iaik.security.cipher

Class TripleDESKeyGenerator

java.lang.Object

javax.crypto.KeyGeneratorSpi

iaik.security.cipher.TripleDESKeyGenerator

public class TripleDESKeyGenerator
extends javax.crypto.KeyGeneratorSpi

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
 

This class SHOULD NOT be used directly; it should only be used through the JCA/JCE.

FIPS 140-2:

This class is part of the Toolkit's FIPS 140-2 cryptographic module and contains APIs that are considered part of the logical interface to the Toolkit's FIPS 140-2 cryptographic module; refer to the API documentation for further details

See Also:

KeyGenerator, KeyGeneratorSpi, SecretKey, SecretKey, DESKeyGenerator, TripleDES

Constructor Summary

Constructors

Constructor and Description
TripleDESKeyGenerator() The constructor; creates a new instance of the DESede key generation algorithm.

Method Summary

Modifier and Type	Method and Description
protected javax.crypto.SecretKey	engineGenerateKey() Generates a secret key.
protected void	engineInit(java.security.spec.AlgorithmParameterSpec params, java.security.SecureRandom random) Initializes the key generator with the specified parameter set and a user-provided source of randomness.
protected void	engineInit(int strength, java.security.SecureRandom random) Initializes this key generator for a certain keysize, using the given source of randomness.
protected void	engineInit(java.security.SecureRandom random) Initializes the key generator.

Methods inherited from class java.lang.Object

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

Constructor Detail

TripleDESKeyGenerator

public TripleDESKeyGenerator()

The constructor; creates a new instance of the DESede key generation algorithm.

Applications should not use this constructor, instead the key generation algorithm should be requested from the appropriate JCA/JCE cryptographic service provider as follows: KeyGenerator.getInstance("DESede", "IAIK").

FIPS 140-2:

FIPS Service: Modify Object

This API is part of the logical interface to the Toolkit's FIPS 140-2 cryptographic module; use of this API causes the caller to assume the FIPS 140-2 user role and accesses the following FIPS 140-2 logical interfaces:

• control input interface (API call)
• status output interface (exceptions)

Method Detail

engineInit

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

Initializes this key generator for a certain keysize, using the given source of randomness.

Lengths outside the range of minimum to maximum length default to the default length.

FIPS 140-2:

FIPS Service: Initialization

This API is part of the logical interface to the Toolkit's FIPS 140-2 cryptographic module; use of this API causes the caller to assume the FIPS 140-2 user role and accesses the following FIPS 140-2 logical interfaces:

• control input interface (API call, parameters)
• data input interface (parameters)
• status output interface (exceptions)

Parameters:

strength - [FIPS 140-2 data input] the keysize. This is an algorithm-specific metric, specified in number of bits.

random - [FIPS 140-2 control input] the source of randomness for this key generator

engineGenerateKey

protected javax.crypto.SecretKey engineGenerateKey()

Generates a secret key.

FIPS 140-2:

FIPS Service: Key Generation

This API is part of the logical interface to the Toolkit's FIPS 140-2 cryptographic module; use of this API causes the caller to assume the FIPS 140-2 crypto officer role and accesses the following FIPS 140-2 logical interfaces:

• control input interface (API call)
• data output interface (return value)
• status output interface (exceptions)

Returns:

[FIPS 140-2 data output] [FIPS 140-2 CSP] the new key

engineInit

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

Initializes the key generator with the specified parameter set and a user-provided source of randomness.

FIPS 140-2:

FIPS Service: Initialization

This API is part of the logical interface to the Toolkit's FIPS 140-2 cryptographic module; use of this API causes the caller to assume the FIPS 140-2 user role and accesses the following FIPS 140-2 logical interfaces:

• control input interface (API call, parameters)
• data input interface (parameters)
• status output interface (exceptions)

Specified by:

engineInit in class javax.crypto.KeyGeneratorSpi

Parameters:

params - [FIPS 140-2 data input] the key generation parameters

random - [FIPS 140-2 control input] the source of randomness for this key generator

Throws:

java.security.InvalidAlgorithmParameterException - [FIPS 140-2 status output] if params is inappropriate for this key generator

Fips140ErrorStateException - [FIPS 140-2 status output] thrown if the Toolkit is not allowed to perform cryptographic operations

engineInit

protected void engineInit(java.security.SecureRandom random)

Initializes the key generator.

The strength defaults to the default length.

FIPS 140-2:

FIPS Service: Initialization

This API is part of the logical interface to the Toolkit's FIPS 140-2 cryptographic module; use of this API causes the caller to assume the FIPS 140-2 user role and accesses the following FIPS 140-2 logical interfaces:

• control input interface (API call, parameters)
• status output interface (exceptions)

Specified by:

engineInit in class javax.crypto.KeyGeneratorSpi

Parameters:

random - [FIPS 140-2 control input] the source of randomness for this generator

Throws:

Fips140ErrorStateException - [FIPS 140-2 status output] thrown if the Toolkit is not allowed to perform cryptographic operations