(Android™) Duplicate OpensSSL Command that Decrypts Binary DER

This example duplicates the following:

openssl smime -decrypt -in INPUT_FILE -inform der -binary -out OUTPUT_FILE -recip PEM_CERT_AND_KEY -passin pass:PRIVKEY_PASSWORD

Note: Although "smime" is the OpenSSL command, we're not really dealing with S/MIME. The arguments "-inform der -binary" indicate that the input is simply the binary DER (i.e. the PKCS7 binary encrypted object). The output can be any type of file (whatever was encrypted).

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();

    crypt.put_CryptAlgorithm("pki");

    CkPem pem = new CkPem();
    boolean success = pem.LoadPemFile("qa_data/pem/myPem.pem","password");
    if (success != true) {
        Log.i(TAG, pem.lastErrorText());
        return;
        }

    CkPrivateKey privkey = pem.GetPrivateKey(0);
    if (pem.get_LastMethodSuccess() != true) {
        Log.i(TAG, pem.lastErrorText());
        return;
        }

    CkCert cert = pem.GetCert(0);
    if (pem.get_LastMethodSuccess() != true) {

        Log.i(TAG, pem.lastErrorText());
        return;
        }

    success = crypt.SetDecryptCert2(cert,privkey);
    if (success != true) {

        Log.i(TAG, crypt.lastErrorText());
        return;
        }

    success = crypt.CkDecryptFile("qa_data/infile.enc","qa_output/outfile.dat");
    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."
  }
}