keyagreement.java

来自「一个非常好的ssh客户端实现」· Java 代码 · 共 122 行

/******************************************************************************
 *
 * Copyright (c) 1999-2003 AppGate Network Security AB. All Rights Reserved.
 * 
 * This file contains Original Code and/or Modifications of Original Code as
 * defined in and that are subject to the MindTerm Public Source License,
 * Version 2.0, (the 'License'). You may not use this file except in compliance
 * with the License.
 * 
 * You should have received a copy of the MindTerm Public Source License
 * along with this software; see the file LICENSE.  If not, write to
 * AppGate Network Security AB, Otterhallegatan 2, SE-41118 Goteborg, SWEDEN
 *
 *****************************************************************************/

package com.mindbright.jce.crypto;


import com.mindbright.jca.security.Provider;
import com.mindbright.jca.security.ProviderLookup;
import com.mindbright.jca.security.SecureRandom;
import com.mindbright.jca.security.Key;
import com.mindbright.jca.security.NoSuchAlgorithmException;
import com.mindbright.jca.security.NoSuchProviderException;
import com.mindbright.jca.security.InvalidKeyException;
import com.mindbright.jca.security.InvalidAlgorithmParameterException;
import com.mindbright.jca.security.spec.AlgorithmParameterSpec;

public class KeyAgreement {

    protected KeyAgreementSpi keyAgreementSpi;
    Provider  provider;
    String    algorithm;

    protected KeyAgreement(KeyAgreementSpi keyAgreeSpi, Provider provider,
			   String algorithm) {
	this.keyAgreementSpi = keyAgreeSpi;
	this.provider        = provider;
	this.algorithm       = algorithm;
    }

    public final String getAlgorithm() {
	return algorithm;
    }

    public static final KeyAgreement getInstance(String algorithm)
	throws NoSuchAlgorithmException
    {
	try {
	    String provider =
		ProviderLookup.findImplementingProvider("KeyAgreement",
							algorithm);
	    return getInstance(algorithm, provider);
	} catch (NoSuchProviderException e) {
	    throw new Error("Error in Signature: " + e);
	}

    }

    public static final KeyAgreement getInstance(String algorithm,
						 String provider)
	throws NoSuchAlgorithmException, NoSuchProviderException
    {
	ProviderLookup pl = ProviderLookup.getImplementation("KeyAgreement",
							     algorithm,
							     provider);
	return new KeyAgreement((KeyAgreementSpi)pl.getImpl(),
				pl.getProvider(), algorithm);
    }

    public final Provider getProvider() {
	return provider;
    }

    public final void init(Key key) throws InvalidKeyException {
	init(key, (SecureRandom)null);
    }

    public final void init(Key key, SecureRandom random)
	throws InvalidKeyException
    {
	keyAgreementSpi.engineInit(key, random);
    }

    public final void init(Key key, AlgorithmParameterSpec params)
	throws InvalidKeyException, InvalidAlgorithmParameterException
    {
	init(key, params, null);
    }

    public final void init(Key key, AlgorithmParameterSpec params,
			   SecureRandom random)
	throws InvalidKeyException, InvalidAlgorithmParameterException
    {
	keyAgreementSpi.engineInit(key, params, random);
    }

    public final Key doPhase(Key key, boolean lastPhase)
	throws InvalidKeyException, IllegalStateException
    {
	return keyAgreementSpi.engineDoPhase(key, lastPhase);
    }

    public final byte[] generateSecret() throws IllegalStateException {
	return keyAgreementSpi.engineGenerateSecret();
    }

    public final int generateSecret(byte[] sharedSecret, int offset)
	throws IllegalStateException, ShortBufferException
    {
	return keyAgreementSpi.engineGenerateSecret(sharedSecret, offset);
    }

    public final SecretKey generateSecret(String algorithm)
	throws IllegalStateException, NoSuchAlgorithmException,
	       InvalidKeyException
    {
	return keyAgreementSpi.engineGenerateSecret(algorithm);
    }

}