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v5.9
  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 */
v6.13.7
  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	struct rcu_head rcu;
 
 
 
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};
353
354/* file private data. */
355struct ecryptfs_file_info {
356	struct file *wfi_file;
357	struct ecryptfs_crypt_stat *crypt_stat;
358};
359
360/* auth_tok <=> encrypted_session_key mappings */
361struct ecryptfs_auth_tok_list_item {
362	unsigned char encrypted_session_key[ECRYPTFS_MAX_KEY_BYTES];
363	struct list_head list;
364	struct ecryptfs_auth_tok auth_tok;
365};
366
367struct ecryptfs_message {
368	/* Can never be greater than ecryptfs_message_buf_len */
369	/* Used to find the parent msg_ctx */
370	/* Inherits from msg_ctx->index */
371	u32 index;
372	u32 data_len;
373	u8 data[];
374};
375
376struct ecryptfs_msg_ctx {
377#define ECRYPTFS_MSG_CTX_STATE_FREE     0x01
378#define ECRYPTFS_MSG_CTX_STATE_PENDING  0x02
379#define ECRYPTFS_MSG_CTX_STATE_DONE     0x03
380#define ECRYPTFS_MSG_CTX_STATE_NO_REPLY 0x04
381	u8 state;
382#define ECRYPTFS_MSG_HELO 100
383#define ECRYPTFS_MSG_QUIT 101
384#define ECRYPTFS_MSG_REQUEST 102
385#define ECRYPTFS_MSG_RESPONSE 103
386	u8 type;
387	u32 index;
388	/* Counter converts to a sequence number. Each message sent
389	 * out for which we expect a response has an associated
390	 * sequence number. The response must have the same sequence
391	 * number as the counter for the msg_stc for the message to be
392	 * valid. */
393	u32 counter;
394	size_t msg_size;
395	struct ecryptfs_message *msg;
396	struct task_struct *task;
397	struct list_head node;
398	struct list_head daemon_out_list;
399	struct mutex mux;
400};
401
402struct ecryptfs_daemon {
403#define ECRYPTFS_DAEMON_IN_READ      0x00000001
404#define ECRYPTFS_DAEMON_IN_POLL      0x00000002
405#define ECRYPTFS_DAEMON_ZOMBIE       0x00000004
406#define ECRYPTFS_DAEMON_MISCDEV_OPEN 0x00000008
407	u32 flags;
408	u32 num_queued_msg_ctx;
409	struct file *file;
410	struct mutex mux;
411	struct list_head msg_ctx_out_queue;
412	wait_queue_head_t wait;
413	struct hlist_node euid_chain;
414};
415
416#ifdef CONFIG_ECRYPT_FS_MESSAGING
417extern struct mutex ecryptfs_daemon_hash_mux;
418#endif
419
420static inline size_t
421ecryptfs_lower_header_size(struct ecryptfs_crypt_stat *crypt_stat)
422{
423	if (crypt_stat->flags & ECRYPTFS_METADATA_IN_XATTR)
424		return 0;
425	return crypt_stat->metadata_size;
426}
427
428static inline struct ecryptfs_file_info *
429ecryptfs_file_to_private(struct file *file)
430{
431	return file->private_data;
432}
433
434static inline void
435ecryptfs_set_file_private(struct file *file,
436			  struct ecryptfs_file_info *file_info)
437{
438	file->private_data = file_info;
439}
440
441static inline struct file *ecryptfs_file_to_lower(struct file *file)
442{
443	return ((struct ecryptfs_file_info *)file->private_data)->wfi_file;
444}
445
446static inline void
447ecryptfs_set_file_lower(struct file *file, struct file *lower_file)
448{
449	((struct ecryptfs_file_info *)file->private_data)->wfi_file =
450		lower_file;
451}
452
453static inline struct ecryptfs_inode_info *
454ecryptfs_inode_to_private(struct inode *inode)
455{
456	return container_of(inode, struct ecryptfs_inode_info, vfs_inode);
457}
458
459static inline struct inode *ecryptfs_inode_to_lower(struct inode *inode)
460{
461	return ecryptfs_inode_to_private(inode)->wii_inode;
462}
463
464static inline void
465ecryptfs_set_inode_lower(struct inode *inode, struct inode *lower_inode)
466{
467	ecryptfs_inode_to_private(inode)->wii_inode = lower_inode;
468}
469
470static inline struct ecryptfs_sb_info *
471ecryptfs_superblock_to_private(struct super_block *sb)
472{
473	return (struct ecryptfs_sb_info *)sb->s_fs_info;
474}
475
476static inline void
477ecryptfs_set_superblock_private(struct super_block *sb,
478				struct ecryptfs_sb_info *sb_info)
479{
480	sb->s_fs_info = sb_info;
481}
482
483static inline struct super_block *
484ecryptfs_superblock_to_lower(struct super_block *sb)
485{
486	return ((struct ecryptfs_sb_info *)sb->s_fs_info)->wsi_sb;
487}
488
489static inline void
490ecryptfs_set_superblock_lower(struct super_block *sb,
491			      struct super_block *lower_sb)
492{
493	((struct ecryptfs_sb_info *)sb->s_fs_info)->wsi_sb = lower_sb;
494}
495
 
 
 
 
 
 
496static inline void
497ecryptfs_set_dentry_private(struct dentry *dentry,
498			    struct ecryptfs_dentry_info *dentry_info)
499{
500	dentry->d_fsdata = dentry_info;
501}
502
503static inline struct dentry *
504ecryptfs_dentry_to_lower(struct dentry *dentry)
505{
506	return ((struct ecryptfs_dentry_info *)dentry->d_fsdata)->lower_path.dentry;
507}
508
509static inline const struct path *
 
 
 
 
 
 
510ecryptfs_dentry_to_lower_path(struct dentry *dentry)
511{
512	return &((struct ecryptfs_dentry_info *)dentry->d_fsdata)->lower_path;
513}
514
515#define ecryptfs_printk(type, fmt, arg...) \
516        __ecryptfs_printk(type "%s: " fmt, __func__, ## arg)
517__printf(1, 2)
518void __ecryptfs_printk(const char *fmt, ...);
519
520extern const struct file_operations ecryptfs_main_fops;
521extern const struct file_operations ecryptfs_dir_fops;
522extern const struct inode_operations ecryptfs_main_iops;
523extern const struct inode_operations ecryptfs_dir_iops;
524extern const struct inode_operations ecryptfs_symlink_iops;
525extern const struct super_operations ecryptfs_sops;
526extern const struct dentry_operations ecryptfs_dops;
527extern const struct address_space_operations ecryptfs_aops;
528extern int ecryptfs_verbosity;
529extern unsigned int ecryptfs_message_buf_len;
530extern signed long ecryptfs_message_wait_timeout;
531extern unsigned int ecryptfs_number_of_users;
532
533extern struct kmem_cache *ecryptfs_auth_tok_list_item_cache;
534extern struct kmem_cache *ecryptfs_file_info_cache;
535extern struct kmem_cache *ecryptfs_dentry_info_cache;
536extern struct kmem_cache *ecryptfs_inode_info_cache;
537extern struct kmem_cache *ecryptfs_sb_info_cache;
538extern struct kmem_cache *ecryptfs_header_cache;
539extern struct kmem_cache *ecryptfs_xattr_cache;
540extern struct kmem_cache *ecryptfs_key_record_cache;
541extern struct kmem_cache *ecryptfs_key_sig_cache;
542extern struct kmem_cache *ecryptfs_global_auth_tok_cache;
543extern struct kmem_cache *ecryptfs_key_tfm_cache;
544
545struct inode *ecryptfs_get_inode(struct inode *lower_inode,
546				 struct super_block *sb);
547void ecryptfs_i_size_init(const char *page_virt, struct inode *inode);
548int ecryptfs_initialize_file(struct dentry *ecryptfs_dentry,
549			     struct inode *ecryptfs_inode);
550int ecryptfs_decode_and_decrypt_filename(char **decrypted_name,
551					 size_t *decrypted_name_size,
552					 struct super_block *sb,
553					 const char *name, size_t name_size);
554int ecryptfs_fill_zeros(struct file *file, loff_t new_length);
555int ecryptfs_encrypt_and_encode_filename(
556	char **encoded_name,
557	size_t *encoded_name_size,
558	struct ecryptfs_mount_crypt_stat *mount_crypt_stat,
559	const char *name, size_t name_size);
560struct dentry *ecryptfs_lower_dentry(struct dentry *this_dentry);
561void ecryptfs_dump_hex(char *data, int bytes);
562int virt_to_scatterlist(const void *addr, int size, struct scatterlist *sg,
563			int sg_size);
564int ecryptfs_compute_root_iv(struct ecryptfs_crypt_stat *crypt_stat);
565void ecryptfs_rotate_iv(unsigned char *iv);
566int ecryptfs_init_crypt_stat(struct ecryptfs_crypt_stat *crypt_stat);
567void ecryptfs_destroy_crypt_stat(struct ecryptfs_crypt_stat *crypt_stat);
568void ecryptfs_destroy_mount_crypt_stat(
569	struct ecryptfs_mount_crypt_stat *mount_crypt_stat);
570int ecryptfs_init_crypt_ctx(struct ecryptfs_crypt_stat *crypt_stat);
571int ecryptfs_write_inode_size_to_metadata(struct inode *ecryptfs_inode);
572int ecryptfs_encrypt_page(struct folio *folio);
573int ecryptfs_decrypt_page(struct folio *folio);
574int ecryptfs_write_metadata(struct dentry *ecryptfs_dentry,
575			    struct inode *ecryptfs_inode);
576int ecryptfs_read_metadata(struct dentry *ecryptfs_dentry);
577int ecryptfs_new_file_context(struct inode *ecryptfs_inode);
578void ecryptfs_write_crypt_stat_flags(char *page_virt,
579				     struct ecryptfs_crypt_stat *crypt_stat,
580				     size_t *written);
581int ecryptfs_read_and_validate_header_region(struct inode *inode);
582int ecryptfs_read_and_validate_xattr_region(struct dentry *dentry,
583					    struct inode *inode);
584u8 ecryptfs_code_for_cipher_string(char *cipher_name, size_t key_bytes);
585int ecryptfs_cipher_code_to_string(char *str, u8 cipher_code);
586void ecryptfs_set_default_sizes(struct ecryptfs_crypt_stat *crypt_stat);
587int ecryptfs_generate_key_packet_set(char *dest_base,
588				     struct ecryptfs_crypt_stat *crypt_stat,
589				     struct dentry *ecryptfs_dentry,
590				     size_t *len, size_t max);
591int
592ecryptfs_parse_packet_set(struct ecryptfs_crypt_stat *crypt_stat,
593			  unsigned char *src, struct dentry *ecryptfs_dentry);
594int ecryptfs_truncate(struct dentry *dentry, loff_t new_length);
595ssize_t
596ecryptfs_getxattr_lower(struct dentry *lower_dentry, struct inode *lower_inode,
597			const char *name, void *value, size_t size);
598int
599ecryptfs_setxattr(struct dentry *dentry, struct inode *inode, const char *name,
600		  const void *value, size_t size, int flags);
601int ecryptfs_read_xattr_region(char *page_virt, struct inode *ecryptfs_inode);
602#ifdef CONFIG_ECRYPT_FS_MESSAGING
603int ecryptfs_process_response(struct ecryptfs_daemon *daemon,
604			      struct ecryptfs_message *msg, u32 seq);
605int ecryptfs_send_message(char *data, int data_len,
606			  struct ecryptfs_msg_ctx **msg_ctx);
607int ecryptfs_wait_for_response(struct ecryptfs_msg_ctx *msg_ctx,
608			       struct ecryptfs_message **emsg);
609int ecryptfs_init_messaging(void);
610void ecryptfs_release_messaging(void);
611#else
612static inline int ecryptfs_init_messaging(void)
613{
614	return 0;
615}
616static inline void ecryptfs_release_messaging(void)
617{ }
618static inline int ecryptfs_send_message(char *data, int data_len,
619					struct ecryptfs_msg_ctx **msg_ctx)
620{
621	return -ENOTCONN;
622}
623static inline int ecryptfs_wait_for_response(struct ecryptfs_msg_ctx *msg_ctx,
624					     struct ecryptfs_message **emsg)
625{
626	return -ENOMSG;
627}
628#endif
629
630void
631ecryptfs_write_header_metadata(char *virt,
632			       struct ecryptfs_crypt_stat *crypt_stat,
633			       size_t *written);
634int ecryptfs_add_keysig(struct ecryptfs_crypt_stat *crypt_stat, char *sig);
635int
636ecryptfs_add_global_auth_tok(struct ecryptfs_mount_crypt_stat *mount_crypt_stat,
637			   char *sig, u32 global_auth_tok_flags);
638int ecryptfs_get_global_auth_tok_for_sig(
639	struct ecryptfs_global_auth_tok **global_auth_tok,
640	struct ecryptfs_mount_crypt_stat *mount_crypt_stat, char *sig);
641int
642ecryptfs_add_new_key_tfm(struct ecryptfs_key_tfm **key_tfm, char *cipher_name,
643			 size_t key_size);
644int ecryptfs_init_crypto(void);
645int ecryptfs_destroy_crypto(void);
646int ecryptfs_tfm_exists(char *cipher_name, struct ecryptfs_key_tfm **key_tfm);
647int ecryptfs_get_tfm_and_mutex_for_cipher_name(struct crypto_skcipher **tfm,
648					       struct mutex **tfm_mutex,
649					       char *cipher_name);
650int ecryptfs_keyring_auth_tok_for_sig(struct key **auth_tok_key,
651				      struct ecryptfs_auth_tok **auth_tok,
652				      char *sig);
653int ecryptfs_write_lower(struct inode *ecryptfs_inode, char *data,
654			 loff_t offset, size_t size);
655int ecryptfs_write_lower_page_segment(struct inode *ecryptfs_inode,
656				      struct folio *folio_for_lower,
657				      size_t offset_in_page, size_t size);
658int ecryptfs_write(struct inode *inode, char *data, loff_t offset, size_t size);
659int ecryptfs_read_lower(char *data, loff_t offset, size_t size,
660			struct inode *ecryptfs_inode);
661int ecryptfs_read_lower_page_segment(struct folio *folio_for_ecryptfs,
662				     pgoff_t page_index,
663				     size_t offset_in_page, size_t size,
664				     struct inode *ecryptfs_inode);
 
665int ecryptfs_parse_packet_length(unsigned char *data, size_t *size,
666				 size_t *length_size);
667int ecryptfs_write_packet_length(char *dest, size_t size,
668				 size_t *packet_size_length);
669#ifdef CONFIG_ECRYPT_FS_MESSAGING
670int ecryptfs_init_ecryptfs_miscdev(void);
671void ecryptfs_destroy_ecryptfs_miscdev(void);
672int ecryptfs_send_miscdev(char *data, size_t data_size,
673			  struct ecryptfs_msg_ctx *msg_ctx, u8 msg_type,
674			  u16 msg_flags, struct ecryptfs_daemon *daemon);
675void ecryptfs_msg_ctx_alloc_to_free(struct ecryptfs_msg_ctx *msg_ctx);
676int
677ecryptfs_spawn_daemon(struct ecryptfs_daemon **daemon, struct file *file);
678int ecryptfs_exorcise_daemon(struct ecryptfs_daemon *daemon);
679int ecryptfs_find_daemon_by_euid(struct ecryptfs_daemon **daemon);
680#endif
681int ecryptfs_init_kthread(void);
682void ecryptfs_destroy_kthread(void);
683int ecryptfs_privileged_open(struct file **lower_file,
684			     struct dentry *lower_dentry,
685			     struct vfsmount *lower_mnt,
686			     const struct cred *cred);
687int ecryptfs_get_lower_file(struct dentry *dentry, struct inode *inode);
688void ecryptfs_put_lower_file(struct inode *inode);
689int
690ecryptfs_write_tag_70_packet(char *dest, size_t *remaining_bytes,
691			     size_t *packet_size,
692			     struct ecryptfs_mount_crypt_stat *mount_crypt_stat,
693			     char *filename, size_t filename_size);
694int
695ecryptfs_parse_tag_70_packet(char **filename, size_t *filename_size,
696			     size_t *packet_size,
697			     struct ecryptfs_mount_crypt_stat *mount_crypt_stat,
698			     char *data, size_t max_packet_size);
699int ecryptfs_set_f_namelen(long *namelen, long lower_namelen,
700			   struct ecryptfs_mount_crypt_stat *mount_crypt_stat);
701int ecryptfs_derive_iv(char *iv, struct ecryptfs_crypt_stat *crypt_stat,
702		       loff_t offset);
703
704extern const struct xattr_handler * const ecryptfs_xattr_handlers[];
705
706#endif /* #ifndef ECRYPTFS_KERNEL_H */