SignatureInfo Event
Fired when a signature is found.
Syntax
type TSignatureInfoEvent = procedure ( Sender: TObject; const SignatureId: String; SignerCertParsed: Boolean ) of Object;
property OnSignatureInfo: TSignatureInfoEvent read FOnSignatureInfo write FOnSignatureInfo;
Remarks
This event fires when calling VerifySignature for each signature found within the XML document.
SignatureId is the id of the signature.
SignerCertParsed indicates whether the signer's certificate was automatically parsed from the signed XML.
Verification Notes
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 Reference* properties will be populated.
Within the SignatureInfo event the XMLElement property must be set to the location of the XML element to which the signature applies. The URI property may contain data helpful to locating the XML element.
The XMLElement property 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* properties. The component will automatically parse the signer certificate (if present) from the signed XML and populate the SignerCert* properties with the parsed value.
When SignatureInfo fires, if the SignerCertParsed parameter is True the SignerCert* properties may be inspected to see the details of the parsed certificate. If SignerCertParsed is False, then the SignerCert* properties must be set to a valid certificate for signature verification to proceed.
When the SignatureInfo event finishes firing, the certificate present in the SignerCert* properties 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 raises an exception.