Class AESFastEngine
- All Implemented Interfaces:
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
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Field Summary
FieldsModifier and TypeFieldDescriptionprivate static final int
private int
private int
private int
private int
private boolean
private static final int
private static final int
private static final int
private static final int[]
private int
private static final byte[]
private static final byte[]
private static final int[]
private static final int[]
private static final int[]
private static final int[]
private static final int[]
private static final int[]
private static final int[]
private static final int[]
private int[][]
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Constructor Summary
Constructors -
Method Summary
Modifier and TypeMethodDescriptionprivate void
decryptBlock
(int[][] KW) private void
encryptBlock
(int[][] KW) private static 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 valuesReturn the name of the algorithm the cipher implements.int
Return the block size for this cipher (in bytes).void
init
(boolean forEncryption, CipherParameters params) initialise an AES cipher.private static int
inv_mcol
(int x) private void
packBlock
(byte[] bytes, int off) int
processBlock
(byte[] in, int inOff, byte[] out, int outOff) Process one block of input from the array in and write it to the out array.void
reset()
Reset the cipher.private static int
shift
(int r, int shift) private static int
subWord
(int x) private void
unpackBlock
(byte[] bytes, int off)
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Field Details
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S
private static final byte[] S -
Si
private static final byte[] Si -
rcon
private static final int[] rcon -
T0
private static final int[] T0 -
T1
private static final int[] T1 -
T2
private static final int[] T2 -
T3
private static final int[] T3 -
Tinv0
private static final int[] Tinv0 -
Tinv1
private static final int[] Tinv1 -
Tinv2
private static final int[] Tinv2 -
Tinv3
private static final int[] Tinv3 -
m1
private static final int m1- See Also:
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m2
private static final int m2- See Also:
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m3
private static final int m3- See Also:
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ROUNDS
private int ROUNDS -
WorkingKey
private int[][] WorkingKey -
C0
private int C0 -
C1
private int C1 -
C2
private int C2 -
C3
private int C3 -
forEncryption
private boolean forEncryption -
BLOCK_SIZE
private static final int BLOCK_SIZE- See Also:
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Constructor Details
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AESFastEngine
public AESFastEngine()default constructor - 128 bit block size.
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Method Details
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shift
private static int shift(int r, int shift) -
FFmulX
private static int FFmulX(int x) -
inv_mcol
private static int inv_mcol(int x) -
subWord
private static int subWord(int x) -
generateWorkingKey
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 -
init
initialise an AES cipher.- Specified by:
init
in interfaceBlockCipher
- 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.
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getAlgorithmName
Description copied from interface:BlockCipher
Return the name of the algorithm the cipher implements.- Specified by:
getAlgorithmName
in interfaceBlockCipher
- Returns:
- the name of the algorithm the cipher implements.
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getBlockSize
public int getBlockSize()Description copied from interface:BlockCipher
Return the block size for this cipher (in bytes).- Specified by:
getBlockSize
in interfaceBlockCipher
- Returns:
- the block size for this cipher in bytes.
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processBlock
public int processBlock(byte[] in, int inOff, byte[] out, int outOff) Description copied from interface:BlockCipher
Process one block of input from the array in and write it to the out array.- Specified by:
processBlock
in interfaceBlockCipher
- Parameters:
in
- the array containing the input data.inOff
- offset into the in array the data starts at.out
- the array the output data will be copied into.outOff
- the offset into the out array the output will start at.- Returns:
- the number of bytes processed and produced.
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reset
public void reset()Description copied from interface:BlockCipher
Reset the cipher. After resetting the cipher is in the same state as it was after the last init (if there was one).- Specified by:
reset
in interfaceBlockCipher
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unpackBlock
private void unpackBlock(byte[] bytes, int off) -
packBlock
private void packBlock(byte[] bytes, int off) -
encryptBlock
private void encryptBlock(int[][] KW) -
decryptBlock
private void decryptBlock(int[][] KW)
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