(Visual FoxPro) Verify XAdES with External File Reference

Demonstrates how to validate an XML digital signature that contains a reference to an external file. (This is one way of doing it..)

Chilkat ActiveX Downloads ActiveX for 32-bit and 64-bit Windows

LOCAL loSbXml
LOCAL lnSuccess
LOCAL loValidator
LOCAL i
LOCAL lnValid

* This example requires the Chilkat API to have been previously unlocked.
* See Global Unlock Sample for sample code.

* Load the XAdES file to be validated..
* For versions of Chilkat < 10.0.0, use CreateObject('Chilkat_9_5_0.StringBuilder')
loSbXml = CreateObject('Chilkat.StringBuilder')
lnSuccess = loSbXml.LoadFile("qa_data/xml_dsig_valid_samples/externalFile/test.pdf.XAdES","utf-8")
IF (lnSuccess = 0) THEN
    ? "Failed to load XAdES input file."
    RELEASE loSbXml
    CANCEL
ENDIF

* For versions of Chilkat < 10.0.0, use CreateObject('Chilkat_9_5_0.XmlDSig')
loValidator = CreateObject('Chilkat.XmlDSig')

* Specify a set of absolute or relative directory paths to be searched for any external file references.
* Directory paths are separated by semicolon chars.
loValidator.ExternalRefDirs = "qa_data/externalFiles;qa_data/xml_dsig_valid_samples/externalFile;c:/someOtherDir"

lnSuccess = loValidator.LoadSignatureSb(loSbXml)
IF (lnSuccess = 0) THEN
    ? loValidator.LastErrorText
    RELEASE loSbXml
    RELEASE loValidator
    CANCEL
ENDIF

* Validate signatures as usual..
i = 0
DO WHILE i < loValidator.NumSignatures
    loValidator.Selector = i

    lnValid = loValidator.VerifySignature(1)
    ? "Signature " + STR(i + 1) + " and all reference digests OK = " + STR(lnValid)

    i = i + 1
ENDDO

RELEASE loSbXml
RELEASE loValidator