JavaScript

Get a Certificate's Key Size

Demonstrates how to get the RSA key size of a certificate (for example, 1024-bit, 2048-bit, etc.)

Note

This example is intended for running within a Chilkat.Js embedded JavaScript engine. All Chilkat JavaScript examples require Chilkat v11.4.0 or greater.

JavaScript

var success = false;

// For this example, I have a certificate in raw base64 format (not PEM),
// that looks like this:  "MIIGkDCCBHigAwIBAgIUMDA ... s/iqLsLA=="
var sbCertBase64 = new CkStringBuilder();
success = sbCertBase64.LoadFile("qa_data/certs/base64Cert.txt","utf-8");

var cert = new CkCert();
success = cert.LoadFromBase64(sbCertBase64.GetAsString());
if (success == false) {
    console.log(cert.LastErrorText);
    return;
}

// Get the public key.
var pubKey = new CkPublicKey();
cert.GetPublicKey(pubKey);

var numBits = pubKey.KeySize;
console.log("Number of bits = " + numBits);

// If using an older version of Chilkat, the key size can be obtained like this:
var xml = new CkXml();
xml.LoadXml(pubKey.GetXml());

var binDat = new CkBinData();
binDat.AppendEncoded(xml.GetChildContent("Modulus"),"base64");

numBits = 8 * binDat.NumBytes;
console.log("Number of bits = " + numBits);