ez_baby_apk

ez_baby_apk

主方法

protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(C0096R.layout.activity_main);
        final String key1 = "reversecarefully".replaceAll("e", "3");//将e换成3
        this.flag = (TextView) findViewById(C0096R.C0099id.flag);
        final String vector2 = (String) confusion("reversehavemagic");//对字符串进行md5加密
        this.input_1 = (EditText) findViewById(C0096R.C0099id.input_1);
        Button button = (Button) findViewById(C0096R.C0099id.button);
        this.button = button;
        button.setOnClickListener(new C00001(this, vector2, key1, "BxLHc1KruiH31I94W171oal+9olDzgBIjnK/J1Db0IUyi+MbI38+nw62ejCPShRB"));//此处为密文
    }//注意其传参位置 vector才是key，key是偏移量

md5加密方法(此处输出的是32位小写)

public static Object confusion(String str) {
        MessageDigest md = MessageDigest.getInstance("MD5");     // Catch: Exception -> L6
        md.update(str.getBytes());     // Catch: Exception -> L6
        return new BigInteger(1, md.digest()).toString(16);
    L6:
        e = move-exception;
        e.printStackTrace();
        return null;
    }

DES加密方法

public DES() {
    }

    public static String encrypt(String strKey, String strClearText, String mstrIvParameter) {
        byte[] raw = strKey.getBytes();     // Catch: Exception -> L7
        SecretKeySpec skeySpec = new SecretKeySpec(raw, type);     // Catch: Exception -> L7
        Cipher cipher = Cipher.getInstance(CBC_PKCS5_PADDING);     // Catch: Exception -> L7
        IvParameterSpec iv = new IvParameterSpec(mstrIvParameter.getBytes());     // Catch: Exception -> L7
        cipher.init(1, skeySpec, iv);     // Catch: Exception -> L7
        byte[] cipherText = cipher.doFinal(strClearText.getBytes());     // Catch: Exception -> L7
        String strBase64Content = Base64.encodeToString(cipherText, 0);     // Catch: Exception -> L7
        return strBase64Content.replaceAll(System.getProperty("line.separator"), "");
    L7:
        e = move-exception;
        e.printStackTrace();
        return null;
    }

此处des使用的是CBC模式，pkcs5padding带有偏移量

密文"BxLHc1KruiH31I94W171oal+9olDzgBIjnK/J1Db0IUyi+MbI38+nw62ejCPShRB"

密码(String) confusion("reversehavemagic") 32位小写md5

偏移"reversecarefully".replaceAll("e", "3")

但我自己电脑复现出来是乱码，可以通过网上的解密工具进行解密

NKCTF{nI_k@i_sHi_zhu_j1an_il_Jie_RE_le}