iaik.security.dsa
Class DSAParameters

java.lang.Object
  |
  +--java.security.AlgorithmParametersSpi
        |
        +--iaik.security.dsa.DSAParameters

public class DSAParameters

extends AlgorithmParametersSpi

This class represents DSA parameters in opaque form.

DSAParamters may be generated provider independently by calling one of the AlgorithmParameters.getInstance methods. Subsequently the new AlgorithmParamters object must be initialized with a proper DSA parameter specification or a DER encoded byte array, e.g.:

 DSAParameterspec dsaParamSpec = ...;
 AlgorithmParameters params = AlgorithmParameters.getInstance("DSA", "IAIK");
 params.init(dsaParamSpec);
 

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

Version:

File Revision 8

Constructor Summary

DSAParameters()
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 DSA parameters as transparent parameter specification of the given class type.
protected void	engineInit(AlgorithmParameterSpec paramSpec) Initializes this DSAParameters with the given DSAParameterSpec.
protected void	engineInit(byte[] params) Initializes this DSAParameters 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

DSAParameters

public DSAParameters()

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

Method Detail

engineGetEncoded

protected byte[] engineGetEncoded()
                           throws IOException

Returns the parameters as DER byte array.

Encodes the DSA parameters as ASN.1 SEQUENCE.

Overrides:

engineGetEncoded in class AlgorithmParametersSpi

Returns:

the DSA 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() for encoding the DSA parameters as ASN.1 SEQUENCE, regardless of what is specified in the format string.

Overrides:

engineGetEncoded in class AlgorithmParametersSpi

Parameters:

format - the encoding format; ignored

Returns:

the DSA parameters as DER byte array

Throws:

IOException - if an encoding error occurs

engineGetParameterSpec

protected AlgorithmParameterSpec engineGetParameterSpec(Class paramSpec)
                                                 throws InvalidParameterSpecException

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

Overrides:

engineGetParameterSpec in class AlgorithmParametersSpi

Parameters:

paramSpec - the desired parameter specification class (DSAParameterSpec)

Returns:

the DSA parameters as DSAParameterSpec

Throws:

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

engineInit

protected void engineInit(AlgorithmParameterSpec paramSpec)
                   throws InvalidParameterSpecException

Initializes this DSAParameters with the given DSAParameterSpec.

Overrides:

engineInit in class AlgorithmParametersSpi

Parameters:

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

Throws:

InvalidParameterSpecException - if the given parameter specification is not a DSAParameterSpec

engineInit

protected void engineInit(byte[] params)
                   throws IOException

Initializes this DSAParameters 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

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 DSAParamters 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 DSAParameters object