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Diffstat (limited to 'ubifs-utils/common/fscrypt.h')
| -rw-r--r-- | ubifs-utils/common/fscrypt.h | 171 |
1 files changed, 171 insertions, 0 deletions
diff --git a/ubifs-utils/common/fscrypt.h b/ubifs-utils/common/fscrypt.h new file mode 100644 index 0000000..ff3d326 --- /dev/null +++ b/ubifs-utils/common/fscrypt.h @@ -0,0 +1,171 @@ +/* + * Copyright (C) 2017 sigma star gmbh + * + * This program is free software; you can redistribute it and/or modify it + * under the terms of the GNU General Public License version 2 as published by + * the Free Software Foundation. + * + * 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., 51 + * Franklin St, Fifth Floor, Boston, MA 02110-1301 USA + * + * Authors: Richard Weinberger <richard@sigma-star.at> + * David Oberhollenzer <david.oberhollenzer@sigma-star.at> + */ + +#ifndef FSCRYPT_H +#define FSCRYPT_H + + +#include "mkfs.ubifs.h" +#include <sys/types.h> +#include "crypto.h" + +#ifndef FS_KEY_DESCRIPTOR_SIZE +#define FS_KEY_DESCRIPTOR_SIZE 8 +#endif +#define FS_ENCRYPTION_CONTEXT_FORMAT_V1 1 +#define FS_KEY_DERIVATION_NONCE_SIZE 16 + +#ifndef FS_ENCRYPTION_MODE_AES_256_XTS +#define FS_ENCRYPTION_MODE_AES_256_XTS 1 +#endif + +#ifndef FS_ENCRYPTION_MODE_AES_256_CTS +#define FS_ENCRYPTION_MODE_AES_256_CTS 4 +#endif + +#ifndef FS_ENCRYPTION_MODE_AES_128_CBC +#define FS_ENCRYPTION_MODE_AES_128_CBC 5 +#endif + +#ifndef FS_ENCRYPTION_MODE_AES_128_CTS +#define FS_ENCRYPTION_MODE_AES_128_CTS 6 +#endif + +#ifndef FS_POLICY_FLAGS_VALID +#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 +#endif + +#define FS_CRYPTO_BLOCK_SIZE 16 + +/** + * 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]; +} __attribute__((packed)); + +/** + * 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]; +} __attribute__((packed)); + + +#ifndef FS_MAX_KEY_SIZE +#define FS_MAX_KEY_SIZE 64 +#endif + +#ifndef FS_IV_SIZE +#define FS_IV_SIZE 16 +#endif + +#ifdef WITH_CRYPTO +unsigned char *calc_fscrypt_subkey(struct fscrypt_context *fctx); +struct fscrypt_context *inherit_fscrypt_context(struct fscrypt_context *fctx); +void free_fscrypt_context(struct fscrypt_context *fctx); +unsigned int fscrypt_fname_encrypted_size(struct fscrypt_context *fctx, + unsigned int ilen); +int encrypt_path(void **outbuf, void *data, unsigned int data_len, + unsigned int max_namelen, struct fscrypt_context *fctx); +int encrypt_data_node(struct fscrypt_context *fctx, unsigned int block_no, + struct ubifs_data_node *dn, size_t length); +struct fscrypt_context *init_fscrypt_context(const char *cipher_name, + unsigned int flags, + const char *key_file, + const char *key_descriptor); +#else +static inline struct fscrypt_context *init_fscrypt_context( + const char *cipher_name, + unsigned int flags, + const char *key_file, + const char *key_descriptor) +{ + (void)cipher_name; + (void)flags; + (void)key_file; + (void)key_descriptor; + + assert(0); + return NULL; +} + +static inline void free_fscrypt_context(struct fscrypt_context *fctx) +{ + (void)fctx; + + assert(!fctx); +} + +static inline int encrypt_path(void **outbuf, void *data, unsigned int data_len, + unsigned int max_namelen, struct fscrypt_context *fctx) +{ + (void)outbuf; + (void)data; + (void)data_len; + (void)max_namelen; + (void)fctx; + + assert(0); + return -1; +} + +static inline int encrypt_data_node(struct fscrypt_context *fctx, unsigned int block_no, + struct ubifs_data_node *dn, size_t length) +{ + (void)fctx; + (void)block_no; + (void)dn; + (void)length; + + assert(0); + return -1; +} + +static inline struct fscrypt_context *inherit_fscrypt_context(struct fscrypt_context *fctx) +{ + (void)fctx; + + assert(!fctx); + return NULL; +} +#endif /* WITH_CRYPTO */ +#endif /* FSCRYPT_H */ + |