(Node.js) Verify an RSA Signature Against the Signed Hash

See more Apple Keychain Examples

Demonstrates how to validate an RSA Signature against the hash that was signed.

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() {

    var bd = new chilkat.BinData();
    var i;
    for (i = 0; i <= 100; i++) {
        bd.AppendEncoded("000102030405060708090A0B0C0D0E0F","hex");
    }

    var sha256_base64 = bd.GetHash("sha256","base64");
    console.log("sha256 hash in base64 format: " + sha256_base64);

    var base64_rsa_sig = "AwF2BbOvL6jA5DwmMAc9n6J2Cc8PI6Rj5W079+aKJcIEtPWRzHor0Bvc3aftGM3Jbgj6SXlIC3M3RYS7UZOnfiHKFNZgbxaNT5WwsWooK42ZkC8DBZl0p7OunBUKd5SciUo+TKilioeUkriN3L1Zl9hwi3HVDVqgVo3XXskwIftSqLSFlepTLTmOWj9Y93dp8J4D9RyLtNgFQBc0WB22tyJTsuY56mLcWe1AMF3LizB9OrbwjynF2u16xWlrJdugccz795fJBUV9aQSD+8S3KeqwQhoi8RK1uhD68aGCyaSpBq0NZ8COAkn7MXaF4POxrAAt8udfHM+PRfSOptcH/w==";

    // Get the public key to be used for signature verification.
    var pubKey = new chilkat.PublicKey();
    var 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 against the signature.
    rsa.EncodingMode = "base64";
    success = rsa.VerifyHashENC(sha256_base64,"sha256",base64_rsa_sig);

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


}

chilkatExample();