oscarito9410

public static byte[] hexStringToByteArray(String s) {
    int len = s.length();
    byte[] data = new byte[len / 2];
    for (int i = 0; i < len; i += 2) {
        data[i / 2] = (byte) ((Character.digit(s.charAt(i), 16) << 4)
                + Character.digit(s.charAt(i + 1), 16));
    }
    return data;
}
// Ref: https://stackoverflow.com/questions/140131/convert-a-string-representation-of-a-hex-dump-to-a-byte-array-using-java/140861#140861

oscarito9410

import java.io.IOException;
import okhttp3.HttpUrl;
import okhttp3.Interceptor;
import okhttp3.OkHttpClient;
import okhttp3.Request;

/** An interceptor that allows runtime changes to the URL hostname. */
public final class HostSelectionInterceptor implements Interceptor {
  private volatile String host;

oscarito9410

package com.example.yourapp;

import java.io.IOException;
import java.util.ArrayList;
import java.util.Iterator;
import java.util.List;

import com.example.yourapp.AuthenticationModel;
import retrofit.client.Header;
import retrofit.client.OkClient;

oscarito9410

import android.content.Context;
import android.content.SharedPreferences;
import android.preference.PreferenceManager;
import android.security.KeyPairGeneratorSpec;
import android.text.TextUtils;
import android.util.Base64;
import android.util.Log;

import java.io.ByteArrayInputStream;