(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.)

Note: This example requires Chilkat v11.0.0 or greater.

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func chilkatTest() {
    var success: Bool = false

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

    let cert = CkoCert()!
    success = cert.load(fromBase64: sbCertBase64.getAsString())
    if success == false {
        print("\(cert.lastErrorText!)")
        return
    }

    // Get the public key.
    let pubKey = CkoPublicKey()!
    cert.get(pubKey)

    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.load(pubKey.getXml())

    let binDat = CkoBinData()!
    binDat.appendEncoded(xml.getChildContent("Modulus"), encoding: "base64")

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

}