/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements. See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership. The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License. You may obtain a copy of the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing,
 * software distributed under the License is distributed on an
 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
 * KIND, either express or implied. See the License for the
 * specific language governing permissions and limitations
 * under the License.
 */
package org.apache.webbeans.util;

import java.io.IOException;
import java.io.InputStream;
import java.io.ObjectInputStream;
import java.io.ObjectStreamClass;
import java.lang.reflect.Proxy;

public class OwbCustomObjectInputStream extends ObjectInputStream
{
    public static final BlacklistClassResolver BLACKLIST_CLASSES = new BlacklistClassResolver(
        toArray(System.getProperty(
            "openwebbeans.serialization.class.blacklist",
            "org.codehaus.groovy.runtime.,org.apache.commons.collections.functors.,org.apache.xalan")),
        toArray(System.getProperty("openwebbeans.serialization.class.whitelist")));

    private ClassLoader classLoader;

    public OwbCustomObjectInputStream(InputStream in, ClassLoader classLoader) throws IOException
    {
        super(in);
        this.classLoader = classLoader;
    }
    
    @Override
    protected Class<?> resolveClass(ObjectStreamClass desc) throws ClassNotFoundException
    {
        return Class.forName(BLACKLIST_CLASSES.check(desc.getName()), false, classLoader);
    }

    @Override
    protected Class resolveProxyClass(String[] interfaces) throws IOException, ClassNotFoundException
    {
        final Class[] cinterfaces = new Class[interfaces.length];
        for (int i = 0; i < interfaces.length; i++)
        {
            cinterfaces[i] = Class.forName(interfaces[i], false, classLoader);
        }

        try
        {
            return Proxy.getProxyClass(classLoader, cinterfaces);
        }
        catch (IllegalArgumentException e)
        {
            throw new ClassNotFoundException(null, e);
        }
    }

    private static String[] toArray(final String property)
    {
        return property == null ? null : property.split(" *, *");
    }

    private static class BlacklistClassResolver
    {
        private final String[] blacklist;
        private final String[] whitelist;

        protected BlacklistClassResolver(final String[] blacklist, final String[] whitelist)
        {
            this.whitelist = whitelist;
            this.blacklist = blacklist;
        }

        protected boolean isBlacklisted(final String name)
        {
            return (whitelist != null && !contains(whitelist, name)) || contains(blacklist, name);
        }

        public final String check(final String name)
        {
            if (isBlacklisted(name))
            {
                throw new SecurityException(name + " is not whitelisted as deserialisable, prevented before loading.");
            }
            return name;
        }

        private static boolean contains(final String[] list, String name)
        {
            if (list != null)
            {
                for (final String white : list)
                {
                    if (name.startsWith(white))
                    {
                        return true;
                    }
                }
            }
            return false;
        }
    }
}
