Swift

Get the S/MIME Signer's Certificate

Demonstrates the Chilkat Mime.LastSignerCert method, which loads the signer certificate at a zero-based index from the most recent successful verification (or security-unwrapping) into a Cert. The first argument is the signer index and the second is the receiving Cert.

Note: The file paths are relative to the application's current working directory. Absolute paths may also be used. Supply the paths appropriate to your own environment.

Background: Verifying tells you the signature is mathematically valid, but you usually also need to know who signed — the subject, the issuer, the validity dates — to decide whether to trust it. This retrieves each signer's certificate after verification so your code can inspect and apply its own trust rules. A message can have multiple signers, so iterate from 0 to NumSignerCerts - 1.

Chilkat Swift Downloads

Download Chilkat for Swift

Swift


func chilkatTest() {
    var success: Bool = false

    let mime = CkoMime()!
    success = mime.loadFile(path: "qa_data/signed.eml")
    if success == false {
        print("\(mime.lastErrorText!)")
        return
    }

    //  After a successful verification, load each signer's certificate to inspect it.  The 1st argument
    //  is the zero-based signer index and the 2nd is a Cert object that receives the certificate.
    success = mime.verify()
    if success != true {
        print("\(mime.lastErrorText!)")
        return
    }

    var n: Int = mime.numSignerCerts.intValue
    let cert = CkoCert()!
    var i: Int
    for i = 0; i <= n - 1; i++ {
        success = mime.lastSignerCert(index: i, cert: cert)
        if success == false {
            print("\(mime.lastErrorText!)")
            return
        }

        print("Signer \(i): \(cert.subjectCN!) (issued by \(cert.issuerCN!))")
    }


}