Android™

Load Certificate from Smart Card by Key Usage

See more Certificates Examples

You may have a smartcard or USB token that contains only 2 certificates, one for signing, and one for authentication, and you wish to load the certificate for signing. This example demonstrates how to load the 1st certificate found on a smartcard that matches the intended key usage. 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.

    CkCert cert = new CkCert();

    // If you know the smart card PIN, set it prior to loading from the smartcard/USB token.
    cert.put_SmartCardPin("12345678");

    // To load a certificate matching an intended key usage, specify the type of usage as shown below.
    // 
    // The possible key usage keywords are:
    // 
    // digitalsignature
    // Use when the public key is used with a digital signature mechanism to support security services other than non-repudiation, certificate signing, or CRL signing. 
    // A digital signature is often used for entity authentication and data origin authentication with integrity.

    // nonrepudiation
    // When a digital certificate's key usage includes "nonrepudiation," it implies that the certificate and its associated private key can be used to 
    // create digital signatures that provide proof of the origin and integrity of the signed data, and the signer cannot later deny having signed the data.

    // Other less common usages:

    // certificatesigning
    // keyencipherment
    // dataencipherment
    // crlsigning
    // secureemail
    // serverauthentication
    // clientauthentication
    // codesigning
    // timestamping

    success = cert.LoadFromSmartcard("keyusage=nonrepudiation");
    if (success == false) {
        Log.i(TAG, cert.lastErrorText());
        Log.i(TAG, "Certificate not loaded.");
        return;
        }

    Log.i(TAG, "Found: " + cert.subjectDN() + " serial=" + cert.serialNumber());

  }

  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."
  }
}