Android™

Convert Let's Encrypt PEM Files to a PFX

See more PFX/P12 Examples

Demonstrates how to convert the .pem files provided by Let's Encrypt to a single PFX. 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.

    //  Let's Encrypt provides four .pem files
    //  1. fullchain.pem
    //  2. privkey.pem
    //  3. cert.pem
    //  4. chain.pem

    //  The cert.pem and chain.pem are redundant. 
    //  The fullchain.pem is composed of the cert.pem and chain.pem.

    //  To convert the PEM's to a single .pfx, we don't need the redundant data.
    //  The privkey.pem and fullchain.pem provide the required data.
    //  We can ignore cert.pem and chain.pem (because those certs are already found in fullchain.pem).

    //  We need a single .pem file that contains both the private key, the cert,
    //  and the certs in the chain of authentication.
    //  Let's combine priveky.pem and fullchain.pem into a single .pem

    CkStringBuilder sbPem = new CkStringBuilder();
    success = sbPem.LoadFile("qa_data/pem/lets_encrypt/privkey.pem","utf-8");
    if (success == false) {
        Log.i(TAG, "Failed to load privkey.pem");
        return;
        }

    //  To be safe, append a blank line..
    sbPem.AppendLine("",false);

    CkStringBuilder sbFullChainPem = new CkStringBuilder();
    success = sbFullChainPem.LoadFile("qa_data/pem/lets_encrypt/fullchain.pem","utf-8");
    if (success == false) {
        Log.i(TAG, "Failed to load fullchain.pem");
        return;
        }

    //  Append the full cert chain PEM to the private key PEM.
    sbPem.AppendSb(sbFullChainPem);

    //  Load the combined PEM into a Chilkat PFX object.
    CkPfx pfx = new CkPfx();
    success = pfx.LoadPem(sbPem.getAsString(),"no password required");
    if (success == false) {
        Log.i(TAG, pfx.lastErrorText());
        return;
        }

    //  Write the PFX w/ a password.
    String pfxPassword = "secret";
    success = pfx.ToFile(pfxPassword,"qa_output/sample.pfx");
    if (success == false) {
        Log.i(TAG, pfx.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."
  }
}