net.vattp.data
Class DES

java.lang.Object
  |
  +--net.vattp.data.DES

public final class DES

extends Object

Untamed:

Field Summary

private static int	BLOCK_SIZE
private static boolean	DEBUG
private static int	debuglevel
private static int	DECRYPT
private static int	ENCRYPT
private int	encryptDecryptState State for encrypt/decrypt/uninitialized.
private static String	HEXSTR
private static int	INTERNAL_KEY_LENGTH
private static int	KEY_LENGTH
private static int	ROUNDS
private static int[]	SKB Table for PC2 permutations in key schedule computation.
private int[]	sKey The internal key schedule.
private static int[]	SP_TRANS Table for S-boxes and permutations, used in encrypt_base.
private static String[][]	tests
private static int	UNINITIALIZED

Constructor Summary

DES()
Enabled: Constructs a DES cipher object, in the UNINITIALIZED state.

Method Summary

private static boolean	areEqual(byte[] a, byte[] b)
int	blockSize() Enabled: SPI: Returns the length of an input block, in bytes.
Object	clone() Suppressed: Always throws a CloneNotSupportedException (cloning of ciphers is not supported for security reasons).
byte[]	crypt(byte[] data) Enabled:
private void	decrypt_base(int[] io) Implements DES decryption without IP and FP.
private void	des(byte[] in, int inOffset, byte[] out, int outOffset, boolean encrypt) Encrypts/decrypts a block, of length BLOCK_SIZE.
private void	encrypt_base(int[] io) Implements DES encryption without IP and FP.
private static void	finalPermutation(int[] io)
private static String	getAlgorithm()
private static byte[]	hexFromString(String s)
void	initDecrypt(byte[] key) Enabled: SPI: Initializes this cipher for decryption, using the specified key.
void	initEncrypt(byte[] key) Enabled: SPI: Initializes this cipher for encryption, using the specified key.
private static void	initialPermutation(int[] io)
static void	main(String[] argv) Enabled: Entry point for self_test.
private void	makeKey(byte[] userkey) Expands a user-key to a working key schedule.
private static void	self_test()
int	update(byte[] in, int inOffset, int inLen, byte[] out, int outOffset) Enabled: SPI: This is the main method for updating data.

Methods inherited from class java.lang.Object

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

Field Detail

DEBUG

private static final boolean DEBUG

debuglevel

private static final int debuglevel

ROUNDS

private static final int ROUNDS

BLOCK_SIZE

private static final int BLOCK_SIZE

KEY_LENGTH

private static final int KEY_LENGTH

INTERNAL_KEY_LENGTH

private static final int INTERNAL_KEY_LENGTH

encryptDecryptState

private int encryptDecryptState

State for encrypt/decrypt/uninitialized.

UNINITIALIZED

private static final int UNINITIALIZED

ENCRYPT

private static final int ENCRYPT

DECRYPT

private static final int DECRYPT

SKB

private static final int[] SKB

Table for PC2 permutations in key schedule computation.

sKey

private final int[] sKey

The internal key schedule.

SP_TRANS

private static final int[] SP_TRANS

Table for S-boxes and permutations, used in encrypt_base.

tests

private static final String[][] tests

HEXSTR

private static final String HEXSTR

Constructor Detail

DES

public DES()

Enabled: Constructs a DES cipher object, in the UNINITIALIZED state.

Method Detail

clone

public final Object clone()
                   throws CloneNotSupportedException

Suppressed: Always throws a CloneNotSupportedException (cloning of ciphers is not supported for security reasons).

Overrides:

clone in class Object

Returns:

a clone of this instance.

CloneNotSupportedException

See Also:

java.lang.Cloneable

blockSize

public int blockSize()

Enabled: SPI: Returns the length of an input block, in bytes.

Returns:

the length in bytes of an input block for this cipher.

initEncrypt

public void initEncrypt(byte[] key)
                 throws InvalidKeyException

Enabled: SPI: Initializes this cipher for encryption, using the specified key.

Parameters:

key - the key to use for encryption.

Throws:

InvalidKeyException - if one of the following occurs:

• key.getEncoded() == null;
• The length of the user key array is not KEY_LENGTH.

initDecrypt

public void initDecrypt(byte[] key)
                 throws InvalidKeyException

Enabled: SPI: Initializes this cipher for decryption, using the specified key.

Parameters:

key - the key to use for decryption.

Throws:

InvalidKeyException - if one of the following occurs:

• key.getEncoded() == null;
• The length of the user key array is not KEY_LENGTH.

crypt

public byte[] crypt(byte[] data)

Enabled:

update

public int update(byte[] in,
                  int inOffset,
                  int inLen,
                  byte[] out,
                  int outOffset)

Enabled: SPI: This is the main method for updating data.

in and out may be the same array, and the input and output regions may overlap.

Parameters:

in - the input data.

inOffset - the offset into in specifying where the data starts.

inLen - the length of the subarray.

out - the output array.

outOffset - the offset indicating where to start writing into the out array.

Returns:

the number of bytes written.

makeKey

private void makeKey(byte[] userkey)
              throws InvalidKeyException

Expands a user-key to a working key schedule.

Parameters:

userkey - the user-key object to use.

Throws:

InvalidKeyException - if one of the following occurs:

• key.getEncoded() == null;
• The length of the user key array is not KEY_LENGTH.

des

private void des(byte[] in,
                 int inOffset,
                 byte[] out,
                 int outOffset,
                 boolean encrypt)

Encrypts/decrypts a block, of length BLOCK_SIZE.

Parameters:

in - an array containing the input block

inOffset - the starting offset of the input block

out - an array containing the output block

encrypt - true to encrypt, false to decrypt

encrypt_base

private void encrypt_base(int[] io)

Implements DES encryption without IP and FP.

decrypt_base

private void decrypt_base(int[] io)

Implements DES decryption without IP and FP.

initialPermutation

private static void initialPermutation(int[] io)

finalPermutation

private static void finalPermutation(int[] io)

getAlgorithm

private static String getAlgorithm()

main

public static void main(String[] argv)

Enabled: Entry point for self_test.

self_test

private static void self_test()
                       throws Exception

Exception

areEqual

private static boolean areEqual(byte[] a,
                                byte[] b)

hexFromString

private static byte[] hexFromString(String s)