javax.crypto.spec
Class DHParameterSpec

java.lang.Object
  javax.crypto.spec.DHParameterSpec

All Implemented Interfaces:

AlgorithmParameterSpec

public class DHParameterSpec
extends Object
implements AlgorithmParameterSpec

This class specifies the set of parameters used with the Diffie-Hellman algorithm, as specified in PKCS #3: Diffie-Hellman Key-Agreement Standard.

A central authority generates parameters and gives them to the two entities seeking to generate a secret key. The parameters are a prime p, a base g, and optionally the length in bits of the private value, l.

It is possible that more than one instance of parameters may be generated by a given central authority, and that there may be more than one central authority. Indeed, each individual may be its own central authority, with different entities having different parameters.

Version:

$Id: DHParameterSpec.java 1913 2007-08-08 02:41:53Z jpeters $

Author:

Patric Kabus, Jan Peters

Field Summary

private BigInteger	g_ The base generator.
private int	l_ The size in bits of the random exponent (private value).
private BigInteger	p_ The prime modulus.

Constructor Summary

DHParameterSpec(BigInteger p, BigInteger g)
Constructs a parameter set for Diffie-Hellman, using a prime modulus p and a base generator g.

DHParameterSpec(BigInteger p, BigInteger g, int l)
Constructs a parameter set for Diffie-Hellman, using a prime modulus p, a base generator g, and the size in bits, l, of the random exponent (private value).

Method Summary

BigInteger	getG() Returns the base generator g.
int	getL() Returns the size in bits, l, of the random exponent (private value).
BigInteger	getP() Returns the prime modulus p.

Methods inherited from class java.lang.Object

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

Field Detail

g_

private BigInteger g_

The base generator.

p_

private BigInteger p_

The prime modulus.

l_

private int l_

The size in bits of the random exponent (private value).

Constructor Detail

DHParameterSpec

public DHParameterSpec(BigInteger p,
                       BigInteger g)

Constructs a parameter set for Diffie-Hellman, using a prime modulus p and a base generator g.

Parameters:

p - the prime modulus.

g - the base generator.

DHParameterSpec

public DHParameterSpec(BigInteger p,
                       BigInteger g,
                       int l)

Constructs a parameter set for Diffie-Hellman, using a prime modulus p, a base generator g, and the size in bits, l, of the random exponent (private value).

Parameters:

p - the prime modulus.

g - the base generator.

l - the size in bits of the random exponent (private value).

Method Detail

getP

public BigInteger getP()

Returns the prime modulus p.

Returns:

the prime modulus p.

getG

public BigInteger getG()

Returns the base generator g.

Returns:

the base generator g.

getL

public int getL()

Returns the size in bits, l, of the random exponent (private value).

Returns:

the size in bits, l, of the random exponent (private value), or 0 if this size has not been set