Merge branch 'feature/rebrand-as-bitmask' into develop

1 files changed, 780 insertions, 0 deletions

diff --git a/src/se/leap/bitmaskclient/ProviderAPI.java b/src/se/leap/bitmaskclient/ProviderAPI.java
new file mode 100644
index 00000000..39b44e24
--- /dev/null
+++ b/src/se/leap/bitmaskclient/ProviderAPI.java
@@ -0,0 +1,780 @@
+/**
+ * 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;
+
+import java.io.DataOutputStream;
+import java.io.FileNotFoundException;
+import java.io.IOException;
+import java.io.InputStream;
+import java.io.UnsupportedEncodingException;
+import java.math.BigInteger;
+import java.net.CookieHandler;
+import java.net.CookieManager;
+import java.net.CookiePolicy;
+import java.net.MalformedURLException;
+import java.net.SocketTimeoutException;
+import java.net.URL;
+import java.net.URLConnection;
+import java.net.URLEncoder;
+import java.net.UnknownHostException;
+import java.security.KeyManagementException;
+import java.security.KeyStore;
+import java.security.KeyStoreException;
+import java.security.NoSuchAlgorithmException;
+import java.security.SecureRandom;
+import java.security.cert.CertificateException;
+import java.security.cert.X509Certificate;
+import java.security.interfaces.RSAPrivateKey;
+import java.util.HashMap;
+import java.util.Iterator;
+import java.util.Map;
+import java.util.Scanner;
+
+import javax.net.ssl.HostnameVerifier;
+import javax.net.ssl.HttpsURLConnection;
+import javax.net.ssl.KeyManager;
+import javax.net.ssl.SSLContext;
+import javax.net.ssl.SSLSession;
+import javax.net.ssl.TrustManager;
+import javax.net.ssl.TrustManagerFactory;
+import javax.net.ssl.X509TrustManager;
+
+import org.apache.http.client.ClientProtocolException;
+import org.jboss.security.srp.SRPParameters;
+import org.json.JSONException;
+import org.json.JSONObject;
+
+import se.leap.bitmaskclient.R;
+import se.leap.bitmaskclient.ProviderListContent.ProviderItem;
+import android.app.IntentService;
+import android.content.Intent;
+import android.os.Bundle;
+import android.os.Handler;
+import android.os.ResultReceiver;
+import android.util.Base64;
+import android.util.Log;
+import android.widget.Toast;
+
+/**
+ * Implements HTTP api methods used to manage communications with the provider server.
+ * 
+ * It's an IntentService because it downloads data from the Internet, so it operates in the background.
+ *  
+ * @author parmegv
+ * @author MeanderingCode
+ *
+ */
+public class ProviderAPI extends IntentService {
+	
+	private Handler mHandler;
+
+    final public static String
+    DOWNLOAD_JSON_FILES_BUNDLE_EXTRA = "downloadJSONFiles",	
+    UPDATE_PROVIDER_DOTJSON = "updateProviderDotJSON",
+    DOWNLOAD_NEW_PROVIDER_DOTJSON = "downloadNewProviderDotJSON",
+    SRP_REGISTER = "srpRegister",
+    SRP_AUTH = "srpAuth",
+    LOG_OUT = "logOut",
+    DOWNLOAD_CERTIFICATE = "downloadUserAuthedCertificate",
+    PARAMETERS = "parameters",
+    RESULT_KEY = "result",
+    RECEIVER_KEY = "receiver",
+    SESSION_ID_COOKIE_KEY = "session_id_cookie_key",
+    SESSION_ID_KEY = "session_id",
+    ERRORS = "errors"
+    ;
+
+    final public static int
+    CUSTOM_PROVIDER_ADDED = 0,
+    CORRECTLY_DOWNLOADED_JSON_FILES = 1,
+    INCORRECTLY_DOWNLOADED_JSON_FILES = 2,
+    SRP_AUTHENTICATION_SUCCESSFUL = 3,
+    SRP_AUTHENTICATION_FAILED = 4,
+    SRP_REGISTRATION_SUCCESSFUL = 5,
+    SRP_REGISTRATION_FAILED = 6,
+    LOGOUT_SUCCESSFUL = 7,
+    LOGOUT_FAILED = 8,
+    CORRECTLY_DOWNLOADED_CERTIFICATE = 9,
+    INCORRECTLY_DOWNLOADED_CERTIFICATE = 10,
+    CORRECTLY_UPDATED_PROVIDER_DOT_JSON = 11,
+    INCORRECTLY_UPDATED_PROVIDER_DOT_JSON = 12,
+    CORRECTLY_DOWNLOADED_ANON_CERTIFICATE = 13,
+    INCORRECTLY_DOWNLOADED_ANON_CERTIFICATE = 14
+    ;
+
+	public ProviderAPI() {
+		super("ProviderAPI");
+		Log.v("ClassName", "Provider API");
+	}
+	
+	@Override
+	public void onCreate() {
+		super.onCreate();
+		mHandler = new Handler();
+		CookieHandler.setDefault(new CookieManager(null, CookiePolicy.ACCEPT_ORIGINAL_SERVER) );
+	}
+	
+	private void displayToast(final int toast_string_id) {
+		mHandler.post(new Runnable() {
+			
+			@Override
+			public void run() {
+	            Toast.makeText(ProviderAPI.this, toast_string_id, Toast.LENGTH_LONG).show();                
+			}
+		});
+	}
+
+	@Override
+	protected void onHandleIntent(Intent command) {
+		final ResultReceiver receiver = command.getParcelableExtra("receiver");
+		String action = command.getAction();
+		Bundle parameters = command.getBundleExtra(PARAMETERS);
+		
+		if(action.equalsIgnoreCase(DOWNLOAD_JSON_FILES_BUNDLE_EXTRA)) {
+			if(!downloadJsonFiles(parameters)) {
+				receiver.send(INCORRECTLY_DOWNLOADED_JSON_FILES, Bundle.EMPTY);
+			} else { 
+				receiver.send(CORRECTLY_DOWNLOADED_JSON_FILES, Bundle.EMPTY);
+			}
+		} else if(action.equalsIgnoreCase(UPDATE_PROVIDER_DOTJSON)) {
+			Bundle result = updateProviderDotJSON(parameters);
+			if(result.getBoolean(RESULT_KEY)) {
+				receiver.send(CORRECTLY_UPDATED_PROVIDER_DOT_JSON, result);
+			} else { 
+				receiver.send(INCORRECTLY_UPDATED_PROVIDER_DOT_JSON, Bundle.EMPTY);
+			}
+		} else if (action.equalsIgnoreCase(DOWNLOAD_NEW_PROVIDER_DOTJSON)) {
+			Bundle result = downloadNewProviderDotJSON(parameters);
+			if(result.getBoolean(RESULT_KEY)) {
+				receiver.send(CORRECTLY_UPDATED_PROVIDER_DOT_JSON, result);
+			} else {
+				receiver.send(INCORRECTLY_DOWNLOADED_JSON_FILES, Bundle.EMPTY);
+			}
+		} else if (action.equalsIgnoreCase(SRP_AUTH)) {
+			Bundle session_id_bundle = authenticateBySRP(parameters);
+			if(session_id_bundle.getBoolean(RESULT_KEY)) {
+				receiver.send(SRP_AUTHENTICATION_SUCCESSFUL, session_id_bundle);
+			} else {
+				receiver.send(SRP_AUTHENTICATION_FAILED, session_id_bundle);
+			}
+		} else if (action.equalsIgnoreCase(LOG_OUT)) {
+			if(logOut(parameters)) {
+				receiver.send(LOGOUT_SUCCESSFUL, Bundle.EMPTY);
+			} else {
+				receiver.send(LOGOUT_FAILED, Bundle.EMPTY);
+			}
+		} else if (action.equalsIgnoreCase(DOWNLOAD_CERTIFICATE)) {
+			if(getNewCert(parameters)) {
+				receiver.send(CORRECTLY_DOWNLOADED_CERTIFICATE, Bundle.EMPTY);
+			} else {
+				receiver.send(INCORRECTLY_DOWNLOADED_CERTIFICATE, Bundle.EMPTY);
+			}
+		}
+	}
+
+	/**
+	 * Downloads the main cert and the eip-service.json files given through the task parameter
+	 * @param task
+	 * @return true if eip-service.json was parsed as a JSON object correctly.
+	 */
+	private boolean downloadJsonFiles(Bundle task) {
+		String cert_url = task.getString(Provider.CA_CERT);
+		String eip_service_json_url = task.getString(EIP.KEY);
+		boolean danger_on = task.getBoolean(ProviderItem.DANGER_ON);
+		try {
+			String cert_string = downloadWithCommercialCA(cert_url, danger_on);
+			if(cert_string.isEmpty()) return false;
+			X509Certificate certCert = ConfigHelper.parseX509CertificateFromString(cert_string);
+			cert_string = Base64.encodeToString( certCert.getEncoded(), Base64.DEFAULT);
+			ConfigHelper.saveSharedPref(Provider.CA_CERT, "-----BEGIN CERTIFICATE-----\n"+cert_string+"-----END CERTIFICATE-----");
+			
+			String eip_service_string = downloadWithCommercialCA(eip_service_json_url, danger_on);
+			ConfigHelper.saveSharedPref(EIP.KEY, new JSONObject(eip_service_string));
+			
+			return true;
+		} catch (JSONException e) {
+			return false;
+		} catch (CertificateException e) {
+			// TODO Auto-generated catch block
+			e.printStackTrace();
+			return false;
+		}
+	}
+	
+	/**
+	 * 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 authenticateBySRP(Bundle task) {
+		Bundle session_id_bundle = new Bundle();
+		
+		String username = (String) task.get(LogInDialog.USERNAME);
+		String password = (String) task.get(LogInDialog.PASSWORD);
+		if(validUserLoginData(username, password)) {
+			String authentication_server = (String) task.get(Provider.API_URL);
+
+			SRPParameters params = new SRPParameters(new BigInteger(ConfigHelper.NG_1024, 16).toByteArray(), ConfigHelper.G.toByteArray(), BigInteger.ZERO.toByteArray(), "SHA-256");
+			LeapSRPSession client = new LeapSRPSession(username, password, params);
+			byte[] A = client.exponential();
+			try {
+				JSONObject saltAndB = sendAToSRPServer(authentication_server, username, new BigInteger(1, A).toString(16));
+				if(saltAndB.length() > 0) {
+					String salt = saltAndB.getString(LeapSRPSession.SALT);
+					byte[] Bbytes = new BigInteger(saltAndB.getString("B"), 16).toByteArray();
+					byte[] M1 = client.response(new BigInteger(salt, 16).toByteArray(), Bbytes);
+					JSONObject session_idAndM2 = sendM1ToSRPServer(authentication_server, username, M1);
+					if(session_idAndM2.has(LeapSRPSession.M2) && client.verify((byte[])session_idAndM2.get(LeapSRPSession.M2))) {
+						session_id_bundle.putBoolean(RESULT_KEY, true);
+					} else {
+						session_id_bundle.putBoolean(RESULT_KEY, false);
+						session_id_bundle.putString(getResources().getString(R.string.user_message), getResources().getString(R.string.error_bad_user_password_user_message));
+						session_id_bundle.putString(LogInDialog.USERNAME, username);
+					}
+				} else {
+					session_id_bundle.putString(getResources().getString(R.string.user_message), getResources().getString(R.string.error_bad_user_password_user_message));
+					session_id_bundle.putString(LogInDialog.USERNAME, username);
+					session_id_bundle.putBoolean(RESULT_KEY, false);
+				}
+			} catch (ClientProtocolException e) {
+				session_id_bundle.putBoolean(RESULT_KEY, false);
+				session_id_bundle.putString(getResources().getString(R.string.user_message), getResources().getString(R.string.error_client_http_user_message));
+				session_id_bundle.putString(LogInDialog.USERNAME, username);
+			} catch (IOException e) {
+				session_id_bundle.putBoolean(RESULT_KEY, false);
+				session_id_bundle.putString(getResources().getString(R.string.user_message), getResources().getString(R.string.error_io_exception_user_message));
+				session_id_bundle.putString(LogInDialog.USERNAME, username);
+			} catch (JSONException e) {
+				session_id_bundle.putBoolean(RESULT_KEY, false);
+				session_id_bundle.putString(getResources().getString(R.string.user_message), getResources().getString(R.string.error_json_exception_user_message));
+				session_id_bundle.putString(LogInDialog.USERNAME, username);
+			} catch (NoSuchAlgorithmException e) {
+				session_id_bundle.putBoolean(RESULT_KEY, false);
+				session_id_bundle.putString(getResources().getString(R.string.user_message), getResources().getString(R.string.error_no_such_algorithm_exception_user_message));
+				session_id_bundle.putString(LogInDialog.USERNAME, username);
+			} catch (KeyManagementException e) {
+				// TODO Auto-generated catch block
+				e.printStackTrace();
+			} catch (KeyStoreException e) {
+				// TODO Auto-generated catch block
+				e.printStackTrace();
+			} catch (CertificateException e) {
+				// TODO Auto-generated catch block
+				e.printStackTrace();
+			}
+		} else {
+			if(!wellFormedPassword(password)) {
+				session_id_bundle.putBoolean(RESULT_KEY, false);
+				session_id_bundle.putString(LogInDialog.USERNAME, username);
+				session_id_bundle.putBoolean(LogInDialog.PASSWORD_INVALID_LENGTH, true);
+			}
+			if(username.isEmpty()) {
+				session_id_bundle.putBoolean(RESULT_KEY, false);
+				session_id_bundle.putBoolean(LogInDialog.USERNAME_MISSING, true);
+			}
+		}
+		
+		return session_id_bundle;
+	}
+
+	/**
+	 * Validates parameters entered by the user to log in
+	 * @param entered_username
+	 * @param entered_password
+	 * @return true if both parameters are present and the entered password length is greater or equal to eight (8).
+	 */
+	private boolean validUserLoginData(String entered_username, String entered_password) {
+		return !(entered_username.isEmpty()) && wellFormedPassword(entered_password);
+	}
+
+	/**
+	 * Validates a password
+	 * @param entered_password
+	 * @return true if the entered password length is greater or equal to eight (8).
+	 */
+	private boolean wellFormedPassword(String entered_password) {
+		return entered_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 
+	 * @return response from authentication server
+	 * @throws ClientProtocolException
+	 * @throws IOException
+	 * @throws JSONException
+	 * @throws CertificateException 
+	 * @throws NoSuchAlgorithmException 
+	 * @throws KeyStoreException 
+	 * @throws KeyManagementException 
+	 */
+	private JSONObject sendAToSRPServer(String server_url, String username, String clientA) throws ClientProtocolException, IOException, JSONException, KeyManagementException, KeyStoreException, NoSuchAlgorithmException, CertificateException {
+		Map<String, String> parameters = new HashMap<String, String>();
+		parameters.put("login", username);
+		parameters.put("A", clientA);
+		return sendToServer(server_url + "/sessions.json", "POST", parameters);
+		
+		/*HttpPost post = new HttpPost(server_url + "/sessions.json" + "?" + "login=" + username + "&&" + "A=" + clientA);
+		return sendToServer(post);*/
+	}
+
+	/**
+	 * 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 
+	 * @return response from authentication server
+	 * @throws ClientProtocolException
+	 * @throws IOException
+	 * @throws JSONException
+	 * @throws CertificateException 
+	 * @throws NoSuchAlgorithmException 
+	 * @throws KeyStoreException 
+	 * @throws KeyManagementException 
+	 */
+	private JSONObject sendM1ToSRPServer(String server_url, String username, byte[] m1) throws ClientProtocolException, IOException, JSONException, KeyManagementException, KeyStoreException, NoSuchAlgorithmException, CertificateException {
+		Map<String, String> parameters = new HashMap<String, String>();
+		parameters.put("client_auth", new BigInteger(1, ConfigHelper.trim(m1)).toString(16));
+		
+		//HttpPut put = new HttpPut(server_url + "/sessions/" + username +".json" + "?" + "client_auth" + "=" + new BigInteger(1, ConfigHelper.trim(m1)).toString(16));
+		JSONObject json_response = sendToServer(server_url + "/sessions/" + username +".json", "PUT", parameters);
+
+		JSONObject session_idAndM2 = new JSONObject();
+		if(json_response.length() > 0) {
+			byte[] M2_not_trimmed = new BigInteger(json_response.getString(LeapSRPSession.M2), 16).toByteArray();
+			/*Cookie session_id_cookie = LeapHttpClient.getInstance(getApplicationContext()).getCookieStore().getCookies().get(0);
+			session_idAndM2.put(ConfigHelper.SESSION_ID_COOKIE_KEY, session_id_cookie.getName());
+			session_idAndM2.put(ConfigHelper.SESSION_ID_KEY, session_id_cookie.getValue());*/
+			session_idAndM2.put(LeapSRPSession.M2, ConfigHelper.trim(M2_not_trimmed));
+		}
+		return session_idAndM2;
+	}
+	
+	/**
+	 * Executes an HTTP request expecting a JSON response.
+	 * @param url
+	 * @param request_method
+	 * @param parameters
+	 * @return response from authentication server
+	 * @throws IOException
+	 * @throws JSONException
+	 * @throws MalformedURLException 
+	 * @throws CertificateException 
+	 * @throws NoSuchAlgorithmException 
+	 * @throws KeyStoreException 
+	 * @throws KeyManagementException 
+	 */
+	private JSONObject sendToServer(String url, String request_method, Map<String, String> parameters) throws JSONException, MalformedURLException, IOException, KeyManagementException, KeyStoreException, NoSuchAlgorithmException, CertificateException {
+		JSONObject json_response;
+		InputStream is = null;
+		HttpsURLConnection urlConnection = (HttpsURLConnection)new URL(url).openConnection();
+		urlConnection.setRequestMethod(request_method);
+		urlConnection.setChunkedStreamingMode(0);
+		urlConnection.setSSLSocketFactory(getProviderSSLSocketFactory());
+		try {
+			
+			DataOutputStream writer = new DataOutputStream(urlConnection.getOutputStream());
+			writer.writeBytes(formatHttpParameters(parameters));
+			writer.close();
+
+			is = urlConnection.getInputStream();
+			String plain_response = new Scanner(is).useDelimiter("\\A").next();
+			json_response = new JSONObject(plain_response);
+		} finally {
+			InputStream error_stream = urlConnection.getErrorStream();
+			if(error_stream != null) {
+				String error_response = new Scanner(error_stream).useDelimiter("\\A").next();
+				urlConnection.disconnect();
+				Log.d("Error", error_response);
+				json_response = new JSONObject(error_response);
+				if(!json_response.isNull(ERRORS) || json_response.has(ERRORS)) {
+					return new JSONObject();
+				}
+			}
+		}
+
+		return json_response;
+	}
+	
+	private String formatHttpParameters(Map<String, String> parameters) throws UnsupportedEncodingException	{
+	    StringBuilder result = new StringBuilder();
+	    boolean first = true;
+
+		Iterator<String> parameter_iterator = parameters.keySet().iterator();
+		while(parameter_iterator.hasNext()) {
+			if(first)
+				first = false;
+			else
+				result.append("&&");
+			
+			String key = parameter_iterator.next();
+			String value = parameters.get(key);
+
+	        result.append(URLEncoder.encode(key, "UTF-8"));
+	        result.append("=");
+	        result.append(URLEncoder.encode(value, "UTF-8"));
+		}
+
+	    return result.toString();
+	}
+	/**
+	 * Downloads a provider.json from a given URL, adding a new provider using the given name.  
+	 * @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 updateProviderDotJSON(Bundle task) {
+		Bundle result = new Bundle();
+		boolean custom = task.getBoolean(ProviderItem.CUSTOM);
+		boolean danger_on = task.getBoolean(ProviderItem.DANGER_ON);
+		String provider_json_url = task.getString(Provider.DOT_JSON_URL);
+		String provider_name = task.getString(Provider.NAME);
+		
+		try {
+			String provider_dot_json_string = downloadWithCommercialCA(provider_json_url, danger_on);
+			if(provider_dot_json_string.isEmpty()) {
+				result.putBoolean(RESULT_KEY, false);
+			} else {
+				JSONObject provider_json = new JSONObject(provider_dot_json_string);
+				ConfigHelper.saveSharedPref(EIP.ALLOWED_ANON, provider_json.getJSONObject(Provider.SERVICE).getBoolean(EIP.ALLOWED_ANON));
+
+				//ProviderListContent.addItem(new ProviderItem(provider_name, provider_json_url, provider_json, custom, danger_on));
+				result.putBoolean(RESULT_KEY, true);
+				result.putString(Provider.KEY, provider_json.toString());
+				result.putBoolean(ProviderItem.DANGER_ON, danger_on);
+			}
+		} catch (JSONException e) {
+			result.putBoolean(RESULT_KEY, false);
+		}
+		
+		return result;
+	}
+
+	/**
+	 * Downloads a custom provider provider.json file
+	 * @param task containing a boolean meaning if the user completely trusts this provider, and the provider main url entered in the new custom provider dialog.
+	 * @return true if provider.json file was successfully parsed as a JSON object.
+	 */
+	private Bundle downloadNewProviderDotJSON(Bundle task) {
+		Bundle result = new Bundle();
+		boolean custom = true;
+		boolean danger_on = task.getBoolean(ProviderItem.DANGER_ON);
+		
+		String provider_main_url = (String) task.get(Provider.MAIN_URL);
+		String provider_name = provider_main_url.replaceFirst("http[s]?://", "").replaceFirst("\\/", "_");
+		String provider_json_url = guessProviderDotJsonURL(provider_main_url);
+		
+		String provider_json_string = downloadWithCommercialCA(provider_json_url, danger_on);
+		try {
+			if(provider_json_string.isEmpty()) {
+				result.putBoolean(RESULT_KEY, false);
+			} else {
+				JSONObject provider_json = new JSONObject(provider_json_string);
+
+				ConfigHelper.saveSharedPref(Provider.KEY, provider_json);
+				ConfigHelper.saveSharedPref(ProviderItem.DANGER_ON, danger_on);
+				ConfigHelper.saveSharedPref(EIP.ALLOWED_ANON, provider_json.getJSONObject(Provider.SERVICE).getBoolean(EIP.ALLOWED_ANON));
+				ProviderItem added_provider = new ProviderItem(provider_name, provider_json_url, provider_json, custom, danger_on);
+				ProviderListContent.addItem(added_provider);
+
+				result.putString(Provider.NAME, added_provider.getName());
+				result.putBoolean(RESULT_KEY, true);
+				result.putString(Provider.KEY, provider_json.toString());
+				result.putBoolean(ProviderItem.DANGER_ON, danger_on);
+			}
+		} catch (JSONException e) {
+			result.putBoolean(RESULT_KEY, false);
+		}
+		
+		return result;
+	}
+	
+	/**
+	 * Tries to download the contents of the provided url using commercially validated CA certificate from chosen provider.
+	 * 
+	 * If danger_on flag is true, SSL exceptions will be managed by futher methods that will try to use some bypass methods.
+	 * @param string_url
+	 * @param danger_on if the user completely trusts this provider
+	 * @return
+	 */
+	private String downloadWithCommercialCA(String string_url, boolean danger_on) {
+		
+		String json_file_content = "";
+		
+		URL provider_url = null;
+		int seconds_of_timeout = 1;
+		try {
+			provider_url = new URL(string_url);
+			URLConnection url_connection = provider_url.openConnection();
+			url_connection.setConnectTimeout(seconds_of_timeout*1000);
+			json_file_content = new Scanner(url_connection.getInputStream()).useDelimiter("\\A").next();
+		} catch (MalformedURLException e) {
+			displayToast(R.string.malformed_url);
+		} catch(SocketTimeoutException e) {
+			displayToast(R.string.server_is_down_message);
+		} catch (FileNotFoundException e) {
+			e.printStackTrace();
+			displayToast(R.string.server_is_down_message);
+		} catch (IOException e) {
+			if(provider_url != null) {
+				json_file_content = downloadWithProviderCA(provider_url, danger_on);
+			} else {
+				displayToast(R.string.certificate_error);
+			}
+		} catch (Exception e) {
+			if(provider_url != null && danger_on) {
+				json_file_content = downloadWithProviderCA(provider_url, danger_on);
+			}
+		}
+
+		return json_file_content;
+	}
+
+	/**
+	 * Tries to download the contents of the provided url using not commercially validated CA certificate from chosen provider. 
+	 * @param url
+	 * @param danger_on true to download CA certificate in case it has not been downloaded.
+	 * @return an empty string if it fails, the url content if not. 
+	 */
+	private String downloadWithProviderCA(URL url, boolean danger_on) {
+		String json_file_content = "";
+
+		try {
+			// Tell the URLConnection to use a SocketFactory from our SSLContext
+			HttpsURLConnection urlConnection =
+					(HttpsURLConnection)url.openConnection();
+			urlConnection.setSSLSocketFactory(getProviderSSLSocketFactory());
+			json_file_content = new Scanner(urlConnection.getInputStream()).useDelimiter("\\A").next();
+		} catch (CertificateException e) {
+			// TODO Auto-generated catch block
+			e.printStackTrace();
+		} catch (UnknownHostException e) {
+			displayToast(R.string.server_is_down_message);
+		} catch (FileNotFoundException e) {
+			e.printStackTrace();
+			displayToast(R.string.server_is_down_message);
+		} catch (IOException e) {
+			// The downloaded certificate doesn't validate our https connection.
+			if(danger_on) {
+				json_file_content = downloadWithoutCA(url);
+			} else {
+				displayToast(R.string.certificate_error);
+			}
+		} catch (KeyStoreException e) {
+			// TODO Auto-generated catch block
+			e.printStackTrace();
+		} catch (NoSuchAlgorithmException e) {
+			// TODO Auto-generated catch block
+			e.printStackTrace();
+		} catch (KeyManagementException e) {
+			// TODO Auto-generated catch block
+			e.printStackTrace();
+		}
+		return json_file_content;
+	}
+	
+	private javax.net.ssl.SSLSocketFactory getProviderSSLSocketFactory() throws KeyStoreException, NoSuchAlgorithmException, CertificateException, IOException, KeyManagementException {
+		String provider_cert_string = ConfigHelper.getStringFromSharedPref(Provider.CA_CERT);
+
+		java.security.cert.Certificate provider_certificate = ConfigHelper.parseX509CertificateFromString(provider_cert_string);
+
+		// Create a KeyStore containing our trusted CAs
+		String keyStoreType = KeyStore.getDefaultType();
+		KeyStore keyStore = KeyStore.getInstance(keyStoreType);
+		keyStore.load(null, null);
+		keyStore.setCertificateEntry("provider_ca_certificate", provider_certificate);
+
+		// Create a TrustManager that trusts the CAs in our KeyStore
+		String tmfAlgorithm = TrustManagerFactory.getDefaultAlgorithm();
+		TrustManagerFactory tmf = TrustManagerFactory.getInstance(tmfAlgorithm);
+		tmf.init(keyStore);
+
+		// Create an SSLContext that uses our TrustManager
+		SSLContext context = SSLContext.getInstance("TLS");
+		context.init(null, tmf.getTrustManagers(), null);
+
+		return context.getSocketFactory();
+	}
+	
+	/**
+	 * Downloads the string that's in the url with any certificate.
+	 */
+	private String downloadWithoutCA(URL url) {
+		String string = "";
+		try {
+
+			HostnameVerifier hostnameVerifier = new HostnameVerifier() {
+				@Override
+				public boolean verify(String hostname, SSLSession session) {
+					return true;
+				}
+			};
+			
+			class DefaultTrustManager implements X509TrustManager {
+
+				@Override
+					public void checkClientTrusted(X509Certificate[] arg0, String arg1) throws CertificateException {}
+
+				@Override
+					public void checkServerTrusted(X509Certificate[] arg0, String arg1) throws CertificateException {}
+
+				@Override
+					public X509Certificate[] getAcceptedIssuers() {
+						return null;
+					}
+			}
+
+			SSLContext context = SSLContext.getInstance("TLS");
+			context.init(new KeyManager[0], new TrustManager[] {new DefaultTrustManager()}, new SecureRandom());
+
+			HttpsURLConnection urlConnection = (HttpsURLConnection)url.openConnection();
+			urlConnection.setSSLSocketFactory(context.getSocketFactory());
+			urlConnection.setHostnameVerifier(hostnameVerifier);
+			string = new Scanner(urlConnection.getInputStream()).useDelimiter("\\A").next();
+			System.out.println("String ignoring certificate = " + string);
+		} catch (FileNotFoundException e) {
+			e.printStackTrace();
+			displayToast(R.string.server_is_down_message);
+		} catch (IOException e) {
+			// The downloaded certificate doesn't validate our https connection.
+			e.printStackTrace();
+			displayToast(R.string.certificate_error);
+		} catch (NoSuchAlgorithmException e) {
+			// TODO Auto-generated catch block
+			e.printStackTrace();
+		} catch (KeyManagementException e) {
+			// TODO Auto-generated catch block
+			e.printStackTrace();
+		}
+		return string;
+	}
+
+	/**
+	 * Tries to guess the provider.json url given the main provider url.
+	 * @param provider_main_url
+	 * @return the guessed provider.json url
+	 */
+	private String guessProviderDotJsonURL(String provider_main_url) {
+		return provider_main_url + "/provider.json";
+	}
+	
+	/**
+	 * Logs out from the api url retrieved from the task.
+	 * @param task containing api url from which the user will log out
+	 * @return true if there were no exceptions
+	 */
+	private boolean logOut(Bundle task) {
+		try {
+			String delete_url = task.getString(Provider.API_URL) + "/logout";
+
+			HttpsURLConnection urlConnection = (HttpsURLConnection)new URL(delete_url).openConnection();
+			urlConnection.setRequestMethod("DELETE");
+			urlConnection.setSSLSocketFactory(getProviderSSLSocketFactory());
+
+			int responseCode = urlConnection.getResponseCode();
+			Log.d("logout", Integer.toString(responseCode));
+		} catch (ClientProtocolException e) {
+			// TODO Auto-generated catch block
+			e.printStackTrace();
+			return false;
+		} catch (IndexOutOfBoundsException e) {
+			// TODO Auto-generated catch block
+			e.printStackTrace();
+			return false;
+		} catch (IOException e) {
+			// TODO Auto-generated catch block
+			e.printStackTrace();
+			return false;
+		} catch (KeyManagementException e) {
+			// TODO Auto-generated catch block
+			e.printStackTrace();
+		} 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();
+		}
+		return true;
+	}
+
+	/**
+	 * Downloads a new OpenVPN certificate, attaching authenticated cookie for authenticated certificate.
+	 * 
+	 * @param task containing the type of the certificate to be downloaded
+	 * @return true if certificate was downloaded correctly, false if provider.json or danger_on flag are 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 getNewCert(Bundle task) {
+
+		try {
+			String type_of_certificate = task.getString(ConfigurationWizard.TYPE_OF_CERTIFICATE);
+			JSONObject provider_json = ConfigHelper.getJsonFromSharedPref(Provider.KEY);
+			URL provider_main_url = new URL(provider_json.getString(Provider.API_URL));
+			String new_cert_string_url = provider_main_url.toString() + "/" + provider_json.getString(Provider.API_VERSION) + "/" + EIP.CERTIFICATE;
+
+			boolean danger_on = ConfigHelper.getBoolFromSharedPref(ProviderItem.DANGER_ON);
+			String cert_string = downloadWithCommercialCA(new_cert_string_url, danger_on);
+			if(!cert_string.isEmpty()) {
+				// 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];
+					}
+				}
+				try {
+					RSAPrivateKey keyCert = ConfigHelper.parseRsaKeyFromString(keyString);
+					keyString = Base64.encodeToString( keyCert.getEncoded(), Base64.DEFAULT );
+					ConfigHelper.saveSharedPref(EIP.PRIVATE_KEY, "-----BEGIN RSA PRIVATE KEY-----\n"+keyString+"-----END RSA PRIVATE KEY-----");
+					
+					X509Certificate certCert = ConfigHelper.parseX509CertificateFromString(certificateString);
+					certificateString = Base64.encodeToString( certCert.getEncoded(), Base64.DEFAULT);
+					ConfigHelper.saveSharedPref(EIP.CERTIFICATE, "-----BEGIN CERTIFICATE-----\n"+certificateString+"-----END CERTIFICATE-----");
+					
+					return true;
+				} catch (CertificateException e) {
+					// TODO Auto-generated catch block
+					e.printStackTrace();
+					return false;
+				}
+			} else {
+				return false;
+			}
+		} catch (IOException e) {
+			// TODO Auto-generated catch block
+			e.printStackTrace();
+			return false;
+		} catch (JSONException e) {
+			// TODO Auto-generated catch block
+			e.printStackTrace();
+			return false;
+		} /*catch (URISyntaxException e) {
+			// TODO Auto-generated catch block
+			e.printStackTrace();
+			return false;
+		}*/
+	}
+}