Class AESFastEngine

java.lang.Object
org.gudy.bouncycastle.crypto.engines.AESFastEngine
All Implemented Interfaces:
BlockCipher

public class AESFastEngine extends 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

  • Field Summary

    Fields
    Modifier and Type
    Field
    Description
    private 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[][]
     
  • Constructor Summary

    Constructors
    Constructor
    Description
    default constructor - 128 bit block size.
  • Method Summary

    Modifier and Type
    Method
    Description
    private 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 values
    Return 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 the cipher.
    private static int
    shift(int r, int shift)
     
    private static int
    subWord(int x)
     
    private void
    unpackBlock(byte[] bytes, int off)
     

    Methods inherited from class java.lang.Object

    clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
  • Field Details

    • 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:
    • m2

      private static final int m2
      See Also:
    • m3

      private static final int m3
      See Also:
    • 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:
  • Constructor Details

    • AESFastEngine

      public AESFastEngine()
      default constructor - 128 bit block size.
  • Method Details

    • 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

      public void init(boolean forEncryption, CipherParameters params)
      initialise an AES cipher.
      Specified by:
      init in interface BlockCipher
      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()
      Description copied from interface: BlockCipher
      Return the name of the algorithm the cipher implements.
      Specified by:
      getAlgorithmName in interface BlockCipher
      Returns:
      the name of the algorithm the cipher implements.
    • getBlockSize

      public int getBlockSize()
      Description copied from interface: BlockCipher
      Return the block size for this cipher (in bytes).
      Specified by:
      getBlockSize in interface BlockCipher
      Returns:
      the block size for this cipher in bytes.
    • 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 interface BlockCipher
      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.
    • 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 interface BlockCipher
    • 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)