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Diffstat (limited to 'fs/ecryptfs/ecryptfs_kernel.h')
| -rw-r--r-- | fs/ecryptfs/ecryptfs_kernel.h | 482 |
1 files changed, 482 insertions, 0 deletions
diff --git a/fs/ecryptfs/ecryptfs_kernel.h b/fs/ecryptfs/ecryptfs_kernel.h new file mode 100644 index 000000000000..872c9958531a --- /dev/null +++ b/fs/ecryptfs/ecryptfs_kernel.h @@ -0,0 +1,482 @@ +/** + * 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/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_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_tfm *tfm; + struct crypto_tfm *md5_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_md5_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 dentry *wdi_dentry; + struct vfsmount *lower_mnt; + 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_tfm *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)->wdi_dentry; +} + +static inline void +ecryptfs_set_dentry_lower(struct dentry *dentry, struct dentry *lower_dentry) +{ + ((struct ecryptfs_dentry_info *)dentry->d_fsdata)->wdi_dentry = + lower_dentry; +} + +static inline struct vfsmount * +ecryptfs_dentry_to_lower_mnt(struct dentry *dentry) +{ + return ((struct ecryptfs_dentry_info *)dentry->d_fsdata)->lower_mnt; +} + +static inline void +ecryptfs_set_dentry_lower_mnt(struct dentry *dentry, struct vfsmount *lower_mnt) +{ + ((struct ecryptfs_dentry_info *)dentry->d_fsdata)->lower_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_copy_attr_atime(struct inode *dest, const struct inode *src); +void ecryptfs_copy_attr_all(struct inode *dest, const struct inode *src); +void ecryptfs_copy_inode_size(struct inode *dst, const struct inode *src); +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_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_tfm **tfm, struct crypto_tfm **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); + +#endif /* #ifndef ECRYPTFS_KERNEL_H */ |
