(Node.js) Convert Let's Encrypt PEM Files to a PFX

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

Install Chilkat for Node.js and Electron using npm at Chilkat npm packages for Node.js Chilkat npm packages for Electron on Windows, Linux, MacOSX, and ARM

var os = require('os');
if (os.platform() == 'win32') {  
    if (os.arch() == 'ia32') {
        var chilkat = require('@chilkat/ck-node21-win-ia32');
    } else {
        var chilkat = require('@chilkat/ck-node21-win64'); 
    }
} else if (os.platform() == 'linux') {
    if (os.arch() == 'arm') {
        var chilkat = require('@chilkat/ck-node21-arm');
    } else if (os.arch() == 'x86') {
        var chilkat = require('@chilkat/ck-node21-linux32');
    } else {
        var chilkat = require('@chilkat/ck-node21-linux64');
    }
} else if (os.platform() == 'darwin') {
    if (os.arch() == 'arm64') {
        var chilkat = require('@chilkat/ck-node21-mac-m1');
    } else {
        var chilkat = require('@chilkat/ck-node21-macosx');
    }
}

function chilkatExample() {

    // 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

    var sbPem = new chilkat.StringBuilder();
    var success = sbPem.LoadFile("qa_data/pem/lets_encrypt/privkey.pem","utf-8");
    if (success == false) {
        console.log("Failed to load privkey.pem");
        return;
    }

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

    var sbFullChainPem = new chilkat.StringBuilder();
    success = sbFullChainPem.LoadFile("qa_data/pem/lets_encrypt/fullchain.pem","utf-8");
    if (success == false) {
        console.log("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.
    var pfx = new chilkat.Pfx();
    success = pfx.LoadPem(sbPem.GetAsString(),"no password required");
    if (success == false) {
        console.log(pfx.LastErrorText);
        return;
    }

    // Write the PFX w/ a password.
    var pfxPassword = "secret";
    success = pfx.ToFile(pfxPassword,"qa_output/sample.pfx");
    if (success == false) {
        console.log(pfx.LastErrorText);
        return;
    }

    console.log("Success!");

}

chilkatExample();