--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/src/java/de/uapcore/lightpit/DatabaseFacade.java Sat Dec 30 20:35:23 2017 +0100
@@ -0,0 +1,211 @@
+/*
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS HEADER.
+ *
+ * Copyright 2017 Mike Becker. All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ *
+ * 2. Redistributions in binary form must reproduce the above copyright
+ * notice, this list of conditions and the following disclaimer in the
+ * documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
+ * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ *
+ */
+package de.uapcore.lightpit;
+
+import java.sql.Connection;
+import java.sql.DatabaseMetaData;
+import java.sql.SQLException;
+import java.util.Optional;
+import javax.naming.Context;
+import javax.naming.InitialContext;
+import javax.naming.NamingException;
+import javax.servlet.ServletContext;
+import javax.servlet.ServletContextEvent;
+import javax.servlet.ServletContextListener;
+import javax.servlet.annotation.WebListener;
+import javax.sql.DataSource;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+/**
+ * Provides access to different privilege layers within the database.
+ */
+@WebListener
+public final class DatabaseFacade implements ServletContextListener {
+
+ private static final Logger LOG = LoggerFactory.getLogger(DatabaseFacade.class);
+
+ /**
+ * Timeout in seconds for the validation test.
+ */
+ private static final int DB_TEST_TIMEOUT = 10;
+
+ /**
+ * The default schema to test against when validating the connection.
+ *
+ * May be overridden by context parameter.
+ */
+ private static final String DB_DEFAULT_SCHEMA = "lightpit";
+
+ /**
+ * The attribute name in the servlet context under which an instance of this class can be found.
+ */
+ public static final String SC_ATTR_NAME = DatabaseFacade.class.getName();
+ private ServletContext sc;
+
+ private static final String PRIVILEGED_DS_JNDI_NAME = "jdbc/lightpit/dbo";
+ private Optional<DataSource> privilegedDataSource;
+
+ private static final String UNPRIVILEGED_DS_JNDI_NAME = "jdbc/lightpit/app";
+ private Optional<DataSource> unprivilegedDataSource;
+
+
+ /**
+ * Returns an optional privileged data source.
+ *
+ * Privileged data sources should be able to execute any kind of DDL
+ * statements to perform installation or configuration steps.
+ *
+ * This optional should always be empty in live operation. Modules which
+ * provide installation or configuration steps MUST check the presence of
+ * a privileged data source and SHOULD display an informative message if
+ * it is currently disabled.
+ *
+ * @return an optional privileged data source
+ */
+ public Optional<DataSource> getPrivilegedDataSource() {
+ return privilegedDataSource;
+ }
+
+ /**
+ * Returns an optional unprivileged data source.
+ *
+ * The Optional returned should never be empty. However, if something goes
+ * wrong during initialization, the data source might be absent.
+ * Hence, users of this data source are forced to check the existence.
+ *
+ * @return an optional unprivileged data source
+ */
+ public Optional<DataSource> getUnprivilegedDataSource() {
+ return unprivilegedDataSource;
+ }
+
+ /**
+ * Returns the JNDI resource name of the privileged data source.
+ *
+ * Modules may use this information to provide useful information to the user.
+ *
+ * @return the JNDI resource name of the privileged data source
+ */
+ public String getPrivilegedDataSourceJNDIName() {
+ return PRIVILEGED_DS_JNDI_NAME;
+ }
+
+ /**
+ * Returns the JNDI resource name of the unprivileged data source.
+ *
+ * Modules may use this information to provide useful information to the user.
+ *
+ * @return the JNDI resource name of the unprivileged data source
+ */
+ public String getUnprivilegedDataSourceJNDIName() {
+ return UNPRIVILEGED_DS_JNDI_NAME;
+ }
+
+ private static void checkConnection(DataSource ds, String testSchema, String errMsg) {
+ try (Connection conn = ds.getConnection()) {
+ if (!conn.isValid(DB_TEST_TIMEOUT)) {
+ throw new SQLException("Validation check failed.");
+ }
+ if (conn.isReadOnly()) {
+ throw new SQLException("Connection is read-only and thus unusable.");
+ }
+ if (!conn.getSchema().equals(testSchema)) {
+ throw new SQLException(String.format("Connection is not configured to use the schema %s.", testSchema));
+ }
+ DatabaseMetaData metaData = conn.getMetaData();
+ LOG.info("Connections as {} to {}/{} ready to go.", metaData.getUserName(), metaData.getURL(), conn.getSchema());
+ } catch (SQLException ex) {
+ LOG.error(errMsg, ex);
+ }
+ }
+
+ private static Optional<DataSource> retrievePrivilegedDataSource(Context ctx) {
+ DataSource ret = null;
+ try {
+ ret = (DataSource)ctx.lookup(PRIVILEGED_DS_JNDI_NAME);
+ LOG.info("Privileged data source {} retrieved from context.", PRIVILEGED_DS_JNDI_NAME);
+ LOG.warn("Your application may be vulnerable due to privileged database access. Make sure that privileged data sources are only available during installation or configuration.");
+ } catch (NamingException ex) {
+ LOG.info("Privileged data source not available. This is perfectly OK. Activate only, if you need to do installation or configuration.");
+ /* in case the absence of the DataSource is not intended, log something more useful on debug level */
+ LOG.debug("Reason for the missing data source: ", ex);
+ }
+ return Optional.ofNullable(ret);
+ }
+
+ private static Optional<DataSource> retrieveUnprivilegedDataSource(Context ctx) {
+ DataSource ret = null;
+ try {
+ ret = (DataSource)ctx.lookup(UNPRIVILEGED_DS_JNDI_NAME);
+ LOG.info("Unprivileged data source retrieved.");
+ } catch (NamingException ex) {
+ LOG.error("Unprivileged data source {} not available.", UNPRIVILEGED_DS_JNDI_NAME);
+ /* for the unprivileged DataSource log the exception on error level (ordinary admins could find this useful) */
+ LOG.error("Reason for the missing data source: ", ex);
+ }
+ return Optional.ofNullable(ret);
+ }
+
+ @Override
+ public void contextInitialized(ServletContextEvent sce) {
+ sc = sce.getServletContext();
+
+ privilegedDataSource = unprivilegedDataSource = null;
+
+ final String contextName = Optional
+ .ofNullable(sc.getInitParameter(Constants.CTX_ATTR_JNDI_CONTEXT))
+ .orElse("java:comp/env");
+ final String dbSchema = Optional
+ .ofNullable(sc.getInitParameter(Constants.CTX_ATTR_DB_SCHEMA))
+ .orElse(DB_DEFAULT_SCHEMA);
+
+ try {
+ LOG.debug("Trying to access JNDI context {}...", contextName);
+ Context initialCtx = new InitialContext();
+ Context ctx = (Context) initialCtx.lookup(contextName);
+
+ privilegedDataSource = retrievePrivilegedDataSource(ctx);
+ unprivilegedDataSource = retrieveUnprivilegedDataSource(ctx);
+
+ privilegedDataSource.ifPresent((ds) -> checkConnection(ds, dbSchema, "Checking privileged connection failed"));
+ unprivilegedDataSource.ifPresent((ds) -> checkConnection(ds, dbSchema, "Checking unprivileged connection failed"));
+ } catch (NamingException | ClassCastException ex) {
+ LOG.error("Cannot access JNDI resources.", ex);
+ }
+
+ sc.setAttribute(SC_ATTR_NAME, this);
+ LOG.info("Database facade injected into ServletContext.");
+ }
+
+ @Override
+ public void contextDestroyed(ServletContextEvent sce) {
+ privilegedDataSource = unprivilegedDataSource = null;
+ }
+}