net.vattp.data
Class TripleDESKeyConstructor

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

final class TripleDESKeyConstructor

extends Object

Utility method for constructing a 3DES key from a Diffie-Hellman secret.

Author:

This file contains only code created by Tyler Close, not a citizen or resident of the US.

Field Summary

private static int	DES_KEY_LENGTH
private static String	DIGEST_ALGORITHM_NAME
private static int	KEY_PAD_LENGTH
private static int	TRIPLE_DES_KEY_LENGTH

Constructor Summary

(package private)

TripleDESKeyConstructor()

Method Summary

private static void	fill(byte[] buffer, byte value)
(package private) static byte[]	make(byte[] dhSecret) Constructs a 3DES key from a Diffie-Hellman secret.

Methods inherited from class java.lang.Object

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

Field Detail

DIGEST_ALGORITHM_NAME

private static final String DIGEST_ALGORITHM_NAME

DES_KEY_LENGTH

private static final int DES_KEY_LENGTH

TRIPLE_DES_KEY_LENGTH

private static final int TRIPLE_DES_KEY_LENGTH

KEY_PAD_LENGTH

private static final int KEY_PAD_LENGTH

Constructor Detail

TripleDESKeyConstructor

TripleDESKeyConstructor()

Method Detail

make

static byte[] make(byte[] dhSecret)

Constructs a 3DES key from a Diffie-Hellman secret. The individual keys are calculated from a Diffie-Hellman secret using MD5 and a 16 byte pad consisting of a single byte repeated 16 times as follows: 3DESKey1 is the first 8 bytes of md5((16,pad)(n,dhSecret)) with 0x55 for the pad. 3DESKey2 is the second 8 bytes of md5((16,pad)(n,dhSecret)) with 0x55 for the pad. 3DESKey3 is the first 8 bytes of md5((16,pad)(n,dhSecret)) with 0xaa for the pad.

Parameters:

dhSecret - the Diffie-Hellman secret

Returns:

a byte[] containing the constructed key.

See Also:

cryptix.provider.key.RawKey,

fill

private static void fill(byte[] buffer,
                         byte value)