我一直在做很多研究，但找不到解决这个问题的方法。我已经花了好几个小时，我无法理解，所以我希望有人比我更有经验，可以提供帮助。这个程序可能不是最佳实践，但它适用于作业。
我正在使用RSA传输公钥，但更重要的是，我正在尝试将Bob（服务器）的Diffie Hellman参数传输到Alice（客户端）。运行程序时出现以下错误：
线程“main”中的异常java.security.spec.InvalidKeySpecException： 不恰当的密钥规范 com.sun.crypto.provider.DHKeyFactory.engineGeneratePublic（DHKeyFactory.java:85） 在java.security.KeyFactory.generatePublic（KeyFactory.java:334）at client.Client.main（Client.java:114）引起： java.security.InvalidKeyException：解析密钥编码时出错 com.sun.crypto.provider.DHPublicKey。（DHPublicKey.java:178）at at com.sun.crypto.provider.DHKeyFactory.engineGeneratePublic（DHKeyFactory.java:78） ... 2更多引起：java.io.IOException： DerInputStream.getLength（）：lengthTag = 127，太大了。在 sun.security.util.DerInputStream.getLength（DerInputStream.java:561） 在sun.security.util.DerValue.init（DerValue.java：365）at sun.security.util.DerValue。（DerValue.java:320）at com.sun.crypto.provider.DHPublicKey。（DHPublicKey.java:125）... 还有3个
这是代码： Client.java：
package client;
import java.io.*;
import java.security.*;
import javax.crypto.*;
import java.util.*;
import java.net.*;
import java.util.logging.Level;
import java.util.logging.Logger;
import java.io.ObjectInputStream;
import java.io.ObjectOutputStream;
import javax.crypto.spec.DHParameterSpec;
import java.security.spec.*;
class Client{
private static PublicKey publicKey = null;
private static PrivateKey privateKey = null;
private static PublicKey rsaBobPub = null;
private static SecretKey SecretSharedKeyCipher = null;
private static SecretKey SecretSharedKeyIntgSend = null;
private static SecretKey SecretSharedKeyIntRecv = null;
private static KeyAgreement aKeyAgreement = null;
public static void main(String args[]) throws ClassNotFoundException, `IOException, NoSuchAlgorithmException, InvalidKeyException, NoSuchPaddingException, IllegalBlockSizeException, BadPaddingException, InvalidAlgorithmParameterException, InvalidParameterSpecException, InvalidKeySpecException{`
Client client = new Client();
KeyPairGenerator keyGen;
byte[] alicePub;
Cipher cipher2;
byte[] encryptedDH = null;
byte[] bobEncryptedDH = null;
OutputStream dh;
InputStream bobDHConn;
Socket connection = new Socket("localhost", 4129);
//Generate Keys & then send to Bob
keyGen = KeyPairGenerator.getInstance("RSA");
keyGen.initialize(2048);
KeyPair keyPair = keyGen.genKeyPair();
publicKey = keyPair.getPublic();
privateKey = keyPair.getPrivate();
//Send Public Key to Bob
ObjectOutputStream toBob = new ObjectOutputStream(connection.getOutputStream());
toBob.writeObject(publicKey);
//Receive Bob's Public Key
ObjectInputStream fromBob;
fromBob = new ObjectInputStream(connection.getInputStream());
rsaBobPub = (PublicKey) fromBob.readObject();
//SET UP DIFFIE HELLMAN PROTOCOL
//For some reason, when receiving Bob's DH param, I am getting a lot of issues.
//Exchange DH info
DHParameterSpec paramSpec;
AlgorithmParameterGenerator paramGen = AlgorithmParameterGenerator.getInstance("DH");
paramGen.init(512);
AlgorithmParameters parameters = paramGen.generateParameters();
paramSpec = (DHParameterSpec) parameters.getParameterSpec(DHParameterSpec.class);
//Generate Key Pair
KeyPairGenerator aliceKpGen = KeyPairGenerator.getInstance("DH");
aliceKpGen.initialize(paramSpec);
KeyPair aliceKp = aliceKpGen.generateKeyPair();
aKeyAgreement = KeyAgreement.getInstance("DH");
aKeyAgreement.init(aliceKp.getPrivate());
alicePub = aliceKp.getPublic().getEncoded();
//System.out.println(aliceKp.getPublic())
//System.out.println(aliceKp.getPublic().getEncoded())
//Send Alice's encrypted DH byte info to Bob
/* cipher2 = Cipher.getInstance("RSA/ECB/PKCS1Padding");
cipher2.init(Cipher.ENCRYPT_MODE, rsaBobPub);
encryptedDH = cipher2.doFinal(alicePub);
System.out.print(encryptedDH);
*/
dh = connection.getOutputStream();
dh.write(alicePub);
//Recieve Bob's DH Info
bobDHConn = connection.getInputStream();
int length;
byte[] bobDH = null;
while((length = bobDHConn.available()) == 0){
bobDH = new byte[length];
int i = 0;
while(i < length){
i+= bobDHConn.read(bobDH, i, length - i);
}
}
//NOT WORKING
KeyFactory clientKeyFac = KeyFactory.getInstance("DH");
X509EncodedKeySpec x509KeySpec = new X509EncodedKeySpec(bobDH);
PublicKey bobsDHPubKey = clientKeyFac.generatePublic(x509KeySpec);
aKeyAgreement.doPhase(bobsDHPubKey, true);
//Generate AES Secret Keys
SecretKey aesKeyGen = aKeyAgreement.generateSecret("AES");
}
}
Server.java
package server;
import java.io.*;
import java.security.*;
import javax.crypto.*;
import java.util.*;
import java.net.*;
import java.util.logging.Level;
import java.util.logging.Logger;
import java.io.ObjectInputStream;
import java.io.ObjectOutputStream;
import java.security.spec.InvalidKeySpecException;
import java.security.spec.X509EncodedKeySpec;
import javax.crypto.interfaces.DHPublicKey;
import javax.crypto.spec.DHParameterSpec;
public class Server{
private static int port = 4129;
private static PublicKey publicKey = null;
private static PrivateKey privateKey = null;
private static PublicKey rsaAlicePub = null;
private static ServerSocket server = null;
private static SecretKey SecretSharedKeyCipher = null;
private static SecretKey SecretSharedKeyIntgSend = null;
private static SecretKey SecretSharedKeyIntRecv = null;
public static void main(String args[]) throws ClassNotFoundException, NoSuchAlgorithmException, IOException, NoSuchPaddingException, InvalidKeyException, IllegalBlockSizeException, BadPaddingException, InvalidKeySpecException, InvalidAlgorithmParameterException{
//Declarations
Server serv = new Server();
server = new ServerSocket(4129);
server.setReuseAddress(true);
KeyPairGenerator keyGen;
byte[] cipherText = null;
InputStream input = null;
byte[] data = null;
byte[] decryptedDH;
InputStream DH = null;
byte[] DHinfo = null;
int length;
byte[] aliceEncryptedDH = null;
SecretKey keyGenDH= null;
InputStream aliceDH = null;
Cipher cipher;
PublicKey bobDHPub = null;
OutputStream sendDH;
//String message = "bbbbbbbbbbbbbb";
String message = "bbbbbbb";
Socket client = server.accept();
//Get Public Key froM Alice
ObjectInputStream alicePK;
alicePK = new ObjectInputStream(client.getInputStream());
rsaAlicePub = (PublicKey)alicePK.readObject();
//Generate Bob's keys
keyGen = KeyPairGenerator.getInstance("RSA");
keyGen.initialize(2048);
KeyPair keyPair = keyGen.genKeyPair();
privateKey = keyPair.getPrivate();
publicKey = keyPair.getPublic();
//Send Bob's public Key to Alice
ObjectOutputStream bobPK;
bobPK = new ObjectOutputStream(client.getOutputStream());
bobPK.writeObject(publicKey);
//Exchange information for DH
//Decrypt received information using Bob PK
//You can assume that Bob selects the public parameters of Diffie‐Hellman protocol, and send them to Alice
DH = client.getInputStream();
while((length = DH.available()) == 0);
int i = 0;
DHinfo = new byte[length];
while (i < length) {
i += DH.read(DHinfo, i, length - i);
}
/*
cipher = Cipher.getInstance("RSA/ECB/PKCS1Padding");
cipher.init(Cipher.DECRYPT_MODE, privateKey);
decryptedDH = cipher.doFinal(DHinfo);
*/
KeyFactory clientKeyFac = KeyFactory.getInstance("DH");
X509EncodedKeySpec x509KeySpec = new X509EncodedKeySpec(DHinfo);
bobDHPub = clientKeyFac.generatePublic(x509KeySpec);
DHParameterSpec dhParamSpec = ((DHPublicKey) bobDHPub).getParams();
//Create Bob DH Keys
KeyPairGenerator bobKpGen = KeyPairGenerator.getInstance("DH");
bobKpGen.initialize(dhParamSpec);
KeyPair bobsKeys = bobKpGen.generateKeyPair();
KeyAgreement bobKeyAgreement = KeyAgreement.getInstance("DH");
bobKeyAgreement.init(bobsKeys.getPrivate());
bobKeyAgreement.doPhase(bobDHPub, true);
//Send Bob's DH Parameters to Alice
//send bobsKeys.getPublic().getEncoded()
sendDH = client.getOutputStream();
sendDH.write(bobsKeys.getPublic().getEncoded());
//Encrypt message.getBytes();
}
private void Server() throws IOException{
server = new ServerSocket(port);
}
}
答案 0 :(得分：2)
您从InputStream中读取的方式是错误的。首先，您不想使用可用的方法。它不会返回您认为它返回的内容，它返回的内容对您没有用。
当您将字节数组写入OutputStream并且希望另一方重建相同的字节数组时，您需要以某种方式告诉另一方字节数组的长度。最简单的方法是在前面添加长度。
在您的情况下，您已经有一个ObjectOutputStream和ObjectInputStream包裹着您的原始输出和输入流。只需使用它们。字节数组也是对象，因此您可以调用writeObject和readObject来传输它们。
在客户端：
toBob.writeObject(alicePub);
在服务器中：
DHinfo = (byte[]) alicePK.readObject();
（注意：如果您将alicePk用于多种用途，则应将fromAlice重命名为{{1}}。