715 lines · 25.1 KB · C
RawDownload
/** * 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 <keys/user-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> /* Version verification for shared data structures w/ userspace */#define ECRYPTFS_VERSION_MAJOR 0x00#define ECRYPTFS_VERSION_MINOR 0x04#define ECRYPTFS_SUPPORTED_FILE_VERSION 0x03/* 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_XATTR                 0x00000010#define ECRYPTFS_VERSIONING_MULTKEY               0x00000020#define ECRYPTFS_VERSIONING_DEVMISC               0x00000040#define ECRYPTFS_VERSIONING_MASK (ECRYPTFS_VERSIONING_PASSPHRASE \				  | ECRYPTFS_VERSIONING_PLAINTEXT_PASSTHROUGH \				  | ECRYPTFS_VERSIONING_PUBKEY \				  | ECRYPTFS_VERSIONING_XATTR \				  | ECRYPTFS_VERSIONING_MULTKEY \				  | ECRYPTFS_VERSIONING_DEVMISC)#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 0x03#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_MAX_PKI_NAME_BYTES 16#define ECRYPTFS_DEFAULT_NUM_USERS 4#define ECRYPTFS_MAX_NUM_USERS 32768#define ECRYPTFS_TRANSPORT_NETLINK 0#define ECRYPTFS_TRANSPORT_CONNECTOR 1#define ECRYPTFS_TRANSPORT_RELAYFS 2#define ECRYPTFS_TRANSPORT_MISCDEV 3#define ECRYPTFS_DEFAULT_TRANSPORT ECRYPTFS_TRANSPORT_MISCDEV#define ECRYPTFS_XATTR_NAME "user.ecryptfs" #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 RFC2440_CIPHER_RSA 0x01 /** * 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}; struct ecryptfs_private_key {	u32 key_size;	u32 data_len;	u8 signature[ECRYPTFS_PASSWORD_SIG_SIZE + 1];	char pki_type[ECRYPTFS_MAX_PKI_NAME_BYTES + 1];	u8 data[];}; /* May be a password or a private key */struct ecryptfs_auth_tok {	u16 version; /* 8-bit major and 8-bit minor */	u16 token_type;#define ECRYPTFS_ENCRYPT_ONLY 0x00000001	u32 flags;	struct ecryptfs_session_key session_key;	u8 reserved[32];	union {		struct ecryptfs_password password;		struct ecryptfs_private_key private_key;	} 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_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_DEFAULT_CIPHER "aes"#define ECRYPTFS_DEFAULT_KEY_BYTES 16#define ECRYPTFS_DEFAULT_HASH "md5"#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 MD5_DIGEST_SIZE 16 struct ecryptfs_key_sig {	struct list_head crypt_stat_list;	char keysig[ECRYPTFS_SIG_SIZE_HEX];}; /** * 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#define ECRYPTFS_METADATA_IN_XATTR  0x00000100#define ECRYPTFS_VIEW_AS_ENCRYPTED  0x00000200#define ECRYPTFS_KEY_SET            0x00000400	u32 flags;	unsigned int file_version;	size_t iv_bytes;	size_t num_header_bytes_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];	struct list_head keysig_list;	struct mutex keysig_list_mutex;	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 file *lower_file;	struct mutex lower_file_mutex;	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;}; /** * 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	u32 flags;	struct list_head mount_crypt_stat_list;	struct key *global_auth_tok_key;	struct ecryptfs_auth_tok *global_auth_tok;	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, eCryptfs will use the same ciphers repeatedly throughout * the course of its operations. In order to avoid unnecessarily * destroying and initializing the same cipher repeatedly, eCryptfs * keeps a list of crypto API contexts around to use when needed. */struct ecryptfs_key_tfm {	struct crypto_blkcipher *key_tfm;	size_t key_size;	struct mutex key_tfm_mutex;	struct list_head key_tfm_list;	unsigned char cipher_name[ECRYPTFS_MAX_CIPHER_NAME_SIZE + 1];}; extern struct mutex key_tfm_list_mutex; /** * 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#define ECRYPTFS_XATTR_METADATA_ENABLED        0x00000002#define ECRYPTFS_ENCRYPTED_VIEW_ENABLED        0x00000004#define ECRYPTFS_MOUNT_CRYPT_STAT_INITIALIZED  0x00000008	u32 flags;	struct list_head global_auth_tok_list;	struct mutex global_auth_tok_list_mutex;	size_t num_global_auth_toks;	size_t global_default_cipher_key_size;	unsigned char global_default_cipher_name[ECRYPTFS_MAX_CIPHER_NAME_SIZE						 + 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;}; struct ecryptfs_message {	/* Can never be greater than ecryptfs_message_buf_len */	/* Used to find the parent msg_ctx */	/* Inherits from msg_ctx->index */	u32 index;	u32 data_len;	u8 data[];}; struct ecryptfs_msg_ctx {#define ECRYPTFS_MSG_CTX_STATE_FREE     0x01#define ECRYPTFS_MSG_CTX_STATE_PENDING  0x02#define ECRYPTFS_MSG_CTX_STATE_DONE     0x03#define ECRYPTFS_MSG_CTX_STATE_NO_REPLY 0x04	u8 state;#define ECRYPTFS_MSG_HELO 100#define ECRYPTFS_MSG_QUIT 101#define ECRYPTFS_MSG_REQUEST 102#define ECRYPTFS_MSG_RESPONSE 103	u8 type;	u32 index;	/* Counter converts to a sequence number. Each message sent	 * out for which we expect a response has an associated	 * sequence number. The response must have the same sequence	 * number as the counter for the msg_stc for the message to be	 * valid. */	u32 counter;	size_t msg_size;	struct ecryptfs_message *msg;	struct task_struct *task;	struct list_head node;	struct list_head daemon_out_list;	struct mutex mux;}; extern unsigned int ecryptfs_transport; struct ecryptfs_daemon; struct ecryptfs_daemon {#define ECRYPTFS_DAEMON_IN_READ      0x00000001#define ECRYPTFS_DAEMON_IN_POLL      0x00000002#define ECRYPTFS_DAEMON_ZOMBIE       0x00000004#define ECRYPTFS_DAEMON_MISCDEV_OPEN 0x00000008	u32 flags;	u32 num_queued_msg_ctx;	struct pid *pid;	uid_t euid;	struct user_namespace *user_ns;	struct task_struct *task;	struct mutex mux;	struct list_head msg_ctx_out_queue;	wait_queue_head_t wait;	struct hlist_node euid_chain;}; extern struct mutex ecryptfs_daemon_hash_mux; static inline struct ecryptfs_file_info *ecryptfs_file_to_private(struct file *file){	return (struct ecryptfs_file_info *)file->private_data;} static inline voidecryptfs_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 voidecryptfs_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 voidecryptfs_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 voidecryptfs_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 voidecryptfs_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

Lines 1–500 of 715.