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 45 struct 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 61 struct 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 74 extern "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