SkyV1Keygen.java

/*
 * Copyright 2012 Rui Araújo, Luís Fonseca
 *
 * This file is part of Router Keygen.
 *
 * Router Keygen is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 * 
 * Router Keygen is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 * 
 * You should have received a copy of the GNU General Public License
 * along with Router Keygen.  If not, see <http://www.gnu.org/licenses/>.
 */
package org.exobel.routerkeygen.algorithms;

import android.os.Parcel;
import android.os.Parcelable;

import org.exobel.routerkeygen.R;

import java.security.MessageDigest;
import java.security.NoSuchAlgorithmException;
import java.util.List;


/*
 * This is the algorithm to generate the WPA passphrase 
 * for the SKYv1.
 * Generate the md5 hash form the mac.
 * Use the numbers in the following positions on the hash.
 *  Position 3,7,11,15,19,23,27,31 ,
 *  Use theses numbers, modulus 26, to find the correct letter
 *  and append to the key.
 */
public class SkyV1Keygen extends Keygen {

    public static final Parcelable.Creator<SkyV1Keygen> CREATOR = new Parcelable.Creator<SkyV1Keygen>() {
        public SkyV1Keygen createFromParcel(Parcel in) {
            return new SkyV1Keygen(in);
        }

        public SkyV1Keygen[] newArray(int size) {
            return new SkyV1Keygen[size];
        }
    };
    private final static String ALPHABET = "ABCDEFGHIJKLMNOPQRSTUVWXYZ";


    public SkyV1Keygen(String ssid, String mac) {
        super(ssid, mac);
    }

    private SkyV1Keygen(Parcel in) {
        super(in);
    }

    @Override
    public List<String> getKeys() {
        if (getMacAddress().length() != 12) {
            setErrorCode(R.string.msg_nomac);
            return null;
        }
        MessageDigest md;
        try {
            md = MessageDigest.getInstance("MD5");
        } catch (NoSuchAlgorithmException e1) {
            setErrorCode(R.string.msg_nomd5);
            return null;
        }
        md.reset();
        md.update(getMacAddress().getBytes());
        byte[] hash = md.digest();
        String key = "";
        for (int i = 1; i <= 15; i += 2) {
            int index = hash[i] & 0xFF;
            index %= 26;
            key += ALPHABET.substring(index, index + 1);
        }

        addPassword(key);
        return getResults();
    }

}