Java Diffie-Hellman密钥交换 [英] Java Diffie-Hellman key exchange

问题描述

我正在尝试执行代码以执行Diffie-Hellman密钥交换。我从在线示例中获取了代码（现在忘记了）。
我必须导入bouncycastle.jar，我假设它会一直执行直到执行。

I'm trying to execute code to perform the Diffie-Hellman key exchange. I sourced the code from an example online (forget where now). I had to import the bouncycastle.jar, which I assumed worked up until execution.

我的代码：

package testproject;

import java.math.BigInteger;
import java.security.KeyPair;
import java.security.KeyPairGenerator;
import java.security.MessageDigest;
import java.security.SecureRandom;
import java.security.Security;
import javax.crypto.KeyAgreement;
import javax.crypto.spec.DHParameterSpec;

public class KeyGen {

  private static BigInteger g512 = new BigInteger("1234567890", 16);
  //generates a random, non-negative integer for Base

  private static BigInteger p512 = new BigInteger("1234567890", 16);
  //generates a random, non-negative integer for Prime

  public static void main(String[] args) throws Exception {
    Security.addProvider(new org.bouncycastle.jce.provider.BouncyCastleProvider());
    DHParameterSpec dhParams = new DHParameterSpec(p512, g512);
    //Specify parameters to use for the algorithm
    KeyPairGenerator keyGen = KeyPairGenerator.getInstance("DH", "BC");
    //Define specific algorithm to use "diffie-hellman", with provider "bc"

    keyGen.initialize(dhParams, new SecureRandom());
    //initialize with parameters & secure random seed

    KeyAgreement aKeyAgree = KeyAgreement.getInstance("DH", "BC");
    //define algorithm for A's key agreement
    KeyPair aPair = keyGen.generateKeyPair();
    //generate keyPair for A

    KeyAgreement bKeyAgree = KeyAgreement.getInstance("DH", "BC");
    //define algorithm for B's key agreement
    KeyPair bPair = keyGen.generateKeyPair();
    //generate keyPair for B

    aKeyAgree.init(aPair.getPrivate());
    //initialize A's keyAgreement with A's private key
    bKeyAgree.init(bPair.getPrivate());
    //initialize B's keyAgreement with B's private key

    aKeyAgree.doPhase(bPair.getPublic(), true);
    //do last phase of A's keyAgreement with B's public key
    bKeyAgree.doPhase(aPair.getPublic(), true);
    //do last phase of B's keyAgreement with A's public key

    MessageDigest hash = MessageDigest.getInstance("SHA1", "BC");

    System.out.println(new String(hash.digest(aKeyAgree.generateSecret())));
    //generate secret key for A, hash it.
    System.out.println(new String(hash.digest(bKeyAgree.generateSecret())));
    //generate secret key for B, hash it.
  }
}

这是引起问题的行：

KeyPair aPair = keyGen.generateKeyPair();

我对错误的含义感到困惑，因为我发现了每种方法返回未知来源。

I'm confused as to what the error is, as I've found each of the methods it's returning 'unknown source' for.

对此有任何了解，将不胜感激。

Any light shed on this would be much appreciated.

续（编辑）：
Java-Diffie-Hellman加密-错误的输出

推荐答案

您已经更喜欢bouncycastle版本。但出于学习目的，我实现了一个helloworld版本。也许对那些只想在纯Java中不依赖地使用Diffie-Hellman的人有帮助：

You already preferred bouncycastle version. But I implemented a little helloworld version of it for learning purposes. Maybe it can be helpful for those who simply wants to use Diffie-Hellman in pure Java without dependencies:

// 1. ------------------------------------------------------------------
// This is Alice and Bob
// Alice and Bob want to chat securely. But how?

final Person alice = new Person();
final Person bob   = new Person();

//    ?                                        ?
//
//    O                                        O
//   /|\                                      /|\
//   / \                                      / \
//
//  ALICE                                     BOB

// 2. ------------------------------------------------------------------
// Alice and Bob generate public and private keys.

alice.generateKeys();
bob.generateKeys();

//
//    O                                        O
//   /|\                                      /|\
//   / \                                      / \
//
//  ALICE                                     BOB
//  _ PUBLIC KEY                              _ PUBLIC KEY
//  _ PRIVATE KEY                             _ PRIVATE KEY

// 3. ------------------------------------------------------------------
// Alice and Bob exchange public keys with each other.

alice.receivePublicKeyFrom(bob);
bob.receivePublicKeyFrom(alice);

//
//    O                                        O
//   /|\                                      /|\
//   / \                                      / \
//
//  ALICE                                     BOB
//  + public key                              + public key
//  + private key                             + private key
//  _ PUBLIC KEY <------------------------->  _ PUBLIC KEY

// 4. ------------------------------------------------------------------
// Alice generates common secret key via using her private key and Bob's public key.
// Bob generates common secret key via using his private key and Alice's public key.
// Both secret keys are equal without TRANSFERRING. This is the magic of Diffie-Helman algorithm.

alice.generateCommonSecretKey();
bob.generateCommonSecretKey();

//
//    O                                        O
//   /|\                                      /|\
//   / \                                      / \
//
//  ALICE                                     BOB
//  + public key                              + public key
//  + private key                             + private key
//  + public key                              + public key
//  _ SECRET KEY                              _ SECRET KEY

// 5. ------------------------------------------------------------------
// Alice encrypts message using the secret key and sends to Bob

alice.encryptAndSendMessage("Bob! Guess Who I am.", bob);

//
//    O                                        O
//   /|\ []-------------------------------->  /|\
//   / \                                      / \
//
//  ALICE                                     BOB
//  + public key                              + public key
//  + private key                             + private key
//  + public key                              + public key
//  + secret key                              + secret key
//  + message                                 _ MESSAGE

// 6. ------------------------------------------------------------------
// Bob receives the important message and decrypts with secret key.

bob.whisperTheSecretMessage();

//
//    O                     (((   (((   (((   \O/   )))
//   /|\                                       |
//   / \                                      / \
//
//  ALICE                                     BOB
//  + public key                              + public key
//  + private key                             + private key
//  + public key                              + public key
//  + secret key                              + secret key
//  + message                                 + message

https://github.com/firatkucuk/diffie-hellman-helloworld

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