diff options
Diffstat (limited to 'crypto/jb/cryptfs.h')
| -rw-r--r-- | crypto/jb/cryptfs.h | 89 |
1 files changed, 78 insertions, 11 deletions
diff --git a/crypto/jb/cryptfs.h b/crypto/jb/cryptfs.h index 1c1bc1aea..162159eb0 100644 --- a/crypto/jb/cryptfs.h +++ b/crypto/jb/cryptfs.h @@ -15,22 +15,31 @@ */ /* This structure starts 16,384 bytes before the end of a hardware - * partition that is encrypted. - * Immediately following this structure is the encrypted key. - * The keysize field tells how long the key is, in bytes. - * Then there is 32 bytes of padding, - * Finally there is the salt used with the user password. - * The salt is fixed at 16 bytes long. + * partition that is encrypted, or in a separate partition. It's location + * is specified by a property set in init.<device>.rc. + * The structure allocates 48 bytes for a key, but the real key size is + * specified in the struct. Currently, the code is hardcoded to use 128 + * bit keys. + * The fields after salt are only valid in rev 1.1 and later stuctures. * Obviously, the filesystem does not include the last 16 kbytes - * of the partition. + * of the partition if the crypt_mnt_ftr lives at the end of the + * partition. */ +#include <cutils/properties.h> + +/* The current cryptfs version */ +#define CURRENT_MAJOR_VERSION 1 +#define CURRENT_MINOR_VERSION 2 + #define CRYPT_FOOTER_OFFSET 0x4000 +#define CRYPT_FOOTER_TO_PERSIST_OFFSET 0x1000 +#define CRYPT_PERSIST_DATA_SIZE 0x1000 #define MAX_CRYPTO_TYPE_NAME_LEN 64 +#define MAX_KEY_LEN 48 #define SALT_LEN 16 -#define KEY_TO_SALT_PADDING 32 /* definitions of flags in the structure below */ #define CRYPT_MNT_KEY_UNENCRYPTED 0x1 /* The key for the partition is not encrypted. */ @@ -38,9 +47,18 @@ * clear when done before rebooting */ #define CRYPT_MNT_MAGIC 0xD0B5B1C4 +#define PERSIST_DATA_MAGIC 0xE950CD44 + +#define SCRYPT_PROP "ro.crypto.scrypt_params" +#define SCRYPT_DEFAULTS { 15, 3, 1 } + +/* Key Derivation Function algorithms */ +#define KDF_PBKDF2 1 +#define KDF_SCRYPT 2 #define __le32 unsigned int -#define __le16 unsigned short int +#define __le16 unsigned short int +#define __le8 unsigned char struct crypt_mnt_ftr { __le32 magic; /* See above */ @@ -56,6 +74,48 @@ struct crypt_mnt_ftr { unsigned char crypto_type_name[MAX_CRYPTO_TYPE_NAME_LEN]; /* The type of encryption needed to decrypt this partition, null terminated */ + __le32 spare2; /* ignored */ + unsigned char master_key[MAX_KEY_LEN]; /* The encrypted key for decrypting the filesystem */ + unsigned char salt[SALT_LEN]; /* The salt used for this encryption */ + __le64 persist_data_offset[2]; /* Absolute offset to both copies of crypt_persist_data + * on device with that info, either the footer of the + * real_blkdevice or the metadata partition. */ + + __le32 persist_data_size; /* The number of bytes allocated to each copy of the + * persistent data table*/ + + __le8 kdf_type; /* The key derivation function used. */ + + /* scrypt parameters. See www.tarsnap.com/scrypt/scrypt.pdf */ + __le8 N_factor; /* (1 << N) */ + __le8 r_factor; /* (1 << r) */ + __le8 p_factor; /* (1 << p) */ +}; + +/* Persistant data that should be available before decryption. + * Things like airplane mode, locale and timezone are kept + * here and can be retrieved by the CryptKeeper UI to properly + * configure the phone before asking for the password + * This is only valid if the major and minor version above + * is set to 1.1 or higher. + * + * This is a 4K structure. There are 2 copies, and the code alternates + * writing one and then clearing the previous one. The reading + * code reads the first valid copy it finds, based on the magic number. + * The absolute offset to the first of the two copies is kept in rev 1.1 + * and higher crypt_mnt_ftr structures. + */ +struct crypt_persist_entry { + char key[PROPERTY_KEY_MAX]; + char val[PROPERTY_VALUE_MAX]; +}; + +/* Should be exactly 4K in size */ +struct crypt_persist_data { + __le32 persist_magic; + __le32 persist_valid_entries; + __le32 persist_spare[30]; + struct crypt_persist_entry persist_entry[0]; }; struct volume_info { @@ -67,12 +127,17 @@ struct volume_info { char crypto_blkdev[256]; char label[256]; }; -#define VOL_NONREMOVABLE 0x1 -#define VOL_ENCRYPTABLE 0x2 +#define VOL_NONREMOVABLE 0x1 +#define VOL_ENCRYPTABLE 0x2 +#define VOL_PRIMARY 0x4 +#define VOL_PROVIDES_ASEC 0x8 #ifdef __cplusplus extern "C" { #endif + + typedef void (*kdf_func)(char *passwd, unsigned char *salt, unsigned char *ikey, void *params); + int cryptfs_crypto_complete(void); int cryptfs_check_passwd(char *pw); int cryptfs_verify_passwd(char *newpw); @@ -83,6 +148,8 @@ extern "C" { char *crypto_dev_path, unsigned int max_pathlen, int *new_major, int *new_minor); int cryptfs_revert_volume(const char *label); + int cryptfs_getfield(char *fieldname, char *value, int len); + int cryptfs_setfield(char *fieldname, char *value); #ifdef __cplusplus } #endif |