(Swift 2) POP3 Verify Signed (S/MIME) Email

Demonstrates how to download and verify digitally signed S/MIME email.

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

func chilkatTest() {
    // This example requires the Chilkat API to have been previously unlocked.
    // See Global Unlock Sample for sample code.

    let mailman = CkoMailMan()
    var success: Bool

    // Set the POP3 server's hostname
    mailman.MailHost = "pop.someMailServer.com"

    // Set the POP3 login/password.
    mailman.PopUsername = "myLogin"
    mailman.PopPassword = "myPassword"

    var sa: CkoStringArray? = mailman.GetUidls()
    if mailman.LastMethodSuccess == false {
        print("\(mailman.LastErrorText)")
        return
    }

    var email: CkoEmail?
    var uidl: String?

    var i: Int = 0
    while i < sa!.Count.intValue {

        uidl = sa!.GetString(i)

        email = mailman.FetchEmail(uidl)
        if mailman.LastMethodSuccess == false {
            print("\(mailman.LastErrorText)")
            sa = nil
            return
        }

        print("\(email!.From)")
        print("\(email!.Subject)")

        // The security layers of signed and/or encrypted emails
        // are automatically "unwrapped" when loaded into
        // a Chilkat email object.
        // An application only needs to check to see if an email
        // was received signed or encrypted, and then examine
        // the success/failure.  For example:
        if email!.ReceivedSigned == true {

            print("This email was signed.")

            // Check to see if the signatures were verified.
            if email!.SignaturesValid == true {
                print("Digital signature(s) verified.")
                print("Signer: \(email!.SignedBy)")

                // The certificate used for signing may be obtained
                // by calling email.GetSignedByCert.
                var cert: CkoCert?
                cert = email!.GetSignedByCert()
                if email!.LastMethodSuccess == false {
                    print("Failed to get signing certificate object.")
                }
                else {
                    print("Signing cert: \(cert!.SubjectCN)")
                    cert = nil
                }

            }
            else {
                print("Digital signature verification failed.")
            }

        }

        email = nil
        i = i + 1
    }

    sa = nil

    mailman.Pop3EndSession()

}