iaik.ixsil.core

Interface VerifierSignature

public interface VerifierSignature

This interface provides a specialized view a Signature. This view is used by the application in the signature verification use case.

See Also:

Verifier.getSignature()

Method Summary

Modifier and Type	Method and Description
void	computeDigestInputs() Computed the digest inputs for all references of this signature.
java.lang.String	getId() Gets the Id attribute value of the Signature element.
VerifierKeyManager	getKeyManager() Gets the key manager employed by IXSIL in the verification use case.
Object[]	getObjects() Gets all object containers which are part of this signature.
org.w3c.dom.Element	getSignatureDOMElement() Returns the DOM element of this XML signature structure; i.e.
VerifierSignedInfo	getVerifierSignedInfo() Gets an interface to the signed information object for the verification use case.
void	setKeyManager(VerifierKeyManager keyManager) Can be used by the application to set the key manager for the verification use case.
void	verify() Verifies this signature in a two step fashion: At first, for each reference in the signed information the digest will be produced over the referred data entity and compared against the digest value stored in the reference.

Method Detail

getId

java.lang.String getId()

Gets the Id attribute value of the Signature element.

Returns:

the attribute value or null if the Id attribute is not available.

getVerifierSignedInfo

VerifierSignedInfo getVerifierSignedInfo()

Gets an interface to the signed information object for the verification use case.

Returns:

an interface to the signed information object for the verification use case.

getObjects

Object[] getObjects()

Gets all object containers which are part of this signature.

Returns:

An Object array or null if there are no object containers available.

setKeyManager

void setKeyManager(VerifierKeyManager keyManager)

Can be used by the application to set the key manager for the verification use case. In most cases, this is not necessary, since IXSIL initializes a default key manager.

Parameters:

keyManager - The key manager to be used in the verification use case.

getKeyManager

VerifierKeyManager getKeyManager()
                          throws SignatureException

Gets the key manager employed by IXSIL in the verification use case. If there are no hints given in the signature in form of a KeyInfo element, and if the key manager object has not been set manually by the application, this method will return null.

Returns:

The VerifierKeyManager, or null if no key manager is currently employed.

Throws:

SignatureException - if instantiating the default key manager fails. This can happen if the application has not explicitly set a key manager, and IXSIL tries to set up the default key manager.

computeDigestInputs

void computeDigestInputs()
                  throws SignatureException

Computed the digest inputs for all references of this signature. This method can be invoked by the application when the signature has been configured completely, if the application needs access to the digest input of a reference of this signature.

The following example shows the necessary steps after the signature has been configured completely:

 VerifierSignature mySignature;
 ...
 mySignature.computeDigestInputs();
 VerifierSignedInfo mySignedInfo = mySignature.getVerifierSignedInfo();
 VerifierReference[] myReferences = mySignedInfo.getVerifierReferences();
 for (int i = 0; i < myReferences.length; i++)
 {
   java.io.InputStream explicitData =
     myReferences[i].getExplicitData(SignerReference.EXPLICITDATATYPE_DIGESTINPUT_);
 }
 ...
 mySignature.verify();
 

Throws:

SignatureException - if computing the digest input for one of the signature's references fails.

verify

void verify()
     throws SignatureException

Verifies this signature in a two step fashion: At first, for each reference in the signed information the digest will be produced over the referred data entity and compared against the digest value stored in the reference. Finally the signature over all the signed information will be verified.

Throws:

SignatureException - if digest verification fails for one of the signature's references, or if neither the verifcation key has been specified nor a KeyInfo element is present in the signature, or if verifying the signature fails, or if the signature cannot be verified for any other reason.

getSignatureDOMElement

org.w3c.dom.Element getSignatureDOMElement()

Returns the DOM element of this XML signature structure; i.e. the element with the name dsgi:Signature.

Returns:

The DOM element of this XML signature structure.