Java

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). Chilkat2 Java

import com.chilkatsoft.chilkat2.Asn;
import com.chilkatsoft.chilkat2.BinData;
import com.chilkatsoft.chilkat2.ChilkatException;
import com.chilkatsoft.chilkat2.Xml;

public class ChilkatExample {

    public static void main(String[] args) {
        // 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
        BinData bdTsr = new BinData();
        try {
            bdTsr.loadFile("qa_data/tsd/sample.tsr");
        } catch (ChilkatException e) {
            System.out.println("Failed to load timestamp reply file.");
            return;
        }

        // Load the tsr into an ASN.1 object.
        Asn asnTsr = new Asn();
        try {
            asnTsr.loadEncoded(bdTsr.getEncoded("base64"), "base64");
        } catch (ChilkatException e) {
            System.out.println(e.getLastErrorText());
            return;
        }

        // Get the timestamp reply as XML.
        Xml xmlTsr = new Xml();
        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..
        BinData bdContent = new BinData();
        try {
            bdContent.loadFile("qa_data/tsd/sample.p7m");
        } catch (ChilkatException e) {
            System.out.println("Failed to load content file.");
            return;
        }

        // Begin building the TimeStampData.
        // We'll build as XML and then convert to ASN.1
        Xml xml = new Xml();
        xml.setTag("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");

        Xml xContext = xml.getChildWithTag("contextSpecific|sequence|contextSpecific");
        xContext.addChildTree(xmlTsr);
        xContext.close();

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

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

        // Alternatively, get the tsd ASN.1 as base64..
        String tsdBase64 = tsd.getEncodedDer("base64_mime");
        System.out.println(tsdBase64);
    }
}