1/*
2 * Copyright (C) 2010 The Android Open Source Project
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 *      http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17/* This structure starts 16,384 bytes before the end of a hardware
18 * partition that is encrypted.
19 * Immediately following this structure is the encrypted key.
20 * The keysize field tells how long the key is, in bytes.
21 * Then there is 32 bytes of padding,
22 * Finally there is the salt used with the user password.
23 * The salt is fixed at 16 bytes long.
24 * Obviously, the filesystem does not include the last 16 kbytes
25 * of the partition.
26 */
27
28#define CRYPT_FOOTER_OFFSET 0x4000
29
30#define MAX_CRYPTO_TYPE_NAME_LEN 64
31
32#define SALT_LEN 16
33#define KEY_TO_SALT_PADDING 32
34
35/* definitions of flags in the structure below */
36#define CRYPT_MNT_KEY_UNENCRYPTED 0x1 /* The key for the partition is not encrypted. */
37#define CRYPT_ENCRYPTION_IN_PROGRESS 0x2 /* Set when starting encryption,
38                                          * clear when done before rebooting */
39
40#define CRYPT_MNT_MAGIC 0xD0B5B1C4
41
42#define __le32 unsigned int
43#define __le16 unsigned short int
44
45struct crypt_mnt_ftr {
46  __le32 magic;		/* See above */
47  __le16 major_version;
48  __le16 minor_version;
49  __le32 ftr_size; 	/* in bytes, not including key following */
50  __le32 flags;		/* See above */
51  __le32 keysize;	/* in bytes */
52  __le32 spare1;	/* ignored */
53  __le64 fs_size;	/* Size of the encrypted fs, in 512 byte sectors */
54  __le32 failed_decrypt_count; /* count of # of failed attempts to decrypt and
55				  mount, set to 0 on successful mount */
56  unsigned char crypto_type_name[MAX_CRYPTO_TYPE_NAME_LEN]; /* The type of encryption
57							       needed to decrypt this
58							       partition, null terminated */
59};
60
61struct volume_info {
62   unsigned int size;
63   unsigned int flags;
64   struct crypt_mnt_ftr crypt_ftr;
65   char mnt_point[256];
66   char blk_dev[256];
67   char crypto_blkdev[256];
68   char label[256];
69};
70#define VOL_NONREMOVABLE 0x1
71#define VOL_ENCRYPTABLE  0x2
72
73#ifdef __cplusplus
74extern "C" {
75#endif
76  int cryptfs_crypto_complete(void);
77  int cryptfs_check_passwd(char *pw);
78  int cryptfs_verify_passwd(char *newpw);
79  int cryptfs_restart(void);
80  int cryptfs_enable(char *flag, char *passwd);
81  int cryptfs_changepw(char *newpw);
82  int cryptfs_setup_volume(const char *label, int major, int minor,
83                           char *crypto_dev_path, unsigned int max_pathlen,
84                           int *new_major, int *new_minor);
85  int cryptfs_revert_volume(const char *label);
86#ifdef __cplusplus
87}
88#endif
89
90