FilePermissionStore.java

/*******************************************************************************
 * Copyright (c) 2007, 2014 compeople AG and others.
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License v1.0
 * which accompanies this distribution, and is available at
 * http://www.eclipse.org/legal/epl-v10.html
 *
 * Contributors:
 *    compeople AG - initial API and implementation
 *******************************************************************************/
package org.eclipse.riena.security.simpleservices.authorizationservice.store;

import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.lang.reflect.Constructor;
import java.security.Permission;
import java.security.Permissions;
import java.security.Principal;

import javax.xml.parsers.DocumentBuilder;
import javax.xml.parsers.DocumentBuilderFactory;
import javax.xml.parsers.ParserConfigurationException;

import org.w3c.dom.Document;
import org.w3c.dom.Element;
import org.w3c.dom.NodeList;
import org.xml.sax.InputSource;
import org.xml.sax.SAXException;

import org.eclipse.riena.security.authorizationservice.IPermissionStore;
import org.eclipse.riena.security.common.SecurityFailure;
import org.eclipse.riena.security.common.authorization.PermissionClassFactory;

/**
 * 
 */
public class FilePermissionStore implements IPermissionStore {

	private final Document permissionTree;

	public FilePermissionStore(final File permissionFile) throws SAXException, IOException,
			ParserConfigurationException {
		this(new FileInputStream(permissionFile));
	}

	public FilePermissionStore(final InputStream inputStream) throws ParserConfigurationException, SAXException,
			IOException {
		super();
		final DocumentBuilderFactory dbf = DocumentBuilderFactory.newInstance();
		final DocumentBuilder db = dbf.newDocumentBuilder();
		permissionTree = db.parse(new InputSource(inputStream));
	}

	public Permissions loadPermissions(final Principal principal) {
		final Permissions allPerms = new Permissions();
		final NodeList nl = permissionTree.getDocumentElement().getElementsByTagName("principal"); //$NON-NLS-1$
		for (int i = 0; i < nl.getLength(); i++) {
			final Element el = (Element) nl.item(i);
			final String principalClazz = el.getAttribute("class"); //$NON-NLS-1$
			final String principalName = el.getAttribute("name"); //$NON-NLS-1$
			if (!principalClazz.equals(principal.getClass().getName()) || !principalName.equals(principal.getName())) {
				continue;
			}
			if (principal.getClass().getName().equals(el.getAttribute("class"))) { //$NON-NLS-1$
				final NodeList nlPerms = el.getElementsByTagName("permission"); //$NON-NLS-1$
				for (int x = 0; x < nlPerms.getLength(); x++) {
					final Element ePerm = (Element) nlPerms.item(x);
					final String clazz = ePerm.getAttribute("class"); //$NON-NLS-1$
					final String name = ePerm.getAttribute("name"); //$NON-NLS-1$
					final String action = ePerm.getAttribute("action"); //$NON-NLS-1$
					try {
						// its not good to use Class.forName so we use a specific factory
						final Class<?> permClass = PermissionClassFactory.retrieveClass(clazz);
						Constructor<?> constr;
						Permission perm;
						if (action != null && action.length() > 0) {
							try {
								final int actInt = Integer.parseInt(action);
								constr = permClass.getConstructor(String.class, int.class);
								perm = (Permission) constr.newInstance(name, actInt);
							} catch (final NumberFormatException e) {
								constr = permClass.getConstructor(String.class, String.class);
								perm = (Permission) constr.newInstance(name, action);
							}
						} else {
							constr = permClass.getConstructor(String.class);
							perm = (Permission) constr.newInstance(name);
						}
						if (perm != null) {
							allPerms.add(perm);
						}
					} catch (final Exception e) {
						throw new SecurityFailure("Creating permission '" + clazz + "' failed", e); //$NON-NLS-1$ //$NON-NLS-2$
					}
				}
			}
		}
		return allPerms;
	}
}