Class AES
- java.lang.Object
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- com.trilead.ssh2.crypto.cipher.AES
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- All Implemented Interfaces:
BlockCipher
public class AES extends java.lang.Object implements BlockCipher
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
- Version:
- $Id: AES.java,v 1.1 2007/10/15 12:49:55 cplattne Exp $
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Field Summary
Fields Modifier and Type Field 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
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Constructor Summary
Constructors Constructor Description AES()
default constructor - 128 bit block size.
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Method Summary
All Methods Instance Methods Concrete Methods Modifier and Type Method 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 valuesjava.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)
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Field Detail
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S
private static final byte[] S
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Si
private static final byte[] Si
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rcon
private static final int[] rcon
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T0
private static final int[] T0
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T1
private static final int[] T1
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T2
private static final int[] T2
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T3
private static final int[] T3
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Tinv0
private static final int[] Tinv0
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Tinv1
private static final int[] Tinv1
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Tinv2
private static final int[] Tinv2
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Tinv3
private static final int[] Tinv3
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m1
private static final int m1
- See Also:
- Constant Field Values
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m2
private static final int m2
- See Also:
- Constant Field Values
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m3
private static final int m3
- See Also:
- Constant Field Values
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ROUNDS
private int ROUNDS
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WorkingKey
private int[][] WorkingKey
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C0
private int C0
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C1
private int C1
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C2
private int C2
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C3
private int C3
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doEncrypt
private boolean doEncrypt
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BLOCK_SIZE
private static final int BLOCK_SIZE
- See Also:
- Constant Field Values
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Method Detail
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shift
private final int shift(int r, int shift)
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FFmulX
private final int FFmulX(int x)
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inv_mcol
private final int inv_mcol(int x)
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subWord
private final int subWord(int x)
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generateWorkingKey
private final 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
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init
public final void init(boolean forEncryption, byte[] key)
initialise an AES cipher.- Specified by:
init
in interfaceBlockCipher
- Parameters:
forEncryption
- whether or not we are for encryption.key
- the key required to set up the cipher.- Throws:
java.lang.IllegalArgumentException
- if the params argument is inappropriate.
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getAlgorithmName
public final java.lang.String getAlgorithmName()
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getBlockSize
public final int getBlockSize()
- Specified by:
getBlockSize
in interfaceBlockCipher
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processBlock
public final int processBlock(byte[] in, int inOff, byte[] out, int outOff)
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reset
public final void reset()
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unpackBlock
private final void unpackBlock(byte[] bytes, int off)
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packBlock
private final void packBlock(byte[] bytes, int off)
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encryptBlock
private final void encryptBlock(int[][] KW)
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decryptBlock
private final void decryptBlock(int[][] KW)
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transformBlock
public void transformBlock(byte[] src, int srcoff, byte[] dst, int dstoff)
- Specified by:
transformBlock
in interfaceBlockCipher
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