Package org.bouncycastle.crypto.engines

Class AESEngine

java.lang.Object
org.bouncycastle.crypto.engines.AESEngine
All Implemented Interfaces:
BlockCipher
public class AESEngine 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 middle performance version with 2Kbytes of static tables for round precomputation.

  • Constructor Summary

    Constructors
    Constructor
    Description
    AESEngine()
    default constructor - 128 bit block size.

  • Method Summary

    Modifier and Type
    Method
    Description
    String
    getAlgorithmName()
    Return the name of the algorithm the cipher implements.
    int
    getBlockSize()
    Return the block size for this cipher (in bytes).
    void
    init(boolean forEncryption, CipherParameters params)
    initialise an AES cipher.
    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.

    Methods inherited from class java.lang.Object

    equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

  • Constructor Details

    • AESEngine

      public AESEngine()
      default constructor - 128 bit block size.

  • Method Details

    • 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