Decrypt locked configuration from Wenz VPN for Android.

WenzVPNDecrypt.java

import java.util.Map;
import java.util.HashMap;
import java.util.Base64;
import java.util.Map.Entry;
import javax.crypto.Cipher;
import javax.crypto.SecretKey;
import java.io.FileInputStream;
import java.io.ObjectInputStream;
import javax.crypto.spec.PBEKeySpec;
import javax.crypto.SecretKeyFactory;
import javax.crypto.spec.PBEParameterSpec;

public class WenzVPNDecrypt {
    public static String decrypt(String data) throws Exception {
        char[] key = "FH238924HCKWEHC3R239RCH47RY7RYCQ8X82X91298XYFH74R".toCharArray();

        Cipher cipher = Cipher.getInstance("PBEWithMD5AndDES");
        SecretKey secret = SecretKeyFactory.getInstance("PBEWithMD5AndDES").generateSecret(new PBEKeySpec(key));
        cipher.init(2, secret, new PBEParameterSpec("WENZ VPN".getBytes(), 20));
        return new String(cipher.doFinal(Base64.getDecoder().decode(data)), "utf-8");
    }

    public static void main(String[] args) throws Exception {
        if (args.length < 1) {
            System.err.println("ERROR: Missing file...");
            System.exit(0);
            return;
        }

        FileInputStream fis = new FileInputStream(args[0]);
        ObjectInputStream ois = new ObjectInputStream(fis);

        Map<String, String> cfg = (HashMap) ois.readObject();
        if (cfg.containsKey("303")) {
            cfg.remove("303");
        }

        for (Entry<String, String> entry: cfg.entrySet()) {
            System.out.println(decrypt(entry.getKey()) + " = " + decrypt(entry.getValue()));
        }
    }
}