AES加密错误:javax.crypto.BadPaddingException

Question

此代码出现以下错误：javax.crypto.BadPaddingException：给定的最后一个块没有正确填充。我指出了程序中出现错误的地方。

package aes;
import javax.crypto.*;
import java.security.*;
import javax.crypto.spec.SecretKeySpec;
import sun.misc.*;

public class AESencrpytion {
  //private static final byte[] keyValue = new byte[]{'S','e','c','r','e','t'};

  public static String encrypt(String data) throws Exception{
    KeyGenerator keyGen = KeyGenerator.getInstance("AES");
    SecureRandom rand = new SecureRandom();
    keyGen.init(rand);
    Key key = keyGen.generateKey();
    Cipher cipher = Cipher.getInstance("AES");
    cipher.init(Cipher.ENCRYPT_MODE, key);
    byte[] encValue = cipher.doFinal(data.getBytes());
    String encryptedValue = new BASE64Encoder().encode(encValue);
    return encryptedValue;
  }
  public static String decrypt(String encData) throws Exception {
    KeyGenerator keyGen = KeyGenerator.getInstance("AES");
    SecureRandom rand = new SecureRandom();
    keyGen.init(rand);
    Key key = keyGen.generateKey();
    Cipher cipher = Cipher.getInstance("AES");
    cipher.init(Cipher.DECRYPT_MODE, key);
    byte[] decodedValue = new BASE64Decoder().decodeBuffer(encData);
    //ERROR HAPPENS HERE
    byte[] decValue = cipher.doFinal(decodedValue);
    String decryptedVal = new String(decValue);
    return decryptedVal;
  }

主要类别：

package aes;
public class AEStest {
  public static void main(String[] args) throws Exception {
    String password = "mypassword";
    String passwordEnc = AESencrpytion.encrypt(password);
    String passwordDec = AESencrpytion.decrypt(passwordEnc);
    System.out.println("Plain Text : " + password);
    System.out.println("Encrypted Text : " + passwordEnc);
    System.out.println("Decrypted Text : " + passwordDec);
  }
}

我是AES和加密的新手，这是一项家庭作业。谢谢你的帮助！我很感激。

Answer 1

在加密和解密过程中使用不同的密钥，因为这两种方法都是随机生成的。您必须使用相同的键。

将init方法添加到类中以生成一次密钥，或者在类外生成密钥并将其传递到两个方法中。