(Android™) 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.

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// Important: Don't forget to include the call to System.loadLibrary
// as shown at the bottom of this code sample.
package com.test;

import android.app.Activity;
import com.chilkatsoft.*;

import android.widget.TextView;
import android.os.Bundle;

public class SimpleActivity extends Activity {

  private static final String TAG = "Chilkat";

  // Called when the activity is first created.
  @Override
  public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);

    // 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.
    CkStringBuilder sbXml = new CkStringBuilder();
    boolean success = sbXml.LoadFile("qa_data/xml_dsig_valid_samples/encapsulatedTimestamp_not_yet_added.xml","utf-8");
    if (success == false) {
        Log.i(TAG, "Failed to load the XML file.");
        return;
        }

    CkXmlDSig dsig = new CkXmlDSig();
    success = dsig.LoadSignatureSb(sbXml);
    if (success == false) {
        Log.i(TAG, dsig.lastErrorText());
        return;
        }

    if (dsig.HasEncapsulatedTimeStamp() == true) {
        Log.i(TAG, "This signed XML already has an EncapsulatedTimeStamp");
        return;
        }

    // Specify the timestamping authority URL
    CkJsonObject json = new CkJsonObject();
    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.
    CkStringBuilder sbOut = new CkStringBuilder();
    success = dsig.AddEncapsulatedTimeStamp(json,sbOut);
    if (success == false) {
        Log.i(TAG, 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...
    CkXmlDSig verifier = new CkXmlDSig();
    success = verifier.LoadSignatureSb(sbOut);
    if (success != true) {
        Log.i(TAG, verifier.lastErrorText());
        return;
        }

    // Add "VerifyEncapsulatedTimeStamp" to the UncommonOptions to also verify any EncapsulatedTimeStamps
    verifier.put_UncommonOptions("VerifyEncapsulatedTimeStamp");

    int numSigs = verifier.get_NumSignatures();
    int verifyIdx = 0;
    while (verifyIdx < numSigs) {
        verifier.put_Selector(verifyIdx);
        boolean verified = verifier.VerifySignature(true);
        if (verified != true) {
            Log.i(TAG, verifier.lastErrorText());
            return;
            }

        verifyIdx = verifyIdx + 1;
        }

    Log.i(TAG, "All signatures were successfully verified.");

  }

  static {
      System.loadLibrary("chilkat");

      // Note: If the incorrect library name is passed to System.loadLibrary,
      // then you will see the following error message at application startup:
      //"The application <your-application-name> has stopped unexpectedly. Please try again."
  }
}