add UI for certificate trust

app/src/main/java/im/conversations/android/ui/NavControllers.java

@@ -1,8 +1,8 @@
 package im.conversations.android.ui;
 
 import androidx.annotation.IdRes;
-import androidx.appcompat.app.AppCompatActivity;
 import androidx.fragment.app.Fragment;
+import androidx.fragment.app.FragmentActivity;
 import androidx.fragment.app.FragmentManager;
 import androidx.navigation.NavController;
 import androidx.navigation.fragment.NavHostFragment;
@@ -12,7 +12,7 @@ public final class NavControllers {
     private NavControllers() {}
 
     public static NavController findNavController(
-            final AppCompatActivity activity, @IdRes int fragmentId) {
+            final FragmentActivity activity, @IdRes int fragmentId) {
         final FragmentManager fragmentManager = activity.getSupportFragmentManager();
         final Fragment fragment = fragmentManager.findFragmentById(fragmentId);
         if (fragment instanceof NavHostFragment) {

app/src/main/java/im/conversations/android/ui/activity/SetupActivity.java

@@ -55,6 +55,13 @@ public class SetupActivity extends BaseActivity {
                 case ENTER_HOSTNAME:
                     navController.navigate(SetupNavigationDirections.enterHostname());
                     break;
+                case TRUST_CERTIFICATE:
+                    final var currentDestination = navController.getCurrentDestination();
+                    if (currentDestination == null
+                            || currentDestination.getId() != R.id.certificate) {
+                        navController.navigate(SetupNavigationDirections.trustCertificate());
+                    }
+                    break;
                 case DONE:
                     startActivity(new Intent(this, MainActivity.class));
                     finish();

app/src/main/java/im/conversations/android/ui/fragment/setup/TrustCertificateFragment.java

@@ -0,0 +1,40 @@
+package im.conversations.android.ui.fragment.setup;
+
+import android.os.Bundle;
+import android.view.LayoutInflater;
+import android.view.View;
+import android.view.ViewGroup;
+import androidx.activity.OnBackPressedCallback;
+import androidx.annotation.NonNull;
+import androidx.databinding.DataBindingUtil;
+import im.conversations.android.R;
+import im.conversations.android.databinding.FragmentTrustCertificateBinding;
+import im.conversations.android.ui.NavControllers;
+
+public class TrustCertificateFragment extends AbstractSetupFragment {
+
+    @Override
+    public View onCreateView(
+            @NonNull LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
+        super.onCreateView(inflater, container, savedInstanceState);
+        FragmentTrustCertificateBinding binding =
+                DataBindingUtil.inflate(
+                        inflater, R.layout.fragment_trust_certificate, container, false);
+        binding.setSetupViewModel(setupViewModel);
+        binding.setLifecycleOwner(getViewLifecycleOwner());
+        requireActivity()
+                .getOnBackPressedDispatcher()
+                .addCallback(
+                        getViewLifecycleOwner(),
+                        new OnBackPressedCallback(true) {
+                            @Override
+                            public void handleOnBackPressed() {
+                                setupViewModel.rejectTrustDecision();
+                                NavControllers.findNavController(
+                                                requireActivity(), R.id.nav_host_fragment)
+                                        .navigateUp();
+                            }
+                        });
+        return binding.getRoot();
+    }
+}

app/src/main/java/im/conversations/android/ui/model/SetupViewModel.java

@@ -26,8 +26,11 @@ import im.conversations.android.xmpp.ConnectionPool;
 import im.conversations.android.xmpp.ConnectionState;
 import im.conversations.android.xmpp.XmppConnection;
 import im.conversations.android.xmpp.manager.TrustManager;
+import java.nio.ByteBuffer;
 import java.util.Arrays;
+import java.util.HashMap;
 import java.util.Locale;
+import java.util.concurrent.CancellationException;
 import java.util.function.Function;
 import org.jetbrains.annotations.NotNull;
 import org.jxmpp.jid.BareJid;
@@ -56,13 +59,24 @@ public class SetupViewModel extends AndroidViewModel {
     private final MutableLiveData<Event<Target>> redirection = new MutableLiveData<>();
 
     private final MutableLiveData<TrustDecision> trustDecision = new MutableLiveData<>();
+    private final HashMap<ByteBuffer, Boolean> trustDecisions = new HashMap<>();
 
     private final Function<byte[], ListenableFuture<Boolean>> trustDecisionCallback =
             fingerprint -> {
+                final var decision = this.trustDecisions.get(ByteBuffer.wrap(fingerprint));
+                if (decision != null) {
+                    LOGGER.info("Using previous trust decision ({})", decision);
+                    return Futures.immediateFuture(decision);
+                }
+                LOGGER.info("Trust decision arrived in UI");
                 final SettableFuture<Boolean> settableFuture = SettableFuture.create();
                 final var trustDecision = new TrustDecision(fingerprint, settableFuture);
-                LOGGER.debug("posting trust decision");
+                final var currentOperation = this.currentOperation;
+                if (currentOperation != null) {
+                    currentOperation.cancel(false);
+                }
                 this.trustDecision.postValue(trustDecision);
+                this.redirection.postValue(new Event<>(Target.TRUST_CERTIFICATE));
                 return settableFuture;
             };
 
@@ -143,7 +157,7 @@ public class SetupViewModel extends AndroidViewModel {
             this.xmppAddressError.postValue(getApplication().getString(R.string.invalid_jid));
             return true;
         }
-
+        this.trustDecisions.clear();
         if (account != null) {
             if (account.address.equals(address)) {
                 this.accountRepository.reconnect(account);
@@ -167,6 +181,51 @@ public class SetupViewModel extends AndroidViewModel {
         return true;
     }
 
+    public boolean trustCertificate() {
+        final var trustDecision = this.trustDecision.getValue();
+        final var account = this.account;
+        if (trustDecision == null || account == null) {
+            // TODO navigate back to sign in or show error?
+            return true;
+        }
+        LOGGER.info(
+                "trying to commit trust for fingerprint {}",
+                TrustManager.fingerprint(trustDecision.fingerprint));
+        // in case the UI interface hook gets called again before this gets written to DB
+        this.trustDecisions.put(ByteBuffer.wrap(trustDecision.fingerprint), true);
+        if (trustDecision.decision.isDone()) {
+            ConnectionPool.getInstance(getApplication()).reconnect(account);
+            LOGGER.info("it was already done. we should reconnect");
+        }
+        trustDecision.decision.set(true);
+        decideNextStep(Target.TRUST_CERTIFICATE, account);
+        return true;
+    }
+
+    public void rejectTrustDecision() {
+        final var trustDecision = this.trustDecision.getValue();
+        if (trustDecision == null) {
+            return;
+        }
+        LOGGER.info(
+                "Rejecting trust decision for {}",
+                TrustManager.fingerprint(trustDecision.fingerprint));
+        trustDecision.decision.set(false);
+        this.trustDecisions.put(ByteBuffer.wrap(trustDecision.fingerprint), false);
+    }
+
+    public LiveData<String> getFingerprint() {
+        return Transformations.map(
+                this.trustDecision,
+                td -> {
+                    if (td == null) {
+                        return null;
+                    } else {
+                        return TrustManager.fingerprint(td.fingerprint, 8);
+                    }
+                });
+    }
+
     private void createAccount(final BareJid address) {
 
         // if the user hasn't entered anything we want this to be null so we don't store credentials
@@ -229,6 +288,8 @@ public class SetupViewModel extends AndroidViewModel {
         final var optionalTrustManager = getTrustManager();
         if (optionalTrustManager.isPresent()) {
             optionalTrustManager.get().removeUserInterfaceCallback(this.trustDecisionCallback);
+        } else {
+            LOGGER.warn("No trust manager found");
         }
     }
 
@@ -243,6 +304,7 @@ public class SetupViewModel extends AndroidViewModel {
                     public void onSuccess(final XmppConnection result) {
                         // TODO only when configured for loginAndBind
                         LOGGER.info("Account setup successful");
+                        unregisterTrustDecisionCallback();
                         SetupViewModel.this.account = null;
                         redirect(Target.DONE);
                     }
@@ -250,6 +312,10 @@ public class SetupViewModel extends AndroidViewModel {
                     @Override
                     public void onFailure(@NonNull final Throwable throwable) {
                         loading.postValue(false);
+                        if (throwable instanceof CancellationException) {
+                            LOGGER.info("connection future was cancelled");
+                            return;
+                        }
                         if (throwable instanceof ConnectionException) {
                             decideNextStep(current, ((ConnectionException) throwable));
                         } else {
@@ -317,6 +383,7 @@ public class SetupViewModel extends AndroidViewModel {
             this.portError.postValue(getApplication().getString(R.string.invalid));
             return true;
         }
+        this.trustDecisions.clear();
         final boolean directTls = Boolean.FALSE.equals(this.opportunisticTls.getValue());
         final var connection = new Connection(hostname, port, directTls);
         final var setConnectionFuture =
@@ -388,15 +455,19 @@ public class SetupViewModel extends AndroidViewModel {
         return this.redirection;
     }
 
+    @Override
     public void onCleared() {
-        super.onCleared();
+        LOGGER.info("Clearing view model");
         this.unregisterTrustDecisionCallback();
+        super.onCleared();
     }
 
     public enum Target {
         ENTER_ADDRESS,
         ENTER_PASSWORD,
         ENTER_HOSTNAME,
+
+        TRUST_CERTIFICATE,
         DONE
     }
 

app/src/main/java/im/conversations/android/util/PendingItem.java

@@ -29,7 +29,7 @@
 
 package im.conversations.android.util;
 
-import java.util.function.Supplier;
+import java.util.function.Function;
 
 public class PendingItem<T> {
 
@@ -49,10 +49,9 @@ public class PendingItem<T> {
         return item;
     }
 
-    public synchronized T peekOrCreate(final Supplier<T> supplier) {
+    public synchronized T peekOrSwap(final Function<T, T> swap) {
-        if (this.item == null) {
+        final T item = this.item;
-            this.item = supplier.get();
+        this.item = swap.apply(item);
-        }
         return this.item;
     }
 

app/src/main/java/im/conversations/android/xmpp/XmppConnection.java

@@ -1882,7 +1882,14 @@ public class XmppConnection implements Runnable {
             } else if (Arrays.asList(ConnectionState.OFFLINE, ConnectionState.CONNECTING)
                             .contains(state)
                     || waitOnError) {
-                return this.connectedFuture.peekOrCreate(SettableFuture::create);
+                return this.connectedFuture.peekOrSwap(
+                        f -> {
+                            if (f == null || f.isDone()) {
+                                return SettableFuture.create();
+                            } else {
+                                return f;
+                            }
+                        });
             } else {
                 return Futures.immediateFailedFuture(new ConnectionException(state));
             }

app/src/main/java/im/conversations/android/xmpp/manager/TrustManager.java

@@ -68,6 +68,7 @@ public class TrustManager extends AbstractManager implements X509TrustManager {
         try {
             decision = Boolean.TRUE.equals(futureDecision.get(10, TimeUnit.SECONDS));
         } catch (final ExecutionException | InterruptedException | TimeoutException e) {
+            futureDecision.cancel(true);
             throw new CertificateException(
                     "Timeout waiting for user response", Throwables.getRootCause(e));
         }
@@ -97,8 +98,17 @@ public class TrustManager extends AbstractManager implements X509TrustManager {
     }
 
     public static String fingerprint(final byte[] bytes) {
-        return Joiner.on(':')
+        return fingerprint(bytes, bytes.length);
-                .join(Lists.transform(Bytes.asList(bytes), b -> String.format("%02X", b)));
+    }
+
+    public static String fingerprint(final byte[] bytes, final int segments) {
+        return Joiner.on('\n')
+                .join(
+                        Lists.transform(
+                                Lists.transform(
+                                        Lists.partition(Bytes.asList(bytes), segments),
+                                        s -> Lists.transform(s, b -> String.format("%02X", b))),
+                                hex -> Joiner.on(':').join(hex)));
     }
 
     public void setUserInterfaceCallback(

app/src/main/res/layout/fragment_trust_certificate.xml

@@ -0,0 +1,142 @@
+<?xml version="1.0" encoding="utf-8"?><!--
+  ~ Copyright 2019-2023 Daniel Gultsch
+  ~ Licensed under the Apache License, Version 2.0 (the "License");
+  ~ you may not use this file except in compliance with the License.
+  ~ You may obtain a copy of the License at
+  ~
+  ~     http://www.apache.org/licenses/LICENSE-2.0
+  ~
+  ~ Unless required by applicable law or agreed to in writing, software
+  ~ distributed under the License is distributed on an "AS IS" BASIS,
+  ~ WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+  ~ See the License for the specific language governing permissions and
+  ~ limitations under the License.
+  -->
+
+<layout xmlns:android="http://schemas.android.com/apk/res/android"
+    xmlns:app="http://schemas.android.com/apk/res-auto"
+    xmlns:tools="http://schemas.android.com/tools">
+
+    <androidx.coordinatorlayout.widget.CoordinatorLayout
+        android:layout_width="match_parent"
+        android:layout_height="match_parent">
+
+        <com.google.android.material.appbar.AppBarLayout
+            android:id="@+id/app_bar_layout"
+            android:layout_width="match_parent"
+            android:layout_height="wrap_content"
+            app:liftOnScroll="false"
+            app:elevation="0dp">
+
+            <com.google.android.material.appbar.MaterialToolbar
+                android:id="@+id/material_toolbar"
+                android:layout_width="match_parent"
+                android:layout_height="?attr/actionBarSize"
+                app:title="@string/app_name"
+                app:menu="@menu/activity_setup"
+                app:titleTextColor="?colorPrimary"
+                app:titleCentered="true" />
+
+            <com.google.android.material.progressindicator.LinearProgressIndicator
+                android:layout_width="match_parent"
+                android:layout_height="wrap_content"
+                android:indeterminate="true"
+                android:visibility="@{setupViewModel.isLoading() ? View.VISIBLE : View.INVISIBLE}" />
+
+        </com.google.android.material.appbar.AppBarLayout>
+
+        <androidx.core.widget.NestedScrollView
+            android:layout_width="match_parent"
+            android:layout_height="match_parent"
+            android:fillViewport="true"
+            app:layout_behavior="@string/appbar_scrolling_view_behavior">
+
+
+            <RelativeLayout
+                android:layout_width="match_parent"
+                android:layout_height="match_parent"
+                android:clipToPadding="false"
+                android:minHeight="@dimen/setup_main_min_height"
+                android:orientation="vertical"
+                android:padding="@dimen/setup_screen_padding">
+
+                <TextView
+                    android:id="@+id/header"
+                    android:textColor="?colorError"
+                    android:textAppearance="?textAppearanceTitleMedium"
+                    android:layout_width="wrap_content"
+                    android:layout_height="wrap_content"
+                    android:layout_centerHorizontal="true"
+                    android:layout_marginTop="@dimen/setup_screen_top_margin"
+                    android:text="@string/potential_security_risk_ahead" />
+
+                <TextView
+                    android:id="@+id/warning"
+                    android:textAppearance="?textAppearanceBodyMedium"
+                    android:textColor="?colorError"
+                    android:layout_below="@+id/header"
+                    android:layout_width="wrap_content"
+                    android:layout_marginTop="12sp"
+                    android:layout_centerHorizontal="true"
+                    android:text="@string/trust_certificate_warning"
+                    android:layout_height="wrap_content"/>
+
+                <TextView
+                    android:textAppearance="?textAppearanceBodyMedium"
+                    android:layout_below="@+id/warning"
+                    android:id="@+id/instructions"
+                    android:layout_width="wrap_content"
+                    android:layout_height="wrap_content"
+                    android:layout_marginTop="12sp"
+                    android:layout_centerHorizontal="true"
+                    android:text="@string/trust_certificate_instructions" />
+
+
+                <LinearLayout
+                    android:layout_marginVertical="24dp"
+                    android:id="@+id/password_input_layout"
+                    android:layout_width="488dp"
+                    android:layout_height="wrap_content"
+                    android:layout_centerHorizontal="true"
+                    android:layout_below="@+id/instructions"
+                    android:gravity="center_horizontal"
+                    android:layout_gravity="center_horizontal">
+
+                    <TextView
+                        android:layout_width="wrap_content"
+                        android:layout_height="wrap_content"
+                        android:textAppearance="?textAppearanceBodyLarge"
+                        android:textColor="?colorTertiary"
+                        android:typeface="monospace"
+                        android:text="@{setupViewModel.fingerprint}"
+                        tools:text="2B:F0:58:07:E1:A9:7F:4E\nD5:90:90:98:D5:61:39:12\n90:21:8D:83:C8:52:CB:82\n24:28:B5:43:2F:AE:81:44" />
+
+                </LinearLayout>
+
+                <com.google.android.material.button.MaterialButton
+                    android:id="@+id/next"
+                    android:layout_width="wrap_content"
+                    android:layout_height="wrap_content"
+                    android:layout_alignParentEnd="true"
+                    android:layout_alignParentBottom="true"
+                    android:enabled="@{!setupViewModel.isLoading()}"
+                    android:onClick="@{(v) -> setupViewModel.trustCertificate()}"
+                    android:text="@string/trust_cerficate" />
+
+            </RelativeLayout>
+
+        </androidx.core.widget.NestedScrollView>
+
+
+    </androidx.coordinatorlayout.widget.CoordinatorLayout>
+
+
+    <data>
+
+        <import type="android.view.View" />
+
+        <variable
+            name="setupViewModel"
+            type="im.conversations.android.ui.model.SetupViewModel" />
+    </data>
+</layout>

app/src/main/res/navigation/setup_navigation.xml

@@ -28,6 +28,15 @@
         app:popExitAnim="@anim/slide_to_right"
         app:popUpTo="@+id/hostname" />
 
+    <action
+        android:id="@+id/trustCertificate"
+        app:destination="@+id/certificate"
+        app:enterAnim="@anim/slide_from_right"
+        app:exitAnim="@anim/slide_to_left"
+        app:popEnterAnim="@anim/slide_from_left"
+        app:popExitAnim="@anim/slide_to_right"
+        app:popUpTo="@+id/hostname" />
+
     <action
         android:id="@+id/enterHostname"
         app:destination="@+id/hostname"
@@ -48,6 +57,10 @@
         android:name="im.conversations.android.ui.fragment.setup.HostnameFragment"
         tools:layout="@layout/fragment_hostname" />
 
+    <fragment
+        android:id="@+id/certificate"
+        android:name="im.conversations.android.ui.fragment.setup.TrustCertificateFragment" />
+
     <fragment
         android:id="@+id/password"
         android:name="im.conversations.android.ui.fragment.setup.PasswordFragment"

app/src/main/res/values/strings.xml

@@ -1042,5 +1042,9 @@
     <string name="info_required">Info required</string>
     <string name="invalid">Invalid!</string>
     <string name="certificate_login">Certificate login</string>
+    <string name="potential_security_risk_ahead">Potential security risk ahead</string>
+    <string name="trust_certificate_instructions">To continue compare this SHA-256 fingerprint with that of the server certificate</string>
+    <string name="trust_certificate_warning">The server certificate is not trustworthy. If you don’t know what this means it’s best to go back!</string>
+    <string name="trust_cerficate">Trust certificate</string>
 
 </resources>