org.telegram.mtproto.secure.aes

Class AESFastEngine

java.lang.Object

org.telegram.mtproto.secure.aes.AESFastEngine

public class AESFastEngine
extends Object

An implementation of the AES (Rijndael), from FIPS-197.

For further details see: http://csrc.nist.gov/encryption/aes/.

This implementation is based on optimizations from Dr. Brian Gladman's paper and C code at http://fp.gladman.plus.com/cryptography_technology/rijndael/

There are three levels of tradeoff of speed vs memory Because java has no preprocessor, they are written as three separate classes from which to choose

The fastest uses 8Kbytes of static tables to precompute round calculations, 4 256 word tables for encryption and 4 for decryption.

The middle performance version uses only one 256 word table for each, for a total of 2Kbytes, adding 12 rotate operations per round to compute the values contained in the other tables from the contents of the first

The slowest version uses no static tables at all and computes the values in each round

This file contains the fast version with 8Kbytes of static tables for round precomputation

Constructor Summary

Constructors

Constructor and Description
AESFastEngine() default constructor - 128 bit block size.

Method Summary

Modifier and Type	Method and Description
String	getAlgorithmName()
int	getBlockSize()
void	init(boolean forEncryption, KeyParameter params) initialise an AES cipher.
int	processBlock(byte[] in, int inOff, byte[] out, int outOff)
void	reset()

Methods inherited from class java.lang.Object

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

Constructor Detail

AESFastEngine

public AESFastEngine()

default constructor - 128 bit block size.

Method Detail

init

public void init(boolean forEncryption,
                 KeyParameter params)

initialise an AES cipher.

Parameters:

forEncryption - whether or not we are for encryption.

params - the parameters required to set up the cipher.

Throws:

IllegalArgumentException - if the params argument is inappropriate.

getAlgorithmName

public String getAlgorithmName()

getBlockSize

public int getBlockSize()

processBlock

public int processBlock(byte[] in,
                        int inOff,
                        byte[] out,
                        int outOff)

reset

public void reset()