iaik.security.cipher
Class TripleDESKeyGenerator

java.lang.Object
  |
  +--javax.crypto.KeyGeneratorSpi
        |
        +--iaik.security.cipher.VarLengthKeyGenerator
              |
              +--iaik.security.cipher.TripleDESKeyGenerator

public class TripleDESKeyGenerator

extends iaik.security.cipher.VarLengthKeyGenerator

This class provides the functionality of a TripleDES key generator. A key generator is used for creating secret keys for symmetric algorithms.

An application uses

 KeyGenerator key_gen = KeyGenerator.getInstance("TripleDES");
 

for creating a KeyGenerator object for the TripleDES algorithm. For actually generating the requested secret TripleDES key from the KeyGenerator object just created, an application calls the generateKey method after having initialized the generator with some random seed or relied on the default system-provided source of randomness:

 SecretKey triple_des_key = key_gen.generateKey();
 

A TripleDES key is composed of three DES keys. For extracting the inherent DES keys, an application may use the getEncoded method to get a byte array representation of the TripleDES key and subsequently split it accordingly:

  des key1 = first 8 bytes of key
  des key2 = second 8 bytes of key
  des key3 = first 8 bytes of key in case of 2 key triple DES, third 8 bytes otherwise
 

Version:

File Revision 18

See Also:

KeyGenerator, KeyGeneratorSpi, SecretKey, SecretKey, DESKeyGenerator, TripleDES

Constructor Summary

TripleDESKeyGenerator()

Method Summary

protected SecretKey	engineGenerateKey() Generates a new key.
protected void	engineInit(AlgorithmParameterSpec params, SecureRandom random) Initializes this key generator.
protected void	engineInit(int strength, SecureRandom random) Initializes this key generator for the given strength with the given random seed.
protected void	engineInit(SecureRandom random) Initializes this key generator with the given random seed.

Methods inherited from class java.lang.Object

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

Constructor Detail

TripleDESKeyGenerator

public TripleDESKeyGenerator()

Method Detail

engineInit

protected void engineInit(int strength,
                          SecureRandom random)

Description copied from class: iaik.security.cipher.VarLengthKeyGenerator

Initializes this key generator for the given strength with the given random seed. Lengths outside the range of minimum to maximum length default to the default length.

Overrides:

engineInit in class iaik.security.cipher.VarLengthKeyGenerator

Following copied from class: iaik.security.cipher.VarLengthKeyGenerator

Parameters:

strength - the strength of the key to be created

random - the random seed

engineGenerateKey

protected SecretKey engineGenerateKey()

Description copied from class: iaik.security.cipher.VarLengthKeyGenerator

Generates a new key.

Overrides:

engineGenerateKey in class iaik.security.cipher.VarLengthKeyGenerator

Following copied from class: iaik.security.cipher.VarLengthKeyGenerator

Returns:

the created key

See Also:

SecretKey

engineInit

protected void engineInit(AlgorithmParameterSpec params,
                          SecureRandom random)
                   throws InvalidAlgorithmParameterException

Initializes this key generator. If params is not null, otherwise this call is identical to engineInit(random).

Overrides:

engineInit in class KeyGeneratorSpi

Throws:

InvalidAlgorithmParameterException - if parameters are passed

engineInit

protected void engineInit(SecureRandom random)

Initializes this key generator with the given random seed. The strength defaults to the default length.

Overrides:

engineInit in class KeyGeneratorSpi

Parameters:

random - the random seed for this generator