Class DefaultSafeXmlParserFactory

java.lang.Object

com.itextpdf.kernel.utils.DefaultSafeXmlParserFactory

All Implemented Interfaces:

IXmlParserFactory

public class DefaultSafeXmlParserFactory
extends Object
implements IXmlParserFactory

Implementation of IXmlParserFactory for creating safe xml parser objects. Creates parsers with configuration to prevent XML bombs and XXE attacks.

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
private static class	DefaultSafeXmlParserFactory.SafeEmptyEntityResolver

Field Summary

Fields

Modifier and Type	Field	Description
private static final String	DISALLOW_DOCTYPE_DECL	Feature for disallowing DOCTYPE declaration.
private static final String	EXTERNAL_GENERAL_ENTITIES	If you can't disable DOCTYPE declarations, then at least disable external entities.
private static final String	EXTERNAL_PARAMETER_ENTITIES	Must be used with the EXTERNAL_GENERAL_ENTITIES, otherwise has no effect.
private static final String	LOAD_EXTERNAL_DTD	Disable external DTDs.
private static final org.slf4j.Logger	LOGGER

Constructor Summary

Constructors

Constructor	Description
DefaultSafeXmlParserFactory()	Creates instance of DefaultSafeXmlParserFactory.

Method Summary

Modifier and Type	Method	Description
protected void	configureSafeDocumentBuilderFactory(DocumentBuilderFactory factory)	Configures document builder factory to make it secure against xml attacks.
protected void	configureSafeSAXParserFactory(SAXParserFactory factory)	Configures SAX parser factory to make it secure against xml attacks.
protected void	configureSafeTransformerFactory(TransformerFactory factory)	Configures transformer factory to make it secure against xml attacks.
protected DocumentBuilderFactory	createDocumentBuilderFactory()	Creates a document builder factory implementation.
DocumentBuilder	createDocumentBuilderInstance(boolean namespaceAware, boolean ignoringComments)	Creates the instance of the DocumentBuilder.
protected SAXParserFactory	createSAXParserFactory()	Creates a SAX parser factory implementation.
Transformer	createTransformerInstance()	Creates the instance of the Transformer.
XMLReader	createXMLReaderInstance(boolean namespaceAware, boolean validating)	Creates the instance of the XMLReader.
private void	tryToSetFeature(DocumentBuilderFactory factory, String feature, boolean value)
private void	tryToSetFeature(SAXParserFactory factory, String feature, boolean value)

Methods inherited from class Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Details

LOGGER

private static final org.slf4j.Logger LOGGER

DISALLOW_DOCTYPE_DECL

private static final String DISALLOW_DOCTYPE_DECL

Feature for disallowing DOCTYPE declaration.

Xerces 2 only - http://xerces.apache.org/xerces2-j/features.html#disallow-doctype-decl

See Also:

• Constant Field Values

EXTERNAL_GENERAL_ENTITIES

private static final String EXTERNAL_GENERAL_ENTITIES

If you can't disable DOCTYPE declarations, then at least disable external entities. Must be used with the EXTERNAL_PARAMETER_ENTITIES, otherwise has no effect.

Xerces 1 - http://xerces.apache.org/xerces-j/features.html#external-general-entities Xerces 2 - http://xerces.apache.org/xerces2-j/features.html#external-general-entities JDK7+ - http://xml.org/sax/features/external-general-entities

See Also:

• Constant Field Values

EXTERNAL_PARAMETER_ENTITIES

private static final String EXTERNAL_PARAMETER_ENTITIES

Must be used with the EXTERNAL_GENERAL_ENTITIES, otherwise has no effect.

Xerces 1 - http://xerces.apache.org/xerces-j/features.html#external-parameter-entities Xerces 2 - http://xerces.apache.org/xerces2-j/features.html#external-parameter-entities JDK7+ - http://xml.org/sax/features/external-parameter-entities

See Also:

• Constant Field Values

LOAD_EXTERNAL_DTD

private static final String LOAD_EXTERNAL_DTD

Disable external DTDs.

See Also:

• Constant Field Values

Constructor Details

DefaultSafeXmlParserFactory

public DefaultSafeXmlParserFactory()

Creates instance of DefaultSafeXmlParserFactory.

Method Details

createDocumentBuilderInstance

public DocumentBuilder createDocumentBuilderInstance(boolean namespaceAware,
 boolean ignoringComments)

Description copied from interface: IXmlParserFactory

Creates the instance of the DocumentBuilder.

Specified by:

createDocumentBuilderInstance in interface IXmlParserFactory

Parameters:

namespaceAware - specifies whether the parser should be namespace aware

ignoringComments - specifies whether the parser should ignore comments

Returns:

instance of the DocumentBuilder

createXMLReaderInstance

public XMLReader createXMLReaderInstance(boolean namespaceAware,
 boolean validating)

Description copied from interface: IXmlParserFactory

Creates the instance of the XMLReader.

Specified by:

createXMLReaderInstance in interface IXmlParserFactory

Parameters:

namespaceAware - specifies whether the parser should be namespace aware

validating - specifies whether the parser should validate documents as they are parsed

Returns:

instance of the XMLReader

createTransformerInstance

public Transformer createTransformerInstance()

Description copied from interface: IXmlParserFactory

Creates the instance of the Transformer.

Specified by:

createTransformerInstance in interface IXmlParserFactory

Returns:

instance of the Transformer

createDocumentBuilderFactory

protected DocumentBuilderFactory createDocumentBuilderFactory()

Creates a document builder factory implementation.

Returns:

result of DocumentBuilderFactory.newInstance() call

createSAXParserFactory

protected SAXParserFactory createSAXParserFactory()

Creates a SAX parser factory implementation.

Returns:

result of SAXParserFactory.newInstance() call

configureSafeDocumentBuilderFactory

protected void configureSafeDocumentBuilderFactory(DocumentBuilderFactory factory)

Configures document builder factory to make it secure against xml attacks.

Parameters:

factory - DocumentBuilderFactory instance to be configured

configureSafeSAXParserFactory

protected void configureSafeSAXParserFactory(SAXParserFactory factory)

Configures SAX parser factory to make it secure against xml attacks.

Parameters:

factory - SAXParserFactory instance to be configured

configureSafeTransformerFactory

protected void configureSafeTransformerFactory(TransformerFactory factory)

Configures transformer factory to make it secure against xml attacks.

Parameters:

factory - TransformerFactory instance to be configured

tryToSetFeature

private void tryToSetFeature(DocumentBuilderFactory factory,
 String feature,
 boolean value)

tryToSetFeature

private void tryToSetFeature(SAXParserFactory factory,
 String feature,
 boolean value)