堆栈内存溢出
  繁体   English   中英

Java密码填充错误

[英]Java Cipher padding Error

 原文  2016-09-01 16:51:19  1   2    java/ multithreading/ encryption

问题描述

我是Java的新手，它尝试使用Cipher和SecretKey加密和解密两条文本消息，如下面的代码bellow（第241行的代码）所示。 每当我尝试Decrypt此加密消息时，都会收到一条错误消息：
javax.crypto.BadPaddingException: Given final block not properly padded javax.crypto.IllegalBlockSizeException: Input length must be multiple of 8 when decrypting with padded cipher
我在这段代码中使用了3个线程和两个分别称为q1和q2的缓冲区/队列。 首先，我将消息放入缓冲区/队列中。 然后，在下一个类中，我检索该消息并将其加密，然后发送到下一个类。 然后，该类将再次将其放入缓冲区/队列。 最后，在最后一个类中，它将从缓冲区中检索并解密。 这是发生问题的地方。 发生同步错误。 我已经尝试解决这个错误很多天了，没有运气。 其他在线文档也没有帮助。 如果您可以编辑此代码或通过示例向我展示，我将不胜感激 

import java.security.KeyPairGenerator;
import java.security.KeyPair;
import java.security.NoSuchAlgorithmException;
import java.security.PublicKey;
import java.security.PrivateKey;
import java.security.Signature;
import java.io.*;
import java.util.*;
import java.util.concurrent.TimeUnit;
import javax.crypto.Cipher;
import javax.crypto.KeyGenerator;
import javax.crypto.NoSuchPaddingException;
import javax.crypto.SecretKey;



class Q5 { //Queue/Buffer   
    byte[] shipmentConfirmation;//will include the actual message content been delivered
    boolean valueSet = false;
    synchronized byte[] get() 
    {       
        while(!valueSet) 
        try 
        {
            wait();
        } 
        catch(InterruptedException e) 
        {
            System.out.println("InterruptedException caught");
        }
        //System.out.println("Got: " + n);
        valueSet = false;
        notify();
        return shipmentConfirmation;
    }
    synchronized void put(byte[] shipmentCinfirm) 
    {
        while(valueSet)
        try 
        {
            wait();
        } 
        catch(InterruptedException e) 
        {
            System.out.println("InterruptedException caught");
        }
        this.shipmentConfirmation = shipmentCinfirm;
        valueSet = true;
        //System.out.println("Put: " + n);
        notify();
    }
}

class Global5{
    public static int sendcouter = 0;
    public static SecretKey secret_Key;
    public static Cipher desCipher;
}


//<<security pattern>> SymmetricEncryptionEncryptor
class SecurityEncryptor//<<security>> Encryptor
{
    static byte[] Encryptor(byte shipmentConfirmation[],Cipher c) throws Exception //Encryptor
    {       
        byte[] ciphertext = SecurityEncryptionAlgorithm.EncryptionAlgorithm(shipmentConfirmation,c,Global5.secret_Key);
        return ciphertext;
    }   
}
class SecurityEncryptionAlgorithm//<<security>> EncryptionAlgorithm
{
    static byte[] EncryptionAlgorithm(byte shipmentConfirmation[],Cipher c,SecretKey sk) throws Exception 
    {
        c.init(Cipher.ENCRYPT_MODE, sk);
        return c.doFinal(shipmentConfirmation);
    }
}



//<<security pattern>> aSecureAsynchronousMCReceiverConnector
class SecurityDecryptor//<<Security>> Decryptor
{
    static byte[] Decryptor(byte EncryptedShipmentConfirmation[],Cipher c,SecretKey sk) throws Exception //Decryptor
    {
        byte[] ct = SecurityDecryptionAlgorithm.DecryptionAlgorithm(EncryptedShipmentConfirmation,c,sk);
        return ct;
    }   
}
class SecurityDecryptionAlgorithm//<<Security>> DecryptionAlgorithm
{
    static byte[] DecryptionAlgorithm(byte EncryptedShipmentConfirmation[],Cipher c,SecretKey sk) throws Exception 
    {
        c.init(Cipher.DECRYPT_MODE, sk);
        return c.doFinal(EncryptedShipmentConfirmation);
    }
}



public class testFigure1 { //Main
       public static void main(String args[]) throws Exception {          
            Q5 q1 = new Q5();//creating buffer/queue
            Q5 q2 = new Q5();

            System.out.println("How many messages to send: ");
            Scanner in = new Scanner(System.in);
            int input = in.nextInt();//Get input from the supplier          

            aSupplierInterface Supplier = new aSupplierInterface(q1, input);    
            aSecuritySenderCoordinator SenderCoordinator = new aSecuritySenderCoordinator(q1, input, q2);           
            aSecurityReceiverCoordinator receive = new aSecurityReceiverCoordinator(q2, input);   
            Supplier.t_pro.join();
            SenderCoordinator.t_coordinator5.join();
            receive.t_SecurityReceiverCoordinator5.join();
            System.out.println("End of Program!");
       }   
}

class aSupplierInterface  implements Runnable //<<application Component>> aSupplierInterface
{
    Q5 q;   
    int supinput;
    Thread t_pro;//pro to represent producer or suppler
    aSupplierInterface(Q5 qq, int input)
    {
        supinput = input;
        this.q = qq;
        t_pro = new Thread(this, "Producer");
        t_pro.start();
    }
    public void run() 
    {
        int i = 0;
        String shipment;
        byte[] shipmentConfirmation;
        while(i<supinput)
        {
            i++;
            shipment = "This is the Delivery Number: "+ i;
            shipmentConfirmation = shipment.getBytes();

            q.put(shipmentConfirmation);//Putting supplier's goods in a queue/buffer            
        }   
    }       
}

class aSecuritySenderCoordinator implements Runnable //<<security coordinator>> aSecuritySenderCoordinator
{
    Q5 q;
    Q5 q2;
    Thread t_coordinator5;
    int supinput;

    public aSecuritySenderCoordinator(Q5 qq, int input, Q5 q2) throws Exception
    {       
        supinput=input;
        this.q = qq;    
        this.q2=q2;
        t_coordinator5 = new Thread(this, "coordinator5");
        t_coordinator5.start();
    }

    public void run() 
    {
        byte[] pkShipmentConfirmation;
        byte[] shipmentConfirmation;
        int i = 0;
        while(i<supinput) 
        {               
            i++;

                //Getting goods that supplier has put in the queue previously
            pkShipmentConfirmation=q.get();//This will contain content of the message/delivery you are sending
            KeyGenerator keygen;
            try {
            keygen = KeyGenerator.getInstance("DES");
            Global5.sendcouter++;//To Create the key once
            if(Global5.sendcouter==1)//Create once
            {
                Global5.secret_Key = keygen.generateKey();
                Global5.desCipher = Cipher.getInstance("DES/ECB/PKCS5Padding");
            }           
            //String st1 = new String(pkShipmentConfirmation);//just to print a message
            //System.out.println("*ORIGINAL MESSAGE:"+st1);    
            shipmentConfirmation = SecurityEncryptor.Encryptor(pkShipmentConfirmation,Global5.desCipher);//Encrypting 


            new anAsynchronousMCReceiver(q2, shipmentConfirmation);     

            } catch (NoSuchAlgorithmException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            } catch (Exception e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            }
        }
    }
}




class anAsynchronousMCReceiver 
{ //<<communication pattern>> anAsynchronousMCReceiver
       Q5 q;

       anAsynchronousMCReceiver( Q5 q2, byte[] shipmentConfirm) throws Exception
       {
           this.q = q2;
           q.put(shipmentConfirm);  //Entering received data in to the Queue/Buffer 
       }
}



class aSecurityReceiverCoordinator implements Runnable//<<security coordinator>> aSecurityReceiverCoordinator
{       
    Thread t_SecurityReceiverCoordinator5;  
    Q5 q;
    int supinput;
    byte[]encryptedShipmentConfirmation;
    public aSecurityReceiverCoordinator(Q5 q2, int input) throws Exception
    {  
        this.q = q2;    
        supinput = input;
        t_SecurityReceiverCoordinator5 = new Thread(this, "SecurityReceiverCoordinator5");
        t_SecurityReceiverCoordinator5.start();

    }
    public void run() 
    {
        try {
            int i = 0;
            while(i<supinput) 
            {           
                i++;
                encryptedShipmentConfirmation = q.get();                
                byte[] confirmation = SecurityDecryptor.Decryptor(encryptedShipmentConfirmation,Global5.desCipher,Global5.secret_Key);//ERROR HAPPENS HERE              
                String shipConfirmation = new String(confirmation);

                System.out.println("AT DelivertyOrder: " +  shipConfirmation);
            }
        } catch (Exception e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
    }
}

如果您复制并粘贴该程序，它将在您的计算机上运行

2 个解决方案

解决方案1
 2  2016-09-05 09:09:16

不用过多看代码，我可以看到它使用了Cipher的共享实例。 Cipher不是线程安全的，并且在SecurityDecryptionAlgorithm和SecurityEncryptionAlgorithm都使用了SecurityDecryptionAlgorithm ，因此它要求麻烦...而麻烦的是内部缓冲区已损坏并引发了所显示的异常。

要解决此问题，只需对每个加密/解密（首选解决方案）使用实例密码，为每个线程创建一个实例，或者使SecurityDecryptionAlgorithm和SecurityEncryptionAlgorithm的静态方法同步，并为每个实例提供不同的Cipher实例。

我将从Global5删除Cipher ，并在每次调用时实例化一个新的加密或解密对象。

为了使它更加可见，此代码调用 

c.init(Cipher.ENCRYPT_MODE, sk);

和 

c.init(Cipher.DECRYPT_MODE, sk);

在同一情况下...我确信它会使密码更加混乱。

解决方案2
 2 已采纳  2016-09-05 18:07:44

多线程问题：

如果要使用相同的Cipher对象实例进行加密或解密，则必须特别小心， 尤其是当有多个线程访问同一Cipher对象（在您的情况下）时，因为它内部使用了缓冲区，填充等，因此即使您可以指定适当的填充方案，就像您指定PKCS5Padding或者您不指定任何填充（使用AES/ECB/NoPadding或使用ECB模式DES/ECB/PKCS5Padding ）， 则很可能会遇到异常DES/ECB/PKCS5Padding javax.crypto.BadPaddingException: Given final block not properly padded并且javax.crypto.IllegalBlockSizeException: Input length must be multiple of 8 when decrypting with padded cipher因为内部的Cipher对象被弄乱了。

现在，由于您使用的是相同的Cipher对象，因此即使您正确指定了padding等，但由于它是同一个对象，仍然会出现与padding相关的异常。

密码学问题：

如果将CBC模式用于Cipher对象，则还应该提供IvParameterSpec对象，否则您可能会遇到java.security.InvalidKeyException异常。

阅读此答案 。

另外，建议使用CBC模式而不是ECB模式。

阅读此答案。

更新的代码

因此，您的最终代码如下所示，它将毫无例外地运行，但是您指定的消息数与答案- How many messages to send:

PS：我已经清理了一些代码以关闭您的Scanner对象，等等，您也应该注意这些事情 

import java.security.NoSuchAlgorithmException;
import java.util.Scanner;

import javax.crypto.Cipher;
import javax.crypto.KeyGenerator;
import javax.crypto.SecretKey;
import javax.crypto.spec.IvParameterSpec;



class Q5 { //Queue/Buffer   
    byte[] shipmentConfirmation;//will include the actual message content been delivered
    boolean valueSet = false;
    synchronized byte[] get() 
    {       
        while(!valueSet) 
        try 
        {
            wait();
        } 
        catch(InterruptedException e) 
        {
            System.out.println("InterruptedException caught");
        }
        //System.out.println("Got: " + n);
        valueSet = false;
        notify();
        return shipmentConfirmation;
    }
    synchronized void put(byte[] shipmentCinfirm) 
    {
        while(valueSet)
        try 
        {
            wait();
        } 
        catch(InterruptedException e) 
        {
            System.out.println("InterruptedException caught");
        }
        this.shipmentConfirmation = shipmentCinfirm;
        valueSet = true;
        //System.out.println("Put: " + n);
        notify();
    }
}

class Global5{
    public static int sendcouter = 0;
    public static SecretKey secret_Key;
    public static Cipher desCipher;
}


//<<security pattern>> SymmetricEncryptionEncryptor
class SecurityEncryptor//<<security>> Encryptor
{
    static byte[] Encryptor(byte shipmentConfirmation[],Cipher c) throws Exception //Encryptor
    {       
        byte[] ciphertext = SecurityEncryptionAlgorithm.EncryptionAlgorithm(shipmentConfirmation,c,Global5.secret_Key);
        return ciphertext;
    }   
}
class SecurityEncryptionAlgorithm//<<security>> EncryptionAlgorithm
{
    static byte[] EncryptionAlgorithm(byte shipmentConfirmation[],Cipher c,SecretKey sk) throws Exception 
    {
        byte[] iv = {0, 0, 0, 0, 0, 0, 0, 0};
        IvParameterSpec ivspec = new IvParameterSpec(iv);
        c.init(Cipher.ENCRYPT_MODE, sk, ivspec);
        return c.doFinal(shipmentConfirmation);
    }
}



//<<security pattern>> aSecureAsynchronousMCReceiverConnector
class SecurityDecryptor//<<Security>> Decryptor
{
    static byte[] Decryptor(byte EncryptedShipmentConfirmation[],Cipher c,SecretKey sk) throws Exception //Decryptor
    {
        byte[] ct = SecurityDecryptionAlgorithm.DecryptionAlgorithm(EncryptedShipmentConfirmation,c,sk);
        return ct;
    }   
}
class SecurityDecryptionAlgorithm//<<Security>> DecryptionAlgorithm
{
    static byte[] DecryptionAlgorithm(byte EncryptedShipmentConfirmation[],Cipher c,SecretKey sk) throws Exception 
    {
        byte[] iv = {0, 0, 0, 0, 0, 0, 0, 0};
        IvParameterSpec ivspec = new IvParameterSpec(iv);
        c.init(Cipher.DECRYPT_MODE, sk, ivspec);
        return c.doFinal(EncryptedShipmentConfirmation);
    }
}



public class testFigure1 { //Main
       public static void main(String args[]) throws Exception {          
            Q5 q1 = new Q5();//creating buffer/queue
            Q5 q2 = new Q5();

            System.out.println("How many messages to send: ");
            Scanner in = new Scanner(System.in);
            int input = in.nextInt();//Get input from the supplier          
            in.close();

            aSupplierInterface Supplier = new aSupplierInterface(q1, input);    
            aSecuritySenderCoordinator SenderCoordinator = new aSecuritySenderCoordinator(q1, input, q2);           
            aSecurityReceiverCoordinator receive = new aSecurityReceiverCoordinator(q2, input);   
            Supplier.t_pro.join();
            SenderCoordinator.t_coordinator5.join();
            receive.t_SecurityReceiverCoordinator5.join();
            System.out.println("End of Program!");
       }   
}

class aSupplierInterface  implements Runnable //<<application Component>> aSupplierInterface
{
    Q5 q;   
    int supinput;
    Thread t_pro;//pro to represent producer or suppler
    aSupplierInterface(Q5 qq, int input)
    {
        supinput = input;
        this.q = qq;
        t_pro = new Thread(this, "Producer");
        t_pro.start();
    }
    public void run() 
    {
        int i = 0;
        String shipment;
        byte[] shipmentConfirmation;
        while(i<supinput)
        {
            i++;
            shipment = "This is the Delivery Number: "+ i;
            shipmentConfirmation = shipment.getBytes();

            q.put(shipmentConfirmation);//Putting supplier's goods in a queue/buffer            
        }   
    }       
}

class aSecuritySenderCoordinator implements Runnable //<<security coordinator>> aSecuritySenderCoordinator
{
    Q5 q;
    Q5 q2;
    Thread t_coordinator5;
    int supinput;

    public aSecuritySenderCoordinator(Q5 qq, int input, Q5 q2) throws Exception
    {       
        supinput=input;
        this.q = qq;    
        this.q2=q2;
        t_coordinator5 = new Thread(this, "coordinator5");
        t_coordinator5.start();
    }

    public void run() 
    {
        byte[] pkShipmentConfirmation;
        byte[] shipmentConfirmation;
        int i = 0;
        while(i<supinput) 
        {               
            i++;

                //Getting goods that supplier has put in the queue previously
            pkShipmentConfirmation=q.get();//This will contain content of the message/delivery you are sending
            KeyGenerator keygen;
            try {
            keygen = KeyGenerator.getInstance("DES");
            Global5.sendcouter++;//To Create the key once
            if(Global5.sendcouter==1)//Create once
            {
                Global5.secret_Key = keygen.generateKey();
                Global5.desCipher = Cipher.getInstance("DES/CBC/PKCS5Padding");
            }           
            //String st1 = new String(pkShipmentConfirmation);//just to print a message
            //System.out.println("*ORIGINAL MESSAGE:"+st1);    
            shipmentConfirmation = SecurityEncryptor.Encryptor(pkShipmentConfirmation,Cipher.getInstance("DES/CBC/PKCS5Padding"));//Encrypting 


            new anAsynchronousMCReceiver(q2, shipmentConfirmation);     

            } catch (NoSuchAlgorithmException e) {
                e.printStackTrace();
            } catch (Exception e) {
                e.printStackTrace();
            }
        }
    }
}




class anAsynchronousMCReceiver 
{ //<<communication pattern>> anAsynchronousMCReceiver
       Q5 q;

       anAsynchronousMCReceiver( Q5 q2, byte[] shipmentConfirm) throws Exception
       {
           this.q = q2;
           q.put(shipmentConfirm);  //Entering received data in to the Queue/Buffer 
       }
}



class aSecurityReceiverCoordinator implements Runnable//<<security coordinator>> aSecurityReceiverCoordinator
{       
    Thread t_SecurityReceiverCoordinator5;  
    Q5 q;
    int supinput;
    byte[]encryptedShipmentConfirmation;
    public aSecurityReceiverCoordinator(Q5 q2, int input) throws Exception
    {  
        this.q = q2;    
        supinput = input;
        t_SecurityReceiverCoordinator5 = new Thread(this, "SecurityReceiverCoordinator5");
        t_SecurityReceiverCoordinator5.start();

    }
    public void run() 
    {
        try {
            int i = 0;
            while(i<supinput) 
            {           
                i++;
                encryptedShipmentConfirmation = q.get();                
                byte[] confirmation = SecurityDecryptor.Decryptor(encryptedShipmentConfirmation,Cipher.getInstance("DES/CBC/PKCS5Padding"),Global5.secret_Key);//ERROR HAPPENS HERE              
                String shipConfirmation = new String(confirmation);

                System.out.println("AT DelivertyOrder: " +  shipConfirmation);
            }
        } catch (Exception e) {
            e.printStackTrace();
        }
    }
}

暂无
暂无

声明:本站的技术帖子网页，遵循CC BY-SA 4.0协议，如果您需要转载，请注明本站网址或者原文地址。任何问题请咨询:yoyou2525@163.com.

相关问题 Android Java AES加密密码填充和模式错误 Java密码 - AES填充问题 java中的密码填充字符串是什么？ 使用 python 解密 java（DESede/ECB/PKCS5Padding）密码 错误在哪里（和什么）-Java cipher Java密码和php mcrypt_encrypt（带有ECB填充的BLOWFISH算法） 用Java创建凯撒密码程序时出错 Java填充错误中的AES解密 在使用带有“AES/CBC/PKCS5Padding”的 Java 密码进行解密时，是否必须指定 IV？ 并且只能使用 SecretKeyFactory 吗？ 如何修复错误异常Java：错误cryptoAES无法初始化密码？
相关标签
 
粤ICP备18138465号  © 2020-2024 STACKOOM.COM