(Android™) Verify and Unwrap PCKS7 Signed MIME

Demonstrates calling the Verify method to verify and unwrap PKCS7 signed MIME. The MIME is restored to the original structure that it would have originally had prior to signing. The Verify method works with both detached signatures, as well as opaque/attached signatures.

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

    CkMime mime = new CkMime();

    // A PKCS7 signature usually embeds both the signing
    // certificate with its public key.  Therefore, it is usually 
    // possible to verify a signature without the need to 
    // already have the certificate installed.

    // Load the signed MIME from a file...
    boolean success = mime.LoadMimeFile("signedMime.txt");
    if (success == false) {
        Log.i(TAG, mime.lastErrorText());
        return;
        }

    // Verify the signed MIME and restore the MIME
    // to the structure/content it had prior to signing.
    boolean verified;
    verified = mime.Verify();
    if (verified == false) {
        Log.i(TAG, mime.lastErrorText());
        return;
        }

    // Examine the MIME after signature verification (i.e. "unwrapping")
    Log.i(TAG, mime.getMime());

  }

  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."
  }
}