/* * linux/fs/f2fs/f2fs_crypto.h * * Copied from linux/fs/ext4/ext4_crypto.h * * Copyright (C) 2015, Google, Inc. * * This contains encryption header content for f2fs * * Written by Michael Halcrow, 2015. * Modified by Jaegeuk Kim, 2015. */ #ifndef _F2FS_CRYPTO_H #define _F2FS_CRYPTO_H #include #define F2FS_KEY_DESCRIPTOR_SIZE 8 /* Policy provided via an ioctl on the topmost directory */ struct f2fs_encryption_policy { char version; char contents_encryption_mode; char filenames_encryption_mode; char flags; char master_key_descriptor[F2FS_KEY_DESCRIPTOR_SIZE]; } __attribute__((__packed__)); #define F2FS_ENCRYPTION_CONTEXT_FORMAT_V1 1 #define F2FS_KEY_DERIVATION_NONCE_SIZE 16 #define F2FS_POLICY_FLAGS_PAD_4 0x00 #define F2FS_POLICY_FLAGS_PAD_8 0x01 #define F2FS_POLICY_FLAGS_PAD_16 0x02 #define F2FS_POLICY_FLAGS_PAD_32 0x03 #define F2FS_POLICY_FLAGS_PAD_MASK 0x03 #define F2FS_POLICY_FLAGS_VALID 0x03 /** * 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 f2fs_encryption_context { char format; char contents_encryption_mode; char filenames_encryption_mode; char flags; char master_key_descriptor[F2FS_KEY_DESCRIPTOR_SIZE]; char nonce[F2FS_KEY_DERIVATION_NONCE_SIZE]; } __attribute__((__packed__)); /* Encryption parameters */ #define F2FS_XTS_TWEAK_SIZE 16 #define F2FS_AES_128_ECB_KEY_SIZE 16 #define F2FS_AES_256_GCM_KEY_SIZE 32 #define F2FS_AES_256_CBC_KEY_SIZE 32 #define F2FS_AES_256_CTS_KEY_SIZE 32 #define F2FS_AES_256_XTS_KEY_SIZE 64 #define F2FS_MAX_KEY_SIZE 64 #define F2FS_KEY_DESC_PREFIX "f2fs:" #define F2FS_KEY_DESC_PREFIX_SIZE 5 struct f2fs_encryption_key { __u32 mode; char raw[F2FS_MAX_KEY_SIZE]; __u32 size; } __attribute__((__packed__)); struct f2fs_crypt_info { char ci_data_mode; char ci_filename_mode; char ci_flags; struct crypto_ablkcipher *ci_ctfm; struct key *ci_keyring_key; char ci_master_key[F2FS_KEY_DESCRIPTOR_SIZE]; }; #define F2FS_CTX_REQUIRES_FREE_ENCRYPT_FL 0x00000001 #define F2FS_BOUNCE_PAGE_REQUIRES_FREE_ENCRYPT_FL 0x00000002 #define F2FS_WRITE_PATH_FL 0x00000004 struct f2fs_crypto_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 */ }; char flags; /* Flags */ }; struct f2fs_completion_result { struct completion completion; int res; }; #define DECLARE_F2FS_COMPLETION_RESULT(ecr) \ struct f2fs_completion_result ecr = { \ COMPLETION_INITIALIZER((ecr).completion), 0 } static inline int f2fs_encryption_key_size(int mode) { switch (mode) { case F2FS_ENCRYPTION_MODE_AES_256_XTS: return F2FS_AES_256_XTS_KEY_SIZE; case F2FS_ENCRYPTION_MODE_AES_256_GCM: return F2FS_AES_256_GCM_KEY_SIZE; case F2FS_ENCRYPTION_MODE_AES_256_CBC: return F2FS_AES_256_CBC_KEY_SIZE; case F2FS_ENCRYPTION_MODE_AES_256_CTS: return F2FS_AES_256_CTS_KEY_SIZE; default: BUG(); } return 0; } #define F2FS_FNAME_NUM_SCATTER_ENTRIES 4 #define F2FS_CRYPTO_BLOCK_SIZE 16 #define F2FS_FNAME_CRYPTO_DIGEST_SIZE 32 /** * For encrypted symlinks, the ciphertext length is stored at the beginning * of the string in little-endian format. */ struct f2fs_encrypted_symlink_data { __le16 len; char encrypted_path[1]; } __attribute__((__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 encrypted_symlink_data_len(u32 l) { return (l + sizeof(struct f2fs_encrypted_symlink_data) - 1); } #endif /* _F2FS_CRYPTO_H */