linux/security/keys/internal.h
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   1/* Authentication token and access key management internal defs
   2 *
   3 * Copyright (C) 2003-5, 2007 Red Hat, Inc. All Rights Reserved.
   4 * Written by David Howells (dhowells@redhat.com)
   5 *
   6 * This program is free software; you can redistribute it and/or
   7 * modify it under the terms of the GNU General Public License
   8 * as published by the Free Software Foundation; either version
   9 * 2 of the License, or (at your option) any later version.
  10 */
  11
  12#ifndef _INTERNAL_H
  13#define _INTERNAL_H
  14
  15#include <linux/sched.h>
  16#include <linux/wait_bit.h>
  17#include <linux/cred.h>
  18#include <linux/key-type.h>
  19#include <linux/task_work.h>
  20#include <linux/keyctl.h>
  21#include <linux/refcount.h>
  22#include <linux/compat.h>
  23
  24struct iovec;
  25
  26#ifdef __KDEBUG
  27#define kenter(FMT, ...) \
  28        printk(KERN_DEBUG "==> %s("FMT")\n", __func__, ##__VA_ARGS__)
  29#define kleave(FMT, ...) \
  30        printk(KERN_DEBUG "<== %s()"FMT"\n", __func__, ##__VA_ARGS__)
  31#define kdebug(FMT, ...) \
  32        printk(KERN_DEBUG "   "FMT"\n", ##__VA_ARGS__)
  33#else
  34#define kenter(FMT, ...) \
  35        no_printk(KERN_DEBUG "==> %s("FMT")\n", __func__, ##__VA_ARGS__)
  36#define kleave(FMT, ...) \
  37        no_printk(KERN_DEBUG "<== %s()"FMT"\n", __func__, ##__VA_ARGS__)
  38#define kdebug(FMT, ...) \
  39        no_printk(KERN_DEBUG FMT"\n", ##__VA_ARGS__)
  40#endif
  41
  42extern struct key_type key_type_dead;
  43extern struct key_type key_type_user;
  44extern struct key_type key_type_logon;
  45
  46/*****************************************************************************/
  47/*
  48 * Keep track of keys for a user.
  49 *
  50 * This needs to be separate to user_struct to avoid a refcount-loop
  51 * (user_struct pins some keyrings which pin this struct).
  52 *
  53 * We also keep track of keys under request from userspace for this UID here.
  54 */
  55struct key_user {
  56        struct rb_node          node;
  57        struct mutex            cons_lock;      /* construction initiation lock */
  58        spinlock_t              lock;
  59        refcount_t              usage;          /* for accessing qnkeys & qnbytes */
  60        atomic_t                nkeys;          /* number of keys */
  61        atomic_t                nikeys;         /* number of instantiated keys */
  62        kuid_t                  uid;
  63        int                     qnkeys;         /* number of keys allocated to this user */
  64        int                     qnbytes;        /* number of bytes allocated to this user */
  65};
  66
  67extern struct rb_root   key_user_tree;
  68extern spinlock_t       key_user_lock;
  69extern struct key_user  root_key_user;
  70
  71extern struct key_user *key_user_lookup(kuid_t uid);
  72extern void key_user_put(struct key_user *user);
  73
  74/*
  75 * Key quota limits.
  76 * - root has its own separate limits to everyone else
  77 */
  78extern unsigned key_quota_root_maxkeys;
  79extern unsigned key_quota_root_maxbytes;
  80extern unsigned key_quota_maxkeys;
  81extern unsigned key_quota_maxbytes;
  82
  83#define KEYQUOTA_LINK_BYTES     4               /* a link in a keyring is worth 4 bytes */
  84
  85
  86extern struct kmem_cache *key_jar;
  87extern struct rb_root key_serial_tree;
  88extern spinlock_t key_serial_lock;
  89extern struct mutex key_construction_mutex;
  90extern wait_queue_head_t request_key_conswq;
  91
  92
  93extern struct key_type *key_type_lookup(const char *type);
  94extern void key_type_put(struct key_type *ktype);
  95
  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
 127        int (*iterator)(const void *object, void *iterator_data);
 128
 129        /* Internal stuff */
 130        int                     skipped_ret;
 131        bool                    possessed;
 132        key_ref_t               result;
 133        time64_t                now;
 134};
 135
 136extern bool key_default_cmp(const struct key *key,
 137                            const struct key_match_data *match_data);
 138extern key_ref_t keyring_search_aux(key_ref_t keyring_ref,
 139                                    struct keyring_search_context *ctx);
 140
 141extern key_ref_t search_my_process_keyrings(struct keyring_search_context *ctx);
 142extern key_ref_t search_process_keyrings(struct keyring_search_context *ctx);
 143
 144extern struct key *find_keyring_by_name(const char *name, bool uid_keyring);
 145
 146extern int install_user_keyrings(void);
 147extern int install_thread_keyring_to_cred(struct cred *);
 148extern int install_process_keyring_to_cred(struct cred *);
 149extern int install_session_keyring_to_cred(struct cred *, struct key *);
 150
 151extern struct key *request_key_and_link(struct key_type *type,
 152                                        const char *description,
 153                                        const void *callout_info,
 154                                        size_t callout_len,
 155                                        void *aux,
 156                                        struct key *dest_keyring,
 157                                        unsigned long flags);
 158
 159extern bool lookup_user_key_possessed(const struct key *key,
 160                                      const struct key_match_data *match_data);
 161extern key_ref_t lookup_user_key(key_serial_t id, unsigned long flags,
 162                                 key_perm_t perm);
 163#define KEY_LOOKUP_CREATE       0x01
 164#define KEY_LOOKUP_PARTIAL      0x02
 165#define KEY_LOOKUP_FOR_UNLINK   0x04
 166
 167extern long join_session_keyring(const char *name);
 168extern void key_change_session_keyring(struct callback_head *twork);
 169
 170extern struct work_struct key_gc_work;
 171extern unsigned key_gc_delay;
 172extern void keyring_gc(struct key *keyring, time64_t limit);
 173extern void keyring_restriction_gc(struct key *keyring,
 174                                   struct key_type *dead_type);
 175extern void key_schedule_gc(time64_t gc_at);
 176extern void key_schedule_gc_links(void);
 177extern void key_gc_keytype(struct key_type *ktype);
 178
 179extern int key_task_permission(const key_ref_t key_ref,
 180                               const struct cred *cred,
 181                               key_perm_t perm);
 182
 183/*
 184 * Check to see whether permission is granted to use a key in the desired way.
 185 */
 186static inline int key_permission(const key_ref_t key_ref, unsigned perm)
 187{
 188        return key_task_permission(key_ref, current_cred(), perm);
 189}
 190
 191/*
 192 * Authorisation record for request_key().
 193 */
 194struct request_key_auth {
 195        struct key              *target_key;
 196        struct key              *dest_keyring;
 197        const struct cred       *cred;
 198        void                    *callout_info;
 199        size_t                  callout_len;
 200        pid_t                   pid;
 201} __randomize_layout;
 202
 203extern struct key_type key_type_request_key_auth;
 204extern struct key *request_key_auth_new(struct key *target,
 205                                        const void *callout_info,
 206                                        size_t callout_len,
 207                                        struct key *dest_keyring);
 208
 209extern struct key *key_get_instantiation_authkey(key_serial_t target_id);
 210
 211/*
 212 * Determine whether a key is dead.
 213 */
 214static inline bool key_is_dead(const struct key *key, time64_t limit)
 215{
 216        return
 217                key->flags & ((1 << KEY_FLAG_DEAD) |
 218                              (1 << KEY_FLAG_INVALIDATED)) ||
 219                (key->expiry > 0 && key->expiry <= limit);
 220}
 221
 222/*
 223 * keyctl() functions
 224 */
 225extern long keyctl_get_keyring_ID(key_serial_t, int);
 226extern long keyctl_join_session_keyring(const char __user *);
 227extern long keyctl_update_key(key_serial_t, const void __user *, size_t);
 228extern long keyctl_revoke_key(key_serial_t);
 229extern long keyctl_keyring_clear(key_serial_t);
 230extern long keyctl_keyring_link(key_serial_t, key_serial_t);
 231extern long keyctl_keyring_unlink(key_serial_t, key_serial_t);
 232extern long keyctl_describe_key(key_serial_t, char __user *, size_t);
 233extern long keyctl_keyring_search(key_serial_t, const char __user *,
 234                                  const char __user *, key_serial_t);
 235extern long keyctl_read_key(key_serial_t, char __user *, size_t);
 236extern long keyctl_chown_key(key_serial_t, uid_t, gid_t);
 237extern long keyctl_setperm_key(key_serial_t, key_perm_t);
 238extern long keyctl_instantiate_key(key_serial_t, const void __user *,
 239                                   size_t, key_serial_t);
 240extern long keyctl_negate_key(key_serial_t, unsigned, key_serial_t);
 241extern long keyctl_set_reqkey_keyring(int);
 242extern long keyctl_set_timeout(key_serial_t, unsigned);
 243extern long keyctl_assume_authority(key_serial_t);
 244extern long keyctl_get_security(key_serial_t keyid, char __user *buffer,
 245                                size_t buflen);
 246extern long keyctl_session_to_parent(void);
 247extern long keyctl_reject_key(key_serial_t, unsigned, unsigned, key_serial_t);
 248extern long keyctl_instantiate_key_iov(key_serial_t,
 249                                       const struct iovec __user *,
 250                                       unsigned, key_serial_t);
 251extern long keyctl_invalidate_key(key_serial_t);
 252
 253struct iov_iter;
 254extern long keyctl_instantiate_key_common(key_serial_t,
 255                                          struct iov_iter *,
 256                                          key_serial_t);
 257extern long keyctl_restrict_keyring(key_serial_t id,
 258                                    const char __user *_type,
 259                                    const char __user *_restriction);
 260#ifdef CONFIG_PERSISTENT_KEYRINGS
 261extern long keyctl_get_persistent(uid_t, key_serial_t);
 262extern unsigned persistent_keyring_expiry;
 263#else
 264static inline long keyctl_get_persistent(uid_t uid, key_serial_t destring)
 265{
 266        return -EOPNOTSUPP;
 267}
 268#endif
 269
 270#ifdef CONFIG_KEY_DH_OPERATIONS
 271extern long keyctl_dh_compute(struct keyctl_dh_params __user *, char __user *,
 272                              size_t, struct keyctl_kdf_params __user *);
 273extern long __keyctl_dh_compute(struct keyctl_dh_params __user *, char __user *,
 274                                size_t, struct keyctl_kdf_params *);
 275#ifdef CONFIG_KEYS_COMPAT
 276extern long compat_keyctl_dh_compute(struct keyctl_dh_params __user *params,
 277                                char __user *buffer, size_t buflen,
 278                                struct compat_keyctl_kdf_params __user *kdf);
 279#endif
 280#define KEYCTL_KDF_MAX_OUTPUT_LEN       1024    /* max length of KDF output */
 281#define KEYCTL_KDF_MAX_OI_LEN           64      /* max length of otherinfo */
 282#else
 283static inline long keyctl_dh_compute(struct keyctl_dh_params __user *params,
 284                                     char __user *buffer, size_t buflen,
 285                                     struct keyctl_kdf_params __user *kdf)
 286{
 287        return -EOPNOTSUPP;
 288}
 289
 290#ifdef CONFIG_KEYS_COMPAT
 291static inline long compat_keyctl_dh_compute(
 292                                struct keyctl_dh_params __user *params,
 293                                char __user *buffer, size_t buflen,
 294                                struct keyctl_kdf_params __user *kdf)
 295{
 296        return -EOPNOTSUPP;
 297}
 298#endif
 299#endif
 300
 301/*
 302 * Debugging key validation
 303 */
 304#ifdef KEY_DEBUGGING
 305extern void __key_check(const struct key *);
 306
 307static inline void key_check(const struct key *key)
 308{
 309        if (key && (IS_ERR(key) || key->magic != KEY_DEBUG_MAGIC))
 310                __key_check(key);
 311}
 312
 313#else
 314
 315#define key_check(key) do {} while(0)
 316
 317#endif
 318
 319#endif /* _INTERNAL_H */
 320