edu.cwru.apo.Auth.java Source code

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Here is the source code for edu.cwru.apo.Auth.java

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/*
 * Copyright 2011 Devin Schwab, Umang Banugaria
 *
 * This file is part of the APO Theta Upsilon App for Case Western Reserve University's Alpha Phi Omega Theta Upsilon Chapter.
 *
 * The APO Theta Upsilon program is free software: you can redistribute it and/or modify
 * it under the terms of the Lesser GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * This program 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
 * Lesser GNU General Public License for more details.
 *
 * You should have received a copy of the Lesser GNU General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */

package edu.cwru.apo;

import java.io.IOException;
import java.io.InputStream;
import java.io.UnsupportedEncodingException;
import java.net.URLDecoder;
import java.net.URLEncoder;
import java.security.InvalidAlgorithmParameterException;
import java.security.InvalidKeyException;
import java.security.KeyFactory;
import java.security.MessageDigest;
import java.security.NoSuchAlgorithmException;
import java.security.NoSuchProviderException;
import java.security.PublicKey;
import java.security.SecureRandom;
import java.security.interfaces.RSAKey;
import java.security.spec.InvalidKeySpecException;
import java.security.spec.X509EncodedKeySpec;
import java.util.Calendar;
import java.util.Iterator;
import java.util.List;

import javax.crypto.BadPaddingException;
import javax.crypto.Cipher;
import javax.crypto.IllegalBlockSizeException;
import javax.crypto.KeyGenerator;
import javax.crypto.Mac;
import javax.crypto.NoSuchPaddingException;
import javax.crypto.SecretKey;
import javax.crypto.spec.IvParameterSpec;
import javax.crypto.spec.SecretKeySpec;

import org.apache.http.NameValuePair;

import android.content.Context;
import android.content.SharedPreferences;
import android.content.SharedPreferences.Editor;
import android.util.Base64;

public class Auth {

    private static int counter = 0;
    private static byte[] sharedSecret = null;
    public static boolean loggedIn;
    public static DynamicHmac Hmac = new DynamicHmac();

    // returns the number of milliseconds since 1970
    public static long getTimestamp() {
        Calendar cal = Calendar.getInstance();
        return cal.getTimeInMillis();
    }

    public static Hex md5(String in) {
        MessageDigest digest;
        try {
            digest = MessageDigest.getInstance("MD5");
            digest.reset();
            digest.update(in.getBytes());

            byte messageDigest[] = digest.digest();
            return new Hex(messageDigest);

        } catch (NoSuchAlgorithmException e) {
            e.printStackTrace();
        }
        return null;
    }

    public static void saveKeys(SharedPreferences prefs) {
        Editor edit = prefs.edit();
        edit.putString("secretKey", Auth.Hmac.getSecretKey().toString());
        edit.putInt("counter", Auth.Hmac.getCounter());
        edit.putInt("increment", Auth.Hmac.getIncrement());
        edit.commit();
    }

    public static void loadKeys(SharedPreferences prefs) {
        Hex secretKey = new Hex(prefs.getString("secretKey", "0"));
        int counter = prefs.getInt("counter", -1);
        int increment = prefs.getInt("increment", 0);
        if (secretKey.toString().compareTo("0") == 0)
            return;
        if (counter == -1)
            return;
        if (increment == 0)
            return;
        Auth.Hmac = new DynamicHmac(secretKey, counter, increment);
    }
}