InstagramUtil.java

package com.insta4j.instagram.util;


import com.insta4j.instagram.exception.InstagramException;
import org.apache.commons.codec.binary.Hex;

import javax.crypto.Mac;
import javax.crypto.spec.SecretKeySpec;
import java.io.InputStream;
import java.security.InvalidKeyException;
import java.security.NoSuchAlgorithmException;
import java.util.Properties;

public class InstagramUtil {


	public static String createSHAKey(String ipAddress, String clientSecret) throws InstagramException {


		String digest = null;
		String clientSecretForSHA = getClientSecret();
		if (clientSecretForSHA == null || clientSecretForSHA.equals("")){
			clientSecretForSHA = clientSecret;
		}
		SecretKeySpec signingKey = new SecretKeySpec(clientSecretForSHA.getBytes(), Constants.HMAC_SHA256_ALGO);

		Mac mac = null;
		try {
			mac = Mac.getInstance(Constants.HMAC_SHA256_ALGO);
			mac.init(signingKey);
			byte[] rawHmac = mac.doFinal(ipAddress.getBytes());
			digest = Hex.encodeHexString(rawHmac);

		} catch (NoSuchAlgorithmException e) {
			throw new InstagramException(-1, e.getMessage(), "Undefined", e);
		}
		  catch (InvalidKeyException e) {
 		  throw new InstagramException(-1, e.getMessage(), "Undefined", e);
		}

		return digest;
	}

	public static String getClientSecret(){

		try {
			InputStream input = InstagramUtil.class.getClassLoader().getResourceAsStream("insta4jprop.properties");
			Properties prop = new Properties();
			prop.load(input);
			return prop.getProperty(Constants.PARAM_CLIENT_SECRET);
		}
		catch (Exception e) {

		}
		return null;
	}
}