Class AESLightEngine

  • All Implemented Interfaces:
    BlockCipher

    public class AESLightEngine
    extends java.lang.Object
    implements BlockCipher
    an implementation of the AES (Rijndael), from FIPS-197.

    For further details see: https://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 slowest performance version with no static tables for round precomputation, but it has the smallest foot print.

    • Constructor Summary

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

      All Methods Instance Methods Concrete Methods 
      Modifier and Type Method Description
      java.lang.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

        clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
    • Constructor Detail

      • AESLightEngine

        public AESLightEngine()
        default constructor - 128 bit block size.
    • Method Detail

      • 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:
        java.lang.IllegalArgumentException - if the params argument is inappropriate.
      • getAlgorithmName

        public java.lang.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