/**
* eCryptfs: Linux filesystem encryption layer
* Kernel declarations.
*
* Copyright (C) 1997-2003 Erez Zadok
* Copyright (C) 2001-2003 Stony Brook University
* Copyright (C) 2004-2006 International Business Machines Corp.
* Author(s): Michael A. Halcrow <mahalcro@us.ibm.com>
*
* 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 <keys/user-type.h>
#include <linux/fs.h>
#include <linux/fs_stack.h>
#include <linux/namei.h>
#include <linux/scatterlist.h>
/* Version verification for shared data structures w/ userspace */
#define ECRYPTFS_VERSION_MAJOR 0x00
#define ECRYPTFS_VERSION_MINOR 0x04
#define ECRYPTFS_SUPPORTED_FILE_VERSION 0x01
/* These flags indicate which features are supported by the kernel
* module; userspace tools such as the mount helper read
* ECRYPTFS_VERSIONING_MASK from a sysfs handle in order to determine
* how to behave. */
#define ECRYPTFS_VERSIONING_PASSPHRASE 0x00000001
#define ECRYPTFS_VERSIONING_PUBKEY 0x00000002
#define ECRYPTFS_VERSIONING_PLAINTEXT_PASSTHROUGH 0x00000004
#define ECRYPTFS_VERSIONING_POLICY 0x00000008
#define ECRYPTFS_VERSIONING_MASK (ECRYPTFS_VERSIONING_PASSPHRASE \
| ECRYPTFS_VERSIONING_PLAINTEXT_PASSTHROUGH)
#define ECRYPTFS_MAX_PASSWORD_LENGTH 64
#define ECRYPTFS_MAX_PASSPHRASE_BYTES ECRYPTFS_MAX_PASSWORD_LENGTH
#define ECRYPTFS_SALT_SIZE 8
#define ECRYPTFS_SALT_SIZE_HEX (ECRYPTFS_SALT_SIZE*2)
/* The original signature size is only for what is stored on disk; all
* in-memory representations are expanded hex, so it better adapted to
* be passed around or referenced on the command line */
#define ECRYPTFS_SIG_SIZE 8
#define ECRYPTFS_SIG_SIZE_HEX (ECRYPTFS_SIG_SIZE*2)
#define ECRYPTFS_PASSWORD_SIG_SIZE ECRYPTFS_SIG_SIZE_HEX
#define ECRYPTFS_MAX_KEY_BYTES 64
#define ECRYPTFS_MAX_ENCRYPTED_KEY_BYTES 512
#define ECRYPTFS_DEFAULT_IV_BYTES 16
#define ECRYPTFS_FILE_VERSION 0x01
#define ECRYPTFS_DEFAULT_HEADER_EXTENT_SIZE 8192
#define ECRYPTFS_DEFAULT_EXTENT_SIZE 4096
#define ECRYPTFS_MINIMUM_HEADER_EXTENT_SIZE 8192
#define RFC2440_CIPHER_DES3_EDE 0x02
#define RFC2440_CIPHER_CAST_5 0x03
#define RFC2440_CIPHER_BLOWFISH 0x04
#define RFC2440_CIPHER_AES_128 0x07
#define RFC2440_CIPHER_AES_192 0x08
#define RFC2440_CIPHER_AES_256 0x09
#define RFC2440_CIPHER_TWOFISH 0x0a
#define RFC2440_CIPHER_CAST_6 0x0b
#define ECRYPTFS_SET_FLAG(flag_bit_vector, flag) (flag_bit_vector |= (flag))
#define ECRYPTFS_CLEAR_FLAG(flag_bit_vector, flag) (flag_bit_vector &= ~(flag))
#define ECRYPTFS_CHECK_FLAG(flag_bit_vector, flag) (flag_bit_vector & (flag))
/**
* For convenience, we may need to pass around the encrypted session
* key between kernel and userspace because the authentication token
* may not be extractable. For example, the TPM may not release the
* private key, instead requiring the encrypted data and returning the
* decrypted data.
*/
struct ecryptfs_session_key {
#define ECRYPTFS_USERSPACE_SHOULD_TRY_TO_DECRYPT 0x00000001
#define ECRYPTFS_USERSPACE_SHOULD_TRY_TO_ENCRYPT 0x00000002
#define ECRYPTFS_CONTAINS_DECRYPTED_KEY 0x00000004
#define ECRYPTFS_CONTAINS_ENCRYPTED_KEY 0x00000008
u32 flags;
u32 encrypted_key_size;
u32 decrypted_key_size;
u8 encrypted_key[ECRYPTFS_MAX_ENCRYPTED_KEY_BYTES];
u8 decrypted_key[ECRYPTFS_MAX_KEY_BYTES];
};
struct ecryptfs_password {
u32 password_bytes;
s32 hash_algo;
u32 hash_iterations;
u32 session_key_encryption_key_bytes;
#define ECRYPTFS_PERSISTENT_PASSWORD 0x01
#define ECRYPTFS_SESSION_KEY_ENCRYPTION_KEY_SET 0x02
u32 flags;
/* Iterated-hash concatenation of salt and passphrase */
u8 session_key_encryption_key[ECRYPTFS_MAX_KEY_BYTES];
u8 signature[ECRYPTFS_PASSWORD_SIG_SIZE + 1];
/* Always in expanded hex */
u8 salt[ECRYPTFS_SALT_SIZE];
};
enum ecryptfs_token_types {ECRYPTFS_PASSWORD, ECRYPTFS_PRIVATE_KEY};
/* May be a password or a private key */
struct ecryptfs_auth_tok {
u16 version; /* 8-bit major and 8-bit minor */
u16 token_type;
u32 flags;
struct ecryptfs_session_key session_key;
u8 reserved[32];
union {
struct ecryptfs_password password;
/* Private key is in future eCryptfs releases */
} token;
} __attribute__ ((packed));
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;
};
static inline struct ecryptfs_auth_tok *
ecryptfs_get_key_payload_data(struct key *key)
{
return (struct ecryptfs_auth_tok *)
(((struct user_key_payload*)key->payload.data)->data);
}
#define ECRYPTFS_SUPER_MAGIC 0xf15f
#define ECRYPTFS_MAX_KEYSET_SIZE 1024
#define ECRYPTFS_MAX_CIPHER_NAME_SIZE 32
#define ECRYPTFS_MAX_NUM_ENC_KEYS 64
#define ECRYPTFS_MAX_NUM_KEYSIGS 2 /* TODO: Make this a linked list */
#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 8
#define ECRYPTFS_DEFAULT_CIPHER "aes"
#define ECRYPTFS_DEFAULT_KEY_BYTES 16
#define ECRYPTFS_DEFAULT_CHAINING_MODE CRYPTO_TFM_MODE_CBC
#define ECRYPTFS_DEFAULT_HASH "md5"
#define ECRYPTFS_TAG_3_PACKET_TYPE 0x8C
#define ECRYPTFS_TAG_11_PACKET_TYPE 0xED
#define MD5_DIGEST_SIZE 16
/**
* 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_NEW_FILE 0x00000004
#define ECRYPTFS_ENCRYPTED 0x00000008
#define ECRYPTFS_SECURITY_WARNING 0x00000010
#define ECRYPTFS_ENABLE_HMAC 0x00000020
#define ECRYPTFS_ENCRYPT_IV_PAGES 0x00000040
#define ECRYPTFS_KEY_VALID 0x00000080
u32 flags;
unsigned int file_version;
size_t iv_bytes;
size_t num_keysigs;
size_t header_extent_size;
size_t num_header_extents_at_front;
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_blkcipher *tfm;
struct crypto_hash *hash_tfm; /* Crypto context for generating
* the initialization vectors */
unsigned char cipher[ECRYPTFS_MAX_CIPHER_NAME_SIZE];
unsigned char key[ECRYPTFS_MAX_KEY_BYTES];
unsigned char root_iv[ECRYPTFS_MAX_IV_BYTES];
unsigned char keysigs[ECRYPTFS_MAX_NUM_KEYSIGS][ECRYPTFS_SIG_SIZE_HEX];
struct mutex cs_tfm_mutex;
struct mutex cs_hash_tfm_mutex;
struct mutex cs_mutex;
};
/* inode private data. */
struct ecryptfs_inode_info {
struct inode vfs_inode;
struct inode *wii_inode;
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;
struct ecryptfs_crypt_stat *crypt_stat;
};
/**
* This struct is to enable a mount-wide passphrase/salt combo. This
* is more or less a stopgap to provide similar functionality to other
* crypto filesystems like EncFS or CFS until full policy support is
* implemented in eCryptfs.
*/
struct ecryptfs_mount_crypt_stat {
/* Pointers to memory we do not own, do not free these */
#define ECRYPTFS_PLAINTEXT_PASSTHROUGH_ENABLED 0x00000001
u32 flags;
struct ecryptfs_auth_tok *global_auth_tok;
struct key *global_auth_tok_key;
size_t global_default_cipher_key_size;
struct crypto_blkcipher *global_key_tfm;
struct mutex global_key_tfm_mutex;
unsigned char global_default_cipher_name[ECRYPTFS_MAX_CIPHER_NAME_SIZE
+ 1];
unsigned char global_auth_tok_sig[ECRYPTFS_SIG_SIZE_HEX + 1];
};
/* superblock private data. */
struct ecryptfs_sb_info {
struct super_block *wsi_sb;
struct ecryptfs_mount_crypt_stat mount_crypt_stat;
};
/* file private data. */
struct ecryptfs_file_info {
struct file *wfi_file;
struct ecryptfs_crypt_stat *crypt_stat;
};
/* auth_tok <=> encrypted_session_key mappings */
struct ecryptfs_auth_tok_list_item {
unsigned char encrypted_session_key[ECRYPTFS_MAX_KEY_BYTES];
struct list_head list;
struct ecryptfs_auth_tok auth_tok;
};
static inline struct ecryptfs_file_info *
ecryptfs_file_to_private(struct file *file)
{
return (struct ecryptfs_file_info *)file->private_data;
}
static inline void
ecryptfs_set_file_private(struct file *file,
struct ecryptfs_file_info *file_info)
{
file->private_data = file_info;
}
static inline struct file *ecryptfs_file_to_lower(struct file *file)
{
return ((struct ecryptfs_file_info *)file->private_data)->wfi_file;
}
static inline void
ecryptfs_set_file_lower(struct file *file, struct file *lower_file)
{
((struct ecryptfs_file_info *)file->private_data)->wfi_file =
lower_file;
}
static inline struct ecryptfs_inode_info *
ecryptfs_inode_to_private(struct inode *inode)
{
return container_of(inode, struct ecryptfs_inode_info, vfs_inode);
}
static inline struct inode *ecryptfs_inode_to_lower(struct inode *inode)
{
return ecryptfs_inode_to_private(inode)->wii_inode;
}
static inline void
ecryptfs_set_inode_lower(struct inode *inode, struct inode *lower_inode)
{
ecryptfs_inode_to_private(inode)->wii_inode = lower_inode;
}
static inline struct ecryptfs_sb_info *
ecryptfs_superblock_to_private(struct super_block *sb)
{
return (struct ecryptfs_sb_info *)sb->s_fs_info;
}
static inline void
ecryptfs_set_superblock_private(struct super_block *sb,
struct ecryptfs_sb_info *sb_info)
{
sb->s_fs_info = sb_info;
}
static inline struct super_block *
ecryptfs_superblock_to_lower(struct super_block *sb)
{
return ((struct ecryptfs_sb_info *)sb->s_fs_info)->wsi_sb;
}
static inline void
ecryptfs_set_superblock_lower(struct super_block *sb,
struct super_block *lower_sb)
{
((struct ecryptfs_sb_info *)sb->s_fs_info)->wsi_sb = lower_sb;
}
static inline struct ecryptfs_dentry_info *
ecryptfs_dentry_to_private(struct dentry *dentry)
{
return (struct ecryptfs_dentry_info *)dentry->d_fsdata;
}
static inline void
ecryptfs_set_dentry_private(struct dentry *dentry,
struct ecryptfs_dentry_info *dentry_info)
{
dentry->d_fsdata = dentry_info;
}
static inline struct dentry *
ecryptfs_dentry_to_lower(struct dentry *dentry)
{
return ((struct ecryptfs_dentry_info *)dentry->d_fsdata)->lower_path.dentry;
}
static inline void
ecryptfs_set_dentry_lower(struct dentry *dentry, struct dentry *lower_dentry)
{
((struct ecryptfs_dentry_info *)dentry->d_fsdata)->lower_path.dentry =
lower_dentry;
}
static inline struct vfsmount *
ecryptfs_dentry_to_lower_mnt(struct dentry *dentry)
{
return ((struct ecryptfs_dentry_info *)dentry->d_fsdata)->lower_path.mnt;
}
static inline void
ecryptfs_set_dentry_lower_mnt(struct dentry *dentry, struct vfsmount *lower_mnt)
{
((struct ecryptfs_dentry_info *)dentry->d_fsdata)->lower_path.mnt =
lower_mnt;
}
#define ecryptfs_printk(type, fmt, arg...) \
__ecryptfs_printk(type "%s: " fmt, __FUNCTION__, ## arg);
void __ecryptfs_printk(const char *fmt, ...);
extern const struct file_operations ecryptfs_main_fops;
extern const struct file_operations ecryptfs_dir_fops;
extern struct inode_operations ecryptfs_main_iops;
extern struct inode_operations ecryptfs_dir_iops;
extern struct inode_operations ecryptfs_symlink_iops;
extern struct super_operations ecryptfs_sops;
extern struct dentry_operations ecryptfs_dops;
extern struct address_space_operations ecryptfs_aops;
extern int ecryptfs_verbosity;
extern struct kmem_cache *ecryptfs_auth_tok_list_item_cache;
extern struct kmem_cache *ecryptfs_file_info_cache;
extern struct kmem_cache *ecryptfs_dentry_info_cache;
extern struct kmem_cache *ecryptfs_inode_info_cache;
extern struct kmem_cache *ecryptfs_sb_info_cache;
extern struct kmem_cache *ecryptfs_header_cache_0;
extern struct kmem_cache *ecryptfs_header_cache_1;
extern struct kmem_cache *ecryptfs_header_cache_2;
extern struct kmem_cache *ecryptfs_lower_page_cache;
int ecryptfs_interpose(struct dentry *hidden_dentry,
struct dentry *this_dentry, struct super_block *sb,
int flag);
int ecryptfs_fill_zeros(struct file *file, loff_t new_length);
int ecryptfs_decode_filename(struct ecryptfs_crypt_stat *crypt_stat,
const char *name, int length,
char **decrypted_name);
int ecryptfs_encode_filename(struct ecryptfs_crypt_stat *crypt_stat,
const char *name, int length,
char **encoded_name);
struct dentry *ecryptfs_lower_dentry(struct dentry *this_dentry);
void ecryptfs_dump_hex(char *data, int bytes);
int virt_to_scatterlist(const void *addr, int size, struct scatterlist *sg,
int sg_size);
int ecryptfs_compute_root_iv(struct ecryptfs_crypt_stat *crypt_stat);
void ecryptfs_rotate_iv(unsigned char *iv);
void ecryptfs_init_crypt_stat(struct ecryptfs_crypt_stat *crypt_stat);
void ecryptfs_destruct_crypt_stat(struct ecryptfs_crypt_stat *crypt_stat);
void ecryptfs_destruct_mount_crypt_stat(
struct ecryptfs_mount_crypt_stat *mount_crypt_stat);
int ecryptfs_init_crypt_ctx(struct ecryptfs_crypt_stat *crypt_stat);
int ecryptfs_crypto_api_algify_cipher_name(char **algified_name,
char *cipher_name,
char *chaining_modifier);
int ecryptfs_write_inode_size_to_header(struct file *lower_file,
struct inode *lower_inode,
struct inode *inode);
int ecryptfs_get_lower_page(struct page **lower_page, struct inode *lower_inode,
struct file *lower_file,
unsigned long lower_page_index, int byte_offset,
int region_bytes);
int
ecryptfs_commit_lower_page(struct page *lower_page, struct inode *lower_inode,
struct file *lower_file, int byte_offset,
int region_size);
int ecryptfs_copy_page_to_lower(struct page *page, struct inode *lower_inode,
struct file *lower_file);
int ecryptfs_do_readpage(struct file *file, struct page *page,
pgoff_t lower_page_index);
int ecryptfs_grab_and_map_lower_page(struct page **lower_page,
char **lower_virt,
struct inode *lower_inode,
unsigned long lower_page_index);
int ecryptfs_writepage_and_release_lower_page(struct page *lower_page,
struct inode *lower_inode,
struct writeback_control *wbc);
int ecryptfs_encrypt_page(struct ecryptfs_page_crypt_context *ctx);
int ecryptfs_decrypt_page(struct file *file, struct page *page);
int ecryptfs_write_headers(struct dentry *ecryptfs_dentry,
struct file *lower_file);
int ecryptfs_write_headers_virt(char *page_virt,
struct ecryptfs_crypt_stat *crypt_stat,
struct dentry *ecryptfs_dentry);
int ecryptfs_read_headers(struct dentry *ecryptfs_dentry,
struct file *lower_file);
int ecryptfs_new_file_context(struct dentry *ecryptfs_dentry);
int contains_ecryptfs_marker(char *data);
int ecryptfs_read_header_region(char *data, struct dentry *dentry,
struct vfsmount *mnt);
u16 ecryptfs_code_for_cipher_string(struct ecryptfs_crypt_stat *crypt_stat);
int ecryptfs_cipher_code_to_string(char *str, u16 cipher_code);
void ecryptfs_set_default_sizes(struct ecryptfs_crypt_stat *crypt_stat);
int ecryptfs_generate_key_packet_set(char *dest_base,
struct ecryptfs_crypt_stat *crypt_stat,
struct dentry *ecryptfs_dentry,
size_t *len, size_t max);
int process_request_key_err(long err_code);
int
ecryptfs_parse_packet_set(struct ecryptfs_crypt_stat *crypt_stat,
unsigned char *src, struct dentry *ecryptfs_dentry);
int ecryptfs_truncate(struct dentry *dentry, loff_t new_length);
int
ecryptfs_process_cipher(struct crypto_blkcipher **key_tfm, char *cipher_name,
size_t *key_size);
int ecryptfs_inode_test(struct inode *inode, void *candidate_lower_inode);
int ecryptfs_inode_set(struct inode *inode, void *lower_inode);
void ecryptfs_init_inode(struct inode *inode, struct inode *lower_inode);
int ecryptfs_open_lower_file(struct file **lower_file,
struct dentry *lower_dentry,
struct vfsmount *lower_mnt, int flags);
int ecryptfs_close_lower_file(struct file *lower_file);
#endif /* #ifndef ECRYPTFS_KERNEL_H */
