Merge branch 'integrate_obfsvpn' into 'master'

update bitmaskcore, integrating obfsvpn

See merge request leap/bitmask_android!190

22 files changed, 552 insertions, 175 deletions

diff --git a/app/src/main/java/de/blinkt/openvpn/VpnProfile.java b/app/src/main/java/de/blinkt/openvpn/VpnProfile.java
index c010ef54..7dd75432 100644
--- a/app/src/main/java/de/blinkt/openvpn/VpnProfile.java
+++ b/app/src/main/java/de/blinkt/openvpn/VpnProfile.java
@@ -70,6 +70,8 @@ import se.leap.bitmaskclient.BuildConfig;
 import se.leap.bitmaskclient.R;
 
 import static de.blinkt.openvpn.core.connection.Connection.TransportType.OBFS4;
+import static de.blinkt.openvpn.core.connection.Connection.TransportType.OBFS4_KCP;
+import static de.blinkt.openvpn.core.connection.Connection.TransportType.OPENVPN;
 import static se.leap.bitmaskclient.base.models.Constants.PROVIDER_PROFILE;
 import static se.leap.bitmaskclient.base.utils.ConfigHelper.stringEqual;
 
@@ -191,7 +193,8 @@ public class VpnProfile implements Serializable, Cloneable {
     private int mProfileVersion;
     public boolean mBlockUnusedAddressFamilies = true;
     public String mGatewayIp;
-    public boolean mUsePluggableTransports;
+    private boolean mUseObfs4;
+    private boolean mUseObfs4Kcp;
 
     public VpnProfile(String name, Connection.TransportType transportType) {
         mUuid = UUID.randomUUID();
@@ -200,7 +203,8 @@ public class VpnProfile implements Serializable, Cloneable {
 
         mConnections = new Connection[1];
         mLastUsed = System.currentTimeMillis();
-        mUsePluggableTransports = transportType == OBFS4;
+        mUseObfs4 = transportType == OBFS4;
+        mUseObfs4Kcp = transportType == OBFS4_KCP;
     }
 
     public static String openVpnEscape(String unescaped) {
@@ -266,7 +270,8 @@ public class VpnProfile implements Serializable, Cloneable {
         if (obj instanceof VpnProfile) {
             VpnProfile vp = (VpnProfile) obj;
             return stringEqual(vp.mGatewayIp, mGatewayIp) &&
-                    vp.mUsePluggableTransports == mUsePluggableTransports;
+                    vp.mUseObfs4 == mUseObfs4 &&
+                    vp.mUseObfs4Kcp == mUseObfs4Kcp;
         }
         return false;
     }
@@ -296,6 +301,20 @@ public class VpnProfile implements Serializable, Cloneable {
         mUuid = uuid;
     }
 
+    public boolean usePluggableTransports() {
+        return mUseObfs4Kcp || mUseObfs4;
+    }
+
+    public Connection.TransportType getTransportType() {
+        if (mUseObfs4) {
+            return OBFS4;
+        } else if (mUseObfs4Kcp) {
+            return OBFS4_KCP;
+        } else {
+            return OPENVPN;
+        }
+    }
+
     public String getName() {
         if (TextUtils.isEmpty(mName))
             return "No profile name";
@@ -478,7 +497,7 @@ public class VpnProfile implements Serializable, Cloneable {
             cfg.append(insertFileData("crl-verify", mCrlFilename));
 
         // compression does not work in conjunction with shapeshifter-dispatcher so far
-        if (mUseLzo && !mUsePluggableTransports) {
+        if (mUseLzo && !usePluggableTransports()) {
             cfg.append("comp-lzo\n");
         }
 
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 d624af80..4b394136 100644
--- a/app/src/main/java/de/blinkt/openvpn/core/OpenVPNService.java
+++ b/app/src/main/java/de/blinkt/openvpn/core/OpenVPNService.java
@@ -5,6 +5,12 @@
 
 package de.blinkt.openvpn.core;
 
+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;
+import static se.leap.bitmaskclient.base.models.Constants.PROVIDER_PROFILE;
+import static se.leap.bitmaskclient.base.utils.ConfigHelper.ObfsVpnHelper.useObfsVpn;
+
 import android.Manifest.permission;
 import android.annotation.TargetApi;
 import android.app.Notification;
@@ -47,13 +53,9 @@ import se.leap.bitmaskclient.R;
 import se.leap.bitmaskclient.eip.EipStatus;
 import se.leap.bitmaskclient.eip.VpnNotificationManager;
 import se.leap.bitmaskclient.firewall.FirewallManager;
+import se.leap.bitmaskclient.pluggableTransports.ObfsVpnClient;
 import se.leap.bitmaskclient.pluggableTransports.Shapeshifter;
 
-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;
-import static se.leap.bitmaskclient.base.models.Constants.PROVIDER_PROFILE;
-
 
 public class OpenVPNService extends VpnService implements StateListener, Callback, ByteCountListener, IOpenVPNServiceInternal, VpnNotificationManager.VpnServiceCallback {
     public static final String TAG = OpenVPNService.class.getSimpleName();
@@ -89,6 +91,7 @@ public class OpenVPNService extends VpnService implements StateListener, Callbac
     private Runnable mOpenVPNThread;
     private VpnNotificationManager notificationManager;
     private Shapeshifter shapeshifter;
+    private ObfsVpnClient obfsVpnClient;
     private FirewallManager firewallManager;
 
     private final IBinder mBinder = new IOpenVPNServiceInternal.Stub() {
@@ -241,6 +244,9 @@ public class OpenVPNService extends VpnService implements StateListener, Callbac
                     if (shapeshifter != null) {
                         shapeshifter.stop();
                         shapeshifter = null;
+                    } else if (obfsVpnClient != null && obfsVpnClient.isStarted()) {
+                        obfsVpnClient.stop();
+                        obfsVpnClient = null;
                     }
                     VpnStatus.updateStateString("NOPROCESS", "VPN STOPPED", R.string.state_noprocess, ConnectionStatus.LEVEL_NOTCONNECTED);
                 }
@@ -311,7 +317,7 @@ public class OpenVPNService extends VpnService implements StateListener, Callbac
         VpnStatus.updateStateString("VPN_GENERATE_CONFIG", "", R.string.building_configration, ConnectionStatus.LEVEL_START);
         notificationManager.buildOpenVpnNotification(
                 mProfile != null ? mProfile.mName : "",
-                mProfile != null && mProfile.mUsePluggableTransports,
+                mProfile != null && mProfile.usePluggableTransports(),
                 VpnStatus.getLastCleanLogMessage(this),
                 VpnStatus.getLastCleanLogMessage(this),
                 ConnectionStatus.LEVEL_START,
@@ -410,9 +416,16 @@ public class OpenVPNService extends VpnService implements StateListener, Callbac
         // An old running VPN should now be exited
         mStarting = false;
 
-        if (mProfile.mUsePluggableTransports && connection instanceof Obfs4Connection) {
+        if (mProfile.usePluggableTransports() && connection instanceof Obfs4Connection) {
             Obfs4Connection obfs4Connection = (Obfs4Connection) connection;
-            if (shapeshifter == null) {
+            if (useObfsVpn()) {
+                if (obfsVpnClient != null && obfsVpnClient.isStarted()) {
+                    obfsVpnClient.stop();
+                }
+                obfsVpnClient = new ObfsVpnClient(obfs4Connection.getDispatcherOptions());
+                int runningSocksPort = obfsVpnClient.start();
+                connection.setProxyPort(String.valueOf(runningSocksPort));
+            } else if (shapeshifter == null) {
                 shapeshifter = new Shapeshifter(obfs4Connection.getDispatcherOptions());
                 shapeshifter.start();
             }
@@ -474,6 +487,10 @@ public class OpenVPNService extends VpnService implements StateListener, Callbac
                     Log.d(TAG, "-> stop shapeshifter");
                     shapeshifter.stop();
                     shapeshifter = null;
+                } else if (obfsVpnClient != null && obfsVpnClient.isStarted()) {
+                    Log.d(TAG, "-> stop obfsvpnClient");
+                    obfsVpnClient.stop();
+                    obfsVpnClient = null;
                 }
                 try {
                     Thread.sleep(1000);
@@ -1016,7 +1033,7 @@ public class OpenVPNService extends VpnService implements StateListener, Callbac
 
         notificationManager.buildOpenVpnNotification(
                 mProfile != null ? mProfile.mName : "",
-                mProfile != null && mProfile.mUsePluggableTransports,
+                mProfile != null && mProfile.usePluggableTransports(),
                 VpnStatus.getLastCleanLogMessage(this),
                 VpnStatus.getLastCleanLogMessage(this),
                 level,
@@ -1047,7 +1064,7 @@ public class OpenVPNService extends VpnService implements StateListener, Callbac
                     humanReadableByteCount(diffOut / OpenVPNManagement.mBytecountInterval, true, getResources()));
             notificationManager.buildOpenVpnNotification(
                     mProfile != null ? mProfile.mName : "",
-                    mProfile != null && mProfile.mUsePluggableTransports,
+                    mProfile != null && mProfile.usePluggableTransports(),
                     netstat,
                     null,
                     LEVEL_CONNECTED,
@@ -1091,7 +1108,7 @@ public class OpenVPNService extends VpnService implements StateListener, Callbac
         VpnStatus.updateStateString("NEED", "need " + needed, resid, LEVEL_WAITING_FOR_USER_INPUT);
         notificationManager.buildOpenVpnNotification(
                 mProfile != null ? mProfile.mName : "",
-                mProfile != null && mProfile.mUsePluggableTransports,
+                mProfile != null && mProfile.usePluggableTransports(),
                 getString(resid),
                 getString(resid),
                 LEVEL_WAITING_FOR_USER_INPUT,
diff --git a/app/src/main/java/de/blinkt/openvpn/core/VpnStatus.java b/app/src/main/java/de/blinkt/openvpn/core/VpnStatus.java
index 4fa5a7b6..f28651f3 100644
--- a/app/src/main/java/de/blinkt/openvpn/core/VpnStatus.java
+++ b/app/src/main/java/de/blinkt/openvpn/core/VpnStatus.java
@@ -543,6 +543,6 @@ public class VpnStatus {
     }
 
     public static boolean isUsingBridges() {
-        return lastConnectedProfile != null && lastConnectedProfile.mUsePluggableTransports;
+        return lastConnectedProfile != null && lastConnectedProfile.usePluggableTransports();
     }
 }
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
index 4cb9c0c7..f60e7333 100644
--- a/app/src/main/java/de/blinkt/openvpn/core/connection/Connection.java
+++ b/app/src/main/java/de/blinkt/openvpn/core/connection/Connection.java
@@ -39,7 +39,10 @@ public abstract class Connection implements Serializable, Cloneable {
 
     public enum TransportType {
         OBFS4("obfs4"),
-        OPENVPN("openvpn");
+        OPENVPN("openvpn"),
+        OBFS4_KCP("obfs4-1"),
+
+        PT("metaTransport");
 
         String transport;
 
@@ -51,6 +54,17 @@ public abstract class Connection implements Serializable, Cloneable {
         public String toString() {
             return transport;
         }
+
+        public boolean isPluggableTransport() {
+            return this == OBFS4 || this == OBFS4_KCP || this == PT;
+        }
+
+        public TransportType getMetaType() {
+            if (this == OBFS4 || this == OBFS4_KCP || this == PT) {
+                return PT;
+            }
+            return OPENVPN;
+        }
     }
 
 
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
index 82a7a6aa..5189afcc 100644
--- a/app/src/main/java/de/blinkt/openvpn/core/connection/Obfs4Connection.java
+++ b/app/src/main/java/de/blinkt/openvpn/core/connection/Obfs4Connection.java
@@ -1,10 +1,12 @@
 package de.blinkt.openvpn.core.connection;
 
-import se.leap.bitmaskclient.pluggableTransports.Obfs4Options;
-
+import static se.leap.bitmaskclient.base.utils.ConfigHelper.ObfsVpnHelper.useObfsVpn;
 import static se.leap.bitmaskclient.pluggableTransports.Shapeshifter.DISPATCHER_IP;
 import static se.leap.bitmaskclient.pluggableTransports.Shapeshifter.DISPATCHER_PORT;
 
+import se.leap.bitmaskclient.pluggableTransports.Obfs4Options;
+import se.leap.bitmaskclient.pluggableTransports.ObfsVpnClient;
+
 
 /**
  * Created by cyberta on 08.03.19.
@@ -16,14 +18,24 @@ public class Obfs4Connection extends Connection {
     private Obfs4Options options;
 
     public Obfs4Connection(Obfs4Options options) {
+        if (useObfsVpn()) {
+            setServerName(options.remoteIP);
+            setServerPort(options.remotePort);
+            setProxyName(ObfsVpnClient.SOCKS_IP);
+            setProxyPort(String.valueOf(ObfsVpnClient.SOCKS_PORT.get()));
+            setProxyType(ProxyType.SOCKS5);
+        } else {
+            setServerName(DISPATCHER_IP);
+            setServerPort(DISPATCHER_PORT);
+            setProxyName("");
+            setProxyPort("");
+            setProxyType(ProxyType.NONE);
+        }
+        // while udp/kcp might be used on the wire,
+        // we don't use udp for openvpn in case of a obfs4 connection
         setUseUdp(false);
-        setServerName(DISPATCHER_IP);
-        setServerPort(DISPATCHER_PORT);
-        setProxyName("");
-        setProxyPort("");
         setProxyAuthUser(null);
         setProxyAuthPassword(null);
-        setProxyType(ProxyType.NONE);
         setUseProxyAuth(false);
         this.options = options;
     }
diff --git a/app/src/main/java/se/leap/bitmaskclient/base/fragments/GatewaySelectionFragment.java b/app/src/main/java/se/leap/bitmaskclient/base/fragments/GatewaySelectionFragment.java
index f2c3b2d6..a2bfff7c 100644
--- a/app/src/main/java/se/leap/bitmaskclient/base/fragments/GatewaySelectionFragment.java
+++ b/app/src/main/java/se/leap/bitmaskclient/base/fragments/GatewaySelectionFragment.java
@@ -51,10 +51,10 @@ import se.leap.bitmaskclient.eip.GatewaysManager;
 
 import static android.content.Context.MODE_PRIVATE;
 import static android.view.View.GONE;
-import static android.view.View.INVISIBLE;
 import static android.view.View.VISIBLE;
 import static de.blinkt.openvpn.core.connection.Connection.TransportType.OBFS4;
 import static de.blinkt.openvpn.core.connection.Connection.TransportType.OPENVPN;
+import static de.blinkt.openvpn.core.connection.Connection.TransportType.PT;
 import static se.leap.bitmaskclient.base.MainActivity.ACTION_SHOW_VPN_FRAGMENT;
 import static se.leap.bitmaskclient.base.models.Constants.SHARED_PREFERENCES;
 import static se.leap.bitmaskclient.base.models.Constants.USE_BRIDGES;
@@ -92,7 +92,7 @@ public class GatewaySelectionFragment extends Fragment implements Observer, Loca
         eipStatus = EipStatus.getInstance();
         eipStatus.addObserver(this);
         preferences = getContext().getSharedPreferences(SHARED_PREFERENCES, MODE_PRIVATE);
-        selectedTransport = getUseBridges(preferences) ? OBFS4 : OPENVPN;
+        selectedTransport = getUseBridges(preferences) ? PT : OPENVPN;
         preferences.registerOnSharedPreferenceChangeListener(this);
     }
 
@@ -211,7 +211,7 @@ public class GatewaySelectionFragment extends Fragment implements Observer, Loca
     public void onSharedPreferenceChanged(SharedPreferences sharedPreferences, String key) {
         if (key.equals(USE_BRIDGES)) {
             boolean showBridges = getUseBridges(sharedPreferences);
-            selectedTransport = showBridges ? OBFS4 : OPENVPN;
+            selectedTransport = showBridges ? PT : OPENVPN;
             gatewaysManager.updateTransport(selectedTransport);
             locationListAdapter.updateTransport(selectedTransport, gatewaysManager);
             bridgesHint.setVisibility(showBridges ? VISIBLE : GONE);
diff --git a/app/src/main/java/se/leap/bitmaskclient/base/fragments/NavigationDrawerFragment.java b/app/src/main/java/se/leap/bitmaskclient/base/fragments/NavigationDrawerFragment.java
index 1c859d65..c5593bf7 100644
--- a/app/src/main/java/se/leap/bitmaskclient/base/fragments/NavigationDrawerFragment.java
+++ b/app/src/main/java/se/leap/bitmaskclient/base/fragments/NavigationDrawerFragment.java
@@ -32,7 +32,6 @@ import android.view.View;
 import android.view.ViewGroup;
 
 import androidx.annotation.NonNull;
-import androidx.annotation.StringRes;
 import androidx.appcompat.app.ActionBar;
 import androidx.appcompat.app.ActionBarDrawerToggle;
 import androidx.appcompat.app.AlertDialog;
diff --git a/app/src/main/java/se/leap/bitmaskclient/base/fragments/SettingsFragment.java b/app/src/main/java/se/leap/bitmaskclient/base/fragments/SettingsFragment.java
index f4531ff8..94f737b4 100644
--- a/app/src/main/java/se/leap/bitmaskclient/base/fragments/SettingsFragment.java
+++ b/app/src/main/java/se/leap/bitmaskclient/base/fragments/SettingsFragment.java
@@ -9,12 +9,15 @@ import static se.leap.bitmaskclient.base.models.Constants.PREFER_UDP;
 import static se.leap.bitmaskclient.base.models.Constants.SHARED_PREFERENCES;
 import static se.leap.bitmaskclient.base.models.Constants.USE_BRIDGES;
 import static se.leap.bitmaskclient.base.models.Constants.USE_IPv6_FIREWALL;
+import static se.leap.bitmaskclient.base.utils.ConfigHelper.ObfsVpnHelper.useObfsVpn;
+import static se.leap.bitmaskclient.base.utils.PreferenceHelper.allowExperimentalTransports;
 import static se.leap.bitmaskclient.base.utils.PreferenceHelper.getPreferUDP;
 import static se.leap.bitmaskclient.base.utils.PreferenceHelper.getShowAlwaysOnDialog;
 import static se.leap.bitmaskclient.base.utils.PreferenceHelper.getUseBridges;
 import static se.leap.bitmaskclient.base.utils.PreferenceHelper.getUseSnowflake;
 import static se.leap.bitmaskclient.base.utils.PreferenceHelper.hasSnowflakePrefs;
 import static se.leap.bitmaskclient.base.utils.PreferenceHelper.preferUDP;
+import static se.leap.bitmaskclient.base.utils.PreferenceHelper.setAllowExperimentalTransports;
 import static se.leap.bitmaskclient.base.utils.PreferenceHelper.useBridges;
 import static se.leap.bitmaskclient.base.utils.PreferenceHelper.useSnowflake;
 import static se.leap.bitmaskclient.base.utils.ViewHelper.setActionBarTitle;
@@ -81,6 +84,7 @@ public class SettingsFragment extends Fragment implements SharedPreferences.OnSh
         initFirewallEntry(view);
         initTetheringEntry(view);
         initGatewayPinningEntry(view);
+        initExperimentalTransportsEntry(view);
         setActionBarTitle(this, advanced_settings);
         return view;
     }
@@ -249,6 +253,23 @@ public class SettingsFragment extends Fragment implements SharedPreferences.OnSh
         });
     }
 
+    public void initExperimentalTransportsEntry(View rootView) {
+        IconSwitchEntry experimentalTransports = rootView.findViewById(R.id.experimental_transports);
+        if (useObfsVpn() && ProviderObservable.getInstance().getCurrentProvider().supportsExperimentalPluggableTransports()) {
+            experimentalTransports.setVisibility(VISIBLE);
+            experimentalTransports.setChecked(allowExperimentalTransports(this.getContext()));
+            experimentalTransports.setOnCheckedChangeListener((buttonView, isChecked) -> {
+                if (!buttonView.isPressed()) {
+                    return;
+                }
+                setAllowExperimentalTransports(getContext(), isChecked);
+            });
+        } else {
+            experimentalTransports.setVisibility(GONE);
+        }
+
+    }
+
     public void showTetheringAlert() {
         try {
 
diff --git a/app/src/main/java/se/leap/bitmaskclient/base/models/Constants.java b/app/src/main/java/se/leap/bitmaskclient/base/models/Constants.java
index bde909ba..b34a31eb 100644
--- a/app/src/main/java/se/leap/bitmaskclient/base/models/Constants.java
+++ b/app/src/main/java/se/leap/bitmaskclient/base/models/Constants.java
@@ -44,6 +44,7 @@ public interface Constants {
     String USE_SNOWFLAKE = "use_snowflake";
     String PREFER_UDP = "prefer_UDP";
     String GATEWAY_PINNING = "gateway_pinning";
+    String ALLOW_EXPERIMENTAL_TRANSPORTS = "allow_experimental_transports";
 
 
      //////////////////////////////////////////////
@@ -163,6 +164,7 @@ public interface Constants {
     String IP_ADDRESS = "ip_address";
     String IP_ADDRESS6 = "ip_address6";
     String REMOTE = "remote";
+    String SOCKS_PROXY = "socks-proxy";
     String PORTS = "ports";
     String PROTOCOLS = "protocols";
     String UDP = "udp";
diff --git a/app/src/main/java/se/leap/bitmaskclient/base/models/Location.java b/app/src/main/java/se/leap/bitmaskclient/base/models/Location.java
index 064f25c0..26f6b14a 100644
--- a/app/src/main/java/se/leap/bitmaskclient/base/models/Location.java
+++ b/app/src/main/java/se/leap/bitmaskclient/base/models/Location.java
@@ -21,10 +21,7 @@ import androidx.annotation.NonNull;
 
 import java.util.Comparator;
 import java.util.HashMap;
-import java.util.HashSet;
-import java.util.function.ToDoubleFunction;
 
-import de.blinkt.openvpn.core.connection.Connection;
 import de.blinkt.openvpn.core.connection.Connection.TransportType;
 
 public class Location implements Cloneable {
@@ -50,27 +47,27 @@ public class Location implements Cloneable {
     }
 
     public boolean supportsTransport(TransportType transportType) {
-        return numberOfGateways.containsKey(transportType);
+        return numberOfGateways.containsKey(transportType.getMetaType());
     }
 
     public void setAverageLoad(TransportType transportType, double load) {
-        averageLoad.put(transportType, load);
+        averageLoad.put(transportType.getMetaType(), load);
     }
 
     public double getAverageLoad(TransportType transportType) {
-        if (averageLoad.containsKey(transportType)) {
-            return averageLoad.get(transportType);
+        if (averageLoad.containsKey(transportType.getMetaType())) {
+            return averageLoad.get(transportType.getMetaType());
         }
         return 0;
     }
 
     public void setNumberOfGateways(TransportType transportType, int numbers) {
-        numberOfGateways.put(transportType, numbers);
+        numberOfGateways.put(transportType.getMetaType(), numbers);
     }
 
     public int getNumberOfGateways(TransportType transportType) {
-        if (numberOfGateways.containsKey(transportType)) {
-            return numberOfGateways.get(transportType);
+        if (numberOfGateways.containsKey(transportType.getMetaType())) {
+            return numberOfGateways.get(transportType.getMetaType());
         }
         return 0;
     }
@@ -112,7 +109,7 @@ public class Location implements Cloneable {
     public static class SortByAverageLoad implements Comparator<Location> {
         TransportType transportType;
         public SortByAverageLoad(TransportType transportType) {
-            this.transportType = transportType;
+            this.transportType = transportType.getMetaType();
         }
 
         @Override
diff --git a/app/src/main/java/se/leap/bitmaskclient/base/models/Pair.java b/app/src/main/java/se/leap/bitmaskclient/base/models/Pair.java
new file mode 100644
index 00000000..e2ef4622
--- /dev/null
+++ b/app/src/main/java/se/leap/bitmaskclient/base/models/Pair.java
@@ -0,0 +1,57 @@
+package se.leap.bitmaskclient.base.models;
+
+import java.util.Objects;
+
+/**
+ * Container to ease passing around a tuple of two objects. This object provides a sensible
+ * implementation of equals(), returning true if equals() is true on each of the contained
+ * objects.
+ */
+public class Pair<F, S> {
+    public final F first;
+    public final S second;
+
+    /**
+     * Constructor for a Pair.
+     *
+     * @param first the first object in the Pair
+     * @param second the second object in the pair
+     */
+    public Pair(F first, S second) {
+        this.first = first;
+        this.second = second;
+    }
+
+    /**
+     * Checks the two objects for equality by delegating to their respective
+     * {@link Object#equals(Object)} methods.
+     *
+     * @param o the {@link Pair} to which this one is to be checked for equality
+     * @return true if the underlying objects of the Pair are both considered
+     *         equal
+     */
+    @Override
+    public boolean equals(Object o) {
+        if (!(o instanceof Pair)) {
+            return false;
+        }
+        Pair<?, ?> p = (Pair<?, ?>) o;
+        return Objects.equals(p.first, first) && Objects.equals(p.second, second);
+    }
+
+    /**
+     * Compute a hash code using the hash codes of the underlying objects
+     *
+     * @return a hashcode of the Pair
+     */
+    @Override
+    public int hashCode() {
+        return (first == null ? 0 : first.hashCode()) ^ (second == null ? 0 : second.hashCode());
+    }
+
+    @Override
+    public String toString() {
+        return "Pair{" + String.valueOf(first) + " " + String.valueOf(second) + "}";
+    }
+
+}
diff --git a/app/src/main/java/se/leap/bitmaskclient/base/models/Provider.java b/app/src/main/java/se/leap/bitmaskclient/base/models/Provider.java
index 02a9694a..7b8f22af 100644
--- a/app/src/main/java/se/leap/bitmaskclient/base/models/Provider.java
+++ b/app/src/main/java/se/leap/bitmaskclient/base/models/Provider.java
@@ -30,6 +30,7 @@ import java.net.URL;
 import java.util.Locale;
 
 import static de.blinkt.openvpn.core.connection.Connection.TransportType.OBFS4;
+import static de.blinkt.openvpn.core.connection.Connection.TransportType.OBFS4_KCP;
 import static se.leap.bitmaskclient.base.models.Constants.CAPABILITIES;
 import static se.leap.bitmaskclient.base.models.Constants.GATEWAYS;
 import static se.leap.bitmaskclient.base.models.Constants.LOCATIONS;
@@ -37,8 +38,12 @@ import static se.leap.bitmaskclient.base.models.Constants.PROVIDER_ALLOWED_REGIS
 import static se.leap.bitmaskclient.base.models.Constants.PROVIDER_ALLOW_ANONYMOUS;
 import static se.leap.bitmaskclient.base.models.Constants.TRANSPORT;
 import static se.leap.bitmaskclient.base.models.Constants.TYPE;
+import static se.leap.bitmaskclient.base.utils.ConfigHelper.ObfsVpnHelper.useObfsVpn;
 import static se.leap.bitmaskclient.providersetup.ProviderAPI.ERRORS;
 
+import de.blinkt.openvpn.core.connection.Connection;
+import de.blinkt.openvpn.core.connection.Connection.TransportType;
+
 /**
  * @author Sean Leonard <meanderingcode@aetherislands.net>
  * @author Parménides GV <parmegv@sdf.org>
@@ -161,6 +166,17 @@ public final class Provider implements Parcelable {
     }
 
     public boolean supportsPluggableTransports() {
+        if (useObfsVpn()) {
+            return supportsTransports(new TransportType[]{OBFS4, OBFS4_KCP});
+        }
+        return supportsTransports(new TransportType[]{OBFS4});
+    }
+
+    public boolean supportsExperimentalPluggableTransports() {
+        return supportsTransports(new TransportType[]{OBFS4_KCP});
+    }
+
+    private boolean supportsTransports(TransportType[] transportTypes) {
         try {
             JSONArray gatewayJsons = eipServiceJson.getJSONArray(GATEWAYS);
             for (int i = 0; i < gatewayJsons.length(); i++) {
@@ -168,15 +184,18 @@ public final class Provider implements Parcelable {
                         getJSONObject(CAPABILITIES).
                         getJSONArray(TRANSPORT);
                 for (int j = 0; j < transports.length(); j++) {
-                    if (OBFS4.toString().equals(transports.getJSONObject(j).getString(TYPE))) {
-                        return true;
+                    String supportedTransportType = transports.getJSONObject(j).getString(TYPE);
+                    for (TransportType transportType : transportTypes) {
+                        if (transportType.toString().equals(supportedTransportType)) {
+                            return true;
+                        }
                     }
                 }
             }
         } catch (Exception e) {
-           // ignore
+            // ignore
         }
-       return false;
+        return false;
     }
 
     public String getIpForHostname(String host) {
diff --git a/app/src/main/java/se/leap/bitmaskclient/base/utils/ConfigHelper.java b/app/src/main/java/se/leap/bitmaskclient/base/utils/ConfigHelper.java
index ca1261a8..8ac5baf0 100644
--- a/app/src/main/java/se/leap/bitmaskclient/base/utils/ConfigHelper.java
+++ b/app/src/main/java/se/leap/bitmaskclient/base/utils/ConfigHelper.java
@@ -274,4 +274,11 @@ public class ConfigHelper {
         return matcher.matches();
     }
 
+    // ObfsVpnHelper class allows us to mock BuildConfig.use_obfsvpn while
+    // not mocking the whole ConfigHelper class
+    public static class ObfsVpnHelper {
+        public static boolean useObfsVpn() {
+            return BuildConfig.use_obfsvpn;
+        }
+    }
 }
diff --git a/app/src/main/java/se/leap/bitmaskclient/base/utils/PreferenceHelper.java b/app/src/main/java/se/leap/bitmaskclient/base/utils/PreferenceHelper.java
index 08bfbdc3..3a2cf754 100644
--- a/app/src/main/java/se/leap/bitmaskclient/base/utils/PreferenceHelper.java
+++ b/app/src/main/java/se/leap/bitmaskclient/base/utils/PreferenceHelper.java
@@ -1,25 +1,7 @@
 package se.leap.bitmaskclient.base.utils;
 
-import android.content.Context;
-import android.content.SharedPreferences;
-import android.preference.Preference;
-
-import androidx.annotation.NonNull;
-import androidx.annotation.WorkerThread;
-
-import org.json.JSONException;
-import org.json.JSONObject;
-
-import java.net.MalformedURLException;
-import java.net.URL;
-import java.util.HashSet;
-import java.util.Set;
-
-import de.blinkt.openvpn.VpnProfile;
-import se.leap.bitmaskclient.base.models.Provider;
-import se.leap.bitmaskclient.tor.TorStatusObservable;
-
 import static android.content.Context.MODE_PRIVATE;
+import static se.leap.bitmaskclient.base.models.Constants.ALLOW_EXPERIMENTAL_TRANSPORTS;
 import static se.leap.bitmaskclient.base.models.Constants.ALLOW_TETHERING_BLUETOOTH;
 import static se.leap.bitmaskclient.base.models.Constants.ALLOW_TETHERING_USB;
 import static se.leap.bitmaskclient.base.models.Constants.ALLOW_TETHERING_WIFI;
@@ -42,6 +24,24 @@ import static se.leap.bitmaskclient.base.models.Constants.USE_BRIDGES;
 import static se.leap.bitmaskclient.base.models.Constants.USE_IPv6_FIREWALL;
 import static se.leap.bitmaskclient.base.models.Constants.USE_SNOWFLAKE;
 
+import android.content.Context;
+import android.content.SharedPreferences;
+
+import androidx.annotation.NonNull;
+import androidx.annotation.WorkerThread;
+
+import org.json.JSONException;
+import org.json.JSONObject;
+
+import java.net.MalformedURLException;
+import java.net.URL;
+import java.util.HashSet;
+import java.util.Set;
+
+import de.blinkt.openvpn.VpnProfile;
+import se.leap.bitmaskclient.base.models.Provider;
+import se.leap.bitmaskclient.tor.TorStatusObservable;
+
 /**
  * Created by cyberta on 18.03.18.
  */
@@ -238,6 +238,14 @@ public class PreferenceHelper {
         return getBoolean(context, SHOW_EXPERIMENTAL, false);
     }
 
+    public static void setAllowExperimentalTransports(Context context, boolean show) {
+        putBoolean(context, ALLOW_EXPERIMENTAL_TRANSPORTS, show);
+    }
+
+    public static boolean allowExperimentalTransports(Context context) {
+        return getBoolean(context, ALLOW_EXPERIMENTAL_TRANSPORTS, false);
+    }
+
     public static void setUseIPv6Firewall(Context context, boolean useFirewall) {
         putBoolean(context, USE_IPv6_FIREWALL, useFirewall);
     }
diff --git a/app/src/main/java/se/leap/bitmaskclient/base/views/SelectLocationEntry.java b/app/src/main/java/se/leap/bitmaskclient/base/views/SelectLocationEntry.java
index 3d4f93ff..554fe958 100644
--- a/app/src/main/java/se/leap/bitmaskclient/base/views/SelectLocationEntry.java
+++ b/app/src/main/java/se/leap/bitmaskclient/base/views/SelectLocationEntry.java
@@ -6,7 +6,6 @@ import android.util.AttributeSet;
 import android.view.LayoutInflater;
 import android.view.View;
 import android.widget.LinearLayout;
-import android.widget.RelativeLayout;
 
 import androidx.appcompat.widget.AppCompatImageView;
 import androidx.appcompat.widget.AppCompatTextView;
@@ -71,7 +70,7 @@ public class SelectLocationEntry extends LinearLayout {
         boolean supportsSelectedTransport = location.supportsTransport(transportType);
         locationText.setVisibility(hasData ? VISIBLE : GONE);
         locationIndicator.setVisibility(hasData ? VISIBLE : GONE);
-        bridgesView.setVisibility(transportType == OBFS4 && supportsSelectedTransport ? VISIBLE : GONE);
+        bridgesView.setVisibility(transportType.isPluggableTransport()  && supportsSelectedTransport ? VISIBLE : GONE);
         locationText.setText(location.getName());
         locationIndicator.setLoad(Load.getLoadByValue(location.getAverageLoad(transportType)));
         selectedView.setChecked(location.selected);
diff --git a/app/src/main/java/se/leap/bitmaskclient/eip/EIP.java b/app/src/main/java/se/leap/bitmaskclient/eip/EIP.java
index 46f91781..b3efd21f 100644
--- a/app/src/main/java/se/leap/bitmaskclient/eip/EIP.java
+++ b/app/src/main/java/se/leap/bitmaskclient/eip/EIP.java
@@ -16,6 +16,36 @@
  */
 package se.leap.bitmaskclient.eip;
 
+import static android.app.Activity.RESULT_CANCELED;
+import static android.app.Activity.RESULT_OK;
+import static se.leap.bitmaskclient.R.string.vpn_certificate_is_invalid;
+import static se.leap.bitmaskclient.R.string.warning_client_parsing_error_gateways;
+import static se.leap.bitmaskclient.base.models.Constants.BROADCAST_GATEWAY_SETUP_OBSERVER_EVENT;
+import static se.leap.bitmaskclient.base.models.Constants.BROADCAST_RESULT_KEY;
+import static se.leap.bitmaskclient.base.models.Constants.CLEARLOG;
+import static se.leap.bitmaskclient.base.models.Constants.EIP_ACTION_CHECK_CERT_VALIDITY;
+import static se.leap.bitmaskclient.base.models.Constants.EIP_ACTION_IS_RUNNING;
+import static se.leap.bitmaskclient.base.models.Constants.EIP_ACTION_LAUNCH_VPN;
+import static se.leap.bitmaskclient.base.models.Constants.EIP_ACTION_START;
+import static se.leap.bitmaskclient.base.models.Constants.EIP_ACTION_START_ALWAYS_ON_VPN;
+import static se.leap.bitmaskclient.base.models.Constants.EIP_ACTION_START_BLOCKING_VPN;
+import static se.leap.bitmaskclient.base.models.Constants.EIP_ACTION_STOP;
+import static se.leap.bitmaskclient.base.models.Constants.EIP_ACTION_STOP_BLOCKING_VPN;
+import static se.leap.bitmaskclient.base.models.Constants.EIP_EARLY_ROUTES;
+import static se.leap.bitmaskclient.base.models.Constants.EIP_N_CLOSEST_GATEWAY;
+import static se.leap.bitmaskclient.base.models.Constants.EIP_RECEIVER;
+import static se.leap.bitmaskclient.base.models.Constants.EIP_RESTART_ON_BOOT;
+import static se.leap.bitmaskclient.base.models.Constants.PROVIDER_PROFILE;
+import static se.leap.bitmaskclient.base.models.Constants.PROVIDER_VPN_CERTIFICATE;
+import static se.leap.bitmaskclient.base.models.Constants.SHARED_PREFERENCES;
+import static se.leap.bitmaskclient.base.utils.ConfigHelper.ensureNotOnMainThread;
+import static se.leap.bitmaskclient.base.utils.PreferenceHelper.getPreferredCity;
+import static se.leap.bitmaskclient.eip.EIP.EIPErrors.ERROR_INVALID_PROFILE;
+import static se.leap.bitmaskclient.eip.EIP.EIPErrors.ERROR_INVALID_VPN_CERTIFICATE;
+import static se.leap.bitmaskclient.eip.EIP.EIPErrors.ERROR_VPN_PREPARE;
+import static se.leap.bitmaskclient.eip.EIP.EIPErrors.NO_MORE_GATEWAYS;
+import static se.leap.bitmaskclient.eip.EipResultBroadcast.tellToReceiverOrBroadcast;
+
 import android.annotation.SuppressLint;
 import android.content.ComponentName;
 import android.content.Context;
@@ -31,6 +61,7 @@ import android.os.ResultReceiver;
 import android.util.Log;
 
 import androidx.annotation.NonNull;
+import androidx.annotation.Nullable;
 import androidx.annotation.StringRes;
 import androidx.annotation.WorkerThread;
 import androidx.core.app.JobIntentService;
@@ -57,42 +88,10 @@ import de.blinkt.openvpn.core.connection.Connection;
 import se.leap.bitmaskclient.R;
 import se.leap.bitmaskclient.base.OnBootReceiver;
 import se.leap.bitmaskclient.base.models.Provider;
+import se.leap.bitmaskclient.base.models.Pair;
 import se.leap.bitmaskclient.base.models.ProviderObservable;
 import se.leap.bitmaskclient.base.utils.PreferenceHelper;
 
-import static android.app.Activity.RESULT_CANCELED;
-import static android.app.Activity.RESULT_OK;
-import static de.blinkt.openvpn.core.connection.Connection.TransportType.OBFS4;
-import static de.blinkt.openvpn.core.connection.Connection.TransportType.OPENVPN;
-import static se.leap.bitmaskclient.R.string.vpn_certificate_is_invalid;
-import static se.leap.bitmaskclient.R.string.warning_client_parsing_error_gateways;
-import static se.leap.bitmaskclient.base.models.Constants.BROADCAST_GATEWAY_SETUP_OBSERVER_EVENT;
-import static se.leap.bitmaskclient.base.models.Constants.BROADCAST_RESULT_KEY;
-import static se.leap.bitmaskclient.base.models.Constants.CLEARLOG;
-import static se.leap.bitmaskclient.base.models.Constants.EIP_ACTION_CHECK_CERT_VALIDITY;
-import static se.leap.bitmaskclient.base.models.Constants.EIP_ACTION_IS_RUNNING;
-import static se.leap.bitmaskclient.base.models.Constants.EIP_ACTION_LAUNCH_VPN;
-import static se.leap.bitmaskclient.base.models.Constants.EIP_ACTION_START;
-import static se.leap.bitmaskclient.base.models.Constants.EIP_ACTION_START_ALWAYS_ON_VPN;
-import static se.leap.bitmaskclient.base.models.Constants.EIP_ACTION_START_BLOCKING_VPN;
-import static se.leap.bitmaskclient.base.models.Constants.EIP_ACTION_STOP;
-import static se.leap.bitmaskclient.base.models.Constants.EIP_ACTION_STOP_BLOCKING_VPN;
-import static se.leap.bitmaskclient.base.models.Constants.EIP_EARLY_ROUTES;
-import static se.leap.bitmaskclient.base.models.Constants.EIP_N_CLOSEST_GATEWAY;
-import static se.leap.bitmaskclient.base.models.Constants.EIP_RECEIVER;
-import static se.leap.bitmaskclient.base.models.Constants.EIP_RESTART_ON_BOOT;
-import static se.leap.bitmaskclient.base.models.Constants.PROVIDER_PROFILE;
-import static se.leap.bitmaskclient.base.models.Constants.PROVIDER_VPN_CERTIFICATE;
-import static se.leap.bitmaskclient.base.models.Constants.SHARED_PREFERENCES;
-import static se.leap.bitmaskclient.base.utils.ConfigHelper.ensureNotOnMainThread;
-import static se.leap.bitmaskclient.base.utils.PreferenceHelper.getPreferredCity;
-import static se.leap.bitmaskclient.base.utils.PreferenceHelper.getUseBridges;
-import static se.leap.bitmaskclient.eip.EIP.EIPErrors.ERROR_INVALID_PROFILE;
-import static se.leap.bitmaskclient.eip.EIP.EIPErrors.ERROR_INVALID_VPN_CERTIFICATE;
-import static se.leap.bitmaskclient.eip.EIP.EIPErrors.ERROR_VPN_PREPARE;
-import static se.leap.bitmaskclient.eip.EIP.EIPErrors.NO_MORE_GATEWAYS;
-import static se.leap.bitmaskclient.eip.EipResultBroadcast.tellToReceiverOrBroadcast;
-
 /**
  * EIP is the abstract base class for interacting with and managing the Encrypted
  * Internet Proxy connection.  Connections are started, stopped, and queried through
@@ -256,8 +255,8 @@ public final class EIP extends JobIntentService implements Observer {
             return;
         }
 
-        Gateway gateway = gatewaysManager.select(nClosestGateway);
-        launchActiveGateway(gateway, nClosestGateway, result);
+        Pair<Gateway, Connection.TransportType> gatewayTransportTypePair = gatewaysManager.select(nClosestGateway);
+        launchActiveGateway(gatewayTransportTypePair, nClosestGateway, result);
         if (result.containsKey(BROADCAST_RESULT_KEY) && !result.getBoolean(BROADCAST_RESULT_KEY)) {
             tellToReceiverOrBroadcast(this, EIP_ACTION_START, RESULT_CANCELED, result);
         } else {
@@ -271,7 +270,7 @@ public final class EIP extends JobIntentService implements Observer {
      */
     private void startEIPAlwaysOnVpn() {
         GatewaysManager gatewaysManager = new GatewaysManager(getApplicationContext());
-        Gateway gateway = gatewaysManager.select(0);
+        Pair<Gateway, Connection.TransportType> gatewayTransportTypePair = gatewaysManager.select(0);
         Bundle result = new Bundle();
 
         if (shouldUpdateVPNCertificate()) {
@@ -280,7 +279,7 @@ public final class EIP extends JobIntentService implements Observer {
             ProviderObservable.getInstance().updateProvider(p);
         }
 
-        launchActiveGateway(gateway, 0, result);
+        launchActiveGateway(gatewayTransportTypePair, 0, result);
         if (result.containsKey(BROADCAST_RESULT_KEY) && !result.getBoolean(BROADCAST_RESULT_KEY)){
             VpnStatus.logWarning("ALWAYS-ON VPN: " + getString(R.string.no_vpn_profiles_defined));
         }
@@ -324,13 +323,13 @@ public final class EIP extends JobIntentService implements Observer {
     /**
      * starts the VPN and connects to the given gateway
      *
-     * @param gateway to connect to
+     * @param gatewayTransportTypePair Pair of Gateway and associated transport used to connect
      */
-    private void launchActiveGateway(Gateway gateway, int nClosestGateway, Bundle result) {
+    private void launchActiveGateway(@Nullable Pair<Gateway, Connection.TransportType> gatewayTransportTypePair, int nClosestGateway, Bundle result) {
         VpnProfile profile;
-        Connection.TransportType transportType = getUseBridges(this) ? OBFS4 : OPENVPN;
-        if (gateway == null ||
-                (profile = gateway.getProfile(transportType)) == null) {
+
+        if (gatewayTransportTypePair == null || gatewayTransportTypePair.first == null ||
+                (profile = gatewayTransportTypePair.first.getProfile(gatewayTransportTypePair.second)) == null) {
             String preferredLocation = getPreferredCity(getApplicationContext());
             if (preferredLocation != null) {
                 setErrorResult(result, NO_MORE_GATEWAYS.toString(), getStringResourceForNoMoreGateways(), getString(R.string.app_name), preferredLocation);
diff --git a/app/src/main/java/se/leap/bitmaskclient/eip/Gateway.java b/app/src/main/java/se/leap/bitmaskclient/eip/Gateway.java
index 60507363..e9281609 100644
--- a/app/src/main/java/se/leap/bitmaskclient/eip/Gateway.java
+++ b/app/src/main/java/se/leap/bitmaskclient/eip/Gateway.java
@@ -16,6 +16,17 @@
  */
 package se.leap.bitmaskclient.eip;
 
+import static se.leap.bitmaskclient.base.models.Constants.FULLNESS;
+import static se.leap.bitmaskclient.base.models.Constants.HOST;
+import static se.leap.bitmaskclient.base.models.Constants.IP_ADDRESS;
+import static se.leap.bitmaskclient.base.models.Constants.LOCATION;
+import static se.leap.bitmaskclient.base.models.Constants.LOCATIONS;
+import static se.leap.bitmaskclient.base.models.Constants.NAME;
+import static se.leap.bitmaskclient.base.models.Constants.OPENVPN_CONFIGURATION;
+import static se.leap.bitmaskclient.base.models.Constants.OVERLOAD;
+import static se.leap.bitmaskclient.base.models.Constants.TIMEZONE;
+import static se.leap.bitmaskclient.base.models.Constants.VERSION;
+
 import android.content.Context;
 
 import androidx.annotation.NonNull;
@@ -36,17 +47,6 @@ import de.blinkt.openvpn.core.connection.Connection;
 import se.leap.bitmaskclient.base.utils.ConfigHelper;
 import se.leap.bitmaskclient.base.utils.PreferenceHelper;
 
-import static se.leap.bitmaskclient.base.models.Constants.FULLNESS;
-import static se.leap.bitmaskclient.base.models.Constants.HOST;
-import static se.leap.bitmaskclient.base.models.Constants.IP_ADDRESS;
-import static se.leap.bitmaskclient.base.models.Constants.LOCATION;
-import static se.leap.bitmaskclient.base.models.Constants.LOCATIONS;
-import static se.leap.bitmaskclient.base.models.Constants.NAME;
-import static se.leap.bitmaskclient.base.models.Constants.OPENVPN_CONFIGURATION;
-import static se.leap.bitmaskclient.base.models.Constants.OVERLOAD;
-import static se.leap.bitmaskclient.base.models.Constants.TIMEZONE;
-import static se.leap.bitmaskclient.base.models.Constants.VERSION;
-
 /**
  * Gateway provides objects defining gateways and their metadata.
  * Each instance contains a VpnProfile for OpenVPN specific data and member
@@ -175,7 +175,8 @@ public class Gateway {
     private @NonNull HashMap<Connection.TransportType, VpnProfile> createVPNProfiles(Context context)
             throws ConfigParser.ConfigParseError, IOException, JSONException {
         boolean preferUDP = PreferenceHelper.getPreferUDP(context);
-        VpnConfigGenerator vpnConfigurationGenerator = new VpnConfigGenerator(generalConfiguration, secrets, gateway, apiVersion, preferUDP);
+        boolean allowExperimentalTransports = PreferenceHelper.allowExperimentalTransports(context);
+        VpnConfigGenerator vpnConfigurationGenerator = new VpnConfigGenerator(generalConfiguration, secrets, gateway, apiVersion, preferUDP, allowExperimentalTransports);
         HashMap<Connection.TransportType, VpnProfile> profiles = vpnConfigurationGenerator.generateVpnProfiles();
         addProfileInfos(context, profiles);
         return profiles;
@@ -194,6 +195,9 @@ public class Gateway {
     }
 
     public boolean supportsTransport(Connection.TransportType transportType) {
+        if (transportType == Connection.TransportType.PT) {
+            return supportsPluggableTransports();
+        }
         return vpnProfiles.get(transportType) != null;
     }
 
@@ -201,6 +205,15 @@ public class Gateway {
         return new HashSet<>(vpnProfiles.keySet());
     }
 
+    public boolean supportsPluggableTransports() {
+        for (Connection.TransportType transportType : vpnProfiles.keySet()) {
+            if (transportType.isPluggableTransport() && vpnProfiles.get(transportType) != null) {
+                return true;
+            }
+        }
+        return false;
+    }
+
     public int getTimezone() {
         return timezone;
     }
diff --git a/app/src/main/java/se/leap/bitmaskclient/eip/GatewaysManager.java b/app/src/main/java/se/leap/bitmaskclient/eip/GatewaysManager.java
index a11c7e34..db7dd38c 100644
--- a/app/src/main/java/se/leap/bitmaskclient/eip/GatewaysManager.java
+++ b/app/src/main/java/se/leap/bitmaskclient/eip/GatewaysManager.java
@@ -43,12 +43,15 @@ import de.blinkt.openvpn.core.connection.Connection;
 import de.blinkt.openvpn.core.connection.Connection.TransportType;
 import se.leap.bitmaskclient.BuildConfig;
 import se.leap.bitmaskclient.base.models.Location;
+import se.leap.bitmaskclient.base.models.Pair;
 import se.leap.bitmaskclient.base.models.Provider;
 import se.leap.bitmaskclient.base.models.ProviderObservable;
 import se.leap.bitmaskclient.base.utils.PreferenceHelper;
 
 import static de.blinkt.openvpn.core.connection.Connection.TransportType.OBFS4;
+import static de.blinkt.openvpn.core.connection.Connection.TransportType.OBFS4_KCP;
 import static de.blinkt.openvpn.core.connection.Connection.TransportType.OPENVPN;
+import static de.blinkt.openvpn.core.connection.Connection.TransportType.PT;
 import static se.leap.bitmaskclient.base.models.Constants.GATEWAYS;
 import static se.leap.bitmaskclient.base.models.Constants.HOST;
 import static se.leap.bitmaskclient.base.models.Constants.PROVIDER_PRIVATE_KEY;
@@ -111,18 +114,18 @@ public class GatewaysManager {
      * select closest Gateway
       * @return the n closest Gateway
      */
-    public Gateway select(int nClosest) {
+    public Pair<Gateway, TransportType> select(int nClosest) {
         String selectedCity = getPreferredCity(context);
         return select(nClosest, selectedCity);
     }
 
-    public Gateway select(int nClosest, String city) {
-        TransportType transportType = getUseBridges(context) ? OBFS4 : OPENVPN;
+    public Pair<Gateway, TransportType> select(int nClosest, String city) {
+        TransportType[] transportTypes = getUseBridges(context) ? new TransportType[]{OBFS4, OBFS4_KCP} : new TransportType[]{OPENVPN};
         if (presortedList.size() > 0) {
-            return getGatewayFromPresortedList(nClosest, transportType, city);
+            return getGatewayFromPresortedList(nClosest, transportTypes, city);
         }
 
-        return getGatewayFromTimezoneCalculation(nClosest, transportType, city);
+        return getGatewayFromTimezoneCalculation(nClosest, transportTypes, city);
     }
 
     public void updateTransport(TransportType transportType) {
@@ -158,7 +161,7 @@ public class GatewaysManager {
             } else {
                 int index = locationNames.get(gateway.getName());
                 Location location = locations.get(index);
-                updateLocation(location, gateway, OBFS4);
+                updateLocation(location, gateway, PT);
                 updateLocation(location, gateway, OPENVPN);
                 locations.set(index, location);
             }
@@ -173,9 +176,9 @@ public class GatewaysManager {
     private Location initLocation(String name, Gateway gateway, String preferredCity) {
         HashMap<TransportType, Double> averageLoadMap = new HashMap<>();
         HashMap<TransportType, Integer> numberOfGatewaysMap = new HashMap<>();
-        if (gateway.getSupportedTransports().contains(OBFS4)) {
-            averageLoadMap.put(OBFS4, gateway.getFullness());
-            numberOfGatewaysMap.put(OBFS4, 1);
+        if (gateway.supportsPluggableTransports()) {
+            averageLoadMap.put(PT, gateway.getFullness());
+            numberOfGatewaysMap.put(PT, 1);
         }
         if (gateway.getSupportedTransports().contains(OPENVPN)) {
             averageLoadMap.put(OPENVPN, gateway.getFullness());
@@ -189,7 +192,7 @@ public class GatewaysManager {
     }
 
     private void updateLocation(Location location, Gateway gateway, Connection.TransportType transportType) {
-        if (gateway.getSupportedTransports().contains(transportType)) {
+        if (gateway.supportsTransport(transportType)) {
             double averageLoad = location.getAverageLoad(transportType);
             int numberOfGateways = location.getNumberOfGateways(transportType);
             averageLoad = (numberOfGateways * averageLoad + gateway.getFullness()) / (numberOfGateways + 1);
@@ -218,35 +221,40 @@ public class GatewaysManager {
         return Load.getLoadByValue(location.getAverageLoad(transportType));
     }
 
-    private Gateway getGatewayFromTimezoneCalculation(int nClosest, TransportType transportType, @Nullable String city) {
+    private Pair<Gateway, TransportType> getGatewayFromTimezoneCalculation(int nClosest, TransportType[] transportTypes, @Nullable String city) {
         List<Gateway> list = new ArrayList<>(gateways.values());
         GatewaySelector gatewaySelector = new GatewaySelector(list);
         Gateway gateway;
         int found  = 0;
         int i = 0;
         while ((gateway = gatewaySelector.select(i)) != null) {
-            if ((city == null && gateway.supportsTransport(transportType)) ||
-                    (gateway.getName().equals(city) && gateway.supportsTransport(transportType))) {
-                if (found == nClosest) {
-                    return gateway;
+            for (TransportType transportType : transportTypes) {
+                if ((city == null && gateway.supportsTransport(transportType)) ||
+                        (gateway.getName().equals(city) && gateway.supportsTransport(transportType))) {
+                    if (found == nClosest) {
+                        return new Pair<>(gateway, transportType);
+                    }
+                    found++;
                 }
-                found++;
             }
             i++;
         }
         return null;
     }
 
-    private Gateway getGatewayFromPresortedList(int nClosest, TransportType transportType, @Nullable String city) {
+    private Pair<Gateway, TransportType> getGatewayFromPresortedList(int nClosest, TransportType[] transportTypes, @Nullable String city) {
         int found = 0;
         for (Gateway gateway : presortedList) {
-            if ((city == null && gateway.supportsTransport(transportType)) ||
-                    (gateway.getName().equals(city) && gateway.supportsTransport(transportType))) {
-                if (found == nClosest) {
-                    return gateway;
+            for (TransportType transportType : transportTypes) {
+                if ((city == null && gateway.supportsTransport(transportType)) ||
+                        (gateway.getName().equals(city) && gateway.supportsTransport(transportType))) {
+                    if (found == nClosest) {
+                        return new Pair<>(gateway, transportType);
+                    }
+                    found++;
                 }
-                found++;
             }
+
         }
         return null;
     }
@@ -265,7 +273,7 @@ public class GatewaysManager {
     }
     
     private int getPositionFromPresortedList(VpnProfile profile) {
-        TransportType transportType = profile.mUsePluggableTransports ? OBFS4 : OPENVPN;
+        TransportType transportType = profile.getTransportType();
         int nClosest = 0;
         for (Gateway gateway : presortedList) {
             if (gateway.supportsTransport(transportType)) {
@@ -277,9 +285,9 @@ public class GatewaysManager {
         }
         return -1;
     }
-    
+
     private int getPositionFromTimezoneCalculatedList(VpnProfile profile) {
-        TransportType transportType = profile.mUsePluggableTransports ? OBFS4 : OPENVPN;
+        TransportType transportType = profile.getTransportType();
         GatewaySelector gatewaySelector = new GatewaySelector(new ArrayList<>(gateways.values()));
         Gateway gateway;
         int nClosest = 0;
diff --git a/app/src/main/java/se/leap/bitmaskclient/eip/VpnConfigGenerator.java b/app/src/main/java/se/leap/bitmaskclient/eip/VpnConfigGenerator.java
index 5ddb74ab..58732713 100644
--- a/app/src/main/java/se/leap/bitmaskclient/eip/VpnConfigGenerator.java
+++ b/app/src/main/java/se/leap/bitmaskclient/eip/VpnConfigGenerator.java
@@ -16,6 +16,25 @@
  */
 package se.leap.bitmaskclient.eip;
 
+import static de.blinkt.openvpn.core.connection.Connection.TransportType.OBFS4;
+import static de.blinkt.openvpn.core.connection.Connection.TransportType.OBFS4_KCP;
+import static de.blinkt.openvpn.core.connection.Connection.TransportType.OPENVPN;
+import static se.leap.bitmaskclient.base.models.Constants.CAPABILITIES;
+import static se.leap.bitmaskclient.base.models.Constants.IP_ADDRESS;
+import static se.leap.bitmaskclient.base.models.Constants.IP_ADDRESS6;
+import static se.leap.bitmaskclient.base.models.Constants.OPTIONS;
+import static se.leap.bitmaskclient.base.models.Constants.PORTS;
+import static se.leap.bitmaskclient.base.models.Constants.PROTOCOLS;
+import static se.leap.bitmaskclient.base.models.Constants.PROVIDER_PRIVATE_KEY;
+import static se.leap.bitmaskclient.base.models.Constants.PROVIDER_VPN_CERTIFICATE;
+import static se.leap.bitmaskclient.base.models.Constants.REMOTE;
+import static se.leap.bitmaskclient.base.models.Constants.TRANSPORT;
+import static se.leap.bitmaskclient.base.models.Constants.TYPE;
+import static se.leap.bitmaskclient.base.models.Constants.UDP;
+import static se.leap.bitmaskclient.base.utils.ConfigHelper.ObfsVpnHelper.useObfsVpn;
+import static se.leap.bitmaskclient.pluggableTransports.Shapeshifter.DISPATCHER_IP;
+import static se.leap.bitmaskclient.pluggableTransports.Shapeshifter.DISPATCHER_PORT;
+
 import androidx.annotation.VisibleForTesting;
 
 import org.json.JSONArray;
@@ -31,50 +50,36 @@ import de.blinkt.openvpn.VpnProfile;
 import de.blinkt.openvpn.core.ConfigParser;
 import de.blinkt.openvpn.core.VpnStatus;
 import de.blinkt.openvpn.core.connection.Connection;
+import se.leap.bitmaskclient.BuildConfig;
 import se.leap.bitmaskclient.base.models.Provider;
 import se.leap.bitmaskclient.base.utils.ConfigHelper;
 import se.leap.bitmaskclient.pluggableTransports.Obfs4Options;
 
-import static de.blinkt.openvpn.core.connection.Connection.TransportType.OBFS4;
-import static de.blinkt.openvpn.core.connection.Connection.TransportType.OPENVPN;
-import static se.leap.bitmaskclient.base.models.Constants.CAPABILITIES;
-import static se.leap.bitmaskclient.base.models.Constants.IP_ADDRESS;
-import static se.leap.bitmaskclient.base.models.Constants.IP_ADDRESS6;
-import static se.leap.bitmaskclient.base.models.Constants.OPTIONS;
-import static se.leap.bitmaskclient.base.models.Constants.PORTS;
-import static se.leap.bitmaskclient.base.models.Constants.PROTOCOLS;
-import static se.leap.bitmaskclient.base.models.Constants.PROVIDER_PRIVATE_KEY;
-import static se.leap.bitmaskclient.base.models.Constants.PROVIDER_VPN_CERTIFICATE;
-import static se.leap.bitmaskclient.base.models.Constants.REMOTE;
-import static se.leap.bitmaskclient.base.models.Constants.TRANSPORT;
-import static se.leap.bitmaskclient.base.models.Constants.TYPE;
-import static se.leap.bitmaskclient.base.models.Constants.UDP;
-import static se.leap.bitmaskclient.pluggableTransports.Shapeshifter.DISPATCHER_IP;
-import static se.leap.bitmaskclient.pluggableTransports.Shapeshifter.DISPATCHER_PORT;
-
 public class VpnConfigGenerator {
-    private JSONObject generalConfiguration;
-    private JSONObject gateway;
-    private JSONObject secrets;
+    private final JSONObject generalConfiguration;
+    private final JSONObject gateway;
+    private final JSONObject secrets;
     private JSONObject obfs4Transport;
-    private int apiVersion;
-    private boolean preferUDP;
+    private JSONObject obfs4TKcpTransport;
+    private final int apiVersion;
+    private final boolean preferUDP;
+    private final boolean experimentalTransports;
 
 
     public final static String TAG = VpnConfigGenerator.class.getSimpleName();
     private final String newLine = System.getProperty("line.separator"); // Platform new line
 
-    public VpnConfigGenerator(JSONObject generalConfiguration, JSONObject secrets, JSONObject gateway, int apiVersion, boolean preferUDP) throws ConfigParser.ConfigParseError {
+    public VpnConfigGenerator(JSONObject generalConfiguration, JSONObject secrets, JSONObject gateway, int apiVersion, boolean preferUDP, boolean experimentalTransports) throws ConfigParser.ConfigParseError {
         this.generalConfiguration = generalConfiguration;
         this.gateway = gateway;
         this.secrets = secrets;
         this.apiVersion = apiVersion;
         this.preferUDP = preferUDP;
+        this.experimentalTransports = experimentalTransports;
         checkCapabilities();
     }
 
     public void checkCapabilities() throws ConfigParser.ConfigParseError {
-
         try {
             if (apiVersion >= 3) {
                 JSONArray supportedTransports = gateway.getJSONObject(CAPABILITIES).getJSONArray(TRANSPORT);
@@ -82,7 +87,11 @@ public class VpnConfigGenerator {
                     JSONObject transport = supportedTransports.getJSONObject(i);
                     if (transport.getString(TYPE).equals(OBFS4.toString())) {
                         obfs4Transport = transport;
-                        break;
+                        if (!experimentalTransports) {
+                            break;
+                        }
+                    } else if (experimentalTransports && transport.getString(TYPE).equals(OBFS4_KCP.toString())) {
+                        obfs4TKcpTransport = transport;
                     }
                 }
             }
@@ -106,6 +115,13 @@ public class VpnConfigGenerator {
                 e.printStackTrace();
             }
         }
+        if (supportsObfs4Kcp()) {
+            try {
+                profiles.put(OBFS4_KCP, createProfile(OBFS4_KCP));
+            } catch (ConfigParser.ConfigParseError | NumberFormatException | JSONException | IOException e) {
+                e.printStackTrace();
+            }
+        }
         return profiles;
     }
 
@@ -113,6 +129,10 @@ public class VpnConfigGenerator {
         return obfs4Transport != null;
     }
 
+    private boolean supportsObfs4Kcp() {
+        return obfs4TKcpTransport != null;
+    }
+
     private String getConfigurationString(Connection.TransportType transportType) {
         return generalConfiguration()
                 + newLine
@@ -129,18 +149,28 @@ public class VpnConfigGenerator {
         ConfigParser icsOpenvpnConfigParser = new ConfigParser();
         icsOpenvpnConfigParser.parseConfig(new StringReader(configuration));
         if (transportType == OBFS4) {
-            icsOpenvpnConfigParser.setObfs4Options(getObfs4Options());
+            icsOpenvpnConfigParser.setObfs4Options(getObfs4Options(obfs4Transport, false));
+        } else if (transportType == OBFS4_KCP) {
+            icsOpenvpnConfigParser.setObfs4Options(getObfs4Options(obfs4TKcpTransport, true));
         }
         return icsOpenvpnConfigParser.convertProfile(transportType);
     }
 
-    private Obfs4Options getObfs4Options() throws JSONException {
-        JSONObject transportOptions = obfs4Transport.getJSONObject(OPTIONS);
+    private Obfs4Options getObfs4Options(JSONObject transportJson, boolean useUdp) throws JSONException {
+        JSONObject transportOptions = transportJson.getJSONObject(OPTIONS);
         String iatMode = transportOptions.getString("iatMode");
         String cert = transportOptions.getString("cert");
         String port = obfs4Transport.getJSONArray(PORTS).getString(0);
         String ip = gateway.getString(IP_ADDRESS);
-        return new Obfs4Options(ip, port, cert, iatMode);
+        boolean udp = useUdp;
+
+        if (BuildConfig.obfsvpn_pinning) {
+            cert = BuildConfig.obfsvpn_cert;
+            port = BuildConfig.obfsvpn_port;
+            ip = BuildConfig.obfsvpn_port;
+            udp = BuildConfig.obfsvpn_use_kcp;
+        }
+        return new Obfs4Options(ip, port, cert, iatMode, udp);
     }
 
     private String generalConfiguration() {
@@ -321,10 +351,27 @@ public class VpnConfigGenerator {
             return;
         }
 
+        JSONArray ports = obfs4Transport.getJSONArray(PORTS);
+        if (ports.isNull(0)){
+            VpnStatus.logError("Misconfigured provider: no ports defined in obfs4 transport JSON.");
+            return;
+        }
+
         String route = "route " + ipAddress + " 255.255.255.255 net_gateway" + newLine;
         stringBuilder.append(route);
-        String remote = REMOTE + " " + DISPATCHER_IP + " " + DISPATCHER_PORT + " tcp" + newLine;
-        stringBuilder.append(remote);
+        if (useObfsVpn()) {
+            String remote;
+            if (BuildConfig.obfsvpn_pinning) {
+                remote = REMOTE + " " + BuildConfig.obfsvpn_ip + " " + BuildConfig.obfsvpn_port + newLine;
+            } else {
+                remote = REMOTE + " " + ipAddress + " " + ports.getString(0) + newLine;
+            }
+
+            stringBuilder.append(remote);
+        } else {
+            String remote = REMOTE + " " + DISPATCHER_IP + " " + DISPATCHER_PORT + " tcp" + newLine;
+            stringBuilder.append(remote);
+        }
     }
 
     private String secretsConfiguration() {
diff --git a/app/src/main/java/se/leap/bitmaskclient/pluggableTransports/Obfs4Options.java b/app/src/main/java/se/leap/bitmaskclient/pluggableTransports/Obfs4Options.java
index 2f9cb732..b96f88ca 100644
--- a/app/src/main/java/se/leap/bitmaskclient/pluggableTransports/Obfs4Options.java
+++ b/app/src/main/java/se/leap/bitmaskclient/pluggableTransports/Obfs4Options.java
@@ -7,12 +7,15 @@ public class Obfs4Options implements Serializable {
     public String iatMode;
     public String remoteIP;
     public String remotePort;
+    // openvpn is still using tcp, obfs4 is wrapped in kcp, if udp == true
+    public boolean udp;
 
-    public Obfs4Options(String remoteIP, String remotePort, String cert, String iatMode) {
+    public Obfs4Options(String remoteIP, String remotePort, String cert, String iatMode, boolean udp) {
         this.cert = cert;
         this.iatMode = iatMode;
         this.remoteIP = remoteIP;
         this.remotePort = remotePort;
+        this.udp = udp;
     }
 
 }
diff --git a/app/src/main/java/se/leap/bitmaskclient/pluggableTransports/ObfsVpnClient.java b/app/src/main/java/se/leap/bitmaskclient/pluggableTransports/ObfsVpnClient.java
new file mode 100644
index 00000000..f6c8837e
--- /dev/null
+++ b/app/src/main/java/se/leap/bitmaskclient/pluggableTransports/ObfsVpnClient.java
@@ -0,0 +1,127 @@
+package se.leap.bitmaskclient.pluggableTransports;
+
+import android.util.Log;
+
+import java.util.Observable;
+import java.util.Observer;
+import java.util.concurrent.atomic.AtomicBoolean;
+import java.util.concurrent.atomic.AtomicInteger;
+
+import client.Client_;
+import de.blinkt.openvpn.core.ConnectionStatus;
+import de.blinkt.openvpn.core.VpnStatus;
+import se.leap.bitmaskclient.eip.EipStatus;
+
+public class ObfsVpnClient implements Observer, client.EventLogger {
+
+    public static final AtomicInteger SOCKS_PORT = new AtomicInteger(4430);
+    public static final String SOCKS_IP = "127.0.0.1";
+    private static final String ERR_BIND = "bind: address already in use";
+
+    private static final String TAG = ObfsVpnClient.class.getSimpleName();
+    private volatile boolean noNetwork;
+    private final AtomicBoolean pendingNetworkErrorHandling = new AtomicBoolean(false);
+    private final AtomicInteger reconnectRetry = new AtomicInteger(0);
+    private static final int MAX_RETRY = 5;
+
+    private final client.Client_ obfsVpnClient;
+    private final Object LOCK = new Object();
+
+    public ObfsVpnClient(Obfs4Options options) {
+        obfsVpnClient = new Client_(options.udp, SOCKS_IP+":"+SOCKS_PORT.get(), options.cert);
+        obfsVpnClient.setEventLogger(this);
+    }
+
+    /**
+     * starts the client
+     * @return the port ObfsVpn is running on
+     */
+    public int start() {
+        synchronized (LOCK) {
+            Log.d(TAG, "aquired LOCK");
+            new Thread(this::startSync).start();
+            waitUntilStarted();
+            Log.d(TAG, "returning LOCK after " + (reconnectRetry.get() + 1) * 200 +" ms");
+        }
+        return SOCKS_PORT.get();
+    }
+
+    private void waitUntilStarted() {
+        int count = -1;
+        try {
+            while (count < reconnectRetry.get() && reconnectRetry.get() < MAX_RETRY) {
+                Thread.sleep(200);
+                count++;
+            }
+        } catch (InterruptedException e) {
+            e.printStackTrace();
+        }
+    }
+
+    private void startSync() {
+        try {
+            obfsVpnClient.start();
+        } catch (Exception e) {
+            Log.e(TAG, "[obfsvpn] exception: " + e.getLocalizedMessage());
+            VpnStatus.logError("[obfsvpn] " + e.getLocalizedMessage());
+            if (e.getLocalizedMessage() != null && e.getLocalizedMessage().contains(ERR_BIND) && reconnectRetry.get() < MAX_RETRY) {
+                reconnectRetry.addAndGet(1);
+                SOCKS_PORT.addAndGet(1);
+                obfsVpnClient.setSocksAddr(SOCKS_IP+":"+SOCKS_PORT.get());
+                Log.d(TAG, "[obfsvpn] reconnecting on different port... " + SOCKS_PORT.get());
+                VpnStatus.logDebug("[obfsvpn] reconnecting on different port... " + SOCKS_PORT.get());
+                startSync();
+            } else if (noNetwork) {
+                pendingNetworkErrorHandling.set(true);
+            }
+        }
+    }
+
+    public void stop() {
+        synchronized (LOCK) {
+            Log.d(TAG, "stopping obfsVpnClient...");
+            try {
+                obfsVpnClient.stop();
+                reconnectRetry.set(0);
+                SOCKS_PORT.set(4430);
+                Thread.sleep(100);
+            } catch (Exception e) {
+                e.printStackTrace();
+                VpnStatus.logError("[obfsvpn] " + e.getLocalizedMessage());
+            }
+            pendingNetworkErrorHandling.set(false);
+            Log.d(TAG, "stopping obfsVpnClient releasing LOCK ...");
+        }
+    }
+
+    public boolean isStarted() {
+        return obfsVpnClient.isStarted();
+    }
+
+    @Override
+    public void update(Observable observable, Object arg) {
+        if (observable instanceof EipStatus) {
+            EipStatus status = (EipStatus) observable;
+            if (status.getLevel() == ConnectionStatus.LEVEL_NONETWORK) {
+                noNetwork = true;
+            } else {
+                noNetwork = false;
+                if (pendingNetworkErrorHandling.getAndSet(false)) {
+                    stop();
+                    start();
+                }
+            }
+        }
+    }
+
+    @Override
+    public void error(String s) {
+        VpnStatus.logError("[obfsvpn] " + s);
+    }
+
+    @Override
+    public void log(String state, String message) {
+        VpnStatus.logDebug("[obfsvpn] " + state + " " + message);
+    }
+
+}
diff --git a/app/src/main/res/layout/f_settings.xml b/app/src/main/res/layout/f_settings.xml
index 7b8733cd..f89dc956 100644
--- a/app/src/main/res/layout/f_settings.xml
+++ b/app/src/main/res/layout/f_settings.xml
@@ -114,5 +114,14 @@
             app:subtitle="Connect to a specific Gateway for debugging purposes"
             />
 
+        <se.leap.bitmaskclient.base.views.IconSwitchEntry
+            android:id="@+id/experimental_transports"
+            android:layout_width="match_parent"
+            android:layout_height="wrap_content"
+            app:text="Experimental transports"
+            app:singleLine="false"
+            app:subtitle="These transports might circumvent censorship, but are still in a testing phase"
+            />
+
     </LinearLayout>
 </ScrollView>
\ No newline at end of file