#8757 new ProviderApiBase includes commonly used code between different implementations of ProviderAPI

2 files changed, 63 insertions, 801 deletions

diff --git a/app/src/production/java/se/leap/bitmaskclient/ConfigurationWizard.java b/app/src/production/java/se/leap/bitmaskclient/ConfigurationWizard.java
index 61c6b7cf..2e5521b1 100644
--- a/app/src/production/java/se/leap/bitmaskclient/ConfigurationWizard.java
+++ b/app/src/production/java/se/leap/bitmaskclient/ConfigurationWizard.java
@@ -348,7 +348,7 @@ public class ConfigurationWizard extends Activity
      * use it anonymously (if possible)
      * or cancel his/her election pressing the back button.
      *
-     * @param view
+     *
      */
     private void showProviderDetails() {
         if (setting_up_provider) {
@@ -380,8 +380,6 @@ public class ConfigurationWizard extends Activity
     /**
      * Asks ProviderAPI to download a new provider.json file
      *
-     * @param provider_name
-     * @param provider_main_url
      */
     public void setUpProvider() {
         Intent provider_API_command = new Intent(this, ProviderAPI.class);
diff --git a/app/src/production/java/se/leap/bitmaskclient/ProviderAPI.java b/app/src/production/java/se/leap/bitmaskclient/ProviderAPI.java
index 08748f97..982080de 100644
--- a/app/src/production/java/se/leap/bitmaskclient/ProviderAPI.java
+++ b/app/src/production/java/se/leap/bitmaskclient/ProviderAPI.java
@@ -1,3 +1,4 @@
+
 /**
  * Copyright (c) 2013 LEAP Encryption Access Project and contributers
  *
@@ -16,15 +17,7 @@
  */
 package se.leap.bitmaskclient;
 
-import android.app.IntentService;
-import android.content.Intent;
-import android.content.SharedPreferences;
-import android.content.res.Resources;
-import android.os.Build;
 import android.os.Bundle;
-import android.os.ResultReceiver;
-import android.support.annotation.NonNull;
-import android.util.Base64;
 import android.util.Pair;
 
 import org.json.JSONException;
@@ -32,634 +25,32 @@ import org.json.JSONObject;
 import org.thoughtcrime.ssl.pinning.util.PinningHelper;
 
 import java.io.IOException;
-import java.io.InputStream;
-import java.math.BigInteger;
-import java.net.ConnectException;
-import java.net.MalformedURLException;
-import java.net.SocketTimeoutException;
 import java.net.URL;
-import java.net.UnknownHostException;
-import java.net.UnknownServiceException;
-import java.security.KeyManagementException;
-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.X509Certificate;
-import java.security.interfaces.RSAPrivateKey;
-import java.util.ArrayList;
-import java.util.Collections;
-import java.util.HashMap;
 import java.util.List;
-import java.util.Locale;
 import java.util.Scanner;
 
 import javax.net.ssl.HttpsURLConnection;
 import javax.net.ssl.SSLHandshakeException;
 
-import okhttp3.CipherSuite;
-import okhttp3.ConnectionSpec;
-import okhttp3.Cookie;
-import okhttp3.CookieJar;
-import okhttp3.HttpUrl;
-import okhttp3.MediaType;
 import okhttp3.OkHttpClient;
-import okhttp3.Request;
-import okhttp3.RequestBody;
-import okhttp3.Response;
-import okhttp3.TlsVersion;
 import se.leap.bitmaskclient.eip.Constants;
 import se.leap.bitmaskclient.eip.EIP;
-import se.leap.bitmaskclient.userstatus.SessionDialog;
-import se.leap.bitmaskclient.userstatus.User;
-import se.leap.bitmaskclient.userstatus.UserStatus;
 
-import static se.leap.bitmaskclient.R.string.certificate_error;
 import static se.leap.bitmaskclient.R.string.error_io_exception_user_message;
-import static se.leap.bitmaskclient.R.string.error_json_exception_user_message;
-import static se.leap.bitmaskclient.R.string.error_no_such_algorithm_exception_user_message;
-import static se.leap.bitmaskclient.R.string.keyChainAccessError;
 import static se.leap.bitmaskclient.R.string.malformed_url;
-import static se.leap.bitmaskclient.R.string.server_unreachable_message;
-import static se.leap.bitmaskclient.R.string.service_is_down_error;
 
 /**
  * Implements HTTP api methods used to manage communications with the provider server.
+ * It extends the abstract ProviderApiBase and implements the diverging method calls between the different flavors
+ * of ProviderAPI.
  * <p/>
- * It's an IntentService because it downloads data from the Internet, so it operates in the background.
+ * It extends an  IntentService because it downloads data from the Internet, so it operates in the background.
  *
  * @author parmegv
  * @author MeanderingCode
+ * @author cyberta
  */
-public class ProviderAPI extends IntentService {
-
-    final public static String
-            TAG = ProviderAPI.class.getSimpleName(),
-            SET_UP_PROVIDER = "setUpProvider",
-            DOWNLOAD_NEW_PROVIDER_DOTJSON = "downloadNewProviderDotJSON",
-            SIGN_UP = "srpRegister",
-            LOG_IN = "srpAuth",
-            LOG_OUT = "logOut",
-            DOWNLOAD_CERTIFICATE = "downloadUserAuthedCertificate",
-            PARAMETERS = "parameters",
-            RESULT_KEY = "result",
-            RECEIVER_KEY = "receiver",
-            ERRORS = "errors",
-            UPDATE_PROGRESSBAR = "update_progressbar",
-            CURRENT_PROGRESS = "current_progress",
-            DOWNLOAD_EIP_SERVICE = TAG + ".DOWNLOAD_EIP_SERVICE";
-
-    final public static int
-            SUCCESSFUL_LOGIN = 3,
-            FAILED_LOGIN = 4,
-            SUCCESSFUL_SIGNUP = 5,
-            FAILED_SIGNUP = 6,
-            SUCCESSFUL_LOGOUT = 7,
-            LOGOUT_FAILED = 8,
-            CORRECTLY_DOWNLOADED_CERTIFICATE = 9,
-            INCORRECTLY_DOWNLOADED_CERTIFICATE = 10,
-            PROVIDER_OK = 11,
-            PROVIDER_NOK = 12,
-            CORRECTLY_DOWNLOADED_EIP_SERVICE = 13,
-            INCORRECTLY_DOWNLOADED_EIP_SERVICE = 14;
-
-    private static boolean
-            CA_CERT_DOWNLOADED = false,
-            PROVIDER_JSON_DOWNLOADED = false,
-            EIP_SERVICE_JSON_DOWNLOADED = false;
-
-    private static String last_provider_main_url;
-    private static boolean go_ahead = true;
-    private static SharedPreferences preferences;
-    private static String provider_api_url;
-    private static String provider_ca_cert_fingerprint;
-    private Resources resources;
-
-    public static void stop() {
-        go_ahead = false;
-    }
-
-    private final MediaType JSON
-            = MediaType.parse("application/json; charset=utf-8");
-
-    public ProviderAPI() {
-        super(TAG);
-    }
-
-    @Override
-    public void onCreate() {
-        super.onCreate();
-
-        preferences = getSharedPreferences(Dashboard.SHARED_PREFERENCES, MODE_PRIVATE);
-        resources = getResources();
-    }
-
-    public static String lastProviderMainUrl() {
-        return last_provider_main_url;
-    }
-
-    @Override
-    protected void onHandleIntent(Intent command) {
-        final ResultReceiver receiver = command.getParcelableExtra(RECEIVER_KEY);
-        String action = command.getAction();
-        Bundle parameters = command.getBundleExtra(PARAMETERS);
-
-        if (provider_api_url == null && preferences.contains(Provider.KEY)) {
-            try {
-                JSONObject provider_json = new JSONObject(preferences.getString(Provider.KEY, ""));
-                provider_api_url = provider_json.getString(Provider.API_URL) + "/" + provider_json.getString(Provider.API_VERSION);
-                go_ahead = true;
-            } catch (JSONException e) {
-                go_ahead = false;
-            }
-        }
-
-        if (action.equalsIgnoreCase(SET_UP_PROVIDER)) {
-            Bundle result = setUpProvider(parameters);
-            if (go_ahead) {
-                if (result.getBoolean(RESULT_KEY)) {
-                    receiver.send(PROVIDER_OK, result);
-                } else {
-                    receiver.send(PROVIDER_NOK, result);
-                }
-            }
-        } else if (action.equalsIgnoreCase(SIGN_UP)) {
-            UserStatus.updateStatus(UserStatus.SessionStatus.SIGNING_UP, resources);
-            Bundle result = tryToRegister(parameters);
-            if (result.getBoolean(RESULT_KEY)) {
-                receiver.send(SUCCESSFUL_SIGNUP, result);
-            } else {
-                receiver.send(FAILED_SIGNUP, result);
-            }
-        } else if (action.equalsIgnoreCase(LOG_IN)) {
-            UserStatus.updateStatus(UserStatus.SessionStatus.LOGGING_IN, resources);
-            Bundle result = tryToAuthenticate(parameters);
-            if (result.getBoolean(RESULT_KEY)) {
-                receiver.send(SUCCESSFUL_LOGIN, result);
-                UserStatus.updateStatus(UserStatus.SessionStatus.LOGGED_IN, resources);
-            } else {
-                receiver.send(FAILED_LOGIN, result);
-                UserStatus.updateStatus(UserStatus.SessionStatus.NOT_LOGGED_IN, resources);
-            }
-        } else if (action.equalsIgnoreCase(LOG_OUT)) {
-            UserStatus.updateStatus(UserStatus.SessionStatus.LOGGING_OUT, resources);
-            if (logOut()) {
-                receiver.send(SUCCESSFUL_LOGOUT, Bundle.EMPTY);
-                UserStatus.updateStatus(UserStatus.SessionStatus.LOGGED_OUT, resources);
-            } else {
-                receiver.send(LOGOUT_FAILED, Bundle.EMPTY);
-                UserStatus.updateStatus(UserStatus.SessionStatus.DIDNT_LOG_OUT, resources);
-            }
-        } else if (action.equalsIgnoreCase(DOWNLOAD_CERTIFICATE)) {
-            if (updateVpnCertificate()) {
-                receiver.send(CORRECTLY_DOWNLOADED_CERTIFICATE, Bundle.EMPTY);
-            } else {
-                receiver.send(INCORRECTLY_DOWNLOADED_CERTIFICATE, Bundle.EMPTY);
-            }
-        } else if (action.equalsIgnoreCase(DOWNLOAD_EIP_SERVICE)) {
-            Bundle result = getAndSetEipServiceJson();
-            if (result.getBoolean(RESULT_KEY)) {
-                receiver.send(CORRECTLY_DOWNLOADED_EIP_SERVICE, result);
-            } else {
-                receiver.send(INCORRECTLY_DOWNLOADED_EIP_SERVICE, result);
-            }
-        }
-    }
-
-    private String formatErrorMessage(final int toastStringId) {
-        return formatErrorMessage(getResources().getString(toastStringId));
-    }
-
-    private String formatErrorMessage(String errorMessage) {
-        return "{ \"" + ERRORS + "\" : \"" + errorMessage + "\" }";
-    }
-
-    private JSONObject getErrorMessageAsJson(final int toastStringId) {
-        try {
-            return new JSONObject(formatErrorMessage(toastStringId));
-        } catch (JSONException e) {
-            e.printStackTrace();
-            return new JSONObject();
-        }
-    }
-
-    private JSONObject getErrorMessageAsJson(String message) {
-        try {
-            return new JSONObject(formatErrorMessage(message));
-        } catch (JSONException e) {
-            e.printStackTrace();
-            return new JSONObject();
-        }
-    }
-    private OkHttpClient initHttpClient(JSONObject initError, boolean isSelfSigned) {
-        try {
-            TLSCompatSocketFactory sslCompatFactory;
-            ConnectionSpec spec = getConnectionSpec();
-            OkHttpClient.Builder clientBuilder = new OkHttpClient.Builder();
-            if (isSelfSigned) {
-                sslCompatFactory = new TLSCompatSocketFactory(preferences.getString(Provider.CA_CERT, ""));
-
-            } else {
-                sslCompatFactory = new TLSCompatSocketFactory();
-            }
-            sslCompatFactory.initSSLSocketFactory(clientBuilder);
-            clientBuilder.cookieJar(getCookieJar())
-                    .connectionSpecs(Collections.singletonList(spec));
-            return clientBuilder.build();
-        } catch (IllegalStateException e) {
-            e.printStackTrace();
-            initError = getErrorMessageAsJson(String.format(resources.getString(keyChainAccessError), e.getLocalizedMessage()));
-        } catch (KeyStoreException e) {
-            e.printStackTrace();
-            initError = getErrorMessageAsJson(String.format(resources.getString(keyChainAccessError), e.getLocalizedMessage()));
-        } catch (KeyManagementException e) {
-            e.printStackTrace();
-            initError = getErrorMessageAsJson(String.format(resources.getString(keyChainAccessError), e.getLocalizedMessage()));
-        } catch (NoSuchAlgorithmException e) {
-            e.printStackTrace();
-            initError = getErrorMessageAsJson(resources.getString(error_no_such_algorithm_exception_user_message));
-        } catch (CertificateException e) {
-            e.printStackTrace();
-            initError = getErrorMessageAsJson(resources.getString(certificate_error));
-        } catch (UnknownHostException e) {
-            e.printStackTrace();
-            initError = getErrorMessageAsJson(resources.getString(server_unreachable_message));
-        } catch (IOException e) {
-            e.printStackTrace();
-            initError = getErrorMessageAsJson(resources.getString(error_io_exception_user_message));
-        } catch (NoSuchProviderException e) {
-            e.printStackTrace();
-            initError = getErrorMessageAsJson(resources.getString(error_no_such_algorithm_exception_user_message));
-        }
-        return null;
-    }
-    private OkHttpClient initCommercialCAHttpClient(JSONObject initError) {
-        return initHttpClient(initError, false);
-    }
-
-    private OkHttpClient initSelfSignedCAHttpClient(JSONObject initError) {
-        return initHttpClient(initError, true);
-    }
-
-    @NonNull
-    private ConnectionSpec getConnectionSpec() {
-        ConnectionSpec.Builder connectionSpecbuilder = new ConnectionSpec.Builder(ConnectionSpec.MODERN_TLS)
-                .tlsVersions(TlsVersion.TLS_1_2, TlsVersion.TLS_1_3);
-        //FIXME: restrict connection further to the following recommended cipher suites for ALL supported API levels
-        //figure out how to use bcjsse for that purpose
-        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.LOLLIPOP_MR1)
-            connectionSpecbuilder.cipherSuites(
-                    CipherSuite.TLS_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256,
-                    CipherSuite.TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256,
-                    CipherSuite.TLS_ECDHE_ECDSA_WITH_AES_256_GCM_SHA384,
-                    CipherSuite.TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384,
-                    CipherSuite.TLS_ECDHE_ECDSA_WITH_CHACHA20_POLY1305_SHA256,
-                    CipherSuite.TLS_ECDHE_RSA_WITH_CHACHA20_POLY1305_SHA256
-            );
-        return connectionSpecbuilder.build();
-    }
-
-    @NonNull
-    private CookieJar getCookieJar() {
-        return new CookieJar() {
-            private final HashMap<String, List<Cookie>> cookieStore = new HashMap<>();
-
-            @Override
-            public void saveFromResponse(HttpUrl url, List<Cookie> cookies) {
-                cookieStore.put(url.host(), cookies);
-            }
-
-            @Override
-            public List<Cookie> loadForRequest(HttpUrl url) {
-                List<Cookie> cookies = cookieStore.get(url.host());
-                return cookies != null ? cookies : new ArrayList<Cookie>();
-            }
-        };
-    }
-
-
-    private Bundle tryToRegister(Bundle task) {
-        Bundle result = new Bundle();
-        int progress = 0;
-
-        String username = User.userName();
-        String password = task.getString(SessionDialog.PASSWORD);
-
-        if (validUserLoginData(username, password)) {
-            result = register(username, password);
-            broadcastProgress(progress++);
-        } else {
-            if (!wellFormedPassword(password)) {
-                result.putBoolean(RESULT_KEY, false);
-                result.putString(SessionDialog.USERNAME, username);
-                result.putBoolean(SessionDialog.ERRORS.PASSWORD_INVALID_LENGTH.toString(), true);
-            }
-            if (!validUsername(username)) {
-                result.putBoolean(RESULT_KEY, false);
-                result.putBoolean(SessionDialog.ERRORS.USERNAME_MISSING.toString(), true);
-            }
-        }
-
-        return result;
-    }
-
-    private Bundle register(String username, String password) {
-        JSONObject stepResult = null;
-        OkHttpClient okHttpClient = initSelfSignedCAHttpClient(stepResult);
-        if (okHttpClient == null) {
-            return authFailedNotification(stepResult, username);
-        }
-
-        LeapSRPSession client = new LeapSRPSession(username, password);
-        byte[] salt = client.calculateNewSalt();
-
-        BigInteger password_verifier = client.calculateV(username, password, salt);
-
-        JSONObject api_result = sendNewUserDataToSRPServer(provider_api_url, username, new BigInteger(1, salt).toString(16), password_verifier.toString(16), okHttpClient);
-
-        Bundle result = new Bundle();
-        if (api_result.has(ERRORS))
-            result = authFailedNotification(api_result, username);
-        else {
-            result.putString(SessionDialog.USERNAME, username);
-            result.putString(SessionDialog.PASSWORD, password);
-            result.putBoolean(RESULT_KEY, true);
-        }
-
-        return result;
-    }
-
-    /**
-     * Starts the authentication process using SRP protocol.
-     *
-     * @param task containing: username, password and api url.
-     * @return a bundle with a boolean value mapped to a key named RESULT_KEY, and which is true if authentication was successful.
-     */
-    private Bundle tryToAuthenticate(Bundle task) {
-        Bundle result = new Bundle();
-        int progress = 0;
-
-        String username = User.userName();
-        String password = task.getString(SessionDialog.PASSWORD);
-        if (validUserLoginData(username, password)) {
-            result = authenticate(username, password);
-            broadcastProgress(progress++);
-        } else {
-            if (!wellFormedPassword(password)) {
-                result.putBoolean(RESULT_KEY, false);
-                result.putString(SessionDialog.USERNAME, username);
-                result.putBoolean(SessionDialog.ERRORS.PASSWORD_INVALID_LENGTH.toString(), true);
-            }
-            if (!validUsername(username)) {
-                result.putBoolean(RESULT_KEY, false);
-                result.putBoolean(SessionDialog.ERRORS.USERNAME_MISSING.toString(), true);
-            }
-        }
-
-        return result;
-    }
-
-    private Bundle authenticate(String username, String password) {
-        Bundle result = new Bundle();
-        JSONObject stepResult = new JSONObject();
-        OkHttpClient okHttpClient = initSelfSignedCAHttpClient(stepResult);
-        if (okHttpClient == null) {
-            return authFailedNotification(stepResult, username);
-        }
-
-        LeapSRPSession client = new LeapSRPSession(username, password);
-        byte[] A = client.exponential();
-
-        JSONObject step_result = sendAToSRPServer(provider_api_url, username, new BigInteger(1, A).toString(16), okHttpClient);
-        try {
-            String salt = step_result.getString(LeapSRPSession.SALT);
-            byte[] Bbytes = new BigInteger(step_result.getString("B"), 16).toByteArray();
-            byte[] M1 = client.response(new BigInteger(salt, 16).toByteArray(), Bbytes);
-            if (M1 != null) {
-                step_result = sendM1ToSRPServer(provider_api_url, username, M1, okHttpClient);
-                setTokenIfAvailable(step_result);
-                byte[] M2 = new BigInteger(step_result.getString(LeapSRPSession.M2), 16).toByteArray();
-                if (client.verify(M2)) {
-                    result.putBoolean(RESULT_KEY, true);
-                } else {
-                    authFailedNotification(step_result, username);
-                }
-            } else {
-                result.putBoolean(RESULT_KEY, false);
-                result.putString(SessionDialog.USERNAME, username);
-                result.putString(resources.getString(R.string.user_message), resources.getString(R.string.error_srp_math_error_user_message));
-            }
-        } catch (JSONException e) {
-            result = authFailedNotification(step_result, username);
-            e.printStackTrace();
-        }
-
-        return result;
-    }
-
-    private boolean setTokenIfAvailable(JSONObject authentication_step_result) {
-        try {
-            LeapSRPSession.setToken(authentication_step_result.getString(LeapSRPSession.TOKEN));
-        } catch (JSONException e) { //
-            return false;
-        }
-        return true;
-    }
-
-    private Bundle authFailedNotification(JSONObject result, String username) {
-        Bundle userNotificationBundle = new Bundle();
-        Object baseErrorMessage = result.opt(ERRORS);
-        if (baseErrorMessage != null) {
-            if (baseErrorMessage instanceof JSONObject) {
-                try {
-                    JSONObject errorMessage = result.getJSONObject(ERRORS);
-                    String errorType = errorMessage.keys().next().toString();
-                    String message = errorMessage.get(errorType).toString();
-                    userNotificationBundle.putString(resources.getString(R.string.user_message), message);
-                } catch (JSONException e) {
-                    e.printStackTrace();
-                }
-            } else if (baseErrorMessage instanceof String) {
-                try {
-                    String errorMessage = result.getString(ERRORS);
-                    userNotificationBundle.putString(resources.getString(R.string.user_message), errorMessage);
-                } catch (JSONException e) {
-                    e.printStackTrace();
-                }
-            }
-        }
-
-        if (!username.isEmpty())
-            userNotificationBundle.putString(SessionDialog.USERNAME, username);
-        userNotificationBundle.putBoolean(RESULT_KEY, false);
-
-        return userNotificationBundle;
-    }
-
-    /**
-     * Sets up an intent with the progress value passed as a parameter
-     * and sends it as a broadcast.
-     *
-     * @param progress
-     */
-    private void broadcastProgress(int progress) {
-        Intent intentUpdate = new Intent();
-        intentUpdate.setAction(UPDATE_PROGRESSBAR);
-        intentUpdate.addCategory(Intent.CATEGORY_DEFAULT);
-        intentUpdate.putExtra(CURRENT_PROGRESS, progress);
-        sendBroadcast(intentUpdate);
-    }
-
-    /**
-     * Validates parameters entered by the user to log in
-     *
-     * @param username
-     * @param password
-     * @return true if both parameters are present and the entered password length is greater or equal to eight (8).
-     */
-    private boolean validUserLoginData(String username, String password) {
-        return validUsername(username) && wellFormedPassword(password);
-    }
-
-    private boolean validUsername(String username) {
-        return username != null && !username.isEmpty();
-    }
-
-    /**
-     * Validates a password
-     *
-     * @param password
-     * @return true if the entered password length is greater or equal to eight (8).
-     */
-    private boolean wellFormedPassword(String password) {
-        return password != null && password.length() >= 8;
-    }
-
-    /**
-     * Sends an HTTP POST request to the authentication server with the SRP Parameter A.
-     *
-     * @param server_url
-     * @param username
-     * @param clientA    First SRP parameter sent
-     * @param okHttpClient
-     * @return response from authentication server
-     */
-    private JSONObject sendAToSRPServer(String server_url, String username, String clientA, OkHttpClient okHttpClient) {
-        SrpCredentials srpCredentials = new SrpCredentials(username, clientA);
-        return sendToServer(server_url + "/sessions.json", "POST", srpCredentials.toString(), okHttpClient);
-    }
-
-    /**
-     * Sends an HTTP PUT request to the authentication server with the SRP Parameter M1 (or simply M).
-     *
-     * @param server_url
-     * @param username
-     * @param m1         Second SRP parameter sent
-     * @param okHttpClient
-     * @return response from authentication server
-     */
-    private JSONObject sendM1ToSRPServer(String server_url, String username, byte[] m1, OkHttpClient okHttpClient) {
-        String m1json = "{\"client_auth\":\"" + new BigInteger(1, ConfigHelper.trim(m1)).toString(16)+ "\"}";
-        return sendToServer(server_url + "/sessions/" + username + ".json", "PUT", m1json, okHttpClient);
-    }
-
-    /**
-     * Sends an HTTP POST request to the api server to register a new user.
-     *
-     * @param server_url
-     * @param username
-     * @param salt
-     * @param password_verifier
-     * @param okHttpClient
-     * @return response from authentication server
-     */
-    private JSONObject sendNewUserDataToSRPServer(String server_url, String username, String salt, String password_verifier, OkHttpClient okHttpClient) {
-        return sendToServer(server_url + "/users.json", "POST", new SrpRegistrationData(username, salt, password_verifier).toString(), okHttpClient);
-    }
-
-    /**
-     * Executes an HTTP request expecting a JSON response.
-     *
-     * @param url
-     * @param request_method
-     * @return response from authentication server
-     */
-    private JSONObject sendToServer(String url, String request_method, String jsonString, OkHttpClient okHttpClient) {
-        return requestJsonFromServer(url, request_method, jsonString, null, okHttpClient);
-    }
-
-    private String sendGetStringToServer(String url, List<Pair<String, String>> headerArgs, OkHttpClient okHttpClient) {
-        return requestStringFromServer(url, "GET", null, headerArgs, okHttpClient);
-    }
-
-
-
-    private JSONObject requestJsonFromServer(String url, String request_method, String jsonString, List<Pair<String, String>> headerArgs, @NonNull OkHttpClient okHttpClient)  {
-        JSONObject responseJson;
-        String plain_response = requestStringFromServer(url, request_method, jsonString, headerArgs, okHttpClient);
-
-        try {
-            responseJson = new JSONObject(plain_response);
-        } catch (JSONException e) {
-            e.printStackTrace();
-            responseJson = getErrorMessageAsJson(error_json_exception_user_message);
-        }
-        return responseJson;
-
-    }
-
-    private String requestStringFromServer(String url, String request_method, String jsonString, List<Pair<String, String>> headerArgs, @NonNull OkHttpClient okHttpClient) {
-        Response response;
-        String plainResponseBody = null;
-
-        RequestBody jsonBody = jsonString != null ? RequestBody.create(JSON, jsonString) : null;
-        Request.Builder requestBuilder = new Request.Builder()
-                .url(url)
-                .method(request_method, jsonBody);
-        if (headerArgs != null) {
-            for (Pair<String, String> keyValPair : headerArgs) {
-                requestBuilder.addHeader(keyValPair.first, keyValPair.second);
-            }
-        }
-        //TODO: move to getHeaderArgs()?
-        String locale = Locale.getDefault().getLanguage() + Locale.getDefault().getCountry();
-        requestBuilder.addHeader("Accept-Language", locale);
-        Request request = requestBuilder.build();
-
-        try {
-            response = okHttpClient.newCall(request).execute();
-
-            InputStream inputStream = response.body().byteStream();
-            Scanner scanner = new Scanner(inputStream).useDelimiter("\\A");
-            if (scanner.hasNext()) {
-                plainResponseBody = scanner.next();
-            }
-
-        } catch (NullPointerException npe) {
-            plainResponseBody = formatErrorMessage(error_json_exception_user_message);
-        } catch (UnknownHostException e) {
-            plainResponseBody = formatErrorMessage(server_unreachable_message);
-        } catch (MalformedURLException e) {
-            plainResponseBody = formatErrorMessage(malformed_url);
-        } catch (SocketTimeoutException e) {
-            plainResponseBody = formatErrorMessage(server_unreachable_message);
-        } catch (SSLHandshakeException e) {
-            plainResponseBody = formatErrorMessage(certificate_error);
-        } catch (ConnectException e) {
-            plainResponseBody = formatErrorMessage(service_is_down_error);
-        } catch (IllegalArgumentException e) {
-            plainResponseBody = formatErrorMessage(error_no_such_algorithm_exception_user_message);
-        } catch (UnknownServiceException e) {
-            //unable to find acceptable protocols - tlsv1.2 not enabled?
-            plainResponseBody = formatErrorMessage(error_no_such_algorithm_exception_user_message);
-        } catch (IOException e) {
-            plainResponseBody = formatErrorMessage(error_io_exception_user_message);
-        }
-
-        return plainResponseBody;
-    }
+public class ProviderAPI extends ProviderApiBase {
 
     /**
      * Downloads a provider.json from a given URL, adding a new provider using the given name.
@@ -667,7 +58,8 @@ public class ProviderAPI extends IntentService {
      * @param task containing a boolean meaning if the provider is custom or not, another boolean meaning if the user completely trusts this provider, the provider name and its provider.json url.
      * @return a bundle with a boolean value mapped to a key named RESULT_KEY, and which is true if the update was successful.
      */
-    private Bundle setUpProvider(Bundle task) {
+    @Override
+    protected Bundle setUpProvider(Bundle task) {
         int progress = 0;
         Bundle current_download = new Bundle();
 
@@ -705,77 +97,6 @@ public class ProviderAPI extends IntentService {
         return current_download;
     }
 
-    private Bundle downloadCACert() {
-        Bundle result = new Bundle();
-        try {
-            JSONObject provider_json = new JSONObject(preferences.getString(Provider.KEY, ""));
-            String ca_cert_url = provider_json.getString(Provider.CA_CERT_URI);
-            String cert_string = downloadWithCommercialCA(ca_cert_url);
-            result.putBoolean(RESULT_KEY, true);
-
-            if (validCertificate(cert_string) && go_ahead) {
-                preferences.edit().putString(Provider.CA_CERT, cert_string).commit();
-                result.putBoolean(RESULT_KEY, true);
-            } else {
-                String reason_to_fail = pickErrorMessage(cert_string);
-                result.putString(ERRORS, reason_to_fail);
-                result.putBoolean(RESULT_KEY, false);
-            }
-        } catch (JSONException e) {
-            String reason_to_fail = formatErrorMessage(malformed_url);
-            result.putString(ERRORS, reason_to_fail);
-            result.putBoolean(RESULT_KEY, false);
-        }
-
-        return result;
-    }
-
-
-    public static boolean caCertDownloaded() {
-        return CA_CERT_DOWNLOADED;
-    }
-
-    private boolean validCertificate(String cert_string) {
-        boolean result = false;
-        if (!ConfigHelper.checkErroneousDownload(cert_string)) {
-            X509Certificate certificate = ConfigHelper.parseX509CertificateFromString(cert_string);
-            try {
-                if (certificate != null) {
-                    JSONObject provider_json = new JSONObject(preferences.getString(Provider.KEY, ""));
-                    String fingerprint = provider_json.getString(Provider.CA_CERT_FINGERPRINT);
-                    String encoding = fingerprint.split(":")[0];
-                    String expected_fingerprint = fingerprint.split(":")[1];
-                    String real_fingerprint = base64toHex(Base64.encodeToString(
-                            MessageDigest.getInstance(encoding).digest(certificate.getEncoded()),
-                            Base64.DEFAULT));
-
-                    result = real_fingerprint.trim().equalsIgnoreCase(expected_fingerprint.trim());
-                } else
-                    result = false;
-            } catch (JSONException e) {
-                result = false;
-            } catch (NoSuchAlgorithmException e) {
-                result = false;
-            } catch (CertificateEncodingException e) {
-                result = false;
-            }
-        }
-
-        return result;
-    }
-
-    private String base64toHex(String base64_input) {
-        byte[] byteArray = Base64.decode(base64_input, Base64.DEFAULT);
-        int readBytes = byteArray.length;
-        StringBuffer hexData = new StringBuffer();
-        int onebyte;
-        for (int i = 0; i < readBytes; i++) {
-            onebyte = ((0x000000ff & byteArray[i]) | 0xffffff00);
-            hexData.append(Integer.toHexString(onebyte).substring(6));
-        }
-        return hexData.toString();
-    }
-
     private Bundle getAndSetProviderJson(String provider_main_url, String provider_ca_cert_fingerprint) {
         Bundle result = new Bundle();
 
@@ -807,7 +128,12 @@ public class ProviderAPI extends IntentService {
         return result;
     }
 
-    private Bundle getAndSetEipServiceJson() {
+    /**
+     * Downloads the eip-service.json from a given URL, and saves eip service capabilities including the offered gateways
+     * @return a bundle with a boolean value mapped to a key named RESULT_KEY, and which is true if the download was successful.
+     */
+    @Override
+    protected Bundle getAndSetEipServiceJson() {
         Bundle result = new Bundle();
         String eip_service_json_string = "";
         if (go_ahead) {
@@ -831,23 +157,58 @@ public class ProviderAPI extends IntentService {
     }
 
     /**
-     * Interprets the error message as a JSON object and extract the "errors" keyword pair.
-     * If the error message is not a JSON object, then it is returned untouched.
+     * Downloads a new OpenVPN certificate, attaching authenticated cookie for authenticated certificate.
      *
-     * @param string_json_error_message
-     * @return final error message
+     * @return true if certificate was downloaded correctly, false if provider.json is not present in SharedPreferences, or if the certificate url could not be parsed as a URI, or if there was an SSL error.
      */
-    private String pickErrorMessage(String string_json_error_message) {
-        String error_message = "";
+    @Override
+    protected boolean updateVpnCertificate() {
         try {
-            JSONObject json_error_message = new JSONObject(string_json_error_message);
-            error_message = json_error_message.getString(ERRORS);
+            JSONObject provider_json = new JSONObject(preferences.getString(Provider.KEY, ""));
+
+            String provider_main_url = provider_json.getString(Provider.API_URL);
+            URL new_cert_string_url = new URL(provider_main_url + "/" + provider_json.getString(Provider.API_VERSION) + "/" + Constants.VPN_CERTIFICATE);
+
+            String cert_string = downloadWithProviderCA(new_cert_string_url.toString());
+
+            if (cert_string.isEmpty() || ConfigHelper.checkErroneousDownload(cert_string))
+                return false;
+            else
+                return loadCertificate(cert_string);
+        } catch (IOException e) {
+            // TODO Auto-generated catch block
+            e.printStackTrace();
+            return false;
         } catch (JSONException e) {
             // TODO Auto-generated catch block
-            error_message = string_json_error_message;
+            e.printStackTrace();
+            return false;
+        }
+    }
+
+    private Bundle downloadCACert() {
+        Bundle result = new Bundle();
+        try {
+            JSONObject provider_json = new JSONObject(preferences.getString(Provider.KEY, ""));
+            String ca_cert_url = provider_json.getString(Provider.CA_CERT_URI);
+            String cert_string = downloadWithCommercialCA(ca_cert_url);
+            result.putBoolean(RESULT_KEY, true);
+
+            if (validCertificate(cert_string) && go_ahead) {
+                preferences.edit().putString(Provider.CA_CERT, cert_string).commit();
+                result.putBoolean(RESULT_KEY, true);
+            } else {
+                String reason_to_fail = pickErrorMessage(cert_string);
+                result.putString(ERRORS, reason_to_fail);
+                result.putBoolean(RESULT_KEY, false);
+            }
+        } catch (JSONException e) {
+            String reason_to_fail = formatErrorMessage(malformed_url);
+            result.putString(ERRORS, reason_to_fail);
+            result.putBoolean(RESULT_KEY, false);
         }
 
-        return error_message;
+        return result;
     }
 
     //TODO: refactor with ticket #8773
@@ -861,7 +222,7 @@ public class ProviderAPI extends IntentService {
             HttpsURLConnection connection = PinningHelper.getPinnedHttpsURLConnection(Dashboard.getContext(), pins, url);
             connection.setConnectTimeout(seconds_of_timeout * 1000);
             if (!LeapSRPSession.getToken().isEmpty())
-                connection.addRequestProperty(LeapSRPSession.AUTHORIZATION_HEADER, "Token token = " + LeapSRPSession.getToken());
+                connection.addRequestProperty(LeapSRPSession.AUTHORIZATION_HEADER, "Token token=" + LeapSRPSession.getToken());
             result = new Scanner(connection.getInputStream()).useDelimiter("\\A").next();
         } catch (IOException e) {
             if(e instanceof SSLHandshakeException)
@@ -879,8 +240,7 @@ public class ProviderAPI extends IntentService {
      * @param string_url
      * @return
      */
-    private String downloadWithCommercialCA(String string_url) {
-
+    protected String downloadWithCommercialCA(String string_url) {
         String responseString;
         JSONObject errorJson = new JSONObject();
 
@@ -908,24 +268,13 @@ public class ProviderAPI extends IntentService {
         return responseString;
     }
 
-
-    @NonNull
-    private List<Pair<String, String>> getAuthorizationHeader() {
-        List<Pair<String, String>> headerArgs = new ArrayList<>();
-        if (!LeapSRPSession.getToken().isEmpty()) {
-            Pair<String, String> authorizationHeaderPair = new Pair<>(LeapSRPSession.AUTHORIZATION_HEADER, "Token token=" + LeapSRPSession.getToken());
-            headerArgs.add(authorizationHeaderPair);
-        }
-        return headerArgs;
-    }
-
     /**
      * Tries to download the contents of the provided url using not commercially validated CA certificate from chosen provider.
      *
      * @param urlString as a string
      * @return an empty string if it fails, the url content if not.
      */
-    private String downloadWithProviderCA(String urlString) {
+    protected String downloadWithProviderCA(String urlString) {
         JSONObject initError = new JSONObject();
         String responseString;
 
@@ -941,89 +290,4 @@ public class ProviderAPI extends IntentService {
         return responseString;
     }
 
-    private boolean logOut() {
-        OkHttpClient okHttpClient = initSelfSignedCAHttpClient(new JSONObject());
-        if (okHttpClient == null) {
-            return false;
-        }
-
-        String deleteUrl = provider_api_url + "/logout";
-        int progress = 0;
-
-        Request.Builder requestBuilder = new Request.Builder()
-                .url(deleteUrl)
-                .delete();
-        Request request = requestBuilder.build();
-
-        try {
-            Response response = okHttpClient.newCall(request).execute();
-                                            // v---- was already not authorized
-            if (response.isSuccessful() || response.code() == 401) {
-                broadcastProgress(progress++);
-                LeapSRPSession.setToken("");
-            }
-
-        } catch (IOException e) {
-            return false;
-        }
-        return true;
-    }
-
-    /**
-     * Downloads a new OpenVPN certificate, attaching authenticated cookie for authenticated certificate.
-     *
-     * @return true if certificate was downloaded correctly, false if provider.json is not present in SharedPreferences, or if the certificate url could not be parsed as a URI, or if there was an SSL error.
-     */
-    private boolean updateVpnCertificate() {
-        try {
-            JSONObject provider_json = new JSONObject(preferences.getString(Provider.KEY, ""));
-
-            String provider_main_url = provider_json.getString(Provider.API_URL);
-            URL new_cert_string_url = new URL(provider_main_url + "/" + provider_json.getString(Provider.API_VERSION) + "/" + Constants.VPN_CERTIFICATE);
-
-            String cert_string = downloadWithProviderCA(new_cert_string_url.toString());
-
-            if (cert_string.isEmpty() || ConfigHelper.checkErroneousDownload(cert_string))
-                return false;
-            else
-                return loadCertificate(cert_string);
-        } catch (IOException e) {
-            // TODO Auto-generated catch block
-            e.printStackTrace();
-            return false;
-        } catch (JSONException e) {
-            // TODO Auto-generated catch block
-            e.printStackTrace();
-            return false;
-        }
-    }
-
-    //FIXME: don't save private keys in shared preferences! use the keystore
-    private boolean loadCertificate(String cert_string) {
-        try {
-            // API returns concatenated cert & key.  Split them for OpenVPN options
-            String certificateString = null, keyString = null;
-            String[] certAndKey = cert_string.split("(?<=-\n)");
-            for (int i = 0; i < certAndKey.length - 1; i++) {
-                if (certAndKey[i].contains("KEY")) {
-                    keyString = certAndKey[i++] + certAndKey[i];
-                } else if (certAndKey[i].contains("CERTIFICATE")) {
-                    certificateString = certAndKey[i++] + certAndKey[i];
-                }
-            }
-
-            RSAPrivateKey key = ConfigHelper.parseRsaKeyFromString(keyString);
-            keyString = Base64.encodeToString(key.getEncoded(), Base64.DEFAULT);
-            preferences.edit().putString(Constants.PRIVATE_KEY, "-----BEGIN RSA PRIVATE KEY-----\n" + keyString + "-----END RSA PRIVATE KEY-----").commit();
-
-            X509Certificate certificate = ConfigHelper.parseX509CertificateFromString(certificateString);
-            certificateString = Base64.encodeToString(certificate.getEncoded(), Base64.DEFAULT);
-            preferences.edit().putString(Constants.VPN_CERTIFICATE, "-----BEGIN CERTIFICATE-----\n" + certificateString + "-----END CERTIFICATE-----").commit();
-            return true;
-        } catch (CertificateException e) {
-            // TODO Auto-generated catch block
-            e.printStackTrace();
-            return false;
-        }
-    }
 }