Add error messages

administrator/language/en-GB/lib_joomla.ini

@@ -655,11 +655,15 @@ JLIB_INSTALLER_SQL_BEGIN="Start of SQL updates."
 JLIB_INSTALLER_SQL_BEGIN_SCHEMA="The current database version (schema) is %s."
 JLIB_INSTALLER_SQL_END="End of SQL updates."
 JLIB_INSTALLER_SQL_END_NOT_COMPLETE="End of SQL updates - INCOMPLETE."
+JLIB_INSTALLER_TUF_FREEZE_ATTACK="Update not possible because the offered update is expired."
+JLIB_INSTALLER_TUF_INVALID_METADATA="The saved TUF update information is invalid."
+JLIB_INSTALLER_TUF_NOT_AVAILABLE="TUF is not available for extensions yet."
+JLIB_INSTALLER_TUF_ROLLBACK_ATTACK="Update not possible because the offered update version is older than the current installed version."
+JLIB_INSTALLER_TUF_SIGNATURE_THRESHOLD="Update not possible because the offered update has not enough signatures."
 JLIB_INSTALLER_UNINSTALL="Uninstall"
 JLIB_INSTALLER_UPDATE="Update"
 JLIB_INSTALLER_UPDATE_LOG_QUERY="Ran query from file %1$s. Query text: %2$s."
 JLIB_INSTALLER_WARNING_UNABLE_TO_INSTALL_CONTENT_LANGUAGE="Unable to create a content language for %s language: %s"
-JLIB_INSTALLER_TUF_NOT_AVAILABLE="TUF is not available for extensions yet."
 
 JLIB_JS_AJAX_ERROR_CONNECTION_ABORT="A connection abort has occurred while fetching the JSON data."
 JLIB_JS_AJAX_ERROR_NO_CONTENT="No content was returned."

libraries/src/TUF/TufValidation.php

@@ -9,13 +9,14 @@
 namespace Joomla\CMS\TUF;
 
 use Joomla\CMS\Factory;
+use Joomla\CMS\Language\Text;
+use Joomla\CMS\TUF\HttpFileFetcher;
 use Joomla\Database\DatabaseDriver;
 use Joomla\Database\ParameterType;
 use Symfony\Component\OptionsResolver\Exception\InvalidOptionsException;
 use Symfony\Component\OptionsResolver\Exception\UndefinedOptionsException;
 use Symfony\Component\OptionsResolver\OptionsResolver;
 use Tuf\Client\GuzzleFileFetcher;
-use Joomla\CMS\TUF\HttpFileFetcher;
 use Tuf\Client\Updater;
 use Tuf\Exception\Attack\FreezeAttackException;
 use Tuf\Exception\Attack\RollbackAttackException;
@@ -129,16 +130,42 @@ public function getValidUpdate()
 
 			return $storage['targets.json'];
 		}
-		catch (FreezeAttackException | MetadataException | SignatureThresholdException | RollbackAttackException $e)
+		catch (MetadataException $e)
 		{
-			// When the validation fails, for example when one file is written but the others don't, we roll back everything
-			// and cancel the update
-			$query = $db->getQuery(true)
-				->delete($db->quoteName('#__tuf_metadata'))
-				->columns(['snapshot_json', 'targets_json', 'timestamp_json']);
-			$db->setQuery($query);
-
+			$this->rollBackTufMetadata();
+			Factory::getApplication()->enqueueMessage(Text::_('JLIB_INSTALLER_TUF_INVALID_METADATA'), 'error');
+			return null;
+		}
+		catch (FreezeAttackException $e)
+		{
+			$this->rollBackTufMetadata();
+			Factory::getApplication()->enqueueMessage(Text::_('JLIB_INSTALLER_TUF_FREEZE_ATTACK'), 'error');
 			return null;
 		}
+		catch (RollbackAttackException $e)
+		{
+			$this->rollBackTufMetadata();
+			Factory::getApplication()->enqueueMessage(Text::_('JLIB_INSTALLER_TUF_ROLLBACK_ATTACK'), 'error');
+			return null;
+		}
+		catch (SignatureThresholdException $e)
+		{
+			$this->rollBackTufMetadata();
+			Factory::getApplication()->enqueueMessage(Text::_('JLIB_INSTALLER_TUF_SIGNATURE_THRESHOLD'), 'error');
+			return null;
+		}
+	}
+
+	/**
+	 * When the validation fails, for example when one file is written but the others don't, we roll back everything
+	 *
+	 * @return void
+	 */
+	private function rollBackTufMetadata() {
+		$db = Factory::getContainer()->get(DatabaseDriver::class);
+		$query = $db->getQuery(true)
+			->delete($db->quoteName('#__tuf_metadata'))
+			->columns(['snapshot_json', 'targets_json', 'timestamp_json']);
+		$db->setQuery($query);
 	}
 }

libraries/src/Updater/Adapter/TufAdapter.php

@@ -57,14 +57,17 @@ public function findUpdate($options)
 		$updates = [];
 		$targets = $this->getUpdateTargets($options);
 
-		foreach ($targets as $target)
+		if ($targets)
 		{
-			$updateTable = Table::getInstance('update');
-			$updateTable->set('update_site_id', $options['update_site_id']);
+			foreach ($targets as $target)
+			{
+				$updateTable = Table::getInstance('update');
+				$updateTable->set('update_site_id', $options['update_site_id']);
 
-			$updateTable->bind($target);
+				$updateTable->bind($target);
 
-			$updates[] = $updateTable;
+				$updates[] = $updateTable;
+			}
 		}
 
 		return array('update_sites' => array(), 'updates' => $updates);