public class AES extends java.lang.Object implements BlockCipher
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
Modifier and Type | Field and Description |
---|---|
private static int |
BLOCK_SIZE |
private int |
C0 |
private int |
C1 |
private int |
C2 |
private int |
C3 |
private boolean |
doEncrypt |
private static int |
m1 |
private static int |
m2 |
private static int |
m3 |
private static int[] |
rcon |
private int |
ROUNDS |
private static byte[] |
S |
private static byte[] |
Si |
private static int[] |
T0 |
private static int[] |
T1 |
private static int[] |
T2 |
private static int[] |
T3 |
private static int[] |
Tinv0 |
private static int[] |
Tinv1 |
private static int[] |
Tinv2 |
private static int[] |
Tinv3 |
private int[][] |
WorkingKey |
Constructor and Description |
---|
AES()
default constructor - 128 bit block size.
|
Modifier and Type | Method and Description |
---|---|
private void |
decryptBlock(int[][] KW) |
private void |
encryptBlock(int[][] KW) |
private int |
FFmulX(int x) |
private int[][] |
generateWorkingKey(byte[] key,
boolean forEncryption)
Calculate the necessary round keys The number of calculations depends on
key size and block size AES specified a fixed block size of 128 bits and
key sizes 128/192/256 bits This code is written assuming those are the
only possible values
|
java.lang.String |
getAlgorithmName() |
int |
getBlockSize() |
void |
init(boolean forEncryption,
byte[] key)
initialise an AES cipher.
|
private int |
inv_mcol(int x) |
private void |
packBlock(byte[] bytes,
int off) |
int |
processBlock(byte[] in,
int inOff,
byte[] out,
int outOff) |
void |
reset() |
private int |
shift(int r,
int shift) |
private int |
subWord(int x) |
void |
transformBlock(byte[] src,
int srcoff,
byte[] dst,
int dstoff) |
private void |
unpackBlock(byte[] bytes,
int off) |
private static final byte[] S
private static final byte[] Si
private static final int[] rcon
private static final int[] T0
private static final int[] T1
private static final int[] T2
private static final int[] T3
private static final int[] Tinv0
private static final int[] Tinv1
private static final int[] Tinv2
private static final int[] Tinv3
private static final int m1
private static final int m2
private static final int m3
private int ROUNDS
private int[][] WorkingKey
private int C0
private int C1
private int C2
private int C3
private boolean doEncrypt
private static final int BLOCK_SIZE
private final int shift(int r, int shift)
private final int FFmulX(int x)
private final int inv_mcol(int x)
private final int subWord(int x)
private final int[][] generateWorkingKey(byte[] key, boolean forEncryption)
public final void init(boolean forEncryption, byte[] key)
init
in interface BlockCipher
forEncryption
- whether or not we are for encryption.key
- the key required to set up the cipher.java.lang.IllegalArgumentException
- if the params argument is inappropriate.public final java.lang.String getAlgorithmName()
public final int getBlockSize()
getBlockSize
in interface BlockCipher
public final int processBlock(byte[] in, int inOff, byte[] out, int outOff)
public final void reset()
private final void unpackBlock(byte[] bytes, int off)
private final void packBlock(byte[] bytes, int off)
private final void encryptBlock(int[][] KW)
private final void decryptBlock(int[][] KW)
public void transformBlock(byte[] src, int srcoff, byte[] dst, int dstoff)
transformBlock
in interface BlockCipher