前端 JS 使用 RAS 加密密码，后端 Java 解密（适配 JDK6）

首先，需要安装 Java Cryptography Extension (JCE) Unlimited Strength Jurisdiction Policy Files，以支持 AES-256 加解密。

前端 JS 加密密码：

// 密码明文
var password = '123456';

// 生成随机盐值
var salt = CryptoJS.lib.WordArray.random(16);

// 生成密钥
var key = CryptoJS.PBKDF2(password, salt, {
  keySize: 256 / 32,
  iterations: 1000
});

// 生成向量
var iv = CryptoJS.lib.WordArray.random(16);

// 加密
var ciphertext = CryptoJS.AES.encrypt('hello world', key, {
  iv: iv,
  padding: CryptoJS.pad.Pkcs7,
  mode: CryptoJS.mode.CBC
});

// 生成加密结果
var result = {
  salt: CryptoJS.enc.Hex.stringify(salt),
  iv: CryptoJS.enc.Hex.stringify(iv),
  ciphertext: ciphertext.toString()
};

// 发送加密结果到后端
console.log(result);

后端解密：

import javax.crypto.Cipher;
import javax.crypto.SecretKey;
import javax.crypto.SecretKeyFactory;
import javax.crypto.spec.IvParameterSpec;
import javax.crypto.spec.PBEKeySpec;
import javax.crypto.spec.SecretKeySpec;
import java.security.spec.KeySpec;

public class AESUtil {
    public static String decrypt(String ciphertext, String salt, String iv, String password) {
        try {
            byte[] ciphertextBytes = hexStringToByteArray(ciphertext);
            byte[] saltBytes = hexStringToByteArray(salt);
            byte[] ivBytes = hexStringToByteArray(iv);

            // 生成密钥
            KeySpec keySpec = new PBEKeySpec(password.toCharArray(), saltBytes, 1000, 256);
            SecretKeyFactory secretKeyFactory = SecretKeyFactory.getInstance("PBKDF2WithHmacSHA1");
            byte[] keyBytes = secretKeyFactory.generateSecret(keySpec).getEncoded();
            SecretKey key = new SecretKeySpec(keyBytes, "AES");

            // 解密
            Cipher cipher = Cipher.getInstance("AES/CBC/PKCS5Padding");
            IvParameterSpec ivParameterSpec = new IvParameterSpec(ivBytes);
            cipher.init(Cipher.DECRYPT_MODE, key, ivParameterSpec);
            byte[] plaintextBytes = cipher.doFinal(ciphertextBytes);

            return new String(plaintextBytes, "UTF-8");
        } catch (Exception e) {
            e.printStackTrace();
            return null;
        }
    }

    private static byte[] hexStringToByteArray(String hexString) {
        int length = hexString.length();
        byte[] bytes = new byte[length / 2];
        for (int i = 0; i < length; i += 2) {
            bytes[i / 2] = (byte) ((Character.digit(hexString.charAt(i), 16) << 4)
                    + Character.digit(hexString.charAt(i+1), 16));
        }
        return bytes;
    }
}

使用方式：

String ciphertext = "U2FsdGVkX19wvXzj1q+L3f88Z3C8L4/pQDkGqJv0kBk=";
String salt = "a5c8d545b1dbd1f6a0ef4d7f5e1d61c6";
String iv = "a7ac9b3b9c13e3f9a09efdb2e3d3e0f7";
String password = "123456";

String plaintext = AESUtil.decrypt(ciphertext, salt, iv, password);
System.out.println(plaintext);