(Node.js) RSA Hash Binary Data and Sign (and Verify)

Demonstrates how to sign the hash of binary data. Also demonstrates how to verify the RSA signature.

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 bdData = new chilkat.BinData();
    bdData.AppendEncoded(originalData,"hex");

    // Hash (SHA-256) and sign the hash:
    var bdSignature = new chilkat.BinData();
    success = rsa.SignBd(bdData,"sha256",bdSignature);
    if (success !== true) {
        console.log(rsa.LastErrorText);
        return;
    }

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

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

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

    var bVerified = rsa2.VerifyBd(bdData,"sha256",bdSignature);
    console.log("signature verified: " + bVerified);


}

chilkatExample();