Android™

Combine Timestamp Reply and Content File into a TimeStampData

See more ASN.1 Examples

Demonstrates how to combine a timestamp reply (RFC 3161) with a data file (any type of file) to create a TimeStampData structure (RFC 5544). Android™

// 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);

    boolean success = false;

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

    // Also see this example:
    // Send a TimeStamp Request to a TimeStamp Authority and get the Response

    // Load a timestamp reply file
    CkBinData bdTsr = new CkBinData();
    success = bdTsr.LoadFile("qa_data/tsd/sample.tsr");
    if (success != true) {
        Log.i(TAG, "Failed to load timestamp reply file.");
        return;
        }

    // Load the tsr into an ASN.1 object.
    CkAsn asnTsr = new CkAsn();
    success = asnTsr.LoadEncoded(bdTsr.getEncoded("base64"),"base64");
    if (success != true) {
        Log.i(TAG, asnTsr.lastErrorText());
        return;
        }

    // Get the timestamp reply as XML.
    CkXml xmlTsr = new CkXml();
    xmlTsr.LoadXml(asnTsr.asnToXml());

    // The timestamp reply XML begins like this:
    // We'll want to remove the 1st "sequence" subtree.

    //     <?xml version="1.0" encoding="utf-8"?>
    //     <sequence>
    //         <sequence>       <---- Remove this sub-tree.
    //             <int>00</int>
    //             <sequence>
    //                 <utf8>Operation Okay</utf8>
    //             </sequence>
    //         </sequence>
    //         <sequence>   
    //             <oid>1.2.840.113549.1.7.2</oid>
    //             <contextSpecific tag="0" constructed="1">
    //             ...

    // Remove the 1st sub-tree..
    xmlTsr.RemoveChildByIndex(0);

    // In this example, the data file we're combining with the timestamp into a timestampData is a .p7m.
    // However, it can be any type of file (text or binary), it doesn't matter..
    CkBinData bdContent = new CkBinData();
    success = bdContent.LoadFile("qa_data/tsd/sample.p7m");
    if (success != true) {
        Log.i(TAG, "Failed to load content file.");
        return;
        }

    // Begin building the TimeStampData.  
    // We'll build as XML and then convert to ASN.1
    CkXml xml = new CkXml();
    xml.put_Tag("sequence");
    xml.UpdateChildContent("oid","1.2.840.113549.1.9.16.1.31");
    xml.UpdateAttrAt("contextSpecific",true,"tag","0");
    xml.UpdateAttrAt("contextSpecific",true,"constructed","1");
    xml.UpdateChildContent("contextSpecific|sequence|int","01");
    xml.UpdateChildContent("contextSpecific|sequence|octets",bdContent.getEncoded("base64"));
    xml.UpdateAttrAt("contextSpecific|sequence|contextSpecific",true,"tag","0");
    xml.UpdateAttrAt("contextSpecific|sequence|contextSpecific",true,"constructed","1");

    CkXml xContext = xml.GetChildWithTag("contextSpecific|sequence|contextSpecific");
    xContext.AddChildTree(xmlTsr);

    // Convert the XML to ASN.1
    CkAsn tsd = new CkAsn();
    tsd.LoadAsnXml(xml.getXml());

    // Write the timestamped data to a file.
    success = tsd.WriteBinaryDer("qa_output/sample.tsd");

    // Alternatively, get the tsd ASN.1 as base64..
    String tsdBase64 = tsd.getEncodedDer("base64_mime");
    Log.i(TAG, tsdBase64);

  }

  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."
  }
}