(Android™) ConvertToSignedPk

Demonstrates how to digitally sign MIME to create an "opaque" signature. The MIME is converted to an application/x-pkcs7-mime which is a PKCS7 signature that includes both the original MIME message and the signature. This is different than AddDetachedSignaturePk, where the signature is appended to the MIME. This example demonstrates how to use the certificate and its corresponding private key when they are stored in separate files -- a .cer for the certificate, and a .pem for the private key.

Chilkat Android™ Downloads Android™ Java Libraries Android C/C++ Libraries

// 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);

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

    CkMime mime = new CkMime();

    // Load the certificate from a .cer file.
    CkCert cert = new CkCert();
    boolean success = cert.LoadFromFile("aaworkarea/myCert.cer");
    if (success == false) {
        Log.i(TAG, cert.lastErrorText());
        return;
        }

    // Load the private key from an encrypted PEM file.
    // (A private key can be loaded from other file formats also..)
    CkPrivateKey privKey = new CkPrivateKey();
    success = privKey.LoadEncryptedPemFile("aaworkarea/myPrivateKey.pem","myPassword");
    if (success == false) {
        Log.i(TAG, privKey.lastErrorText());
        return;
        }

    success = mime.SetBodyFromPlainText("This is the plain-text MIME body.");

    // Convert the MIME to application/x-pkcs7-mime, which
    // is PKCS7 containing both the original content and the signature.
    success = mime.ConvertToSignedPk(cert,privKey);
    if (success == false) {
        Log.i(TAG, mime.lastErrorText());
        return;
        }

    // Save the S/MIME to a file.
    success = mime.SaveMime("aaworkarea/opaqueSignedMime.txt");
    if (success == false) {
        Log.i(TAG, mime.lastErrorText());
        return;
        }

    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."
  }
}