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Java > Open Source Codes > com > jcraft > jsch > jce > DH


1 /* -*-mode:java; c-basic-offset:2; indent-tabs-mode:nil -*- */
2 /*
3 Copyright (c) 2002,2003,2004,2005,2006 ymnk, JCraft,Inc. All rights reserved.
4
5 Redistribution and use in source and binary forms, with or without
6 modification, are permitted provided that the following conditions are met:
7
8   1. Redistributions of source code must retain the above copyright notice,
9      this list of conditions and the following disclaimer.
10
11   2. Redistributions in binary form must reproduce the above copyright
12      notice, this list of conditions and the following disclaimer in
13      the documentation and/or other materials provided with the distribution.
14
15   3. The names of the authors may not be used to endorse or promote products
16      derived from this software without specific prior written permission.
17
18 THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED WARRANTIES,
19 INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
20 FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL JCRAFT,
21 INC. OR ANY CONTRIBUTORS TO THIS SOFTWARE BE LIABLE FOR ANY DIRECT, INDIRECT,
22 INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
23 LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA,
24 OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
25 LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
26 NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE,
27 EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
28 */
29
30 package com.jcraft.jsch.jce;
31
32 import java.math.BigInteger JavaDoc;
33 import java.security.*;
34 import javax.crypto.*;
35 import javax.crypto.spec.*;
36
37 public class DH implements com.jcraft.jsch.DH{
38   BigInteger JavaDoc p;
39   BigInteger JavaDoc g;
40   BigInteger JavaDoc e; // my public key
41 byte[] e_array;
42   BigInteger JavaDoc f; // your public key
43 BigInteger JavaDoc K; // shared secret key
44 byte[] K_array;
45
46   private KeyPairGenerator myKpairGen;
47   private KeyAgreement myKeyAgree;
48   public void init() throws Exception JavaDoc{
49     myKpairGen=KeyPairGenerator.getInstance("DH");
50 // myKpairGen=KeyPairGenerator.getInstance("DiffieHellman");
51 myKeyAgree=KeyAgreement.getInstance("DH");
52 // myKeyAgree=KeyAgreement.getInstance("DiffieHellman");
53 }
54   public byte[] getE() throws Exception JavaDoc{
55     if(e==null){
56       DHParameterSpec dhSkipParamSpec=new DHParameterSpec(p, g);
57       myKpairGen.initialize(dhSkipParamSpec);
58       KeyPair myKpair=myKpairGen.generateKeyPair();
59       myKeyAgree.init(myKpair.getPrivate());
60 // BigInteger x=((javax.crypto.interfaces.DHPrivateKey)(myKpair.getPrivate())).getX();
61 byte[] myPubKeyEnc=myKpair.getPublic().getEncoded();
62       e=((javax.crypto.interfaces.DHPublicKey)(myKpair.getPublic())).getY();
63       e_array=e.toByteArray();
64     }
65     return e_array;
66   }
67   public byte[] getK() throws Exception JavaDoc{
68     if(K==null){
69       KeyFactory myKeyFac=KeyFactory.getInstance("DH");
70       DHPublicKeySpec keySpec=new DHPublicKeySpec(f, p, g);
71       PublicKey yourPubKey=myKeyFac.generatePublic(keySpec);
72       myKeyAgree.doPhase(yourPubKey, true);
73       byte[] mySharedSecret=myKeyAgree.generateSecret();
74       K=new BigInteger JavaDoc(mySharedSecret);
75       K_array=K.toByteArray();
76
77 //System.err.println("K.signum(): "+K.signum()+
78 // " "+Integer.toHexString(mySharedSecret[0]&0xff)+
79 // " "+Integer.toHexString(K_array[0]&0xff));
80
81       K_array=mySharedSecret;
82     }
83     return K_array;
84   }
85   public void setP(byte[] p){ setP(new BigInteger JavaDoc(p)); }
86   public void setG(byte[] g){ setG(new BigInteger JavaDoc(g)); }
87   public void setF(byte[] f){ setF(new BigInteger JavaDoc(f)); }
88   void setP(BigInteger JavaDoc p){this.p=p;}
89   void setG(BigInteger JavaDoc g){this.g=g;}
90   void setF(BigInteger JavaDoc f){this.f=f;}
91 }
92
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