AES加密 flutter java后台用的 AES/CBC/PKCS5Padding

可测试AES是否正确的网址

https://www.toolhelper.cn/SymmetricEncryption/AES

java后台代码如下

public static String encrypt(String clearText, String key, String iv) {
        byte[] result = null;
        try {
            byte[] key_bytes = toByte(MD5Util.getMD5String(MD5Util.getMD5String(key)));
            result = encrypt(clearText.getBytes(), key_bytes, iv);
        } catch (Exception e) {
            e.printStackTrace();
        }
        return toHex(result);
    }




    private static byte[] encrypt(byte[] clear, byte[] raw, String iv) throws Exception {
        SecretKeySpec skeySpec = new SecretKeySpec(raw, "AES");
        Cipher cipher = Cipher.getInstance("AES/CBC/PKCS5Padding");
        cipher.init(Cipher.ENCRYPT_MODE, skeySpec, new IvParameterSpec(iv.getBytes()));
        byte[] encrypted = cipher.doFinal(clear);
        return encrypted;
    }

    public static byte[] toByte(String hexString) {
        int len = hexString.length() / 2;
        byte[] result = new byte[len];
        for (int i = 0; i < len; i++) {
            result[i] = Integer.valueOf(hexString.substring(2 * i, 2 * i + 2), 16).byteValue();
        }
        return result;
    }

    private static String toHex(byte[] buf) {
        if (buf == null)
            return "";
        StringBuffer result = new StringBuffer(2 * buf.length);
        for (int i = 0; i < buf.length; i++) {
            appendHex(result, buf[i]);
        }
        return result.toString();
    }

测试用例

clearText = test123456    key = 1691645969   iv = a0fe7c7c98e09e8c   最后aes后 30f3084aae678924002f6f0c41e77784

加密文本 test123456，java后台对 key时间戳 1691645969， MD5了两次，然后进行AES。AES的iv是  a0fe7c7c98e09e8c

切记 java 后台 AES/CBC/PKCS5Padding，PKCS5 和 PKCS7 是一样的。其他平台测试时可以用 PKCS7.

flutter 用的三方库 

  encrypt: ^5.0.1 #AES
  crypto: ^3.0.3 #MD5

导入头文件

import 'package:encrypt/encrypt.dart' as ce;
import 'package:crypto/crypto.dart';

代码

    DateTime today = DateTime.now();
    int date1 = today.millisecondsSinceEpoch;
    print('当前时间戳：$date1');
    var nonce = '$date1';
    nonce = '1691645969';
    print('nonce：$nonce');
    var key = md5Crypto(md5Crypto(nonce));
    print('key：$key');
    var pwdCryptStr = aesEncrypted('test123456', key, 'a0fe7c7c98e09e8c');
    print(pwdCryptStr);

开始 key 和 iv 都用的 fromUtf8，和后台生成的总是不一致，总以为是 mode 的问题。幸亏那测试网址了，可以一个个测试结果。

  String aesEncrypted(String str, String aesKey, String ivStr){
    final key = ce.Key.fromBase16(aesKey);
    final iv = ce.IV.fromUtf8(ivStr);
    final encrypter = ce.Encrypter(ce.AES(key, mode: ce.AESMode.cbc));
    final encrypted = encrypter.encrypt(str,iv: iv);
    return encrypted.base16.toLowerCase();
  }