(Node.js) RSA Sign Binary Data and Verify (Recover the Original Data)

Demonstrates how to RSA sign binary data and then verify/recover the original data.

Note: This example uses methods introduced in Chilkat v9.5.0.77.

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.

    // Load an RSA private key for signing.
    var privKey = new chilkat.PrivateKey();
    var success = privKey.LoadEncryptedPemFile("qa_data/pem/rsa_passwd.pem","passwd");
    if (success !== true) {
        console.log(privKey.LastErrorText);
        return;
    }

    var rsa = new chilkat.Rsa();
    rsa.ImportPrivateKeyObj(privKey);

    // We have some binary data (in hex) to sign
    var originalData = "0102030405060708090A";
    var bd = new chilkat.BinData();
    bd.AppendEncoded(originalData,"hex");

    // If successful, the contents of bd are replaced with the RSA signature.
    success = rsa.OpenSslSignBd(bd);
    if (success !== true) {
        console.log(rsa.LastErrorText);
        return;
    }

    // Show the RSA signature in base64
    console.log(bd.GetEncoded("base64"));

    // ------------------------------------------
    // Get the public key from the private key
    // pubKey: PublicKey
    var pubKey = privKey.GetPublicKey();

    // Verify the signature and extract the original data.
    var rsa2 = new chilkat.Rsa();
    rsa2.ImportPublicKeyObj(pubKey);

    var bVerified = rsa2.OpenSslVerifyBd(bd);
    console.log("signature verified: " + bVerified);

    // Show the original data:
    console.log("original data: " + bd.GetEncoded("hex"));


}

chilkatExample();