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/key-type.h>
  17 #include <linux/task_work.h>
  18
  19 #ifdef __KDEBUG
  20 #define kenter(FMT, ...) \
  21         printk(KERN_DEBUG "==> %s("FMT")\n", __func__, ##__VA_ARGS__)
  22 #define kleave(FMT, ...) \
  23         printk(KERN_DEBUG "<== %s()"FMT"\n", __func__, ##__VA_ARGS__)
  24 #define kdebug(FMT, ...) \
  25         printk(KERN_DEBUG "   "FMT"\n", ##__VA_ARGS__)
  26 #else
  27 #define kenter(FMT, ...) \
  28         no_printk(KERN_DEBUG "==> %s("FMT")\n", __func__, ##__VA_ARGS__)
  29 #define kleave(FMT, ...) \
  30         no_printk(KERN_DEBUG "<== %s()"FMT"\n", __func__, ##__VA_ARGS__)
  31 #define kdebug(FMT, ...) \
  32         no_printk(KERN_DEBUG FMT"\n", ##__VA_ARGS__)
  33 #endif
  34
  35 extern struct key_type key_type_dead;
  36 extern struct key_type key_type_user;
  37 extern struct key_type key_type_logon;
  38
  39 /*****************************************************************************/
  40 /*
  41  * Keep track of keys for a user.
  42  *
  43  * This needs to be separate to user_struct to avoid a refcount-loop
  44  * (user_struct pins some keyrings which pin this struct).
  45  *
  46  * We also keep track of keys under request from userspace for this UID here.
  47  */
  48 struct key_user {
  49         struct rb_node          node;
  50         struct mutex            cons_lock;      /* construction initiation lock */
  51         spinlock_t              lock;
  52         atomic_t                usage;          /* for accessing qnkeys & qnbytes */
  53         atomic_t                nkeys;          /* number of keys */
  54         atomic_t                nikeys;         /* number of instantiated keys */
  55         uid_t                   uid;
  56         struct user_namespace   *user_ns;
  57         int                     qnkeys;         /* number of keys allocated to this user */
  58         int                     qnbytes;        /* number of bytes allocated to this user */
  59 };
  60
  61 extern struct rb_root   key_user_tree;
  62 extern spinlock_t       key_user_lock;
  63 extern struct key_user  root_key_user;
  64
  65 extern struct key_user *key_user_lookup(uid_t uid,
  66                                         struct user_namespace *user_ns);
  67 extern void key_user_put(struct key_user *user);
  68
  69 /*
  70  * Key quota limits.
  71  * - root has its own separate limits to everyone else
  72  */
  73 extern unsigned key_quota_root_maxkeys;
  74 extern unsigned key_quota_root_maxbytes;
  75 extern unsigned key_quota_maxkeys;
  76 extern unsigned key_quota_maxbytes;
  77
  78 #define KEYQUOTA_LINK_BYTES     4               /* a link in a keyring is worth 4 bytes */
  79
  80
  81 extern struct kmem_cache *key_jar;
  82 extern struct rb_root key_serial_tree;
  83 extern spinlock_t key_serial_lock;
  84 extern struct mutex key_construction_mutex;
  85 extern wait_queue_head_t request_key_conswq;
  86
  87
  88 extern struct key_type *key_type_lookup(const char *type);
  89 extern void key_type_put(struct key_type *ktype);
  90
  91 extern int __key_link_begin(struct key *keyring,
  92                             const struct key_type *type,
  93                             const char *description,
  94                             unsigned long *_prealloc);
  95 extern int __key_link_check_live_key(struct key *keyring, struct key *key);
  96 extern void __key_link(struct key *keyring, struct key *key,
  97                        unsigned long *_prealloc);
  98 extern void __key_link_end(struct key *keyring,
  99                            struct key_type *type,
 100                            unsigned long prealloc);
 101
 102 extern key_ref_t __keyring_search_one(key_ref_t keyring_ref,
 103                                       const struct key_type *type,
 104                                       const char *description,
 105                                       key_perm_t perm);
 106
 107 extern struct key *keyring_search_instkey(struct key *keyring,
 108                                           key_serial_t target_id);
 109
 110 typedef int (*key_match_func_t)(const struct key *, const void *);
 111
 112 extern key_ref_t keyring_search_aux(key_ref_t keyring_ref,
 113                                     const struct cred *cred,
 114                                     struct key_type *type,
 115                                     const void *description,
 116                                     key_match_func_t match,
 117                                     bool no_state_check);
 118
 119 extern key_ref_t search_my_process_keyrings(struct key_type *type,
 120                                             const void *description,
 121                                             key_match_func_t match,
 122                                             bool no_state_check,
 123                                             const struct cred *cred);
 124 extern key_ref_t search_process_keyrings(struct key_type *type,
 125                                          const void *description,
 126                                          key_match_func_t match,
 127                                          const struct cred *cred);
 128
 129 extern struct key *find_keyring_by_name(const char *name, bool skip_perm_check);
 130
 131 extern int install_user_keyrings(void);
 132 extern int install_thread_keyring_to_cred(struct cred *);
 133 extern int install_process_keyring_to_cred(struct cred *);
 134 extern int install_session_keyring_to_cred(struct cred *, struct key *);
 135
 136 extern struct key *request_key_and_link(struct key_type *type,
 137                                         const char *description,
 138                                         const void *callout_info,
 139                                         size_t callout_len,
 140                                         void *aux,
 141                                         struct key *dest_keyring,
 142                                         unsigned long flags);
 143
 144 extern int lookup_user_key_possessed(const struct key *key, const void *target);
 145 extern key_ref_t lookup_user_key(key_serial_t id, unsigned long flags,
 146                                  key_perm_t perm);
 147 #define KEY_LOOKUP_CREATE       0x01
 148 #define KEY_LOOKUP_PARTIAL      0x02
 149 #define KEY_LOOKUP_FOR_UNLINK   0x04
 150
 151 extern long join_session_keyring(const char *name);
 152 extern void key_change_session_keyring(struct callback_head *twork);
 153
 154 extern struct work_struct key_gc_work;
 155 extern unsigned key_gc_delay;
 156 extern void keyring_gc(struct key *keyring, time_t limit);
 157 extern void key_schedule_gc(time_t gc_at);
 158 extern void key_schedule_gc_links(void);
 159 extern void key_gc_keytype(struct key_type *ktype);
 160
 161 extern int key_task_permission(const key_ref_t key_ref,
 162                                const struct cred *cred,
 163                                key_perm_t perm);
 164
 165 /*
 166  * Check to see whether permission is granted to use a key in the desired way.
 167  */
 168 static inline int key_permission(const key_ref_t key_ref, key_perm_t perm)
 169 {
 170         return key_task_permission(key_ref, current_cred(), perm);
 171 }
 172
 173 /* required permissions */
 174 #define KEY_VIEW        0x01    /* require permission to view attributes */
 175 #define KEY_READ        0x02    /* require permission to read content */
 176 #define KEY_WRITE       0x04    /* require permission to update / modify */
 177 #define KEY_SEARCH      0x08    /* require permission to search (keyring) or find (key) */
 178 #define KEY_LINK        0x10    /* require permission to link */
 179 #define KEY_SETATTR     0x20    /* require permission to change attributes */
 180 #define KEY_ALL         0x3f    /* all the above permissions */
 181
 182 /*
 183  * Authorisation record for request_key().
 184  */
 185 struct request_key_auth {
 186         struct key              *target_key;
 187         struct key              *dest_keyring;
 188         const struct cred       *cred;
 189         void                    *callout_info;
 190         size_t                  callout_len;
 191         pid_t                   pid;
 192 };
 193
 194 extern struct key_type key_type_request_key_auth;
 195 extern struct key *request_key_auth_new(struct key *target,
 196                                         const void *callout_info,
 197                                         size_t callout_len,
 198                                         struct key *dest_keyring);
 199
 200 extern struct key *key_get_instantiation_authkey(key_serial_t target_id);
 201
 202 /*
 203  * Determine whether a key is dead.
 204  */
 205 static inline bool key_is_dead(struct key *key, time_t limit)
 206 {
 207         return
 208                 key->flags & ((1 << KEY_FLAG_DEAD) |
 209                               (1 << KEY_FLAG_INVALIDATED)) ||
 210                 (key->expiry > 0 && key->expiry <= limit);
 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_unlink(key_serial_t, key_serial_t);
 223 extern long keyctl_describe_key(key_serial_t, char __user *, size_t);
 224 extern long keyctl_keyring_search(key_serial_t, const char __user *,
 225                                   const char __user *, key_serial_t);
 226 extern long keyctl_read_key(key_serial_t, char __user *, size_t);
 227 extern long keyctl_chown_key(key_serial_t, uid_t, gid_t);
 228 extern long keyctl_setperm_key(key_serial_t, key_perm_t);
 229 extern long keyctl_instantiate_key(key_serial_t, const void __user *,
 230                                    size_t, key_serial_t);
 231 extern long keyctl_negate_key(key_serial_t, unsigned, key_serial_t);
 232 extern long keyctl_set_reqkey_keyring(int);
 233 extern long keyctl_set_timeout(key_serial_t, unsigned);
 234 extern long keyctl_assume_authority(key_serial_t);
 235 extern long keyctl_get_security(key_serial_t keyid, char __user *buffer,
 236                                 size_t buflen);
 237 extern long keyctl_session_to_parent(void);
 238 extern long keyctl_reject_key(key_serial_t, unsigned, unsigned, key_serial_t);
 239 extern long keyctl_instantiate_key_iov(key_serial_t,
 240                                        const struct iovec __user *,
 241                                        unsigned, key_serial_t);
 242 extern long keyctl_invalidate_key(key_serial_t);
 243
 244 extern long keyctl_instantiate_key_common(key_serial_t,
 245                                           const struct iovec *,
 246                                           unsigned, size_t, key_serial_t);
 247
 248 /*
 249  * Debugging key validation
 250  */
 251 #ifdef KEY_DEBUGGING
 252 extern void __key_check(const struct key *);
 253
 254 static inline void key_check(const struct key *key)
 255 {
 256         if (key && (IS_ERR(key) || key->magic != KEY_DEBUG_MAGIC))
 257                 __key_check(key);
 258 }
 259
 260 #else
 261
 262 #define key_check(key) do {} while(0)
 263
 264 #endif
 265
 266 #endif /* _INTERNAL_H */