im.actor.api.crypto

Class Crypto

java.lang.Object

im.actor.api.crypto.Crypto

public class Crypto
extends java.lang.Object

Class contains methods for creating all types of Ciphers and SecureRandom instances for message and file encryption

Most parameters are taken from WhisperSystem's TextSecure.

Field Summary

Fields

Modifier and Type	Field and Description
protected static char[]	hexArray

Constructor Summary

Constructors

Constructor and Description
Crypto()

Method Summary

Modifier and Type	Method and Description
static javax.crypto.Cipher	createAESCipher() Creating AES-CBC with PKCS#5 Padding scheme.
static javax.crypto.Mac	createHmacSHA256() Creating HMAC-SHA256.
static javax.crypto.Cipher	createRSACipher() Creating RSA with OAEP-SHA1-MGF1 Padding scheme This cipher used for encryption of AES auth of message
static byte[]	generateSeed(int size) Generating of secure seed
static long	generateSessionId() Generation of session id for MTProto
static java.security.SecureRandom	getSecureRandom() Creating SecureRandom instance
static java.lang.String	hex(byte[] bytes) Calculating lowcase hex string
static byte[]	SHA1(byte[] data) Calculating SHA1
static byte[]	SHA256(byte[] data) Calculating SHA256

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

hexArray

protected static final char[] hexArray

Constructor Detail

Crypto

public Crypto()

Method Detail

getSecureRandom

public static java.security.SecureRandom getSecureRandom()

Creating SecureRandom instance

Returns:

the SecureRandom

createAESCipher

public static javax.crypto.Cipher createAESCipher()

Creating AES-CBC with PKCS#5 Padding scheme. This mode used in many places for file and message encryption

Returns:

AES Cipher

createRSACipher

public static javax.crypto.Cipher createRSACipher()

Creating RSA with OAEP-SHA1-MGF1 Padding scheme This cipher used for encryption of AES auth of message

Returns:

the RSA Cipher

createHmacSHA256

public static javax.crypto.Mac createHmacSHA256()

Creating HMAC-SHA256. Used in file encryption

Returns:

the HMAC-SHA256

generateSeed

public static byte[] generateSeed(int size)

Generating of secure seed

Parameters:

size - seed zie

Returns:

generated random bytes

generateSessionId

public static long generateSessionId()

Generation of session id for MTProto

Returns:

session id

SHA256

public static byte[] SHA256(byte[] data)

Calculating SHA256

Parameters:

data - source data

Returns:

SHA256 of data

SHA1

public static byte[] SHA1(byte[] data)

Calculating SHA1

Parameters:

data - source data

Returns:

SHA1 of data

hex

public static java.lang.String hex(byte[] bytes)

Calculating lowcase hex string

Parameters:

bytes - data for hex

Returns:

hex string