Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1 | /* key.h: authentication token and access key management |
| 2 | * |
| 3 | * Copyright (C) 2004 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 | * See Documentation/keys.txt for information on keys/keyrings. |
| 13 | */ |
| 14 | |
| 15 | #ifndef _LINUX_KEY_H |
| 16 | #define _LINUX_KEY_H |
| 17 | |
| 18 | #include <linux/types.h> |
| 19 | #include <linux/list.h> |
| 20 | #include <linux/rbtree.h> |
David Howells | 76d8aea | 2005-06-23 22:00:49 -0700 | [diff] [blame] | 21 | #include <linux/rcupdate.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 22 | #include <asm/atomic.h> |
| 23 | |
| 24 | #ifdef __KERNEL__ |
| 25 | |
| 26 | /* key handle serial number */ |
| 27 | typedef int32_t key_serial_t; |
| 28 | |
| 29 | /* key handle permissions mask */ |
| 30 | typedef uint32_t key_perm_t; |
| 31 | |
| 32 | struct key; |
| 33 | |
| 34 | #ifdef CONFIG_KEYS |
| 35 | |
| 36 | #undef KEY_DEBUGGING |
| 37 | |
David Howells | 664cceb | 2005-09-28 17:03:15 +0100 | [diff] [blame] | 38 | #define KEY_POS_VIEW 0x01000000 /* possessor can view a key's attributes */ |
| 39 | #define KEY_POS_READ 0x02000000 /* possessor can read key payload / view keyring */ |
| 40 | #define KEY_POS_WRITE 0x04000000 /* possessor can update key payload / add link to keyring */ |
| 41 | #define KEY_POS_SEARCH 0x08000000 /* possessor can find a key in search / search a keyring */ |
| 42 | #define KEY_POS_LINK 0x10000000 /* possessor can create a link to a key/keyring */ |
David Howells | 29db919 | 2005-10-30 15:02:44 -0800 | [diff] [blame] | 43 | #define KEY_POS_SETATTR 0x20000000 /* possessor can set key attributes */ |
| 44 | #define KEY_POS_ALL 0x3f000000 |
David Howells | 664cceb | 2005-09-28 17:03:15 +0100 | [diff] [blame] | 45 | |
| 46 | #define KEY_USR_VIEW 0x00010000 /* user permissions... */ |
| 47 | #define KEY_USR_READ 0x00020000 |
| 48 | #define KEY_USR_WRITE 0x00040000 |
| 49 | #define KEY_USR_SEARCH 0x00080000 |
| 50 | #define KEY_USR_LINK 0x00100000 |
David Howells | 29db919 | 2005-10-30 15:02:44 -0800 | [diff] [blame] | 51 | #define KEY_USR_SETATTR 0x00200000 |
| 52 | #define KEY_USR_ALL 0x003f0000 |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 53 | |
| 54 | #define KEY_GRP_VIEW 0x00000100 /* group permissions... */ |
| 55 | #define KEY_GRP_READ 0x00000200 |
| 56 | #define KEY_GRP_WRITE 0x00000400 |
| 57 | #define KEY_GRP_SEARCH 0x00000800 |
| 58 | #define KEY_GRP_LINK 0x00001000 |
David Howells | 29db919 | 2005-10-30 15:02:44 -0800 | [diff] [blame] | 59 | #define KEY_GRP_SETATTR 0x00002000 |
| 60 | #define KEY_GRP_ALL 0x00003f00 |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 61 | |
| 62 | #define KEY_OTH_VIEW 0x00000001 /* third party permissions... */ |
| 63 | #define KEY_OTH_READ 0x00000002 |
| 64 | #define KEY_OTH_WRITE 0x00000004 |
| 65 | #define KEY_OTH_SEARCH 0x00000008 |
| 66 | #define KEY_OTH_LINK 0x00000010 |
David Howells | 29db919 | 2005-10-30 15:02:44 -0800 | [diff] [blame] | 67 | #define KEY_OTH_SETATTR 0x00000020 |
| 68 | #define KEY_OTH_ALL 0x0000003f |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 69 | |
| 70 | struct seq_file; |
| 71 | struct user_struct; |
| 72 | struct signal_struct; |
| 73 | |
| 74 | struct key_type; |
| 75 | struct key_owner; |
| 76 | struct keyring_list; |
| 77 | struct keyring_name; |
| 78 | |
| 79 | /*****************************************************************************/ |
| 80 | /* |
David Howells | 664cceb | 2005-09-28 17:03:15 +0100 | [diff] [blame] | 81 | * key reference with possession attribute handling |
| 82 | * |
| 83 | * NOTE! key_ref_t is a typedef'd pointer to a type that is not actually |
| 84 | * defined. This is because we abuse the bottom bit of the reference to carry a |
| 85 | * flag to indicate whether the calling process possesses that key in one of |
| 86 | * its keyrings. |
| 87 | * |
| 88 | * the key_ref_t has been made a separate type so that the compiler can reject |
| 89 | * attempts to dereference it without proper conversion. |
| 90 | * |
| 91 | * the three functions are used to assemble and disassemble references |
| 92 | */ |
| 93 | typedef struct __key_reference_with_attributes *key_ref_t; |
| 94 | |
| 95 | static inline key_ref_t make_key_ref(const struct key *key, |
| 96 | unsigned long possession) |
| 97 | { |
| 98 | return (key_ref_t) ((unsigned long) key | possession); |
| 99 | } |
| 100 | |
| 101 | static inline struct key *key_ref_to_ptr(const key_ref_t key_ref) |
| 102 | { |
| 103 | return (struct key *) ((unsigned long) key_ref & ~1UL); |
| 104 | } |
| 105 | |
| 106 | static inline unsigned long is_key_possessed(const key_ref_t key_ref) |
| 107 | { |
| 108 | return (unsigned long) key_ref & 1UL; |
| 109 | } |
| 110 | |
| 111 | /*****************************************************************************/ |
| 112 | /* |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 113 | * authentication token / access credential / keyring |
| 114 | * - types of key include: |
| 115 | * - keyrings |
| 116 | * - disk encryption IDs |
| 117 | * - Kerberos TGTs and tickets |
| 118 | */ |
| 119 | struct key { |
| 120 | atomic_t usage; /* number of references */ |
| 121 | key_serial_t serial; /* key serial number */ |
| 122 | struct rb_node serial_node; |
| 123 | struct key_type *type; /* type of key */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 124 | struct rw_semaphore sem; /* change vs change sem */ |
| 125 | struct key_user *user; /* owner of this key */ |
David Howells | 29db919 | 2005-10-30 15:02:44 -0800 | [diff] [blame] | 126 | void *security; /* security data for this key */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 127 | time_t expiry; /* time at which key expires (or 0) */ |
| 128 | uid_t uid; |
| 129 | gid_t gid; |
| 130 | key_perm_t perm; /* access permissions */ |
| 131 | unsigned short quotalen; /* length added to quota */ |
David Howells | 76d8aea | 2005-06-23 22:00:49 -0700 | [diff] [blame] | 132 | unsigned short datalen; /* payload data length |
| 133 | * - may not match RCU dereferenced payload |
| 134 | * - payload should contain own length |
| 135 | */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 136 | |
| 137 | #ifdef KEY_DEBUGGING |
| 138 | unsigned magic; |
| 139 | #define KEY_DEBUG_MAGIC 0x18273645u |
| 140 | #define KEY_DEBUG_MAGIC_X 0xf8e9dacbu |
| 141 | #endif |
| 142 | |
David Howells | 76d8aea | 2005-06-23 22:00:49 -0700 | [diff] [blame] | 143 | unsigned long flags; /* status flags (change with bitops) */ |
| 144 | #define KEY_FLAG_INSTANTIATED 0 /* set if key has been instantiated */ |
| 145 | #define KEY_FLAG_DEAD 1 /* set if key type has been deleted */ |
| 146 | #define KEY_FLAG_REVOKED 2 /* set if key had been revoked */ |
| 147 | #define KEY_FLAG_IN_QUOTA 3 /* set if key consumes quota */ |
| 148 | #define KEY_FLAG_USER_CONSTRUCT 4 /* set if key is being constructed in userspace */ |
| 149 | #define KEY_FLAG_NEGATIVE 5 /* set if key is negative */ |
| 150 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 151 | /* the description string |
| 152 | * - this is used to match a key against search criteria |
| 153 | * - this should be a printable string |
| 154 | * - eg: for krb5 AFS, this might be "afs@REDHAT.COM" |
| 155 | */ |
| 156 | char *description; |
| 157 | |
| 158 | /* type specific data |
| 159 | * - this is used by the keyring type to index the name |
| 160 | */ |
| 161 | union { |
| 162 | struct list_head link; |
| 163 | } type_data; |
| 164 | |
| 165 | /* key data |
| 166 | * - this is used to hold the data actually used in cryptography or |
| 167 | * whatever |
| 168 | */ |
| 169 | union { |
| 170 | unsigned long value; |
| 171 | void *data; |
| 172 | struct keyring_list *subscriptions; |
| 173 | } payload; |
| 174 | }; |
| 175 | |
| 176 | /*****************************************************************************/ |
| 177 | /* |
| 178 | * kernel managed key type definition |
| 179 | */ |
David Howells | b5f545c | 2006-01-08 01:02:47 -0800 | [diff] [blame] | 180 | typedef int (*request_key_actor_t)(struct key *key, struct key *authkey, const char *op); |
| 181 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 182 | struct key_type { |
| 183 | /* name of the type */ |
| 184 | const char *name; |
| 185 | |
| 186 | /* default payload length for quota precalculation (optional) |
| 187 | * - this can be used instead of calling key_payload_reserve(), that |
| 188 | * function only needs to be called if the real datalen is different |
| 189 | */ |
| 190 | size_t def_datalen; |
| 191 | |
| 192 | /* instantiate a key of this type |
| 193 | * - this method should call key_payload_reserve() to determine if the |
| 194 | * user's quota will hold the payload |
| 195 | */ |
| 196 | int (*instantiate)(struct key *key, const void *data, size_t datalen); |
| 197 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 198 | /* update a key of this type (optional) |
| 199 | * - this method should call key_payload_reserve() to recalculate the |
| 200 | * quota consumption |
| 201 | * - the key must be locked against read when modifying |
| 202 | */ |
| 203 | int (*update)(struct key *key, const void *data, size_t datalen); |
| 204 | |
| 205 | /* match a key against a description */ |
| 206 | int (*match)(const struct key *key, const void *desc); |
| 207 | |
David Howells | 04c567d | 2006-06-22 14:47:18 -0700 | [diff] [blame] | 208 | /* clear some of the data from a key on revokation (optional) |
| 209 | * - the key's semaphore will be write-locked by the caller |
| 210 | */ |
| 211 | void (*revoke)(struct key *key); |
| 212 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 213 | /* clear the data from a key (optional) */ |
| 214 | void (*destroy)(struct key *key); |
| 215 | |
| 216 | /* describe a key */ |
| 217 | void (*describe)(const struct key *key, struct seq_file *p); |
| 218 | |
| 219 | /* read a key's data (optional) |
| 220 | * - permission checks will be done by the caller |
| 221 | * - the key's semaphore will be readlocked by the caller |
| 222 | * - should return the amount of data that could be read, no matter how |
| 223 | * much is copied into the buffer |
| 224 | * - shouldn't do the copy if the buffer is NULL |
| 225 | */ |
| 226 | long (*read)(const struct key *key, char __user *buffer, size_t buflen); |
| 227 | |
David Howells | b5f545c | 2006-01-08 01:02:47 -0800 | [diff] [blame] | 228 | /* handle request_key() for this type instead of invoking |
| 229 | * /sbin/request-key (optional) |
| 230 | * - key is the key to instantiate |
| 231 | * - authkey is the authority to assume when instantiating this key |
| 232 | * - op is the operation to be done, usually "create" |
| 233 | * - the call must not return until the instantiation process has run |
| 234 | * its course |
| 235 | */ |
| 236 | request_key_actor_t request_key; |
| 237 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 238 | /* internal fields */ |
| 239 | struct list_head link; /* link in types list */ |
| 240 | }; |
| 241 | |
| 242 | extern struct key_type key_type_keyring; |
| 243 | |
| 244 | extern int register_key_type(struct key_type *ktype); |
| 245 | extern void unregister_key_type(struct key_type *ktype); |
| 246 | |
| 247 | extern struct key *key_alloc(struct key_type *type, |
| 248 | const char *desc, |
Michael LeMay | d720024 | 2006-06-22 14:47:17 -0700 | [diff] [blame] | 249 | uid_t uid, gid_t gid, |
| 250 | struct task_struct *ctx, |
| 251 | key_perm_t perm, int not_in_quota); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 252 | extern int key_payload_reserve(struct key *key, size_t datalen); |
| 253 | extern int key_instantiate_and_link(struct key *key, |
| 254 | const void *data, |
| 255 | size_t datalen, |
David Howells | 3e30148 | 2005-06-23 22:00:56 -0700 | [diff] [blame] | 256 | struct key *keyring, |
| 257 | struct key *instkey); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 258 | extern int key_negate_and_link(struct key *key, |
| 259 | unsigned timeout, |
David Howells | 3e30148 | 2005-06-23 22:00:56 -0700 | [diff] [blame] | 260 | struct key *keyring, |
| 261 | struct key *instkey); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 262 | extern void key_revoke(struct key *key); |
| 263 | extern void key_put(struct key *key); |
| 264 | |
| 265 | static inline struct key *key_get(struct key *key) |
| 266 | { |
| 267 | if (key) |
| 268 | atomic_inc(&key->usage); |
| 269 | return key; |
| 270 | } |
| 271 | |
David Howells | 664cceb | 2005-09-28 17:03:15 +0100 | [diff] [blame] | 272 | static inline void key_ref_put(key_ref_t key_ref) |
| 273 | { |
| 274 | key_put(key_ref_to_ptr(key_ref)); |
| 275 | } |
| 276 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 277 | extern struct key *request_key(struct key_type *type, |
| 278 | const char *description, |
| 279 | const char *callout_info); |
| 280 | |
| 281 | extern int key_validate(struct key *key); |
| 282 | |
David Howells | 664cceb | 2005-09-28 17:03:15 +0100 | [diff] [blame] | 283 | extern key_ref_t key_create_or_update(key_ref_t keyring, |
| 284 | const char *type, |
| 285 | const char *description, |
| 286 | const void *payload, |
| 287 | size_t plen, |
| 288 | int not_in_quota); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 289 | |
David Howells | 664cceb | 2005-09-28 17:03:15 +0100 | [diff] [blame] | 290 | extern int key_update(key_ref_t key, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 291 | const void *payload, |
| 292 | size_t plen); |
| 293 | |
| 294 | extern int key_link(struct key *keyring, |
| 295 | struct key *key); |
| 296 | |
| 297 | extern int key_unlink(struct key *keyring, |
| 298 | struct key *key); |
| 299 | |
| 300 | extern struct key *keyring_alloc(const char *description, uid_t uid, gid_t gid, |
Michael LeMay | d720024 | 2006-06-22 14:47:17 -0700 | [diff] [blame] | 301 | struct task_struct *ctx, |
| 302 | int not_in_quota, |
| 303 | struct key *dest); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 304 | |
| 305 | extern int keyring_clear(struct key *keyring); |
| 306 | |
David Howells | 664cceb | 2005-09-28 17:03:15 +0100 | [diff] [blame] | 307 | extern key_ref_t keyring_search(key_ref_t keyring, |
| 308 | struct key_type *type, |
| 309 | const char *description); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 310 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 311 | extern int keyring_add_key(struct key *keyring, |
| 312 | struct key *key); |
| 313 | |
| 314 | extern struct key *key_lookup(key_serial_t id); |
| 315 | |
David Howells | 76d8aea | 2005-06-23 22:00:49 -0700 | [diff] [blame] | 316 | extern void keyring_replace_payload(struct key *key, void *replacement); |
| 317 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 318 | #define key_serial(key) ((key) ? (key)->serial : 0) |
| 319 | |
| 320 | /* |
| 321 | * the userspace interface |
| 322 | */ |
| 323 | extern struct key root_user_keyring, root_session_keyring; |
Michael LeMay | d720024 | 2006-06-22 14:47:17 -0700 | [diff] [blame] | 324 | extern int alloc_uid_keyring(struct user_struct *user, |
| 325 | struct task_struct *ctx); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 326 | extern void switch_uid_keyring(struct user_struct *new_user); |
| 327 | extern int copy_keys(unsigned long clone_flags, struct task_struct *tsk); |
| 328 | extern int copy_thread_group_keys(struct task_struct *tsk); |
| 329 | extern void exit_keys(struct task_struct *tsk); |
| 330 | extern void exit_thread_group_keys(struct signal_struct *tg); |
| 331 | extern int suid_keys(struct task_struct *tsk); |
| 332 | extern int exec_keys(struct task_struct *tsk); |
| 333 | extern void key_fsuid_changed(struct task_struct *tsk); |
| 334 | extern void key_fsgid_changed(struct task_struct *tsk); |
| 335 | extern void key_init(void); |
| 336 | |
David Howells | 7888e7f | 2005-06-23 22:00:51 -0700 | [diff] [blame] | 337 | #define __install_session_keyring(tsk, keyring) \ |
| 338 | ({ \ |
| 339 | struct key *old_session = tsk->signal->session_keyring; \ |
| 340 | tsk->signal->session_keyring = keyring; \ |
| 341 | old_session; \ |
| 342 | }) |
| 343 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 344 | #else /* CONFIG_KEYS */ |
| 345 | |
| 346 | #define key_validate(k) 0 |
| 347 | #define key_serial(k) 0 |
David Howells | 7888e7f | 2005-06-23 22:00:51 -0700 | [diff] [blame] | 348 | #define key_get(k) ({ NULL; }) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 349 | #define key_put(k) do { } while(0) |
David Howells | 664cceb | 2005-09-28 17:03:15 +0100 | [diff] [blame] | 350 | #define key_ref_put(k) do { } while(0) |
| 351 | #define make_key_ref(k) ({ NULL; }) |
| 352 | #define key_ref_to_ptr(k) ({ NULL; }) |
| 353 | #define is_key_possessed(k) 0 |
Michael LeMay | d720024 | 2006-06-22 14:47:17 -0700 | [diff] [blame] | 354 | #define alloc_uid_keyring(u,c) 0 |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 355 | #define switch_uid_keyring(u) do { } while(0) |
David Howells | 7888e7f | 2005-06-23 22:00:51 -0700 | [diff] [blame] | 356 | #define __install_session_keyring(t, k) ({ NULL; }) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 357 | #define copy_keys(f,t) 0 |
| 358 | #define copy_thread_group_keys(t) 0 |
| 359 | #define exit_keys(t) do { } while(0) |
| 360 | #define exit_thread_group_keys(tg) do { } while(0) |
| 361 | #define suid_keys(t) do { } while(0) |
| 362 | #define exec_keys(t) do { } while(0) |
| 363 | #define key_fsuid_changed(t) do { } while(0) |
| 364 | #define key_fsgid_changed(t) do { } while(0) |
| 365 | #define key_init() do { } while(0) |
| 366 | |
Michael LeMay | d720024 | 2006-06-22 14:47:17 -0700 | [diff] [blame] | 367 | /* Initial keyrings */ |
| 368 | extern struct key root_user_keyring; |
| 369 | extern struct key root_session_keyring; |
| 370 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 371 | #endif /* CONFIG_KEYS */ |
| 372 | #endif /* __KERNEL__ */ |
| 373 | #endif /* _LINUX_KEY_H */ |