(Node.js) Duplicate openssl dgst -sha256 -sign private.pem -out sha256.sig in.dat

Demonstrates how to duplicate this OpenSSL command:

openssl dgst -sha256 -sign private.pem -out sha256.sig in.dat

1. Creates a SHA256 digest of the contents of the input file
2. Signs the SHA256 digest using the private key.

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 requires the Chilkat API to have been previously unlocked.
    // See Global Unlock Sample for sample code.

    var pkey = new chilkat.PrivateKey();

    // Load the private key from an PEM file:
    var success = pkey.LoadPemFile("private.pem");
    if (success !== true) {
        console.log(pkey.LastErrorText);
        return;
    }

    var rsa = new chilkat.Rsa();

    // Import the private key into the RSA component:
    success = rsa.ImportPrivateKeyObj(pkey);
    if (success !== true) {
        console.log(rsa.LastErrorText);
        return;
    }

    // OpenSSL uses big-endian.
    rsa.LittleEndian = false;

    // Load the file to be signed.
    var bdFileData = new chilkat.BinData();
    success = bdFileData.LoadFile("in.dat");

    var bdSig = new chilkat.BinData();
    success = rsa.SignBd(bdFileData,"sha256",bdSig);
    if (success !== true) {
        console.log(rsa.LastErrorText);
        return;
    }

    // Save the binary signature to a file.
    success = bdSig.WriteFile("signature.sig");
    if (success !== true) {
        console.log("Failed to write signature.sig.");
        return;
    }

    console.log("Success.");

}

chilkatExample();