iaik.security.elgamal

Class ElGamalParameters

java.lang.Object

java.security.AlgorithmParametersSpi

iaik.security.elgamal.ElGamalParameters

public class ElGamalParameters
extends java.security.AlgorithmParametersSpi

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

Constructor Summary

Constructors

Constructor and Description
ElGamalParameters() 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 DER byte array.
protected java.security.spec.AlgorithmParameterSpec	engineGetParameterSpec(java.lang.Class paramSpec) Returns the ElGamal parameters as transparent ElGamal parameter specification of the given class type.
protected void	engineInit(java.security.spec.AlgorithmParameterSpec paramSpec) Initializes this ElGamalParameters with prime modulus p, base generator g and length l of the private value x, derived from the given ElGamalParameterSpec.
protected void	engineInit(byte[] params) Initializes this ElGamalParameters object from the given DER encoded byte array.
protected void	engineInit(byte[] params, java.lang.String format) Inits the parameters from a DER encoded byte array.
protected java.lang.String	engineToString() Returns a String representation of the parameters.
int	hashCode() Returns a hash code for this object.

Methods inherited from class java.lang.Object

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

Constructor Detail

ElGamalParameters

public ElGamalParameters()

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

Method Detail

engineGetEncoded

protected byte[] engineGetEncoded()
                           throws java.io.IOException

Returns the parameters as DER byte array.

A SEQUENCE ASN.1 object is created for holding prime modulus p, base generator g, and - if available - length l of the private value x; subsequently this SEQUENCE object is DER encoded to get the required byte array.

Specified by:

engineGetEncoded in class java.security.AlgorithmParametersSpi

Returns:

the ElGamal 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 DER byte array.

Format is ignored. Only DER encoding is supported at this time. Only calls engineGetEncoded() for returning the ElGamal parameters as DER encoded byte array, 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 ElGamal 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 ElGamal parameters as transparent ElGamal parameter specification of the given class type.

Specified by:

engineGetParameterSpec in class java.security.AlgorithmParametersSpi

Parameters:

paramSpec - the desired parameter specification class

Returns:

the ElGamal parameters as AlgorithmParaneterSpec

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 ElGamalParameters with prime modulus p, base generator g and length l of the private value x, derived from the given ElGamalParameterSpec.

Specified by:

engineInit in class java.security.AlgorithmParametersSpi

Parameters:

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

Throws:

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

engineInit

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

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

From the given byte array an ASN.1 object is created to be parsed for the required prime modulus p, base generator g and - if included - length l of the private value x.

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 a DER encoded byte array. Format is ignored.

Only calls engineInit(params) for initializing this ElGamalParameters 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

hashCode

public int hashCode()

Returns a hash code for this object.

Overrides:

hashCode in class java.lang.Object

Returns:

the hash code

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 ElGamalParameters object