(Android™) PKCS7 Sign Text using RSA 2048, SHA256, Base64 Output

Demonstrates how to sign text using 2048-bit RSA with SHA256, producing PKCS#7 output in Base64. The certificate w/ private key used for signing is loaded from a .p12/.pfx file.

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.

    CkCert cert = new CkCert();

    // Load the cert and private key.  Whatever the private key happens to be,
    // such as RSA or ECC, then Chilkat will use it.  If the private key is 
    // a 2048-bit RSA key, then that's what will be used..
    boolean success = cert.LoadPfxFile("qa_data/pfx/myCertAndKey.p12","password");
    if (success != true) {
        Log.i(TAG, cert.lastErrorText());
        return;
        }

    CkCrypt2 crypt = new CkCrypt2();

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

    // Use SHA-256
    crypt.put_HashAlgorithm("sha256");

    // Hash the utf-8 byte representation of the string
    crypt.put_Charset("utf-8");

    // Return the result in base64
    crypt.put_EncodingMode("base64");

    // Sign some text..
    String textToSign = "This is the text to be hashed and signed.";
    String sigBase64 = crypt.opaqueSignStringENC(textToSign);
    if (crypt.get_LastMethodSuccess() != true) {
        Log.i(TAG, crypt.lastErrorText());
        return;
        }

    Log.i(TAG, sigBase64);

    // The result:
    // MIIS2wYJKoZIhvcNAQc ... zGeeY4Oxg==

  }

  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."
  }
}