iaik.security.dsa

Class DSAParameters

java.lang.Object

java.security.AlgorithmParametersSpi

iaik.security.dsa.DSAParameters

public class DSAParameters
extends java.security.AlgorithmParametersSpi

This class represents DSA parameters in opaque form.

DSAParameters may be generated provider independently by calling one of the AlgorithmParameters.getInstance methods. Subsequently the new AlgorithmParameters 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 DSAParameters 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

Constructors

Constructor and Description
DSAParameters() The default constructor.

Method Summary

Methods

Modifier and Type	Method and Description
protected byte[]	engineGetEncoded() Returns the parameters as DER byte array.
protected byte[]	engineGetEncoded(java.lang.String format) Returns the parameters as a DER byte array.
protected java.security.spec.AlgorithmParameterSpec	engineGetParameterSpec(java.lang.Class paramSpec) Returns the DSA parameters as transparent parameter specification of the given class type.
protected void	engineInit(java.security.spec.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, java.lang.String format) Inits the parameters from an DER encoded byte array.
protected java.lang.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 java.io.IOException

Returns the parameters as DER byte array.

Encodes the DSA parameters as ASN.1 SEQUENCE.

Specified by:

engineGetEncoded in class java.security.AlgorithmParametersSpi

Returns:

the DSA parameters as DER byte array

Throws:

java.io.IOException - if an encoding error occurs

engineGetEncoded

protected byte[] engineGetEncoded(java.lang.String format)
                           throws java.io.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.

Specified by:

engineGetEncoded in class java.security.AlgorithmParametersSpi

Parameters:

format - the encoding format; ignored

Returns:

the DSA parameters as DER byte array

Throws:

java.io.IOException - if an encoding error occurs

engineGetParameterSpec

protected java.security.spec.AlgorithmParameterSpec engineGetParameterSpec(java.lang.Class paramSpec)
                                                                    throws java.security.spec.InvalidParameterSpecException

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

Specified by:

engineGetParameterSpec in class java.security.AlgorithmParametersSpi

Parameters:

paramSpec - the desired parameter specification class (DSAParameterSpec)

Returns:

the DSA parameters as DSAParameterSpec

Throws:

java.security.spec.InvalidParameterSpecException - if the parameters cannot be converted to the desired parameter specification

engineInit

protected void engineInit(java.security.spec.AlgorithmParameterSpec paramSpec)
                   throws java.security.spec.InvalidParameterSpecException

Initializes this DSAParameters with the given DSAParameterSpec.

Specified by:

engineInit in class java.security.AlgorithmParametersSpi

Parameters:

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

Throws:

java.security.spec.InvalidParameterSpecException - if the given parameter specification is not a DSAParameterSpec

engineInit

protected void engineInit(byte[] params)
                   throws java.io.IOException

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

Specified by:

engineInit in class java.security.AlgorithmParametersSpi

Parameters:

params - the DER encoded byte array

Throws:

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

engineInit

protected void engineInit(byte[] params,
              java.lang.String format)
                   throws java.io.IOException

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

Specified by:

engineInit in class java.security.AlgorithmParametersSpi

Parameters:

params - the DER encoded byte array

format - the encoding format; ignored

Throws:

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

engineToString

protected java.lang.String engineToString()

Returns a String representation of the parameters.

Specified by:

engineToString in class java.security.AlgorithmParametersSpi

Returns:

a String representation of this DSAParameters object