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/compat.h>
  19
  20 struct iovec;
  21
  22 #ifdef __KDEBUG
  23 #define kenter(FMT, ...) \
  24         printk(KERN_DEBUG "==> %s("FMT")\n", __func__, ##__VA_ARGS__)
  25 #define kleave(FMT, ...) \
  26         printk(KERN_DEBUG "<== %s()"FMT"\n", __func__, ##__VA_ARGS__)
  27 #define kdebug(FMT, ...) \
  28         printk(KERN_DEBUG "   "FMT"\n", ##__VA_ARGS__)
  29 #else
  30 #define kenter(FMT, ...) \
  31         no_printk(KERN_DEBUG "==> %s("FMT")\n", __func__, ##__VA_ARGS__)
  32 #define kleave(FMT, ...) \
  33         no_printk(KERN_DEBUG "<== %s()"FMT"\n", __func__, ##__VA_ARGS__)
  34 #define kdebug(FMT, ...) \
  35         no_printk(KERN_DEBUG FMT"\n", ##__VA_ARGS__)
  36 #endif
  37
  38 extern struct key_type key_type_dead;
  39 extern struct key_type key_type_user;
  40 extern struct key_type key_type_logon;
  41
  42 /*****************************************************************************/
  43 /*
  44  * Keep track of keys for a user.
  45  *
  46  * This needs to be separate to user_struct to avoid a refcount-loop
  47  * (user_struct pins some keyrings which pin this struct).
  48  *
  49  * We also keep track of keys under request from userspace for this UID here.
  50  */
  51 struct key_user {
  52         struct rb_node          node;
  53         struct mutex            cons_lock;      /* construction initiation lock */
  54         spinlock_t              lock;
  55         refcount_t              usage;          /* for accessing qnkeys & qnbytes */
  56         atomic_t                nkeys;          /* number of keys */
  57         atomic_t                nikeys;         /* number of instantiated keys */
  58         kuid_t                  uid;
  59         int                     qnkeys;         /* number of keys allocated to this user */
  60         int                     qnbytes;        /* number of bytes allocated to this user */
  61 };
  62
  63 extern struct rb_root   key_user_tree;
  64 extern spinlock_t       key_user_lock;
  65 extern struct key_user  root_key_user;
  66
  67 extern struct key_user *key_user_lookup(kuid_t uid);
  68 extern void key_user_put(struct key_user *user);
  69
  70 /*
  71  * Key quota limits.
  72  * - root has its own separate limits to everyone else
  73  */
  74 extern unsigned key_quota_root_maxkeys;
  75 extern unsigned key_quota_root_maxbytes;
  76 extern unsigned key_quota_maxkeys;
  77 extern unsigned key_quota_maxbytes;
  78
  79 #define KEYQUOTA_LINK_BYTES     4               /* a link in a keyring is worth 4 bytes */
  80
  81
  82 extern struct kmem_cache *key_jar;
  83 extern struct rb_root key_serial_tree;
  84 extern spinlock_t key_serial_lock;
  85 extern struct mutex key_construction_mutex;
  86 extern wait_queue_head_t request_key_conswq;
  87
  88 extern void key_set_index_key(struct keyring_index_key *index_key);
  89 extern struct key_type *key_type_lookup(const char *type);
  90 extern void key_type_put(struct key_type *ktype);
  91
  92 extern int __key_link_lock(struct key *keyring,
  93                            const struct keyring_index_key *index_key);
  94 extern int __key_move_lock(struct key *l_keyring, struct key *u_keyring,
  95                            const struct keyring_index_key *index_key);
  96 extern int __key_link_begin(struct key *keyring,
  97                             const struct keyring_index_key *index_key,
  98                             struct assoc_array_edit **_edit);
  99 extern int __key_link_check_live_key(struct key *keyring, struct key *key);
 100 extern void __key_link(struct key *key, struct assoc_array_edit **_edit);
 101 extern void __key_link_end(struct key *keyring,
 102                            const struct keyring_index_key *index_key,
 103                            struct assoc_array_edit *edit);
 104
 105 extern key_ref_t find_key_to_update(key_ref_t keyring_ref,
 106                                     const struct keyring_index_key *index_key);
 107
 108 extern struct key *keyring_search_instkey(struct key *keyring,
 109                                           key_serial_t target_id);
 110
 111 extern int iterate_over_keyring(const struct key *keyring,
 112                                 int (*func)(const struct key *key, void *data),
 113                                 void *data);
 114
 115 struct keyring_search_context {
 116         struct keyring_index_key index_key;
 117         const struct cred       *cred;
 118         struct key_match_data   match_data;
 119         unsigned                flags;
 120 #define KEYRING_SEARCH_NO_STATE_CHECK   0x0001  /* Skip state checks */
 121 #define KEYRING_SEARCH_DO_STATE_CHECK   0x0002  /* Override NO_STATE_CHECK */
 122 #define KEYRING_SEARCH_NO_UPDATE_TIME   0x0004  /* Don't update times */
 123 #define KEYRING_SEARCH_NO_CHECK_PERM    0x0008  /* Don't check permissions */
 124 #define KEYRING_SEARCH_DETECT_TOO_DEEP  0x0010  /* Give an error on excessive depth */
 125 #define KEYRING_SEARCH_SKIP_EXPIRED     0x0020  /* Ignore expired keys (intention to replace) */
 126 #define KEYRING_SEARCH_RECURSE          0x0040  /* Search child keyrings also */
 127
 128         int (*iterator)(const void *object, void *iterator_data);
 129
 130         /* Internal stuff */
 131         int                     skipped_ret;
 132         bool                    possessed;
 133         key_ref_t               result;
 134         time64_t                now;
 135 };
 136
 137 extern bool key_default_cmp(const struct key *key,
 138                             const struct key_match_data *match_data);
 139 extern key_ref_t keyring_search_rcu(key_ref_t keyring_ref,
 140                                     struct keyring_search_context *ctx);
 141
 142 extern key_ref_t search_cred_keyrings_rcu(struct keyring_search_context *ctx);
 143 extern key_ref_t search_process_keyrings_rcu(struct keyring_search_context *ctx);
 144
 145 extern struct key *find_keyring_by_name(const char *name, bool uid_keyring);
 146
 147 extern int look_up_user_keyrings(struct key **, struct key **);
 148 extern struct key *get_user_session_keyring_rcu(const struct cred *);
 149 extern int install_thread_keyring_to_cred(struct cred *);
 150 extern int install_process_keyring_to_cred(struct cred *);
 151 extern int install_session_keyring_to_cred(struct cred *, struct key *);
 152
 153 extern struct key *request_key_and_link(struct key_type *type,
 154                                         const char *description,
 155                                         struct key_tag *domain_tag,
 156                                         const void *callout_info,
 157                                         size_t callout_len,
 158                                         void *aux,
 159                                         struct key *dest_keyring,
 160                                         unsigned long flags);
 161
 162 extern bool lookup_user_key_possessed(const struct key *key,
 163                                       const struct key_match_data *match_data);
 164 #define KEY_LOOKUP_CREATE       0x01
 165 #define KEY_LOOKUP_PARTIAL      0x02
 166 #define KEY_LOOKUP_FOR_UNLINK   0x04
 167
 168 extern long join_session_keyring(const char *name);
 169 extern void key_change_session_keyring(struct callback_head *twork);
 170
 171 extern struct work_struct key_gc_work;
 172 extern unsigned key_gc_delay;
 173 extern void keyring_gc(struct key *keyring, time64_t limit);
 174 extern void keyring_restriction_gc(struct key *keyring,
 175                                    struct key_type *dead_type);
 176 extern void key_schedule_gc(time64_t gc_at);
 177 extern void key_schedule_gc_links(void);
 178 extern void key_gc_keytype(struct key_type *ktype);
 179
 180 extern int key_task_permission(const key_ref_t key_ref,
 181                                const struct cred *cred,
 182                                key_perm_t perm);
 183
 184 /*
 185  * Check to see whether permission is granted to use a key in the desired way.
 186  */
 187 static inline int key_permission(const key_ref_t key_ref, unsigned perm)
 188 {
 189         return key_task_permission(key_ref, current_cred(), perm);
 190 }
 191
 192 extern struct key_type key_type_request_key_auth;
 193 extern struct key *request_key_auth_new(struct key *target,
 194                                         const char *op,
 195                                         const void *callout_info,
 196                                         size_t callout_len,
 197                                         struct key *dest_keyring);
 198
 199 extern struct key *key_get_instantiation_authkey(key_serial_t target_id);
 200
 201 /*
 202  * Determine whether a key is dead.
 203  */
 204 static inline bool key_is_dead(const struct key *key, time64_t limit)
 205 {
 206         return
 207                 key->flags & ((1 << KEY_FLAG_DEAD) |
 208                               (1 << KEY_FLAG_INVALIDATED)) ||
 209                 (key->expiry > 0 && key->expiry <= limit) ||
 210                 key->domain_tag->removed;
 211 }
 212
 213 /*
 214  * keyctl() functions
 215  */
 216 extern long keyctl_get_keyring_ID(key_serial_t, int);
 217 extern long keyctl_join_session_keyring(const char __user *);
 218 extern long keyctl_update_key(key_serial_t, const void __user *, size_t);
 219 extern long keyctl_revoke_key(key_serial_t);
 220 extern long keyctl_keyring_clear(key_serial_t);
 221 extern long keyctl_keyring_link(key_serial_t, key_serial_t);
 222 extern long keyctl_keyring_move(key_serial_t, key_serial_t, key_serial_t, unsigned int);
 223 extern long keyctl_keyring_unlink(key_serial_t, key_serial_t);
 224 extern long keyctl_describe_key(key_serial_t, char __user *, size_t);
 225 extern long keyctl_keyring_search(key_serial_t, const char __user *,
 226                                   const char __user *, key_serial_t);
 227 extern long keyctl_read_key(key_serial_t, char __user *, size_t);
 228 extern long keyctl_chown_key(key_serial_t, uid_t, gid_t);
 229 extern long keyctl_setperm_key(key_serial_t, key_perm_t);
 230 extern long keyctl_instantiate_key(key_serial_t, const void __user *,
 231                                    size_t, key_serial_t);
 232 extern long keyctl_negate_key(key_serial_t, unsigned, key_serial_t);
 233 extern long keyctl_set_reqkey_keyring(int);
 234 extern long keyctl_set_timeout(key_serial_t, unsigned);
 235 extern long keyctl_assume_authority(key_serial_t);
 236 extern long keyctl_get_security(key_serial_t keyid, char __user *buffer,
 237                                 size_t buflen);
 238 extern long keyctl_session_to_parent(void);
 239 extern long keyctl_reject_key(key_serial_t, unsigned, unsigned, key_serial_t);
 240 extern long keyctl_instantiate_key_iov(key_serial_t,
 241                                        const struct iovec __user *,
 242                                        unsigned, key_serial_t);
 243 extern long keyctl_invalidate_key(key_serial_t);
 244
 245 struct iov_iter;
 246 extern long keyctl_instantiate_key_common(key_serial_t,
 247                                           struct iov_iter *,
 248                                           key_serial_t);
 249 extern long keyctl_restrict_keyring(key_serial_t id,
 250                                     const char __user *_type,
 251                                     const char __user *_restriction);
 252 #ifdef CONFIG_PERSISTENT_KEYRINGS
 253 extern long keyctl_get_persistent(uid_t, key_serial_t);
 254 extern unsigned persistent_keyring_expiry;
 255 #else
 256 static inline long keyctl_get_persistent(uid_t uid, key_serial_t destring)
 257 {
 258         return -EOPNOTSUPP;
 259 }
 260 #endif
 261
 262 #ifdef CONFIG_KEY_DH_OPERATIONS
 263 extern long keyctl_dh_compute(struct keyctl_dh_params __user *, char __user *,
 264                               size_t, struct keyctl_kdf_params __user *);
 265 extern long __keyctl_dh_compute(struct keyctl_dh_params __user *, char __user *,
 266                                 size_t, struct keyctl_kdf_params *);
 267 #ifdef CONFIG_COMPAT
 268 extern long compat_keyctl_dh_compute(struct keyctl_dh_params __user *params,
 269                                 char __user *buffer, size_t buflen,
 270                                 struct compat_keyctl_kdf_params __user *kdf);
 271 #endif
 272 #define KEYCTL_KDF_MAX_OUTPUT_LEN       1024    /* max length of KDF output */
 273 #define KEYCTL_KDF_MAX_OI_LEN           64      /* max length of otherinfo */
 274 #else
 275 static inline long keyctl_dh_compute(struct keyctl_dh_params __user *params,
 276                                      char __user *buffer, size_t buflen,
 277                                      struct keyctl_kdf_params __user *kdf)
 278 {
 279         return -EOPNOTSUPP;
 280 }
 281
 282 #ifdef CONFIG_COMPAT
 283 static inline long compat_keyctl_dh_compute(
 284                                 struct keyctl_dh_params __user *params,
 285                                 char __user *buffer, size_t buflen,
 286                                 struct keyctl_kdf_params __user *kdf)
 287 {
 288         return -EOPNOTSUPP;
 289 }
 290 #endif
 291 #endif
 292
 293 #ifdef CONFIG_ASYMMETRIC_KEY_TYPE
 294 extern long keyctl_pkey_query(key_serial_t,
 295                               const char __user *,
 296                               struct keyctl_pkey_query __user *);
 297
 298 extern long keyctl_pkey_verify(const struct keyctl_pkey_params __user *,
 299                                const char __user *,
 300                                const void __user *, const void __user *);
 301
 302 extern long keyctl_pkey_e_d_s(int,
 303                               const struct keyctl_pkey_params __user *,
 304                               const char __user *,
 305                               const void __user *, void __user *);
 306 #else
 307 static inline long keyctl_pkey_query(key_serial_t id,
 308                                      const char __user *_info,
 309                                      struct keyctl_pkey_query __user *_res)
 310 {
 311         return -EOPNOTSUPP;
 312 }
 313
 314 static inline long keyctl_pkey_verify(const struct keyctl_pkey_params __user *params,
 315                                       const char __user *_info,
 316                                       const void __user *_in,
 317                                       const void __user *_in2)
 318 {
 319         return -EOPNOTSUPP;
 320 }
 321
 322 static inline long keyctl_pkey_e_d_s(int op,
 323                                      const struct keyctl_pkey_params __user *params,
 324                                      const char __user *_info,
 325                                      const void __user *_in,
 326                                      void __user *_out)
 327 {
 328         return -EOPNOTSUPP;
 329 }
 330 #endif
 331
 332 extern long keyctl_capabilities(unsigned char __user *_buffer, size_t buflen);
 333
 334 /*
 335  * Debugging key validation
 336  */
 337 #ifdef KEY_DEBUGGING
 338 extern void __key_check(const struct key *);
 339
 340 static inline void key_check(const struct key *key)
 341 {
 342         if (key && (IS_ERR(key) || key->magic != KEY_DEBUG_MAGIC))
 343                 __key_check(key);
 344 }
 345
 346 #else
 347
 348 #define key_check(key) do {} while(0)
 349
 350 #endif
 351
 352 #endif /* _INTERNAL_H */