(C#) Verify XML Digital Signature

Verifies XML signatures in an XML file.

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

Chilkat.StringBuilder sbXml = new Chilkat.StringBuilder();
bool success = sbXml.LoadFile("qa_data/xml_dsig_verify/csioz_sample.xml","utf-8");
if (success != true) {
    Debug.WriteLine("Failed to load XML file.");
    return;
}

Chilkat.XmlDSig dsig = new Chilkat.XmlDSig();

// First load the XML containing the signatures to be verified.
success = dsig.LoadSignatureSb(sbXml);
if (success != true) {
    Debug.WriteLine(dsig.LastErrorText);
    return;
}

// It's possible that an XML document can contain multiple signatures.
// Each can be verified as follows:
int i = 0;
while (i < dsig.NumSignatures) {
    // Select the Nth signature by setting the Selector property.
    dsig.Selector = i;

    // The bVerifyReferenceDigests argument determines if we want
    // to also verify each reference digest.  If set to false,
    // then only the SignedInfo part of the Signature is verified.
    bool bVerifyReferenceDigests = true;
    bool bVerified = dsig.VerifySignature(bVerifyReferenceDigests);
    Debug.WriteLine("Signature " + Convert.ToString(i + 1) + " verified = " + Convert.ToString(bVerified));

    i = i + 1;
}