iaik.security.elgamal

Class ElGamalPrivateKey

java.lang.Object

iaik.pkcs.pkcs8.PrivateKeyInfo

iaik.security.elgamal.ElGamalPrivateKey

All Implemented Interfaces:

ASN1Type, java.io.Serializable, java.lang.Cloneable, java.security.Key, java.security.PrivateKey

public class ElGamalPrivateKey
extends PrivateKeyInfo

This class implements a ElGamal private key and supports ASN.1 encodig.

See Also:

Serialized Form

Field Summary

Fields inherited from class iaik.pkcs.pkcs8.PrivateKeyInfo

private_key_algorithm

Constructor Summary

Constructors

Constructor and Description
ElGamalPrivateKey(ASN1Object obj) Creates a new ElGamalPrivateKey from the given ASN.1 object.
ElGamalPrivateKey(java.math.BigInteger x, ElGamalParameterSpec parameters) Creates a new ElGamalPrivateKey from given private key value x and ElGamal parameter specification
ElGamalPrivateKey(byte[] pk) Creates a new ElGamalPrivateKey from the given DER encoded byte array.
ElGamalPrivateKey(ElGamalPrivateKeySpec keySpec) Creates a new ElGamalPrivateKey from the given ElGamalPrivateKeySpec representing the ElGamal private key value x, and the public values p, g and l.
ElGamalPrivateKey(java.io.InputStream is) Creates a new ElGamalPrivateKey from an InputStream.

Method Summary

Methods

Modifier and Type	Method and Description
protected void	decode(byte[] privateKey) Decodes a DER encoded ElGamal private key.
byte[]	encode() Returns the raw ElGamal private key (not wrapped in a PKCS#8 PrivateKeyInfo) as DER encoded ASN.1 object.
java.lang.String	getAlgorithm() Returns the name of the appertaining algorithm.
ElGamalParameterSpec	getParams() Returns the key parameters.
java.math.BigInteger	getX() Returns the private value x as BigInteger.
int	hashCode() Returns a hash code for this object.
java.lang.String	toString() Returns a string that represents the contents of this private key.

Methods inherited from class iaik.pkcs.pkcs8.PrivateKeyInfo

clone, createPrivateKeyInfo, decode, equals, getAlgorithmID, getEncoded, getFormat, getPrivateKey, getPrivateKey, getPrivateKey, getPrivateKey, toASN1Object, writeTo

Methods inherited from class java.lang.Object

finalize, getClass, notify, notifyAll, wait, wait, wait

Constructor Detail

ElGamalPrivateKey

public ElGamalPrivateKey(java.math.BigInteger x,
                 ElGamalParameterSpec parameters)

Creates a new ElGamalPrivateKey from given private key value x and ElGamal parameter specification

Parameters:

x - the BigInteger value representing the ElGamal private key value

parameters - the ElGamal parameters p (prime modulus), g (base generator) and l (length of the private value x) as ElGamalParameterSpec

ElGamalPrivateKey

public ElGamalPrivateKey(ElGamalPrivateKeySpec keySpec)

Creates a new ElGamalPrivateKey from the given ElGamalPrivateKeySpec representing the ElGamal private key value x, and the public values p, g and l.

Parameters:

keySpec - the ElGamalPrivateKeySpec representing the private key value x, the prime modulus p, the base generator g, and the length l of the private value

See Also:

javax.crypto.spec.ElGamalPrivateKeySpec

ElGamalPrivateKey

public ElGamalPrivateKey(byte[] pk)
                  throws java.security.InvalidKeyException

Creates a new ElGamalPrivateKey from the given DER encoded byte array.

This constructor may be used for parsing an already existing ElGamal private key, wrapped into a PKCS#8 PrivateKeyInfo that is supplied as DER encoded byte array.

Parameters:

pk - the byte array holding the DER encoded private key info

Throws:

java.security.InvalidKeyException - if something is wrong with the key encoding

ElGamalPrivateKey

public ElGamalPrivateKey(ASN1Object obj)
                  throws java.security.InvalidKeyException

Creates a new ElGamalPrivateKey from the given ASN.1 object. The supplied ASN1Object represents a PKCS#8 PrivateKeyInfo holding the ElGamal private key.

Parameters:

obj - the private key ASN.1 data structure

Throws:

java.security.InvalidKeyException - if something is wrong with the key encoding

ElGamalPrivateKey

public ElGamalPrivateKey(java.io.InputStream is)
                  throws java.io.IOException,
                         java.security.InvalidKeyException

Creates a new ElGamalPrivateKey from an InputStream.

This constructor may be used for parsing an already existing ElGamal private key, wrapped into a PKCS#8 PrivateKeyInfo that is supplied as DER encoded byte array.

Parameters:

is - the input stream with the data to be read to initialize the private key

Throws:

java.io.IOException - if an I/O error occurs

java.security.InvalidKeyException - if something is wrong with the key encoding

Method Detail

decode

protected void decode(byte[] privateKey)
               throws java.security.InvalidKeyException

Decodes a DER encoded ElGamal private key.

From the given DER encoded byte array an ASN.1 object is created and parsed for the private key value x and the ElGamal parameters prime p and base g, and - if included - the length l of the private value x.

This method is protected and typically will not be used by an application. Rather it is used by the parent PKCS#8 PrivateKeyInfo class for decoding the inherent ElGamal private key.

Specified by:

decode in class PrivateKeyInfo

Parameters:

privateKey - the ElGamal private key as DER encoded ASN.1 object

Throws:

java.security.InvalidKeyException - if the given key is not a ElGamal private key

encode

public byte[] encode()

Returns the raw ElGamal private key (not wrapped in a PKCS#8 PrivateKeyInfo) as DER encoded ASN.1 object. This method typically may not be used by an application. Rather it is used by the parent X.509 PrivateKeyInfo class for encoding the inherent ElGamal private key.

Specified by:

encode in class PrivateKeyInfo

Returns:

a byte array holding the ElGamal private key as a DER encoded ASN.1 data structure

getX

public java.math.BigInteger getX()

Returns the private value x as BigInteger.

Returns:

the private value x as BigInteger

getParams

public ElGamalParameterSpec getParams()

Returns the key parameters.

Returns:

the key parameters as ElGamalParameterSpec

getAlgorithm

public java.lang.String getAlgorithm()

Returns the name of the appertaining algorithm.

Specified by:

getAlgorithm in interface java.security.Key

Specified by:

getAlgorithm in class PrivateKeyInfo

Returns:

the string "ElGamal"

hashCode

public int hashCode()

Returns a hash code for this object.

Overrides:

hashCode in class PrivateKeyInfo

Returns:

the hash code

toString

public java.lang.String toString()

Returns a string that represents the contents of this private key.

Overrides:

toString in class PrivateKeyInfo

Returns:

the string representation