Android™

Convert ASN.1 to/from Binary DER, XML, and Base64

Demonstrates how to convert ASN.1 from and to any of the following formats: binary DER, Base64, and XML. 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;

    CkAsn asn = new CkAsn();

    //  Begin with loading ASN.1 from a binary DER/BER format file.
    success = asn.LoadBinaryFile("/Users/chilkat/testData/p7b/test.p7b");
    if (success != true) {
        Log.i(TAG, asn.lastErrorText());
        return;
        }

    //  Convert ASN.1 to XML:
    String strXml = asn.asnToXml();
    if (asn.get_LastMethodSuccess() != true) {
        Log.i(TAG, asn.lastErrorText());
        return;
        }

    //  The XML returned by AsnToXml will be compact and not pretty-formatted.
    //  Use Chilkat XML to format the XML better:
    CkXml xml = new CkXml();
    success = xml.LoadXml(strXml);
    //  Assuming success for this example..
    //  This is formatted better for human viewing:
    Log.i(TAG, xml.getXml());

    //  Now get the ASN.1 in base64 format.  Any encoding supported
    //  by Chilkat can be passed, such as "hex", "uu", "quoted-printable", "base32", "modbase64", etc.
    String strBase64 = asn.getEncodedDer("base64");

    //  Load the ASN.1 from XML:
    CkAsn asn2 = new CkAsn();
    success = asn2.LoadAsnXml(xml.getXml());
    if (success != true) {
        Log.i(TAG, asn2.lastErrorText());
        return;
        }

    //  Load the ASN.1 from an encoded string, such as base64:
    CkAsn asn3 = new CkAsn();
    success = asn3.LoadEncoded(strBase64,"base64");
    if (success != true) {
        Log.i(TAG, asn3.lastErrorText());
        return;
        }


  }

  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."
  }
}