org.bouncycastle.crypto.engines
Class AESFastEngine
java.lang.Object
org.bouncycastle.crypto.engines.AESFastEngine
- BlockCipher
public class AESFastEngine
extends java.lang.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
String | getAlgorithmName() - Return the name of the algorithm the cipher implements.
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int | getBlockSize() - Return the block size for this cipher (in bytes).
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void | init(boolean forEncryption, CipherParameters params) - initialise an AES cipher.
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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.
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void | reset() - Reset the cipher.
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AESFastEngine
public AESFastEngine()
default constructor - 128 bit block size.
getAlgorithmName
public String getAlgorithmName()
Return the name of the algorithm the cipher implements.
- getAlgorithmName in interface BlockCipher
- the name of the algorithm the cipher implements.
getBlockSize
public int getBlockSize()
Return the block size for this cipher (in bytes).
- getBlockSize in interface BlockCipher
- the block size for this cipher in bytes.
init
public void init(boolean forEncryption,
CipherParameters params)
initialise an AES cipher.
- init in interface BlockCipher
forEncryption
- whether or not we are for encryption.params
- the parameters required to set up the cipher.
processBlock
public 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.
- processBlock in interface BlockCipher
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.
- the number of bytes processed and produced.
reset
public void reset()
Reset the cipher. After resetting the cipher is in the same state
as it was after the last init (if there was one).
- reset in interface BlockCipher