squashed commit for Pluggable Transports

* implement handling of different provider API version (v1 and v2)
* detect provider's obfs support
* shapeshifter-dispatcher installation
* necessary changes to control shapeshifter-dispatcher from Bitmask
* route openvpn traffic over shapeshifter-dispatcher

9 files changed, 432 insertions, 48 deletions

diff --git a/app/src/main/java/de/blinkt/openvpn/VpnProfile.java b/app/src/main/java/de/blinkt/openvpn/VpnProfile.java
index 7b9003aa..9f18b8ed 100644
--- a/app/src/main/java/de/blinkt/openvpn/VpnProfile.java
+++ b/app/src/main/java/de/blinkt/openvpn/VpnProfile.java
@@ -5,6 +5,11 @@
 
 package de.blinkt.openvpn;
 
+import de.blinkt.openvpn.core.connection.Connection;
+import de.blinkt.openvpn.core.connection.OpenvpnConnection;
+import se.leap.bitmaskclient.R;
+import se.leap.bitmaskclient.BuildConfig;
+
 import android.annotation.SuppressLint;
 import android.content.Context;
 import android.content.Intent;
@@ -189,7 +194,7 @@ public class VpnProfile implements Serializable, Cloneable {
         mProfileVersion = CURRENT_PROFILE_VERSION;
 
         mConnections = new Connection[1];
-        mConnections[0] = new Connection();
+        mConnections[0] = new OpenvpnConnection();
         mLastUsed = System.currentTimeMillis();
     }
 
@@ -314,8 +319,8 @@ public class VpnProfile implements Serializable, Cloneable {
         }
         if (mProfileVersion < 7) {
             for (Connection c : mConnections)
-                if (c.mProxyType == null)
-                    c.mProxyType = Connection.ProxyType.NONE;
+                if (c.getProxyType() == null)
+                    c.setProxyType(Connection.ProxyType.NONE);
         }
 
         mProfileVersion = CURRENT_PROFILE_VERSION;
@@ -324,12 +329,12 @@ public class VpnProfile implements Serializable, Cloneable {
 
     private void moveOptionsToConnection() {
         mConnections = new Connection[1];
-        Connection conn = new Connection();
+        Connection conn = new OpenvpnConnection();
 
-        conn.mServerName = mServerName;
-        conn.mServerPort = mServerPort;
-        conn.mUseUdp = mUseUdp;
-        conn.mCustomConfiguration = "";
+        conn.setServerName(mServerName);
+        conn.setServerPort(mServerPort);
+        conn.setUseUdp(mUseUdp);
+        conn.setCustomConfiguration("");
 
         mConnections[0] = conn;
 
@@ -425,7 +430,7 @@ public class VpnProfile implements Serializable, Cloneable {
 
             if (canUsePlainRemotes) {
                 for (Connection conn : mConnections) {
-                    if (conn.mEnabled) {
+                    if (conn.isEnabled()) {
                         cfg.append(conn.getConnectionBlock(configForOvpn3));
                     }
                 }
@@ -586,7 +591,7 @@ public class VpnProfile implements Serializable, Cloneable {
         if (mAuthenticationType != TYPE_STATICKEYS) {
             if (mCheckRemoteCN) {
                 if (mRemoteCN == null || mRemoteCN.equals(""))
-                    cfg.append("verify-x509-name ").append(openVpnEscape(mConnections[0].mServerName)).append(" name\n");
+                    cfg.append("verify-x509-name ").append(openVpnEscape(mConnections[0].getServerName())).append(" name\n");
                 else
                     switch (mX509AuthType) {
 
@@ -660,7 +665,7 @@ public class VpnProfile implements Serializable, Cloneable {
         if (!canUsePlainRemotes) {
             cfg.append("# Connection Options are at the end to allow global options (and global custom options) to influence connection blocks\n");
             for (Connection conn : mConnections) {
-                if (conn.mEnabled) {
+                if (conn.isEnabled()) {
                     cfg.append("<connection>\n");
                     cfg.append(conn.getConnectionBlock(configForOvpn3));
                     cfg.append("</connection>\n");
@@ -985,7 +990,7 @@ public class VpnProfile implements Serializable, Cloneable {
 
         boolean noRemoteEnabled = true;
         for (Connection c : mConnections) {
-            if (c.mEnabled)
+            if (c.isEnabled())
                 noRemoteEnabled = false;
 
         }
@@ -1000,12 +1005,12 @@ public class VpnProfile implements Serializable, Cloneable {
                 return R.string.openvpn3_pkcs12;
             }
             for (Connection conn : mConnections) {
-                if (conn.mProxyType == Connection.ProxyType.ORBOT || conn.mProxyType == Connection.ProxyType.SOCKS5)
+                if (conn.getProxyType() == Connection.ProxyType.ORBOT || conn.getProxyType() == Connection.ProxyType.SOCKS5)
                     return R.string.openvpn3_socksproxy;
             }
         }
         for (Connection c : mConnections) {
-            if (c.mProxyType == Connection.ProxyType.ORBOT) {
+            if (c.getProxyType() == Connection.ProxyType.ORBOT) {
                 if (usesExtraProxyOptions())
                     return R.string.error_orbot_and_proxy_options;
                 if (!OrbotHelper.checkTorReceier(context))
diff --git a/app/src/main/java/de/blinkt/openvpn/core/ConfigParser.java b/app/src/main/java/de/blinkt/openvpn/core/ConfigParser.java
index 0148bfb7..0e9b1bc4 100644
--- a/app/src/main/java/de/blinkt/openvpn/core/ConfigParser.java
+++ b/app/src/main/java/de/blinkt/openvpn/core/ConfigParser.java
@@ -6,16 +6,24 @@
 package de.blinkt.openvpn.core;
 
 import android.os.Build;
-import android.support.v4.util.Pair;
 import android.text.TextUtils;
+import android.support.v4.util.Pair;
 
 import java.io.BufferedReader;
 import java.io.IOException;
 import java.io.Reader;
 import java.io.StringReader;
-import java.util.*;
+import java.util.Arrays;
+import java.util.Collections;
+import java.util.HashMap;
+import java.util.HashSet;
+import java.util.Locale;
+import java.util.Map;
+import java.util.Vector;
 
 import de.blinkt.openvpn.VpnProfile;
+import de.blinkt.openvpn.core.connection.Connection;
+import de.blinkt.openvpn.core.connection.OpenvpnConnection;
 
 //! Openvpn Config FIle Parser, probably not 100% accurate but close enough
 
@@ -142,9 +150,9 @@ public class ConfigParser {
         String data = VpnProfile.getEmbeddedContent(inlinedata);
         String[] parts = data.split("\n");
         if (parts.length >= 2) {
-            c.mProxyAuthUser = parts[0];
-            c.mProxyAuthPassword = parts[1];
-            c.mUseProxyAuth = true;
+            c.setProxyAuthUser(parts[0]);
+            c.setProxyAuthPassword(parts[1]);
+            c.setUseProxyAuth(true);
         }
     }
 
@@ -605,7 +613,7 @@ public class ConfigParser {
         }
 
 
-        if (getOption("nobind", 0, 0) != null)
+        if (getOption("nobind", 0, 1) != null)
             np.mNobind = true;
 
         if (getOption("persist-tun", 0, 0) != null)
@@ -713,8 +721,8 @@ public class ConfigParser {
                 throw new ConfigParseError(String.format("Unknown protocol %s in proto-force", protoToDisable));
 
             for (Connection conn : np.mConnections)
-                if (conn.mUseUdp == disableUDP)
-                    conn.mEnabled = false;
+                if (conn.isUseUdp() == disableUDP)
+                    conn.setEnabled(false);
         }
 
         // Parse OpenVPN Access Server extra
@@ -763,27 +771,27 @@ public class ConfigParser {
                 return null;
             }
         else
-            conn = new Connection();
+            conn = new OpenvpnConnection();
 
         Vector<String> port = getOption("port", 1, 1);
         if (port != null) {
-            conn.mServerPort = port.get(1);
+            conn.setServerPort(port.get(1));
         }
 
         Vector<String> rport = getOption("rport", 1, 1);
         if (rport != null) {
-            conn.mServerPort = rport.get(1);
+            conn.setServerPort(rport.get(1));
         }
 
         Vector<String> proto = getOption("proto", 1, 1);
         if (proto != null) {
-            conn.mUseUdp = isUdpProto(proto.get(1));
+            conn.setUseUdp(isUdpProto(proto.get(1)));
         }
 
         Vector<String> connectTimeout = getOption("connect-timeout", 1, 1);
         if (connectTimeout != null) {
             try {
-                conn.mConnectTimeout = Integer.parseInt(connectTimeout.get(1));
+                conn.setConnectTimeout(Integer.parseInt(connectTimeout.get(1)));
             } catch (NumberFormatException nfe) {
                 throw new ConfigParseError(String.format("Argument to connect-timeout (%s) must to be an integer: %s",
                         connectTimeout.get(1), nfe.getLocalizedMessage()));
@@ -797,16 +805,16 @@ public class ConfigParser {
 
         if (proxy != null) {
             if (proxy.get(0).equals("socks-proxy")) {
-                conn.mProxyType = Connection.ProxyType.SOCKS5;
+                conn.setProxyType(Connection.ProxyType.SOCKS5);
                 // socks defaults to 1080, http always sets port
-                conn.mProxyPort = "1080";
+                conn.setProxyPort("1080");
             } else {
-                conn.mProxyType = Connection.ProxyType.HTTP;
+                conn.setProxyType(Connection.ProxyType.HTTP);
             }
 
-            conn.mProxyName = proxy.get(1);
+            conn.setProxyName(proxy.get(1));
             if (proxy.size() >= 3)
-                conn.mProxyPort = proxy.get(2);
+                conn.setProxyPort(proxy.get(2));
         }
 
         Vector<String> httpproxyauthhttp = getOption("http-proxy-user-pass", 1, 1);
@@ -823,15 +831,15 @@ public class ConfigParser {
         // Assume that we need custom options if connectionDefault are set or in the connection specific set
         for (Map.Entry<String, Vector<Vector<String>>> option : options.entrySet()) {
             if (connDefault != null || connectionOptionsSet.contains(option.getKey())) {
-                conn.mCustomConfiguration += getOptionStrings(option.getValue());
+                conn.setCustomConfiguration(conn.getCustomConfiguration() + getOptionStrings(option.getValue()));
                 optionsToRemove.add(option.getKey());
             }
         }
         for (String o: optionsToRemove)
             options.remove(o);
 
-        if (!(conn.mCustomConfiguration == null || "".equals(conn.mCustomConfiguration.trim())))
-            conn.mUseCustomConfig = true;
+        if (!(conn.getCustomConfiguration() == null || "".equals(conn.getCustomConfiguration().trim())))
+            conn.setUseCustomConfig(true);
 
         // Make remotes empty to simplify code
         if (remotes == null)
@@ -849,11 +857,11 @@ public class ConfigParser {
             }
             switch (remote.size()) {
                 case 4:
-                    connections[i].mUseUdp = isUdpProto(remote.get(3));
+                    connections[i].setUseUdp(isUdpProto(remote.get(3)));
                 case 3:
-                    connections[i].mServerPort = remote.get(2);
+                    connections[i].setServerPort(remote.get(2));
                 case 2:
-                    connections[i].mServerName = remote.get(1);
+                    connections[i].setServerName(remote.get(1));
             }
             i++;
         }
diff --git a/app/src/main/java/de/blinkt/openvpn/core/ConnectionInterface.java b/app/src/main/java/de/blinkt/openvpn/core/ConnectionInterface.java
new file mode 100644
index 00000000..70b4b4ec
--- /dev/null
+++ b/app/src/main/java/de/blinkt/openvpn/core/ConnectionInterface.java
@@ -0,0 +1,15 @@
+package de.blinkt.openvpn.core;
+
+import java.io.Serializable;
+
+/**
+ * Created by cyberta on 11.03.19.
+ */
+
+public interface ConnectionInterface {
+
+    String getConnectionBlock(boolean isOpenVPN3);
+    boolean usesExtraProxyOptions();
+    boolean isOnlyRemote();
+     int getTimeout();
+}
diff --git a/app/src/main/java/de/blinkt/openvpn/core/NativeUtils.java b/app/src/main/java/de/blinkt/openvpn/core/NativeUtils.java
index 6b633c34..a66b7b51 100644
--- a/app/src/main/java/de/blinkt/openvpn/core/NativeUtils.java
+++ b/app/src/main/java/de/blinkt/openvpn/core/NativeUtils.java
@@ -20,6 +20,8 @@ public class NativeUtils {
     {
         if (isRoboUnitTest())
             return "ROBO";
+        else if (isUnitTest())
+            return "JUNIT";
         else
             return getJNIAPI();
     }
@@ -34,7 +36,7 @@ public class NativeUtils {
     public static native double[] getOpenSSLSpeed(String algorithm, int testnum);
 
     static {
-        if (!isRoboUnitTest()) {
+        if (!isRoboUnitTest() && !isUnitTest()) {
             System.loadLibrary("opvpnutil");
             if (Build.VERSION.SDK_INT == Build.VERSION_CODES.JELLY_BEAN)
                 System.loadLibrary("jbcrypto");
@@ -44,4 +46,13 @@ public class NativeUtils {
     public static boolean isRoboUnitTest() {
         return "robolectric".equals(Build.FINGERPRINT);
     }
+
+    public static boolean isUnitTest() {
+        try {
+            Class.forName("se.leap.bitmaskclient.testutils.MockHelper");
+            return true;
+        } catch (ClassNotFoundException e) {
+            return false;
+        }
+    }
 }
diff --git a/app/src/main/java/de/blinkt/openvpn/core/OpenVPNService.java b/app/src/main/java/de/blinkt/openvpn/core/OpenVPNService.java
index 82c4e1df..55a92cb0 100644
--- a/app/src/main/java/de/blinkt/openvpn/core/OpenVPNService.java
+++ b/app/src/main/java/de/blinkt/openvpn/core/OpenVPNService.java
@@ -42,9 +42,13 @@ import java.util.Vector;
 import de.blinkt.openvpn.VpnProfile;
 import de.blinkt.openvpn.core.VpnStatus.ByteCountListener;
 import de.blinkt.openvpn.core.VpnStatus.StateListener;
+import de.blinkt.openvpn.core.connection.Connection;
 import se.leap.bitmaskclient.R;
 import se.leap.bitmaskclient.VpnNotificationManager;
+import se.leap.bitmaskclient.pluggableTransports.Dispatcher;
+import de.blinkt.openvpn.core.connection.Obfs4Connection;
 
+import static de.blinkt.openvpn.core.connection.Connection.TransportType.OBFS4;
 import static de.blinkt.openvpn.core.ConnectionStatus.LEVEL_CONNECTED;
 import static de.blinkt.openvpn.core.ConnectionStatus.LEVEL_WAITING_FOR_USER_INPUT;
 import static de.blinkt.openvpn.core.NetworkSpace.IpAddress;
@@ -52,6 +56,7 @@ import static se.leap.bitmaskclient.Constants.PROVIDER_PROFILE;
 
 
 public class OpenVPNService extends VpnService implements StateListener, Callback, ByteCountListener, IOpenVPNServiceInternal, VpnNotificationManager.VpnServiceCallback {
+    public static final String TAG = OpenVPNService.class.getSimpleName();
     public static final String START_SERVICE = "de.blinkt.openvpn.START_SERVICE";
     public static final String START_SERVICE_STICKY = "de.blinkt.openvpn.START_SERVICE_STICKY";
     public static final String ALWAYS_SHOW_NOTIFICATION = "de.blinkt.openvpn.NOTIFICATION_ALWAYS_VISIBLE";
@@ -85,6 +90,7 @@ public class OpenVPNService extends VpnService implements StateListener, Callbac
     private Toast mlastToast;
     private Runnable mOpenVPNThread;
     private VpnNotificationManager notificationManager;
+    private Dispatcher dispatcher;
 
     private static final int PRIORITY_MIN = -2;
     private static final int PRIORITY_DEFAULT = 0;
@@ -242,6 +248,9 @@ public class OpenVPNService extends VpnService implements StateListener, Callbac
         if(isVpnRunning()) {
             if (getManagement() != null && getManagement().stopVPN(replaceConnection)) {
                 if (!replaceConnection) {
+                    if (dispatcher.isRunning()) {
+                        dispatcher.stop();
+                    }
                     VpnStatus.updateStateString("NOPROCESS", "VPN STOPPED", R.string.state_noprocess, ConnectionStatus.LEVEL_NOTCONNECTED);
                 }
                 return true;
@@ -249,6 +258,9 @@ public class OpenVPNService extends VpnService implements StateListener, Callbac
             return false;
         } else {
             if (!replaceConnection) {
+                if (dispatcher.isRunning()) {
+                    dispatcher.stop();
+                }
                 VpnStatus.updateStateString("NOPROCESS", "VPN STOPPED", R.string.state_noprocess, ConnectionStatus.LEVEL_NOTCONNECTED);
                 return true;
             }
@@ -366,6 +378,36 @@ public class OpenVPNService extends VpnService implements StateListener, Callbac
         /**
          * see change above (l. 292 ff)
          */
+        //TODO: investigate how connections[n] with n>0 get called during vpn setup (on connection refused?)
+        // Do we need to check if there's any obfs4 connection in mProfile.mConnections and start
+        // the dispatcher here? Can we start the dispatcher at a later point of execution, e.g. when
+        // connections[n], n>0 gets choosen?
+
+        VpnStatus.logInfo("Setting up dispatcher.");
+        Connection connection = mProfile.mConnections[0];
+
+        if (connection.getTransportType() == OBFS4) {
+            Obfs4Connection obfs4Connection = (Obfs4Connection) connection;
+            dispatcher = new Dispatcher(this,
+                    obfs4Connection.getmObfs4RemoteProxyName(),
+                    obfs4Connection.getmObfs4RemoteProxyPort(),
+                    obfs4Connection.getmObfs4Certificate(),
+                    obfs4Connection.getmObfs4IatMode());
+            dispatcher.initSync();
+
+            if (dispatcher.getPort() != null && dispatcher.getPort().length() > 0) {
+                connection.setServerPort(dispatcher.getPort());
+                Log.d(TAG, "Dispatcher running. Profile server name and port: " +
+                        connection.getServerName() + ":" + connection.getServerPort());
+                VpnStatus.logInfo("Dispatcher running. Profile server name and port: " +
+                        connection.getServerName() + ":" + connection.getServerPort());
+            } else {
+                Log.e(TAG, "Cannot initialize dispatcher for obfs4 connection. Shutting down.");
+                VpnStatus.logError("Cannot initialize dispatcher for obfs4 connection. Shutting down.");
+            }
+        }
+
+
         VpnStatus.logInfo(R.string.building_configration);
         VpnStatus.updateStateString("VPN_GENERATE_CONFIG", "", R.string.building_configration, ConnectionStatus.LEVEL_START);
 
@@ -743,7 +785,7 @@ public class OpenVPNService extends VpnService implements StateListener, Callbac
         boolean profileUsesOrBot = false;
 
         for (Connection c : mProfile.mConnections) {
-            if (c.mProxyType == Connection.ProxyType.ORBOT)
+            if (c.getProxyType() == Connection.ProxyType.ORBOT)
                 profileUsesOrBot = true;
         }
 
diff --git a/app/src/main/java/de/blinkt/openvpn/core/OpenVpnManagementThread.java b/app/src/main/java/de/blinkt/openvpn/core/OpenVpnManagementThread.java
index 4f7a5bda..91cc66bc 100644
--- a/app/src/main/java/de/blinkt/openvpn/core/OpenVpnManagementThread.java
+++ b/app/src/main/java/de/blinkt/openvpn/core/OpenVpnManagementThread.java
@@ -15,9 +15,10 @@ import android.os.Handler;
 import android.os.ParcelFileDescriptor;
 import android.support.annotation.NonNull;
 import android.support.annotation.RequiresApi;
-import android.system.ErrnoException;
 import android.system.Os;
 import android.util.Log;
+
+import de.blinkt.openvpn.core.connection.Connection;
 import se.leap.bitmaskclient.R;
 import de.blinkt.openvpn.VpnProfile;
 
@@ -452,10 +453,10 @@ public class OpenVpnManagementThread implements Runnable, OpenVPNManagement {
 
         if (mProfile.mConnections.length > connectionEntryNumber) {
             Connection connection = mProfile.mConnections[connectionEntryNumber];
-            proxyType = connection.mProxyType;
-            proxyname = connection.mProxyName;
-            proxyport = connection.mProxyPort;
-            proxyUseAuth = connection.mUseProxyAuth;
+            proxyType = connection.getProxyType();
+            proxyname = connection.getProxyName();
+            proxyport = connection.getProxyPort();
+            proxyUseAuth = connection.isUseProxyAuth();
 
             // Use transient variable to remember http user/password
             mCurrentProxyConnection = connection;
@@ -696,8 +697,8 @@ public class OpenVpnManagementThread implements Runnable, OpenVPNManagement {
 
         } else if (needed.equals("HTTP Proxy")) {
             if( mCurrentProxyConnection != null) {
-                pw = mCurrentProxyConnection.mProxyAuthPassword;
-                username = mCurrentProxyConnection.mProxyAuthUser;
+                pw = mCurrentProxyConnection.getProxyAuthPassword();
+                username = mCurrentProxyConnection.getProxyAuthUser();
             }
         }
         if (pw != null) {
@@ -782,7 +783,6 @@ public class OpenVpnManagementThread implements Runnable, OpenVPNManagement {
         boolean stopSucceed = stopOpenVPN();
         if (stopSucceed) {
             mShuttingDown = true;
-
         }
         return stopSucceed;
     }
diff --git a/app/src/main/java/de/blinkt/openvpn/core/connection/Connection.java b/app/src/main/java/de/blinkt/openvpn/core/connection/Connection.java
new file mode 100644
index 00000000..f333a13e
--- /dev/null
+++ b/app/src/main/java/de/blinkt/openvpn/core/connection/Connection.java
@@ -0,0 +1,207 @@
+/*
+ * Copyright (c) 2012-2016 Arne Schwabe
+ * Distributed under the GNU GPL v2 with additional terms. For full terms see the file doc/LICENSE.txt
+ */
+
+package de.blinkt.openvpn.core.connection;
+
+import android.text.TextUtils;
+
+import java.io.Serializable;
+import java.util.Locale;
+
+public abstract class Connection implements Serializable, Cloneable {
+    private String mServerName = "openvpn.example.com";
+    private String mServerPort = "1194";
+    private boolean mUseUdp = true;
+    private String mCustomConfiguration = "";
+    private boolean mUseCustomConfig = false;
+    private boolean mEnabled = true;
+    private int mConnectTimeout = 0;
+    private static final int CONNECTION_DEFAULT_TIMEOUT = 120;
+    private ProxyType mProxyType = ProxyType.NONE;
+    private String mProxyName = "proxy.example.com";
+    private String mProxyPort = "8080";
+
+    private boolean mUseProxyAuth;
+    private String mProxyAuthUser = null;
+    private String mProxyAuthPassword = null;
+
+    public enum ProxyType {
+        NONE,
+        HTTP,
+        SOCKS5,
+        ORBOT
+    }
+
+    public enum TransportType {
+        OBFS4,
+        OPENVPN
+    }
+
+    private static final long serialVersionUID = 92031902903829089L;
+
+
+    public String getConnectionBlock(boolean isOpenVPN3) {
+        String cfg = "";
+
+        // Server Address
+        cfg += "remote ";
+        cfg += mServerName;
+        cfg += " ";
+        cfg += mServerPort;
+        if (mUseUdp)
+            cfg += " udp\n";
+        else
+            cfg += " tcp-client\n";
+
+        if (mConnectTimeout != 0)
+            cfg += String.format(Locale.US, " connect-timeout  %d\n", mConnectTimeout);
+
+        // OpenVPN 2.x manages proxy connection via management interface
+        if ((isOpenVPN3 || usesExtraProxyOptions()) && mProxyType == ProxyType.HTTP)
+        {
+            cfg+=String.format(Locale.US,"http-proxy %s %s\n", mProxyName, mProxyPort);
+            if (mUseProxyAuth)
+                cfg+=String.format(Locale.US, "<http-proxy-user-pass>\n%s\n%s\n</http-proxy-user-pass>\n", mProxyAuthUser, mProxyAuthPassword);
+        }
+        if (usesExtraProxyOptions() && mProxyType == ProxyType.SOCKS5) {
+            cfg+=String.format(Locale.US,"socks-proxy %s %s\n", mProxyName, mProxyPort);
+        }
+
+        if (!TextUtils.isEmpty(mCustomConfiguration) && mUseCustomConfig) {
+            cfg += mCustomConfiguration;
+            cfg += "\n";
+        }
+
+
+        return cfg;
+    }
+
+    public boolean usesExtraProxyOptions() {
+        return (mUseCustomConfig && mCustomConfiguration.contains("http-proxy-option "));
+    }
+
+
+    @Override
+    public Connection clone() throws CloneNotSupportedException {
+        return (Connection) super.clone();
+    }
+
+    public boolean isOnlyRemote() {
+        return TextUtils.isEmpty(mCustomConfiguration) || !mUseCustomConfig;
+    }
+
+    public int getTimeout() {
+        if (mConnectTimeout <= 0)
+            return CONNECTION_DEFAULT_TIMEOUT;
+        else
+            return mConnectTimeout;
+    }
+
+    public String getServerName() {
+        return mServerName;
+    }
+
+    public void setServerName(String mServerName) {
+        this.mServerName = mServerName;
+    }
+
+    public String getServerPort() {
+        return mServerPort;
+    }
+
+    public void setServerPort(String serverPort) {
+        this.mServerPort = serverPort;
+    }
+
+    public boolean isUseUdp() {
+        return mUseUdp;
+    }
+
+    public void setUseUdp(boolean useUdp) {
+        this.mUseUdp = useUdp;
+    }
+
+    public String getCustomConfiguration() {
+        return mCustomConfiguration;
+    }
+
+    public void setCustomConfiguration(String customConfiguration) {
+        this.mCustomConfiguration = customConfiguration;
+    }
+
+    public boolean isUseCustomConfig() {
+        return mUseCustomConfig;
+    }
+
+    public void setUseCustomConfig(boolean useCustomConfig) {
+        this.mUseCustomConfig = useCustomConfig;
+    }
+
+    public boolean isEnabled() {
+        return mEnabled;
+    }
+
+    public void setEnabled(boolean enabled) {
+        this.mEnabled = enabled;
+    }
+
+    public int getConnectTimeout() {
+        return mConnectTimeout;
+    }
+
+    public void setConnectTimeout(int connectTimeout) {
+        this.mConnectTimeout = connectTimeout;
+    }
+
+    public ProxyType getProxyType() {
+        return mProxyType;
+    }
+
+    public void setProxyType(ProxyType proxyType) {
+        this.mProxyType = proxyType;
+    }
+
+    public String getProxyName() {
+        return mProxyName;
+    }
+
+    public void setProxyName(String proxyName) {
+        this.mProxyName = proxyName;
+    }
+
+    public String getProxyPort() {
+        return mProxyPort;
+    }
+
+    public void setProxyPort(String proxyPort) {
+        this.mProxyPort = proxyPort;
+    }
+
+    public boolean isUseProxyAuth() {
+        return mUseProxyAuth;
+    }
+
+    public void setUseProxyAuth(boolean useProxyAuth) {
+        this.mUseProxyAuth = useProxyAuth;
+    }
+
+    public String getProxyAuthUser() {
+        return mProxyAuthUser;
+    }
+
+    public void setProxyAuthUser(String proxyAuthUser) {
+        this.mProxyAuthUser = proxyAuthUser;
+    }
+
+    public String getProxyAuthPassword() {
+        return mProxyAuthPassword;
+    }
+
+    public void setProxyAuthPassword(String proxyAuthPassword) {
+        this.mProxyAuthPassword = proxyAuthPassword;
+    }
+
+    public abstract TransportType getTransportType();
+}
diff --git a/app/src/main/java/de/blinkt/openvpn/core/connection/Obfs4Connection.java b/app/src/main/java/de/blinkt/openvpn/core/connection/Obfs4Connection.java
new file mode 100644
index 00000000..790b8b1a
--- /dev/null
+++ b/app/src/main/java/de/blinkt/openvpn/core/connection/Obfs4Connection.java
@@ -0,0 +1,83 @@
+package de.blinkt.openvpn.core.connection;
+
+import org.json.JSONObject;
+
+/**
+ * Created by cyberta on 08.03.19.
+ */
+
+public class Obfs4Connection extends Connection {
+
+    private static final String TAG = Obfs4Connection.class.getName();
+
+
+    private String mObfs4RemoteProxyName = "";
+    private String mObfs4RemoteProxyPort = "";
+    private String mObfs4Certificate = "";
+    private String mObfs4IatMode = "";
+
+    public Obfs4Connection() {
+        setDefaults();
+    }
+
+    public Obfs4Connection(Connection connection) {
+        mObfs4RemoteProxyName = connection.getServerName();
+        setConnectTimeout(connection.getConnectTimeout());
+        setCustomConfiguration(connection.getCustomConfiguration());
+        setUseCustomConfig(connection.isUseCustomConfig());
+
+        setDefaults();
+    }
+
+    private void setDefaults() {
+        setUseUdp(false);
+        setServerName("127.0.0.1");
+        setServerPort("");
+        setProxyName("");
+        setProxyPort("");
+        setProxyAuthUser(null);
+        setProxyAuthPassword(null);
+        setProxyType(ProxyType.NONE);
+        setUseProxyAuth(false);
+    }
+
+    public void setTransportOptions(JSONObject jsonObject) {
+        mObfs4Certificate = jsonObject.optString("cert");
+        mObfs4IatMode = jsonObject.optString("iat-mode");
+    }
+
+    @Override
+    public Connection clone() throws CloneNotSupportedException {
+        return super.clone();
+    }
+
+    @Override
+    public TransportType getTransportType() {
+        return TransportType.OBFS4;
+    }
+
+    public String getmObfs4RemoteProxyName() {
+        return mObfs4RemoteProxyName;
+    }
+
+    public void setObfs4RemoteProxyName(String mObfs4RemoteProxyName) {
+        this.mObfs4RemoteProxyName = mObfs4RemoteProxyName;
+    }
+
+    public String getmObfs4RemoteProxyPort() {
+        return mObfs4RemoteProxyPort;
+    }
+
+    public void setObfs4RemoteProxyPort(String mObfs4RemoteProxyPort) {
+        this.mObfs4RemoteProxyPort = mObfs4RemoteProxyPort;
+    }
+
+    public String getmObfs4Certificate() {
+        return mObfs4Certificate;
+    }
+
+    public String getmObfs4IatMode() {
+        return mObfs4IatMode;
+    }
+
+}
diff --git a/app/src/main/java/de/blinkt/openvpn/core/connection/OpenvpnConnection.java b/app/src/main/java/de/blinkt/openvpn/core/connection/OpenvpnConnection.java
new file mode 100644
index 00000000..3a3fd0c3
--- /dev/null
+++ b/app/src/main/java/de/blinkt/openvpn/core/connection/OpenvpnConnection.java
@@ -0,0 +1,13 @@
+package de.blinkt.openvpn.core.connection;
+
+/**
+ * Created by cyberta on 11.03.19.
+ */
+
+public class OpenvpnConnection extends Connection {
+
+    @Override
+    public TransportType getTransportType() {
+        return TransportType.OPENVPN;
+    }
+}