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1/**
2 * eCryptfs: Linux filesystem encryption layer
3 * Kernel declarations.
4 *
5 * Copyright (C) 1997-2003 Erez Zadok
6 * Copyright (C) 2001-2003 Stony Brook University
7 * Copyright (C) 2004-2008 International Business Machines Corp.
8 * Author(s): Michael A. Halcrow <mahalcro@us.ibm.com>
9 * Trevor S. Highland <trevor.highland@gmail.com>
10 * Tyler Hicks <tyhicks@ou.edu>
11 *
12 * This program is free software; you can redistribute it and/or
13 * modify it under the terms of the GNU General Public License as
14 * published by the Free Software Foundation; either version 2 of the
15 * License, or (at your option) any later version.
16 *
17 * This program is distributed in the hope that it will be useful, but
18 * WITHOUT ANY WARRANTY; without even the implied warranty of
19 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
20 * General Public License for more details.
21 *
22 * You should have received a copy of the GNU General Public License
23 * along with this program; if not, write to the Free Software
24 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA
25 * 02111-1307, USA.
26 */
27
28#ifndef ECRYPTFS_KERNEL_H
29#define ECRYPTFS_KERNEL_H
30
31#include <crypto/skcipher.h>
32#include <keys/user-type.h>
33#include <keys/encrypted-type.h>
34#include <linux/fs.h>
35#include <linux/fs_stack.h>
36#include <linux/namei.h>
37#include <linux/scatterlist.h>
38#include <linux/hash.h>
39#include <linux/nsproxy.h>
40#include <linux/backing-dev.h>
41#include <linux/ecryptfs.h>
42
43#define ECRYPTFS_DEFAULT_IV_BYTES 16
44#define ECRYPTFS_DEFAULT_EXTENT_SIZE 4096
45#define ECRYPTFS_MINIMUM_HEADER_EXTENT_SIZE 8192
46#define ECRYPTFS_DEFAULT_MSG_CTX_ELEMS 32
47#define ECRYPTFS_DEFAULT_SEND_TIMEOUT HZ
48#define ECRYPTFS_MAX_MSG_CTX_TTL (HZ*3)
49#define ECRYPTFS_DEFAULT_NUM_USERS 4
50#define ECRYPTFS_MAX_NUM_USERS 32768
51#define ECRYPTFS_XATTR_NAME "user.ecryptfs"
52
53void ecryptfs_dump_auth_tok(struct ecryptfs_auth_tok *auth_tok);
54extern void ecryptfs_to_hex(char *dst, char *src, size_t src_size);
55extern void ecryptfs_from_hex(char *dst, char *src, int dst_size);
56
57struct ecryptfs_key_record {
58 unsigned char type;
59 size_t enc_key_size;
60 unsigned char sig[ECRYPTFS_SIG_SIZE];
61 unsigned char enc_key[ECRYPTFS_MAX_ENCRYPTED_KEY_BYTES];
62};
63
64struct ecryptfs_auth_tok_list {
65 struct ecryptfs_auth_tok *auth_tok;
66 struct list_head list;
67};
68
69struct ecryptfs_crypt_stat;
70struct ecryptfs_mount_crypt_stat;
71
72struct ecryptfs_page_crypt_context {
73 struct page *page;
74#define ECRYPTFS_PREPARE_COMMIT_MODE 0
75#define ECRYPTFS_WRITEPAGE_MODE 1
76 unsigned int mode;
77 union {
78 struct file *lower_file;
79 struct writeback_control *wbc;
80 } param;
81};
82
83#if defined(CONFIG_ENCRYPTED_KEYS) || defined(CONFIG_ENCRYPTED_KEYS_MODULE)
84static inline struct ecryptfs_auth_tok *
85ecryptfs_get_encrypted_key_payload_data(struct key *key)
86{
87 if (key->type == &key_type_encrypted)
88 return (struct ecryptfs_auth_tok *)
89 (&((struct encrypted_key_payload *)key->payload.data[0])->payload_data);
90 else
91 return NULL;
92}
93
94static inline struct key *ecryptfs_get_encrypted_key(char *sig)
95{
96 return request_key(&key_type_encrypted, sig, NULL);
97}
98
99#else
100static inline struct ecryptfs_auth_tok *
101ecryptfs_get_encrypted_key_payload_data(struct key *key)
102{
103 return NULL;
104}
105
106static inline struct key *ecryptfs_get_encrypted_key(char *sig)
107{
108 return ERR_PTR(-ENOKEY);
109}
110
111#endif /* CONFIG_ENCRYPTED_KEYS */
112
113static inline struct ecryptfs_auth_tok *
114ecryptfs_get_key_payload_data(struct key *key)
115{
116 struct ecryptfs_auth_tok *auth_tok;
117
118 auth_tok = ecryptfs_get_encrypted_key_payload_data(key);
119 if (!auth_tok)
120 return (struct ecryptfs_auth_tok *)user_key_payload(key)->data;
121 else
122 return auth_tok;
123}
124
125#define ECRYPTFS_MAX_KEYSET_SIZE 1024
126#define ECRYPTFS_MAX_CIPHER_NAME_SIZE 31
127#define ECRYPTFS_MAX_NUM_ENC_KEYS 64
128#define ECRYPTFS_MAX_IV_BYTES 16 /* 128 bits */
129#define ECRYPTFS_SALT_BYTES 2
130#define MAGIC_ECRYPTFS_MARKER 0x3c81b7f5
131#define MAGIC_ECRYPTFS_MARKER_SIZE_BYTES 8 /* 4*2 */
132#define ECRYPTFS_FILE_SIZE_BYTES (sizeof(u64))
133#define ECRYPTFS_SIZE_AND_MARKER_BYTES (ECRYPTFS_FILE_SIZE_BYTES \
134 + MAGIC_ECRYPTFS_MARKER_SIZE_BYTES)
135#define ECRYPTFS_DEFAULT_CIPHER "aes"
136#define ECRYPTFS_DEFAULT_KEY_BYTES 16
137#define ECRYPTFS_DEFAULT_HASH "md5"
138#define ECRYPTFS_TAG_70_DIGEST ECRYPTFS_DEFAULT_HASH
139#define ECRYPTFS_TAG_1_PACKET_TYPE 0x01
140#define ECRYPTFS_TAG_3_PACKET_TYPE 0x8C
141#define ECRYPTFS_TAG_11_PACKET_TYPE 0xED
142#define ECRYPTFS_TAG_64_PACKET_TYPE 0x40
143#define ECRYPTFS_TAG_65_PACKET_TYPE 0x41
144#define ECRYPTFS_TAG_66_PACKET_TYPE 0x42
145#define ECRYPTFS_TAG_67_PACKET_TYPE 0x43
146#define ECRYPTFS_TAG_70_PACKET_TYPE 0x46 /* FNEK-encrypted filename
147 * as dentry name */
148#define ECRYPTFS_TAG_71_PACKET_TYPE 0x47 /* FNEK-encrypted filename in
149 * metadata */
150#define ECRYPTFS_TAG_72_PACKET_TYPE 0x48 /* FEK-encrypted filename as
151 * dentry name */
152#define ECRYPTFS_TAG_73_PACKET_TYPE 0x49 /* FEK-encrypted filename as
153 * metadata */
154#define ECRYPTFS_MIN_PKT_LEN_SIZE 1 /* Min size to specify packet length */
155#define ECRYPTFS_MAX_PKT_LEN_SIZE 2 /* Pass at least this many bytes to
156 * ecryptfs_parse_packet_length() and
157 * ecryptfs_write_packet_length()
158 */
159/* Constraint: ECRYPTFS_FILENAME_MIN_RANDOM_PREPEND_BYTES >=
160 * ECRYPTFS_MAX_IV_BYTES */
161#define ECRYPTFS_FILENAME_MIN_RANDOM_PREPEND_BYTES 16
162#define ECRYPTFS_NON_NULL 0x42 /* A reasonable substitute for NULL */
163#define MD5_DIGEST_SIZE 16
164#define ECRYPTFS_TAG_70_DIGEST_SIZE MD5_DIGEST_SIZE
165#define ECRYPTFS_TAG_70_MIN_METADATA_SIZE (1 + ECRYPTFS_MIN_PKT_LEN_SIZE \
166 + ECRYPTFS_SIG_SIZE + 1 + 1)
167#define ECRYPTFS_TAG_70_MAX_METADATA_SIZE (1 + ECRYPTFS_MAX_PKT_LEN_SIZE \
168 + ECRYPTFS_SIG_SIZE + 1 + 1)
169#define ECRYPTFS_FEK_ENCRYPTED_FILENAME_PREFIX "ECRYPTFS_FEK_ENCRYPTED."
170#define ECRYPTFS_FEK_ENCRYPTED_FILENAME_PREFIX_SIZE 23
171#define ECRYPTFS_FNEK_ENCRYPTED_FILENAME_PREFIX "ECRYPTFS_FNEK_ENCRYPTED."
172#define ECRYPTFS_FNEK_ENCRYPTED_FILENAME_PREFIX_SIZE 24
173#define ECRYPTFS_ENCRYPTED_DENTRY_NAME_LEN (18 + 1 + 4 + 1 + 32)
174
175#ifdef CONFIG_ECRYPT_FS_MESSAGING
176# define ECRYPTFS_VERSIONING_MASK_MESSAGING (ECRYPTFS_VERSIONING_DEVMISC \
177 | ECRYPTFS_VERSIONING_PUBKEY)
178#else
179# define ECRYPTFS_VERSIONING_MASK_MESSAGING 0
180#endif
181
182#define ECRYPTFS_VERSIONING_MASK (ECRYPTFS_VERSIONING_PASSPHRASE \
183 | ECRYPTFS_VERSIONING_PLAINTEXT_PASSTHROUGH \
184 | ECRYPTFS_VERSIONING_XATTR \
185 | ECRYPTFS_VERSIONING_MULTKEY \
186 | ECRYPTFS_VERSIONING_MASK_MESSAGING \
187 | ECRYPTFS_VERSIONING_FILENAME_ENCRYPTION)
188struct ecryptfs_key_sig {
189 struct list_head crypt_stat_list;
190 char keysig[ECRYPTFS_SIG_SIZE_HEX + 1];
191};
192
193struct ecryptfs_filename {
194 struct list_head crypt_stat_list;
195#define ECRYPTFS_FILENAME_CONTAINS_DECRYPTED 0x00000001
196 u32 flags;
197 u32 seq_no;
198 char *filename;
199 char *encrypted_filename;
200 size_t filename_size;
201 size_t encrypted_filename_size;
202 char fnek_sig[ECRYPTFS_SIG_SIZE_HEX];
203 char dentry_name[ECRYPTFS_ENCRYPTED_DENTRY_NAME_LEN + 1];
204};
205
206/**
207 * This is the primary struct associated with each encrypted file.
208 *
209 * TODO: cache align/pack?
210 */
211struct ecryptfs_crypt_stat {
212#define ECRYPTFS_STRUCT_INITIALIZED 0x00000001
213#define ECRYPTFS_POLICY_APPLIED 0x00000002
214#define ECRYPTFS_ENCRYPTED 0x00000004
215#define ECRYPTFS_SECURITY_WARNING 0x00000008
216#define ECRYPTFS_ENABLE_HMAC 0x00000010
217#define ECRYPTFS_ENCRYPT_IV_PAGES 0x00000020
218#define ECRYPTFS_KEY_VALID 0x00000040
219#define ECRYPTFS_METADATA_IN_XATTR 0x00000080
220#define ECRYPTFS_VIEW_AS_ENCRYPTED 0x00000100
221#define ECRYPTFS_KEY_SET 0x00000200
222#define ECRYPTFS_ENCRYPT_FILENAMES 0x00000400
223#define ECRYPTFS_ENCFN_USE_MOUNT_FNEK 0x00000800
224#define ECRYPTFS_ENCFN_USE_FEK 0x00001000
225#define ECRYPTFS_UNLINK_SIGS 0x00002000
226#define ECRYPTFS_I_SIZE_INITIALIZED 0x00004000
227 u32 flags;
228 unsigned int file_version;
229 size_t iv_bytes;
230 size_t metadata_size;
231 size_t extent_size; /* Data extent size; default is 4096 */
232 size_t key_size;
233 size_t extent_shift;
234 unsigned int extent_mask;
235 struct ecryptfs_mount_crypt_stat *mount_crypt_stat;
236 struct crypto_skcipher *tfm;
237 struct crypto_shash *hash_tfm; /* Crypto context for generating
238 * the initialization vectors */
239 unsigned char cipher[ECRYPTFS_MAX_CIPHER_NAME_SIZE + 1];
240 unsigned char key[ECRYPTFS_MAX_KEY_BYTES];
241 unsigned char root_iv[ECRYPTFS_MAX_IV_BYTES];
242 struct list_head keysig_list;
243 struct mutex keysig_list_mutex;
244 struct mutex cs_tfm_mutex;
245 struct mutex cs_mutex;
246};
247
248/* inode private data. */
249struct ecryptfs_inode_info {
250 struct inode vfs_inode;
251 struct inode *wii_inode;
252 struct mutex lower_file_mutex;
253 atomic_t lower_file_count;
254 struct file *lower_file;
255 struct ecryptfs_crypt_stat crypt_stat;
256};
257
258/* dentry private data. Each dentry must keep track of a lower
259 * vfsmount too. */
260struct ecryptfs_dentry_info {
261 struct path lower_path;
262 union {
263 struct ecryptfs_crypt_stat *crypt_stat;
264 struct rcu_head rcu;
265 };
266};
267
268/**
269 * ecryptfs_global_auth_tok - A key used to encrypt all new files under the mountpoint
270 * @flags: Status flags
271 * @mount_crypt_stat_list: These auth_toks hang off the mount-wide
272 * cryptographic context. Every time a new
273 * inode comes into existence, eCryptfs copies
274 * the auth_toks on that list to the set of
275 * auth_toks on the inode's crypt_stat
276 * @global_auth_tok_key: The key from the user's keyring for the sig
277 * @global_auth_tok: The key contents
278 * @sig: The key identifier
279 *
280 * ecryptfs_global_auth_tok structs refer to authentication token keys
281 * in the user keyring that apply to newly created files. A list of
282 * these objects hangs off of the mount_crypt_stat struct for any
283 * given eCryptfs mount. This struct maintains a reference to both the
284 * key contents and the key itself so that the key can be put on
285 * unmount.
286 */
287struct ecryptfs_global_auth_tok {
288#define ECRYPTFS_AUTH_TOK_INVALID 0x00000001
289#define ECRYPTFS_AUTH_TOK_FNEK 0x00000002
290 u32 flags;
291 struct list_head mount_crypt_stat_list;
292 struct key *global_auth_tok_key;
293 unsigned char sig[ECRYPTFS_SIG_SIZE_HEX + 1];
294};
295
296/**
297 * ecryptfs_key_tfm - Persistent key tfm
298 * @key_tfm: crypto API handle to the key
299 * @key_size: Key size in bytes
300 * @key_tfm_mutex: Mutex to ensure only one operation in eCryptfs is
301 * using the persistent TFM at any point in time
302 * @key_tfm_list: Handle to hang this off the module-wide TFM list
303 * @cipher_name: String name for the cipher for this TFM
304 *
305 * Typically, eCryptfs will use the same ciphers repeatedly throughout
306 * the course of its operations. In order to avoid unnecessarily
307 * destroying and initializing the same cipher repeatedly, eCryptfs
308 * keeps a list of crypto API contexts around to use when needed.
309 */
310struct ecryptfs_key_tfm {
311 struct crypto_skcipher *key_tfm;
312 size_t key_size;
313 struct mutex key_tfm_mutex;
314 struct list_head key_tfm_list;
315 unsigned char cipher_name[ECRYPTFS_MAX_CIPHER_NAME_SIZE + 1];
316};
317
318extern struct mutex key_tfm_list_mutex;
319
320/**
321 * This struct is to enable a mount-wide passphrase/salt combo. This
322 * is more or less a stopgap to provide similar functionality to other
323 * crypto filesystems like EncFS or CFS until full policy support is
324 * implemented in eCryptfs.
325 */
326struct ecryptfs_mount_crypt_stat {
327 /* Pointers to memory we do not own, do not free these */
328#define ECRYPTFS_PLAINTEXT_PASSTHROUGH_ENABLED 0x00000001
329#define ECRYPTFS_XATTR_METADATA_ENABLED 0x00000002
330#define ECRYPTFS_ENCRYPTED_VIEW_ENABLED 0x00000004
331#define ECRYPTFS_MOUNT_CRYPT_STAT_INITIALIZED 0x00000008
332#define ECRYPTFS_GLOBAL_ENCRYPT_FILENAMES 0x00000010
333#define ECRYPTFS_GLOBAL_ENCFN_USE_MOUNT_FNEK 0x00000020
334#define ECRYPTFS_GLOBAL_ENCFN_USE_FEK 0x00000040
335#define ECRYPTFS_GLOBAL_MOUNT_AUTH_TOK_ONLY 0x00000080
336 u32 flags;
337 struct list_head global_auth_tok_list;
338 struct mutex global_auth_tok_list_mutex;
339 size_t global_default_cipher_key_size;
340 size_t global_default_fn_cipher_key_bytes;
341 unsigned char global_default_cipher_name[ECRYPTFS_MAX_CIPHER_NAME_SIZE
342 + 1];
343 unsigned char global_default_fn_cipher_name[
344 ECRYPTFS_MAX_CIPHER_NAME_SIZE + 1];
345 char global_default_fnek_sig[ECRYPTFS_SIG_SIZE_HEX + 1];
346};
347
348/* superblock private data. */
349struct ecryptfs_sb_info {
350 struct super_block *wsi_sb;
351 struct ecryptfs_mount_crypt_stat mount_crypt_stat;
352 struct backing_dev_info bdi;
353};
354
355/* file private data. */
356struct ecryptfs_file_info {
357 struct file *wfi_file;
358 struct ecryptfs_crypt_stat *crypt_stat;
359};
360
361/* auth_tok <=> encrypted_session_key mappings */
362struct ecryptfs_auth_tok_list_item {
363 unsigned char encrypted_session_key[ECRYPTFS_MAX_KEY_BYTES];
364 struct list_head list;
365 struct ecryptfs_auth_tok auth_tok;
366};
367
368struct ecryptfs_message {
369 /* Can never be greater than ecryptfs_message_buf_len */
370 /* Used to find the parent msg_ctx */
371 /* Inherits from msg_ctx->index */
372 u32 index;
373 u32 data_len;
374 u8 data[];
375};
376
377struct ecryptfs_msg_ctx {
378#define ECRYPTFS_MSG_CTX_STATE_FREE 0x01
379#define ECRYPTFS_MSG_CTX_STATE_PENDING 0x02
380#define ECRYPTFS_MSG_CTX_STATE_DONE 0x03
381#define ECRYPTFS_MSG_CTX_STATE_NO_REPLY 0x04
382 u8 state;
383#define ECRYPTFS_MSG_HELO 100
384#define ECRYPTFS_MSG_QUIT 101
385#define ECRYPTFS_MSG_REQUEST 102
386#define ECRYPTFS_MSG_RESPONSE 103
387 u8 type;
388 u32 index;
389 /* Counter converts to a sequence number. Each message sent
390 * out for which we expect a response has an associated
391 * sequence number. The response must have the same sequence
392 * number as the counter for the msg_stc for the message to be
393 * valid. */
394 u32 counter;
395 size_t msg_size;
396 struct ecryptfs_message *msg;
397 struct task_struct *task;
398 struct list_head node;
399 struct list_head daemon_out_list;
400 struct mutex mux;
401};
402
403struct ecryptfs_daemon {
404#define ECRYPTFS_DAEMON_IN_READ 0x00000001
405#define ECRYPTFS_DAEMON_IN_POLL 0x00000002
406#define ECRYPTFS_DAEMON_ZOMBIE 0x00000004
407#define ECRYPTFS_DAEMON_MISCDEV_OPEN 0x00000008
408 u32 flags;
409 u32 num_queued_msg_ctx;
410 struct file *file;
411 struct mutex mux;
412 struct list_head msg_ctx_out_queue;
413 wait_queue_head_t wait;
414 struct hlist_node euid_chain;
415};
416
417#ifdef CONFIG_ECRYPT_FS_MESSAGING
418extern struct mutex ecryptfs_daemon_hash_mux;
419#endif
420
421static inline size_t
422ecryptfs_lower_header_size(struct ecryptfs_crypt_stat *crypt_stat)
423{
424 if (crypt_stat->flags & ECRYPTFS_METADATA_IN_XATTR)
425 return 0;
426 return crypt_stat->metadata_size;
427}
428
429static inline struct ecryptfs_file_info *
430ecryptfs_file_to_private(struct file *file)
431{
432 return file->private_data;
433}
434
435static inline void
436ecryptfs_set_file_private(struct file *file,
437 struct ecryptfs_file_info *file_info)
438{
439 file->private_data = file_info;
440}
441
442static inline struct file *ecryptfs_file_to_lower(struct file *file)
443{
444 return ((struct ecryptfs_file_info *)file->private_data)->wfi_file;
445}
446
447static inline void
448ecryptfs_set_file_lower(struct file *file, struct file *lower_file)
449{
450 ((struct ecryptfs_file_info *)file->private_data)->wfi_file =
451 lower_file;
452}
453
454static inline struct ecryptfs_inode_info *
455ecryptfs_inode_to_private(struct inode *inode)
456{
457 return container_of(inode, struct ecryptfs_inode_info, vfs_inode);
458}
459
460static inline struct inode *ecryptfs_inode_to_lower(struct inode *inode)
461{
462 return ecryptfs_inode_to_private(inode)->wii_inode;
463}
464
465static inline void
466ecryptfs_set_inode_lower(struct inode *inode, struct inode *lower_inode)
467{
468 ecryptfs_inode_to_private(inode)->wii_inode = lower_inode;
469}
470
471static inline struct ecryptfs_sb_info *
472ecryptfs_superblock_to_private(struct super_block *sb)
473{
474 return (struct ecryptfs_sb_info *)sb->s_fs_info;
475}
476
477static inline void
478ecryptfs_set_superblock_private(struct super_block *sb,
479 struct ecryptfs_sb_info *sb_info)
480{
481 sb->s_fs_info = sb_info;
482}
483
484static inline struct super_block *
485ecryptfs_superblock_to_lower(struct super_block *sb)
486{
487 return ((struct ecryptfs_sb_info *)sb->s_fs_info)->wsi_sb;
488}
489
490static inline void
491ecryptfs_set_superblock_lower(struct super_block *sb,
492 struct super_block *lower_sb)
493{
494 ((struct ecryptfs_sb_info *)sb->s_fs_info)->wsi_sb = lower_sb;
495}
496
497static inline struct ecryptfs_dentry_info *
498ecryptfs_dentry_to_private(struct dentry *dentry)
499{
500 return (struct ecryptfs_dentry_info *)dentry->d_fsdata;
501}
502
503static inline void
504ecryptfs_set_dentry_private(struct dentry *dentry,
505 struct ecryptfs_dentry_info *dentry_info)
506{
507 dentry->d_fsdata = dentry_info;
508}
509
510static inline struct dentry *
511ecryptfs_dentry_to_lower(struct dentry *dentry)
512{
513 return ((struct ecryptfs_dentry_info *)dentry->d_fsdata)->lower_path.dentry;
514}
515
516static inline struct vfsmount *
517ecryptfs_dentry_to_lower_mnt(struct dentry *dentry)
518{
519 return ((struct ecryptfs_dentry_info *)dentry->d_fsdata)->lower_path.mnt;
520}
521
522static inline struct path *
523ecryptfs_dentry_to_lower_path(struct dentry *dentry)
524{
525 return &((struct ecryptfs_dentry_info *)dentry->d_fsdata)->lower_path;
526}
527
528#define ecryptfs_printk(type, fmt, arg...) \
529 __ecryptfs_printk(type "%s: " fmt, __func__, ## arg);
530__printf(1, 2)
531void __ecryptfs_printk(const char *fmt, ...);
532
533extern const struct file_operations ecryptfs_main_fops;
534extern const struct file_operations ecryptfs_dir_fops;
535extern const struct inode_operations ecryptfs_main_iops;
536extern const struct inode_operations ecryptfs_dir_iops;
537extern const struct inode_operations ecryptfs_symlink_iops;
538extern const struct super_operations ecryptfs_sops;
539extern const struct dentry_operations ecryptfs_dops;
540extern const struct address_space_operations ecryptfs_aops;
541extern int ecryptfs_verbosity;
542extern unsigned int ecryptfs_message_buf_len;
543extern signed long ecryptfs_message_wait_timeout;
544extern unsigned int ecryptfs_number_of_users;
545
546extern struct kmem_cache *ecryptfs_auth_tok_list_item_cache;
547extern struct kmem_cache *ecryptfs_file_info_cache;
548extern struct kmem_cache *ecryptfs_dentry_info_cache;
549extern struct kmem_cache *ecryptfs_inode_info_cache;
550extern struct kmem_cache *ecryptfs_sb_info_cache;
551extern struct kmem_cache *ecryptfs_header_cache;
552extern struct kmem_cache *ecryptfs_xattr_cache;
553extern struct kmem_cache *ecryptfs_key_record_cache;
554extern struct kmem_cache *ecryptfs_key_sig_cache;
555extern struct kmem_cache *ecryptfs_global_auth_tok_cache;
556extern struct kmem_cache *ecryptfs_key_tfm_cache;
557
558struct inode *ecryptfs_get_inode(struct inode *lower_inode,
559 struct super_block *sb);
560void ecryptfs_i_size_init(const char *page_virt, struct inode *inode);
561int ecryptfs_initialize_file(struct dentry *ecryptfs_dentry,
562 struct inode *ecryptfs_inode);
563int ecryptfs_decode_and_decrypt_filename(char **decrypted_name,
564 size_t *decrypted_name_size,
565 struct super_block *sb,
566 const char *name, size_t name_size);
567int ecryptfs_fill_zeros(struct file *file, loff_t new_length);
568int ecryptfs_encrypt_and_encode_filename(
569 char **encoded_name,
570 size_t *encoded_name_size,
571 struct ecryptfs_mount_crypt_stat *mount_crypt_stat,
572 const char *name, size_t name_size);
573struct dentry *ecryptfs_lower_dentry(struct dentry *this_dentry);
574void ecryptfs_dump_hex(char *data, int bytes);
575int virt_to_scatterlist(const void *addr, int size, struct scatterlist *sg,
576 int sg_size);
577int ecryptfs_compute_root_iv(struct ecryptfs_crypt_stat *crypt_stat);
578void ecryptfs_rotate_iv(unsigned char *iv);
579int ecryptfs_init_crypt_stat(struct ecryptfs_crypt_stat *crypt_stat);
580void ecryptfs_destroy_crypt_stat(struct ecryptfs_crypt_stat *crypt_stat);
581void ecryptfs_destroy_mount_crypt_stat(
582 struct ecryptfs_mount_crypt_stat *mount_crypt_stat);
583int ecryptfs_init_crypt_ctx(struct ecryptfs_crypt_stat *crypt_stat);
584int ecryptfs_write_inode_size_to_metadata(struct inode *ecryptfs_inode);
585int ecryptfs_encrypt_page(struct page *page);
586int ecryptfs_decrypt_page(struct page *page);
587int ecryptfs_write_metadata(struct dentry *ecryptfs_dentry,
588 struct inode *ecryptfs_inode);
589int ecryptfs_read_metadata(struct dentry *ecryptfs_dentry);
590int ecryptfs_new_file_context(struct inode *ecryptfs_inode);
591void ecryptfs_write_crypt_stat_flags(char *page_virt,
592 struct ecryptfs_crypt_stat *crypt_stat,
593 size_t *written);
594int ecryptfs_read_and_validate_header_region(struct inode *inode);
595int ecryptfs_read_and_validate_xattr_region(struct dentry *dentry,
596 struct inode *inode);
597u8 ecryptfs_code_for_cipher_string(char *cipher_name, size_t key_bytes);
598int ecryptfs_cipher_code_to_string(char *str, u8 cipher_code);
599void ecryptfs_set_default_sizes(struct ecryptfs_crypt_stat *crypt_stat);
600int ecryptfs_generate_key_packet_set(char *dest_base,
601 struct ecryptfs_crypt_stat *crypt_stat,
602 struct dentry *ecryptfs_dentry,
603 size_t *len, size_t max);
604int
605ecryptfs_parse_packet_set(struct ecryptfs_crypt_stat *crypt_stat,
606 unsigned char *src, struct dentry *ecryptfs_dentry);
607int ecryptfs_truncate(struct dentry *dentry, loff_t new_length);
608ssize_t
609ecryptfs_getxattr_lower(struct dentry *lower_dentry, struct inode *lower_inode,
610 const char *name, void *value, size_t size);
611int
612ecryptfs_setxattr(struct dentry *dentry, struct inode *inode, const char *name,
613 const void *value, size_t size, int flags);
614int ecryptfs_read_xattr_region(char *page_virt, struct inode *ecryptfs_inode);
615#ifdef CONFIG_ECRYPT_FS_MESSAGING
616int ecryptfs_process_response(struct ecryptfs_daemon *daemon,
617 struct ecryptfs_message *msg, u32 seq);
618int ecryptfs_send_message(char *data, int data_len,
619 struct ecryptfs_msg_ctx **msg_ctx);
620int ecryptfs_wait_for_response(struct ecryptfs_msg_ctx *msg_ctx,
621 struct ecryptfs_message **emsg);
622int ecryptfs_init_messaging(void);
623void ecryptfs_release_messaging(void);
624#else
625static inline int ecryptfs_init_messaging(void)
626{
627 return 0;
628}
629static inline void ecryptfs_release_messaging(void)
630{ }
631static inline int ecryptfs_send_message(char *data, int data_len,
632 struct ecryptfs_msg_ctx **msg_ctx)
633{
634 return -ENOTCONN;
635}
636static inline int ecryptfs_wait_for_response(struct ecryptfs_msg_ctx *msg_ctx,
637 struct ecryptfs_message **emsg)
638{
639 return -ENOMSG;
640}
641#endif
642
643void
644ecryptfs_write_header_metadata(char *virt,
645 struct ecryptfs_crypt_stat *crypt_stat,
646 size_t *written);
647int ecryptfs_add_keysig(struct ecryptfs_crypt_stat *crypt_stat, char *sig);
648int
649ecryptfs_add_global_auth_tok(struct ecryptfs_mount_crypt_stat *mount_crypt_stat,
650 char *sig, u32 global_auth_tok_flags);
651int ecryptfs_get_global_auth_tok_for_sig(
652 struct ecryptfs_global_auth_tok **global_auth_tok,
653 struct ecryptfs_mount_crypt_stat *mount_crypt_stat, char *sig);
654int
655ecryptfs_add_new_key_tfm(struct ecryptfs_key_tfm **key_tfm, char *cipher_name,
656 size_t key_size);
657int ecryptfs_init_crypto(void);
658int ecryptfs_destroy_crypto(void);
659int ecryptfs_tfm_exists(char *cipher_name, struct ecryptfs_key_tfm **key_tfm);
660int ecryptfs_get_tfm_and_mutex_for_cipher_name(struct crypto_skcipher **tfm,
661 struct mutex **tfm_mutex,
662 char *cipher_name);
663int ecryptfs_keyring_auth_tok_for_sig(struct key **auth_tok_key,
664 struct ecryptfs_auth_tok **auth_tok,
665 char *sig);
666int ecryptfs_write_lower(struct inode *ecryptfs_inode, char *data,
667 loff_t offset, size_t size);
668int ecryptfs_write_lower_page_segment(struct inode *ecryptfs_inode,
669 struct page *page_for_lower,
670 size_t offset_in_page, size_t size);
671int ecryptfs_write(struct inode *inode, char *data, loff_t offset, size_t size);
672int ecryptfs_read_lower(char *data, loff_t offset, size_t size,
673 struct inode *ecryptfs_inode);
674int ecryptfs_read_lower_page_segment(struct page *page_for_ecryptfs,
675 pgoff_t page_index,
676 size_t offset_in_page, size_t size,
677 struct inode *ecryptfs_inode);
678struct page *ecryptfs_get_locked_page(struct inode *inode, loff_t index);
679int ecryptfs_parse_packet_length(unsigned char *data, size_t *size,
680 size_t *length_size);
681int ecryptfs_write_packet_length(char *dest, size_t size,
682 size_t *packet_size_length);
683#ifdef CONFIG_ECRYPT_FS_MESSAGING
684int ecryptfs_init_ecryptfs_miscdev(void);
685void ecryptfs_destroy_ecryptfs_miscdev(void);
686int ecryptfs_send_miscdev(char *data, size_t data_size,
687 struct ecryptfs_msg_ctx *msg_ctx, u8 msg_type,
688 u16 msg_flags, struct ecryptfs_daemon *daemon);
689void ecryptfs_msg_ctx_alloc_to_free(struct ecryptfs_msg_ctx *msg_ctx);
690int
691ecryptfs_spawn_daemon(struct ecryptfs_daemon **daemon, struct file *file);
692int ecryptfs_exorcise_daemon(struct ecryptfs_daemon *daemon);
693int ecryptfs_find_daemon_by_euid(struct ecryptfs_daemon **daemon);
694#endif
695int ecryptfs_init_kthread(void);
696void ecryptfs_destroy_kthread(void);
697int ecryptfs_privileged_open(struct file **lower_file,
698 struct dentry *lower_dentry,
699 struct vfsmount *lower_mnt,
700 const struct cred *cred);
701int ecryptfs_get_lower_file(struct dentry *dentry, struct inode *inode);
702void ecryptfs_put_lower_file(struct inode *inode);
703int
704ecryptfs_write_tag_70_packet(char *dest, size_t *remaining_bytes,
705 size_t *packet_size,
706 struct ecryptfs_mount_crypt_stat *mount_crypt_stat,
707 char *filename, size_t filename_size);
708int
709ecryptfs_parse_tag_70_packet(char **filename, size_t *filename_size,
710 size_t *packet_size,
711 struct ecryptfs_mount_crypt_stat *mount_crypt_stat,
712 char *data, size_t max_packet_size);
713int ecryptfs_set_f_namelen(long *namelen, long lower_namelen,
714 struct ecryptfs_mount_crypt_stat *mount_crypt_stat);
715int ecryptfs_derive_iv(char *iv, struct ecryptfs_crypt_stat *crypt_stat,
716 loff_t offset);
717
718extern const struct xattr_handler *ecryptfs_xattr_handlers[];
719
720#endif /* #ifndef ECRYPTFS_KERNEL_H */
1/* SPDX-License-Identifier: GPL-2.0-or-later */
2/**
3 * eCryptfs: Linux filesystem encryption layer
4 * Kernel declarations.
5 *
6 * Copyright (C) 1997-2003 Erez Zadok
7 * Copyright (C) 2001-2003 Stony Brook University
8 * Copyright (C) 2004-2008 International Business Machines Corp.
9 * Author(s): Michael A. Halcrow <mahalcro@us.ibm.com>
10 * Trevor S. Highland <trevor.highland@gmail.com>
11 * Tyler Hicks <code@tyhicks.com>
12 */
13
14#ifndef ECRYPTFS_KERNEL_H
15#define ECRYPTFS_KERNEL_H
16
17#include <crypto/skcipher.h>
18#include <keys/user-type.h>
19#include <keys/encrypted-type.h>
20#include <linux/kernel.h>
21#include <linux/fs.h>
22#include <linux/fs_stack.h>
23#include <linux/namei.h>
24#include <linux/scatterlist.h>
25#include <linux/hash.h>
26#include <linux/nsproxy.h>
27#include <linux/backing-dev.h>
28#include <linux/ecryptfs.h>
29
30#define ECRYPTFS_DEFAULT_IV_BYTES 16
31#define ECRYPTFS_DEFAULT_EXTENT_SIZE 4096
32#define ECRYPTFS_MINIMUM_HEADER_EXTENT_SIZE 8192
33#define ECRYPTFS_DEFAULT_MSG_CTX_ELEMS 32
34#define ECRYPTFS_DEFAULT_SEND_TIMEOUT HZ
35#define ECRYPTFS_MAX_MSG_CTX_TTL (HZ*3)
36#define ECRYPTFS_DEFAULT_NUM_USERS 4
37#define ECRYPTFS_MAX_NUM_USERS 32768
38#define ECRYPTFS_XATTR_NAME "user.ecryptfs"
39
40void ecryptfs_dump_auth_tok(struct ecryptfs_auth_tok *auth_tok);
41static inline void
42ecryptfs_to_hex(char *dst, char *src, size_t src_size)
43{
44 char *end = bin2hex(dst, src, src_size);
45 *end = '\0';
46}
47
48extern void ecryptfs_from_hex(char *dst, char *src, int dst_size);
49
50struct ecryptfs_key_record {
51 unsigned char type;
52 size_t enc_key_size;
53 unsigned char sig[ECRYPTFS_SIG_SIZE];
54 unsigned char enc_key[ECRYPTFS_MAX_ENCRYPTED_KEY_BYTES];
55};
56
57struct ecryptfs_auth_tok_list {
58 struct ecryptfs_auth_tok *auth_tok;
59 struct list_head list;
60};
61
62struct ecryptfs_crypt_stat;
63struct ecryptfs_mount_crypt_stat;
64
65struct ecryptfs_page_crypt_context {
66 struct page *page;
67#define ECRYPTFS_PREPARE_COMMIT_MODE 0
68#define ECRYPTFS_WRITEPAGE_MODE 1
69 unsigned int mode;
70 union {
71 struct file *lower_file;
72 struct writeback_control *wbc;
73 } param;
74};
75
76#if defined(CONFIG_ENCRYPTED_KEYS) || defined(CONFIG_ENCRYPTED_KEYS_MODULE)
77static inline struct ecryptfs_auth_tok *
78ecryptfs_get_encrypted_key_payload_data(struct key *key)
79{
80 struct encrypted_key_payload *payload;
81
82 if (key->type != &key_type_encrypted)
83 return NULL;
84
85 payload = key->payload.data[0];
86 if (!payload)
87 return ERR_PTR(-EKEYREVOKED);
88
89 return (struct ecryptfs_auth_tok *)payload->payload_data;
90}
91
92static inline struct key *ecryptfs_get_encrypted_key(char *sig)
93{
94 return request_key(&key_type_encrypted, sig, NULL);
95}
96
97#else
98static inline struct ecryptfs_auth_tok *
99ecryptfs_get_encrypted_key_payload_data(struct key *key)
100{
101 return NULL;
102}
103
104static inline struct key *ecryptfs_get_encrypted_key(char *sig)
105{
106 return ERR_PTR(-ENOKEY);
107}
108
109#endif /* CONFIG_ENCRYPTED_KEYS */
110
111static inline struct ecryptfs_auth_tok *
112ecryptfs_get_key_payload_data(struct key *key)
113{
114 struct ecryptfs_auth_tok *auth_tok;
115 struct user_key_payload *ukp;
116
117 auth_tok = ecryptfs_get_encrypted_key_payload_data(key);
118 if (auth_tok)
119 return auth_tok;
120
121 ukp = user_key_payload_locked(key);
122 if (!ukp)
123 return ERR_PTR(-EKEYREVOKED);
124
125 return (struct ecryptfs_auth_tok *)ukp->data;
126}
127
128#define ECRYPTFS_MAX_KEYSET_SIZE 1024
129#define ECRYPTFS_MAX_CIPHER_NAME_SIZE 31
130#define ECRYPTFS_MAX_NUM_ENC_KEYS 64
131#define ECRYPTFS_MAX_IV_BYTES 16 /* 128 bits */
132#define ECRYPTFS_SALT_BYTES 2
133#define MAGIC_ECRYPTFS_MARKER 0x3c81b7f5
134#define MAGIC_ECRYPTFS_MARKER_SIZE_BYTES 8 /* 4*2 */
135#define ECRYPTFS_FILE_SIZE_BYTES (sizeof(u64))
136#define ECRYPTFS_SIZE_AND_MARKER_BYTES (ECRYPTFS_FILE_SIZE_BYTES \
137 + MAGIC_ECRYPTFS_MARKER_SIZE_BYTES)
138#define ECRYPTFS_DEFAULT_CIPHER "aes"
139#define ECRYPTFS_DEFAULT_KEY_BYTES 16
140#define ECRYPTFS_DEFAULT_HASH "md5"
141#define ECRYPTFS_TAG_70_DIGEST ECRYPTFS_DEFAULT_HASH
142#define ECRYPTFS_TAG_1_PACKET_TYPE 0x01
143#define ECRYPTFS_TAG_3_PACKET_TYPE 0x8C
144#define ECRYPTFS_TAG_11_PACKET_TYPE 0xED
145#define ECRYPTFS_TAG_64_PACKET_TYPE 0x40
146#define ECRYPTFS_TAG_65_PACKET_TYPE 0x41
147#define ECRYPTFS_TAG_66_PACKET_TYPE 0x42
148#define ECRYPTFS_TAG_67_PACKET_TYPE 0x43
149#define ECRYPTFS_TAG_70_PACKET_TYPE 0x46 /* FNEK-encrypted filename
150 * as dentry name */
151#define ECRYPTFS_TAG_71_PACKET_TYPE 0x47 /* FNEK-encrypted filename in
152 * metadata */
153#define ECRYPTFS_TAG_72_PACKET_TYPE 0x48 /* FEK-encrypted filename as
154 * dentry name */
155#define ECRYPTFS_TAG_73_PACKET_TYPE 0x49 /* FEK-encrypted filename as
156 * metadata */
157#define ECRYPTFS_MIN_PKT_LEN_SIZE 1 /* Min size to specify packet length */
158#define ECRYPTFS_MAX_PKT_LEN_SIZE 2 /* Pass at least this many bytes to
159 * ecryptfs_parse_packet_length() and
160 * ecryptfs_write_packet_length()
161 */
162/* Constraint: ECRYPTFS_FILENAME_MIN_RANDOM_PREPEND_BYTES >=
163 * ECRYPTFS_MAX_IV_BYTES */
164#define ECRYPTFS_FILENAME_MIN_RANDOM_PREPEND_BYTES 16
165#define ECRYPTFS_NON_NULL 0x42 /* A reasonable substitute for NULL */
166#define MD5_DIGEST_SIZE 16
167#define ECRYPTFS_TAG_70_DIGEST_SIZE MD5_DIGEST_SIZE
168#define ECRYPTFS_TAG_70_MIN_METADATA_SIZE (1 + ECRYPTFS_MIN_PKT_LEN_SIZE \
169 + ECRYPTFS_SIG_SIZE + 1 + 1)
170#define ECRYPTFS_TAG_70_MAX_METADATA_SIZE (1 + ECRYPTFS_MAX_PKT_LEN_SIZE \
171 + ECRYPTFS_SIG_SIZE + 1 + 1)
172#define ECRYPTFS_FEK_ENCRYPTED_FILENAME_PREFIX "ECRYPTFS_FEK_ENCRYPTED."
173#define ECRYPTFS_FEK_ENCRYPTED_FILENAME_PREFIX_SIZE 23
174#define ECRYPTFS_FNEK_ENCRYPTED_FILENAME_PREFIX "ECRYPTFS_FNEK_ENCRYPTED."
175#define ECRYPTFS_FNEK_ENCRYPTED_FILENAME_PREFIX_SIZE 24
176#define ECRYPTFS_ENCRYPTED_DENTRY_NAME_LEN (18 + 1 + 4 + 1 + 32)
177
178#ifdef CONFIG_ECRYPT_FS_MESSAGING
179# define ECRYPTFS_VERSIONING_MASK_MESSAGING (ECRYPTFS_VERSIONING_DEVMISC \
180 | ECRYPTFS_VERSIONING_PUBKEY)
181#else
182# define ECRYPTFS_VERSIONING_MASK_MESSAGING 0
183#endif
184
185#define ECRYPTFS_VERSIONING_MASK (ECRYPTFS_VERSIONING_PASSPHRASE \
186 | ECRYPTFS_VERSIONING_PLAINTEXT_PASSTHROUGH \
187 | ECRYPTFS_VERSIONING_XATTR \
188 | ECRYPTFS_VERSIONING_MULTKEY \
189 | ECRYPTFS_VERSIONING_MASK_MESSAGING \
190 | ECRYPTFS_VERSIONING_FILENAME_ENCRYPTION)
191struct ecryptfs_key_sig {
192 struct list_head crypt_stat_list;
193 char keysig[ECRYPTFS_SIG_SIZE_HEX + 1];
194};
195
196struct ecryptfs_filename {
197 struct list_head crypt_stat_list;
198#define ECRYPTFS_FILENAME_CONTAINS_DECRYPTED 0x00000001
199 u32 flags;
200 u32 seq_no;
201 char *filename;
202 char *encrypted_filename;
203 size_t filename_size;
204 size_t encrypted_filename_size;
205 char fnek_sig[ECRYPTFS_SIG_SIZE_HEX];
206 char dentry_name[ECRYPTFS_ENCRYPTED_DENTRY_NAME_LEN + 1];
207};
208
209/**
210 * This is the primary struct associated with each encrypted file.
211 *
212 * TODO: cache align/pack?
213 */
214struct ecryptfs_crypt_stat {
215#define ECRYPTFS_STRUCT_INITIALIZED 0x00000001
216#define ECRYPTFS_POLICY_APPLIED 0x00000002
217#define ECRYPTFS_ENCRYPTED 0x00000004
218#define ECRYPTFS_SECURITY_WARNING 0x00000008
219#define ECRYPTFS_ENABLE_HMAC 0x00000010
220#define ECRYPTFS_ENCRYPT_IV_PAGES 0x00000020
221#define ECRYPTFS_KEY_VALID 0x00000040
222#define ECRYPTFS_METADATA_IN_XATTR 0x00000080
223#define ECRYPTFS_VIEW_AS_ENCRYPTED 0x00000100
224#define ECRYPTFS_KEY_SET 0x00000200
225#define ECRYPTFS_ENCRYPT_FILENAMES 0x00000400
226#define ECRYPTFS_ENCFN_USE_MOUNT_FNEK 0x00000800
227#define ECRYPTFS_ENCFN_USE_FEK 0x00001000
228#define ECRYPTFS_UNLINK_SIGS 0x00002000
229#define ECRYPTFS_I_SIZE_INITIALIZED 0x00004000
230 u32 flags;
231 unsigned int file_version;
232 size_t iv_bytes;
233 size_t metadata_size;
234 size_t extent_size; /* Data extent size; default is 4096 */
235 size_t key_size;
236 size_t extent_shift;
237 unsigned int extent_mask;
238 struct ecryptfs_mount_crypt_stat *mount_crypt_stat;
239 struct crypto_skcipher *tfm;
240 struct crypto_shash *hash_tfm; /* Crypto context for generating
241 * the initialization vectors */
242 unsigned char cipher[ECRYPTFS_MAX_CIPHER_NAME_SIZE + 1];
243 unsigned char key[ECRYPTFS_MAX_KEY_BYTES];
244 unsigned char root_iv[ECRYPTFS_MAX_IV_BYTES];
245 struct list_head keysig_list;
246 struct mutex keysig_list_mutex;
247 struct mutex cs_tfm_mutex;
248 struct mutex cs_mutex;
249};
250
251/* inode private data. */
252struct ecryptfs_inode_info {
253 struct inode vfs_inode;
254 struct inode *wii_inode;
255 struct mutex lower_file_mutex;
256 atomic_t lower_file_count;
257 struct file *lower_file;
258 struct ecryptfs_crypt_stat crypt_stat;
259};
260
261/* dentry private data. Each dentry must keep track of a lower
262 * vfsmount too. */
263struct ecryptfs_dentry_info {
264 struct path lower_path;
265 union {
266 struct ecryptfs_crypt_stat *crypt_stat;
267 struct rcu_head rcu;
268 };
269};
270
271/**
272 * ecryptfs_global_auth_tok - A key used to encrypt all new files under the mountpoint
273 * @flags: Status flags
274 * @mount_crypt_stat_list: These auth_toks hang off the mount-wide
275 * cryptographic context. Every time a new
276 * inode comes into existence, eCryptfs copies
277 * the auth_toks on that list to the set of
278 * auth_toks on the inode's crypt_stat
279 * @global_auth_tok_key: The key from the user's keyring for the sig
280 * @global_auth_tok: The key contents
281 * @sig: The key identifier
282 *
283 * ecryptfs_global_auth_tok structs refer to authentication token keys
284 * in the user keyring that apply to newly created files. A list of
285 * these objects hangs off of the mount_crypt_stat struct for any
286 * given eCryptfs mount. This struct maintains a reference to both the
287 * key contents and the key itself so that the key can be put on
288 * unmount.
289 */
290struct ecryptfs_global_auth_tok {
291#define ECRYPTFS_AUTH_TOK_INVALID 0x00000001
292#define ECRYPTFS_AUTH_TOK_FNEK 0x00000002
293 u32 flags;
294 struct list_head mount_crypt_stat_list;
295 struct key *global_auth_tok_key;
296 unsigned char sig[ECRYPTFS_SIG_SIZE_HEX + 1];
297};
298
299/**
300 * ecryptfs_key_tfm - Persistent key tfm
301 * @key_tfm: crypto API handle to the key
302 * @key_size: Key size in bytes
303 * @key_tfm_mutex: Mutex to ensure only one operation in eCryptfs is
304 * using the persistent TFM at any point in time
305 * @key_tfm_list: Handle to hang this off the module-wide TFM list
306 * @cipher_name: String name for the cipher for this TFM
307 *
308 * Typically, eCryptfs will use the same ciphers repeatedly throughout
309 * the course of its operations. In order to avoid unnecessarily
310 * destroying and initializing the same cipher repeatedly, eCryptfs
311 * keeps a list of crypto API contexts around to use when needed.
312 */
313struct ecryptfs_key_tfm {
314 struct crypto_skcipher *key_tfm;
315 size_t key_size;
316 struct mutex key_tfm_mutex;
317 struct list_head key_tfm_list;
318 unsigned char cipher_name[ECRYPTFS_MAX_CIPHER_NAME_SIZE + 1];
319};
320
321extern struct mutex key_tfm_list_mutex;
322
323/**
324 * This struct is to enable a mount-wide passphrase/salt combo. This
325 * is more or less a stopgap to provide similar functionality to other
326 * crypto filesystems like EncFS or CFS until full policy support is
327 * implemented in eCryptfs.
328 */
329struct ecryptfs_mount_crypt_stat {
330 /* Pointers to memory we do not own, do not free these */
331#define ECRYPTFS_PLAINTEXT_PASSTHROUGH_ENABLED 0x00000001
332#define ECRYPTFS_XATTR_METADATA_ENABLED 0x00000002
333#define ECRYPTFS_ENCRYPTED_VIEW_ENABLED 0x00000004
334#define ECRYPTFS_MOUNT_CRYPT_STAT_INITIALIZED 0x00000008
335#define ECRYPTFS_GLOBAL_ENCRYPT_FILENAMES 0x00000010
336#define ECRYPTFS_GLOBAL_ENCFN_USE_MOUNT_FNEK 0x00000020
337#define ECRYPTFS_GLOBAL_ENCFN_USE_FEK 0x00000040
338#define ECRYPTFS_GLOBAL_MOUNT_AUTH_TOK_ONLY 0x00000080
339 u32 flags;
340 struct list_head global_auth_tok_list;
341 struct mutex global_auth_tok_list_mutex;
342 size_t global_default_cipher_key_size;
343 size_t global_default_fn_cipher_key_bytes;
344 unsigned char global_default_cipher_name[ECRYPTFS_MAX_CIPHER_NAME_SIZE
345 + 1];
346 unsigned char global_default_fn_cipher_name[
347 ECRYPTFS_MAX_CIPHER_NAME_SIZE + 1];
348 char global_default_fnek_sig[ECRYPTFS_SIG_SIZE_HEX + 1];
349};
350
351/* superblock private data. */
352struct ecryptfs_sb_info {
353 struct super_block *wsi_sb;
354 struct ecryptfs_mount_crypt_stat mount_crypt_stat;
355};
356
357/* file private data. */
358struct ecryptfs_file_info {
359 struct file *wfi_file;
360 struct ecryptfs_crypt_stat *crypt_stat;
361};
362
363/* auth_tok <=> encrypted_session_key mappings */
364struct ecryptfs_auth_tok_list_item {
365 unsigned char encrypted_session_key[ECRYPTFS_MAX_KEY_BYTES];
366 struct list_head list;
367 struct ecryptfs_auth_tok auth_tok;
368};
369
370struct ecryptfs_message {
371 /* Can never be greater than ecryptfs_message_buf_len */
372 /* Used to find the parent msg_ctx */
373 /* Inherits from msg_ctx->index */
374 u32 index;
375 u32 data_len;
376 u8 data[];
377};
378
379struct ecryptfs_msg_ctx {
380#define ECRYPTFS_MSG_CTX_STATE_FREE 0x01
381#define ECRYPTFS_MSG_CTX_STATE_PENDING 0x02
382#define ECRYPTFS_MSG_CTX_STATE_DONE 0x03
383#define ECRYPTFS_MSG_CTX_STATE_NO_REPLY 0x04
384 u8 state;
385#define ECRYPTFS_MSG_HELO 100
386#define ECRYPTFS_MSG_QUIT 101
387#define ECRYPTFS_MSG_REQUEST 102
388#define ECRYPTFS_MSG_RESPONSE 103
389 u8 type;
390 u32 index;
391 /* Counter converts to a sequence number. Each message sent
392 * out for which we expect a response has an associated
393 * sequence number. The response must have the same sequence
394 * number as the counter for the msg_stc for the message to be
395 * valid. */
396 u32 counter;
397 size_t msg_size;
398 struct ecryptfs_message *msg;
399 struct task_struct *task;
400 struct list_head node;
401 struct list_head daemon_out_list;
402 struct mutex mux;
403};
404
405struct ecryptfs_daemon {
406#define ECRYPTFS_DAEMON_IN_READ 0x00000001
407#define ECRYPTFS_DAEMON_IN_POLL 0x00000002
408#define ECRYPTFS_DAEMON_ZOMBIE 0x00000004
409#define ECRYPTFS_DAEMON_MISCDEV_OPEN 0x00000008
410 u32 flags;
411 u32 num_queued_msg_ctx;
412 struct file *file;
413 struct mutex mux;
414 struct list_head msg_ctx_out_queue;
415 wait_queue_head_t wait;
416 struct hlist_node euid_chain;
417};
418
419#ifdef CONFIG_ECRYPT_FS_MESSAGING
420extern struct mutex ecryptfs_daemon_hash_mux;
421#endif
422
423static inline size_t
424ecryptfs_lower_header_size(struct ecryptfs_crypt_stat *crypt_stat)
425{
426 if (crypt_stat->flags & ECRYPTFS_METADATA_IN_XATTR)
427 return 0;
428 return crypt_stat->metadata_size;
429}
430
431static inline struct ecryptfs_file_info *
432ecryptfs_file_to_private(struct file *file)
433{
434 return file->private_data;
435}
436
437static inline void
438ecryptfs_set_file_private(struct file *file,
439 struct ecryptfs_file_info *file_info)
440{
441 file->private_data = file_info;
442}
443
444static inline struct file *ecryptfs_file_to_lower(struct file *file)
445{
446 return ((struct ecryptfs_file_info *)file->private_data)->wfi_file;
447}
448
449static inline void
450ecryptfs_set_file_lower(struct file *file, struct file *lower_file)
451{
452 ((struct ecryptfs_file_info *)file->private_data)->wfi_file =
453 lower_file;
454}
455
456static inline struct ecryptfs_inode_info *
457ecryptfs_inode_to_private(struct inode *inode)
458{
459 return container_of(inode, struct ecryptfs_inode_info, vfs_inode);
460}
461
462static inline struct inode *ecryptfs_inode_to_lower(struct inode *inode)
463{
464 return ecryptfs_inode_to_private(inode)->wii_inode;
465}
466
467static inline void
468ecryptfs_set_inode_lower(struct inode *inode, struct inode *lower_inode)
469{
470 ecryptfs_inode_to_private(inode)->wii_inode = lower_inode;
471}
472
473static inline struct ecryptfs_sb_info *
474ecryptfs_superblock_to_private(struct super_block *sb)
475{
476 return (struct ecryptfs_sb_info *)sb->s_fs_info;
477}
478
479static inline void
480ecryptfs_set_superblock_private(struct super_block *sb,
481 struct ecryptfs_sb_info *sb_info)
482{
483 sb->s_fs_info = sb_info;
484}
485
486static inline struct super_block *
487ecryptfs_superblock_to_lower(struct super_block *sb)
488{
489 return ((struct ecryptfs_sb_info *)sb->s_fs_info)->wsi_sb;
490}
491
492static inline void
493ecryptfs_set_superblock_lower(struct super_block *sb,
494 struct super_block *lower_sb)
495{
496 ((struct ecryptfs_sb_info *)sb->s_fs_info)->wsi_sb = lower_sb;
497}
498
499static inline struct ecryptfs_dentry_info *
500ecryptfs_dentry_to_private(struct dentry *dentry)
501{
502 return (struct ecryptfs_dentry_info *)dentry->d_fsdata;
503}
504
505static inline void
506ecryptfs_set_dentry_private(struct dentry *dentry,
507 struct ecryptfs_dentry_info *dentry_info)
508{
509 dentry->d_fsdata = dentry_info;
510}
511
512static inline struct dentry *
513ecryptfs_dentry_to_lower(struct dentry *dentry)
514{
515 return ((struct ecryptfs_dentry_info *)dentry->d_fsdata)->lower_path.dentry;
516}
517
518static inline struct vfsmount *
519ecryptfs_dentry_to_lower_mnt(struct dentry *dentry)
520{
521 return ((struct ecryptfs_dentry_info *)dentry->d_fsdata)->lower_path.mnt;
522}
523
524static inline struct path *
525ecryptfs_dentry_to_lower_path(struct dentry *dentry)
526{
527 return &((struct ecryptfs_dentry_info *)dentry->d_fsdata)->lower_path;
528}
529
530#define ecryptfs_printk(type, fmt, arg...) \
531 __ecryptfs_printk(type "%s: " fmt, __func__, ## arg);
532__printf(1, 2)
533void __ecryptfs_printk(const char *fmt, ...);
534
535extern const struct file_operations ecryptfs_main_fops;
536extern const struct file_operations ecryptfs_dir_fops;
537extern const struct inode_operations ecryptfs_main_iops;
538extern const struct inode_operations ecryptfs_dir_iops;
539extern const struct inode_operations ecryptfs_symlink_iops;
540extern const struct super_operations ecryptfs_sops;
541extern const struct dentry_operations ecryptfs_dops;
542extern const struct address_space_operations ecryptfs_aops;
543extern int ecryptfs_verbosity;
544extern unsigned int ecryptfs_message_buf_len;
545extern signed long ecryptfs_message_wait_timeout;
546extern unsigned int ecryptfs_number_of_users;
547
548extern struct kmem_cache *ecryptfs_auth_tok_list_item_cache;
549extern struct kmem_cache *ecryptfs_file_info_cache;
550extern struct kmem_cache *ecryptfs_dentry_info_cache;
551extern struct kmem_cache *ecryptfs_inode_info_cache;
552extern struct kmem_cache *ecryptfs_sb_info_cache;
553extern struct kmem_cache *ecryptfs_header_cache;
554extern struct kmem_cache *ecryptfs_xattr_cache;
555extern struct kmem_cache *ecryptfs_key_record_cache;
556extern struct kmem_cache *ecryptfs_key_sig_cache;
557extern struct kmem_cache *ecryptfs_global_auth_tok_cache;
558extern struct kmem_cache *ecryptfs_key_tfm_cache;
559
560struct inode *ecryptfs_get_inode(struct inode *lower_inode,
561 struct super_block *sb);
562void ecryptfs_i_size_init(const char *page_virt, struct inode *inode);
563int ecryptfs_initialize_file(struct dentry *ecryptfs_dentry,
564 struct inode *ecryptfs_inode);
565int ecryptfs_decode_and_decrypt_filename(char **decrypted_name,
566 size_t *decrypted_name_size,
567 struct super_block *sb,
568 const char *name, size_t name_size);
569int ecryptfs_fill_zeros(struct file *file, loff_t new_length);
570int ecryptfs_encrypt_and_encode_filename(
571 char **encoded_name,
572 size_t *encoded_name_size,
573 struct ecryptfs_mount_crypt_stat *mount_crypt_stat,
574 const char *name, size_t name_size);
575struct dentry *ecryptfs_lower_dentry(struct dentry *this_dentry);
576void ecryptfs_dump_hex(char *data, int bytes);
577int virt_to_scatterlist(const void *addr, int size, struct scatterlist *sg,
578 int sg_size);
579int ecryptfs_compute_root_iv(struct ecryptfs_crypt_stat *crypt_stat);
580void ecryptfs_rotate_iv(unsigned char *iv);
581int ecryptfs_init_crypt_stat(struct ecryptfs_crypt_stat *crypt_stat);
582void ecryptfs_destroy_crypt_stat(struct ecryptfs_crypt_stat *crypt_stat);
583void ecryptfs_destroy_mount_crypt_stat(
584 struct ecryptfs_mount_crypt_stat *mount_crypt_stat);
585int ecryptfs_init_crypt_ctx(struct ecryptfs_crypt_stat *crypt_stat);
586int ecryptfs_write_inode_size_to_metadata(struct inode *ecryptfs_inode);
587int ecryptfs_encrypt_page(struct page *page);
588int ecryptfs_decrypt_page(struct page *page);
589int ecryptfs_write_metadata(struct dentry *ecryptfs_dentry,
590 struct inode *ecryptfs_inode);
591int ecryptfs_read_metadata(struct dentry *ecryptfs_dentry);
592int ecryptfs_new_file_context(struct inode *ecryptfs_inode);
593void ecryptfs_write_crypt_stat_flags(char *page_virt,
594 struct ecryptfs_crypt_stat *crypt_stat,
595 size_t *written);
596int ecryptfs_read_and_validate_header_region(struct inode *inode);
597int ecryptfs_read_and_validate_xattr_region(struct dentry *dentry,
598 struct inode *inode);
599u8 ecryptfs_code_for_cipher_string(char *cipher_name, size_t key_bytes);
600int ecryptfs_cipher_code_to_string(char *str, u8 cipher_code);
601void ecryptfs_set_default_sizes(struct ecryptfs_crypt_stat *crypt_stat);
602int ecryptfs_generate_key_packet_set(char *dest_base,
603 struct ecryptfs_crypt_stat *crypt_stat,
604 struct dentry *ecryptfs_dentry,
605 size_t *len, size_t max);
606int
607ecryptfs_parse_packet_set(struct ecryptfs_crypt_stat *crypt_stat,
608 unsigned char *src, struct dentry *ecryptfs_dentry);
609int ecryptfs_truncate(struct dentry *dentry, loff_t new_length);
610ssize_t
611ecryptfs_getxattr_lower(struct dentry *lower_dentry, struct inode *lower_inode,
612 const char *name, void *value, size_t size);
613int
614ecryptfs_setxattr(struct dentry *dentry, struct inode *inode, const char *name,
615 const void *value, size_t size, int flags);
616int ecryptfs_read_xattr_region(char *page_virt, struct inode *ecryptfs_inode);
617#ifdef CONFIG_ECRYPT_FS_MESSAGING
618int ecryptfs_process_response(struct ecryptfs_daemon *daemon,
619 struct ecryptfs_message *msg, u32 seq);
620int ecryptfs_send_message(char *data, int data_len,
621 struct ecryptfs_msg_ctx **msg_ctx);
622int ecryptfs_wait_for_response(struct ecryptfs_msg_ctx *msg_ctx,
623 struct ecryptfs_message **emsg);
624int ecryptfs_init_messaging(void);
625void ecryptfs_release_messaging(void);
626#else
627static inline int ecryptfs_init_messaging(void)
628{
629 return 0;
630}
631static inline void ecryptfs_release_messaging(void)
632{ }
633static inline int ecryptfs_send_message(char *data, int data_len,
634 struct ecryptfs_msg_ctx **msg_ctx)
635{
636 return -ENOTCONN;
637}
638static inline int ecryptfs_wait_for_response(struct ecryptfs_msg_ctx *msg_ctx,
639 struct ecryptfs_message **emsg)
640{
641 return -ENOMSG;
642}
643#endif
644
645void
646ecryptfs_write_header_metadata(char *virt,
647 struct ecryptfs_crypt_stat *crypt_stat,
648 size_t *written);
649int ecryptfs_add_keysig(struct ecryptfs_crypt_stat *crypt_stat, char *sig);
650int
651ecryptfs_add_global_auth_tok(struct ecryptfs_mount_crypt_stat *mount_crypt_stat,
652 char *sig, u32 global_auth_tok_flags);
653int ecryptfs_get_global_auth_tok_for_sig(
654 struct ecryptfs_global_auth_tok **global_auth_tok,
655 struct ecryptfs_mount_crypt_stat *mount_crypt_stat, char *sig);
656int
657ecryptfs_add_new_key_tfm(struct ecryptfs_key_tfm **key_tfm, char *cipher_name,
658 size_t key_size);
659int ecryptfs_init_crypto(void);
660int ecryptfs_destroy_crypto(void);
661int ecryptfs_tfm_exists(char *cipher_name, struct ecryptfs_key_tfm **key_tfm);
662int ecryptfs_get_tfm_and_mutex_for_cipher_name(struct crypto_skcipher **tfm,
663 struct mutex **tfm_mutex,
664 char *cipher_name);
665int ecryptfs_keyring_auth_tok_for_sig(struct key **auth_tok_key,
666 struct ecryptfs_auth_tok **auth_tok,
667 char *sig);
668int ecryptfs_write_lower(struct inode *ecryptfs_inode, char *data,
669 loff_t offset, size_t size);
670int ecryptfs_write_lower_page_segment(struct inode *ecryptfs_inode,
671 struct page *page_for_lower,
672 size_t offset_in_page, size_t size);
673int ecryptfs_write(struct inode *inode, char *data, loff_t offset, size_t size);
674int ecryptfs_read_lower(char *data, loff_t offset, size_t size,
675 struct inode *ecryptfs_inode);
676int ecryptfs_read_lower_page_segment(struct page *page_for_ecryptfs,
677 pgoff_t page_index,
678 size_t offset_in_page, size_t size,
679 struct inode *ecryptfs_inode);
680struct page *ecryptfs_get_locked_page(struct inode *inode, loff_t index);
681int ecryptfs_parse_packet_length(unsigned char *data, size_t *size,
682 size_t *length_size);
683int ecryptfs_write_packet_length(char *dest, size_t size,
684 size_t *packet_size_length);
685#ifdef CONFIG_ECRYPT_FS_MESSAGING
686int ecryptfs_init_ecryptfs_miscdev(void);
687void ecryptfs_destroy_ecryptfs_miscdev(void);
688int ecryptfs_send_miscdev(char *data, size_t data_size,
689 struct ecryptfs_msg_ctx *msg_ctx, u8 msg_type,
690 u16 msg_flags, struct ecryptfs_daemon *daemon);
691void ecryptfs_msg_ctx_alloc_to_free(struct ecryptfs_msg_ctx *msg_ctx);
692int
693ecryptfs_spawn_daemon(struct ecryptfs_daemon **daemon, struct file *file);
694int ecryptfs_exorcise_daemon(struct ecryptfs_daemon *daemon);
695int ecryptfs_find_daemon_by_euid(struct ecryptfs_daemon **daemon);
696#endif
697int ecryptfs_init_kthread(void);
698void ecryptfs_destroy_kthread(void);
699int ecryptfs_privileged_open(struct file **lower_file,
700 struct dentry *lower_dentry,
701 struct vfsmount *lower_mnt,
702 const struct cred *cred);
703int ecryptfs_get_lower_file(struct dentry *dentry, struct inode *inode);
704void ecryptfs_put_lower_file(struct inode *inode);
705int
706ecryptfs_write_tag_70_packet(char *dest, size_t *remaining_bytes,
707 size_t *packet_size,
708 struct ecryptfs_mount_crypt_stat *mount_crypt_stat,
709 char *filename, size_t filename_size);
710int
711ecryptfs_parse_tag_70_packet(char **filename, size_t *filename_size,
712 size_t *packet_size,
713 struct ecryptfs_mount_crypt_stat *mount_crypt_stat,
714 char *data, size_t max_packet_size);
715int ecryptfs_set_f_namelen(long *namelen, long lower_namelen,
716 struct ecryptfs_mount_crypt_stat *mount_crypt_stat);
717int ecryptfs_derive_iv(char *iv, struct ecryptfs_crypt_stat *crypt_stat,
718 loff_t offset);
719
720extern const struct xattr_handler *ecryptfs_xattr_handlers[];
721
722#endif /* #ifndef ECRYPTFS_KERNEL_H */