java - 解密压缩字符串

Question

我正在尝试解密此证书。因为它很大，所以我在加密之前先对其进行压缩。为了解密，我先解密然后解压它。我真的很感激任何帮助。

这是输出:

[B@3ac42916

[B@5cad8086while the output should be the certification string

package test11;
import java.security.KeyPair;
import java.security.KeyPairGenerator;
import java.security.NoSuchAlgorithmException;
import java.security.PrivateKey;
import java.security.PublicKey;

import javax.crypto.Cipher;

public class Sample {

public static void main(String [] args) throws Exception {
    // generate public and private keys
    KeyPair keyPair = buildKeyPair();
    PublicKey pubKey = keyPair.getPublic();
    PrivateKey privateKey = keyPair.getPrivate();
    
    
    GzipUtil zipp = new GzipUtil();
    // encrypt the message
    String hour = "00";
    String certificate="1"+","+"0336"+","+"RSA"+","+"CA 1552"+","+hour+","+pubKey+","+"RSA";
    byte [] cert = GzipUtil.zip(certificate) ;
    byte [] encrypted = encrypt(privateKey, cert.toString());     
    System.out.println(encrypted);  // <<encrypted message>>
    
    // decrypt the message
    byte[] secret = decrypt(pubKey, encrypted);
  String text= GzipUtil.unzip(secret);
    System.out.println(text);     // This is a secret message
}

public static KeyPair buildKeyPair() throws NoSuchAlgorithmException {
    final int keySize = 2048;
    KeyPairGenerator keyPairGenerator = KeyPairGenerator.getInstance("RSA");
    keyPairGenerator.initialize(keySize);      
    return keyPairGenerator.genKeyPair();
}

public static byte[] encrypt(PrivateKey privateKey, String message) throws Exception {
    Cipher cipher = Cipher.getInstance("RSA");  
    cipher.init(Cipher.ENCRYPT_MODE, privateKey);  

    return cipher.doFinal(message.getBytes());  
}

public static byte[] decrypt(PublicKey publicKey, byte [] encrypted) throws Exception {
    Cipher cipher = Cipher.getInstance("RSA");  
    cipher.init(Cipher.DECRYPT_MODE, publicKey);
    
    return cipher.doFinal(encrypted);
}
}

Answer 1

问题是您不应该使用 toString() 直接将字节数组转换为字符串。

第一个错误是System.out.println(encrypted);，第二个错误是cert.toString()，两者都使用.toString() 来自 Object，它返回一个无意义的字符串。

Object.toString()的JavaDoc

The toString method for class Object returns a string consisting of the name of the class of which the object is an instance, the at-sign character `@', and the unsigned hexadecimal representation of the hash code of the object. In other words, this method returns a string equal to the value of:

getClass().getName() + '@' + Integer.toHexString(hashCode())

当你想要显示字节数组的内容时，最好使用

System.out.println(Arrays.toString(encrypted));

此外，我会将加密更改为

public static byte[] encrypt(PrivateKey privateKey, byte[] message) throws Exception {
    Cipher cipher = Cipher.getInstance("RSA");  
    cipher.init(Cipher.ENCRYPT_MODE, privateKey);  

    return cipher.doFinal(message);  
}

并使用

byte [] encrypted = encrypt(privateKey, cert);