React Native

Add EncapsulatedTimestamp to Already-Signed XML

See more XML Digital Signatures Examples

Demonstrates how to add an EncapsulatedTimestamp to an existing XML signature.

Note: This example requires Chilkat v9.5.0.90 or greater.

React Native

import { JsonObject, StringBuilder, XmlDSig } from '@chilkat/react-native'

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

  // Note: We cannot load the already-signed XML into a Chilkat XML object because it would re-format the XML when re-emitted.
  // (i.e. indentation and whitespace could change, and it would invalidate the existing signature.)
  // We must use a StringBuilder.
  const sbXml = new StringBuilder();
  try {
    sbXml.loadFile('qa_data/xml_dsig_valid_samples/encapsulatedTimestamp_not_yet_added.xml', 'utf-8');
  } catch {
    console.log('Failed to load the XML file.');
    return;
  }

  const dsig = new XmlDSig();
  try {
    dsig.loadSignatureSb(sbXml);
  } catch {
    console.log(dsig.lastErrorText);
    return;
  }

  if (dsig.hasEncapsulatedTimeStamp()) {
    console.log('This signed XML already has an EncapsulatedTimeStamp');
    return;
  }

  // Specify the timestamping authority URL
  const json = new JsonObject();
  json.updateString('timestampToken.tsaUrl', 'http://timestamp.digicert.com');
  json.updateBool('timestampToken.requestTsaCert', true);

  // Call AddEncapsulatedTimeStamp to add the EncapsulatedTimeStamp to the signature.
  // Note: If the signed XML contains multiple signatures, the signature modified is the one 
  // indicated by the dsig.Selector property.
  const sbOut = new StringBuilder();
  try {
    dsig.addEncapsulatedTimeStamp(json, sbOut);
  } catch {
    console.log(dsig.lastErrorText);
    return;
  }

  sbOut.writeFile('qa_output/addedEncapsulatedTimeStamp.xml', 'utf-8', false);

  // The EncapsulatedTimeStamp can be validated when validating the signature by adding the VerifyEncapsulatedTimeStamp
  // keyword to UncommonOptions.  See here:

  // ----------------------------------------
  // Verify the signatures we just produced...
  const verifier = new XmlDSig();
  try {
    verifier.loadSignatureSb(sbOut);
  } catch {
    console.log(verifier.lastErrorText);
    return;
  }

  // Add "VerifyEncapsulatedTimeStamp" to the UncommonOptions to also verify any EncapsulatedTimeStamps
  verifier.uncommonOptions = 'VerifyEncapsulatedTimeStamp';

  const numSigs = verifier.numSignatures;
  let verifyIdx = 0;
  while (verifyIdx < numSigs) {
    verifier.selector = verifyIdx;
    try {
      verifier.verifySignature(true);
    } catch {
      console.log(verifier.lastErrorText);
      return;
    }

    verifyIdx++;
  }

  console.log('All signatures were successfully verified.');
}