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
  18 #ifdef __KDEBUG
  19 #define kenter(FMT, ...) \
  20         printk(KERN_DEBUG "==> %s("FMT")\n", __func__, ##__VA_ARGS__)
  21 #define kleave(FMT, ...) \
  22         printk(KERN_DEBUG "<== %s()"FMT"\n", __func__, ##__VA_ARGS__)
  23 #define kdebug(FMT, ...) \
  24         printk(KERN_DEBUG "   "FMT"\n", ##__VA_ARGS__)
  25 #else
  26 #define kenter(FMT, ...) \
  27         no_printk(KERN_DEBUG "==> %s("FMT")\n", __func__, ##__VA_ARGS__)
  28 #define kleave(FMT, ...) \
  29         no_printk(KERN_DEBUG "<== %s()"FMT"\n", __func__, ##__VA_ARGS__)
  30 #define kdebug(FMT, ...) \
  31         no_printk(KERN_DEBUG FMT"\n", ##__VA_ARGS__)
  32 #endif
  33
  34 extern struct key_type key_type_user;
  35
  36 /*****************************************************************************/
  37 /*
  38  * Keep track of keys for a user.
  39  *
  40  * This needs to be separate to user_struct to avoid a refcount-loop
  41  * (user_struct pins some keyrings which pin this struct).
  42  *
  43  * We also keep track of keys under request from userspace for this UID here.
  44  */
  45 struct key_user {
  46         struct rb_node          node;
  47         struct mutex            cons_lock;      /* construction initiation lock */
  48         spinlock_t              lock;
  49         atomic_t                usage;          /* for accessing qnkeys & qnbytes */
  50         atomic_t                nkeys;          /* number of keys */
  51         atomic_t                nikeys;         /* number of instantiated keys */
  52         uid_t                   uid;
  53         struct user_namespace   *user_ns;
  54         int                     qnkeys;         /* number of keys allocated to this user */
  55         int                     qnbytes;        /* number of bytes allocated to this user */
  56 };
  57
  58 extern struct rb_root   key_user_tree;
  59 extern spinlock_t       key_user_lock;
  60 extern struct key_user  root_key_user;
  61
  62 extern struct key_user *key_user_lookup(uid_t uid,
  63                                         struct user_namespace *user_ns);
  64 extern void key_user_put(struct key_user *user);
  65
  66 /*
  67  * Key quota limits.
  68  * - root has its own separate limits to everyone else
  69  */
  70 extern unsigned key_quota_root_maxkeys;
  71 extern unsigned key_quota_root_maxbytes;
  72 extern unsigned key_quota_maxkeys;
  73 extern unsigned key_quota_maxbytes;
  74
  75 #define KEYQUOTA_LINK_BYTES     4               /* a link in a keyring is worth 4 bytes */
  76
  77
  78 extern struct rb_root key_serial_tree;
  79 extern spinlock_t key_serial_lock;
  80 extern struct mutex key_construction_mutex;
  81 extern wait_queue_head_t request_key_conswq;
  82
  83
  84 extern struct key_type *key_type_lookup(const char *type);
  85 extern void key_type_put(struct key_type *ktype);
  86
  87 extern int __key_link_begin(struct key *keyring,
  88                             const struct key_type *type,
  89                             const char *description,
  90                             unsigned long *_prealloc);
  91 extern int __key_link_check_live_key(struct key *keyring, struct key *key);
  92 extern void __key_link(struct key *keyring, struct key *key,
  93                        unsigned long *_prealloc);
  94 extern void __key_link_end(struct key *keyring,
  95                            struct key_type *type,
  96                            unsigned long prealloc);
  97
  98 extern key_ref_t __keyring_search_one(key_ref_t keyring_ref,
  99                                       const struct key_type *type,
 100                                       const char *description,
 101                                       key_perm_t perm);
 102
 103 extern struct key *keyring_search_instkey(struct key *keyring,
 104                                           key_serial_t target_id);
 105
 106 typedef int (*key_match_func_t)(const struct key *, const void *);
 107
 108 extern key_ref_t keyring_search_aux(key_ref_t keyring_ref,
 109                                     const struct cred *cred,
 110                                     struct key_type *type,
 111                                     const void *description,
 112                                     key_match_func_t match);
 113
 114 extern key_ref_t search_my_process_keyrings(struct key_type *type,
 115                                             const void *description,
 116                                             key_match_func_t match,
 117                                             const struct cred *cred);
 118 extern key_ref_t search_process_keyrings(struct key_type *type,
 119                                          const void *description,
 120                                          key_match_func_t match,
 121                                          const struct cred *cred);
 122
 123 extern struct key *find_keyring_by_name(const char *name, bool skip_perm_check);
 124
 125 extern int install_user_keyrings(void);
 126 extern int install_thread_keyring_to_cred(struct cred *);
 127 extern int install_process_keyring_to_cred(struct cred *);
 128 extern int install_session_keyring_to_cred(struct cred *, struct key *);
 129
 130 extern struct key *request_key_and_link(struct key_type *type,
 131                                         const char *description,
 132                                         const void *callout_info,
 133                                         size_t callout_len,
 134                                         void *aux,
 135                                         struct key *dest_keyring,
 136                                         unsigned long flags);
 137
 138 extern int lookup_user_key_possessed(const struct key *key, const void *target);
 139 extern key_ref_t lookup_user_key(key_serial_t id, unsigned long flags,
 140                                  key_perm_t perm);
 141 #define KEY_LOOKUP_CREATE       0x01
 142 #define KEY_LOOKUP_PARTIAL      0x02
 143 #define KEY_LOOKUP_FOR_UNLINK   0x04
 144
 145 extern long join_session_keyring(const char *name);
 146
 147 extern unsigned key_gc_delay;
 148 extern void keyring_gc(struct key *keyring, time_t limit);
 149 extern void key_schedule_gc(time_t expiry_at);
 150
 151 extern int key_task_permission(const key_ref_t key_ref,
 152                                const struct cred *cred,
 153                                key_perm_t perm);
 154
 155 /*
 156  * Check to see whether permission is granted to use a key in the desired way.
 157  */
 158 static inline int key_permission(const key_ref_t key_ref, key_perm_t perm)
 159 {
 160         return key_task_permission(key_ref, current_cred(), perm);
 161 }
 162
 163 /* required permissions */
 164 #define KEY_VIEW        0x01    /* require permission to view attributes */
 165 #define KEY_READ        0x02    /* require permission to read content */
 166 #define KEY_WRITE       0x04    /* require permission to update / modify */
 167 #define KEY_SEARCH      0x08    /* require permission to search (keyring) or find (key) */
 168 #define KEY_LINK        0x10    /* require permission to link */
 169 #define KEY_SETATTR     0x20    /* require permission to change attributes */
 170 #define KEY_ALL         0x3f    /* all the above permissions */
 171
 172 /*
 173  * Authorisation record for request_key().
 174  */
 175 struct request_key_auth {
 176         struct key              *target_key;
 177         struct key              *dest_keyring;
 178         const struct cred       *cred;
 179         void                    *callout_info;
 180         size_t                  callout_len;
 181         pid_t                   pid;
 182 };
 183
 184 extern struct key_type key_type_request_key_auth;
 185 extern struct key *request_key_auth_new(struct key *target,
 186                                         const void *callout_info,
 187                                         size_t callout_len,
 188                                         struct key *dest_keyring);
 189
 190 extern struct key *key_get_instantiation_authkey(key_serial_t target_id);
 191
 192 /*
 193  * keyctl() functions
 194  */
 195 extern long keyctl_get_keyring_ID(key_serial_t, int);
 196 extern long keyctl_join_session_keyring(const char __user *);
 197 extern long keyctl_update_key(key_serial_t, const void __user *, size_t);
 198 extern long keyctl_revoke_key(key_serial_t);
 199 extern long keyctl_keyring_clear(key_serial_t);
 200 extern long keyctl_keyring_link(key_serial_t, key_serial_t);
 201 extern long keyctl_keyring_unlink(key_serial_t, key_serial_t);
 202 extern long keyctl_describe_key(key_serial_t, char __user *, size_t);
 203 extern long keyctl_keyring_search(key_serial_t, const char __user *,
 204                                   const char __user *, key_serial_t);
 205 extern long keyctl_read_key(key_serial_t, char __user *, size_t);
 206 extern long keyctl_chown_key(key_serial_t, uid_t, gid_t);
 207 extern long keyctl_setperm_key(key_serial_t, key_perm_t);
 208 extern long keyctl_instantiate_key(key_serial_t, const void __user *,
 209                                    size_t, key_serial_t);
 210 extern long keyctl_negate_key(key_serial_t, unsigned, key_serial_t);
 211 extern long keyctl_set_reqkey_keyring(int);
 212 extern long keyctl_set_timeout(key_serial_t, unsigned);
 213 extern long keyctl_assume_authority(key_serial_t);
 214 extern long keyctl_get_security(key_serial_t keyid, char __user *buffer,
 215                                 size_t buflen);
 216 extern long keyctl_session_to_parent(void);
 217 extern long keyctl_reject_key(key_serial_t, unsigned, unsigned, key_serial_t);
 218 extern long keyctl_instantiate_key_iov(key_serial_t,
 219                                        const struct iovec __user *,
 220                                        unsigned, key_serial_t);
 221
 222 extern long keyctl_instantiate_key_common(key_serial_t,
 223                                           const struct iovec __user *,
 224                                           unsigned, size_t, key_serial_t);
 225
 226 /*
 227  * Debugging key validation
 228  */
 229 #ifdef KEY_DEBUGGING
 230 extern void __key_check(const struct key *);
 231
 232 static inline void key_check(const struct key *key)
 233 {
 234         if (key && (IS_ERR(key) || key->magic != KEY_DEBUG_MAGIC))
 235                 __key_check(key);
 236 }
 237
 238 #else
 239
 240 #define key_check(key) do {} while(0)
 241
 242 #endif
 243
 244 #endif /* _INTERNAL_H */