Android™

Create CMS Signed File (PDF) with Multiple Signing Certificates

See more Digital Signatures Examples

Demonstrates how to sign a file by adding multiple signatures (multiple certificates). This example signs a PDF file to produce an output file that is a CMS signature wrapping the original PDF. (Note: This is different than modifying a PDF by injecting a signature into the PDF file format.)

Note: This example requires Chilkat v9.5.0.83 or greater.

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

    CkCrypt2 crypt = new CkCrypt2();

    // ------------ This example requires Chilkat v9.5.0.83 or greater.

    CkCert cert1 = new CkCert();
    success = cert1.LoadPfxFile("qa_data/pfx/cert_test123.pfx","test123");
    if (success != true) {
        Log.i(TAG, cert1.lastErrorText());
        return;
        }

    CkCert cert2 = new CkCert();
    success = cert2.LoadPfxFile("qa_data/pfx/test_secret.pfx","secret");
    if (success != true) {
        Log.i(TAG, cert2.lastErrorText());
        return;
        }

    // ------------ This example requires Chilkat v9.5.0.83 or greater.

    // Tell the crypt component to use both certificates for signing. 
    // When we create the signature, it will be signed by both certificates.
    success = crypt.AddSigningCert(cert1);
    if (success != true) {
        Log.i(TAG, crypt.lastErrorText());
        return;
        }

    success = crypt.AddSigningCert(cert2);
    if (success != true) {
        Log.i(TAG, crypt.lastErrorText());
        return;
        }

    // The CadesEnabled property applies to all methods that create PKCS7 signatures. 
    // To create a CAdES-BES signature, set this property equal to true. 
    crypt.put_CadesEnabled(true);

    crypt.put_HashAlgorithm("sha256");

    // We can sign any type of file, creating a .p7s as output.
    // The .p7s contains the signature and also embeds the data of the file that is signed.
    String inFile = "qa_data/pdf/sample.pdf";
    String p7sFile = "qa_output/sample.pdf.p7s";

    // Create the CAdES-BES attached signature, which contains the original data.
    // Note: Chilkat's function naming is not accurate.  CreateP7M creates a PKCS7 signature where the signed file
    // is contained within the signature.  CreateP7S creates a detached PKCS7 signature where the signed file
    // is NOT contained within the signature.  We want the data to be contained in the signature, therefore
    // we call CreateP7M even though we are naming our output file .p7s.
    success = crypt.CreateP7M(inFile,p7sFile);
    if (success == false) {
        Log.i(TAG, crypt.lastErrorText());
        return;
        }

    // Verify the .p7s file and extract the original file from the .p7s. 
    String extractedToFilePath = "qa_output/sample.pdf";
    success = crypt.VerifyP7M(p7sFile,extractedToFilePath);
    if (success == false) {
        Log.i(TAG, crypt.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."
  }
}