Generate SSH keys on the device

app/build.gradle

@@ -191,8 +191,15 @@ dependencies {
 
     implementation "io.github.rburgst:okhttp-digest:$versions.okhttp_digest"
 
+    // Git sync over SSH
     implementation "org.eclipse.jgit:org.eclipse.jgit:$versions.jgit"
-    implementation "org.eclipse.jgit:org.eclipse.jgit.ssh.jsch:$versions.jgit"
+    implementation("org.eclipse.jgit:org.eclipse.jgit.ssh.apache:$versions.jgit") {
+        // Resolves DuplicatePlatformClasses lint error
+        exclude group: 'org.apache.sshd', module: 'sshd-osgi'
+    }
+    implementation 'androidx.security:security-crypto:1.1.0-alpha03'
+    implementation 'androidx.biometric:biometric-ktx:1.2.0-alpha04'
+
 }
 
 repositories {

app/src/main/AndroidManifest.xml

@@ -122,6 +122,11 @@
             android:windowSoftInputMode="stateAlwaysHidden|adjustResize">
         </activity>
 
+        <activity
+            android:name=".android.ui.SshKeygenActivity"
+            android:windowSoftInputMode="stateAlwaysHidden">
+        </activity>
+
         <activity
             android:name=".android.ui.repo.webdav.WebdavRepoActivity"
             android:windowSoftInputMode="stateAlwaysHidden|adjustResize">

app/src/main/java/com/orgzly/android/App.java

@@ -76,4 +76,7 @@ public static Context getAppContext() {
     public static void setCurrentActivity(CommonActivity currentCommonActivity) {
         currentActivity = currentCommonActivity;
     }
+
+    public static CommonActivity getCurrentActivity() { return currentActivity; }
+
 }

app/src/main/java/com/orgzly/android/AppIntent.java

@@ -38,6 +38,10 @@ public class AppIntent {
 
     public static final String ACTION_SHOW_SNACKBAR = "com.orgzly.intent.action.SHOW_SNACKBAR";
 
+    public static final String ACTION_REJECT_REMOTE_HOST_KEY = "com.orgzly.intent.action.REJECT_REMOTE_HOST_KEY";
+    public static final String ACTION_ACCEPT_REMOTE_HOST_KEY = "com.orgzly.intent.action.ACCEPT_REMOTE_HOST_KEY";
+    public static final String ACTION_ACCEPT_AND_STORE_REMOTE_HOST_KEY = "com.orgzly.intent.action.ACCEPT_AND_STORE_REMOTE_HOST_KEY";
+
     public static final String EXTRA_MESSAGE = "com.orgzly.intent.extra.MESSAGE";
     public static final String EXTRA_BOOK_ID = "com.orgzly.intent.extra.BOOK_ID";
     public static final String EXTRA_BOOK_PREFACE = "com.orgzly.intent.extra.BOOK_PREFACE";

app/src/main/java/com/orgzly/android/NotificationChannels.kt

@@ -20,6 +20,7 @@ object NotificationChannels {
     const val REMINDERS = "reminders"
     const val SYNC_PROGRESS = "sync-progress"
     const val SYNC_FAILED = "sync-failed"
+    const val SYNC_PROMPT = "sync-prompt"
 
     @JvmStatic
     fun createAll(context: Context) {
@@ -28,6 +29,7 @@ object NotificationChannels {
             createForReminders(context)
             createForSyncProgress(context)
             createForSyncFailed(context)
+            createForSyncPrompt(context)
         }
     }
 
@@ -111,4 +113,25 @@ object NotificationChannels {
 
         context.getNotificationManager().createNotificationChannel(channel)
     }
+
+    @RequiresApi(Build.VERSION_CODES.O)
+    private fun createForSyncPrompt(context: Context) {
+        if (Build.VERSION.SDK_INT < Build.VERSION_CODES.O) {
+            return
+        }
+
+        val id = SYNC_PROMPT
+        val name = "Sync prompt"
+        val description = "Display sync prompt"
+        val importance = NotificationManager.IMPORTANCE_HIGH
+
+        val channel = NotificationChannel(id, name, importance)
+
+        channel.description = description
+
+        channel.setShowBadge(false)
+
+        val mNotificationManager = context.getSystemService(Context.NOTIFICATION_SERVICE) as NotificationManager
+        mNotificationManager.createNotificationChannel(channel)
+    }
 }

app/src/main/java/com/orgzly/android/git/GitFileSynchronizer.java

@@ -1,11 +1,15 @@
 package com.orgzly.android.git;
 
+import static com.orgzly.android.ui.AppSnackbarUtils.showSnackbar;
+
+import android.app.Activity;
 import android.content.Context;
 import android.net.Uri;
 import android.util.Log;
 
 import androidx.annotation.NonNull;
 
+import com.orgzly.R;
 import com.orgzly.android.App;
 import com.orgzly.android.util.MiscUtils;
 
@@ -14,14 +18,14 @@
 import org.eclipse.jgit.api.MergeResult;
 import org.eclipse.jgit.api.ResetCommand;
 import org.eclipse.jgit.api.Status;
-import org.eclipse.jgit.api.TransportCommand;
 import org.eclipse.jgit.api.errors.GitAPIException;
 import org.eclipse.jgit.lib.Constants;
 import org.eclipse.jgit.lib.ObjectId;
 import org.eclipse.jgit.lib.Ref;
 import org.eclipse.jgit.lib.Repository;
 import org.eclipse.jgit.revwalk.RevCommit;
 import org.eclipse.jgit.revwalk.RevWalk;
+import org.eclipse.jgit.transport.PushResult;
 import org.eclipse.jgit.treewalk.TreeWalk;
 
 import java.io.File;
@@ -33,14 +37,18 @@
 import java.util.TimeZone;
 
 public class GitFileSynchronizer {
-    private static String TAG = GitFileSynchronizer.class.getSimpleName();
+    private final static String TAG = GitFileSynchronizer.class.getSimpleName();
+
+    private final Git git;
+    private final GitPreferences preferences;
+    private final Context context;
+    private final Activity currentActivity = App.getCurrentActivity();
 
-    private Git git;
-    private GitPreferences preferences;
 
     public GitFileSynchronizer(Git g, GitPreferences prefs) {
         git = g;
         preferences = prefs;
+        context = App.getAppContext();
     }
 
     private GitTransportSetter transportSetter() {
@@ -67,12 +75,17 @@ public void retrieveLatestVersionOfFile(
         MiscUtils.copyFile(repoDirectoryFile(repositoryPath), destination);
     }
 
-    private void fetch() throws GitAPIException {
-        transportSetter()
-                .setTransport(git.fetch()
-                        .setRemote(preferences.remoteName())
-                        .setRemoveDeletedRefs(true))
-                .call();
+    private void fetch() throws IOException {
+        try {
+            transportSetter()
+                    .setTransport(git.fetch()
+                            .setRemote(preferences.remoteName())
+                            .setRemoveDeletedRefs(true))
+                    .call();
+        } catch (GitAPIException e) {
+            e.printStackTrace();
+            throw new IOException(e.getMessage());
+        }
     }
 
     public void checkoutSelected() throws GitAPIException {
@@ -93,22 +106,6 @@ public boolean mergeWithRemote() throws IOException {
         return false;
     }
 
-    public boolean mergeAndPushToRemote() throws IOException {
-        boolean success = mergeWithRemote();
-        if (success) try {
-            transportSetter().setTransport(git.push().setRemote(preferences.remoteName())).call();
-        } catch (GitAPIException e) {}
-        return success;
-    }
-
-    public void updateAndCommitFileFromRevision(
-            File sourceFile, String repositoryPath,
-            ObjectId fileRevision, RevCommit revision) throws IOException {
-        ensureRepoIsClean();
-        if (updateAndCommitFileFromRevision(sourceFile, repositoryPath, fileRevision))
-            return;
-    }
-
     private String getShortHash(ObjectId hash) {
         String shortHash = hash.getName();
         try {
@@ -140,8 +137,8 @@ public boolean updateAndCommitFileFromRevisionAndMerge(
         try {
             git.branchDelete().setBranchNames(mergeBranch).call();
         } catch (GitAPIException e) {}
-        Boolean mergeSucceeded = true;
-        Boolean doCleanup = false;
+        boolean mergeSucceeded = true;
+        boolean doCleanup = false;
         try {
             RevCommit mergeTarget = currentHead();
             // Try to use the branch "orgzly-pre-sync-marker" to find a good point for branching off.
@@ -239,16 +236,38 @@ public void tryPushIfHeadDiffersFromRemote() {
     }
 
     public void tryPush() {
-        final TransportCommand pushCommand = transportSetter().setTransport(
+        final var pushCommand = transportSetter().setTransport(
                 git.push().setRemote(preferences.remoteName()));
+        final Object monitor = new Object();
 
         App.EXECUTORS.diskIO().execute(() -> {
             try {
-                pushCommand.call();
+                Iterable<PushResult> results = (Iterable<PushResult>) pushCommand.call();
+                // org.eclipse.jgit.api.PushCommand swallows some errors without throwing exceptions.
+                if (!results.iterator().next().getMessages().isEmpty()) {
+                    if (currentActivity != null) {
+                        showSnackbar(currentActivity, results.iterator().next().getMessages());
+                    }
+                }
+                synchronized (monitor) {
+                    monitor.notify();
+                }
             } catch (GitAPIException e) {
-                e.printStackTrace();
+                if (currentActivity != null) {
+                    showSnackbar(
+                            currentActivity,
+                            String.format("Failed to push to remote: %s", e.getMessage())
+                    );
+                }
             }
         });
+        synchronized (monitor) {
+            try {
+                monitor.wait();
+            } catch (InterruptedException e) {
+                e.printStackTrace();
+            }
+        }
     }
 
     private void gitResetMerge() throws IOException, GitAPIException {
@@ -274,7 +293,11 @@ public void setBranchAndGetLatest() throws IOException {
             // Point a "marker" branch to the current head, so that we know a good starting commit
             // for merge conflict branches.
             git.branchCreate().setName("orgzly-pre-sync-marker").setForce(true).call();
-            fetch();
+        } catch (GitAPIException e) {
+            throw new IOException(context.getString(R.string.git_sync_error_failed_set_marker_branch));
+        }
+        fetch();
+        try {
             RevCommit current = currentHead();
             RevCommit mergeTarget = getCommit(
                     String.format("%s/%s", preferences.remoteName(), git.getRepository().getBranch()));
@@ -290,8 +313,7 @@ public void setBranchAndGetLatest() throws IOException {
                 }
             }
         } catch (GitAPIException e) {
-            e.printStackTrace();
-            throw new IOException("Failed to update from remote");
+            throw new IOException(e.getMessage());
         }
     }
 
@@ -348,7 +370,7 @@ public void addAndCommitNewFile(File sourceFile, String repositoryPath) throws I
         updateAndCommitFile(sourceFile, repositoryPath);
     }
 
-    private RevCommit updateAndCommitFile(
+    private void updateAndCommitFile(
             File sourceFile, String repositoryPath) throws IOException {
         File destinationFile = repoDirectoryFile(repositoryPath);
         MiscUtils.copyFile(sourceFile, destinationFile);
@@ -359,7 +381,6 @@ private RevCommit updateAndCommitFile(
         } catch (GitAPIException e) {
             throw new IOException("Failed to commit changes.");
         }
-        return currentHead();
     }
 
     private void commit(String message) throws GitAPIException {
@@ -414,9 +435,8 @@ public boolean isEmptyRepo() throws IOException{
     }
 
     public ObjectId getFileRevision(String pathString, RevCommit commit) throws IOException {
-        ObjectId objectId = TreeWalk.forPath(
+        return TreeWalk.forPath(
                 git.getRepository(), pathString, commit.getTree()).getObjectId(0);
-        return objectId;
     }
 
     public boolean fileMatchesInRevisions(String pathString, RevCommit start, RevCommit end)

app/src/main/java/com/orgzly/android/git/GitPreferencesFromRepoPrefs.java

@@ -22,9 +22,7 @@ public GitTransportSetter createTransportSetter() {
             return new HTTPSTransportSetter(username, password);
         } else {
             // assume SSH, since ssh:// usually isn't specified as the scheme when cloning via SSH.
-            String sshKeyPath = repoPreferences.getStringValueWithGlobalDefault(
-                    R.string.pref_key_git_ssh_key_path, "orgzly");
-            return new GitSSHKeyTransportSetter(sshKeyPath);
+            return new GitSshKeyTransportSetter();
         }
     }