Android™

CoSign PKCS7/CMS Signed Data

See more Digital Signatures Examples

Demonstrates how to add a 2nd signature to a CMS SignedData. This is to add an additional signature, SignerInfo and certificate(s) to an existing CMS signed data.

In this example, we cosign an existing pdf.p7s

Note: The CoSign method is added in Chilkat v9.5.0.89.

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();
    CkCert cert = new CkCert();

    // If loading from a smart card, set the smartcard PIN.
    cert.put_SmartCardPin("0000");

    // Load a certificate in some way, such as from a smart card.
    // Chilkat provides other methods to load from a .pfx, .pem, or from the Windows certificate stores..
    success = cert.LoadFromSmartcard("");
    if (success == false) {
        Log.i(TAG, cert.lastErrorText());
        return;
        }

    success = crypt.SetSigningCert(cert);
    if (success == false) {
        Log.i(TAG, crypt.lastErrorText());
        return;
        }

    // Load the file to be co-signed.
    // NOTE:  This is to cosign a PDF file contained within a CMS (PKCS7) message.
    // (In other words, the PDF is contained within the CMS SignedData, rather than the other way around
    // where a CMS signature is contained within a PDF.  Use Chilkat's PDF class to sign a PDF, which is
    // to embed a CMS signature within the PDF.)
    CkBinData bd = new CkBinData();
    success = bd.LoadFile("qa_data/p7s/cosign/sample.pdf.p7s");
    if (success == false) {
        Log.i(TAG, "Failed to load pdf.p7s input file.");
        return;
        }

    // bd2 will contain the co-signed result.
    CkBinData bd2 = new CkBinData();
    success = crypt.CoSign(bd,cert,bd2);
    if (success == false) {
        Log.i(TAG, crypt.lastErrorText());
        return;
        }

    success = bd.WriteFile("qa_output/cosigned.pdf.p7s");
    if (success == false) {
        Log.i(TAG, "Failed to save pdf.p7s output file.");
        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."
  }
}