Dart

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. Dart

import 'package:chilkat/chilkat.dart';

void main() {
  // 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

  final sbPem = CkStringBuilder();
  try {
    sbPem.loadFile('qa_data/pem/lets_encrypt/privkey.pem', 'utf-8');
  } on ChilkatException {
    print('Failed to load privkey.pem');
    return;
  }

  // To be safe, append a blank line..
  sbPem.appendLine('', false);

  final sbFullChainPem = CkStringBuilder();
  try {
    sbFullChainPem.loadFile('qa_data/pem/lets_encrypt/fullchain.pem', 'utf-8');
  } on ChilkatException {
    print('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.
  final pfx = CkPfx();
  try {
    pfx.loadPem(sbPem.getAsString(), 'no password required');
  } on ChilkatException catch (e) {
    print(e.lastErrorText);
    return;
  }

  // Write the PFX w/ a password.
  final pfxPassword = 'secret';
  try {
    pfx.toFile(pfxPassword, 'qa_output/sample.pfx');
  } on ChilkatException catch (e) {
    print(e.lastErrorText);
    return;
  }

  print('Success!');
}