SecurityUtils.java

package com.themagpi.api;

import java.security.GeneralSecurityException;
import java.security.MessageDigest;
import java.security.NoSuchAlgorithmException;

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

import android.util.Base64;

public class SecurityUtils {

	private final static String HMAC_SHA1_ALGORITHM = "HmacSHA1";

	public static final String md5(final String s) {
		try {
			MessageDigest digest = java.security.MessageDigest
					.getInstance("MD5");
			digest.update(s.getBytes());
			byte messageDigest[] = digest.digest();

			StringBuffer hexString = new StringBuffer();
			for (int i = 0; i < messageDigest.length; i++) {
				String h = Integer.toHexString(0xFF & messageDigest[i]);
				while (h.length() < 2)
					h = "0" + h;
				hexString.append(h);
			}
			return hexString.toString();

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

	public static String Hmac(String secret, String data) {
		try {
			SecretKeySpec signingKey = new SecretKeySpec(secret.getBytes(), HMAC_SHA1_ALGORITHM);
			Mac mac = Mac.getInstance(HMAC_SHA1_ALGORITHM);
			mac.init(signingKey);
			byte[] rawHmac = mac.doFinal(data.getBytes());
			String result = Base64.encodeToString(rawHmac, Base64.NO_WRAP);
			return result;
		} catch (GeneralSecurityException e) {
			throw new IllegalArgumentException();
		}
	}
}