(Swift 3,4,5...) POP3 Read S/MIME Encrypted Email

Read S/MIME encrypted 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 assumes the Chilkat API to have been previously unlocked.
    // See Global Unlock Sample for sample code.

    // The mailman object is used for receiving (POP3) 
    // and sending (SMTP) email.
    let mailman = CkoMailMan()!

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

    // Set the POP3 login/password.
    mailman.popUsername = "myLogin"
    mailman.popPassword = "myPassword"

    // If running on Microsoft Windows, the Chilkat mailman
    // will automatically search the registry-based certificate stores
    // for matching certificates and private keys required for
    // decryption.  However, on Linux, MAX OS X, and other
    // operating systems, no such thing exists.  Therefore, you'll 
    // need to specify one or more PFX (.p12 / .pfx) files as
    // sources for locating the certs required for decyrption.
    var success: Bool = mailman.addPfxSourceFile("/pfxFiles/certs_and_keys_1.pfx", password: "pfxPassword1")
    if success != true {
        print("\(mailman.lastErrorText!)")
        return
    }

    success = mailman.addPfxSourceFile("/pfxFiles/certs_and_keys_2.pfx", password: "pfxPassword2")
    if success != true {
        print("\(mailman.lastErrorText!)")
        return
    }

    // ...
    // Note: On MS Windows, it is not required to provide PFX sources
    // if the needed certs and private keys are already installed
    // on the system (in the registry-based certificate stores).

    // Copy the all email from the user's POP3 mailbox 
    // into a bundle object.  The email remains on the server.
    var bundle: CkoEmailBundle? = mailman.copyMail()
    if mailman.lastMethodSuccess == false {
        print("\(mailman.lastErrorText!)")
        return
    }

    // S/MIME security envelopes are automatically "unwrapped" 
    // when a message is retrieved from the server. Signed emails are automatically verified, and 
    // encrypted emails are automatically decrypted, restoring the email to the original state before 
    // signing and/or encrypting. Information about the signing and encrypting certificates can be 
    // retrieved from the Email object (methods: GetSignedByCert, GetEncryptedByCert; 
    // properties: SignedBy, EncryptedBy, SignaturesValid, Decrypted, ReceivedSigned, 
    // ReceivedEncrypted).

    // Loop over the bundle, 
    var i: Int = 0
    while i < bundle!.messageCount.intValue {
        var email: CkoEmail?
        email = bundle!.getEmail(i)

        print("\(email!.from!)")
        print("\(email!.subject!)")

        // At this point, if the email was signed and/or encrypted, it is already "unwrapped", i.e.
        // the email is already decrypted and in a state as if it were never signed or encrypted.
        // You may check to see if the email was received encrypted or signed, and if so,
        // whether it was successfully unwrapped and who signed or encrypted it:
        if email!.receivedEncrypted == true {

            print("This email was encrypted when received.")
            if email!.decrypted == true {
                print("This email was successfully decrypted.  It was encrypted by:")
                print("\(email!.encryptedBy!)")
            }
            else {
                print("This email was not decrypted.")
            }

        }

        if email!.receivedSigned == true {

            print("This email was signed when received.")
            if email!.signaturesValid == true {
                print("The signature was verified.  It was signed by:")
                print("\(email!.signedBy!)")
            }
            else {
                print("The signature verification failed.")
            }

        }

        // The email's body, HTML body, attachments, etc.
        // are decrypted and available just like any non-encrypted email.

        print("--")
        email = nil

        i = i + 1
    }

    bundle = nil

}