Migrate tunnel related classes to tunnel/ Gradle module

Signed-off-by: Harsh Shandilya <me@msfjarvis.dev>

25 files changed, 0 insertions, 3493 deletions

diff --git a/app/src/main/AndroidManifest.xml b/app/src/main/AndroidManifest.xml
index 4bcb7588..5e993ae2 100644
--- a/app/src/main/AndroidManifest.xml
+++ b/app/src/main/AndroidManifest.xml
@@ -74,14 +74,6 @@
         </receiver>
 
         <service
-            android:name=".backend.GoBackend$VpnService"
-            android:permission="android.permission.BIND_VPN_SERVICE">
-            <intent-filter>
-                <action android:name="android.net.VpnService" />
-            </intent-filter>
-        </service>
-
-        <service
             android:name=".QuickTileService"
             android:icon="@drawable/ic_tile"
             android:permission="android.permission.BIND_QUICK_SETTINGS_TILE">
diff --git a/app/src/main/java/com/wireguard/android/backend/Backend.java b/app/src/main/java/com/wireguard/android/backend/Backend.java
deleted file mode 100644
index ed3a5ebd..00000000
--- a/app/src/main/java/com/wireguard/android/backend/Backend.java
+++ /dev/null
@@ -1,63 +0,0 @@
-/*
- * Copyright © 2017-2019 WireGuard LLC. All Rights Reserved.
- * SPDX-License-Identifier: Apache-2.0
- */
-
-package com.wireguard.android.backend;
-
-import com.wireguard.config.Config;
-
-import java.util.Collection;
-import java.util.Set;
-
-import androidx.annotation.Nullable;
-
-/**
- * Interface for implementations of the WireGuard secure network tunnel.
- */
-
-public interface Backend {
-    /**
-     * Enumerate names of currently-running tunnels.
-     *
-     * @return The set of running tunnel names.
-     */
-    Set<String> getRunningTunnelNames();
-
-    /**
-     * Get the state of a tunnel.
-     *
-     * @param tunnel The tunnel to examine the state of.
-     * @return The state of the tunnel.
-     */
-    Tunnel.State getState(Tunnel tunnel) throws Exception;
-
-    /**
-     * Get statistics about traffic and errors on this tunnel. If the tunnel is not running, the
-     * statistics object will be filled with zero values.
-     *
-     * @param tunnel The tunnel to retrieve statistics for.
-     * @return The statistics for the tunnel.
-     */
-    Statistics getStatistics(Tunnel tunnel) throws Exception;
-
-    /**
-     * Determine version of underlying backend.
-     *
-     * @return The version of the backend.
-     * @throws Exception
-     */
-    String getVersion() throws Exception;
-
-    /**
-     * Set the state of a tunnel, updating it's configuration. If the tunnel is already up, config
-     * may update the running configuration; config may be null when setting the tunnel down.
-     *
-     * @param tunnel The tunnel to control the state of.
-     * @param state  The new state for this tunnel. Must be {@code UP}, {@code DOWN}, or
-     *               {@code TOGGLE}.
-     * @param config The configuration for this tunnel, may be null if state is {@code DOWN}.
-     * @return The updated state of the tunnel.
-     */
-    Tunnel.State setState(Tunnel tunnel, Tunnel.State state, @Nullable Config config) throws Exception;
-}
diff --git a/app/src/main/java/com/wireguard/android/backend/BackendException.java b/app/src/main/java/com/wireguard/android/backend/BackendException.java
deleted file mode 100644
index e1e8eaa9..00000000
--- a/app/src/main/java/com/wireguard/android/backend/BackendException.java
+++ /dev/null
@@ -1,30 +0,0 @@
-/*
- * Copyright © 2020 WireGuard LLC. All Rights Reserved.
- * SPDX-License-Identifier: Apache-2.0
- */
-
-package com.wireguard.android.backend;
-
-public final class BackendException extends Exception {
-    public enum Reason {
-        UNKNOWN_KERNEL_MODULE_NAME,
-        WG_QUICK_CONFIG_ERROR_CODE,
-        TUNNEL_MISSING_CONFIG,
-        VPN_NOT_AUTHORIZED,
-        UNABLE_TO_START_VPN,
-        TUN_CREATION_ERROR,
-        GO_ACTIVATION_ERROR_CODE
-    }
-    private final Reason reason;
-    private final Object[] format;
-    public BackendException(final Reason reason, final Object ...format) {
-        this.reason = reason;
-        this.format = format;
-    }
-    public Reason getReason() {
-        return reason;
-    }
-    public Object[] getFormat() {
-        return format;
-    }
-}
diff --git a/app/src/main/java/com/wireguard/android/backend/GoBackend.java b/app/src/main/java/com/wireguard/android/backend/GoBackend.java
deleted file mode 100644
index 6ad5afa4..00000000
--- a/app/src/main/java/com/wireguard/android/backend/GoBackend.java
+++ /dev/null
@@ -1,292 +0,0 @@
-/*
- * Copyright © 2017-2019 WireGuard LLC. All Rights Reserved.
- * SPDX-License-Identifier: Apache-2.0
- */
-
-package com.wireguard.android.backend;
-
-import android.content.Context;
-import android.content.Intent;
-import android.os.Build;
-import android.os.ParcelFileDescriptor;
-import androidx.annotation.Nullable;
-import androidx.collection.ArraySet;
-import android.util.Log;
-
-import com.wireguard.android.backend.BackendException.Reason;
-import com.wireguard.android.backend.Tunnel.State;
-import com.wireguard.android.util.SharedLibraryLoader;
-import com.wireguard.config.Config;
-import com.wireguard.config.InetNetwork;
-import com.wireguard.config.Peer;
-import com.wireguard.crypto.Key;
-import com.wireguard.crypto.KeyFormatException;
-
-import java.net.InetAddress;
-import java.util.Collections;
-import java.util.Set;
-import java.util.concurrent.TimeUnit;
-import java.util.concurrent.TimeoutException;
-
-import java9.util.concurrent.CompletableFuture;
-
-public final class GoBackend implements Backend {
-    private static final String TAG = "WireGuard/" + GoBackend.class.getSimpleName();
-    private static CompletableFuture<VpnService> vpnService = new CompletableFuture<>();
-    public interface AlwaysOnCallback {
-        void alwaysOnTriggered();
-    }
-    @Nullable private static AlwaysOnCallback alwaysOnCallback;
-    public static void setAlwaysOnCallback(AlwaysOnCallback cb) {
-        alwaysOnCallback = cb;
-    }
-
-    private final Context context;
-    @Nullable private Tunnel currentTunnel;
-    @Nullable private Config currentConfig;
-    private int currentTunnelHandle = -1;
-
-    public GoBackend(final Context context) {
-        SharedLibraryLoader.loadSharedLibrary(context, "wg-go");
-        this.context = context;
-    }
-
-    private static native String wgGetConfig(int handle);
-
-    private static native int wgGetSocketV4(int handle);
-
-    private static native int wgGetSocketV6(int handle);
-
-    private static native void wgTurnOff(int handle);
-
-    private static native int wgTurnOn(String ifName, int tunFd, String settings);
-
-    private static native String wgVersion();
-
-    @Override
-    public Set<String> getRunningTunnelNames() {
-        if (currentTunnel != null) {
-            final Set<String> runningTunnels = new ArraySet<>();
-            runningTunnels.add(currentTunnel.getName());
-            return runningTunnels;
-        }
-        return Collections.emptySet();
-    }
-
-    @Override
-    public State getState(final Tunnel tunnel) {
-        return currentTunnel == tunnel ? State.UP : State.DOWN;
-    }
-
-    @Override
-    public Statistics getStatistics(final Tunnel tunnel) {
-        final Statistics stats = new Statistics();
-        if (tunnel != currentTunnel) {
-            return stats;
-        }
-        final String config = wgGetConfig(currentTunnelHandle);
-        Key key = null;
-        long rx = 0, tx = 0;
-        for (final String line : config.split("\\n")) {
-            if (line.startsWith("public_key=")) {
-                if (key != null)
-                    stats.add(key, rx, tx);
-                rx = 0;
-                tx = 0;
-                try {
-                    key = Key.fromHex(line.substring(11));
-                } catch (final KeyFormatException ignored) {
-                    key = null;
-                }
-            } else if (line.startsWith("rx_bytes=")) {
-                if (key == null)
-                    continue;
-                try {
-                    rx = Long.parseLong(line.substring(9));
-                } catch (final NumberFormatException ignored) {
-                    rx = 0;
-                }
-            } else if (line.startsWith("tx_bytes=")) {
-                if (key == null)
-                    continue;
-                try {
-                    tx = Long.parseLong(line.substring(9));
-                } catch (final NumberFormatException ignored) {
-                    tx = 0;
-                }
-            }
-        }
-        if (key != null)
-            stats.add(key, rx, tx);
-        return stats;
-    }
-
-    @Override
-    public String getVersion() {
-        return wgVersion();
-    }
-
-    @Override
-    public State setState(final Tunnel tunnel, State state, @Nullable final Config config) throws Exception {
-        final State originalState = getState(tunnel);
-
-        if (state == State.TOGGLE)
-            state = originalState == State.UP ? State.DOWN : State.UP;
-        if (state == originalState && tunnel == currentTunnel && config == currentConfig)
-            return originalState;
-        if (state == State.UP) {
-            final Config originalConfig = currentConfig;
-            final Tunnel originalTunnel = currentTunnel;
-            if (currentTunnel != null)
-                setStateInternal(currentTunnel, null, State.DOWN);
-            try {
-                setStateInternal(tunnel, config, state);
-            } catch(final Exception e) {
-                if (originalTunnel != null)
-                    setStateInternal(originalTunnel, originalConfig, State.UP);
-                throw e;
-            }
-        } else if (state == State.DOWN && tunnel == currentTunnel) {
-            setStateInternal(tunnel, null, State.DOWN);
-        }
-        return getState(tunnel);
-    }
-
-    private void setStateInternal(final Tunnel tunnel, @Nullable final Config config, final State state)
-            throws Exception {
-        Log.i(TAG, "Bringing tunnel " + tunnel.getName() + " " + state);
-
-        if (state == State.UP) {
-            if (config == null)
-                throw new BackendException(Reason.TUNNEL_MISSING_CONFIG);
-
-            if (VpnService.prepare(context) != null)
-                throw new BackendException(Reason.VPN_NOT_AUTHORIZED);
-
-            final VpnService service;
-            if (!vpnService.isDone())
-                startVpnService();
-
-            try {
-                service = vpnService.get(2, TimeUnit.SECONDS);
-            } catch (final TimeoutException e) {
-                final Exception be = new BackendException(Reason.UNABLE_TO_START_VPN);
-                be.initCause(e);
-                throw be;
-            }
-            service.setOwner(this);
-
-            if (currentTunnelHandle != -1) {
-                Log.w(TAG, "Tunnel already up");
-                return;
-            }
-
-            // Build config
-            final String goConfig = config.toWgUserspaceString();
-
-            // Create the vpn tunnel with android API
-            final VpnService.Builder builder = service.getBuilder();
-            builder.setSession(tunnel.getName());
-
-            for (final String excludedApplication : config.getInterface().getExcludedApplications())
-                builder.addDisallowedApplication(excludedApplication);
-
-            for (final InetNetwork addr : config.getInterface().getAddresses())
-                builder.addAddress(addr.getAddress(), addr.getMask());
-
-            for (final InetAddress addr : config.getInterface().getDnsServers())
-                builder.addDnsServer(addr.getHostAddress());
-
-            for (final Peer peer : config.getPeers()) {
-                for (final InetNetwork addr : peer.getAllowedIps())
-                    builder.addRoute(addr.getAddress(), addr.getMask());
-            }
-
-            builder.setMtu(config.getInterface().getMtu().orElse(1280));
-
-            if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.Q)
-                builder.setMetered(false);
-            if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M)
-	        service.setUnderlyingNetworks(null);
-
-            builder.setBlocking(true);
-            try (final ParcelFileDescriptor tun = builder.establish()) {
-                if (tun == null)
-                    throw new BackendException(Reason.TUN_CREATION_ERROR);
-                Log.d(TAG, "Go backend v" + wgVersion());
-                currentTunnelHandle = wgTurnOn(tunnel.getName(), tun.detachFd(), goConfig);
-            }
-            if (currentTunnelHandle < 0)
-                throw new BackendException(Reason.GO_ACTIVATION_ERROR_CODE, currentTunnelHandle);
-
-            currentTunnel = tunnel;
-            currentConfig = config;
-
-            service.protect(wgGetSocketV4(currentTunnelHandle));
-            service.protect(wgGetSocketV6(currentTunnelHandle));
-        } else {
-            if (currentTunnelHandle == -1) {
-                Log.w(TAG, "Tunnel already down");
-                return;
-            }
-
-            wgTurnOff(currentTunnelHandle);
-            currentTunnel = null;
-            currentTunnelHandle = -1;
-            currentConfig = null;
-        }
-
-        tunnel.onStateChange(state);
-    }
-
-    private void startVpnService() {
-        Log.d(TAG, "Requesting to start VpnService");
-        context.startService(new Intent(context, VpnService.class));
-    }
-
-    public static class VpnService extends android.net.VpnService {
-        @Nullable private GoBackend owner;
-
-        public void setOwner(final GoBackend owner) {
-            this.owner = owner;
-        }
-
-        public Builder getBuilder() {
-            return new Builder();
-        }
-
-        @Override
-        public void onCreate() {
-            vpnService.complete(this);
-            super.onCreate();
-        }
-
-        @Override
-        public void onDestroy() {
-            if (owner != null) {
-                final Tunnel tunnel = owner.currentTunnel;
-                if (tunnel != null) {
-                    if (owner.currentTunnelHandle != -1)
-                        wgTurnOff(owner.currentTunnelHandle);
-                    owner.currentTunnel = null;
-                    owner.currentTunnelHandle = -1;
-                    owner.currentConfig = null;
-                    tunnel.onStateChange(State.DOWN);
-                }
-            }
-            vpnService = vpnService.newIncompleteFuture();
-            super.onDestroy();
-        }
-
-        @Override
-        public int onStartCommand(@Nullable final Intent intent, final int flags, final int startId) {
-            vpnService.complete(this);
-            if (intent == null || intent.getComponent() == null || !intent.getComponent().getPackageName().equals(getPackageName())) {
-                Log.d(TAG, "Service started by Always-on VPN feature");
-                if (alwaysOnCallback != null)
-                    alwaysOnCallback.alwaysOnTriggered();
-            }
-            return super.onStartCommand(intent, flags, startId);
-        }
-    }
-}
diff --git a/app/src/main/java/com/wireguard/android/backend/Statistics.java b/app/src/main/java/com/wireguard/android/backend/Statistics.java
deleted file mode 100644
index 2ca87d23..00000000
--- a/app/src/main/java/com/wireguard/android/backend/Statistics.java
+++ /dev/null
@@ -1,62 +0,0 @@
-/*
- * Copyright © 2020 WireGuard LLC. All Rights Reserved.
- * SPDX-License-Identifier: Apache-2.0
- */
-
-package com.wireguard.android.backend;
-
-import android.os.SystemClock;
-import android.util.Pair;
-
-import com.wireguard.crypto.Key;
-
-import java.util.HashMap;
-import java.util.Map;
-
-public class Statistics {
-    private long lastTouched = SystemClock.elapsedRealtime();
-    private final Map<Key, Pair<Long, Long>> peerBytes = new HashMap<>();
-
-    Statistics() { }
-
-    void add(final Key key, final long rx, final long tx) {
-        peerBytes.put(key, Pair.create(rx, tx));
-        lastTouched = SystemClock.elapsedRealtime();
-    }
-
-    public boolean isStale() {
-        return SystemClock.elapsedRealtime() - lastTouched > 900;
-    }
-
-    public Key[] peers() {
-        return peerBytes.keySet().toArray(new Key[0]);
-    }
-
-    public long peerRx(final Key peer) {
-        if (!peerBytes.containsKey(peer))
-            return 0;
-        return peerBytes.get(peer).first;
-    }
-
-    public long peerTx(final Key peer) {
-        if (!peerBytes.containsKey(peer))
-            return 0;
-        return peerBytes.get(peer).second;
-    }
-
-    public long totalRx() {
-        long rx = 0;
-        for (final Pair<Long, Long> val : peerBytes.values()) {
-            rx += val.first;
-        }
-        return rx;
-    }
-
-    public long totalTx() {
-        long tx = 0;
-        for (final Pair<Long, Long> val : peerBytes.values()) {
-            tx += val.second;
-        }
-        return tx;
-    }
-}
diff --git a/app/src/main/java/com/wireguard/android/backend/Tunnel.java b/app/src/main/java/com/wireguard/android/backend/Tunnel.java
deleted file mode 100644
index af2f59f7..00000000
--- a/app/src/main/java/com/wireguard/android/backend/Tunnel.java
+++ /dev/null
@@ -1,46 +0,0 @@
-/*
- * Copyright © 2020 WireGuard LLC. All Rights Reserved.
- * SPDX-License-Identifier: Apache-2.0
- */
-
-package com.wireguard.android.backend;
-
-import java.util.regex.Pattern;
-
-/**
- * Represents a WireGuard tunnel.
- */
-
-public interface Tunnel {
-    enum State {
-        DOWN,
-        TOGGLE,
-        UP;
-
-        public static State of(final boolean running) {
-            return running ? UP : DOWN;
-        }
-    }
-
-    int NAME_MAX_LENGTH = 15;
-    Pattern NAME_PATTERN = Pattern.compile("[a-zA-Z0-9_=+.-]{1,15}");
-
-    static boolean isNameInvalid(final CharSequence name) {
-        return !NAME_PATTERN.matcher(name).matches();
-    }
-
-    /**
-     * Get the name of the tunnel, which should always pass the !isNameInvalid test.
-     *
-     * @return The name of the tunnel.
-     */
-    String getName();
-
-    /**
-     * React to a change in state of the tunnel. Should only be directly called by Backend.
-     *
-     * @param newState The new state of the tunnel.
-     * @return The new state of the tunnel.
-     */
-    void onStateChange(State newState);
-}
diff --git a/app/src/main/java/com/wireguard/android/backend/WgQuickBackend.java b/app/src/main/java/com/wireguard/android/backend/WgQuickBackend.java
deleted file mode 100644
index 9695aab7..00000000
--- a/app/src/main/java/com/wireguard/android/backend/WgQuickBackend.java
+++ /dev/null
@@ -1,158 +0,0 @@
-/*
- * Copyright © 2017-2019 WireGuard LLC. All Rights Reserved.
- * SPDX-License-Identifier: Apache-2.0
- */
-
-package com.wireguard.android.backend;
-
-import androidx.annotation.Nullable;
-
-import android.content.Context;
-import android.util.Log;
-
-import com.wireguard.android.backend.BackendException.Reason;
-import com.wireguard.android.backend.Tunnel.State;
-import com.wireguard.android.util.RootShell;
-import com.wireguard.android.util.ToolsInstaller;
-import com.wireguard.config.Config;
-import com.wireguard.crypto.Key;
-
-import java.io.File;
-import java.io.FileOutputStream;
-import java.nio.charset.StandardCharsets;
-import java.util.ArrayList;
-import java.util.Collection;
-import java.util.Collections;
-import java.util.List;
-import java.util.Locale;
-import java.util.Map;
-import java.util.Objects;
-import java.util.Set;
-import java.util.HashMap;
-
-import java9.util.stream.Collectors;
-import java9.util.stream.Stream;
-
-/**
- * WireGuard backend that uses {@code wg-quick} to implement tunnel configuration.
- */
-
-public final class WgQuickBackend implements Backend {
-    private static final String TAG = "WireGuard/" + WgQuickBackend.class.getSimpleName();
-
-    private final RootShell rootShell;
-    private final ToolsInstaller toolsInstaller;
-    private final File localTemporaryDir;
-    private final Map<Tunnel, Config> runningConfigs = new HashMap<>();
-
-    public WgQuickBackend(final Context context, final RootShell rootShell, final ToolsInstaller toolsInstaller) {
-        localTemporaryDir = new File(context.getCacheDir(), "tmp");
-        this.rootShell = rootShell;
-        this.toolsInstaller = toolsInstaller;
-    }
-
-    @Override
-    public Set<String> getRunningTunnelNames() {
-        final List<String> output = new ArrayList<>();
-        // Don't throw an exception here or nothing will show up in the UI.
-        try {
-            toolsInstaller.ensureToolsAvailable();
-            if (rootShell.run(output, "wg show interfaces") != 0 || output.isEmpty())
-                return Collections.emptySet();
-        } catch (final Exception e) {
-            Log.w(TAG, "Unable to enumerate running tunnels", e);
-            return Collections.emptySet();
-        }
-        // wg puts all interface names on the same line. Split them into separate elements.
-        return Stream.of(output.get(0).split(" ")).collect(Collectors.toUnmodifiableSet());
-    }
-
-    @Override
-    public State getState(final Tunnel tunnel) {
-        return getRunningTunnelNames().contains(tunnel.getName()) ? State.UP : State.DOWN;
-    }
-
-    @Override
-    public Statistics getStatistics(final Tunnel tunnel) {
-        final Statistics stats = new Statistics();
-        final Collection<String> output = new ArrayList<>();
-        try {
-            if (rootShell.run(output, String.format("wg show '%s' transfer", tunnel.getName())) != 0)
-                return stats;
-        } catch (final Exception ignored) {
-            return stats;
-        }
-        for (final String line : output) {
-            final String[] parts = line.split("\\t");
-            if (parts.length != 3)
-                continue;
-            try {
-                stats.add(Key.fromBase64(parts[0]), Long.parseLong(parts[1]), Long.parseLong(parts[2]));
-            } catch (final Exception ignored) {
-            }
-        }
-        return stats;
-    }
-
-    @Override
-    public String getVersion() throws Exception {
-        final List<String> output = new ArrayList<>();
-        if (rootShell.run(output, "cat /sys/module/wireguard/version") != 0 || output.isEmpty())
-            throw new BackendException(Reason.UNKNOWN_KERNEL_MODULE_NAME);
-        return output.get(0);
-    }
-
-    @Override
-    public State setState(final Tunnel tunnel, State state, @Nullable final Config config) throws Exception {
-        final State originalState = getState(tunnel);
-        final Config originalConfig = runningConfigs.get(tunnel);
-
-        if (state == State.TOGGLE)
-            state = originalState == State.UP ? State.DOWN : State.UP;
-        if ((state == State.UP && originalState == State.UP && originalConfig != null && originalConfig == config) ||
-                (state == State.DOWN && originalState == State.DOWN))
-            return originalState;
-        if (state == State.UP) {
-            toolsInstaller.ensureToolsAvailable();
-            if (originalState == State.UP)
-                setStateInternal(tunnel, originalConfig == null ? config : originalConfig, State.DOWN);
-            try {
-                setStateInternal(tunnel, config, State.UP);
-            } catch(final Exception e) {
-                if (originalState == State.UP && originalConfig != null)
-                    setStateInternal(tunnel, originalConfig, State.UP);
-                throw e;
-            }
-        } else if (state == State.DOWN) {
-            setStateInternal(tunnel, originalConfig == null ? config : originalConfig, State.DOWN);
-        }
-        return state;
-    }
-
-    private void setStateInternal(final Tunnel tunnel, @Nullable final Config config, final State state) throws Exception {
-        Log.i(TAG, "Bringing tunnel " + tunnel.getName() + " " + state);
-
-        Objects.requireNonNull(config, "Trying to set state up with a null config");
-
-        final File tempFile = new File(localTemporaryDir, tunnel.getName() + ".conf");
-        try (final FileOutputStream stream = new FileOutputStream(tempFile, false)) {
-            stream.write(config.toWgQuickString().getBytes(StandardCharsets.UTF_8));
-        }
-        String command = String.format("wg-quick %s '%s'",
-                state.toString().toLowerCase(Locale.ENGLISH), tempFile.getAbsolutePath());
-        if (state == State.UP)
-            command = "cat /sys/module/wireguard/version && " + command;
-        final int result = rootShell.run(null, command);
-        // noinspection ResultOfMethodCallIgnored
-        tempFile.delete();
-        if (result != 0)
-            throw new BackendException(Reason.WG_QUICK_CONFIG_ERROR_CODE, result);
-
-        if (state == State.UP)
-            runningConfigs.put(tunnel, config);
-        else
-            runningConfigs.remove(tunnel);
-
-        tunnel.onStateChange(state);
-    }
-}
diff --git a/app/src/main/java/com/wireguard/android/util/AsyncWorker.java b/app/src/main/java/com/wireguard/android/util/AsyncWorker.java
deleted file mode 100644
index 1d041851..00000000
--- a/app/src/main/java/com/wireguard/android/util/AsyncWorker.java
+++ /dev/null
@@ -1,63 +0,0 @@
-/*
- * Copyright © 2017-2019 WireGuard LLC. All Rights Reserved.
- * SPDX-License-Identifier: Apache-2.0
- */
-
-package com.wireguard.android.util;
-
-import android.os.Handler;
-
-import java.util.concurrent.Executor;
-
-import java9.util.concurrent.CompletableFuture;
-import java9.util.concurrent.CompletionStage;
-
-/**
- * Helper class for running asynchronous tasks and ensuring they are completed on the main thread.
- */
-
-public class AsyncWorker {
-    private final Executor executor;
-    private final Handler handler;
-
-    public AsyncWorker(final Executor executor, final Handler handler) {
-        this.executor = executor;
-        this.handler = handler;
-    }
-
-    public CompletionStage<Void> runAsync(final AsyncRunnable<?> runnable) {
-        final CompletableFuture<Void> future = new CompletableFuture<>();
-        executor.execute(() -> {
-            try {
-                runnable.run();
-                handler.post(() -> future.complete(null));
-            } catch (final Throwable t) {
-                handler.post(() -> future.completeExceptionally(t));
-            }
-        });
-        return future;
-    }
-
-    public <T> CompletionStage<T> supplyAsync(final AsyncSupplier<T, ?> supplier) {
-        final CompletableFuture<T> future = new CompletableFuture<>();
-        executor.execute(() -> {
-            try {
-                final T result = supplier.get();
-                handler.post(() -> future.complete(result));
-            } catch (final Throwable t) {
-                handler.post(() -> future.completeExceptionally(t));
-            }
-        });
-        return future;
-    }
-
-    @FunctionalInterface
-    public interface AsyncRunnable<E extends Throwable> {
-        void run() throws E;
-    }
-
-    @FunctionalInterface
-    public interface AsyncSupplier<T, E extends Throwable> {
-        T get() throws E;
-    }
-}
diff --git a/app/src/main/java/com/wireguard/android/util/RootShell.java b/app/src/main/java/com/wireguard/android/util/RootShell.java
deleted file mode 100644
index 1fc2c9f2..00000000
--- a/app/src/main/java/com/wireguard/android/util/RootShell.java
+++ /dev/null
@@ -1,211 +0,0 @@
-/*
- * Copyright © 2017-2019 WireGuard LLC. All Rights Reserved.
- * SPDX-License-Identifier: Apache-2.0
- */
-
-package com.wireguard.android.util;
-
-import android.content.Context;
-import androidx.annotation.Nullable;
-import android.util.Log;
-
-import com.wireguard.android.util.RootShell.RootShellException.Reason;
-
-import java.io.BufferedReader;
-import java.io.File;
-import java.io.IOException;
-import java.io.InputStreamReader;
-import java.io.OutputStreamWriter;
-import java.nio.charset.StandardCharsets;
-import java.util.Collection;
-import java.util.UUID;
-
-/**
- * Helper class for running commands as root.
- */
-
-public class RootShell {
-    private static final String SU = "su";
-    private static final String TAG = "WireGuard/" + RootShell.class.getSimpleName();
-
-    private final File localBinaryDir;
-    private final File localTemporaryDir;
-    private final Object lock = new Object();
-    private final String preamble;
-    @Nullable private Process process;
-    @Nullable private BufferedReader stderr;
-    @Nullable private OutputStreamWriter stdin;
-    @Nullable private BufferedReader stdout;
-
-    public RootShell(final Context context) {
-        localBinaryDir = new File(context.getCodeCacheDir(), "bin");
-        localTemporaryDir = new File(context.getCacheDir(), "tmp");
-        preamble = String.format("export CALLING_PACKAGE=%s PATH=\"%s:$PATH\" TMPDIR='%s'; id -u\n",
-                context.getPackageName(), localBinaryDir, localTemporaryDir);
-    }
-
-    private static boolean isExecutableInPath(final String name) {
-        final String path = System.getenv("PATH");
-        if (path == null)
-            return false;
-        for (final String dir : path.split(":"))
-            if (new File(dir, name).canExecute())
-                return true;
-        return false;
-    }
-
-    private boolean isRunning() {
-        synchronized (lock) {
-            try {
-                // Throws an exception if the process hasn't finished yet.
-                if (process != null)
-                    process.exitValue();
-                return false;
-            } catch (final IllegalThreadStateException ignored) {
-                // The existing process is still running.
-                return true;
-            }
-        }
-    }
-
-    /**
-     * Run a command in a root shell.
-     *
-     * @param output  Lines read from stdout are appended to this list. Pass null if the
-     *                output from the shell is not important.
-     * @param command Command to run as root.
-     * @return The exit value of the command.
-     */
-    public int run(@Nullable final Collection<String> output, final String command)
-            throws IOException, RootShellException {
-        synchronized (lock) {
-            /* Start inside synchronized block to prevent a concurrent call to stop(). */
-            start();
-            final String marker = UUID.randomUUID().toString();
-            final String script = "echo " + marker + "; echo " + marker + " >&2; (" + command +
-                    "); ret=$?; echo " + marker + " $ret; echo " + marker + " $ret >&2\n";
-            Log.v(TAG, "executing: " + command);
-            stdin.write(script);
-            stdin.flush();
-            String line;
-            int errnoStdout = Integer.MIN_VALUE;
-            int errnoStderr = Integer.MAX_VALUE;
-            int markersSeen = 0;
-            while ((line = stdout.readLine()) != null) {
-                if (line.startsWith(marker)) {
-                    ++markersSeen;
-                    if (line.length() > marker.length() + 1) {
-                        errnoStdout = Integer.valueOf(line.substring(marker.length() + 1));
-                        break;
-                    }
-                } else if (markersSeen > 0) {
-                    if (output != null)
-                        output.add(line);
-                    Log.v(TAG, "stdout: " + line);
-                }
-            }
-            while ((line = stderr.readLine()) != null) {
-                if (line.startsWith(marker)) {
-                    ++markersSeen;
-                    if (line.length() > marker.length() + 1) {
-                        errnoStderr = Integer.valueOf(line.substring(marker.length() + 1));
-                        break;
-                    }
-                } else if (markersSeen > 2) {
-                    Log.v(TAG, "stderr: " + line);
-                }
-            }
-            if (markersSeen != 4)
-                throw new RootShellException(Reason.SHELL_MARKER_COUNT_ERROR, markersSeen);
-            if (errnoStdout != errnoStderr)
-                throw new RootShellException(Reason.SHELL_EXIT_STATUS_READ_ERROR);
-            Log.v(TAG, "exit: " + errnoStdout);
-            return errnoStdout;
-        }
-    }
-
-    public void start() throws IOException, RootShellException {
-        if (!isExecutableInPath(SU))
-            throw new RootShellException(Reason.NO_ROOT_ACCESS);
-        synchronized (lock) {
-            if (isRunning())
-                return;
-            if (!localBinaryDir.isDirectory() && !localBinaryDir.mkdirs())
-                throw new RootShellException(Reason.CREATE_BIN_DIR_ERROR);
-            if (!localTemporaryDir.isDirectory() && !localTemporaryDir.mkdirs())
-                throw new RootShellException(Reason.CREATE_TEMP_DIR_ERROR);
-            try {
-                final ProcessBuilder builder = new ProcessBuilder().command(SU);
-                builder.environment().put("LC_ALL", "C");
-                try {
-                    process = builder.start();
-                } catch (final IOException e) {
-                    // A failure at this stage means the device isn't rooted.
-                    final RootShellException rse = new RootShellException(Reason.NO_ROOT_ACCESS);
-                    rse.initCause(e);
-                    throw rse;
-                }
-                stdin = new OutputStreamWriter(process.getOutputStream(), StandardCharsets.UTF_8);
-                stdout = new BufferedReader(new InputStreamReader(process.getInputStream(),
-                        StandardCharsets.UTF_8));
-                stderr = new BufferedReader(new InputStreamReader(process.getErrorStream(),
-                        StandardCharsets.UTF_8));
-                stdin.write(preamble);
-                stdin.flush();
-                // Check that the shell started successfully.
-                final String uid = stdout.readLine();
-                if (!"0".equals(uid)) {
-                    Log.w(TAG, "Root check did not return correct UID: " + uid);
-                    throw new RootShellException(Reason.NO_ROOT_ACCESS);
-                }
-                if (!isRunning()) {
-                    String line;
-                    while ((line = stderr.readLine()) != null) {
-                        Log.w(TAG, "Root check returned an error: " + line);
-                        if (line.contains("Permission denied"))
-                            throw new RootShellException(Reason.NO_ROOT_ACCESS);
-                    }
-                    throw new RootShellException(Reason.SHELL_START_ERROR, process.exitValue());
-                }
-            } catch (final IOException | RootShellException e) {
-                stop();
-                throw e;
-            }
-        }
-    }
-
-    public void stop() {
-        synchronized (lock) {
-            if (process != null) {
-                process.destroy();
-                process = null;
-            }
-        }
-    }
-
-    public static class RootShellException extends Exception {
-        public enum Reason {
-            NO_ROOT_ACCESS,
-            SHELL_MARKER_COUNT_ERROR,
-            SHELL_EXIT_STATUS_READ_ERROR,
-            SHELL_START_ERROR,
-            CREATE_BIN_DIR_ERROR,
-            CREATE_TEMP_DIR_ERROR
-        }
-        private final Reason reason;
-        private final Object[] format;
-        public RootShellException(final Reason reason, final Object ...format) {
-            this.reason = reason;
-            this.format = format;
-        }
-        public boolean isIORelated() {
-            return reason != Reason.NO_ROOT_ACCESS;
-        }
-        public Reason getReason() {
-            return reason;
-        }
-        public Object[] getFormat() {
-            return format;
-        }
-    }
-}
diff --git a/app/src/main/java/com/wireguard/android/util/SharedLibraryLoader.java b/app/src/main/java/com/wireguard/android/util/SharedLibraryLoader.java
deleted file mode 100644
index 93e44b64..00000000
--- a/app/src/main/java/com/wireguard/android/util/SharedLibraryLoader.java
+++ /dev/null
@@ -1,94 +0,0 @@
-/*
- * Copyright © 2017-2019 WireGuard LLC. All Rights Reserved.
- * SPDX-License-Identifier: Apache-2.0
- */
-
-package com.wireguard.android.util;
-
-import android.content.Context;
-import android.os.Build;
-import android.util.Log;
-
-import java.io.File;
-import java.io.FileOutputStream;
-import java.io.IOException;
-import java.io.InputStream;
-import java.util.Arrays;
-import java.util.Collection;
-import java.util.HashSet;
-import java.util.zip.ZipEntry;
-import java.util.zip.ZipFile;
-
-public final class SharedLibraryLoader {
-    private static final String TAG = "WireGuard/" + SharedLibraryLoader.class.getSimpleName();
-
-    private SharedLibraryLoader() {
-    }
-
-    public static boolean extractLibrary(final Context context, final String libName, final File destination) throws IOException {
-        final Collection<String> apks = new HashSet<>();
-        if (context.getApplicationInfo().sourceDir != null)
-            apks.add(context.getApplicationInfo().sourceDir);
-        if (context.getApplicationInfo().splitSourceDirs != null)
-            apks.addAll(Arrays.asList(context.getApplicationInfo().splitSourceDirs));
-
-        for (final String abi : Build.SUPPORTED_ABIS) {
-            for (final String apk : apks) {
-                final ZipFile zipFile;
-                try {
-                    zipFile = new ZipFile(new File(apk), ZipFile.OPEN_READ);
-                } catch (final IOException e) {
-                    throw new RuntimeException(e);
-                }
-
-                final String mappedLibName = System.mapLibraryName(libName);
-                final byte[] buffer = new byte[1024 * 32];
-                final String libZipPath = "lib" + File.separatorChar + abi + File.separatorChar + mappedLibName;
-                final ZipEntry zipEntry = zipFile.getEntry(libZipPath);
-                if (zipEntry == null)
-                    continue;
-                Log.d(TAG, "Extracting apk:/" + libZipPath + " to " + destination.getAbsolutePath());
-                try (final FileOutputStream out = new FileOutputStream(destination);
-                     final InputStream in = zipFile.getInputStream(zipEntry)) {
-                    int len;
-                    while ((len = in.read(buffer)) != -1) {
-                        out.write(buffer, 0, len);
-                    }
-                    out.getFD().sync();
-                }
-                zipFile.close();
-                return true;
-            }
-        }
-        return false;
-    }
-
-    public static void loadSharedLibrary(final Context context, final String libName) {
-        Throwable noAbiException;
-        try {
-            System.loadLibrary(libName);
-            return;
-        } catch (final UnsatisfiedLinkError e) {
-            Log.d(TAG, "Failed to load library normally, so attempting to extract from apk", e);
-            noAbiException = e;
-        }
-        File f = null;
-        try {
-            f = File.createTempFile("lib", ".so", context.getCodeCacheDir());
-            if (extractLibrary(context, libName, f)) {
-                System.load(f.getAbsolutePath());
-                return;
-            }
-        } catch (final Exception e) {
-            Log.d(TAG, "Failed to load library apk:/" + libName, e);
-            noAbiException = e;
-        } finally {
-            if (f != null)
-                // noinspection ResultOfMethodCallIgnored
-                f.delete();
-        }
-        if (noAbiException instanceof RuntimeException)
-            throw (RuntimeException) noAbiException;
-        throw new RuntimeException(noAbiException);
-    }
-}
diff --git a/app/src/main/java/com/wireguard/android/util/ToolsInstaller.java b/app/src/main/java/com/wireguard/android/util/ToolsInstaller.java
deleted file mode 100644
index ac18cabf..00000000
--- a/app/src/main/java/com/wireguard/android/util/ToolsInstaller.java
+++ /dev/null
@@ -1,196 +0,0 @@
-/*
- * Copyright © 2017-2019 WireGuard LLC. All Rights Reserved.
- * SPDX-License-Identifier: Apache-2.0
- */
-
-package com.wireguard.android.util;
-
-import android.content.Context;
-import androidx.annotation.Nullable;
-import android.system.OsConstants;
-import android.util.Log;
-
-import com.wireguard.android.util.RootShell.RootShellException;
-
-import java.io.File;
-import java.io.FileNotFoundException;
-import java.io.IOException;
-import java.util.Arrays;
-import java.util.List;
-
-/**
- * Helper to install WireGuard tools to the system partition.
- */
-
-public final class ToolsInstaller {
-    public static final int ERROR = 0x0;
-    public static final int MAGISK = 0x4;
-    public static final int NO = 0x2;
-    public static final int SYSTEM = 0x8;
-    public static final int YES = 0x1;
-    private static final String[] EXECUTABLES = {"wg", "wg-quick"};
-    private static final File[] INSTALL_DIRS = {
-            new File("/system/xbin"),
-            new File("/system/bin"),
-    };
-    @Nullable private static final File INSTALL_DIR = getInstallDir();
-    private static final String TAG = "WireGuard/" + ToolsInstaller.class.getSimpleName();
-
-    private final Context context;
-    private final RootShell rootShell;
-    private final File localBinaryDir;
-    private final Object lock = new Object();
-    @Nullable private Boolean areToolsAvailable;
-    @Nullable private Boolean installAsMagiskModule;
-
-    public ToolsInstaller(final Context context, final RootShell rootShell) {
-        localBinaryDir = new File(context.getCodeCacheDir(), "bin");
-        this.context = context;
-        this.rootShell = rootShell;
-    }
-
-    @Nullable
-    private static File getInstallDir() {
-        final String path = System.getenv("PATH");
-        if (path == null)
-            return INSTALL_DIRS[0];
-        final List<String> paths = Arrays.asList(path.split(":"));
-        for (final File dir : INSTALL_DIRS) {
-            if (paths.contains(dir.getPath()) && dir.isDirectory())
-                return dir;
-        }
-        return null;
-    }
-
-    public int areInstalled() throws RootShellException {
-        if (INSTALL_DIR == null)
-            return ERROR;
-        final StringBuilder script = new StringBuilder();
-        for (final String name : EXECUTABLES) {
-            script.append(String.format("cmp -s '%s' '%s' && ",
-                    new File(localBinaryDir, name).getAbsolutePath(),
-                    new File(INSTALL_DIR, name).getAbsolutePath()));
-        }
-        script.append("exit ").append(OsConstants.EALREADY).append(';');
-        try {
-            final int ret = rootShell.run(null, script.toString());
-            if (ret == OsConstants.EALREADY)
-                return willInstallAsMagiskModule() ? YES | MAGISK : YES | SYSTEM;
-            else
-                return willInstallAsMagiskModule() ? NO | MAGISK : NO | SYSTEM;
-        } catch (final IOException ignored) {
-            return ERROR;
-        } catch (final RootShellException e) {
-            if (e.isIORelated())
-                return ERROR;
-            throw e;
-        }
-    }
-
-    public void ensureToolsAvailable() throws FileNotFoundException {
-        synchronized (lock) {
-            if (areToolsAvailable == null) {
-                try {
-                    Log.d(TAG, extract() ? "Tools are now extracted into our private binary dir" :
-                            "Tools were already extracted into our private binary dir");
-                    areToolsAvailable = true;
-                } catch (final IOException e) {
-                    Log.e(TAG, "The wg and wg-quick tools are not available", e);
-                    areToolsAvailable = false;
-                }
-            }
-            if (!areToolsAvailable)
-                throw new FileNotFoundException("Required tools unavailable");
-        }
-    }
-
-    public int install() throws RootShellException, IOException {
-        if (!context.getPackageName().startsWith("com.wireguard."))
-            throw new SecurityException("The tools may only be installed system-wide from the main WireGuard app.");
-        return willInstallAsMagiskModule() ? installMagisk() : installSystem();
-    }
-
-    private int installMagisk() throws RootShellException, IOException {
-        extract();
-        final StringBuilder script = new StringBuilder("set -ex; ");
-
-        script.append("trap 'rm -rf /sbin/.magisk/img/wireguard' INT TERM EXIT; ");
-        script.append(String.format("rm -rf /sbin/.magisk/img/wireguard/; mkdir -p /sbin/.magisk/img/wireguard%s; ", INSTALL_DIR));
-        script.append("printf 'name=WireGuard Command Line Tools\nversion=1.0\nversionCode=1\nauthor=zx2c4\ndescription=Command line tools for WireGuard\nminMagisk=1500\n' > /sbin/.magisk/img/wireguard/module.prop; ");
-        script.append("touch /sbin/.magisk/img/wireguard/auto_mount; ");
-        for (final String name : EXECUTABLES) {
-            final File destination = new File("/sbin/.magisk/img/wireguard" + INSTALL_DIR, name);
-            script.append(String.format("cp '%s' '%s'; chmod 755 '%s'; chcon 'u:object_r:system_file:s0' '%s' || true; ",
-                    new File(localBinaryDir, name), destination, destination, destination));
-        }
-        script.append("trap - INT TERM EXIT;");
-
-        try {
-            return rootShell.run(null, script.toString()) == 0 ? YES | MAGISK : ERROR;
-        } catch (final IOException ignored) {
-            return ERROR;
-        } catch (final RootShellException e) {
-            if (e.isIORelated())
-                return ERROR;
-            throw e;
-        }
-    }
-
-    private int installSystem() throws RootShellException, IOException {
-        if (INSTALL_DIR == null)
-            return OsConstants.ENOENT;
-        extract();
-        final StringBuilder script = new StringBuilder("set -ex; ");
-        script.append("trap 'mount -o ro,remount /system' EXIT; mount -o rw,remount /system; ");
-        for (final String name : EXECUTABLES) {
-            final File destination = new File(INSTALL_DIR, name);
-            script.append(String.format("cp '%s' '%s'; chmod 755 '%s'; restorecon '%s' || true; ",
-                    new File(localBinaryDir, name), destination, destination, destination));
-        }
-        try {
-            return rootShell.run(null, script.toString()) == 0 ? YES | SYSTEM : ERROR;
-        } catch (final IOException ignored) {
-            return ERROR;
-        } catch (final RootShellException e) {
-            if (e.isIORelated())
-                return ERROR;
-            throw e;
-        }
-    }
-
-    public boolean extract() throws IOException {
-        localBinaryDir.mkdirs();
-        final File files[] = new File[EXECUTABLES.length];
-        final File tempFiles[] = new File[EXECUTABLES.length];
-        boolean allExist = true;
-        for (int i = 0; i < files.length; ++i) {
-            files[i] = new File(localBinaryDir, EXECUTABLES[i]);
-            tempFiles[i] = new File(localBinaryDir, EXECUTABLES[i] + ".tmp");
-            allExist &= files[i].exists();
-        }
-        if (allExist)
-            return false;
-        for (int i = 0; i < files.length; ++i) {
-            if (!SharedLibraryLoader.extractLibrary(context, EXECUTABLES[i], tempFiles[i]))
-                throw new FileNotFoundException("Unable to find " + EXECUTABLES[i]);
-            if (!tempFiles[i].setExecutable(true, false))
-                throw new IOException("Unable to mark " + tempFiles[i].getAbsolutePath() + " as executable");
-            if (!tempFiles[i].renameTo(files[i]))
-                throw new IOException("Unable to rename " + tempFiles[i].getAbsolutePath() + " to " + files[i].getAbsolutePath());
-        }
-        return true;
-    }
-
-    private boolean willInstallAsMagiskModule() {
-        synchronized (lock) {
-            if (installAsMagiskModule == null) {
-                try {
-                    installAsMagiskModule = rootShell.run(null, "[ -d /sbin/.magisk/mirror -a -d /sbin/.magisk/img -a ! -f /cache/.disable_magisk ]") == OsConstants.EXIT_SUCCESS;
-                } catch (final Exception ignored) {
-                    installAsMagiskModule = false;
-                }
-            }
-            return installAsMagiskModule;
-        }
-    }
-}
diff --git a/app/src/main/java/com/wireguard/config/Attribute.java b/app/src/main/java/com/wireguard/config/Attribute.java
deleted file mode 100644
index 1e9e25f0..00000000
--- a/app/src/main/java/com/wireguard/config/Attribute.java
+++ /dev/null
@@ -1,58 +0,0 @@
-/*
- * Copyright © 2018-2019 WireGuard LLC. All Rights Reserved.
- * SPDX-License-Identifier: Apache-2.0
- */
-
-package com.wireguard.config;
-
-import java.util.Iterator;
-import java.util.regex.Matcher;
-import java.util.regex.Pattern;
-
-import java9.util.Optional;
-
-public final class Attribute {
-    private static final Pattern LINE_PATTERN = Pattern.compile("(\\w+)\\s*=\\s*([^\\s#][^#]*)");
-    private static final Pattern LIST_SEPARATOR = Pattern.compile("\\s*,\\s*");
-
-    private final String key;
-    private final String value;
-
-    private Attribute(final String key, final String value) {
-        this.key = key;
-        this.value = value;
-    }
-
-    public static String join(final Iterable<?> values) {
-        final Iterator<?> it = values.iterator();
-        if (!it.hasNext()) {
-            return "";
-        }
-        final StringBuilder sb = new StringBuilder();
-        sb.append(it.next());
-        while (it.hasNext()) {
-            sb.append(", ");
-            sb.append(it.next());
-        }
-        return sb.toString();
-    }
-
-    public static Optional<Attribute> parse(final CharSequence line) {
-        final Matcher matcher = LINE_PATTERN.matcher(line);
-        if (!matcher.matches())
-            return Optional.empty();
-        return Optional.of(new Attribute(matcher.group(1), matcher.group(2)));
-    }
-
-    public static String[] split(final CharSequence value) {
-        return LIST_SEPARATOR.split(value);
-    }
-
-    public String getKey() {
-        return key;
-    }
-
-    public String getValue() {
-        return value;
-    }
-}
diff --git a/app/src/main/java/com/wireguard/config/BadConfigException.java b/app/src/main/java/com/wireguard/config/BadConfigException.java
deleted file mode 100644
index 6d41b065..00000000
--- a/app/src/main/java/com/wireguard/config/BadConfigException.java
+++ /dev/null
@@ -1,118 +0,0 @@
-/*
- * Copyright © 2018-2019 WireGuard LLC. All Rights Reserved.
- * SPDX-License-Identifier: Apache-2.0
- */
-
-package com.wireguard.config;
-
-import androidx.annotation.Nullable;
-
-import com.wireguard.crypto.KeyFormatException;
-
-public class BadConfigException extends Exception {
-    private final Location location;
-    private final Reason reason;
-    private final Section section;
-    @Nullable private final CharSequence text;
-
-    private BadConfigException(final Section section, final Location location,
-                               final Reason reason, @Nullable final CharSequence text,
-                               @Nullable final Throwable cause) {
-        super(cause);
-        this.section = section;
-        this.location = location;
-        this.reason = reason;
-        this.text = text;
-    }
-
-    public BadConfigException(final Section section, final Location location,
-                              final Reason reason, @Nullable final CharSequence text) {
-        this(section, location, reason, text, null);
-    }
-
-    public BadConfigException(final Section section, final Location location,
-                              final KeyFormatException cause) {
-        this(section, location, Reason.INVALID_KEY, null, cause);
-    }
-
-    public BadConfigException(final Section section, final Location location,
-                              @Nullable final CharSequence text,
-                              final NumberFormatException cause) {
-        this(section, location, Reason.INVALID_NUMBER, text, cause);
-    }
-
-    public BadConfigException(final Section section, final Location location,
-                              final ParseException cause) {
-        this(section, location, Reason.INVALID_VALUE, cause.getText(), cause);
-    }
-
-    public Location getLocation() {
-        return location;
-    }
-
-    public Reason getReason() {
-        return reason;
-    }
-
-    public Section getSection() {
-        return section;
-    }
-
-    @Nullable
-    public CharSequence getText() {
-        return text;
-    }
-
-    public enum Location {
-        TOP_LEVEL(""),
-        ADDRESS("Address"),
-        ALLOWED_IPS("AllowedIPs"),
-        DNS("DNS"),
-        ENDPOINT("Endpoint"),
-        EXCLUDED_APPLICATIONS("ExcludedApplications"),
-        LISTEN_PORT("ListenPort"),
-        MTU("MTU"),
-        PERSISTENT_KEEPALIVE("PersistentKeepalive"),
-        PRE_SHARED_KEY("PresharedKey"),
-        PRIVATE_KEY("PrivateKey"),
-        PUBLIC_KEY("PublicKey");
-
-        private final String name;
-
-        Location(final String name) {
-            this.name = name;
-        }
-
-        public String getName() {
-            return name;
-        }
-    }
-
-    public enum Reason {
-        INVALID_KEY,
-        INVALID_NUMBER,
-        INVALID_VALUE,
-        MISSING_ATTRIBUTE,
-        MISSING_SECTION,
-        MISSING_VALUE,
-        SYNTAX_ERROR,
-        UNKNOWN_ATTRIBUTE,
-        UNKNOWN_SECTION
-    }
-
-    public enum Section {
-        CONFIG("Config"),
-        INTERFACE("Interface"),
-        PEER("Peer");
-
-        private final String name;
-
-        Section(final String name) {
-            this.name = name;
-        }
-
-        public String getName() {
-            return name;
-        }
-    }
-}
diff --git a/app/src/main/java/com/wireguard/config/Config.java b/app/src/main/java/com/wireguard/config/Config.java
deleted file mode 100644
index 62651b08..00000000
--- a/app/src/main/java/com/wireguard/config/Config.java
+++ /dev/null
@@ -1,221 +0,0 @@
-/*
- * Copyright © 2017-2019 WireGuard LLC. All Rights Reserved.
- * SPDX-License-Identifier: Apache-2.0
- */
-
-package com.wireguard.config;
-
-import androidx.annotation.Nullable;
-
-import com.wireguard.config.BadConfigException.Location;
-import com.wireguard.config.BadConfigException.Reason;
-import com.wireguard.config.BadConfigException.Section;
-
-import java.io.BufferedReader;
-import java.io.IOException;
-import java.io.InputStream;
-import java.io.InputStreamReader;
-import java.util.ArrayList;
-import java.util.Collection;
-import java.util.Collections;
-import java.util.LinkedHashSet;
-import java.util.List;
-import java.util.Objects;
-import java.util.Set;
-
-/**
- * Represents the contents of a wg-quick configuration file, made up of one or more "Interface"
- * sections (combined together), and zero or more "Peer" sections (treated individually).
- * <p>
- * Instances of this class are immutable.
- */
-public final class Config {
-    private final Interface interfaze;
-    private final List<Peer> peers;
-
-    private Config(final Builder builder) {
-        interfaze = Objects.requireNonNull(builder.interfaze, "An [Interface] section is required");
-        // Defensively copy to ensure immutability even if the Builder is reused.
-        peers = Collections.unmodifiableList(new ArrayList<>(builder.peers));
-    }
-
-    /**
-     * Parses an series of "Interface" and "Peer" sections into a {@code Config}. Throws
-     * {@link BadConfigException} if the input is not well-formed or contains data that cannot
-     * be parsed.
-     *
-     * @param stream a stream of UTF-8 text that is interpreted as a WireGuard configuration
-     * @return a {@code Config} instance representing the supplied configuration
-     */
-    public static Config parse(final InputStream stream)
-            throws IOException, BadConfigException {
-        return parse(new BufferedReader(new InputStreamReader(stream)));
-    }
-
-    /**
-     * Parses an series of "Interface" and "Peer" sections into a {@code Config}. Throws
-     * {@link BadConfigException} if the input is not well-formed or contains data that cannot
-     * be parsed.
-     *
-     * @param reader a BufferedReader of UTF-8 text that is interpreted as a WireGuard configuration
-     * @return a {@code Config} instance representing the supplied configuration
-     */
-    public static Config parse(final BufferedReader reader)
-            throws IOException, BadConfigException {
-        final Builder builder = new Builder();
-        final Collection<String> interfaceLines = new ArrayList<>();
-        final Collection<String> peerLines = new ArrayList<>();
-        boolean inInterfaceSection = false;
-        boolean inPeerSection = false;
-        @Nullable String line;
-        while ((line = reader.readLine()) != null) {
-            final int commentIndex = line.indexOf('#');
-            if (commentIndex != -1)
-                line = line.substring(0, commentIndex);
-            line = line.trim();
-            if (line.isEmpty())
-                continue;
-            if (line.startsWith("[")) {
-                // Consume all [Peer] lines read so far.
-                if (inPeerSection) {
-                    builder.parsePeer(peerLines);
-                    peerLines.clear();
-                }
-                if ("[Interface]".equalsIgnoreCase(line)) {
-                    inInterfaceSection = true;
-                    inPeerSection = false;
-                } else if ("[Peer]".equalsIgnoreCase(line)) {
-                    inInterfaceSection = false;
-                    inPeerSection = true;
-                } else {
-                    throw new BadConfigException(Section.CONFIG, Location.TOP_LEVEL,
-                            Reason.UNKNOWN_SECTION, line);
-                }
-            } else if (inInterfaceSection) {
-                interfaceLines.add(line);
-            } else if (inPeerSection) {
-                peerLines.add(line);
-            } else {
-                throw new BadConfigException(Section.CONFIG, Location.TOP_LEVEL,
-                        Reason.UNKNOWN_SECTION, line);
-            }
-        }
-        if (inPeerSection)
-            builder.parsePeer(peerLines);
-        else if (!inInterfaceSection)
-            throw new BadConfigException(Section.CONFIG, Location.TOP_LEVEL,
-                    Reason.MISSING_SECTION, null);
-        // Combine all [Interface] sections in the file.
-        builder.parseInterface(interfaceLines);
-        return builder.build();
-    }
-
-    @Override
-    public boolean equals(final Object obj) {
-        if (!(obj instanceof Config))
-            return false;
-        final Config other = (Config) obj;
-        return interfaze.equals(other.interfaze) && peers.equals(other.peers);
-    }
-
-    /**
-     * Returns the interface section of the configuration.
-     *
-     * @return the interface configuration
-     */
-    public Interface getInterface() {
-        return interfaze;
-    }
-
-    /**
-     * Returns a list of the configuration's peer sections.
-     *
-     * @return a list of {@link Peer}s
-     */
-    public List<Peer> getPeers() {
-        return peers;
-    }
-
-    @Override
-    public int hashCode() {
-        return 31 * interfaze.hashCode() + peers.hashCode();
-    }
-
-    /**
-     * Converts the {@code Config} into a string suitable for debugging purposes. The {@code Config}
-     * is identified by its interface's public key and the number of peers it has.
-     *
-     * @return a concise single-line identifier for the {@code Config}
-     */
-    @Override
-    public String toString() {
-        return "(Config " + interfaze + " (" + peers.size() + " peers))";
-    }
-
-    /**
-     * Converts the {@code Config} into a string suitable for use as a {@code wg-quick}
-     * configuration file.
-     *
-     * @return the {@code Config} represented as one [Interface] and zero or more [Peer] sections
-     */
-    public String toWgQuickString() {
-        final StringBuilder sb = new StringBuilder();
-        sb.append("[Interface]\n").append(interfaze.toWgQuickString());
-        for (final Peer peer : peers)
-            sb.append("\n[Peer]\n").append(peer.toWgQuickString());
-        return sb.toString();
-    }
-
-    /**
-     * Serializes the {@code Config} for use with the WireGuard cross-platform userspace API.
-     *
-     * @return the {@code Config} represented as a series of "key=value" lines
-     */
-    public String toWgUserspaceString() {
-        final StringBuilder sb = new StringBuilder();
-        sb.append(interfaze.toWgUserspaceString());
-        sb.append("replace_peers=true\n");
-        for (final Peer peer : peers)
-            sb.append(peer.toWgUserspaceString());
-        return sb.toString();
-    }
-
-    @SuppressWarnings("UnusedReturnValue")
-    public static final class Builder {
-        // Defaults to an empty set.
-        private final Set<Peer> peers = new LinkedHashSet<>();
-        // No default; must be provided before building.
-        @Nullable private Interface interfaze;
-
-        public Builder addPeer(final Peer peer) {
-            peers.add(peer);
-            return this;
-        }
-
-        public Builder addPeers(final Collection<Peer> peers) {
-            this.peers.addAll(peers);
-            return this;
-        }
-
-        public Config build() {
-            if (interfaze == null)
-                throw new IllegalArgumentException("An [Interface] section is required");
-            return new Config(this);
-        }
-
-        public Builder parseInterface(final Iterable<? extends CharSequence> lines)
-                throws BadConfigException {
-            return setInterface(Interface.parse(lines));
-        }
-
-        public Builder parsePeer(final Iterable<? extends CharSequence> lines)
-                throws BadConfigException {
-            return addPeer(Peer.parse(lines));
-        }
-
-        public Builder setInterface(final Interface interfaze) {
-            this.interfaze = interfaze;
-            return this;
-        }
-    }
-}
diff --git a/app/src/main/java/com/wireguard/config/InetAddresses.java b/app/src/main/java/com/wireguard/config/InetAddresses.java
deleted file mode 100644
index 5303e27f..00000000
--- a/app/src/main/java/com/wireguard/config/InetAddresses.java
+++ /dev/null
@@ -1,71 +0,0 @@
-/*
- * Copyright © 2017-2019 WireGuard LLC. All Rights Reserved.
- * SPDX-License-Identifier: Apache-2.0
- */
-
-package com.wireguard.config;
-
-import java.lang.reflect.Method;
-import java.net.Inet4Address;
-import java.net.Inet6Address;
-import java.net.InetAddress;
-import java.net.UnknownHostException;
-import java.util.regex.Pattern;
-
-import javax.annotation.Nullable;
-
-/**
- * Utility methods for creating instances of {@link InetAddress}.
- */
-public final class InetAddresses {
-    @Nullable private static final Method PARSER_METHOD;
-    private static final Pattern WONT_TOUCH_RESOLVER = Pattern.compile("^(((([0-9A-Fa-f]{1,4}:){7}([0-9A-Fa-f]{1,4}|:))|(([0-9A-Fa-f]{1,4}:){6}(:[0-9A-Fa-f]{1,4}|((25[0-5]|2[0-4]\\d|1\\d\\d|[1-9]?\\d)(\\.(25[0-5]|2[0-4]\\d|1\\d\\d|[1-9]?\\d)){3})|:))|(([0-9A-Fa-f]{1,4}:){5}(((:[0-9A-Fa-f]{1,4}){1,2})|:((25[0-5]|2[0-4]\\d|1\\d\\d|[1-9]?\\d)(\\.(25[0-5]|2[0-4]\\d|1\\d\\d|[1-9]?\\d)){3})|:))|(([0-9A-Fa-f]{1,4}:){4}(((:[0-9A-Fa-f]{1,4}){1,3})|((:[0-9A-Fa-f]{1,4})?:((25[0-5]|2[0-4]\\d|1\\d\\d|[1-9]?\\d)(\\.(25[0-5]|2[0-4]\\d|1\\d\\d|[1-9]?\\d)){3}))|:))|(([0-9A-Fa-f]{1,4}:){3}(((:[0-9A-Fa-f]{1,4}){1,4})|((:[0-9A-Fa-f]{1,4}){0,2}:((25[0-5]|2[0-4]\\d|1\\d\\d|[1-9]?\\d)(\\.(25[0-5]|2[0-4]\\d|1\\d\\d|[1-9]?\\d)){3}))|:))|(([0-9A-Fa-f]{1,4}:){2}(((:[0-9A-Fa-f]{1,4}){1,5})|((:[0-9A-Fa-f]{1,4}){0,3}:((25[0-5]|2[0-4]\\d|1\\d\\d|[1-9]?\\d)(\\.(25[0-5]|2[0-4]\\d|1\\d\\d|[1-9]?\\d)){3}))|:))|(([0-9A-Fa-f]{1,4}:){1}(((:[0-9A-Fa-f]{1,4}){1,6})|((:[0-9A-Fa-f]{1,4}){0,4}:((25[0-5]|2[0-4]\\d|1\\d\\d|[1-9]?\\d)(\\.(25[0-5]|2[0-4]\\d|1\\d\\d|[1-9]?\\d)){3}))|:))|(:(((:[0-9A-Fa-f]{1,4}){1,7})|((:[0-9A-Fa-f]{1,4}){0,5}:((25[0-5]|2[0-4]\\d|1\\d\\d|[1-9]?\\d)(\\.(25[0-5]|2[0-4]\\d|1\\d\\d|[1-9]?\\d)){3}))|:)))(%.+)?)|((?:(?:25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)\\.){3}(?:25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?))$");
-
-    static {
-        Method m = null;
-        try {
-            if (android.os.Build.VERSION.SDK_INT < android.os.Build.VERSION_CODES.Q)
-                // noinspection JavaReflectionMemberAccess
-                m = InetAddress.class.getMethod("parseNumericAddress", String.class);
-        } catch (final Exception ignored) {
-        }
-        PARSER_METHOD = m;
-    }
-
-    private InetAddresses() { }
-
-    /**
-     * Parses a numeric IPv4 or IPv6 address without performing any DNS lookups.
-     *
-     * @param address a string representing the IP address
-     * @return an instance of {@link Inet4Address} or {@link Inet6Address}, as appropriate
-     */
-    public static InetAddress parse(final String address) throws ParseException {
-        if (address.isEmpty())
-            throw new ParseException(InetAddress.class, address, "Empty address");
-        try {
-            if (android.os.Build.VERSION.SDK_INT >= android.os.Build.VERSION_CODES.Q)
-                return android.net.InetAddresses.parseNumericAddress(address);
-            else if (PARSER_METHOD != null)
-                return (InetAddress) PARSER_METHOD.invoke(null, address);
-            else
-                throw new NoSuchMethodException("parseNumericAddress");
-        } catch (final IllegalArgumentException e) {
-            throw new ParseException(InetAddress.class, address, e);
-        } catch (final Exception e) {
-            final Throwable cause = e.getCause();
-            // Re-throw parsing exceptions with the original type, as callers might try to catch
-            // them. On the other hand, callers cannot be expected to handle reflection failures.
-            if (cause instanceof IllegalArgumentException)
-                throw new ParseException(InetAddress.class, address, cause);
-            try {
-                if (WONT_TOUCH_RESOLVER.matcher(address).matches())
-                    return InetAddress.getByName(address);
-                else
-                    throw new ParseException(InetAddress.class, address, "Not an IP address");
-            } catch (final UnknownHostException f) {
-                throw new ParseException(InetAddress.class, address, f);
-            }
-        }
-    }
-}
diff --git a/app/src/main/java/com/wireguard/config/InetEndpoint.java b/app/src/main/java/com/wireguard/config/InetEndpoint.java
deleted file mode 100644
index a442258e..00000000
--- a/app/src/main/java/com/wireguard/config/InetEndpoint.java
+++ /dev/null
@@ -1,125 +0,0 @@
-/*
- * Copyright © 2017-2019 WireGuard LLC. All Rights Reserved.
- * SPDX-License-Identifier: Apache-2.0
- */
-
-package com.wireguard.config;
-
-import androidx.annotation.Nullable;
-
-import org.threeten.bp.Duration;
-import org.threeten.bp.Instant;
-
-import java.net.Inet4Address;
-import java.net.InetAddress;
-import java.net.URI;
-import java.net.URISyntaxException;
-import java.net.UnknownHostException;
-import java.util.regex.Pattern;
-
-import java9.util.Optional;
-
-
-/**
- * An external endpoint (host and port) used to connect to a WireGuard {@link Peer}.
- * <p>
- * Instances of this class are externally immutable.
- */
-public final class InetEndpoint {
-    private static final Pattern BARE_IPV6 = Pattern.compile("^[^\\[\\]]*:[^\\[\\]]*");
-    private static final Pattern FORBIDDEN_CHARACTERS = Pattern.compile("[/?#]");
-
-    private final String host;
-    private final boolean isResolved;
-    private final Object lock = new Object();
-    private final int port;
-    private Instant lastResolution = Instant.EPOCH;
-    @Nullable private InetEndpoint resolved;
-
-    private InetEndpoint(final String host, final boolean isResolved, final int port) {
-        this.host = host;
-        this.isResolved = isResolved;
-        this.port = port;
-    }
-
-    public static InetEndpoint parse(final String endpoint) throws ParseException {
-        if (FORBIDDEN_CHARACTERS.matcher(endpoint).find())
-            throw new ParseException(InetEndpoint.class, endpoint, "Forbidden characters");
-        final URI uri;
-        try {
-            uri = new URI("wg://" + endpoint);
-        } catch (final URISyntaxException e) {
-            throw new IllegalArgumentException(e);
-        }
-        if (uri.getPort() < 0 || uri.getPort() > 65535)
-            throw new ParseException(InetEndpoint.class, endpoint, "Missing/invalid port number");
-        try {
-            InetAddresses.parse(uri.getHost());
-            // Parsing ths host as a numeric address worked, so we don't need to do DNS lookups.
-            return new InetEndpoint(uri.getHost(), true, uri.getPort());
-        } catch (final ParseException ignored) {
-            // Failed to parse the host as a numeric address, so it must be a DNS hostname/FQDN.
-            return new InetEndpoint(uri.getHost(), false, uri.getPort());
-        }
-    }
-
-    @Override
-    public boolean equals(final Object obj) {
-        if (!(obj instanceof InetEndpoint))
-            return false;
-        final InetEndpoint other = (InetEndpoint) obj;
-        return host.equals(other.host) && port == other.port;
-    }
-
-    public String getHost() {
-        return host;
-    }
-
-    public int getPort() {
-        return port;
-    }
-
-    /**
-     * Generate an {@code InetEndpoint} instance with the same port and the host resolved using DNS
-     * to a numeric address. If the host is already numeric, the existing instance may be returned.
-     * Because this function may perform network I/O, it must not be called from the main thread.
-     *
-     * @return the resolved endpoint, or {@link Optional#empty()}
-     */
-    public Optional<InetEndpoint> getResolved() {
-        if (isResolved)
-            return Optional.of(this);
-        synchronized (lock) {
-            //TODO(zx2c4): Implement a real timeout mechanism using DNS TTL
-            if (Duration.between(lastResolution, Instant.now()).toMinutes() > 1) {
-                try {
-                    // Prefer v4 endpoints over v6 to work around DNS64 and IPv6 NAT issues.
-                    final InetAddress[] candidates = InetAddress.getAllByName(host);
-                    InetAddress address = candidates[0];
-                    for (final InetAddress candidate : candidates) {
-                        if (candidate instanceof Inet4Address) {
-                            address = candidate;
-                            break;
-                        }
-                    }
-                    resolved = new InetEndpoint(address.getHostAddress(), true, port);
-                    lastResolution = Instant.now();
-                } catch (final UnknownHostException e) {
-                    resolved = null;
-                }
-            }
-            return Optional.ofNullable(resolved);
-        }
-    }
-
-    @Override
-    public int hashCode() {
-        return host.hashCode() ^ port;
-    }
-
-    @Override
-    public String toString() {
-        final boolean isBareIpv6 = isResolved && BARE_IPV6.matcher(host).matches();
-        return (isBareIpv6 ? '[' + host + ']' : host) + ':' + port;
-    }
-}
diff --git a/app/src/main/java/com/wireguard/config/InetNetwork.java b/app/src/main/java/com/wireguard/config/InetNetwork.java
deleted file mode 100644
index f89322fd..00000000
--- a/app/src/main/java/com/wireguard/config/InetNetwork.java
+++ /dev/null
@@ -1,76 +0,0 @@
-/*
- * Copyright © 2017-2019 WireGuard LLC. All Rights Reserved.
- * SPDX-License-Identifier: Apache-2.0
- */
-
-package com.wireguard.config;
-
-import java.net.Inet4Address;
-import java.net.InetAddress;
-
-/**
- * An Internet network, denoted by its address and netmask
- * <p>
- * Instances of this class are immutable.
- */
-public final class InetNetwork {
-    private final InetAddress address;
-    private final int mask;
-
-    private InetNetwork(final InetAddress address, final int mask) {
-        this.address = address;
-        this.mask = mask;
-    }
-
-    public static InetNetwork parse(final String network) throws ParseException {
-        final int slash = network.lastIndexOf('/');
-        final String maskString;
-        final int rawMask;
-        final String rawAddress;
-        if (slash >= 0) {
-            maskString = network.substring(slash + 1);
-            try {
-                rawMask = Integer.parseInt(maskString, 10);
-            } catch (final NumberFormatException ignored) {
-                throw new ParseException(Integer.class, maskString);
-            }
-            rawAddress = network.substring(0, slash);
-        } else {
-            maskString = "";
-            rawMask = -1;
-            rawAddress = network;
-        }
-        final InetAddress address = InetAddresses.parse(rawAddress);
-        final int maxMask = (address instanceof Inet4Address) ? 32 : 128;
-        if (rawMask > maxMask)
-            throw new ParseException(InetNetwork.class, maskString, "Invalid network mask");
-        final int mask = rawMask >= 0 && rawMask <= maxMask ? rawMask : maxMask;
-        return new InetNetwork(address, mask);
-    }
-
-    @Override
-    public boolean equals(final Object obj) {
-        if (!(obj instanceof InetNetwork))
-            return false;
-        final InetNetwork other = (InetNetwork) obj;
-        return address.equals(other.address) && mask == other.mask;
-    }
-
-    public InetAddress getAddress() {
-        return address;
-    }
-
-    public int getMask() {
-        return mask;
-    }
-
-    @Override
-    public int hashCode() {
-        return address.hashCode() ^ mask;
-    }
-
-    @Override
-    public String toString() {
-        return address.getHostAddress() + '/' + mask;
-    }
-}
diff --git a/app/src/main/java/com/wireguard/config/Interface.java b/app/src/main/java/com/wireguard/config/Interface.java
deleted file mode 100644
index 54944424..00000000
--- a/app/src/main/java/com/wireguard/config/Interface.java
+++ /dev/null
@@ -1,355 +0,0 @@
-/*
- * Copyright © 2017-2019 WireGuard LLC. All Rights Reserved.
- * SPDX-License-Identifier: Apache-2.0
- */
-
-package com.wireguard.config;
-
-import androidx.annotation.Nullable;
-
-import com.wireguard.config.BadConfigException.Location;
-import com.wireguard.config.BadConfigException.Reason;
-import com.wireguard.config.BadConfigException.Section;
-import com.wireguard.crypto.Key;
-import com.wireguard.crypto.KeyFormatException;
-import com.wireguard.crypto.KeyPair;
-
-import java.net.InetAddress;
-import java.util.Collection;
-import java.util.Collections;
-import java.util.LinkedHashSet;
-import java.util.List;
-import java.util.Locale;
-import java.util.Objects;
-import java.util.Set;
-
-import java9.util.Lists;
-import java9.util.Optional;
-import java9.util.stream.Collectors;
-import java9.util.stream.StreamSupport;
-
-/**
- * Represents the configuration for a WireGuard interface (an [Interface] block). Interfaces must
- * have a private key (used to initialize a {@code KeyPair}), and may optionally have several other
- * attributes.
- * <p>
- * Instances of this class are immutable.
- */
-public final class Interface {
-    private static final int MAX_UDP_PORT = 65535;
-    private static final int MIN_UDP_PORT = 0;
-
-    private final Set<InetNetwork> addresses;
-    private final Set<InetAddress> dnsServers;
-    private final Set<String> excludedApplications;
-    private final KeyPair keyPair;
-    private final Optional<Integer> listenPort;
-    private final Optional<Integer> mtu;
-
-    private Interface(final Builder builder) {
-        // Defensively copy to ensure immutability even if the Builder is reused.
-        addresses = Collections.unmodifiableSet(new LinkedHashSet<>(builder.addresses));
-        dnsServers = Collections.unmodifiableSet(new LinkedHashSet<>(builder.dnsServers));
-        excludedApplications = Collections.unmodifiableSet(new LinkedHashSet<>(builder.excludedApplications));
-        keyPair = Objects.requireNonNull(builder.keyPair, "Interfaces must have a private key");
-        listenPort = builder.listenPort;
-        mtu = builder.mtu;
-    }
-
-    /**
-     * Parses an series of "KEY = VALUE" lines into an {@code Interface}. Throws
-     * {@link ParseException} if the input is not well-formed or contains unknown attributes.
-     *
-     * @param lines An iterable sequence of lines, containing at least a private key attribute
-     * @return An {@code Interface} with all of the attributes from {@code lines} set
-     */
-    public static Interface parse(final Iterable<? extends CharSequence> lines)
-            throws BadConfigException {
-        final Builder builder = new Builder();
-        for (final CharSequence line : lines) {
-            final Attribute attribute = Attribute.parse(line).orElseThrow(() ->
-                    new BadConfigException(Section.INTERFACE, Location.TOP_LEVEL,
-                            Reason.SYNTAX_ERROR, line));
-            switch (attribute.getKey().toLowerCase(Locale.ENGLISH)) {
-                case "address":
-                    builder.parseAddresses(attribute.getValue());
-                    break;
-                case "dns":
-                    builder.parseDnsServers(attribute.getValue());
-                    break;
-                case "excludedapplications":
-                    builder.parseExcludedApplications(attribute.getValue());
-                    break;
-                case "listenport":
-                    builder.parseListenPort(attribute.getValue());
-                    break;
-                case "mtu":
-                    builder.parseMtu(attribute.getValue());
-                    break;
-                case "privatekey":
-                    builder.parsePrivateKey(attribute.getValue());
-                    break;
-                default:
-                    throw new BadConfigException(Section.INTERFACE, Location.TOP_LEVEL,
-                            Reason.UNKNOWN_ATTRIBUTE, attribute.getKey());
-            }
-        }
-        return builder.build();
-    }
-
-    @Override
-    public boolean equals(final Object obj) {
-        if (!(obj instanceof Interface))
-            return false;
-        final Interface other = (Interface) obj;
-        return addresses.equals(other.addresses)
-                && dnsServers.equals(other.dnsServers)
-                && excludedApplications.equals(other.excludedApplications)
-                && keyPair.equals(other.keyPair)
-                && listenPort.equals(other.listenPort)
-                && mtu.equals(other.mtu);
-    }
-
-    /**
-     * Returns the set of IP addresses assigned to the interface.
-     *
-     * @return a set of {@link InetNetwork}s
-     */
-    public Set<InetNetwork> getAddresses() {
-        // The collection is already immutable.
-        return addresses;
-    }
-
-    /**
-     * Returns the set of DNS servers associated with the interface.
-     *
-     * @return a set of {@link InetAddress}es
-     */
-    public Set<InetAddress> getDnsServers() {
-        // The collection is already immutable.
-        return dnsServers;
-    }
-
-    /**
-     * Returns the set of applications excluded from using the interface.
-     *
-     * @return a set of package names
-     */
-    public Set<String> getExcludedApplications() {
-        // The collection is already immutable.
-        return excludedApplications;
-    }
-
-    /**
-     * Returns the public/private key pair used by the interface.
-     *
-     * @return a key pair
-     */
-    public KeyPair getKeyPair() {
-        return keyPair;
-    }
-
-    /**
-     * Returns the UDP port number that the WireGuard interface will listen on.
-     *
-     * @return a UDP port number, or {@code Optional.empty()} if none is configured
-     */
-    public Optional<Integer> getListenPort() {
-        return listenPort;
-    }
-
-    /**
-     * Returns the MTU used for the WireGuard interface.
-     *
-     * @return the MTU, or {@code Optional.empty()} if none is configured
-     */
-    public Optional<Integer> getMtu() {
-        return mtu;
-    }
-
-    @Override
-    public int hashCode() {
-        int hash = 1;
-        hash = 31 * hash + addresses.hashCode();
-        hash = 31 * hash + dnsServers.hashCode();
-        hash = 31 * hash + excludedApplications.hashCode();
-        hash = 31 * hash + keyPair.hashCode();
-        hash = 31 * hash + listenPort.hashCode();
-        hash = 31 * hash + mtu.hashCode();
-        return hash;
-    }
-
-    /**
-     * Converts the {@code Interface} into a string suitable for debugging purposes. The {@code
-     * Interface} is identified by its public key and (if set) the port used for its UDP socket.
-     *
-     * @return A concise single-line identifier for the {@code Interface}
-     */
-    @Override
-    public String toString() {
-        final StringBuilder sb = new StringBuilder("(Interface ");
-        sb.append(keyPair.getPublicKey().toBase64());
-        listenPort.ifPresent(lp -> sb.append(" @").append(lp));
-        sb.append(')');
-        return sb.toString();
-    }
-
-    /**
-     * Converts the {@code Interface} into a string suitable for inclusion in a {@code wg-quick}
-     * configuration file.
-     *
-     * @return The {@code Interface} represented as a series of "Key = Value" lines
-     */
-    public String toWgQuickString() {
-        final StringBuilder sb = new StringBuilder();
-        if (!addresses.isEmpty())
-            sb.append("Address = ").append(Attribute.join(addresses)).append('\n');
-        if (!dnsServers.isEmpty()) {
-            final List<String> dnsServerStrings = StreamSupport.stream(dnsServers)
-                    .map(InetAddress::getHostAddress)
-                    .collect(Collectors.toUnmodifiableList());
-            sb.append("DNS = ").append(Attribute.join(dnsServerStrings)).append('\n');
-        }
-        if (!excludedApplications.isEmpty())
-            sb.append("ExcludedApplications = ").append(Attribute.join(excludedApplications)).append('\n');
-        listenPort.ifPresent(lp -> sb.append("ListenPort = ").append(lp).append('\n'));
-        mtu.ifPresent(m -> sb.append("MTU = ").append(m).append('\n'));
-        sb.append("PrivateKey = ").append(keyPair.getPrivateKey().toBase64()).append('\n');
-        return sb.toString();
-    }
-
-    /**
-     * Serializes the {@code Interface} for use with the WireGuard cross-platform userspace API.
-     * Note that not all attributes are included in this representation.
-     *
-     * @return the {@code Interface} represented as a series of "KEY=VALUE" lines
-     */
-    public String toWgUserspaceString() {
-        final StringBuilder sb = new StringBuilder();
-        sb.append("private_key=").append(keyPair.getPrivateKey().toHex()).append('\n');
-        listenPort.ifPresent(lp -> sb.append("listen_port=").append(lp).append('\n'));
-        return sb.toString();
-    }
-
-    @SuppressWarnings("UnusedReturnValue")
-    public static final class Builder {
-        // Defaults to an empty set.
-        private final Set<InetNetwork> addresses = new LinkedHashSet<>();
-        // Defaults to an empty set.
-        private final Set<InetAddress> dnsServers = new LinkedHashSet<>();
-        // Defaults to an empty set.
-        private final Set<String> excludedApplications = new LinkedHashSet<>();
-        // No default; must be provided before building.
-        @Nullable private KeyPair keyPair;
-        // Defaults to not present.
-        private Optional<Integer> listenPort = Optional.empty();
-        // Defaults to not present.
-        private Optional<Integer> mtu = Optional.empty();
-
-        public Builder addAddress(final InetNetwork address) {
-            addresses.add(address);
-            return this;
-        }
-
-        public Builder addAddresses(final Collection<InetNetwork> addresses) {
-            this.addresses.addAll(addresses);
-            return this;
-        }
-
-        public Builder addDnsServer(final InetAddress dnsServer) {
-            dnsServers.add(dnsServer);
-            return this;
-        }
-
-        public Builder addDnsServers(final Collection<? extends InetAddress> dnsServers) {
-            this.dnsServers.addAll(dnsServers);
-            return this;
-        }
-
-        public Interface build() throws BadConfigException {
-            if (keyPair == null)
-                throw new BadConfigException(Section.INTERFACE, Location.PRIVATE_KEY,
-                        Reason.MISSING_ATTRIBUTE, null);
-            return new Interface(this);
-        }
-
-        public Builder excludeApplication(final String application) {
-            excludedApplications.add(application);
-            return this;
-        }
-
-        public Builder excludeApplications(final Collection<String> applications) {
-            excludedApplications.addAll(applications);
-            return this;
-        }
-
-        public Builder parseAddresses(final CharSequence addresses) throws BadConfigException {
-            try {
-                for (final String address : Attribute.split(addresses))
-                    addAddress(InetNetwork.parse(address));
-                return this;
-            } catch (final ParseException e) {
-                throw new BadConfigException(Section.INTERFACE, Location.ADDRESS, e);
-            }
-        }
-
-        public Builder parseDnsServers(final CharSequence dnsServers) throws BadConfigException {
-            try {
-                for (final String dnsServer : Attribute.split(dnsServers))
-                    addDnsServer(InetAddresses.parse(dnsServer));
-                return this;
-            } catch (final ParseException e) {
-                throw new BadConfigException(Section.INTERFACE, Location.DNS, e);
-            }
-        }
-
-        public Builder parseExcludedApplications(final CharSequence apps) {
-            return excludeApplications(Lists.of(Attribute.split(apps)));
-        }
-
-        public Builder parseListenPort(final String listenPort) throws BadConfigException {
-            try {
-                return setListenPort(Integer.parseInt(listenPort));
-            } catch (final NumberFormatException e) {
-                throw new BadConfigException(Section.INTERFACE, Location.LISTEN_PORT, listenPort, e);
-            }
-        }
-
-        public Builder parseMtu(final String mtu) throws BadConfigException {
-            try {
-                return setMtu(Integer.parseInt(mtu));
-            } catch (final NumberFormatException e) {
-                throw new BadConfigException(Section.INTERFACE, Location.MTU, mtu, e);
-            }
-        }
-
-        public Builder parsePrivateKey(final String privateKey) throws BadConfigException {
-            try {
-                return setKeyPair(new KeyPair(Key.fromBase64(privateKey)));
-            } catch (final KeyFormatException e) {
-                throw new BadConfigException(Section.INTERFACE, Location.PRIVATE_KEY, e);
-            }
-        }
-
-        public Builder setKeyPair(final KeyPair keyPair) {
-            this.keyPair = keyPair;
-            return this;
-        }
-
-        public Builder setListenPort(final int listenPort) throws BadConfigException {
-            if (listenPort < MIN_UDP_PORT || listenPort > MAX_UDP_PORT)
-                throw new BadConfigException(Section.INTERFACE, Location.LISTEN_PORT,
-                        Reason.INVALID_VALUE, String.valueOf(listenPort));
-            this.listenPort = listenPort == 0 ? Optional.empty() : Optional.of(listenPort);
-            return this;
-        }
-
-        public Builder setMtu(final int mtu) throws BadConfigException {
-            if (mtu < 0)
-                throw new BadConfigException(Section.INTERFACE, Location.LISTEN_PORT,
-                        Reason.INVALID_VALUE, String.valueOf(mtu));
-            this.mtu = mtu == 0 ? Optional.empty() : Optional.of(mtu);
-            return this;
-        }
-    }
-}
diff --git a/app/src/main/java/com/wireguard/config/ParseException.java b/app/src/main/java/com/wireguard/config/ParseException.java
deleted file mode 100644
index c79d1fa1..00000000
--- a/app/src/main/java/com/wireguard/config/ParseException.java
+++ /dev/null
@@ -1,44 +0,0 @@
-/*
- * Copyright © 2018-2019 WireGuard LLC. All Rights Reserved.
- * SPDX-License-Identifier: Apache-2.0
- */
-
-package com.wireguard.config;
-
-import androidx.annotation.Nullable;
-
-/**
- */
-public class ParseException extends Exception {
-    private final Class<?> parsingClass;
-    private final CharSequence text;
-
-    public ParseException(final Class<?> parsingClass, final CharSequence text,
-                          @Nullable final String message, @Nullable final Throwable cause) {
-        super(message, cause);
-        this.parsingClass = parsingClass;
-        this.text = text;
-    }
-
-    public ParseException(final Class<?> parsingClass, final CharSequence text,
-                          @Nullable final String message) {
-        this(parsingClass, text, message, null);
-    }
-
-    public ParseException(final Class<?> parsingClass, final CharSequence text,
-                          @Nullable final Throwable cause) {
-        this(parsingClass, text, null, cause);
-    }
-
-    public ParseException(final Class<?> parsingClass, final CharSequence text) {
-        this(parsingClass, text, null, null);
-    }
-
-    public Class<?> getParsingClass() {
-        return parsingClass;
-    }
-
-    public CharSequence getText() {
-        return text;
-    }
-}
diff --git a/app/src/main/java/com/wireguard/config/Peer.java b/app/src/main/java/com/wireguard/config/Peer.java
deleted file mode 100644
index 37fcfa69..00000000
--- a/app/src/main/java/com/wireguard/config/Peer.java
+++ /dev/null
@@ -1,306 +0,0 @@
-/*
- * Copyright © 2017-2019 WireGuard LLC. All Rights Reserved.
- * SPDX-License-Identifier: Apache-2.0
- */
-
-package com.wireguard.config;
-
-import androidx.annotation.Nullable;
-
-import com.wireguard.config.BadConfigException.Location;
-import com.wireguard.config.BadConfigException.Reason;
-import com.wireguard.config.BadConfigException.Section;
-import com.wireguard.crypto.Key;
-import com.wireguard.crypto.KeyFormatException;
-
-import java.util.Collection;
-import java.util.Collections;
-import java.util.LinkedHashSet;
-import java.util.Locale;
-import java.util.Objects;
-import java.util.Set;
-
-import java9.util.Optional;
-
-/**
- * Represents the configuration for a WireGuard peer (a [Peer] block). Peers must have a public key,
- * and may optionally have several other attributes.
- * <p>
- * Instances of this class are immutable.
- */
-public final class Peer {
-    private final Set<InetNetwork> allowedIps;
-    private final Optional<InetEndpoint> endpoint;
-    private final Optional<Integer> persistentKeepalive;
-    private final Optional<Key> preSharedKey;
-    private final Key publicKey;
-
-    private Peer(final Builder builder) {
-        // Defensively copy to ensure immutability even if the Builder is reused.
-        allowedIps = Collections.unmodifiableSet(new LinkedHashSet<>(builder.allowedIps));
-        endpoint = builder.endpoint;
-        persistentKeepalive = builder.persistentKeepalive;
-        preSharedKey = builder.preSharedKey;
-        publicKey = Objects.requireNonNull(builder.publicKey, "Peers must have a public key");
-    }
-
-    /**
-     * Parses an series of "KEY = VALUE" lines into a {@code Peer}. Throws {@link ParseException} if
-     * the input is not well-formed or contains unknown attributes.
-     *
-     * @param lines an iterable sequence of lines, containing at least a public key attribute
-     * @return a {@code Peer} with all of its attributes set from {@code lines}
-     */
-    public static Peer parse(final Iterable<? extends CharSequence> lines)
-            throws BadConfigException {
-        final Builder builder = new Builder();
-        for (final CharSequence line : lines) {
-            final Attribute attribute = Attribute.parse(line).orElseThrow(() ->
-                    new BadConfigException(Section.PEER, Location.TOP_LEVEL,
-                            Reason.SYNTAX_ERROR, line));
-            switch (attribute.getKey().toLowerCase(Locale.ENGLISH)) {
-                case "allowedips":
-                    builder.parseAllowedIPs(attribute.getValue());
-                    break;
-                case "endpoint":
-                    builder.parseEndpoint(attribute.getValue());
-                    break;
-                case "persistentkeepalive":
-                    builder.parsePersistentKeepalive(attribute.getValue());
-                    break;
-                case "presharedkey":
-                    builder.parsePreSharedKey(attribute.getValue());
-                    break;
-                case "publickey":
-                    builder.parsePublicKey(attribute.getValue());
-                    break;
-                default:
-                    throw new BadConfigException(Section.PEER, Location.TOP_LEVEL,
-                            Reason.UNKNOWN_ATTRIBUTE, attribute.getKey());
-            }
-        }
-        return builder.build();
-    }
-
-    @Override
-    public boolean equals(final Object obj) {
-        if (!(obj instanceof Peer))
-            return false;
-        final Peer other = (Peer) obj;
-        return allowedIps.equals(other.allowedIps)
-                && endpoint.equals(other.endpoint)
-                && persistentKeepalive.equals(other.persistentKeepalive)
-                && preSharedKey.equals(other.preSharedKey)
-                && publicKey.equals(other.publicKey);
-    }
-
-    /**
-     * Returns the peer's set of allowed IPs.
-     *
-     * @return the set of allowed IPs
-     */
-    public Set<InetNetwork> getAllowedIps() {
-        // The collection is already immutable.
-        return allowedIps;
-    }
-
-    /**
-     * Returns the peer's endpoint.
-     *
-     * @return the endpoint, or {@code Optional.empty()} if none is configured
-     */
-    public Optional<InetEndpoint> getEndpoint() {
-        return endpoint;
-    }
-
-    /**
-     * Returns the peer's persistent keepalive.
-     *
-     * @return the persistent keepalive, or {@code Optional.empty()} if none is configured
-     */
-    public Optional<Integer> getPersistentKeepalive() {
-        return persistentKeepalive;
-    }
-
-    /**
-     * Returns the peer's pre-shared key.
-     *
-     * @return the pre-shared key, or {@code Optional.empty()} if none is configured
-     */
-    public Optional<Key> getPreSharedKey() {
-        return preSharedKey;
-    }
-
-    /**
-     * Returns the peer's public key.
-     *
-     * @return the public key
-     */
-    public Key getPublicKey() {
-        return publicKey;
-    }
-
-    @Override
-    public int hashCode() {
-        int hash = 1;
-        hash = 31 * hash + allowedIps.hashCode();
-        hash = 31 * hash + endpoint.hashCode();
-        hash = 31 * hash + persistentKeepalive.hashCode();
-        hash = 31 * hash + preSharedKey.hashCode();
-        hash = 31 * hash + publicKey.hashCode();
-        return hash;
-    }
-
-    /**
-     * Converts the {@code Peer} into a string suitable for debugging purposes. The {@code Peer} is
-     * identified by its public key and (if known) its endpoint.
-     *
-     * @return a concise single-line identifier for the {@code Peer}
-     */
-    @Override
-    public String toString() {
-        final StringBuilder sb = new StringBuilder("(Peer ");
-        sb.append(publicKey.toBase64());
-        endpoint.ifPresent(ep -> sb.append(" @").append(ep));
-        sb.append(')');
-        return sb.toString();
-    }
-
-    /**
-     * Converts the {@code Peer} into a string suitable for inclusion in a {@code wg-quick}
-     * configuration file.
-     *
-     * @return the {@code Peer} represented as a series of "Key = Value" lines
-     */
-    public String toWgQuickString() {
-        final StringBuilder sb = new StringBuilder();
-        if (!allowedIps.isEmpty())
-            sb.append("AllowedIPs = ").append(Attribute.join(allowedIps)).append('\n');
-        endpoint.ifPresent(ep -> sb.append("Endpoint = ").append(ep).append('\n'));
-        persistentKeepalive.ifPresent(pk -> sb.append("PersistentKeepalive = ").append(pk).append('\n'));
-        preSharedKey.ifPresent(psk -> sb.append("PreSharedKey = ").append(psk.toBase64()).append('\n'));
-        sb.append("PublicKey = ").append(publicKey.toBase64()).append('\n');
-        return sb.toString();
-    }
-
-    /**
-     * Serializes the {@code Peer} for use with the WireGuard cross-platform userspace API. Note
-     * that not all attributes are included in this representation.
-     *
-     * @return the {@code Peer} represented as a series of "key=value" lines
-     */
-    public String toWgUserspaceString() {
-        final StringBuilder sb = new StringBuilder();
-        // The order here is important: public_key signifies the beginning of a new peer.
-        sb.append("public_key=").append(publicKey.toHex()).append('\n');
-        for (final InetNetwork allowedIp : allowedIps)
-            sb.append("allowed_ip=").append(allowedIp).append('\n');
-        endpoint.flatMap(InetEndpoint::getResolved).ifPresent(ep -> sb.append("endpoint=").append(ep).append('\n'));
-        persistentKeepalive.ifPresent(pk -> sb.append("persistent_keepalive_interval=").append(pk).append('\n'));
-        preSharedKey.ifPresent(psk -> sb.append("preshared_key=").append(psk.toHex()).append('\n'));
-        return sb.toString();
-    }
-
-    @SuppressWarnings("UnusedReturnValue")
-    public static final class Builder {
-        // See wg(8)
-        private static final int MAX_PERSISTENT_KEEPALIVE = 65535;
-
-        // Defaults to an empty set.
-        private final Set<InetNetwork> allowedIps = new LinkedHashSet<>();
-        // Defaults to not present.
-        private Optional<InetEndpoint> endpoint = Optional.empty();
-        // Defaults to not present.
-        private Optional<Integer> persistentKeepalive = Optional.empty();
-        // Defaults to not present.
-        private Optional<Key> preSharedKey = Optional.empty();
-        // No default; must be provided before building.
-        @Nullable private Key publicKey;
-
-        public Builder addAllowedIp(final InetNetwork allowedIp) {
-            allowedIps.add(allowedIp);
-            return this;
-        }
-
-        public Builder addAllowedIps(final Collection<InetNetwork> allowedIps) {
-            this.allowedIps.addAll(allowedIps);
-            return this;
-        }
-
-        public Peer build() throws BadConfigException {
-            if (publicKey == null)
-                throw new BadConfigException(Section.PEER, Location.PUBLIC_KEY,
-                        Reason.MISSING_ATTRIBUTE, null);
-            return new Peer(this);
-        }
-
-        public Builder parseAllowedIPs(final CharSequence allowedIps) throws BadConfigException {
-            try {
-                for (final String allowedIp : Attribute.split(allowedIps))
-                    addAllowedIp(InetNetwork.parse(allowedIp));
-                return this;
-            } catch (final ParseException e) {
-                throw new BadConfigException(Section.PEER, Location.ALLOWED_IPS, e);
-            }
-        }
-
-        public Builder parseEndpoint(final String endpoint) throws BadConfigException {
-            try {
-                return setEndpoint(InetEndpoint.parse(endpoint));
-            } catch (final ParseException e) {
-                throw new BadConfigException(Section.PEER, Location.ENDPOINT, e);
-            }
-        }
-
-        public Builder parsePersistentKeepalive(final String persistentKeepalive)
-                throws BadConfigException {
-            try {
-                return setPersistentKeepalive(Integer.parseInt(persistentKeepalive));
-            } catch (final NumberFormatException e) {
-                throw new BadConfigException(Section.PEER, Location.PERSISTENT_KEEPALIVE,
-                        persistentKeepalive, e);
-            }
-        }
-
-        public Builder parsePreSharedKey(final String preSharedKey) throws BadConfigException {
-            try {
-                return setPreSharedKey(Key.fromBase64(preSharedKey));
-            } catch (final KeyFormatException e) {
-                throw new BadConfigException(Section.PEER, Location.PRE_SHARED_KEY, e);
-            }
-        }
-
-        public Builder parsePublicKey(final String publicKey) throws BadConfigException {
-            try {
-                return setPublicKey(Key.fromBase64(publicKey));
-            } catch (final KeyFormatException e) {
-                throw new BadConfigException(Section.PEER, Location.PUBLIC_KEY, e);
-            }
-        }
-
-        public Builder setEndpoint(final InetEndpoint endpoint) {
-            this.endpoint = Optional.of(endpoint);
-            return this;
-        }
-
-        public Builder setPersistentKeepalive(final int persistentKeepalive)
-                throws BadConfigException {
-            if (persistentKeepalive < 0 || persistentKeepalive > MAX_PERSISTENT_KEEPALIVE)
-                throw new BadConfigException(Section.PEER, Location.PERSISTENT_KEEPALIVE,
-                        Reason.INVALID_VALUE, String.valueOf(persistentKeepalive));
-            this.persistentKeepalive = persistentKeepalive == 0 ?
-                    Optional.empty() : Optional.of(persistentKeepalive);
-            return this;
-        }
-
-        public Builder setPreSharedKey(final Key preSharedKey) {
-            this.preSharedKey = Optional.of(preSharedKey);
-            return this;
-        }
-
-        public Builder setPublicKey(final Key publicKey) {
-            this.publicKey = publicKey;
-            return this;
-        }
-    }
-}
diff --git a/app/src/main/java/com/wireguard/crypto/Curve25519.java b/app/src/main/java/com/wireguard/crypto/Curve25519.java
deleted file mode 100644
index 5622fc5f..00000000
--- a/app/src/main/java/com/wireguard/crypto/Curve25519.java
+++ /dev/null
@@ -1,497 +0,0 @@
-/*
- * Copyright © 2016 Southern Storm Software, Pty Ltd.
- * Copyright © 2017-2019 WireGuard LLC. All Rights Reserved.
- * SPDX-License-Identifier: Apache-2.0
- */
-
-package com.wireguard.crypto;
-
-import androidx.annotation.Nullable;
-
-import java.util.Arrays;
-
-/**
- * Implementation of the Curve25519 elliptic curve algorithm.
- * <p>
- * This implementation was imported to WireGuard from noise-java:
- * https://github.com/rweather/noise-java
- * <p>
- * This implementation is based on that from arduinolibs:
- * https://github.com/rweather/arduinolibs
- * <p>
- * Differences in this version are due to using 26-bit limbs for the
- * representation instead of the 8/16/32-bit limbs in the original.
- * <p>
- * References: http://cr.yp.to/ecdh.html, RFC 7748
- */
-@SuppressWarnings({"MagicNumber", "NonConstantFieldWithUpperCaseName", "SuspiciousNameCombination"})
-public final class Curve25519 {
-    // Numbers modulo 2^255 - 19 are broken up into ten 26-bit words.
-    private static final int NUM_LIMBS_255BIT = 10;
-    private static final int NUM_LIMBS_510BIT = 20;
-
-    private final int[] A;
-    private final int[] AA;
-    private final int[] B;
-    private final int[] BB;
-    private final int[] C;
-    private final int[] CB;
-    private final int[] D;
-    private final int[] DA;
-    private final int[] E;
-    private final long[] t1;
-    private final int[] t2;
-    private final int[] x_1;
-    private final int[] x_2;
-    private final int[] x_3;
-    private final int[] z_2;
-    private final int[] z_3;
-
-    /**
-     * Constructs the temporary state holder for Curve25519 evaluation.
-     */
-    private Curve25519() {
-        // Allocate memory for all of the temporary variables we will need.
-        x_1 = new int[NUM_LIMBS_255BIT];
-        x_2 = new int[NUM_LIMBS_255BIT];
-        x_3 = new int[NUM_LIMBS_255BIT];
-        z_2 = new int[NUM_LIMBS_255BIT];
-        z_3 = new int[NUM_LIMBS_255BIT];
-        A = new int[NUM_LIMBS_255BIT];
-        B = new int[NUM_LIMBS_255BIT];
-        C = new int[NUM_LIMBS_255BIT];
-        D = new int[NUM_LIMBS_255BIT];
-        E = new int[NUM_LIMBS_255BIT];
-        AA = new int[NUM_LIMBS_255BIT];
-        BB = new int[NUM_LIMBS_255BIT];
-        DA = new int[NUM_LIMBS_255BIT];
-        CB = new int[NUM_LIMBS_255BIT];
-        t1 = new long[NUM_LIMBS_510BIT];
-        t2 = new int[NUM_LIMBS_510BIT];
-    }
-
-    /**
-     * Conditional swap of two values.
-     *
-     * @param select Set to 1 to swap, 0 to leave as-is.
-     * @param x      The first value.
-     * @param y      The second value.
-     */
-    private static void cswap(int select, final int[] x, final int[] y) {
-        select = -select;
-        for (int index = 0; index < NUM_LIMBS_255BIT; ++index) {
-            final int dummy = select & (x[index] ^ y[index]);
-            x[index] ^= dummy;
-            y[index] ^= dummy;
-        }
-    }
-
-    /**
-     * Evaluates the Curve25519 curve.
-     *
-     * @param result     Buffer to place the result of the evaluation into.
-     * @param offset     Offset into the result buffer.
-     * @param privateKey The private key to use in the evaluation.
-     * @param publicKey  The public key to use in the evaluation, or null
-     *                   if the base point of the curve should be used.
-     */
-    public static void eval(final byte[] result, final int offset,
-                            final byte[] privateKey, @Nullable final byte[] publicKey) {
-        final Curve25519 state = new Curve25519();
-        try {
-            // Unpack the public key value.  If null, use 9 as the base point.
-            Arrays.fill(state.x_1, 0);
-            if (publicKey != null) {
-                // Convert the input value from little-endian into 26-bit limbs.
-                for (int index = 0; index < 32; ++index) {
-                    final int bit = (index * 8) % 26;
-                    final int word = (index * 8) / 26;
-                    final int value = publicKey[index] & 0xFF;
-                    if (bit <= (26 - 8)) {
-                        state.x_1[word] |= value << bit;
-                    } else {
-                        state.x_1[word] |= value << bit;
-                        state.x_1[word] &= 0x03FFFFFF;
-                        state.x_1[word + 1] |= value >> (26 - bit);
-                    }
-                }
-
-                // Just in case, we reduce the number modulo 2^255 - 19 to
-                // make sure that it is in range of the field before we start.
-                // This eliminates values between 2^255 - 19 and 2^256 - 1.
-                state.reduceQuick(state.x_1);
-                state.reduceQuick(state.x_1);
-            } else {
-                state.x_1[0] = 9;
-            }
-
-            // Initialize the other temporary variables.
-            Arrays.fill(state.x_2, 0);            // x_2 = 1
-            state.x_2[0] = 1;
-            Arrays.fill(state.z_2, 0);            // z_2 = 0
-            System.arraycopy(state.x_1, 0, state.x_3, 0, state.x_1.length);  // x_3 = x_1
-            Arrays.fill(state.z_3, 0);            // z_3 = 1
-            state.z_3[0] = 1;
-
-            // Evaluate the curve for every bit of the private key.
-            state.evalCurve(privateKey);
-
-            // Compute x_2 * (z_2 ^ (p - 2)) where p = 2^255 - 19.
-            state.recip(state.z_3, state.z_2);
-            state.mul(state.x_2, state.x_2, state.z_3);
-
-            // Convert x_2 into little-endian in the result buffer.
-            for (int index = 0; index < 32; ++index) {
-                final int bit = (index * 8) % 26;
-                final int word = (index * 8) / 26;
-                if (bit <= (26 - 8))
-                    result[offset + index] = (byte) (state.x_2[word] >> bit);
-                else
-                    result[offset + index] = (byte) ((state.x_2[word] >> bit) | (state.x_2[word + 1] << (26 - bit)));
-            }
-        } finally {
-            // Clean up all temporary state before we exit.
-            state.destroy();
-        }
-    }
-
-    /**
-     * Subtracts two numbers modulo 2^255 - 19.
-     *
-     * @param result The result.
-     * @param x      The first number to subtract.
-     * @param y      The second number to subtract.
-     */
-    private static void sub(final int[] result, final int[] x, final int[] y) {
-        int index;
-        int borrow;
-
-        // Subtract y from x to generate the intermediate result.
-        borrow = 0;
-        for (index = 0; index < NUM_LIMBS_255BIT; ++index) {
-            borrow = x[index] - y[index] - ((borrow >> 26) & 0x01);
-            result[index] = borrow & 0x03FFFFFF;
-        }
-
-        // If we had a borrow, then the result has gone negative and we
-        // have to add 2^255 - 19 to the result to make it positive again.
-        // The top bits of "borrow" will be all 1's if there is a borrow
-        // or it will be all 0's if there was no borrow.  Easiest is to
-        // conditionally subtract 19 and then mask off the high bits.
-        borrow = result[0] - ((-((borrow >> 26) & 0x01)) & 19);
-        result[0] = borrow & 0x03FFFFFF;
-        for (index = 1; index < NUM_LIMBS_255BIT; ++index) {
-            borrow = result[index] - ((borrow >> 26) & 0x01);
-            result[index] = borrow & 0x03FFFFFF;
-        }
-        result[NUM_LIMBS_255BIT - 1] &= 0x001FFFFF;
-    }
-
-    /**
-     * Adds two numbers modulo 2^255 - 19.
-     *
-     * @param result The result.
-     * @param x      The first number to add.
-     * @param y      The second number to add.
-     */
-    private void add(final int[] result, final int[] x, final int[] y) {
-        int carry = x[0] + y[0];
-        result[0] = carry & 0x03FFFFFF;
-        for (int index = 1; index < NUM_LIMBS_255BIT; ++index) {
-            carry = (carry >> 26) + x[index] + y[index];
-            result[index] = carry & 0x03FFFFFF;
-        }
-        reduceQuick(result);
-    }
-
-    /**
-     * Destroy all sensitive data in this object.
-     */
-    private void destroy() {
-        // Destroy all temporary variables.
-        Arrays.fill(x_1, 0);
-        Arrays.fill(x_2, 0);
-        Arrays.fill(x_3, 0);
-        Arrays.fill(z_2, 0);
-        Arrays.fill(z_3, 0);
-        Arrays.fill(A, 0);
-        Arrays.fill(B, 0);
-        Arrays.fill(C, 0);
-        Arrays.fill(D, 0);
-        Arrays.fill(E, 0);
-        Arrays.fill(AA, 0);
-        Arrays.fill(BB, 0);
-        Arrays.fill(DA, 0);
-        Arrays.fill(CB, 0);
-        Arrays.fill(t1, 0L);
-        Arrays.fill(t2, 0);
-    }
-
-    /**
-     * Evaluates the curve for every bit in a secret key.
-     *
-     * @param s The 32-byte secret key.
-     */
-    private void evalCurve(final byte[] s) {
-        int sposn = 31;
-        int sbit = 6;
-        int svalue = s[sposn] | 0x40;
-        int swap = 0;
-
-        // Iterate over all 255 bits of "s" from the highest to the lowest.
-        // We ignore the high bit of the 256-bit representation of "s".
-        while (true) {
-            // Conditional swaps on entry to this bit but only if we
-            // didn't swap on the previous bit.
-            final int select = (svalue >> sbit) & 0x01;
-            swap ^= select;
-            cswap(swap, x_2, x_3);
-            cswap(swap, z_2, z_3);
-            swap = select;
-
-            // Evaluate the curve.
-            add(A, x_2, z_2);               // A = x_2 + z_2
-            square(AA, A);                  // AA = A^2
-            sub(B, x_2, z_2);               // B = x_2 - z_2
-            square(BB, B);                  // BB = B^2
-            sub(E, AA, BB);                 // E = AA - BB
-            add(C, x_3, z_3);               // C = x_3 + z_3
-            sub(D, x_3, z_3);               // D = x_3 - z_3
-            mul(DA, D, A);                  // DA = D * A
-            mul(CB, C, B);                  // CB = C * B
-            add(x_3, DA, CB);               // x_3 = (DA + CB)^2
-            square(x_3, x_3);
-            sub(z_3, DA, CB);               // z_3 = x_1 * (DA - CB)^2
-            square(z_3, z_3);
-            mul(z_3, z_3, x_1);
-            mul(x_2, AA, BB);               // x_2 = AA * BB
-            mulA24(z_2, E);                 // z_2 = E * (AA + a24 * E)
-            add(z_2, z_2, AA);
-            mul(z_2, z_2, E);
-
-            // Move onto the next lower bit of "s".
-            if (sbit > 0) {
-                --sbit;
-            } else if (sposn == 0) {
-                break;
-            } else if (sposn == 1) {
-                --sposn;
-                svalue = s[sposn] & 0xF8;
-                sbit = 7;
-            } else {
-                --sposn;
-                svalue = s[sposn];
-                sbit = 7;
-            }
-        }
-
-        // Final conditional swaps.
-        cswap(swap, x_2, x_3);
-        cswap(swap, z_2, z_3);
-    }
-
-    /**
-     * Multiplies two numbers modulo 2^255 - 19.
-     *
-     * @param result The result.
-     * @param x      The first number to multiply.
-     * @param y      The second number to multiply.
-     */
-    private void mul(final int[] result, final int[] x, final int[] y) {
-        // Multiply the two numbers to create the intermediate result.
-        long v = x[0];
-        for (int i = 0; i < NUM_LIMBS_255BIT; ++i) {
-            t1[i] = v * y[i];
-        }
-        for (int i = 1; i < NUM_LIMBS_255BIT; ++i) {
-            v = x[i];
-            for (int j = 0; j < (NUM_LIMBS_255BIT - 1); ++j) {
-                t1[i + j] += v * y[j];
-            }
-            t1[i + NUM_LIMBS_255BIT - 1] = v * y[NUM_LIMBS_255BIT - 1];
-        }
-
-        // Propagate carries and convert back into 26-bit words.
-        v = t1[0];
-        t2[0] = ((int) v) & 0x03FFFFFF;
-        for (int i = 1; i < NUM_LIMBS_510BIT; ++i) {
-            v = (v >> 26) + t1[i];
-            t2[i] = ((int) v) & 0x03FFFFFF;
-        }
-
-        // Reduce the result modulo 2^255 - 19.
-        reduce(result, t2, NUM_LIMBS_255BIT);
-    }
-
-    /**
-     * Multiplies a number by the a24 constant, modulo 2^255 - 19.
-     *
-     * @param result The result.
-     * @param x      The number to multiply by a24.
-     */
-    private void mulA24(final int[] result, final int[] x) {
-        final long a24 = 121665;
-        long carry = 0;
-        for (int index = 0; index < NUM_LIMBS_255BIT; ++index) {
-            carry += a24 * x[index];
-            t2[index] = ((int) carry) & 0x03FFFFFF;
-            carry >>= 26;
-        }
-        t2[NUM_LIMBS_255BIT] = ((int) carry) & 0x03FFFFFF;
-        reduce(result, t2, 1);
-    }
-
-    /**
-     * Raise x to the power of (2^250 - 1).
-     *
-     * @param result The result.  Must not overlap with x.
-     * @param x      The argument.
-     */
-    private void pow250(final int[] result, final int[] x) {
-        // The big-endian hexadecimal expansion of (2^250 - 1) is:
-        // 03FFFFFF FFFFFFFF FFFFFFFF FFFFFFFF FFFFFFFF FFFFFFFF FFFFFFFF FFFFFFFF
-        //
-        // The naive implementation needs to do 2 multiplications per 1 bit and
-        // 1 multiplication per 0 bit.  We can improve upon this by creating a
-        // pattern 0000000001 ... 0000000001.  If we square and multiply the
-        // pattern by itself we can turn the pattern into the partial results
-        // 0000000011 ... 0000000011, 0000000111 ... 0000000111, etc.
-        // This averages out to about 1.1 multiplications per 1 bit instead of 2.
-
-        // Build a pattern of 250 bits in length of repeated copies of 0000000001.
-        square(A, x);
-        for (int j = 0; j < 9; ++j)
-            square(A, A);
-        mul(result, A, x);
-        for (int i = 0; i < 23; ++i) {
-            for (int j = 0; j < 10; ++j)
-                square(A, A);
-            mul(result, result, A);
-        }
-
-        // Multiply bit-shifted versions of the 0000000001 pattern into
-        // the result to "fill in" the gaps in the pattern.
-        square(A, result);
-        mul(result, result, A);
-        for (int j = 0; j < 8; ++j) {
-            square(A, A);
-            mul(result, result, A);
-        }
-    }
-
-    /**
-     * Computes the reciprocal of a number modulo 2^255 - 19.
-     *
-     * @param result The result.  Must not overlap with x.
-     * @param x      The argument.
-     */
-    private void recip(final int[] result, final int[] x) {
-        // The reciprocal is the same as x ^ (p - 2) where p = 2^255 - 19.
-        // The big-endian hexadecimal expansion of (p - 2) is:
-        // 7FFFFFFF FFFFFFFF FFFFFFFF FFFFFFFF FFFFFFFF FFFFFFFF FFFFFFFF FFFFFFEB
-        // Start with the 250 upper bits of the expansion of (p - 2).
-        pow250(result, x);
-
-        // Deal with the 5 lowest bits of (p - 2), 01011, from highest to lowest.
-        square(result, result);
-        square(result, result);
-        mul(result, result, x);
-        square(result, result);
-        square(result, result);
-        mul(result, result, x);
-        square(result, result);
-        mul(result, result, x);
-    }
-
-    /**
-     * Reduce a number modulo 2^255 - 19.
-     *
-     * @param result The result.
-     * @param x      The value to be reduced.  This array will be
-     *               modified during the reduction.
-     * @param size   The number of limbs in the high order half of x.
-     */
-    private void reduce(final int[] result, final int[] x, final int size) {
-        // Calculate (x mod 2^255) + ((x / 2^255) * 19) which will
-        // either produce the answer we want or it will produce a
-        // value of the form "answer + j * (2^255 - 19)".  There are
-        // 5 left-over bits in the top-most limb of the bottom half.
-        int carry = 0;
-        int limb = x[NUM_LIMBS_255BIT - 1] >> 21;
-        x[NUM_LIMBS_255BIT - 1] &= 0x001FFFFF;
-        for (int index = 0; index < size; ++index) {
-            limb += x[NUM_LIMBS_255BIT + index] << 5;
-            carry += (limb & 0x03FFFFFF) * 19 + x[index];
-            x[index] = carry & 0x03FFFFFF;
-            limb >>= 26;
-            carry >>= 26;
-        }
-        if (size < NUM_LIMBS_255BIT) {
-            // The high order half of the number is short; e.g. for mulA24().
-            // Propagate the carry through the rest of the low order part.
-            for (int index = size; index < NUM_LIMBS_255BIT; ++index) {
-                carry += x[index];
-                x[index] = carry & 0x03FFFFFF;
-                carry >>= 26;
-            }
-        }
-
-        // The "j" value may still be too large due to the final carry-out.
-        // We must repeat the reduction.  If we already have the answer,
-        // then this won't do any harm but we must still do the calculation
-        // to preserve the overall timing.  The "j" value will be between
-        // 0 and 19, which means that the carry we care about is in the
-        // top 5 bits of the highest limb of the bottom half.
-        carry = (x[NUM_LIMBS_255BIT - 1] >> 21) * 19;
-        x[NUM_LIMBS_255BIT - 1] &= 0x001FFFFF;
-        for (int index = 0; index < NUM_LIMBS_255BIT; ++index) {
-            carry += x[index];
-            result[index] = carry & 0x03FFFFFF;
-            carry >>= 26;
-        }
-
-        // At this point "x" will either be the answer or it will be the
-        // answer plus (2^255 - 19).  Perform a trial subtraction to
-        // complete the reduction process.
-        reduceQuick(result);
-    }
-
-    /**
-     * Reduces a number modulo 2^255 - 19 where it is known that the
-     * number can be reduced with only 1 trial subtraction.
-     *
-     * @param x The number to reduce, and the result.
-     */
-    private void reduceQuick(final int[] x) {
-        // Perform a trial subtraction of (2^255 - 19) from "x" which is
-        // equivalent to adding 19 and subtracting 2^255.  We add 19 here;
-        // the subtraction of 2^255 occurs in the next step.
-        int carry = 19;
-        for (int index = 0; index < NUM_LIMBS_255BIT; ++index) {
-            carry += x[index];
-            t2[index] = carry & 0x03FFFFFF;
-            carry >>= 26;
-        }
-
-        // If there was a borrow, then the original "x" is the correct answer.
-        // If there was no borrow, then "t2" is the correct answer.  Select the
-        // correct answer but do it in a way that instruction timing will not
-        // reveal which value was selected.  Borrow will occur if bit 21 of
-        // "t2" is zero.  Turn the bit into a selection mask.
-        final int mask = -((t2[NUM_LIMBS_255BIT - 1] >> 21) & 0x01);
-        final int nmask = ~mask;
-        t2[NUM_LIMBS_255BIT - 1] &= 0x001FFFFF;
-        for (int index = 0; index < NUM_LIMBS_255BIT; ++index)
-            x[index] = (x[index] & nmask) | (t2[index] & mask);
-    }
-
-    /**
-     * Squares a number modulo 2^255 - 19.
-     *
-     * @param result The result.
-     * @param x      The number to square.
-     */
-    private void square(final int[] result, final int[] x) {
-        mul(result, x, x);
-    }
-}
diff --git a/app/src/main/java/com/wireguard/crypto/Key.java b/app/src/main/java/com/wireguard/crypto/Key.java
deleted file mode 100644
index 6648a5f3..00000000
--- a/app/src/main/java/com/wireguard/crypto/Key.java
+++ /dev/null
@@ -1,288 +0,0 @@
-/*
- * Copyright © 2017-2019 WireGuard LLC. All Rights Reserved.
- * SPDX-License-Identifier: Apache-2.0
- */
-
-package com.wireguard.crypto;
-
-import com.wireguard.crypto.KeyFormatException.Type;
-
-import java.security.MessageDigest;
-import java.security.SecureRandom;
-import java.util.Arrays;
-
-/**
- * Represents a WireGuard public or private key. This class uses specialized constant-time base64
- * and hexadecimal codec implementations that resist side-channel attacks.
- * <p>
- * Instances of this class are immutable.
- */
-@SuppressWarnings("MagicNumber")
-public final class Key {
-    private final byte[] key;
-
-    /**
-     * Constructs an object encapsulating the supplied key.
-     *
-     * @param key an array of bytes containing a binary key. Callers of this constructor are
-     *            responsible for ensuring that the array is of the correct length.
-     */
-    private Key(final byte[] key) {
-        // Defensively copy to ensure immutability.
-        this.key = Arrays.copyOf(key, key.length);
-    }
-
-    /**
-     * Decodes a single 4-character base64 chunk to an integer in constant time.
-     *
-     * @param src       an array of at least 4 characters in base64 format
-     * @param srcOffset the offset of the beginning of the chunk in {@code src}
-     * @return the decoded 3-byte integer, or some arbitrary integer value if the input was not
-     * valid base64
-     */
-    private static int decodeBase64(final char[] src, final int srcOffset) {
-        int val = 0;
-        for (int i = 0; i < 4; ++i) {
-            final char c = src[i + srcOffset];
-            val |= (-1
-                    + ((((('A' - 1) - c) & (c - ('Z' + 1))) >>> 8) & (c - 64))
-                    + ((((('a' - 1) - c) & (c - ('z' + 1))) >>> 8) & (c - 70))
-                    + ((((('0' - 1) - c) & (c - ('9' + 1))) >>> 8) & (c + 5))
-                    + ((((('+' - 1) - c) & (c - ('+' + 1))) >>> 8) & 63)
-                    + ((((('/' - 1) - c) & (c - ('/' + 1))) >>> 8) & 64)
-            ) << (18 - 6 * i);
-        }
-        return val;
-    }
-
-    /**
-     * Encodes a single 4-character base64 chunk from 3 consecutive bytes in constant time.
-     *
-     * @param src        an array of at least 3 bytes
-     * @param srcOffset  the offset of the beginning of the chunk in {@code src}
-     * @param dest       an array of at least 4 characters
-     * @param destOffset the offset of the beginning of the chunk in {@code dest}
-     */
-    private static void encodeBase64(final byte[] src, final int srcOffset,
-                                     final char[] dest, final int destOffset) {
-        final byte[] input = {
-                (byte) ((src[srcOffset] >>> 2) & 63),
-                (byte) ((src[srcOffset] << 4 | ((src[1 + srcOffset] & 0xff) >>> 4)) & 63),
-                (byte) ((src[1 + srcOffset] << 2 | ((src[2 + srcOffset] & 0xff) >>> 6)) & 63),
-                (byte) ((src[2 + srcOffset]) & 63),
-        };
-        for (int i = 0; i < 4; ++i) {
-            dest[i + destOffset] = (char) (input[i] + 'A'
-                    + (((25 - input[i]) >>> 8) & 6)
-                    - (((51 - input[i]) >>> 8) & 75)
-                    - (((61 - input[i]) >>> 8) & 15)
-                    + (((62 - input[i]) >>> 8) & 3));
-        }
-    }
-
-    /**
-     * Decodes a WireGuard public or private key from its base64 string representation. This
-     * function throws a {@link KeyFormatException} if the source string is not well-formed.
-     *
-     * @param str the base64 string representation of a WireGuard key
-     * @return the decoded key encapsulated in an immutable container
-     */
-    public static Key fromBase64(final String str) throws KeyFormatException {
-        final char[] input = str.toCharArray();
-        if (input.length != Format.BASE64.length || input[Format.BASE64.length - 1] != '=')
-            throw new KeyFormatException(Format.BASE64, Type.LENGTH);
-        final byte[] key = new byte[Format.BINARY.length];
-        int i;
-        int ret = 0;
-        for (i = 0; i < key.length / 3; ++i) {
-            final int val = decodeBase64(input, i * 4);
-            ret |= val >>> 31;
-            key[i * 3] = (byte) ((val >>> 16) & 0xff);
-            key[i * 3 + 1] = (byte) ((val >>> 8) & 0xff);
-            key[i * 3 + 2] = (byte) (val & 0xff);
-        }
-        final char[] endSegment = {
-                input[i * 4],
-                input[i * 4 + 1],
-                input[i * 4 + 2],
-                'A',
-        };
-        final int val = decodeBase64(endSegment, 0);
-        ret |= (val >>> 31) | (val & 0xff);
-        key[i * 3] = (byte) ((val >>> 16) & 0xff);
-        key[i * 3 + 1] = (byte) ((val >>> 8) & 0xff);
-
-        if (ret != 0)
-            throw new KeyFormatException(Format.BASE64, Type.CONTENTS);
-        return new Key(key);
-    }
-
-    /**
-     * Wraps a WireGuard public or private key in an immutable container. This function throws a
-     * {@link KeyFormatException} if the source data is not the correct length.
-     *
-     * @param bytes an array of bytes containing a WireGuard key in binary format
-     * @return the key encapsulated in an immutable container
-     */
-    public static Key fromBytes(final byte[] bytes) throws KeyFormatException {
-        if (bytes.length != Format.BINARY.length)
-            throw new KeyFormatException(Format.BINARY, Type.LENGTH);
-        return new Key(bytes);
-    }
-
-    /**
-     * Decodes a WireGuard public or private key from its hexadecimal string representation. This
-     * function throws a {@link KeyFormatException} if the source string is not well-formed.
-     *
-     * @param str the hexadecimal string representation of a WireGuard key
-     * @return the decoded key encapsulated in an immutable container
-     */
-    public static Key fromHex(final String str) throws KeyFormatException {
-        final char[] input = str.toCharArray();
-        if (input.length != Format.HEX.length)
-            throw new KeyFormatException(Format.HEX, Type.LENGTH);
-        final byte[] key = new byte[Format.BINARY.length];
-        int ret = 0;
-        for (int i = 0; i < key.length; ++i) {
-            int c;
-            int cNum;
-            int cNum0;
-            int cAlpha;
-            int cAlpha0;
-            int cVal;
-            final int cAcc;
-
-            c = input[i * 2];
-            cNum = c ^ 48;
-            cNum0 = ((cNum - 10) >>> 8) & 0xff;
-            cAlpha = (c & ~32) - 55;
-            cAlpha0 = (((cAlpha - 10) ^ (cAlpha - 16)) >>> 8) & 0xff;
-            ret |= ((cNum0 | cAlpha0) - 1) >>> 8;
-            cVal = (cNum0 & cNum) | (cAlpha0 & cAlpha);
-            cAcc = cVal * 16;
-
-            c = input[i * 2 + 1];
-            cNum = c ^ 48;
-            cNum0 = ((cNum - 10) >>> 8) & 0xff;
-            cAlpha = (c & ~32) - 55;
-            cAlpha0 = (((cAlpha - 10) ^ (cAlpha - 16)) >>> 8) & 0xff;
-            ret |= ((cNum0 | cAlpha0) - 1) >>> 8;
-            cVal = (cNum0 & cNum) | (cAlpha0 & cAlpha);
-            key[i] = (byte) (cAcc | cVal);
-        }
-        if (ret != 0)
-            throw new KeyFormatException(Format.HEX, Type.CONTENTS);
-        return new Key(key);
-    }
-
-    /**
-     * Generates a private key using the system's {@link SecureRandom} number generator.
-     *
-     * @return a well-formed random private key
-     */
-    static Key generatePrivateKey() {
-        final SecureRandom secureRandom = new SecureRandom();
-        final byte[] privateKey = new byte[Format.BINARY.getLength()];
-        secureRandom.nextBytes(privateKey);
-        privateKey[0] &= 248;
-        privateKey[31] &= 127;
-        privateKey[31] |= 64;
-        return new Key(privateKey);
-    }
-
-    /**
-     * Generates a public key from an existing private key.
-     *
-     * @param privateKey a private key
-     * @return a well-formed public key that corresponds to the supplied private key
-     */
-    static Key generatePublicKey(final Key privateKey) {
-        final byte[] publicKey = new byte[Format.BINARY.getLength()];
-        Curve25519.eval(publicKey, 0, privateKey.getBytes(), null);
-        return new Key(publicKey);
-    }
-
-    /**
-     * Returns the key as an array of bytes.
-     *
-     * @return an array of bytes containing the raw binary key
-     */
-    public byte[] getBytes() {
-        // Defensively copy to ensure immutability.
-        return Arrays.copyOf(key, key.length);
-    }
-
-    /**
-     * Encodes the key to base64.
-     *
-     * @return a string containing the encoded key
-     */
-    public String toBase64() {
-        final char[] output = new char[Format.BASE64.length];
-        int i;
-        for (i = 0; i < key.length / 3; ++i)
-            encodeBase64(key, i * 3, output, i * 4);
-        final byte[] endSegment = {
-                key[i * 3],
-                key[i * 3 + 1],
-                0,
-        };
-        encodeBase64(endSegment, 0, output, i * 4);
-        output[Format.BASE64.length - 1] = '=';
-        return new String(output);
-    }
-
-    /**
-     * Encodes the key to hexadecimal ASCII characters.
-     *
-     * @return a string containing the encoded key
-     */
-    public String toHex() {
-        final char[] output = new char[Format.HEX.length];
-        for (int i = 0; i < key.length; ++i) {
-            output[i * 2] = (char) (87 + (key[i] >> 4 & 0xf)
-                    + ((((key[i] >> 4 & 0xf) - 10) >> 8) & ~38));
-            output[i * 2 + 1] = (char) (87 + (key[i] & 0xf)
-                    + ((((key[i] & 0xf) - 10) >> 8) & ~38));
-        }
-        return new String(output);
-    }
-
-    @Override
-    public int hashCode() {
-        int ret = 0;
-        for (int i = 0; i < key.length / 4; ++i)
-            ret ^= (key[i * 4 + 0] >> 0) + (key[i * 4 + 1] >> 8) + (key[i * 4 + 2] >> 16) + (key[i * 4 + 3] >> 24);
-        return ret;
-    }
-
-    @Override
-    public boolean equals(final Object obj) {
-        if (obj == this)
-            return true;
-        if (obj == null || obj.getClass() != getClass())
-            return false;
-        final Key other = (Key) obj;
-        return MessageDigest.isEqual(key, other.key);
-    }
-
-    /**
-     * The supported formats for encoding a WireGuard key.
-     */
-    public enum Format {
-        BASE64(44),
-        BINARY(32),
-        HEX(64);
-
-        private final int length;
-
-        Format(final int length) {
-            this.length = length;
-        }
-
-        public int getLength() {
-            return length;
-        }
-    }
-
-}
diff --git a/app/src/main/java/com/wireguard/crypto/KeyFormatException.java b/app/src/main/java/com/wireguard/crypto/KeyFormatException.java
deleted file mode 100644
index 5818b4d4..00000000
--- a/app/src/main/java/com/wireguard/crypto/KeyFormatException.java
+++ /dev/null
@@ -1,34 +0,0 @@
-/*
- * Copyright © 2018-2019 WireGuard LLC. All Rights Reserved.
- * SPDX-License-Identifier: Apache-2.0
- */
-
-package com.wireguard.crypto;
-
-/**
- * An exception thrown when attempting to parse an invalid key (too short, too long, or byte
- * data inappropriate for the format). The format being parsed can be accessed with the
- * {@link #getFormat} method.
- */
-public final class KeyFormatException extends Exception {
-    private final Key.Format format;
-    private final Type type;
-
-    KeyFormatException(final Key.Format format, final Type type) {
-        this.format = format;
-        this.type = type;
-    }
-
-    public Key.Format getFormat() {
-        return format;
-    }
-
-    public Type getType() {
-        return type;
-    }
-
-    public enum Type {
-        CONTENTS,
-        LENGTH
-    }
-}
diff --git a/app/src/main/java/com/wireguard/crypto/KeyPair.java b/app/src/main/java/com/wireguard/crypto/KeyPair.java
deleted file mode 100644
index f8238e91..00000000
--- a/app/src/main/java/com/wireguard/crypto/KeyPair.java
+++ /dev/null
@@ -1,51 +0,0 @@
-/*
- * Copyright © 2017-2019 WireGuard LLC. All Rights Reserved.
- * SPDX-License-Identifier: Apache-2.0
- */
-
-package com.wireguard.crypto;
-
-/**
- * Represents a Curve25519 key pair as used by WireGuard.
- * <p>
- * Instances of this class are immutable.
- */
-public class KeyPair {
-    private final Key privateKey;
-    private final Key publicKey;
-
-    /**
-     * Creates a key pair using a newly-generated private key.
-     */
-    public KeyPair() {
-        this(Key.generatePrivateKey());
-    }
-
-    /**
-     * Creates a key pair using an existing private key.
-     *
-     * @param privateKey a private key, used to derive the public key
-     */
-    public KeyPair(final Key privateKey) {
-        this.privateKey = privateKey;
-        publicKey = Key.generatePublicKey(privateKey);
-    }
-
-    /**
-     * Returns the private key from the key pair.
-     *
-     * @return the private key
-     */
-    public Key getPrivateKey() {
-        return privateKey;
-    }
-
-    /**
-     * Returns the public key from the key pair.
-     *
-     * @return the public key
-     */
-    public Key getPublicKey() {
-        return publicKey;
-    }
-}
diff --git a/app/src/main/java/com/wireguard/util/NonNullForAll.java b/app/src/main/java/com/wireguard/util/NonNullForAll.java
deleted file mode 100644
index f179fa49..00000000
--- a/app/src/main/java/com/wireguard/util/NonNullForAll.java
+++ /dev/null
@@ -1,26 +0,0 @@
-/*
- * Copyright © 2017-2019 WireGuard LLC. All Rights Reserved.
- * SPDX-License-Identifier: Apache-2.0
- */
-
-package com.wireguard.util;
-
-import java.lang.annotation.Documented;
-import java.lang.annotation.ElementType;
-import java.lang.annotation.Retention;
-import java.lang.annotation.RetentionPolicy;
-
-import javax.annotation.Nonnull;
-import javax.annotation.meta.TypeQualifierDefault;
-
-/**
- * This annotation can be applied to a package, class or method to indicate that all
- * class fields and method parameters and return values in that element are nonnull
- * by default unless overridden.
- */
-@Documented
-@Nonnull
-@TypeQualifierDefault({ElementType.FIELD, ElementType.METHOD, ElementType.PARAMETER})
-@Retention(RetentionPolicy.RUNTIME)
-public @interface NonNullForAll {
-}