diff options
Diffstat (limited to 'kernel/fs/f2fs/f2fs_crypto.h')
-rw-r--r-- | kernel/fs/f2fs/f2fs_crypto.h | 151 |
1 files changed, 151 insertions, 0 deletions
diff --git a/kernel/fs/f2fs/f2fs_crypto.h b/kernel/fs/f2fs/f2fs_crypto.h new file mode 100644 index 000000000..c2c1c2b63 --- /dev/null +++ b/kernel/fs/f2fs/f2fs_crypto.h @@ -0,0 +1,151 @@ +/* + * 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 <linux/fs.h> + +#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_WRITE_PATH_FL 0x00000002 + +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 */ |