iaik.security.cipher
Class CAST128Parameters

java.lang.Object
  |
  +--java.security.AlgorithmParametersSpi
        |
        +--iaik.security.cipher.CAST128Parameters

public class CAST128Parameters

extends AlgorithmParametersSpi

This class represents CAST paramters in opaque form and may be used for generating opaque CAST parameters and converting them between various formats.

The parameters specified for the CAST algorithm in RFC 2144 consist of an initialization vector (of eight octets) and the keyLength:

 Parameters ::= SEQUENCE {
      iv         OCTET STRING DEFAULT 0,  -- Initialization vector
      keyLength  INTEGER                  -- Key length, in bits
 }
 

If no initialization vector is included it defaults to an IV of all zeros.

CAST128Paramters can be generated provider independently by calling one of the AlgorithmParameters.getInstance methods for the algorithm in mind. Subsequently the new AlgorithmParamters object must be initialized with a proper CAST128 parameter specification or a DER encoded byte array, e.g.:

 CAST128ParameterSpec castParamSpec = ...;
 AlgorithmParameters params = AlgorithmParameters.getInstance("CAST128", "IAIK");
 params.init(castParamsSpec);
 

For obtaining CAST parameters in transparent representation from an opaque CAST128Paramters object, the getParameterSpec method can be used; for obtaining the parameters as DER encoded ASN.1 object, use getEncoded.

Version:

File Revision 9

Constructor Summary

CAST128Parameters()
The default constructor.

Method Summary

protected byte[]	engineGetEncoded() Returns the parameters as DER byte array.
protected byte[]	engineGetEncoded(String format) Returns the parameters as a DER byte array.
protected AlgorithmParameterSpec	engineGetParameterSpec(Class paramSpec) Returns the CAST parameters as transparent CAST parameter specification of the given class type.
protected void	engineInit(AlgorithmParameterSpec paramSpec) Initializes this CAST128Parameters with the parameter values from a given CAST128ParameterSpec.
protected void	engineInit(byte[] params) Initializes this CAST128Parameters object from the given DER encoded byte array.
protected void	engineInit(byte[] params, String format) Inits the parameters from an DER encoded byte array.
protected String	engineToString() Returns a String representation of the parameters.

Methods inherited from class java.lang.Object

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

Constructor Detail

CAST128Parameters

public CAST128Parameters()

The default constructor. Only internally used for creating a CAST128Parameters object. Applications shall use one of the AlgorithmParameters.getInstance factory methods for obtaining CAST128Parameters.

Method Detail

engineGetEncoded

protected byte[] engineGetEncoded()
                           throws IOException

Returns the parameters as DER byte array.

Overrides:

engineGetEncoded in class AlgorithmParametersSpi

Returns:

the CAST parameters as DER byte array

Throws:

IOException - if an encoding error occurs

engineGetEncoded

protected byte[] engineGetEncoded(String format)
                           throws IOException

Returns the parameters as a DER byte array.

Format is ignored. Only DER encoding is supported at this time. This method only calls engineGetEncoded(), regardless of what is specified in the format string.

Overrides:

engineGetEncoded in class AlgorithmParametersSpi

Parameters:

format - the encoding format; ignored

Returns:

the CAST parameters as DER byte array

Throws:

IOException - if an encoding error occurs

engineGetParameterSpec

protected AlgorithmParameterSpec engineGetParameterSpec(Class paramSpec)
                                                 throws InvalidParameterSpecException

Returns the CAST parameters as transparent CAST parameter specification of the given class type.

Overrides:

engineGetParameterSpec in class AlgorithmParametersSpi

Parameters:

paramSpec - the desired parameter specification class (CAST128ParameterSpec)

Returns:

the parameters as CAST128ParameterSpec

Throws:

InvalidParameterSpecException - if the paramters cannot be converted to the desired parameter specification

engineInit

protected void engineInit(AlgorithmParameterSpec paramSpec)
                   throws InvalidParameterSpecException

Initializes this CAST128Parameters with the parameter values from a given CAST128ParameterSpec.

Overrides:

engineInit in class AlgorithmParametersSpi

Parameters:

paramSpec - the parameter specification, which has to be a CAST128ParameterSpec

Throws:

InvalidParameterSpecException - if the given parameter specification is not a CAST128ParameterSpec or the included parameters are invalid

engineInit

protected void engineInit(byte[] params)
                   throws IOException

Initializes this CAST128Parameters object from the given DER encoded byte array.

Overrides:

engineInit in class AlgorithmParametersSpi

Parameters:

params - the DER encoded byte array

Throws:

IOException - if an error occurs when decoding the given byte array or the derived parameter values are invalid

engineInit

protected void engineInit(byte[] params,
                          String format)
                   throws IOException

Inits the parameters from an DER encoded byte array. Format is ignored. Only calls {engineInit(params) for initializing this CAST128Paramters object from the given DER encoded byte array, regardless of what is specified in the format string.

Overrides:

engineInit in class AlgorithmParametersSpi

Parameters:

params - the DER encoded byte array

format - the encoding format; ignored

Throws:

IOException - if an error occurs when decoding the given byte array

engineToString

protected String engineToString()

Returns a String representation of the parameters.

Overrides:

engineToString in class AlgorithmParametersSpi

Returns:

a String representation of this CAST128Parameters object