Bouncy Castle Cryptography Library 1.37

org.bouncycastle.crypto.engines
Class CAST5Engine

java.lang.Object
  extended by org.bouncycastle.crypto.engines.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
protected  int[] _Km
           
protected  int[] _Kr
           
protected static int BLOCK_SIZE
           
protected static int M32
           
protected static int MAX_ROUNDS
           
protected static int RED_ROUNDS
           
protected static int[] S1
           
protected static int[] S2
           
protected static int[] S3
           
protected static int[] S4
           
protected static int[] S5
           
protected static int[] S6
           
protected static int[] S7
           
protected static int[] S8
           
 
Constructor Summary
CAST5Engine()
           
 
Method Summary
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
 

Field Detail

M32

protected static final int M32
See Also:
Constant Field Values

S1

protected static final int[] S1

S2

protected static final int[] S2

S3

protected static final int[] S3

S4

protected static final int[] S4

S5

protected static final int[] S5

S6

protected static final int[] S6

S7

protected static final int[] S7

S8

protected static final int[] S8

MAX_ROUNDS

protected static final int MAX_ROUNDS
See Also:
Constant Field Values

RED_ROUNDS

protected static final int RED_ROUNDS
See Also:
Constant Field Values

BLOCK_SIZE

protected static final int BLOCK_SIZE
See Also:
Constant Field Values

_Kr

protected int[] _Kr

_Km

protected int[] _Km
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)

Bouncy Castle Cryptography Library 1.37