2 * Copyright (C) 2010 The Android Open Source Project
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
8 * http://www.apache.org/licenses/LICENSE-2.0
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.
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
28 #define CRYPT_FOOTER_OFFSET 0x4000
30 #define MAX_CRYPTO_TYPE_NAME_LEN 64
33 #define KEY_TO_SALT_PADDING 32
35 /* definitions of flags in the structure below */
36 #define CRYPT_MNT_KEY_UNENCRYPTED 0x1 /* The key for the partition is not encrypted. */
38 #define CRYPT_MNT_MAGIC 0xD0B5B1C4
40 #define __le32 unsigned int
41 #define __le16 unsigned short int
43 struct crypt_mnt_ftr {
44 __le32 magic; /* See above */
47 __le32 ftr_size; /* in bytes, not including key following */
48 __le32 flags; /* See above */
49 __le32 keysize; /* in bytes */
50 __le32 spare1; /* ignored */
51 __le64 fs_size; /* Size of the encrypted fs, in 512 byte sectors */
52 __le32 failed_decrypt_count; /* count of # of failed attempts to decrypt and
53 mount, set to 0 on successful mount */
54 unsigned char crypto_type_name[MAX_CRYPTO_TYPE_NAME_LEN]; /* The type of encryption
55 needed to decrypt this
56 partition, null terminated */
62 int cryptfs_check_passwd(char *pw);
63 int cryptfs_restart(void);
64 int cryptfs_enable(char *flag, char *passwd);
65 int cryptfs_changepw(char *newpw);