(Android™) Duplicate OpensSSL to Create Signature using Cert and Key Files

This example duplicates the following:

openssl smime –sign -in something.xml -out something.der -signer mycert.crt -inkey cert.key -outform der –nodetach

Note: Although "smime" is the OpenSSL command, it's not actually producing S/MIME. The arguments "-outform der -binary" indicates that the output is binary DER (i.e. the PKCS7 binary signature). The input can be any type of file: XML, PDF, JPG, ... *anything*...

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.

    CkCrypt2 crypt = new CkCrypt2();

    // Load the cert and private key from separate files.
    CkCert cert = new CkCert();
    boolean success = cert.LoadFromFile("myCert.crt");
    if (success != true) {
        Log.i(TAG, cert.lastErrorText());
        return;
        }

    CkBinData bd = new CkBinData();
    success = bd.LoadFile("cert.key");
    CkPrivateKey privkey = new CkPrivateKey();
    // Load from any format private key.
    // If the file does not need a password, the 2nd arg is ignored.
    success = privkey.LoadAnyFormat(bd,"password_if_needed");
    if (success != true) {
        Log.i(TAG, privkey.lastErrorText());
        return;
        }

    success = crypt.SetSigningCert2(cert,privkey);
    if (success != true) {
        Log.i(TAG, crypt.lastErrorText());
        return;
        }

    // Create the opaque signature (PKCS7 binary DER that contains both the signature and original file data).
    success = crypt.CreateP7M("qa_data/infile.anything","qa_output/outfile.der");
    if (success != true) {
        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."
  }
}