com.gmu.uav.RadioSecurity.java Source code

Introduction

Here is the source code for com.gmu.uav.RadioSecurity.java

Source

package com.gmu.uav;

import java.math.BigInteger;
import java.security.MessageDigest;
import java.security.NoSuchAlgorithmException;
import java.security.SecureRandom;

import javax.crypto.Mac;
import javax.crypto.spec.SecretKeySpec;

import org.apache.commons.codec.binary.Hex;

/*
 * ECE798 - UAV RESEARCH PROJECT
 * GEORGE MASON UNIVERSITY
 * ANDREW KEENE
 * SUMMER/FALL 2012
 * 
 * Code Source Repository: http://code.google.com/p/gmu-ece798-research-project-uav/
 * Code License: GNU GPL V3
 * 
 * RadioSecurity.class : This class consists of the functions required to authenticate with the ground system.
 * Functions for computing the SHA256 and HMAC-SHA1 of a given ASCII String are found here.
 * 
 */

public class RadioSecurity {

    public static final int SALT_BYTES = 24;
    public static final int HASH_ITERATIONS = 1;

    public static String computeSHA256(String password) {
        MessageDigest messagDigest = null;
        String saltedPassword = null;

        SecureRandom random = new SecureRandom();
        byte[] salt = new byte[SALT_BYTES];
        random.nextBytes(salt);

        saltedPassword = salt + password;

        try {

            messagDigest = MessageDigest.getInstance("SHA-256");

        } catch (NoSuchAlgorithmException e) {

            e.printStackTrace();
        }

        messagDigest.update(saltedPassword.getBytes());

        byte finalHash[] = messagDigest.digest();

        return HASH_ITERATIONS + ":" + toHex(salt) + ":" + toHex(finalHash);
    }

    public static String hmacSha1(String value, byte[] key) {
        try {
            // Get an hmac_sha1 key from the raw key bytes    
            SecretKeySpec signingKey = new SecretKeySpec(key, "HmacSHA1");

            // Get an hmac_sha1 Mac instance and initialize with the signing key
            Mac mac = Mac.getInstance("HmacSHA1");
            mac.init(signingKey);

            // Compute the hmac on input data bytes
            byte[] rawHmac = mac.doFinal(value.getBytes());

            // Convert raw bytes to Hex
            byte[] hexBytes = new Hex().encode(rawHmac);

            //  Covert array of Hex bytes to a String
            return new String(hexBytes, "UTF-8");
        } catch (Exception e) {
            throw new RuntimeException(e);
        }
    }

    public static String toHex(byte[] array) {
        BigInteger bi = new BigInteger(1, array);
        String hex = bi.toString(16);
        int paddingLength = (array.length * 2) - hex.length();
        if (paddingLength > 0)
            return String.format("%0" + paddingLength + "d", 0) + hex;
        else
            return hex;
    }

    public static byte[] fromHex(String hex) {
        byte[] binary = new byte[hex.length() / 2];
        for (int i = 0; i < binary.length; i++) {
            binary[i] = (byte) Integer.parseInt(hex.substring(2 * i, 2 * i + 2), 16);
        }
        return binary;
    }
}