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cryptix.jce.provider.key
Class DESKeyGenerator  

java.lang.Object
  javax.crypto.KeyGeneratorSpi
      cryptix.jce.provider.key.RawKeyGenerator
          cryptix.jce.provider.key.DESKeyGenerator

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public class DESKeyGenerator

extends RawKeyGenerator

A key generator for DES.

Version:

$Revision: 1.7 $

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Constructor Summary

DESKeyGenerator()

 

Method Summary
protected  javax.crypto.SecretKey	engineGenerateKey()           Generate a key, returning it as a javax.crypto.SecretKey.
protected  void	engineInit(java.security.spec.AlgorithmParameterSpec params, java.security.SecureRandom random)           Initialize this key generator with parameters and a source of randomness.
protected  void	engineInit(int keysize, java.security.SecureRandom random)           Initialize this key generator with a key size (in bits) and a source of randomness.
protected  void	engineInit(java.security.SecureRandom random)           Initialize this key generator with a source of randomness; the implementation should use reasonable default parameters (such as generated key size).
protected  byte[]	fixUp(byte[] key)           Fix the parity
protected  boolean	isValidSize(int size)           Is the given keysize valid for this algorithm?
protected  boolean	isWeak(byte[] key)           Test for weak keys
private  boolean	isWeak(byte[] key, int offset)           Returns true iff the bytes at key[offset..offset+7] represent a weak or semi-weak single DES key.
protected  int	strengthToBits(int strength)           Translates strength (complexity, 56 for DES) to bit length (64 for DES).

 

Methods inherited from class java.lang.Object

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

 

Constructor Detail

DESKeyGenerator

public DESKeyGenerator()

Method Detail

isWeak

protected boolean isWeak(byte[] key)

Test for weak keys

Specified by:

isWeak in class RawKeyGenerator

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isWeak

private boolean isWeak(byte[] key,
                       int offset)

Returns true iff the bytes at key[offset..offset+7] represent a weak or semi-weak single DES key. It can be called either before or after setting parity bits.

(This checks for the 16 weak and semi-weak keys as given by Schneier, Applied Cryptography 2nd ed., tables 12.11 and 12.12. It does not check for the possibly-weak keys in table 12.13.)

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isValidSize

protected boolean isValidSize(int size)

Description copied from class: RawKeyGenerator

Is the given keysize valid for this algorithm?

Specified by:

isValidSize in class RawKeyGenerator

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strengthToBits

protected int strengthToBits(int strength)

Description copied from class: RawKeyGenerator

Translates strength (complexity, 56 for DES) to bit length (64 for DES).

Overrides:

strengthToBits in class RawKeyGenerator

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fixUp

protected byte[] fixUp(byte[] key)

Fix the parity

Overrides:

fixUp in class RawKeyGenerator

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engineInit

protected void engineInit(java.security.SecureRandom random)

Description copied from class: javax.crypto.KeyGeneratorSpi

Initialize this key generator with a source of randomness; the implementation should use reasonable default parameters (such as generated key size).

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engineInit

protected void engineInit(java.security.spec.AlgorithmParameterSpec params,
                          java.security.SecureRandom random)
                   throws java.security.InvalidAlgorithmParameterException

Description copied from class: javax.crypto.KeyGeneratorSpi

Initialize this key generator with parameters and a source of randomness.

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engineInit

protected void engineInit(int keysize,
                          java.security.SecureRandom random)

Description copied from class: javax.crypto.KeyGeneratorSpi

Initialize this key generator with a key size (in bits) and a source of randomness.

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engineGenerateKey

protected javax.crypto.SecretKey engineGenerateKey()

Description copied from class: javax.crypto.KeyGeneratorSpi

Generate a key, returning it as a javax.crypto.SecretKey.

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Home >> All >> cryptix >> jce >> provider >> [ key overview ]	PREV CLASS  NEXT CLASS
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