refactor ConfigHelper, split into multiple helper classes

14 files changed, 337 insertions, 260 deletions

diff --git a/app/src/main/java/se/leap/bitmaskclient/LeapSRPSession.java b/app/src/main/java/se/leap/bitmaskclient/LeapSRPSession.java
index 3a1fd6e0..d1f1ed21 100644
--- a/app/src/main/java/se/leap/bitmaskclient/LeapSRPSession.java
+++ b/app/src/main/java/se/leap/bitmaskclient/LeapSRPSession.java
@@ -17,12 +17,16 @@
 package se.leap.bitmaskclient;
 
 
-import org.jboss.security.srp.*;
+import org.jboss.security.srp.SRPParameters;
 
-import java.io.*;
-import java.math.*;
-import java.security.*;
-import java.util.*;
+import java.io.UnsupportedEncodingException;
+import java.math.BigInteger;
+import java.security.MessageDigest;
+import java.security.NoSuchAlgorithmException;
+import java.security.SecureRandom;
+import java.util.Arrays;
+
+import se.leap.bitmaskclient.utils.ConfigHelper;
 
 /**
  * Implements all SRP algorithm logic.
diff --git a/app/src/main/java/se/leap/bitmaskclient/MainActivity.java b/app/src/main/java/se/leap/bitmaskclient/MainActivity.java
index 4d57b6bc..8096607a 100644
--- a/app/src/main/java/se/leap/bitmaskclient/MainActivity.java
+++ b/app/src/main/java/se/leap/bitmaskclient/MainActivity.java
@@ -51,6 +51,7 @@ import se.leap.bitmaskclient.eip.EipCommand;
 import se.leap.bitmaskclient.eip.EipStatus;
 import se.leap.bitmaskclient.eip.VoidVpnService;
 import se.leap.bitmaskclient.fragments.LogFragment;
+import se.leap.bitmaskclient.utils.ConfigHelper;
 
 import static android.content.Intent.CATEGORY_DEFAULT;
 import static se.leap.bitmaskclient.Constants.BROADCAST_EIP_EVENT;
@@ -76,6 +77,8 @@ import static se.leap.bitmaskclient.ProviderAPI.INCORRECTLY_DOWNLOADED_VPN_CERTI
 import static se.leap.bitmaskclient.ProviderAPI.USER_MESSAGE;
 import static se.leap.bitmaskclient.R.string.downloading_vpn_certificate_failed;
 import static se.leap.bitmaskclient.R.string.vpn_certificate_user_message;
+import static se.leap.bitmaskclient.utils.PreferenceHelper.getSavedProviderFromSharedPreferences;
+import static se.leap.bitmaskclient.utils.PreferenceHelper.storeProviderInPreferences;
 
 
 public class MainActivity extends AppCompatActivity implements Observer {
@@ -123,7 +126,7 @@ public class MainActivity extends AppCompatActivity implements Observer {
                 getSupportFragmentManager().findFragmentById(R.id.navigation_drawer);
 
         preferences = getSharedPreferences(SHARED_PREFERENCES, MODE_PRIVATE);
-        provider = ConfigHelper.getSavedProviderFromSharedPreferences(preferences);
+        provider = getSavedProviderFromSharedPreferences(preferences);
 
         // Set up the drawer.
         navigationDrawerFragment.setUp(
@@ -194,7 +197,7 @@ public class MainActivity extends AppCompatActivity implements Observer {
                 return;
             }
 
-            ConfigHelper.storeProviderInPreferences(preferences, provider);
+            storeProviderInPreferences(preferences, provider);
             navigationDrawerFragment.refresh();
 
             switch (requestCode) {
@@ -321,7 +324,7 @@ public class MainActivity extends AppCompatActivity implements Observer {
 
             case CORRECTLY_DOWNLOADED_VPN_CERTIFICATE:
                 provider = resultData.getParcelable(PROVIDER_KEY);
-                ConfigHelper.storeProviderInPreferences(preferences, provider);
+                storeProviderInPreferences(preferences, provider);
                 EipCommand.startVPN(this, true);
                 break;
             case INCORRECTLY_DOWNLOADED_VPN_CERTIFICATE:
diff --git a/app/src/main/java/se/leap/bitmaskclient/Provider.java b/app/src/main/java/se/leap/bitmaskclient/Provider.java
index fd067bf9..5e5a3a62 100644
--- a/app/src/main/java/se/leap/bitmaskclient/Provider.java
+++ b/app/src/main/java/se/leap/bitmaskclient/Provider.java
@@ -140,7 +140,7 @@ public final class Provider implements Parcelable {
         return definition;
     }
 
-    String getDefinitionString() {
+    public String getDefinitionString() {
         return getDefinition().toString();
     }
 
@@ -148,7 +148,7 @@ public final class Provider implements Parcelable {
         return mainUrl.getDomain();
     }
 
-    String getMainUrlString() {
+    public String getMainUrlString() {
         return getMainUrl().toString();
     }
 
diff --git a/app/src/main/java/se/leap/bitmaskclient/ProviderApiManagerBase.java b/app/src/main/java/se/leap/bitmaskclient/ProviderApiManagerBase.java
index 2cde431e..25b5a56c 100644
--- a/app/src/main/java/se/leap/bitmaskclient/ProviderApiManagerBase.java
+++ b/app/src/main/java/se/leap/bitmaskclient/ProviderApiManagerBase.java
@@ -52,8 +52,9 @@ import javax.net.ssl.SSLHandshakeException;
 
 import okhttp3.OkHttpClient;
 import se.leap.bitmaskclient.Constants.CREDENTIAL_ERRORS;
+import se.leap.bitmaskclient.utils.ConfigHelper;
 
-import static se.leap.bitmaskclient.ConfigHelper.getFingerprintFromCertificate;
+import static se.leap.bitmaskclient.utils.ConfigHelper.getFingerprintFromCertificate;
 import static se.leap.bitmaskclient.Constants.BROADCAST_PROVIDER_API_EVENT;
 import static se.leap.bitmaskclient.Constants.BROADCAST_RESULT_CODE;
 import static se.leap.bitmaskclient.Constants.BROADCAST_RESULT_KEY;
@@ -103,6 +104,9 @@ import static se.leap.bitmaskclient.R.string.vpn_certificate_is_invalid;
 import static se.leap.bitmaskclient.R.string.warning_corrupted_provider_cert;
 import static se.leap.bitmaskclient.R.string.warning_corrupted_provider_details;
 import static se.leap.bitmaskclient.R.string.warning_expired_provider_cert;
+import static se.leap.bitmaskclient.utils.ConfigHelper.parseRsaKeyFromString;
+import static se.leap.bitmaskclient.utils.PreferenceHelper.deleteProviderDetailsFromPreferences;
+import static se.leap.bitmaskclient.utils.PreferenceHelper.getFromPersistedProvider;
 
 /**
  * Implements the logic of the http api calls. The methods of this class needs to be called from
@@ -218,7 +222,7 @@ public abstract class ProviderApiManagerBase {
 
     void resetProviderDetails(Provider provider) {
         provider.reset();
-        ConfigHelper.deleteProviderDetailsFromPreferences(preferences, provider.getDomain());
+        deleteProviderDetailsFromPreferences(preferences, provider.getDomain());
     }
 
     String formatErrorMessage(final int toastStringId) {
@@ -754,16 +758,16 @@ public abstract class ProviderApiManagerBase {
     }
 
     protected String getPersistedPrivateKey(String providerDomain) {
-        return ConfigHelper.getFromPersistedProvider(PROVIDER_PRIVATE_KEY, providerDomain, preferences);
+        return getFromPersistedProvider(PROVIDER_PRIVATE_KEY, providerDomain, preferences);
     }
 
     protected String getPersistedVPNCertificate(String providerDomain) {
-        return ConfigHelper.getFromPersistedProvider(PROVIDER_VPN_CERTIFICATE, providerDomain, preferences);
+        return getFromPersistedProvider(PROVIDER_VPN_CERTIFICATE, providerDomain, preferences);
     }
 
     protected JSONObject getPersistedProviderDefinition(String providerDomain) {
         try {
-            return new JSONObject(ConfigHelper.getFromPersistedProvider(Provider.KEY, providerDomain, preferences));
+            return new JSONObject(getFromPersistedProvider(Provider.KEY, providerDomain, preferences));
         } catch (JSONException e) {
             e.printStackTrace();
             return new JSONObject();
@@ -849,7 +853,7 @@ public abstract class ProviderApiManagerBase {
                 }
             }
 
-            RSAPrivateKey key = ConfigHelper.parseRsaKeyFromString(keyString);
+            RSAPrivateKey key = parseRsaKeyFromString(keyString);
             keyString = Base64.encodeToString(key.getEncoded(), Base64.DEFAULT);
             provider.setPrivateKey( "-----BEGIN RSA PRIVATE KEY-----\n" + keyString + "-----END RSA PRIVATE KEY-----");
 
diff --git a/app/src/main/java/se/leap/bitmaskclient/StartActivity.java b/app/src/main/java/se/leap/bitmaskclient/StartActivity.java
index 6bbdeb4f..33c13b90 100644
--- a/app/src/main/java/se/leap/bitmaskclient/StartActivity.java
+++ b/app/src/main/java/se/leap/bitmaskclient/StartActivity.java
@@ -15,6 +15,7 @@ import java.lang.annotation.RetentionPolicy;
 import de.blinkt.openvpn.core.VpnStatus;
 import se.leap.bitmaskclient.eip.EipCommand;
 import se.leap.bitmaskclient.userstatus.User;
+import se.leap.bitmaskclient.utils.ConfigHelper;
 
 import static se.leap.bitmaskclient.Constants.APP_ACTION_CONFIGURE_ALWAYS_ON_PROFILE;
 import static se.leap.bitmaskclient.Constants.EIP_RESTART_ON_BOOT;
@@ -24,6 +25,9 @@ import static se.leap.bitmaskclient.Constants.PROVIDER_KEY;
 import static se.leap.bitmaskclient.Constants.REQUEST_CODE_CONFIGURE_LEAP;
 import static se.leap.bitmaskclient.Constants.SHARED_PREFERENCES;
 import static se.leap.bitmaskclient.MainActivity.ACTION_SHOW_VPN_FRAGMENT;
+import static se.leap.bitmaskclient.utils.PreferenceHelper.getSavedProviderFromSharedPreferences;
+import static se.leap.bitmaskclient.utils.PreferenceHelper.providerInSharedPreferences;
+import static se.leap.bitmaskclient.utils.PreferenceHelper.storeProviderInPreferences;
 
 /**
  * Activity shown at startup. Evaluates if App is started for the first time or has been upgraded
@@ -154,9 +158,9 @@ public class StartActivity extends Activity{
     }
 
     private void prepareEIP() {
-        boolean provider_exists = ConfigHelper.providerInSharedPreferences(preferences);
+        boolean provider_exists = providerInSharedPreferences(preferences);
         if (provider_exists) {
-            Provider provider = ConfigHelper.getSavedProviderFromSharedPreferences(preferences);
+            Provider provider = getSavedProviderFromSharedPreferences(preferences);
             if(!provider.isConfigured()) {
                 configureLeapProvider();
             } else {
@@ -186,7 +190,7 @@ public class StartActivity extends Activity{
         if (requestCode == REQUEST_CODE_CONFIGURE_LEAP) {
             if (resultCode == RESULT_OK && data != null && data.hasExtra(Provider.KEY)) {
                 Provider provider = data.getParcelableExtra(Provider.KEY);
-                ConfigHelper.storeProviderInPreferences(preferences, provider);
+                storeProviderInPreferences(preferences, provider);
                 EipCommand.startVPN(this, false);
                 showMainActivity();
             } else if (resultCode == RESULT_CANCELED) {
diff --git a/app/src/main/java/se/leap/bitmaskclient/TLSCompatSocketFactory.java b/app/src/main/java/se/leap/bitmaskclient/TLSCompatSocketFactory.java
index 76d38447..cca75bdf 100644
--- a/app/src/main/java/se/leap/bitmaskclient/TLSCompatSocketFactory.java
+++ b/app/src/main/java/se/leap/bitmaskclient/TLSCompatSocketFactory.java
@@ -22,6 +22,7 @@ import javax.net.ssl.TrustManagerFactory;
 import javax.net.ssl.X509TrustManager;
 
 import okhttp3.OkHttpClient;
+import se.leap.bitmaskclient.utils.ConfigHelper;
 
 /**
  * Created by cyberta on 24.10.17.
diff --git a/app/src/main/java/se/leap/bitmaskclient/drawer/NavigationDrawerFragment.java b/app/src/main/java/se/leap/bitmaskclient/drawer/NavigationDrawerFragment.java
index 9256c136..badc85ea 100644
--- a/app/src/main/java/se/leap/bitmaskclient/drawer/NavigationDrawerFragment.java
+++ b/app/src/main/java/se/leap/bitmaskclient/drawer/NavigationDrawerFragment.java
@@ -46,9 +46,8 @@ import android.widget.AdapterView;
 import android.widget.ArrayAdapter;
 import android.widget.CompoundButton;
 import android.widget.ListView;
-import android.widget.Toast;
 
-import se.leap.bitmaskclient.ConfigHelper;
+import se.leap.bitmaskclient.utils.ConfigHelper;
 import se.leap.bitmaskclient.DrawerSettingsAdapter;
 import se.leap.bitmaskclient.DrawerSettingsAdapter.DrawerSettingsItem;
 import se.leap.bitmaskclient.FragmentManagerEnhanced;
@@ -62,8 +61,6 @@ import se.leap.bitmaskclient.fragments.LogFragment;
 
 import static android.content.Context.MODE_PRIVATE;
 import static se.leap.bitmaskclient.BitmaskApp.getRefWatcher;
-import static se.leap.bitmaskclient.ConfigHelper.getSaveBattery;
-import static se.leap.bitmaskclient.ConfigHelper.getShowAlwaysOnDialog;
 import static se.leap.bitmaskclient.Constants.PROVIDER_KEY;
 import static se.leap.bitmaskclient.Constants.REQUEST_CODE_SWITCH_PROVIDER;
 import static se.leap.bitmaskclient.Constants.SHARED_PREFERENCES;
@@ -77,6 +74,11 @@ import static se.leap.bitmaskclient.DrawerSettingsAdapter.SWITCH_PROVIDER;
 import static se.leap.bitmaskclient.R.string.about_fragment_title;
 import static se.leap.bitmaskclient.R.string.log_fragment_title;
 import static se.leap.bitmaskclient.R.string.switch_provider_menu_option;
+import static se.leap.bitmaskclient.utils.PreferenceHelper.getProviderName;
+import static se.leap.bitmaskclient.utils.PreferenceHelper.getSaveBattery;
+import static se.leap.bitmaskclient.utils.PreferenceHelper.getSavedProviderFromSharedPreferences;
+import static se.leap.bitmaskclient.utils.PreferenceHelper.getShowAlwaysOnDialog;
+import static se.leap.bitmaskclient.utils.PreferenceHelper.saveBattery;
 
 /**
  * Fragment used for managing interactions for and presentation of a navigation drawer.
@@ -307,7 +309,7 @@ public class NavigationDrawerFragment extends Fragment {
                             DrawerSettingsItem item = settingsListAdapter.getDrawerItem(BATTERY_SAVER);
                             item.setChecked(true);
                             settingsListAdapter.notifyDataSetChanged();
-                            ConfigHelper.saveBattery(getContext(), item.isChecked());
+                            saveBattery(getContext(), item.isChecked());
                         }
                     })
                     .setNegativeButton(activity.getString(android.R.string.no), new DialogInterface.OnClickListener() {
@@ -392,14 +394,14 @@ public class NavigationDrawerFragment extends Fragment {
     private void onSwitchItemSelected(int elementType, boolean newStateIsChecked) {
         switch (elementType) {
             case BATTERY_SAVER:
-                if (ConfigHelper.getSaveBattery(getContext()) == newStateIsChecked) {
+                if (getSaveBattery(getContext()) == newStateIsChecked) {
                     //initial ui setup, ignore
                     return;
                 }
                 if (newStateIsChecked) {
                     showExperimentalFeatureAlert();
                 } else {
-                    ConfigHelper.saveBattery(this.getContext(), false);
+                    saveBattery(this.getContext(), false);
                     disableSwitch(BATTERY_SAVER);
                 }
                 break;
@@ -423,7 +425,7 @@ public class NavigationDrawerFragment extends Fragment {
             mTitle = getString(R.string.vpn_fragment_title);
             fragment = new EipFragment();
             Bundle arguments = new Bundle();
-            Provider currentProvider = ConfigHelper.getSavedProviderFromSharedPreferences(preferences);
+            Provider currentProvider = getSavedProviderFromSharedPreferences(preferences);
             arguments.putParcelable(PROVIDER_KEY, currentProvider);
             fragment.setArguments(arguments);
         } else {
@@ -481,7 +483,7 @@ public class NavigationDrawerFragment extends Fragment {
 
     private void createListAdapterData() {
         accountListAdapter.clear();
-        String providerName = ConfigHelper.getProviderName(preferences);
+        String providerName = getProviderName(preferences);
         if (providerName == null) {
             //TODO: ADD A header to the ListView containing a useful message.
             //TODO 2: disable switchProvider
diff --git a/app/src/main/java/se/leap/bitmaskclient/eip/VpnCertificateValidator.java b/app/src/main/java/se/leap/bitmaskclient/eip/VpnCertificateValidator.java
index 03dd9d05..83904729 100644
--- a/app/src/main/java/se/leap/bitmaskclient/eip/VpnCertificateValidator.java
+++ b/app/src/main/java/se/leap/bitmaskclient/eip/VpnCertificateValidator.java
@@ -22,7 +22,7 @@ import java.security.cert.X509Certificate;
 import java.util.Calendar;
 import java.util.Date;
 
-import se.leap.bitmaskclient.ConfigHelper;
+import se.leap.bitmaskclient.utils.ConfigHelper;
 
 public class VpnCertificateValidator {
     public final static String TAG = VpnCertificateValidator.class.getSimpleName();
diff --git a/app/src/main/java/se/leap/bitmaskclient/fragments/AlwaysOnDialog.java b/app/src/main/java/se/leap/bitmaskclient/fragments/AlwaysOnDialog.java
index 3558f378..e3d004f5 100644
--- a/app/src/main/java/se/leap/bitmaskclient/fragments/AlwaysOnDialog.java
+++ b/app/src/main/java/se/leap/bitmaskclient/fragments/AlwaysOnDialog.java
@@ -17,7 +17,8 @@ import butterknife.InjectView;
 import se.leap.bitmaskclient.R;
 import se.leap.bitmaskclient.views.IconTextView;
 
-import static se.leap.bitmaskclient.ConfigHelper.saveShowAlwaysOnDialog;
+import static se.leap.bitmaskclient.utils.PreferenceHelper.saveShowAlwaysOnDialog;
+
 
 /**
  * Created by cyberta on 25.02.18.
diff --git a/app/src/main/java/se/leap/bitmaskclient/utils/ConfigHelper.java b/app/src/main/java/se/leap/bitmaskclient/utils/ConfigHelper.java
new file mode 100644
index 00000000..bb9fb2d4
--- /dev/null
+++ b/app/src/main/java/se/leap/bitmaskclient/utils/ConfigHelper.java
@@ -0,0 +1,161 @@
+/**
+ * Copyright (c) 2013 LEAP Encryption Access Project and contributers
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the 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
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ */
+package se.leap.bitmaskclient.utils;
+
+import android.support.annotation.NonNull;
+
+import org.json.JSONException;
+import org.json.JSONObject;
+import org.spongycastle.util.encoders.Base64;
+
+import java.io.ByteArrayInputStream;
+import java.io.IOException;
+import java.io.InputStream;
+import java.math.BigInteger;
+import java.security.KeyFactory;
+import java.security.MessageDigest;
+import java.security.NoSuchAlgorithmException;
+import java.security.NoSuchProviderException;
+import java.security.cert.CertificateEncodingException;
+import java.security.cert.CertificateException;
+import java.security.cert.CertificateFactory;
+import java.security.cert.X509Certificate;
+import java.security.interfaces.RSAPrivateKey;
+import java.security.spec.InvalidKeySpecException;
+import java.security.spec.PKCS8EncodedKeySpec;
+
+import se.leap.bitmaskclient.ProviderAPI;
+
+/**
+ * Stores constants, and implements auxiliary methods used across all Bitmask Android classes.
+ *
+ * @author parmegv
+ * @author MeanderingCode
+ */
+public class ConfigHelper {
+    final public static String NG_1024 =
+            "eeaf0ab9adb38dd69c33f80afa8fc5e86072618775ff3c0b9ea2314c9c256576d674df7496ea81d3383b4813d692c6e0e0d5d8e250b98be48e495c1d6089dad15dc7d7b46154d6b6ce8ef4ad69b15d4982559b297bcf1885c529f566660e57ec68edbc3c05726cc02fd4cbf4976eaa9afd5138fe8376435b9fc61d2fc0eb06e3";
+    final public static BigInteger G = new BigInteger("2");
+
+    public static boolean checkErroneousDownload(String downloadedString) {
+        try {
+            if (downloadedString == null || downloadedString.isEmpty() || new JSONObject(downloadedString).has(ProviderAPI.ERRORS) || new JSONObject(downloadedString).has(ProviderAPI.BACKEND_ERROR_KEY)) {
+                return true;
+            } else {
+                return false;
+            }
+        } catch (NullPointerException | JSONException e) {
+            return false;
+        }
+    }
+
+    /**
+     * Treat the input as the MSB representation of a number,
+     * and lop off leading zero elements.  For efficiency, the
+     * input is simply returned if no leading zeroes are found.
+     *
+     * @param in array to be trimmed
+     */
+    public static byte[] trim(byte[] in) {
+        if (in.length == 0 || in[0] != 0)
+            return in;
+
+        int len = in.length;
+        int i = 1;
+        while (in[i] == 0 && i < len)
+            ++i;
+        byte[] ret = new byte[len - i];
+        System.arraycopy(in, i, ret, 0, len - i);
+        return ret;
+    }
+
+    public static X509Certificate parseX509CertificateFromString(String certificateString) {
+        java.security.cert.Certificate certificate = null;
+        CertificateFactory cf;
+        try {
+            cf = CertificateFactory.getInstance("X.509");
+
+            certificateString = certificateString.replaceFirst("-----BEGIN CERTIFICATE-----", "").replaceFirst("-----END CERTIFICATE-----", "").trim();
+            byte[] cert_bytes = Base64.decode(certificateString);
+            InputStream caInput = new ByteArrayInputStream(cert_bytes);
+            try {
+                certificate = cf.generateCertificate(caInput);
+                System.out.println("ca=" + ((X509Certificate) certificate).getSubjectDN());
+            } finally {
+                caInput.close();
+            }
+        } catch (NullPointerException | CertificateException | IOException | IllegalArgumentException e) {
+            return null;
+        }
+        return (X509Certificate) certificate;
+    }
+
+    public static RSAPrivateKey parseRsaKeyFromString(String rsaKeyString) {
+        RSAPrivateKey key;
+        try {
+            KeyFactory kf = KeyFactory.getInstance("RSA", "BC");
+            rsaKeyString = rsaKeyString.replaceFirst("-----BEGIN RSA PRIVATE KEY-----", "").replaceFirst("-----END RSA PRIVATE KEY-----", "");
+            PKCS8EncodedKeySpec keySpec = new PKCS8EncodedKeySpec(Base64.decode(rsaKeyString));
+            key = (RSAPrivateKey) kf.generatePrivate(keySpec);
+        } catch (InvalidKeySpecException e) {
+            // TODO Auto-generated catch block
+            e.printStackTrace();
+            return null;
+        } catch (NoSuchAlgorithmException e) {
+            // TODO Auto-generated catch block
+            e.printStackTrace();
+            return null;
+        } catch (NoSuchProviderException e) {
+            // TODO Auto-generated catch block
+            e.printStackTrace();
+            return null;
+        } catch (NullPointerException e) {
+            e.printStackTrace();
+            return null;
+        }
+
+        return key;
+    }
+
+    private static String byteArrayToHex(byte[] input) {
+        int readBytes = input.length;
+        StringBuffer hexData = new StringBuffer();
+        int onebyte;
+        for (int i = 0; i < readBytes; i++) {
+            onebyte = ((0x000000ff & input[i]) | 0xffffff00);
+            hexData.append(Integer.toHexString(onebyte).substring(6));
+        }
+        return hexData.toString();
+    }
+
+    /**
+     * Calculates the hexadecimal representation of a sha256/sha1 fingerprint of a certificate
+     *
+     * @param certificate
+     * @param encoding
+     * @return
+     * @throws NoSuchAlgorithmException
+     * @throws CertificateEncodingException
+     */
+    @NonNull
+    public static String getFingerprintFromCertificate(X509Certificate certificate, String encoding) throws NoSuchAlgorithmException, CertificateEncodingException /*, UnsupportedEncodingException*/ {
+        byte[] byteArray = MessageDigest.getInstance(encoding).digest(certificate.getEncoded());
+        return byteArrayToHex(byteArray);
+    }
+
+
+}
diff --git a/app/src/main/java/se/leap/bitmaskclient/utils/FileHelper.java b/app/src/main/java/se/leap/bitmaskclient/utils/FileHelper.java
new file mode 100644
index 00000000..1c3e1ebb
--- /dev/null
+++ b/app/src/main/java/se/leap/bitmaskclient/utils/FileHelper.java
@@ -0,0 +1,22 @@
+package se.leap.bitmaskclient.utils;
+
+import java.io.File;
+import java.io.FileWriter;
+import java.io.IOException;
+
+/**
+ * Created by cyberta on 18.03.18.
+ */
+
+public class FileHelper {
+    public static File createFile(File dir, String fileName) {
+        return new File(dir, fileName);
+    }
+
+    public static void persistFile(File file, String content) throws IOException {
+        FileWriter writer = new FileWriter(file);
+        writer.write(content);
+        writer.close();
+    }
+
+}
diff --git a/app/src/main/java/se/leap/bitmaskclient/utils/InputStreamHelper.java b/app/src/main/java/se/leap/bitmaskclient/utils/InputStreamHelper.java
new file mode 100644
index 00000000..87996615
--- /dev/null
+++ b/app/src/main/java/se/leap/bitmaskclient/utils/InputStreamHelper.java
@@ -0,0 +1,21 @@
+package se.leap.bitmaskclient.utils;
+
+import java.io.FileInputStream;
+import java.io.FileNotFoundException;
+import java.io.InputStream;
+
+/**
+ * Created by cyberta on 18.03.18.
+ */
+
+public class InputStreamHelper {
+    //allows us to mock FileInputStream
+    public static InputStream getInputStreamFrom(String filePath) throws FileNotFoundException {
+        return new FileInputStream(filePath);
+    }
+
+    public static String loadInputStreamAsString(InputStream is) {
+        java.util.Scanner s = new java.util.Scanner(is).useDelimiter("\\A");
+        return s.hasNext() ? s.next() : "";
+    }
+}
diff --git a/app/src/main/java/se/leap/bitmaskclient/utils/KeyStoreHelper.java b/app/src/main/java/se/leap/bitmaskclient/utils/KeyStoreHelper.java
new file mode 100644
index 00000000..0cc9687b
--- /dev/null
+++ b/app/src/main/java/se/leap/bitmaskclient/utils/KeyStoreHelper.java
@@ -0,0 +1,79 @@
+package se.leap.bitmaskclient.utils;
+
+import java.io.IOException;
+import java.io.InputStream;
+import java.math.BigInteger;
+import java.security.KeyStore;
+import java.security.KeyStoreException;
+import java.security.NoSuchAlgorithmException;
+import java.security.cert.CertificateException;
+import java.security.cert.CertificateFactory;
+import java.security.cert.X509Certificate;
+
+/**
+ * Created by cyberta on 18.03.18.
+ */
+
+public class KeyStoreHelper {
+    private static KeyStore keystore_trusted;
+
+    /**
+     * Adds a new X509 certificate given its input stream and its provider name
+     *
+     * @param provider    used to store the certificate in the keystore
+     * @param inputStream from which X509 certificate must be generated.
+     */
+    public static void addTrustedCertificate(String provider, InputStream inputStream) {
+        CertificateFactory cf;
+        try {
+            cf = CertificateFactory.getInstance("X.509");
+            X509Certificate cert =
+                    (X509Certificate) cf.generateCertificate(inputStream);
+            keystore_trusted.setCertificateEntry(provider, cert);
+        } catch (CertificateException e) {
+            // TODO Auto-generated catch block
+            e.printStackTrace();
+        } catch (KeyStoreException e) {
+            // TODO Auto-generated catch block
+            e.printStackTrace();
+        }
+    }
+
+    /**
+     * Adds a new X509 certificate given in its string from and using its provider name
+     *
+     * @param provider    used to store the certificate in the keystore
+     * @param certificate
+     */
+    public static void addTrustedCertificate(String provider, String certificate) {
+
+        try {
+            X509Certificate cert = ConfigHelper.parseX509CertificateFromString(certificate);
+            if (keystore_trusted == null) {
+                keystore_trusted = KeyStore.getInstance("BKS");
+                keystore_trusted.load(null);
+            }
+            keystore_trusted.setCertificateEntry(provider, cert);
+        } catch (KeyStoreException e) {
+            // TODO Auto-generated catch block
+            e.printStackTrace();
+        } catch (NoSuchAlgorithmException e) {
+            // TODO Auto-generated catch block
+            e.printStackTrace();
+        } catch (CertificateException e) {
+            // TODO Auto-generated catch block
+            e.printStackTrace();
+        } catch (IOException e) {
+            // TODO Auto-generated catch block
+            e.printStackTrace();
+        }
+    }
+
+    /**
+     * @return class wide keystore
+     */
+    public static KeyStore getKeystore() {
+        return keystore_trusted;
+    }
+
+}
diff --git a/app/src/main/java/se/leap/bitmaskclient/ConfigHelper.java b/app/src/main/java/se/leap/bitmaskclient/utils/PreferenceHelper.java
index aaff9ebc..92f025b2 100644
--- a/app/src/main/java/se/leap/bitmaskclient/ConfigHelper.java
+++ b/app/src/main/java/se/leap/bitmaskclient/utils/PreferenceHelper.java
@@ -1,63 +1,23 @@
-/**
- * Copyright (c) 2013 LEAP Encryption Access Project and contributers
- *
- * This program is free software: you can redistribute it and/or modify
- * it under the terms of the 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
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program. If not, see <http://www.gnu.org/licenses/>.
- */
-package se.leap.bitmaskclient;
+package se.leap.bitmaskclient.utils;
 
 import android.content.Context;
 import android.content.SharedPreferences;
 import android.preference.PreferenceManager;
 import android.support.annotation.NonNull;
 import android.support.annotation.Nullable;
-import android.util.Log;
 
 import org.json.JSONException;
 import org.json.JSONObject;
-import org.spongycastle.util.encoders.Base64;
 
-import java.io.BufferedReader;
-import java.io.ByteArrayInputStream;
-import java.io.FileInputStream;
-import java.io.FileNotFoundException;
-import java.io.IOException;
-import java.io.InputStream;
-import java.io.InputStreamReader;
-import java.math.BigInteger;
 import java.net.MalformedURLException;
 import java.net.URL;
-import java.security.KeyFactory;
-import java.security.KeyStore;
-import java.security.KeyStoreException;
-import java.security.MessageDigest;
-import java.security.NoSuchAlgorithmException;
-import java.security.NoSuchProviderException;
-import java.security.cert.CertificateEncodingException;
-import java.security.cert.CertificateException;
-import java.security.cert.CertificateFactory;
-import java.security.cert.X509Certificate;
-import java.security.interfaces.RSAPrivateKey;
-import java.security.spec.InvalidKeySpecException;
-import java.security.spec.PKCS8EncodedKeySpec;
 import java.util.ArrayList;
-import java.util.HashSet;
 import java.util.List;
 import java.util.Locale;
 import java.util.Map;
-import java.util.Set;
 
-import static android.R.attr.name;
+import se.leap.bitmaskclient.Provider;
+
 import static se.leap.bitmaskclient.Constants.ALWAYS_ON_SHOW_DIALOG;
 import static se.leap.bitmaskclient.Constants.DEFAULT_SHARED_PREFS_BATTERY_SAVER;
 import static se.leap.bitmaskclient.Constants.PREFERENCES_APP_VERSION;
@@ -68,195 +28,10 @@ import static se.leap.bitmaskclient.Constants.PROVIDER_VPN_CERTIFICATE;
 import static se.leap.bitmaskclient.Constants.SHARED_PREFERENCES;
 
 /**
- * Stores constants, and implements auxiliary methods used across all Bitmask Android classes.
- *
- * @author parmegv
- * @author MeanderingCode
+ * Created by cyberta on 18.03.18.
  */
-public class ConfigHelper {
-    private static final String TAG = ConfigHelper.class.getName();
-    private static KeyStore keystore_trusted;
-
-    final public static String NG_1024 =
-            "eeaf0ab9adb38dd69c33f80afa8fc5e86072618775ff3c0b9ea2314c9c256576d674df7496ea81d3383b4813d692c6e0e0d5d8e250b98be48e495c1d6089dad15dc7d7b46154d6b6ce8ef4ad69b15d4982559b297bcf1885c529f566660e57ec68edbc3c05726cc02fd4cbf4976eaa9afd5138fe8376435b9fc61d2fc0eb06e3";
-    final public static BigInteger G = new BigInteger("2");
-
-    public static boolean checkErroneousDownload(String downloadedString) {
-        try {
-            if (downloadedString == null || downloadedString.isEmpty() || new JSONObject(downloadedString).has(ProviderAPI.ERRORS) || new JSONObject(downloadedString).has(ProviderAPI.BACKEND_ERROR_KEY)) {
-                return true;
-            } else {
-                return false;
-            }
-        } catch (NullPointerException | JSONException e) {
-            return false;
-        }
-    }
-
-    /**
-     * Treat the input as the MSB representation of a number,
-     * and lop off leading zero elements.  For efficiency, the
-     * input is simply returned if no leading zeroes are found.
-     *
-     * @param in array to be trimmed
-     */
-    public static byte[] trim(byte[] in) {
-        if (in.length == 0 || in[0] != 0)
-            return in;
-
-        int len = in.length;
-        int i = 1;
-        while (in[i] == 0 && i < len)
-            ++i;
-        byte[] ret = new byte[len - i];
-        System.arraycopy(in, i, ret, 0, len - i);
-        return ret;
-    }
-
-    public static X509Certificate parseX509CertificateFromString(String certificateString) {
-        java.security.cert.Certificate certificate = null;
-        CertificateFactory cf;
-        try {
-            cf = CertificateFactory.getInstance("X.509");
-
-            certificateString = certificateString.replaceFirst("-----BEGIN CERTIFICATE-----", "").replaceFirst("-----END CERTIFICATE-----", "").trim();
-            byte[] cert_bytes = Base64.decode(certificateString);
-            InputStream caInput = new ByteArrayInputStream(cert_bytes);
-            try {
-                certificate = cf.generateCertificate(caInput);
-                System.out.println("ca=" + ((X509Certificate) certificate).getSubjectDN());
-            } finally {
-                caInput.close();
-            }
-        } catch (NullPointerException | CertificateException | IOException | IllegalArgumentException e) {
-            return null;
-        }
-        return (X509Certificate) certificate;
-    }
-
-    public static String loadInputStreamAsString(java.io.InputStream is) {
-        java.util.Scanner s = new java.util.Scanner(is).useDelimiter("\\A");
-        return s.hasNext() ? s.next() : "";
-    }
-
-    //allows us to mock FileInputStream
-    public static InputStream getInputStreamFrom(String filePath) throws FileNotFoundException {
-        return new FileInputStream(filePath);
-    }
-
-    protected static RSAPrivateKey parseRsaKeyFromString(String rsaKeyString) {
-        RSAPrivateKey key;
-        try {
-            KeyFactory kf = KeyFactory.getInstance("RSA", "BC");
-            rsaKeyString = rsaKeyString.replaceFirst("-----BEGIN RSA PRIVATE KEY-----", "").replaceFirst("-----END RSA PRIVATE KEY-----", "");
-            PKCS8EncodedKeySpec keySpec = new PKCS8EncodedKeySpec(Base64.decode(rsaKeyString));
-            key = (RSAPrivateKey) kf.generatePrivate(keySpec);
-        } catch (InvalidKeySpecException e) {
-            // TODO Auto-generated catch block
-            e.printStackTrace();
-            return null;
-        } catch (NoSuchAlgorithmException e) {
-            // TODO Auto-generated catch block
-            e.printStackTrace();
-            return null;
-        } catch (NoSuchProviderException e) {
-            // TODO Auto-generated catch block
-            e.printStackTrace();
-            return null;
-        } catch (NullPointerException e) {
-            e.printStackTrace();
-            return null;
-        }
-
-        return key;
-    }
-
-    private static String byteArrayToHex(byte[] input) {
-        int readBytes = input.length;
-        StringBuffer hexData = new StringBuffer();
-        int onebyte;
-        for (int i = 0; i < readBytes; i++) {
-            onebyte = ((0x000000ff & input[i]) | 0xffffff00);
-            hexData.append(Integer.toHexString(onebyte).substring(6));
-        }
-        return hexData.toString();
-    }
-
-    /**
-     * Calculates the hexadecimal representation of a sha256/sha1 fingerprint of a certificate
-     *
-     * @param certificate
-     * @param encoding
-     * @return
-     * @throws NoSuchAlgorithmException
-     * @throws CertificateEncodingException
-     */
-    @NonNull
-    public static String getFingerprintFromCertificate(X509Certificate certificate, String encoding) throws NoSuchAlgorithmException, CertificateEncodingException /*, UnsupportedEncodingException*/ {
-        byte[] byteArray = MessageDigest.getInstance(encoding).digest(certificate.getEncoded());
-        return byteArrayToHex(byteArray);
-    }
-    
-    /**
-     * Adds a new X509 certificate given its input stream and its provider name
-     *
-     * @param provider    used to store the certificate in the keystore
-     * @param inputStream from which X509 certificate must be generated.
-     */
-    public static void addTrustedCertificate(String provider, InputStream inputStream) {
-        CertificateFactory cf;
-        try {
-            cf = CertificateFactory.getInstance("X.509");
-            X509Certificate cert =
-                    (X509Certificate) cf.generateCertificate(inputStream);
-            keystore_trusted.setCertificateEntry(provider, cert);
-        } catch (CertificateException e) {
-            // TODO Auto-generated catch block
-            e.printStackTrace();
-        } catch (KeyStoreException e) {
-            // TODO Auto-generated catch block
-            e.printStackTrace();
-        }
-    }
-
-    /**
-     * Adds a new X509 certificate given in its string from and using its provider name
-     *
-     * @param provider    used to store the certificate in the keystore
-     * @param certificate
-     */
-    public static void addTrustedCertificate(String provider, String certificate) {
-
-        try {
-            X509Certificate cert = ConfigHelper.parseX509CertificateFromString(certificate);
-            if (keystore_trusted == null) {
-                keystore_trusted = KeyStore.getInstance("BKS");
-                keystore_trusted.load(null);
-            }
-            keystore_trusted.setCertificateEntry(provider, cert);
-        } catch (KeyStoreException e) {
-            // TODO Auto-generated catch block
-            e.printStackTrace();
-        } catch (NoSuchAlgorithmException e) {
-            // TODO Auto-generated catch block
-            e.printStackTrace();
-        } catch (CertificateException e) {
-            // TODO Auto-generated catch block
-            e.printStackTrace();
-        } catch (IOException e) {
-            // TODO Auto-generated catch block
-            e.printStackTrace();
-        }
-    }
-
-    /**
-     * @return class wide keystore
-     */
-    public static KeyStore getKeystore() {
-        return keystore_trusted;
-    }
-
 
+public class PreferenceHelper {
     public static boolean providerInSharedPreferences(@NonNull SharedPreferences preferences) {
         return preferences.getBoolean(PROVIDER_CONFIGURED, false);
     }