Package org.bouncycastle.crypto.engines

Class CAST5Engine

  • All Implemented Interfaces:
    BlockCipher
    Direct Known Subclasses:
    CAST6Engine
    public class CAST5Engine
extends java.lang.Object
implements BlockCipher
    A class that provides CAST key encryption operations, such as encoding data and generating keys. All the algorithms herein are from the Internet RFC's RFC2144 - CAST5 (64bit block, 40-128bit key) RFC2612 - CAST6 (128bit block, 128-256bit key) and implement a simplified cryptography interface.

    • Field Summary

      Fields 
      Modifier and Type Field Description
      protected int[] _Km  
      protected int[] _Kr  
      protected static int BLOCK_SIZE  
      protected static int MAX_ROUNDS  
      protected static int RED_ROUNDS  

    • Constructor Summary

      Constructors 
      Constructor Description
      CAST5Engine()  

    • Method Summary

      All Methods Instance Methods Concrete Methods 
      Modifier and Type Method Description
      protected void Bits32ToBytes​(int in, byte[] b, int offset)  
      protected void Bits32ToInts​(int in, int[] b, int offset)  
      protected int BytesTo32bits​(byte[] b, int i)  
      protected void CAST_Decipher​(int L16, int R16, int[] result)  
      protected void CAST_Encipher​(int L0, int R0, int[] result)
      Does the 16 rounds to encrypt the block.
      protected int decryptBlock​(byte[] src, int srcIndex, byte[] dst, int dstIndex)
      Decrypt the given input starting at the given offset and place the result in the provided buffer starting at the given offset.
      protected int encryptBlock​(byte[] src, int srcIndex, byte[] dst, int dstIndex)
      Encrypt the given input starting at the given offset and place the result in the provided buffer starting at the given offset.
      protected int F1​(int D, int Kmi, int Kri)
      The first of the three processing functions for the encryption and decryption.
      protected int F2​(int D, int Kmi, int Kri)
      The second of the three processing functions for the encryption and decryption.
      protected int F3​(int D, int Kmi, int Kri)
      The third of the three processing functions for the encryption and decryption.
      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 encrypting, CipherParameters params)
      initialise a CAST cipher.
      protected int IntsTo32bits​(int[] b, int i)  
      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.
      protected void setKey​(byte[] key)  

      • Methods inherited from class java.lang.Object

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

    • Constructor Detail

      • CAST5Engine

        public CAST5Engine()

    • Method Detail

      • init

        public void init​(boolean encrypting,
                 CipherParameters params)
        initialise a CAST cipher.
        Specified by:
        init in interface BlockCipher
        Parameters:
        encrypting - 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.

      • 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

      • 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.

      • setKey

        protected void setKey​(byte[] key)

      • encryptBlock

        protected int encryptBlock​(byte[] src,
                           int srcIndex,
                           byte[] dst,
                           int dstIndex)
        Encrypt the given input starting at the given offset and place the result in the provided buffer starting at the given offset.
        Parameters:
        src - The plaintext buffer
        srcIndex - An offset into src
        dst - The ciphertext buffer
        dstIndex - An offset into dst

      • decryptBlock

        protected int decryptBlock​(byte[] src,
                           int srcIndex,
                           byte[] dst,
                           int dstIndex)
        Decrypt the given input starting at the given offset and place the result in the provided buffer starting at the given offset.
        Parameters:
        src - The plaintext buffer
        srcIndex - An offset into src
        dst - The ciphertext buffer
        dstIndex - An offset into dst

      • F1

        protected final int F1​(int D,
                       int Kmi,
                       int Kri)
        The first of the three processing functions for the encryption and decryption.
        Parameters:
        D - the input to be processed
        Kmi - the mask to be used from Km[n]
        Kri - the rotation value to be used

      • F2

        protected final int F2​(int D,
                       int Kmi,
                       int Kri)
        The second of the three processing functions for the encryption and decryption.
        Parameters:
        D - the input to be processed
        Kmi - the mask to be used from Km[n]
        Kri - the rotation value to be used

      • F3

        protected final int F3​(int D,
                       int Kmi,
                       int Kri)
        The third of the three processing functions for the encryption and decryption.
        Parameters:
        D - the input to be processed
        Kmi - the mask to be used from Km[n]
        Kri - the rotation value to be used

      • CAST_Encipher

        protected final void CAST_Encipher​(int L0,
                                   int R0,
                                   int[] result)
        Does the 16 rounds to encrypt the block.
        Parameters:
        L0 - the LH-32bits of the plaintext block
        R0 - the RH-32bits of the plaintext block

      • CAST_Decipher

        protected final void CAST_Decipher​(int L16,
                                   int R16,
                                   int[] result)

      • Bits32ToInts

        protected final void Bits32ToInts​(int in,
                                  int[] b,
                                  int offset)

      • IntsTo32bits

        protected final int IntsTo32bits​(int[] b,
                                 int i)

      • Bits32ToBytes

        protected final void Bits32ToBytes​(int in,
                                   byte[] b,
                                   int offset)

      • BytesTo32bits

        protected final int BytesTo32bits​(byte[] b,
                                  int i)