Improve UI for account recovery

briar-android/src/main/java/org/briarproject/briar/android/socialbackup/recover/OwnerReturnShardActivity.java

@@ -5,6 +5,7 @@ import android.os.Bundle;
 import android.view.MenuItem;
 import android.widget.Toast;
 
+import org.briarproject.bramble.api.FormatException;
 import org.briarproject.bramble.api.nullsafety.MethodsNotNullByDefault;
 import org.briarproject.bramble.api.nullsafety.ParametersNotNullByDefault;
 import org.briarproject.briar.R;
@@ -14,6 +15,7 @@ import org.briarproject.briar.android.fragment.BaseFragment;
 import org.briarproject.briar.api.socialbackup.ReturnShardPayload;
 import org.briarproject.briar.api.socialbackup.recovery.SecretOwnerTask;
 
+import java.security.GeneralSecurityException;
 import java.util.logging.Logger;
 
 import javax.annotation.Nullable;
@@ -128,8 +130,25 @@ public class OwnerReturnShardActivity extends BaseActivity
 					"Success - got shard" + (added ? "" : " duplicate"),
 					Toast.LENGTH_SHORT).show();
 			if (added && viewModel.canRecover()) {
+				LOG.info("Secret key recovered");
+				int version = 0;
+				try {
+					version = viewModel.recover();
+				} catch (GeneralSecurityException e) {
+					LOG.warning("Unable to decrypt backup" + e.toString());
+					Toast.makeText(this,
+							"Unable to decrypt backup",
+							Toast.LENGTH_LONG).show();
+					return;
+				} catch (FormatException e) {
+					LOG.warning("Unable to parse backup" + e.getMessage() + e.getStackTrace().toString());
+					Toast.makeText(this,
+							"Unable to parse backup",
+							Toast.LENGTH_LONG).show();
+					return;
+				}
 				Toast.makeText(this,
-						"Secret key recovered!",
+						"Account recovered! " + version,
 						Toast.LENGTH_LONG).show();
 				finish();
 				return;

briar-android/src/main/java/org/briarproject/briar/android/socialbackup/recover/OwnerReturnShardViewModel.java

@@ -6,6 +6,7 @@ import android.net.wifi.WifiInfo;
 import android.net.wifi.WifiManager;
 import android.util.DisplayMetrics;
 
+import org.briarproject.bramble.api.FormatException;
 import org.briarproject.bramble.api.crypto.SecretKey;
 import org.briarproject.bramble.api.lifecycle.IoExecutor;
 import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
@@ -13,10 +14,13 @@ import org.briarproject.bramble.api.system.AndroidExecutor;
 import org.briarproject.briar.android.contact.add.nearby.QrCodeUtils;
 import org.briarproject.briar.android.viewmodel.LiveEvent;
 import org.briarproject.briar.android.viewmodel.MutableLiveEvent;
+import org.briarproject.briar.api.socialbackup.BackupPayload;
 import org.briarproject.briar.api.socialbackup.DarkCrystal;
 import org.briarproject.briar.api.socialbackup.ReturnShardPayload;
 import org.briarproject.briar.api.socialbackup.Shard;
 import org.briarproject.briar.api.socialbackup.recovery.SecretOwnerTask;
+import org.briarproject.briar.socialbackup.BackupPayloadDecoder;
+import org.briarproject.briar.socialbackup.SocialBackup;
 
 import java.net.InetAddress;
 import java.net.UnknownHostException;
@@ -53,6 +57,7 @@ class OwnerReturnShardViewModel extends AndroidViewModel
 	private final Executor ioExecutor;
 	private final SecretOwnerTask task;
 	private final DarkCrystal darkCrystal;
+	private final BackupPayloadDecoder backupPayloadDecoder;
 
 	private final MutableLiveEvent<Boolean> showQrCodeFragment =
 			new MutableLiveEvent<>();
@@ -65,16 +70,19 @@ class OwnerReturnShardViewModel extends AndroidViewModel
 	private ArrayList<ReturnShardPayload> recoveredShards = new ArrayList<>();
 	private Bitmap qrCodeBitmap;
 	private WifiManager wifiManager;
+	private SecretKey secretKey;
 
 	@Inject
 	OwnerReturnShardViewModel(Application app,
 			AndroidExecutor androidExecutor,
 			SecretOwnerTask task,
 			DarkCrystal darkCrystal,
+			BackupPayloadDecoder backupPayloadDecoder,
 			@IoExecutor Executor ioExecutor) {
 		super(app);
 		this.androidExecutor = androidExecutor;
 		this.ioExecutor = ioExecutor;
+		this.backupPayloadDecoder = backupPayloadDecoder;
 		this.darkCrystal = darkCrystal;
 		this.task = task;
 		wifiManager = (WifiManager) app.getSystemService(WIFI_SERVICE);
@@ -236,15 +244,21 @@ class OwnerReturnShardViewModel extends AndroidViewModel
 			// TODO check shards all have same secret id
 		   shards.add(returnShardPayload.getShard());
 		}
-		SecretKey secretKey;
 		try {
 			secretKey = darkCrystal.combineShards(shards);
 		} catch (GeneralSecurityException e) {
 			// TODO handle error message
 			return false;
 		}
-		// TODO find backup with highest version number
-//		recoveredShards.get(0).getBackupPayload();
 		return true;
 	}
+
+	public int recover() throws FormatException, GeneralSecurityException {
+		if (secretKey == null) throw new GeneralSecurityException();
+		// TODO find backup with highest version number
+		BackupPayload backupPayload = recoveredShards.get(0).getBackupPayload();
+		SocialBackup decodedBackup = backupPayloadDecoder.decodeBackupPayload(secretKey, backupPayload);
+		int version = decodedBackup.getVersion();
+		return version;
+	}
 }