/*
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance
* with the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing,
* software distributed under the License is distributed on an
* "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
* KIND, either express or implied. See the License for the
* specific language governing permissions and limitations
* under the License.
*/
package org.apache.sshd.common.kex;
import java.math.BigInteger;
import java.security.KeyFactory;
import java.security.KeyPair;
import java.security.KeyPairGenerator;
import java.security.PublicKey;
import javax.crypto.KeyAgreement;
import javax.crypto.spec.DHParameterSpec;
import javax.crypto.spec.DHPublicKeySpec;
import org.apache.sshd.common.Digest;
import org.apache.sshd.common.Factory;
import org.apache.sshd.common.digest.SHA1;
import org.apache.sshd.common.util.SecurityUtils;
/**
* Diffie-Hellman key generator.
*
* @author <a href="mailto:dev@mina.apache.org">Apache MINA SSHD Project</a>
*/
public class DH extends AbstractDH {
private BigInteger p;
private BigInteger g;
private BigInteger e; // my public key
private byte[] e_array;
private BigInteger f; // your public key
private KeyPairGenerator myKpairGen;
private KeyAgreement myKeyAgree;
private Factory<Digest> factory;
public DH() throws Exception {
this(new SHA1.Factory());
}
public DH(Factory<Digest> factory) throws Exception {
myKpairGen = SecurityUtils.getKeyPairGenerator("DH");
myKeyAgree = SecurityUtils.getKeyAgreement("DH");
this.factory = factory;
}
public byte[] getE() throws Exception {
if (e == null) {
DHParameterSpec dhSkipParamSpec = new DHParameterSpec(p, g);
myKpairGen.initialize(dhSkipParamSpec);
KeyPair myKpair = myKpairGen.generateKeyPair();
myKeyAgree.init(myKpair.getPrivate());
e = ((javax.crypto.interfaces.DHPublicKey) (myKpair.getPublic())).getY();
e_array = e.toByteArray();
}
return e_array;
}
protected byte[] calculateK() throws Exception {
KeyFactory myKeyFac = SecurityUtils.getKeyFactory("DH");
DHPublicKeySpec keySpec = new DHPublicKeySpec(f, p, g);
PublicKey yourPubKey = myKeyFac.generatePublic(keySpec);
myKeyAgree.doPhase(yourPubKey, true);
return myKeyAgree.generateSecret();
}
public void setP(byte[] p) {
setP(new BigInteger(p));
}
public void setG(byte[] g) {
setG(new BigInteger(g));
}
public void setF(byte[] f) {
setF(new BigInteger(f));
}
public BigInteger getP() {
return p;
}
public void setP(BigInteger p) {
this.p = p;
}
public BigInteger getG() {
return g;
}
public void setG(BigInteger g) {
this.g = g;
}
public void setF(BigInteger f) {
this.f = f;
}
@Override
public Digest getHash() throws Exception {
return factory.create();
}
}