Java AES 128 ECB 到 AES 256 ECB 轉換

Question

我在 ECB 模式下將 AES 128 位加密升級到 AES 256 時遇到問題。 但我無法找到任何解決方案。 大多數解決方案都適用於 AES 256 CBC 模式。 非常感謝任何幫助。

我得到的例外是由於填充錯誤

PS：我知道 AES 中 ECB 模式的漏洞，但這是我目前需要實現的。

import org.apache.tomcat.util.codec.binary.Base64;

import javax.crypto.Cipher;
import javax.crypto.spec.SecretKeySpec;
import java.security.GeneralSecurityException;

public class Decrypt {
    public static String decryptPayload(String payload) throws Exception {
        byte[] keyBytes = {
                0x74, 0x68, 0x69, 0x73, 0x49, 0x73, 0x43, 0x53, 0x75, 0x63, 0x72, 0x65, 0x44, 0x4b, 0x55, 0x79
        };
        try {
            payload = payload.replace(' ', '+');
            Cipher cipher = Cipher.getInstance("AES/ECB/PKCS5PADDING");
            final SecretKeySpec secretKey = new SecretKeySpec(keyBytes, "AES");
            cipher.init(Cipher.DECRYPT_MODE, secretKey);
            return new String(cipher.doFinal(
                    Base64.decodeBase64(payload)));
        } catch (GeneralSecurityException e) {
            e.printStackTrace();
        }
        return null;
    }
}

我嘗試的 AES 256 ECB 的實現如下：

    public static String decrypt(String strToDecrypt, String secretKey) {
        try
        {
            IvParameterSpec ivspec = new IvParameterSpec(iv);

            SecretKeyFactory factory = SecretKeyFactory.getInstance("PBKDF2WithHmacSHA256");
            KeySpec spec = new PBEKeySpec(secretKey.toCharArray(), salt.getBytes(), 65536, 256);
            SecretKey tmp = factory.generateSecret(spec);
            SecretKeySpec secretKey = new SecretKeySpec(tmp.getEncoded(), "AES");

            Cipher cipher = Cipher.getInstance("AES/ECB/PKCS5PADDING");
            cipher.init(Cipher.DECRYPT_MODE, secretKey, ivspec);
            return new String(cipher.doFinal(Base64.getDecoder().decode(strToDecrypt)));
        }
        catch (Exception e) {
            System.out.println("Error while decrypting: " + e.toString());
        }
        return null;
    }

Answer 1

感謝@MichaelFehr，對我有用的整個解決方案

public void tester() {
        System.out.println("Program starts");
        String key = "5u7x!A%D*G-KaPdSgVkYp3s6v9y/B?E(";
        String payload = "Test string to test AES 256 ECB";
        String encrypted = "";
        String decrypted = "";
        // Encryption
        try{
            Cipher cipher = Cipher.getInstance("AES/ECB/PKCS5Padding");
            final SecretKeySpec secretKey = new SecretKeySpec(key.getBytes(), "AES");
            cipher.init(Cipher.ENCRYPT_MODE, secretKey);
            final String encryptedString = Base64.encodeBase64String(cipher.doFinal(payload.getBytes()));
            System.out.println("The encrypted string is\n"+encryptedString);
            encrypted = encryptedString;
        }
        catch(Exception e){
            e.printStackTrace();
        }


        // Decryption
        try
        {
            decrypted = encrypted.replace(' ', '+');
            Cipher cipher = Cipher.getInstance("AES/ECB/PKCS5PADDING");
            final SecretKeySpec secretKey = new SecretKeySpec(key.getBytes(), "AES");
            cipher.init(Cipher.DECRYPT_MODE, secretKey);
            final String decryptedString = new String(cipher.doFinal(Base64.decodeBase64(encrypted)));
            System.out.println("The decrypted string is\n"+decryptedString);
            decrypted=decryptedString;
        }
        catch (Exception e)
        {
            e.printStackTrace();
        }
    }