oracle.security.crypto.core

Class DHParameterGenerator

java.lang.Object

oracle.security.crypto.core.DHParameterGenerator

public class DHParameterGenerator
extends java.lang.Object

Performs normative generation of (static) Diffie-Hellman domain parameters, as specified in X9.42.

Normally, Diffie-Hellmain parameters are distributed (and generated) by a central agency agreed upon by participating parties, so a DHParameterGenerator will be invoked far less often than, say, a generator for RSA, DSA (or DH) keypairs.

Parameter generation is also similarly resource intensive: for example, generation of the sample parameters given in Annex D of X9.42 takes about 100 seconds on a Pentium-based JVM.

See Also:

DHParams

Constructor Summary

Constructors

Constructor and Description
DHParameterGenerator() Constructs a new, uninitialized DHParameterGenerator instance.

Method Summary

Methods

Modifier and Type	Method and Description
DHParams	generateParameters() Generates Diffie-Hellman parameters using the algorithms specified in Annex B, X9.42.
java.lang.String	getAlgorithm() Returns "Diffie-Hellman".
void	initialize(int L, int m) Initialize this DHParameterGenerator with the given bit lengths for p and q, and the default RandomBitsSource.
void	initialize(int L, int m, RandomBitsSource rbs) Initialize this DHParameterGenerator of the given bit lengths and RandomBitsSource.

Methods inherited from class java.lang.Object

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

Constructor Detail

DHParameterGenerator

public DHParameterGenerator()

Constructs a new, uninitialized DHParameterGenerator instance.

Method Detail

initialize

public void initialize(int L,
              int m)

Initialize this DHParameterGenerator with the given bit lengths for p and q, and the default RandomBitsSource.

Parameters:

L - the bit length of p; L=256n, n>=4

m - the bit length of q; m>=160

initialize

public void initialize(int L,
              int m,
              RandomBitsSource rbs)

Initialize this DHParameterGenerator of the given bit lengths and RandomBitsSource.

Parameters:

L - the bit length of p; L=256n, n>=4

m - the bit length of q; m>=160

rbs - the random bit source used to generate the parameters

getAlgorithm

public java.lang.String getAlgorithm()

Returns "Diffie-Hellman".

generateParameters

public DHParams generateParameters()

Generates Diffie-Hellman parameters using the algorithms specified in Annex B, X9.42. The generator instance should be initialized before this method is invoked (otherwise an exception is thrown.)

Returns:

A DHParams object of the specified sizes.