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SecurityManager.javaAPI DocJava SE 5 API7818Fri Aug 26 14:55:56 BST 2005com.sun.org.apache.xerces.internal.util

SecurityManager

public final class SecurityManager extends Object
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,v 1.5 2004/03/23 01:23:41 mrglavas Exp $

Fields Summary
private static final int
DEFAULT_ENTITY_EXPANSION_LIMIT
private static final int
DEFAULT_MAX_OCCUR_NODE_LIMIT
Default value of number of nodes created.
private static final int
DEFAULT_ELEMENT_ATTRIBUTE_LIMIT
private int
entityExpansionLimit
Entity expansion limit.
private int
maxOccurLimit
W3C XML Schema maxOccurs limit.
private int
fElementAttributeLimit
Constructors Summary
public SecurityManager()
Default constructor. Establishes default values for known security vulnerabilities.

    // default constructor.  Establishes default values for
    // all known security holes.  
                      
      
        entityExpansionLimit = DEFAULT_ENTITY_EXPANSION_LIMIT;
        maxOccurLimit = DEFAULT_MAX_OCCUR_NODE_LIMIT ;
		fElementAttributeLimit = DEFAULT_ELEMENT_ATTRIBUTE_LIMIT;
		//We are reading system properties only once ,
		//at the time of creation of this object ,
		readSystemProperties();
Methods Summary
public intgetElementAttrLimit()

		return fElementAttributeLimit;
public intgetEntityExpansionLimit()

Returns the number of entity expansions that the parser permits in a document.

return
the number of entity expansions permitted in a document

        return entityExpansionLimit;
public intgetMaxOccurNodeLimit()

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"

        return maxOccurLimit;
private voidreadSystemProperties()


		//TODO:	also read SYSTEM_PROPERTY_ELEMENT_ATTRIBUTE_LIMIT
		try {
			String value = System.getProperty(Constants.ENTITY_EXPANSION_LIMIT);
			if(value != null && !value.equals("")){
				entityExpansionLimit = Integer.parseInt(value);
				if (entityExpansionLimit < 0)
					entityExpansionLimit = DEFAULT_ENTITY_EXPANSION_LIMIT;
			}
			else
				entityExpansionLimit = DEFAULT_ENTITY_EXPANSION_LIMIT;
		}catch(Exception ex){}

		try {
			String value = System.getProperty(Constants.MAX_OCCUR_LIMIT);
			if(value != null && !value.equals("")){
				maxOccurLimit = Integer.parseInt(value);
				if (maxOccurLimit < 0)
					maxOccurLimit = DEFAULT_MAX_OCCUR_NODE_LIMIT;
			}
			else
				maxOccurLimit = DEFAULT_MAX_OCCUR_NODE_LIMIT;
		}catch(Exception ex){}

		try {
			String value = System.getProperty(Constants.SYSTEM_PROPERTY_ELEMENT_ATTRIBUTE_LIMIT);
			if(value != null && !value.equals("")){
				fElementAttributeLimit = Integer.parseInt(value);
				if ( fElementAttributeLimit < 0)
					fElementAttributeLimit = DEFAULT_ELEMENT_ATTRIBUTE_LIMIT;
			}
			else
				fElementAttributeLimit = DEFAULT_ELEMENT_ATTRIBUTE_LIMIT;

		}catch(Exception ex){}
public voidsetElementAttrLimit(int limit)

 
		fElementAttributeLimit = limit;
public voidsetEntityExpansionLimit(int 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

        entityExpansionLimit = limit;
public voidsetMaxOccurNodeLimit(int limit)

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"

        maxOccurLimit = limit;