Android™

RSA Signature with Certificate's Private Key from PFX

See more RSA Examples

Demonstrates how to use a certificate's private key from a PFX file to create an RSA signature. 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.

    // Create an instance of a certificate store object, load a PFX file,
    // locate the certificate we need, and use it for signing.
    // (a PFX file may contain more than one certificate.)
    CkCertStore certStore = new CkCertStore();

    // The 1st argument is the filename, the 2nd arg is the 
    // PFX file's password:
    success = certStore.LoadPfxFile("chilkat.pfx","test");
    if (success == false) {
        Log.i(TAG, certStore.lastErrorText());
        return;
        }

    // Find the certificate by the subject common name:
    CkJsonObject jsonCN = new CkJsonObject();
    jsonCN.UpdateString("CN","cert common name");

    CkCert cert = new CkCert();
    success = certStore.FindCert(jsonCN,cert);
    if (success == false) {
        Log.i(TAG, certStore.lastErrorText());
        return;
        }

    CkPrivateKey privKey = new CkPrivateKey();
    success = cert.GetPrivateKey(privKey);
    if (success == false) {
        Log.i(TAG, cert.lastErrorText());
        return;
        }

    CkRsa rsa = new CkRsa();

    success = rsa.UsePrivateKey(privKey);
    if (success == false) {
        Log.i(TAG, rsa.lastErrorText());
        return;
        }

    // Encode the signature as a hex string
    rsa.put_EncodingMode("hex");

    String strData = "This is the string to be signed.";

    // Sign the string using the sha-1 hash algorithm.
    // Other valid choices are "sha-256", "md2" and "md5".
    String hexSig = rsa.signStringENC(strData,"sha-1");

    Log.i(TAG, hexSig);

    Log.i(TAG, "Success!");

  }

  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."
  }
}