javax.xml.crypto.dsig
interface Reference

All Superinterfaces:

XMLStructure

public interface Reference
extends XMLStructure

A representation of the Reference element as defined in the W3C Recommendation for XML-Signature Syntax and Processing. The XML schema is defined as:

 <element name="Reference" type="ds:ReferenceType"/>
 <complexType name="ReferenceType">
   <sequence>
     <element ref="ds:Transforms" minOccurs="0"/>
     <element ref="ds:DigestMethod"/>
     <element ref="ds:DigestValue"/>
   </sequence>
   <attribute name="Id" type="ID" use="optional"/>
   <attribute name="URI" type="anyURI" use="optional"/>
   <attribute name="Type" type="anyURI" use="optional"/>
 </complexType>

 <element name="DigestValue" type="ds:DigestValueType"/>
 <simpleType name="DigestValueType">
   <restriction base="base64Binary"/>
 </simpleType>
 

A Reference instance may be created by invoking one of the {@link XMLSignatureFactory#newReference newReference} methods of the {@link XMLSignatureFactory} class; for example:

   XMLSignatureFactory factory = XMLSignatureFactory.getInstance("DOM");
   Reference ref = factory.newReference
     ("http://www.ietf.org/rfc/rfc3275.txt", 
	factory.newDigestMethod(DigestMethod.SHA1, null));
 

getCalculatedDigestValue

public byte[] getCalculatedDigestValue()

Returns the calculated digest value of this Reference after a validation operation. This method is useful for debugging if the reference fails to validate.

Returns:

the calculated digest value, or null if this reference has not been validated yet. Each invocation of this method returns a new clone to protect against subsequent modification.

getDereferencedData

public Data getDereferencedData()

Returns the dereferenced data, if reference caching is enabled. This is the result of dereferencing the URI of this reference during a validation or generation operation.

Returns:

the dereferenced data, or null if reference caching is not enabled or this reference has not been generated or validated

getDigestInputStream

public InputStream getDigestInputStream()

Returns the pre-digested input stream, if reference caching is enabled. This is the input to the digest operation during a validation or signing operation.

Returns:

an input stream containing the pre-digested input, or null if reference caching is not enabled or this reference has not been generated or validated

getDigestMethod

public DigestMethod getDigestMethod()

Returns the digest method of this Reference.

Returns:

the digest method

getDigestValue

public byte[] getDigestValue()

Returns the digest value of this Reference.

Returns:

the raw digest value, or null if this reference has not been digested yet. Each invocation of this method returns a new clone to protect against subsequent modification.

getId

public String getId()

Returns the optional Id attribute of this Reference, which permits this reference to be referenced from elsewhere.

Returns:

the Id attribute (may be null if not specified)

getTransforms

public List getTransforms()

Returns an {@link java.util.Collections#unmodifiableList unmodifiable list} of {@link Transform}s that are contained in this Reference.

Returns:

an unmodifiable list of Transforms (may be empty but never null)

validate

public boolean validate(XMLValidateContext validateContext)
                 throws XMLSignatureException

Validates this reference. This method verifies the digest of this reference.

This method only validates the reference the first time it is invoked. On subsequent invocations, it returns a cached result.

Parameters:

validateContext - the validating context

Returns:

true if this reference was validated successfully; false otherwise

Throws:

XMLSignatureException - if an unexpected exception occurs while validating the reference