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Xerces2 is the next generation of high performance, fully compliant XML parsers in the Apache Xerces family. This new version of Xerces introduces the Xerces Native Interface (XNI), a complete framework for building parser components and configurations that is extremely modular and easy to program. The Apache Xerces2 parser is the reference implementation of XNI but other parser components, configurations, and parsers can be written using the Xerces Native Interface. For complete design and implementation documents, refer to the XNI Manual. Xerces2 is a fully conforming XML Schema 1.0 processor. A partial experimental implementation of the XML Schema 1.1 Structures and Datatypes Working Drafts (December 2009) and an experimental implementation of the XML Schema Definition Language (XSD): Component Designators (SCD) Candidate Recommendation (January 2010) are provided for evaluation. For more information, refer to the XML Schema page. Xerces2 also provides a complete implementation of the Document Object Model Level 3 Core and Load/Save W3C Recommendations and provides a complete implementation of the XML Inclusions (XInclude) W3C Recommendation. It also provides support for OASIS XML Catalogs v1.1. Xerces2 is able to parse documents written according to the XML 1.1 Recommendation, except that it does not yet provide an option to enable normalization checking as described in section 2.13 of this specification. It also handles namespaces according to the XML Namespaces 1.1 Recommendation, and will correctly serialize XML 1.1 documents if the DOM level 3 load/save APIs are in use.

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/*
 * 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.xerces.util;

/**
 * This class is a container for parser settings that relate to 
 * security, or more specifically, it is intended to be used to prevent denial-of-service 
 * attacks from being launched against a system running Xerces.  
 * Any component that is aware of a denial-of-service attack that can arise
 * from its processing of a certain kind of document may query its Component Manager
 * for the property (http://apache.org/xml/properties/security-manager) 
 * whose value will be an instance of this class.  
 * If no value has been set for the property, the component should proceed in the "usual" (spec-compliant)
 * manner.  If a value has been set, then it must be the case that the component in
 * question needs to know what method of this class to query.  This class
 * will provide defaults for all known security issues, but will also provide
 * setters so that those values can be tailored by applications that care.
 *
 * @author  Neil Graham, IBM
 *
 * @version $Id: SecurityManager.java 447241 2006-09-18 05:12:57Z mrglavas $
 */
public final class SecurityManager {

    //
    // Constants
    //

    /** Default value for entity expansion limit. **/
    private final static int DEFAULT_ENTITY_EXPANSION_LIMIT = 100000;
    
    /** Default value of number of nodes created. **/
    private final static int DEFAULT_MAX_OCCUR_NODE_LIMIT = 3000;

    //
    // Data
    //

    /** Entity expansion limit. **/
    private int entityExpansionLimit;
    
    /** W3C XML Schema maxOccurs limit. **/
    private int maxOccurLimit;

    /**
     * Default constructor.  Establishes default values 
     * for known security vulnerabilities.
     */  
    public SecurityManager() {
        entityExpansionLimit = DEFAULT_ENTITY_EXPANSION_LIMIT;
        maxOccurLimit = DEFAULT_MAX_OCCUR_NODE_LIMIT ;
    }

    /**
     * Sets the number of entity expansions that the
     * parser should permit in a document.
     *
     * @param limit the number of entity expansions
     * permitted in a document
     */
    public void setEntityExpansionLimit(int limit) {
        entityExpansionLimit = limit;
    }

    /**
     * Returns the number of entity expansions 
     * that the parser permits in a document.
     *
     * @return the number of entity expansions
     * permitted in a document
     */
    public int getEntityExpansionLimit() {
        return entityExpansionLimit;
    }
    
    /**
     * Sets the limit of the number of content model nodes 
     * that may be created when building a grammar for a W3C 
     * XML Schema that contains maxOccurs attributes with values
     * other than "unbounded".
     *
     * @param limit the maximum value for maxOccurs other
     * than "unbounded"
     */
    public void setMaxOccurNodeLimit(int limit){
        maxOccurLimit = limit;
    }
    
    /**
     * Returns the limit of the number of content model nodes 
     * that may be created when building a grammar for a W3C 
     * XML Schema that contains maxOccurs attributes with values
     * other than "unbounded".
     *
     * @return the maximum value for maxOccurs other
     * than "unbounded"
     */ 
    public int getMaxOccurNodeLimit(){
        return maxOccurLimit;    
    }
    
} // class SecurityManager