type key_type_user;
  43 extern 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  */
  54 struct 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
  66 extern struct rb_root   key_user_tree;
  67 extern spinlock_t       key_user_lock;
  68 extern struct key_user  root_key_user;
  69
  70 extern struct key_user *key_user_lookup(kuid_t uid);
  71 extern 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  */
  77 extern unsigned key_quota_root_maxkeys;
  78 extern unsigned key_quota_root_maxbytes;
  79 extern unsigned key_quota_maxkeys;
  80 extern unsigned key_quota_maxbytes;
  81
  82 #define KEYQUOTA_LINK_BYTES     4               /* a link in a keyring is worth 4 bytes */
  83
  84
  85 extern struct kmem_cache *key_jar;
  86 extern struct rb_root key_serial_tree;
  87 extern spinlock_t key_serial_lock;
  88 extern struct mutex key_construction_mutex;
  89 extern wait_queue_head_t request_key_conswq;
  90
  91 extern void key_set_index_key(struct keyring_index_key *index_key);
  92 extern struct key_type *key_type_lookup(const char *type);
  93 extern void key_type_put(struct key_type *ktype);
  94
  95 extern int __key_link_lock(struct key *keyring,
  96                            const struct keyring_index_key *index_key);
  97 extern int __key_move_lock(struct key *l_keyring, struct key *u_keyring,
  98                            const struct keyring_index_key *index_key);
  99 extern int __key_link_begin(struct key *keyring,
 100                             const struct keyring_index_key *index_key,
 101                             struct assoc_array_edit **_edit);
 102 extern int __key_link_check_live_key(struct key *keyring, struct key *key);
 103 extern void __key_link(struct key *keyring, struct key *key,
 104                        struct assoc_array_edit **_edit);
 105 extern void __key_link_end(struct key *keyring,
 106                            const struct keyring_index_key *index_key,
 107                            struct assoc_array_edit *edit);
 108
 109 extern key_ref_t find_key_to_update(key_ref_t keyring_ref,
 110                                     const struct keyring_index_key *index_key);
 111
 112 struct keyring_search_context {
 113         struct keyring_index_key index_key;
 114         const struct cred       *cred;
 115         struct key_match_data   match_data;
 116         unsigned                flags;
 117 #define KEYRING_SEARCH_NO_STATE_CHECK   0x0001  /* Skip state checks */
 118 #define KEYRING_SEARCH_DO_STATE_CHECK   0x0002  /* Override NO_STATE_CHECK */
 119 #define KEYRING_SEARCH_NO_UPDATE_TIME   0x0004  /* Don't update times */
 120 #define KEYRING_SEARCH_NO_CHECK_PERM    0x0008  /* Don't check permissions */
 121 #define KEYRING_SEARCH_DETECT_TOO_DEEP  0x0010  /* Give an error on excessive depth */
 122 #define KEYRING_SEARCH_SKIP_EXPIRED     0x0020  /* Ignore expired keys (intention to replace) */
 123 #define KEYRING_SEARCH_RECURSE          0x0040  /* Search child keyrings also */
 124
 125         int (*iterator)(const void *object, void *iterator_data);
 126
 127         /* Internal stuff */
 128         int                     skipped_ret;
 129         bool                    possessed;
 130         key_ref_t               result;
 131         time64_t                now;
 132 };
 133
 134 extern bool key_default_cmp(const struct key *key,
 135                             const struct key_match_data *match_data);
 136 extern key_ref_t keyring_search_rcu(key_ref_t keyring_ref,
 137                                     struct keyring_search_context *ctx);
 138
 139 extern key_ref_t search_cred_keyrings_rcu(struct keyring_search_context *ctx);
 140 extern key_ref_t search_process_keyrings_rcu(struct keyring_search_context *ctx);
 141
 142 extern struct key *find_keyring_by_name(const char *name, bool uid_keyring);
 143
 144 extern int look_up_user_keyrings(struct key **, struct key **);
 145 extern struct key *get_user_session_keyring_rcu(const struct cred *);
 146 extern int install_thread_keyring_to_cred(struct cred *);
 147 extern int install_process_keyring_to_cred(struct cred *);
 148 extern int install_session_keyring_to_cred(struct cred *, struct key *);
 149
 150 extern struct key *request_key_and_link(struct key_type *type,
 151                                         const char *description,
 152                                         struct key_tag *domain_tag,
 153                                         const void *callout_info,
 154                                         size_t callout_len,
 155                                         void *aux,
 156                                         struct key *dest_keyring,
 157                                         unsigned long flags);
 158
 159 extern bool lookup_user_key_possessed(const struct key *key,
 160                                       const struct key_match_data *match_data);
 161
 162 extern long join_session_keyring(const char *name);
 163 extern void key_change_session_keyring(struct callback_head *twork);
 164
 165 extern struct work_struct key_gc_work;
 166 extern unsigned key_gc_delay;
 167 extern void keyring_gc(struct key *keyring, time64_t limit);
 168 extern void keyring_restriction_gc(struct key *keyring,
 169                                    struct key_type *dead_type);
 170 void key_set_expiry(struct key *key, time64_t expiry);
 171 extern void key_schedule_gc(time64_t gc_at);
 172 extern void key_schedule_gc_links(void);
 173 extern void key_gc_keytype(struct key_type *ktype);
 174
 175 extern int key_task_permission(const key_ref_t key_ref,
 176                                const struct cred *cred,
 177                                enum key_need_perm need_perm);
 178
 179 static inline void notify_key(struct key *key,
 180                               enum key_notification_subtype subtype, u32 aux)
 181 {
 182 #ifdef CONFIG_KEY_NOTIFICATIONS
 183         struct key_notification n = {
 184                 .watch.type     = WATCH_TYPE_KEY_NOTIFY,
 185                 .watch.subtype  = subtype,
 186                 .watch.info     = watch_sizeof(n),
 187                 .key_id         = key_serial(key),
 188                 .aux            = aux,
 189         };
 190
 191         post_watch_notification(key->watchers, &n.watch, current_cred(),
 192                                 n.key_id);
 193 #endif
 194 }
 195
 196 /*
 197  * Check to see whether permission is granted to use a key in the desired way.
 198  */
 199 static inline int key_permission(const key_ref_t key_ref,
 200                                  enum key_need_perm need_perm)
 201 {
 202         return key_task_permission(key_ref, current_cred(), need_perm);
 203 }
 204
 205 extern struct key_type key_type_request_key_auth;
 206 extern struct key *request_key_auth_new(struct key *target,
 207                                         const char *op,
 208                                         const void *callout_info,
 209                                         size_t callout_len,
 210                                         struct key *dest_keyring);
 211
 212 extern struct key *key_get_instantiation_authkey(key_serial_t target_id);
 213
 214 /*
 215  * Determine whether a key is dead.
 216  */
 217 static inline bool key_is_dead(const struct key *key, time64_t limit)
 218 {
 219         time64_t expiry = key->expiry;
 220
 221         if (expiry != TIME64_MAX) {
 222                 if (!(key->type->flags & KEY_TYPE_INSTANT_REAP))
 223                         expiry += key_gc_delay;
 224                 if (expiry <= limit)
 225                         return true;
 226         }
 227
 228         return
 229                 key->flags & ((1 << KEY_FLAG_DEAD) |
 230                               (1 << KEY_FLAG_INVALIDATED)) ||
 231                 key->domain_tag->removed;
 232 }
 233
 234 /*
 235  * keyctl() functions
 236  */
 237 extern long keyctl_get_keyring_ID(key_serial_t, int);
 238 extern long keyctl_join_session_keyring(const char __user *);
 239 extern long keyctl_update_key(key_serial_t, const void __user *, size_t);
 240 extern long keyctl_revoke_key(key_serial_t);
 241 extern long keyctl_keyring_clear(key_serial_t);
 242 extern long keyctl_keyring_link(key_serial_t, key_serial_t);
 243 extern long keyctl_keyring_move(key_serial_t, key_serial_t, key_serial_t, unsigned int);
 244 extern long keyctl_keyring_unlink(key_serial_t, key_serial_t);
 245 extern long keyctl_describe_key(key_serial_t, char __user *, size_t);
 246 extern long keyctl_keyring_search(key_serial_t, const char __user *,
 247                                   const char __user *, key_serial_t);
 248 extern long keyctl_read_key(key_serial_t, char __user *, size_t);
 249 extern long keyctl_chown_key(key_serial_t, uid_t, gid_t);
 250 extern long keyctl_setperm_key(key_serial_t, key_perm_t);
 251 extern long keyctl_instantiate_key(key_serial_t, const void __user *,
 252                                    size_t, key_serial_t);
 253 extern long keyctl_negate_key(key_serial_t, unsigned, key_serial_t);
 254 extern long keyctl_set_reqkey_keyring(int);
 255 extern long keyctl_set_timeout(key_serial_t, unsigned);
 256 extern long keyctl_assume_authority(key_serial_t);
 257 extern long keyctl_get_security(key_serial_t keyid, char __user *buffer,
 258                                 size_t buflen);
 259 extern long keyctl_session_to_parent(void);
 260 extern long keyctl_reject_key(key_serial_t, unsigned, unsigned, key_serial_t);
 261 extern long keyctl_instantiate_key_iov(key_serial_t,
 262                                        const struct iovec __user *,
 263                                        unsigned, key_serial_t);
 264 extern long keyctl_invalidate_key(key_serial_t);
 265 extern long keyctl_restrict_keyring(key_serial_t id,
 266                                     const char __user *_type,
 267                                     const char __user *_restriction);
 268 #ifdef CONFIG_PERSISTENT_KEYRINGS
 269 extern long keyctl_get_persistent(uid_t, key_serial_t);
 270 extern unsigned persistent_keyring_expiry;
 271 #else
 272 static 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
 279 extern long keyctl_dh_compute(struct keyctl_dh_params __user *, char __user *,
 280                               size_t, struct keyctl_kdf_params __user *);
 281 extern long __keyctl_dh_compute(struct keyctl_dh_params __user *, char __user *,
 282                                 size_t, struct keyctl_kdf_params *);
 283 #ifdef CONFIG_COMPAT
 284 extern 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
 291 static 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
 299 static 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
 310 extern long keyctl_pkey_query(key_serial_t,
 311                               const char __user *,
 312                               struct keyctl_pkey_query __user *);
 313
 314 extern long keyctl_pkey_verify(const struct keyctl_pkey_params __user *,
 315                                const char __user *,
 316                                const void __user *, const void __user *);
 317
 318 extern 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
 323 static 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
 330 static 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
 338 static 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
 348 extern long keyctl_capabilities(unsigned char __user *_buffer, size_t buflen);
 349
 350 #ifdef CONFIG_KEY_NOTIFICATIONS
 351 extern long keyctl_watch_key(key_serial_t, int, int);
 352 #else
 353 static 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
 363 extern void __key_check(const struct key *);
 364
 365 static 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 */