Class SM4Engine

  • All Implemented Interfaces:
    BlockCipher

    public class SM4Engine
    extends java.lang.Object
    implements BlockCipher
    SM4 Block Cipher - SM4 is a 128 bit block cipher with a 128 bit key.

    The implementation here is based on the document http://eprint.iacr.org/2008/329.pdf by Whitfield Diffie and George Ledin, which is a translation of Prof. LU Shu-wang's original standard.

    • Constructor Summary

      Constructors 
      Constructor Description
      SM4Engine()  
    • 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 the 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

      • SM4Engine

        public SM4Engine()
    • Method Detail

      • init

        public void init​(boolean forEncryption,
                         CipherParameters params)
                  throws java.lang.IllegalArgumentException
        Description copied from interface: BlockCipher
        Initialise the cipher.
        Specified by:
        init in interface BlockCipher
        Parameters:
        forEncryption - if true the cipher is initialised for encryption, if false for decryption.
        params - the key and other data required by 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)
                         throws DataLengthException,
                                java.lang.IllegalStateException
        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.
        Throws:
        DataLengthException - if there isn't enough data in in, or space in out.
        java.lang.IllegalStateException - if the cipher isn't initialised.
      • 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