/** * 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 * * 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 #include #include #include #include /* 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 */