(Node.js) Verfies an RSA Signature

See more Apple Keychain Examples

Verifies an RSA signature against the original data.

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

var os = require('os');
if (os.platform() == 'win32') {  
  var chilkat = require('@chilkat/ck-node23-win64'); 
} else if (os.platform() == 'linux') {
    if (os.arch() == 'arm') {
        var chilkat = require('@chilkat/ck-node23-linux-arm');
    } else if (os.arch() == 'arm64') {
        var chilkat = require('@chilkat/ck-node23-linux-arm64');
    } else {
        var chilkat = require('@chilkat/ck-node23-linux-x64');
    }
} else if (os.platform() == 'darwin') {
  var chilkat = require('@chilkat/ck-node23-mac-universal');
}

function chilkatExample() {

    // The following data was signed by the following example:
    // RSA Sign using a Private Key on a USB Token or Smartcard
    var bd = new chilkat.BinData();
    var i;
    for (i = 0; i <= 100; i++) {
        bd.AppendEncoded("000102030405060708090A0B0C0D0E0F","hex");
    }

    // Load the signature
    var bdSig = new chilkat.BinData();
    var success = bdSig.LoadFile("rsaSignatures/test1.sig");
    if (success == false) {
        console.log("Failed to load the RSA signature");
        return;
    }

    // Get the public key to be used for signature verification.
    var pubKey = new chilkat.PublicKey();
    success = pubKey.LoadFromFile("rsaKeys/chilkat-rsa-2048.pem");
    if (success == false) {
        console.log(pubKey.LastErrorText);
        return;
    }

    var rsa = new chilkat.Rsa();
    rsa.ImportPublicKeyObj(pubKey);

    // Verify the hash of the data against the signature.
    // We pass in the original data.  Internally, the hash is generated
    // and used to validate the signature.
    // Validating the RSA signature means two things:  
    // (1) the original data is exactly what was signed, and 
    // (2) it was signed by the owner of the RSA private key.
    success = rsa.VerifyBd(bd,"sha256",bdSig);

    if (success == false) {
        console.log(rsa.LastErrorText);
        console.log("Signature invalid.");
    }
    else {
        console.log("Signature valid.");
    }


}

chilkatExample();