| /* |
| * General per-file encryption definition |
| * |
| * Copyright (C) 2015, Google, Inc. |
| * |
| * Written by Michael Halcrow, 2015. |
| * Modified by Jaegeuk Kim, 2015. |
| */ |
| |
| #ifndef _LINUX_FSCRYPTO_H |
| #define _LINUX_FSCRYPTO_H |
| |
| #include <linux/key.h> |
| #include <linux/fs.h> |
| #include <linux/mm.h> |
| #include <linux/bio.h> |
| #include <linux/dcache.h> |
| #include <crypto/skcipher.h> |
| #include <uapi/linux/fs.h> |
| |
| #define FS_KEY_DERIVATION_NONCE_SIZE 16 |
| #define FS_ENCRYPTION_CONTEXT_FORMAT_V1 1 |
| |
| #define FS_POLICY_FLAGS_PAD_4 0x00 |
| #define FS_POLICY_FLAGS_PAD_8 0x01 |
| #define FS_POLICY_FLAGS_PAD_16 0x02 |
| #define FS_POLICY_FLAGS_PAD_32 0x03 |
| #define FS_POLICY_FLAGS_PAD_MASK 0x03 |
| #define FS_POLICY_FLAGS_VALID 0x03 |
| |
| /* Encryption algorithms */ |
| #define FS_ENCRYPTION_MODE_INVALID 0 |
| #define FS_ENCRYPTION_MODE_AES_256_XTS 1 |
| #define FS_ENCRYPTION_MODE_AES_256_GCM 2 |
| #define FS_ENCRYPTION_MODE_AES_256_CBC 3 |
| #define FS_ENCRYPTION_MODE_AES_256_CTS 4 |
| |
| /** |
| * Encryption context for inode |
| * |
| * Protector format: |
| * 1 byte: Protector format (1 = this version) |
| * 1 byte: File contents encryption mode |
| * 1 byte: File names encryption mode |
| * 1 byte: Flags |
| * 8 bytes: Master Key descriptor |
| * 16 bytes: Encryption Key derivation nonce |
| */ |
| struct fscrypt_context { |
| u8 format; |
| u8 contents_encryption_mode; |
| u8 filenames_encryption_mode; |
| u8 flags; |
| u8 master_key_descriptor[FS_KEY_DESCRIPTOR_SIZE]; |
| u8 nonce[FS_KEY_DERIVATION_NONCE_SIZE]; |
| } __packed; |
| |
| /* Encryption parameters */ |
| #define FS_XTS_TWEAK_SIZE 16 |
| #define FS_AES_128_ECB_KEY_SIZE 16 |
| #define FS_AES_256_GCM_KEY_SIZE 32 |
| #define FS_AES_256_CBC_KEY_SIZE 32 |
| #define FS_AES_256_CTS_KEY_SIZE 32 |
| #define FS_AES_256_XTS_KEY_SIZE 64 |
| #define FS_MAX_KEY_SIZE 64 |
| |
| #define FS_KEY_DESC_PREFIX "fscrypt:" |
| #define FS_KEY_DESC_PREFIX_SIZE 8 |
| |
| /* This is passed in from userspace into the kernel keyring */ |
| struct fscrypt_key { |
| u32 mode; |
| u8 raw[FS_MAX_KEY_SIZE]; |
| u32 size; |
| } __packed; |
| |
| struct fscrypt_info { |
| u8 ci_data_mode; |
| u8 ci_filename_mode; |
| u8 ci_flags; |
| struct crypto_skcipher *ci_ctfm; |
| struct key *ci_keyring_key; |
| u8 ci_master_key[FS_KEY_DESCRIPTOR_SIZE]; |
| }; |
| |
| #define FS_CTX_REQUIRES_FREE_ENCRYPT_FL 0x00000001 |
| #define FS_WRITE_PATH_FL 0x00000002 |
| |
| struct fscrypt_ctx { |
| union { |
| struct { |
| struct page *bounce_page; /* Ciphertext page */ |
| struct page *control_page; /* Original page */ |
| } w; |
| struct { |
| struct bio *bio; |
| struct work_struct work; |
| } r; |
| struct list_head free_list; /* Free list */ |
| }; |
| u8 flags; /* Flags */ |
| u8 mode; /* Encryption mode for tfm */ |
| }; |
| |
| struct fscrypt_completion_result { |
| struct completion completion; |
| int res; |
| }; |
| |
| #define DECLARE_FS_COMPLETION_RESULT(ecr) \ |
| struct fscrypt_completion_result ecr = { \ |
| COMPLETION_INITIALIZER((ecr).completion), 0 } |
| |
| #define FS_FNAME_NUM_SCATTER_ENTRIES 4 |
| #define FS_CRYPTO_BLOCK_SIZE 16 |
| #define FS_FNAME_CRYPTO_DIGEST_SIZE 32 |
| |
| /** |
| * For encrypted symlinks, the ciphertext length is stored at the beginning |
| * of the string in little-endian format. |
| */ |
| struct fscrypt_symlink_data { |
| __le16 len; |
| char encrypted_path[1]; |
| } __packed; |
| |
| /** |
| * This function is used to calculate the disk space required to |
| * store a filename of length l in encrypted symlink format. |
| */ |
| static inline u32 fscrypt_symlink_data_len(u32 l) |
| { |
| if (l < FS_CRYPTO_BLOCK_SIZE) |
| l = FS_CRYPTO_BLOCK_SIZE; |
| return (l + sizeof(struct fscrypt_symlink_data) - 1); |
| } |
| |
| struct fscrypt_str { |
| unsigned char *name; |
| u32 len; |
| }; |
| |
| struct fscrypt_name { |
| const struct qstr *usr_fname; |
| struct fscrypt_str disk_name; |
| u32 hash; |
| u32 minor_hash; |
| struct fscrypt_str crypto_buf; |
| }; |
| |
| #define FSTR_INIT(n, l) { .name = n, .len = l } |
| #define FSTR_TO_QSTR(f) QSTR_INIT((f)->name, (f)->len) |
| #define fname_name(p) ((p)->disk_name.name) |
| #define fname_len(p) ((p)->disk_name.len) |
| |
| /* |
| * crypto opertions for filesystems |
| */ |
| struct fscrypt_operations { |
| int (*get_context)(struct inode *, void *, size_t); |
| int (*key_prefix)(struct inode *, u8 **); |
| int (*prepare_context)(struct inode *); |
| int (*set_context)(struct inode *, const void *, size_t, void *); |
| int (*dummy_context)(struct inode *); |
| bool (*is_encrypted)(struct inode *); |
| bool (*empty_dir)(struct inode *); |
| unsigned (*max_namelen)(struct inode *); |
| }; |
| |
| static inline bool fscrypt_dummy_context_enabled(struct inode *inode) |
| { |
| if (inode->i_sb->s_cop->dummy_context && |
| inode->i_sb->s_cop->dummy_context(inode)) |
| return true; |
| return false; |
| } |
| |
| static inline bool fscrypt_valid_contents_enc_mode(u32 mode) |
| { |
| return (mode == FS_ENCRYPTION_MODE_AES_256_XTS); |
| } |
| |
| static inline bool fscrypt_valid_filenames_enc_mode(u32 mode) |
| { |
| return (mode == FS_ENCRYPTION_MODE_AES_256_CTS); |
| } |
| |
| static inline bool fscrypt_is_dot_dotdot(const struct qstr *str) |
| { |
| if (str->len == 1 && str->name[0] == '.') |
| return true; |
| |
| if (str->len == 2 && str->name[0] == '.' && str->name[1] == '.') |
| return true; |
| |
| return false; |
| } |
| |
| static inline struct page *fscrypt_control_page(struct page *page) |
| { |
| #if IS_ENABLED(CONFIG_FS_ENCRYPTION) |
| return ((struct fscrypt_ctx *)page_private(page))->w.control_page; |
| #else |
| WARN_ON_ONCE(1); |
| return ERR_PTR(-EINVAL); |
| #endif |
| } |
| |
| static inline int fscrypt_has_encryption_key(struct inode *inode) |
| { |
| #if IS_ENABLED(CONFIG_FS_ENCRYPTION) |
| return (inode->i_crypt_info != NULL); |
| #else |
| return 0; |
| #endif |
| } |
| |
| static inline void fscrypt_set_encrypted_dentry(struct dentry *dentry) |
| { |
| #if IS_ENABLED(CONFIG_FS_ENCRYPTION) |
| spin_lock(&dentry->d_lock); |
| dentry->d_flags |= DCACHE_ENCRYPTED_WITH_KEY; |
| spin_unlock(&dentry->d_lock); |
| #endif |
| } |
| |
| #if IS_ENABLED(CONFIG_FS_ENCRYPTION) |
| extern const struct dentry_operations fscrypt_d_ops; |
| #endif |
| |
| static inline void fscrypt_set_d_op(struct dentry *dentry) |
| { |
| #if IS_ENABLED(CONFIG_FS_ENCRYPTION) |
| d_set_d_op(dentry, &fscrypt_d_ops); |
| #endif |
| } |
| |
| #if IS_ENABLED(CONFIG_FS_ENCRYPTION) |
| /* crypto.c */ |
| extern struct kmem_cache *fscrypt_info_cachep; |
| int fscrypt_initialize(void); |
| |
| extern struct fscrypt_ctx *fscrypt_get_ctx(struct inode *, gfp_t); |
| extern void fscrypt_release_ctx(struct fscrypt_ctx *); |
| extern struct page *fscrypt_encrypt_page(struct inode *, struct page *, gfp_t); |
| extern int fscrypt_decrypt_page(struct page *); |
| extern void fscrypt_decrypt_bio_pages(struct fscrypt_ctx *, struct bio *); |
| extern void fscrypt_pullback_bio_page(struct page **, bool); |
| extern void fscrypt_restore_control_page(struct page *); |
| extern int fscrypt_zeroout_range(struct inode *, pgoff_t, sector_t, |
| unsigned int); |
| /* policy.c */ |
| extern int fscrypt_process_policy(struct file *, const struct fscrypt_policy *); |
| extern int fscrypt_get_policy(struct inode *, struct fscrypt_policy *); |
| extern int fscrypt_has_permitted_context(struct inode *, struct inode *); |
| extern int fscrypt_inherit_context(struct inode *, struct inode *, |
| void *, bool); |
| /* keyinfo.c */ |
| extern int get_crypt_info(struct inode *); |
| extern int fscrypt_get_encryption_info(struct inode *); |
| extern void fscrypt_put_encryption_info(struct inode *, struct fscrypt_info *); |
| |
| /* fname.c */ |
| extern int fscrypt_setup_filename(struct inode *, const struct qstr *, |
| int lookup, struct fscrypt_name *); |
| extern void fscrypt_free_filename(struct fscrypt_name *); |
| extern u32 fscrypt_fname_encrypted_size(struct inode *, u32); |
| extern int fscrypt_fname_alloc_buffer(struct inode *, u32, |
| struct fscrypt_str *); |
| extern void fscrypt_fname_free_buffer(struct fscrypt_str *); |
| extern int fscrypt_fname_disk_to_usr(struct inode *, u32, u32, |
| const struct fscrypt_str *, struct fscrypt_str *); |
| extern int fscrypt_fname_usr_to_disk(struct inode *, const struct qstr *, |
| struct fscrypt_str *); |
| #endif |
| |
| /* crypto.c */ |
| static inline struct fscrypt_ctx *fscrypt_notsupp_get_ctx(struct inode *i, |
| gfp_t f) |
| { |
| return ERR_PTR(-EOPNOTSUPP); |
| } |
| |
| static inline void fscrypt_notsupp_release_ctx(struct fscrypt_ctx *c) |
| { |
| return; |
| } |
| |
| static inline struct page *fscrypt_notsupp_encrypt_page(struct inode *i, |
| struct page *p, gfp_t f) |
| { |
| return ERR_PTR(-EOPNOTSUPP); |
| } |
| |
| static inline int fscrypt_notsupp_decrypt_page(struct page *p) |
| { |
| return -EOPNOTSUPP; |
| } |
| |
| static inline void fscrypt_notsupp_decrypt_bio_pages(struct fscrypt_ctx *c, |
| struct bio *b) |
| { |
| return; |
| } |
| |
| static inline void fscrypt_notsupp_pullback_bio_page(struct page **p, bool b) |
| { |
| return; |
| } |
| |
| static inline void fscrypt_notsupp_restore_control_page(struct page *p) |
| { |
| return; |
| } |
| |
| static inline int fscrypt_notsupp_zeroout_range(struct inode *i, pgoff_t p, |
| sector_t s, unsigned int f) |
| { |
| return -EOPNOTSUPP; |
| } |
| |
| /* policy.c */ |
| static inline int fscrypt_notsupp_process_policy(struct file *f, |
| const struct fscrypt_policy *p) |
| { |
| return -EOPNOTSUPP; |
| } |
| |
| static inline int fscrypt_notsupp_get_policy(struct inode *i, |
| struct fscrypt_policy *p) |
| { |
| return -EOPNOTSUPP; |
| } |
| |
| static inline int fscrypt_notsupp_has_permitted_context(struct inode *p, |
| struct inode *i) |
| { |
| return 0; |
| } |
| |
| static inline int fscrypt_notsupp_inherit_context(struct inode *p, |
| struct inode *i, void *v, bool b) |
| { |
| return -EOPNOTSUPP; |
| } |
| |
| /* keyinfo.c */ |
| static inline int fscrypt_notsupp_get_encryption_info(struct inode *i) |
| { |
| return -EOPNOTSUPP; |
| } |
| |
| static inline void fscrypt_notsupp_put_encryption_info(struct inode *i, |
| struct fscrypt_info *f) |
| { |
| return; |
| } |
| |
| /* fname.c */ |
| static inline int fscrypt_notsupp_setup_filename(struct inode *dir, |
| const struct qstr *iname, |
| int lookup, struct fscrypt_name *fname) |
| { |
| if (dir->i_sb->s_cop->is_encrypted(dir)) |
| return -EOPNOTSUPP; |
| |
| memset(fname, 0, sizeof(struct fscrypt_name)); |
| fname->usr_fname = iname; |
| fname->disk_name.name = (unsigned char *)iname->name; |
| fname->disk_name.len = iname->len; |
| return 0; |
| } |
| |
| static inline void fscrypt_notsupp_free_filename(struct fscrypt_name *fname) |
| { |
| return; |
| } |
| |
| static inline u32 fscrypt_notsupp_fname_encrypted_size(struct inode *i, u32 s) |
| { |
| /* never happens */ |
| WARN_ON(1); |
| return 0; |
| } |
| |
| static inline int fscrypt_notsupp_fname_alloc_buffer(struct inode *inode, |
| u32 ilen, struct fscrypt_str *crypto_str) |
| { |
| return -EOPNOTSUPP; |
| } |
| |
| static inline void fscrypt_notsupp_fname_free_buffer(struct fscrypt_str *c) |
| { |
| return; |
| } |
| |
| static inline int fscrypt_notsupp_fname_disk_to_usr(struct inode *inode, |
| u32 hash, u32 minor_hash, |
| const struct fscrypt_str *iname, |
| struct fscrypt_str *oname) |
| { |
| return -EOPNOTSUPP; |
| } |
| |
| static inline int fscrypt_notsupp_fname_usr_to_disk(struct inode *inode, |
| const struct qstr *iname, |
| struct fscrypt_str *oname) |
| { |
| return -EOPNOTSUPP; |
| } |
| #endif /* _LINUX_FSCRYPTO_H */ |