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/compat.h>
  19
  20struct 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
  38extern struct key_type key_type_dead;
  39extern struct key_type key_type_user;
  40extern 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 */
  51struct 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
  63extern struct rb_root   key_user_tree;
  64extern spinlock_t       key_user_lock;
  65extern struct key_user  root_key_user;
  66
  67extern struct key_user *key_user_lookup(kuid_t uid);
  68extern 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 */
  74extern unsigned key_quota_root_maxkeys;
  75extern unsigned key_quota_root_maxbytes;
  76extern unsigned key_quota_maxkeys;
  77extern unsigned key_quota_maxbytes;
  78
  79#define KEYQUOTA_LINK_BYTES     4               /* a link in a keyring is worth 4 bytes */
  80
  81
  82extern struct kmem_cache *key_jar;
  83extern struct rb_root key_serial_tree;
  84extern spinlock_t key_serial_lock;
  85extern struct mutex key_construction_mutex;
  86extern wait_queue_head_t request_key_conswq;
  87
  88extern void key_set_index_key(struct keyring_index_key *index_key);
  89extern struct key_type *key_type_lookup(const char *type);
  90extern void key_type_put(struct key_type *ktype);
  91
  92extern int __key_link_lock(struct key *keyring,
  93                           const struct keyring_index_key *index_key);
  94extern int __key_move_lock(struct key *l_keyring, struct key *u_keyring,
  95                           const struct keyring_index_key *index_key);
  96extern int __key_link_begin(struct key *keyring,
  97                            const struct keyring_index_key *index_key,
  98                            struct assoc_array_edit **_edit);
  99extern int __key_link_check_live_key(struct key *keyring, struct key *key);
 100extern void __key_link(struct key *key, struct assoc_array_edit **_edit);
 101extern void __key_link_end(struct key *keyring,
 102                           const struct keyring_index_key *index_key,
 103                           struct assoc_array_edit *edit);
 104
 105extern key_ref_t find_key_to_update(key_ref_t keyring_ref,
 106                                    const struct keyring_index_key *index_key);
 107
 108extern struct key *keyring_search_instkey(struct key *keyring,
 109                                          key_serial_t target_id);
 110
 111extern int iterate_over_keyring(const struct key *keyring,
 112                                int (*func)(const struct key *key, void *data),
 113                                void *data);
 114
 115struct 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
 137extern bool key_default_cmp(const struct key *key,
 138                            const struct key_match_data *match_data);
 139extern key_ref_t keyring_search_rcu(key_ref_t keyring_ref,
 140                                    struct keyring_search_context *ctx);
 141
 142extern key_ref_t search_cred_keyrings_rcu(struct keyring_search_context *ctx);
 143extern key_ref_t search_process_keyrings_rcu(struct keyring_search_context *ctx);
 144
 145extern struct key *find_keyring_by_name(const char *name, bool uid_keyring);
 146
 147extern int look_up_user_keyrings(struct key **, struct key **);
 148extern struct key *get_user_session_keyring_rcu(const struct cred *);
 149extern int install_thread_keyring_to_cred(struct cred *);
 150extern int install_process_keyring_to_cred(struct cred *);
 151extern int install_session_keyring_to_cred(struct cred *, struct key *);
 152
 153extern 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
 162extern 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
 168extern long join_session_keyring(const char *name);
 169extern void key_change_session_keyring(struct callback_head *twork);
 170
 171extern struct work_struct key_gc_work;
 172extern unsigned key_gc_delay;
 173extern void keyring_gc(struct key *keyring, time64_t limit);
 174extern void keyring_restriction_gc(struct key *keyring,
 175                                   struct key_type *dead_type);
 176extern void key_schedule_gc(time64_t gc_at);
 177extern void key_schedule_gc_links(void);
 178extern void key_gc_keytype(struct key_type *ktype);
 179
 180extern 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 */
 187static 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
 192extern struct key_type key_type_request_key_auth;
 193extern 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
 199extern struct key *key_get_instantiation_authkey(key_serial_t target_id);
 200
 201/*
 202 * Determine whether a key is dead.
 203 */
 204static 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 */
 216extern long keyctl_get_keyring_ID(key_serial_t, int);
 217extern long keyctl_join_session_keyring(const char __user *);
 218extern long keyctl_update_key(key_serial_t, const void __user *, size_t);
 219extern long keyctl_revoke_key(key_serial_t);
 220extern long keyctl_keyring_clear(key_serial_t);
 221extern long keyctl_keyring_link(key_serial_t, key_serial_t);
 222extern long keyctl_keyring_move(key_serial_t, key_serial_t, key_serial_t, unsigned int);
 223extern long keyctl_keyring_unlink(key_serial_t, key_serial_t);
 224extern long keyctl_describe_key(key_serial_t, char __user *, size_t);
 225extern long keyctl_keyring_search(key_serial_t, const char __user *,
 226                                  const char __user *, key_serial_t);
 227extern long keyctl_read_key(key_serial_t, char __user *, size_t);
 228extern long keyctl_chown_key(key_serial_t, uid_t, gid_t);
 229extern long keyctl_setperm_key(key_serial_t, key_perm_t);
 230extern long keyctl_instantiate_key(key_serial_t, const void __user *,
 231                                   size_t, key_serial_t);
 232extern long keyctl_negate_key(key_serial_t, unsigned, key_serial_t);
 233extern long keyctl_set_reqkey_keyring(int);
 234extern long keyctl_set_timeout(key_serial_t, unsigned);
 235extern long keyctl_assume_authority(key_serial_t);
 236extern long keyctl_get_security(key_serial_t keyid, char __user *buffer,
 237                                size_t buflen);
 238extern long keyctl_session_to_parent(void);
 239extern long keyctl_reject_key(key_serial_t, unsigned, unsigned, key_serial_t);
 240extern long keyctl_instantiate_key_iov(key_serial_t,
 241                                       const struct iovec __user *,
 242                                       unsigned, key_serial_t);
 243extern long keyctl_invalidate_key(key_serial_t);
 244
 245struct iov_iter;
 246extern long keyctl_instantiate_key_common(key_serial_t,
 247                                          struct iov_iter *,
 248                                          key_serial_t);
 249extern long keyctl_restrict_keyring(key_serial_t id,
 250                                    const char __user *_type,
 251                                    const char __user *_restriction);
 252#ifdef CONFIG_PERSISTENT_KEYRINGS
 253extern long keyctl_get_persistent(uid_t, key_serial_t);
 254extern unsigned persistent_keyring_expiry;
 255#else
 256static 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
 263extern long keyctl_dh_compute(struct keyctl_dh_params __user *, char __user *,
 264                              size_t, struct keyctl_kdf_params __user *);
 265extern long __keyctl_dh_compute(struct keyctl_dh_params __user *, char __user *,
 266                                size_t, struct keyctl_kdf_params *);
 267#ifdef CONFIG_COMPAT
 268extern 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
 275static 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
 283static 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
 294extern long keyctl_pkey_query(key_serial_t,
 295                              const char __user *,
 296                              struct keyctl_pkey_query __user *);
 297
 298extern long keyctl_pkey_verify(const struct keyctl_pkey_params __user *,
 299                               const char __user *,
 300                               const void __user *, const void __user *);
 301
 302extern 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
 307static 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
 314static 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
 322static 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
 332extern long keyctl_capabilities(unsigned char __user *_buffer, size_t buflen);
 333
 334/*
 335 * Debugging key validation
 336 */
 337#ifdef KEY_DEBUGGING
 338extern void __key_check(const struct key *);
 339
 340static 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 */
 353