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|
/**
* eCryptfs: Linux filesystem encryption layer
* Kernel declarations.
*
* Copyright (C) 1997-2003 Erez Zadok
* Copyright (C) 2001-2003 Stony Brook University
* Copyright (C) 2004-2008 International Business Machines Corp.
* Author(s): Michael A. Halcrow <mahalcro@us.ibm.com>
* Trevor S. Highland <trevor.highland@gmail.com>
* Tyler Hicks <tyhicks@ou.edu>
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License as
* published by the Free Software Foundation; either version 2 of the
* License, or (at your option) any later version.
*
* This program is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA
* 02111-1307, USA.
*/
#ifndef ECRYPTFS_KERNEL_H
#define ECRYPTFS_KERNEL_H
#include <crypto/skcipher.h>
#include <keys/user-type.h>
#include <keys/encrypted-type.h>
#include <linux/fs.h>
#include <linux/fs_stack.h>
#include <linux/namei.h>
#include <linux/scatterlist.h>
#include <linux/hash.h>
#include <linux/nsproxy.h>
#include <linux/backing-dev.h>
#include <linux/ecryptfs.h>
#define ECRYPTFS_DEFAULT_IV_BYTES 16
#define ECRYPTFS_DEFAULT_EXTENT_SIZE 4096
#define ECRYPTFS_MINIMUM_HEADER_EXTENT_SIZE 8192
#define ECRYPTFS_DEFAULT_MSG_CTX_ELEMS 32
#define ECRYPTFS_DEFAULT_SEND_TIMEOUT HZ
#define ECRYPTFS_MAX_MSG_CTX_TTL (HZ*3)
#define ECRYPTFS_DEFAULT_NUM_USERS 4
#define ECRYPTFS_MAX_NUM_USERS 32768
#define ECRYPTFS_XATTR_NAME "user.ecryptfs"
void ecryptfs_dump_auth_tok(struct ecryptfs_auth_tok *auth_tok);
extern void ecryptfs_to_hex(char *dst, char *src, size_t src_size);
extern void ecryptfs_from_hex(char *dst, char *src, int dst_size);
struct ecryptfs_key_record {
unsigned char type;
size_t enc_key_size;
unsigned char sig[ECRYPTFS_SIG_SIZE];
unsigned char enc_key[ECRYPTFS_MAX_ENCRYPTED_KEY_BYTES];
};
struct ecryptfs_auth_tok_list {
struct ecryptfs_auth_tok *auth_tok;
struct list_head list;
};
struct ecryptfs_crypt_stat;
struct ecryptfs_mount_crypt_stat;
struct ecryptfs_page_crypt_context {
struct page *page;
#define ECRYPTFS_PREPARE_COMMIT_MODE 0
#define ECRYPTFS_WRITEPAGE_MODE 1
unsigned int mode;
union {
struct file *lower_file;
struct writeback_control *wbc;
} param;
};
#if defined(CONFIG_ENCRYPTED_KEYS) || defined(CONFIG_ENCRYPTED_KEYS_MODULE)
static inline struct ecryptfs_auth_tok *
ecryptfs_get_encrypted_key_payload_data(struct key *key)
{
if (key->type == &key_type_encrypted)
return (struct ecryptfs_auth_tok *)
(&((struct encrypted_key_payload *)key->payload.data[0])->payload_data);
else
return NULL;
}
static inline struct key *ecryptfs_get_encrypted_key(char *sig)
{
return request_key(&key_type_encrypted, sig, NULL);
}
#else
static inline struct ecryptfs_auth_tok *
ecryptfs_get_encrypted_key_payload_data(struct key *key)
{
return NULL;
}
static inline struct key *ecryptfs_get_encrypted_key(char *sig)
{
return ERR_PTR(-ENOKEY);
}
#endif /* CONFIG_ENCRYPTED_KEYS */
static inline struct ecryptfs_auth_tok *
ecryptfs_get_key_payload_data(struct key *key)
{
struct ecryptfs_auth_tok *auth_tok;
auth_tok = ecryptfs_get_encrypted_key_payload_data(key);
if (!auth_tok)
return (struct ecryptfs_auth_tok *)user_key_payload_locked(key)->data;
else
return auth_tok;
}
#define ECRYPTFS_MAX_KEYSET_SIZE 1024
#define ECRYPTFS_MAX_CIPHER_NAME_SIZE 31
#define ECRYPTFS_MAX_NUM_ENC_KEYS 64
#define ECRYPTFS_MAX_IV_BYTES 16 /* 128 bits */
#define ECRYPTFS_SALT_BYTES 2
#define MAGIC_ECRYPTFS_MARKER 0x3c81b7f5
#define MAGIC_ECRYPTFS_MARKER_SIZE_BYTES 8 /* 4*2 */
#define ECRYPTFS_FILE_SIZE_BYTES (sizeof(u64))
#define ECRYPTFS_SIZE_AND_MARKER_BYTES (ECRYPTFS_FILE_SIZE_BYTES \
+ MAGIC_ECRYPTFS_MARKER_SIZE_BYTES)
#define ECRYPTFS_DEFAULT_CIPHER "aes"
#define ECRYPTFS_DEFAULT_KEY_BYTES 16
#define ECRYPTFS_DEFAULT_HASH "md5"
#define ECRYPTFS_TAG_70_DIGEST ECRYPTFS_DEFAULT_HASH
#define ECRYPTFS_TAG_1_PACKET_TYPE 0x01
#define ECRYPTFS_TAG_3_PACKET_TYPE 0x8C
#define ECRYPTFS_TAG_11_PACKET_TYPE 0xED
#define ECRYPTFS_TAG_64_PACKET_TYPE 0x40
#define ECRYPTFS_TAG_65_PACKET_TYPE 0x41
#define ECRYPTFS_TAG_66_PACKET_TYPE 0x42
#define ECRYPTFS_TAG_67_PACKET_TYPE 0x43
#define ECRYPTFS_TAG_70_PACKET_TYPE 0x46 /* FNEK-encrypted filename
* as dentry name */
#define ECRYPTFS_TAG_71_PACKET_TYPE 0x47 /* FNEK-encrypted filename in
* metadata */
#define ECRYPTFS_TAG_72_PACKET_TYPE 0x48 /* FEK-encrypted filename as
* dentry name */
#define ECRYPTFS_TAG_73_PACKET_TYPE 0x49 /* FEK-encrypted filename as
* metadata */
#define ECRYPTFS_MIN_PKT_LEN_SIZE 1 /* Min size to specify packet length */
#define ECRYPTFS_MAX_PKT_LEN_SIZE 2 /* Pass at least this many bytes to
* ecryptfs_parse_packet_length() and
* ecryptfs_write_packet_length()
*/
/* Constraint: ECRYPTFS_FILENAME_MIN_RANDOM_PREPEND_BYTES >=
* ECRYPTFS_MAX_IV_BYTES */
#define ECRYPTFS_FILENAME_MIN_RANDOM_PREPEND_BYTES 16
#define ECRYPTFS_NON_NULL 0x42 /* A reasonable substitute for NULL */
#define MD5_DIGEST_SIZE 16
#define ECRYPTFS_TAG_70_DIGEST_SIZE MD5_DIGEST_SIZE
#define ECRYPTFS_TAG_70_MIN_METADATA_SIZE (1 + ECRYPTFS_MIN_PKT_LEN_SIZE \
+ ECRYPTFS_SIG_SIZE + 1 + 1)
#define ECRYPTFS_TAG_70_MAX_METADATA_SIZE (1 + ECRYPTFS_MAX_PKT_LEN_SIZE \
+ ECRYPTFS_SIG_SIZE + 1 + 1)
#define ECRYPTFS_FEK_ENCRYPTED_FILENAME_PREFIX "ECRYPTFS_FEK_ENCRYPTED."
#define ECRYPTFS_FEK_ENCRYPTED_FILENAME_PREFIX_SIZE 23
#define ECRYPTFS_FNEK_ENCRYPTED_FILENAME_PREFIX "ECRYPTFS_FNEK_ENCRYPTED."
#define ECRYPTFS_FNEK_ENCRYPTED_FILENAME_PREFIX_SIZE 24
#define ECRYPTFS_ENCRYPTED_DENTRY_NAME_LEN (18 + 1 + 4 + 1 + 32)
#ifdef CONFIG_ECRYPT_FS_MESSAGING
# define ECRYPTFS_VERSIONING_MASK_MESSAGING (ECRYPTFS_VERSIONING_DEVMISC \
| ECRYPTFS_VERSIONING_PUBKEY)
#else
# define ECRYPTFS_VERSIONING_MASK_MESSAGING 0
#endif
#define ECRYPTFS_VERSIONING_MASK (ECRYPTFS_VERSIONING_PASSPHRASE \
| ECRYPTFS_VERSIONING_PLAINTEXT_PASSTHROUGH \
| ECRYPTFS_VERSIONING_XATTR \
| ECRYPTFS_VERSIONING_MULTKEY \
| ECRYPTFS_VERSIONING_MASK_MESSAGING \
| ECRYPTFS_VERSIONING_FILENAME_ENCRYPTION)
struct ecryptfs_key_sig {
struct list_head crypt_stat_list;
char keysig[ECRYPTFS_SIG_SIZE_HEX + 1];
};
struct ecryptfs_filename {
struct list_head crypt_stat_list;
#define ECRYPTFS_FILENAME_CONTAINS_DECRYPTED 0x00000001
u32 flags;
u32 seq_no;
char *filename;
char *encrypted_filename;
size_t filename_size;
size_t encrypted_filename_size;
char fnek_sig[ECRYPTFS_SIG_SIZE_HEX];
char dentry_name[ECRYPTFS_ENCRYPTED_DENTRY_NAME_LEN + 1];
};
/**
* This is the primary struct associated with each encrypted file.
*
* TODO: cache align/pack?
*/
struct ecryptfs_crypt_stat {
#define ECRYPTFS_STRUCT_INITIALIZED 0x00000001
#define ECRYPTFS_POLICY_APPLIED 0x00000002
#define ECRYPTFS_ENCRYPTED 0x00000004
#define ECRYPTFS_SECURITY_WARNING 0x00000008
#define ECRYPTFS_ENABLE_HMAC 0x00000010
#define ECRYPTFS_ENCRYPT_IV_PAGES 0x00000020
#define ECRYPTFS_KEY_VALID 0x00000040
#define ECRYPTFS_METADATA_IN_XATTR 0x00000080
#define ECRYPTFS_VIEW_AS_ENCRYPTED 0x00000100
#define ECRYPTFS_KEY_SET 0x00000200
#define ECRYPTFS_ENCRYPT_FILENAMES 0x00000400
#define ECRYPTFS_ENCFN_USE_MOUNT_FNEK 0x00000800
#define ECRYPTFS_ENCFN_USE_FEK 0x00001000
#define ECRYPTFS_UNLINK_SIGS 0x00002000
#define ECRYPTFS_I_SIZE_INITIALIZED 0x00004000
u32 flags;
unsigned int file_version;
size_t iv_bytes;
size_t metadata_size;
size_t extent_size; /* Data extent size; default is 4096 */
size_t key_size;
size_t extent_shift;
unsigned int extent_mask;
struct ecryptfs_mount_crypt_stat *mount_crypt_stat;
struct crypto_skcipher *tfm;
struct crypto_shash *hash_tfm; /* Crypto context for generating
* the initialization vectors */
unsigned char cipher[ECRYPTFS_MAX_CIPHER_NAME_SIZE + 1];
unsigned char key[ECRYPTFS_MAX_KEY_BYTES];
unsigned char root_iv[ECRYPTFS_MAX_IV_BYTES];
struct list_head keysig_list;
struct mutex keysig_list_mutex;
struct mutex cs_tfm_mutex;
struct mutex cs_mutex;
};
/* inode private data. */
struct ecryptfs_inode_info {
struct inode vfs_inode;
struct inode *wii_inode;
struct mutex lower_file_mutex;
atomic_t lower_file_count;
struct file *lower_file;
struct ecryptfs_crypt_stat crypt_stat;
};
/* dentry private data. Each dentry must keep track of a lower
* vfsmount too. */
struct ecryptfs_dentry_info {
struct path lower_path;
union {
struct ecryptfs_crypt_stat *crypt_stat;
struct rcu_head rcu;
};
};
/**
* ecryptfs_global_auth_tok - A key used to encrypt all new files under the mountpoint
* @flags: Status flags
* @mount_crypt_stat_list: These auth_toks hang off the mount-wide
* cryptographic context. Every time a new
* inode comes into existence, eCryptfs copies
* the auth_toks on that list to the set of
* auth_toks on the inode's crypt_stat
* @global_auth_tok_key: The key from the user's keyring for the sig
* @global_auth_tok: The key contents
* @sig: The key identifier
*
* ecryptfs_global_auth_tok structs refer to authentication token keys
* in the user keyring that apply to newly created files. A list of
* these objects hangs off of the mount_crypt_stat struct for any
* given eCryptfs mount. This struct maintains a reference to both the
* key contents and the key itself so that the key can be put on
* unmount.
*/
struct ecryptfs_global_auth_tok {
#define ECRYPTFS_AUTH_TOK_INVALID 0x00000001
#define ECRYPTFS_AUTH_TOK_FNEK 0x00000002
u32 flags;
struct list_head mount_crypt_stat_list;
struct key *global_auth_tok_key;
unsigned char sig[ECRYPTFS_SIG_SIZE_HEX + 1];
};
/**
* ecryptfs_key_tfm - Persistent key tfm
* @key_tfm: crypto API handle to the key
* @key_size: Key size in bytes
* @key_tfm_mutex: Mutex to ensure only one operation in eCryptfs is
* using the persistent TFM at any point in time
* @key_tfm_list: Handle to hang this off the module-wide TFM list
* @cipher_name: String name for the cipher for this TFM
*
* Typically, eC
|