security/keys/internal.h

   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
  24 struct 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
  42 extern struct key_type key_type_dead;
  43 extern struct key_type key_type_user;
  44 extern 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  */
  55 struct 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
  67 extern struct rb_root   key_user_tree;
  68 extern spinlock_t       key_user_lock;
  69 extern struct key_user  root_key_user;
  70
  71 extern struct key_user *key_user_lookup(kuid_t uid);
  72 extern 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  */
  78 extern unsigned key_quota_root_maxkeys;
  79 extern unsigned key_quota_root_maxbytes;
  80 extern unsigned key_quota_maxkeys;
  81 extern unsigned key_quota_maxbytes;
  82
  83 #define KEYQUOTA_LINK_BYTES     4               /* a link in a keyring is worth 4 bytes */
  84
  85
  86 extern struct kmem_cache *key_jar;
  87 extern struct rb_root key_serial_tree;
  88 extern spinlock_t key_serial_lock;
  89 extern struct mutex key_construction_mutex;
  90 extern wait_queue_head_t request_key_conswq;
  91
  92
  93 extern struct key_type *key_type_lookup(const char *type);
  94 extern void key_type_put(struct key_type *ktype);
  95
  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
 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         struct timespec         now;
 134 };
 135
 136 extern bool key_default_cmp(const struct key *key,
 137                             const struct key_match_data *match_data);
 138 extern key_ref_t keyring_search_aux(key_ref_t keyring_ref,
 139                                     struct keyring_search_context *ctx);
 140
 141 extern key_ref_t search_my_process_keyrings(struct keyring_search_context *ctx);
 142 extern key_ref_t search_process_keyrings(struct keyring_search_context *ctx);
 143
 144 extern struct key *find_keyring_by_name(const char *name, bool uid_keyring);
 145
 146 extern int install_user_keyrings(void);
 147 extern int install_thread_keyring_to_cred(struct cred *);
 148 extern int install_process_keyring_to_cred(struct cred *);
 149 extern int install_session_keyring_to_cred(struct cred *, struct key *);
 150
 151 extern 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
 159 extern bool lookup_user_key_possessed(const struct key *key,
 160                                       const struct key_match_data *match_data);
 161 extern 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
 167 extern long join_session_keyring(const char *name);
 168 extern void key_change_session_keyring(struct callback_head *twork);
 169
 170 extern struct work_struct key_gc_work;
 171 extern unsigned key_gc_delay;
 172 extern void keyring_gc(struct key *keyring, time_t limit);
 173 extern void keyring_restriction_gc(struct key *keyring,
 174                                    struct key_type *dead_type);
 175 extern void key_schedule_gc(time_t gc_at);
 176 extern void key_schedule_gc_links(void);
 177 extern void key_gc_keytype(struct key_type *ktype);
 178
 179 extern 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  */
 186 static 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  */
 194 struct 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
 203 extern struct key_type key_type_request_key_auth;
 204 extern 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
 209 extern struct key *key_get_instantiation_authkey(key_serial_t target_id);
 210
 211 /*
 212  * Determine whether a key is dead.
 213  */
 214 static inline bool key_is_dead(const struct key *key, time_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  */
 225 extern long keyctl_get_keyring_ID(key_serial_t, int);
 226 extern long keyctl_join_session_keyring(const char __user *);
 227 extern long keyctl_update_key(key_serial_t, const void __user *, size_t);
 228 extern long keyctl_revoke_key(key_serial_t);
 229 extern long keyctl_keyring_clear(key_serial_t);
 230 extern long keyctl_keyring_link(key_serial_t, key_serial_t);
 231 extern long keyctl_keyring_unlink(key_serial_t, key_serial_t);
 232 extern long keyctl_describe_key(key_serial_t, char __user *, size_t);
 233 extern long keyctl_keyring_search(key_serial_t, const char __user *,
 234                                   const char __user *, key_serial_t);
 235 extern long keyctl_read_key(key_serial_t, char __user *, size_t);
 236 extern long keyctl_chown_key(key_serial_t, uid_t, gid_t);
 237 extern long keyctl_setperm_key(key_serial_t, key_perm_t);
 238 extern long keyctl_instantiate_key(key_serial_t, const void __user *,
 239                                    size_t, key_serial_t);
 240 extern long keyctl_negate_key(key_serial_t, unsigned, key_serial_t);
 241 extern long keyctl_set_reqkey_keyring(int);
 242 extern long keyctl_set_timeout(key_serial_t, unsigned);
 243 extern long keyctl_assume_authority(key_serial_t);
 244 extern long keyctl_get_security(key_serial_t keyid, char __user *buffer,
 245                                 size_t buflen);
 246 extern long keyctl_session_to_parent(void);
 247 extern long keyctl_reject_key(key_serial_t, unsigned, unsigned, key_serial_t);
 248 extern long keyctl_instantiate_key_iov(key_serial_t,
 249                                        const struct iovec __user *,
 250                                        unsigned, key_serial_t);
 251 extern long keyctl_invalidate_key(key_serial_t);
 252
 253 struct iov_iter;
 254 extern long keyctl_instantiate_key_common(key_serial_t,
 255                                           struct iov_iter *,
 256                                           key_serial_t);
 257 extern long keyctl_restrict_keyring(key_serial_t id,
 258                                     const char __user *_type,
 259                                     const char __user *_restriction);
 260 #ifdef CONFIG_PERSISTENT_KEYRINGS
 261 extern long keyctl_get_persistent(uid_t, key_serial_t);
 262 extern unsigned persistent_keyring_expiry;
 263 #else
 264 static 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
 271 extern long keyctl_dh_compute(struct keyctl_dh_params __user *, char __user *,
 272                               size_t, struct keyctl_kdf_params __user *);
 273 extern long __keyctl_dh_compute(struct keyctl_dh_params __user *, char __user *,
 274                                 size_t, struct keyctl_kdf_params *);
 275 #ifdef CONFIG_KEYS_COMPAT
 276 extern 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
 283 static 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
 291 static 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
 305 extern void __key_check(const struct key *);
 306
 307 static 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 */