解决cryptoJS.AES默认参数加密,java无法解密的问题

有时候我们需要跨编程语言进行加密加密。比如nodejs里面加密，java里面解密，或者反过来java加密，nodejs解密。node可以使用cryptojs，java可以使用javax.crypto.Cipher包。

网上有很多关于这方面的文章。然而如果node使用了默认的参数进行加密（比如现有业务已经生成了一些已经加密的数据），需要java进行解密，这时候按照默认的方法就无法正常解密了。一般的aes加密使用的是16位的key，而cryptojs默认的key可以任意长度。

cryptoJS.AES默认参数加密代码：

const cryptoJS = require("crypto-js");
const encryptedValue = cryptoJS.AES.encrypt(value, secret).toString()

对应的java解密的示例代码：

 try {
            byte[] cipherData = cn.hutool.core.codec.Base64.decode(encryptedText);
            byte[] saltData = Arrays.copyOfRange(cipherData, 8, 16);
            MessageDigest md5 = MessageDigest.getInstance("MD5");
            final byte[][] keyAndIV = GenerateKeyAndIV(32, 16, 1, saltData, secret.getBytes(StandardCharsets.UTF_8), md5);
            SecretKeySpec key = new SecretKeySpec(keyAndIV[0], "AES");
            IvParameterSpec iv = new IvParameterSpec(keyAndIV[1]);
            byte[] encrypted = Arrays.copyOfRange(cipherData, 16, cipherData.length);
            Cipher aesCBC = Cipher.getInstance("AES/CBC/PKCS5Padding");
            aesCBC.init(Cipher.DECRYPT_MODE, key, iv);
            byte[] decryptedData = aesCBC.doFinal(encrypted);
            return new String(decryptedData, StandardCharsets.UTF_8);
        } catch (Exception e) {
            //log.error("aesDecrypt error.param={}", encryptedText, e);
            return null;
        }

以上代码来自参考自：https://www.pianshen.com/question/31931314701/

上面只是演示了如何进行node加密，java解密；而java默认加密的值，node也是无法解密的，需要采用以下写法。

java加密示例代码

 try {
            byte[] input = datastr.getBytes();
            // 以下两个变量不可修改，否则java加密的，node无法解密
            byte[] saltData = "DFބf$t:".getBytes();
            byte[] preData = "Salted__".getBytes();
            MessageDigest md5 = MessageDigest.getInstance("MD5");
            final byte[][] keyAndIV = GenerateKeyAndIV(32, 16, 1, saltData, secret.getBytes(StandardCharsets.UTF_8), md5);
            SecretKeySpec key = new SecretKeySpec(keyAndIV[0], "AES");
            IvParameterSpec iv = new IvParameterSpec(keyAndIV[1]);
            Cipher aesCBC = Cipher.getInstance("AES/CBC/PKCS5Padding");
            aesCBC.init(Cipher.ENCRYPT_MODE, key, iv);
            byte[] encrypt = aesCBC.doFinal(input);
            byte[] encryptedData = addBytes(saltData, encrypt);
            return cn.hutool.core.codec.Base64.encode(addBytes(preData, encryptedData));
        } catch (Exception e) {
            log.error("aesEncrypt error.param={}", datastr, e);
            return null;
        }

上述代码亲测有效，使用前可以自己测试测试

对应的node解密示例代码

const cryptoJS = require("crypto-js");
let decryptedValue = cryptoJS.AES.decrypt(value, secret).toString(cryptoJS.enc.Utf8);

完整代码示例

import lombok.extern.slf4j.Slf4j;
import javax.crypto.Cipher;
import javax.crypto.spec.IvParameterSpec;
import javax.crypto.spec.SecretKeySpec;
import java.nio.charset.StandardCharsets;
import java.security.DigestException;
import java.security.MessageDigest;
import java.util.Arrays;
/**
 *
 * 兼容node
 *
 */
@Slf4j
public class AESUtils {
    public static String aesEncrypt(String datastr, String secret) {
        try {
            byte[] input = datastr.getBytes();
            // 以下两个变量不可修改，否则java加密的，node无法解密
            byte[] saltData = "DFބf$t:".getBytes();
            byte[] preData = "Salted__".getBytes();
            MessageDigest md5 = MessageDigest.getInstance("MD5");
            final byte[][] keyAndIV = GenerateKeyAndIV(32, 16, 1, saltData, secret.getBytes(StandardCharsets.UTF_8), md5);
            SecretKeySpec key = new SecretKeySpec(keyAndIV[0], "AES");
            IvParameterSpec iv = new IvParameterSpec(keyAndIV[1]);
            Cipher aesCBC = Cipher.getInstance("AES/CBC/PKCS5Padding");
            aesCBC.init(Cipher.ENCRYPT_MODE, key, iv);
            byte[] encrypt = aesCBC.doFinal(input);
            byte[] encryptedData = addBytes(saltData, encrypt);
            return cn.hutool.core.codec.Base64.encode(addBytes(preData, encryptedData));
        } catch (Exception e) {
            log.error("aesEncrypt error.param={}", datastr, e);
            return null;
        }
    }
    public static String aesDecrypt(String encryptedText, String secret){
        // 参考文章：https://www.pianshen.com/question/31931314701/
        try {
            byte[] cipherData = cn.hutool.core.codec.Base64.decode(encryptedText);
            byte[] saltData = Arrays.copyOfRange(cipherData, 8, 16);
            MessageDigest md5 = MessageDigest.getInstance("MD5");
            final byte[][] keyAndIV = GenerateKeyAndIV(32, 16, 1, saltData, secret.getBytes(StandardCharsets.UTF_8), md5);
            SecretKeySpec key = new SecretKeySpec(keyAndIV[0], "AES");
            IvParameterSpec iv = new IvParameterSpec(keyAndIV[1]);
            byte[] encrypted = Arrays.copyOfRange(cipherData, 16, cipherData.length);
            Cipher aesCBC = Cipher.getInstance("AES/CBC/PKCS5Padding");
            aesCBC.init(Cipher.DECRYPT_MODE, key, iv);
            byte[] decryptedData = aesCBC.doFinal(encrypted);
            return new String(decryptedData, StandardCharsets.UTF_8);
        } catch (Exception e) {
            log.error("aesDecrypt error.param={}", encryptedText, e);
            return null;
        }
    }
    public static byte[][] GenerateKeyAndIV(int keyLength, int ivLength, int iterations, byte[] salt, byte[] password, MessageDigest md) {
        int digestLength = md.getDigestLength();
        int requiredLength = (keyLength + ivLength + digestLength - 1) / digestLength * digestLength;
        byte[] generatedData = new byte[requiredLength];
        int generatedLength = 0;
        try {
            md.reset();
// Repeat process until sufficient data has been generated
            while (generatedLength < keyLength + ivLength) {
// Digest data (last digest if available, password data, salt if available)
                if (generatedLength > 0)
                    md.update(generatedData, generatedLength - digestLength, digestLength);
                md.update(password);
                if (salt != null)
                    md.update(salt, 0, 8);
                md.digest(generatedData, generatedLength, digestLength);
// additional rounds
                for (int i = 1; i < iterations; i++) {
                    md.update(generatedData, generatedLength, digestLength);
                    md.digest(generatedData, generatedLength, digestLength);
                }
                generatedLength += digestLength;
            }
// Copy key and IV into separate byte arrays
            byte[][] result = new byte[2][];
            result[0] = Arrays.copyOfRange(generatedData, 0, keyLength);
            if (ivLength > 0)
                result[1] = Arrays.copyOfRange(generatedData, keyLength, keyLength + ivLength);
            return result;
        } catch (DigestException e) {
            throw new RuntimeException(e);
        } finally {
// Clean out temporary data
            Arrays.fill(generatedData, (byte)0);
        }
    }
    public static byte[] addBytes(byte[] data1, byte[] data2) {
        byte[] data3 = new byte[data1.length + data2.length];
        System.arraycopy(data1, 0, data3, 0, data1.length);
        System.arraycopy(data2, 0, data3, data1.length, data2.length);
        return data3;
    }
    public static void main(String[] args) {
        String secret = "aabbccddeeff";
        String datastr = "{\"m\":\"images\",\"u\":\"0\",\"t\":\"20230322\",\"f\":\"16794597950146230.png\"}";
        String t = aesEncrypt(datastr, secret);
        System.out.println(t);
        System.out.println(aesDecrypt(t, secret));
    }
}