VerifySignature Method

Verifies signed XML.

Syntax

[VB.NET]
Public Sub VerifySignature()

[C#]
public void VerifySignature();

Remarks

This method verifies signatures contained in the XML.

When VerifySignature is called, the component will scan the XML document and fire the SignatureInfo event for each signature that is found. When the SignatureInfo event fires the References collection will be populated.

Within the SignatureInfo event the XMLElement field must be set to the location of the XML element to which the signature applies. The URI field may contain data helpful to locating the XML element.

The XMLElement field specifies the XPath to the element. For instance:


/root/myElement	XPath syntax
/root/[1]	XPath syntax using an index
/root/ns:myElement	XPath syntax where the element has a namespace
myElement	Just the element name
@id=myid	Attribute selector: This will select an element with an attribute "id" whose value is "myid".
/root/myElement[1]/ns:name2[@attr=attrValue]	XPath syntax using an index and attribute selector

The signature is verified either using a key parsed from the signed XML, or using the certificate specified by the SignerCert property. The component will automatically parse the signer certificate (if present) from the signed XML and populate the SignerCert property with the parsed value.

When SignatureInfo fires, if the SignerCertParsed parameter is True the SignerCert property may be inspected to see the details of the parsed certificate. If SignerCertParsed is False, then the SignerCert property must be set to a valid certificate for signature verification to proceed.

When the SignatureInfo event finishes firing, the certificate present in the SignerCert property will be used to verify the signature, whether this is the certificate automatically parsed by the component or a different certificate specified within the event.

If the signature was successfully verified the method will return without error. If the signature was not verified the method throws an exception.