(Swift) Get a Certificate's Key Size

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

Chilkat Downloads for the Swift Programming Language MAC OS X (Cocoa) Objective-C/Swift Libs iOS Objective-C/Swift Libs

func chilkatTest() {
    //  For this example, I have a certificate in raw base64 format (not PEM),
    //  that looks like this:  "MIIGkDCCBHigAwIBAgIUMDA ... s/iqLsLA=="
    let sbCertBase64 = CkoStringBuilder()
    var success: Bool = sbCertBase64.LoadFile("qa_data/certs/base64Cert.txt", charset: "utf-8")

    let cert = CkoCert()
    success = cert.LoadFromBase64(sbCertBase64.GetAsString())
    if success != true {
        print("\(cert.LastErrorText)")
        return
    }

    //  Get the public key.
    var pubKey: CkoPublicKey? = cert.ExportPublicKey()
    if cert.LastMethodSuccess != true {
        print("\(cert.LastErrorText)")
        return
    }

    //  In Chilkat version v9.5.0.67, the KeySize property was added.
    var numBits: Int = pubKey!.KeySize.intValue
    print("Number of bits = \(numBits)")

    //  If using an older version of Chilkat, the key size can be obtained like this:
    let xml = CkoXml()
    xml.LoadXml(pubKey!.GetXml())

    let binDat = CkoBinData()
    binDat.AppendEncoded(xml.GetChildContent("Modulus"), encoding: "base64")

    numBits = 8 * binDat.NumBytes.intValue
    print("Number of bits = \(numBits)")

    pubKey = nil

}