(Swift 3,4,5...) Using WS_FTP Self-signed Certificate file (.crt) and Private Key File. (.key)

Demonstrates how to use a self-signed certificate created by WS_FTP with Chilkat FTP2.

Note: It is usually not necessary for the FTP client to use a client-side certificate. Most FTP servers using SSL and TLS connections (explicit or implicit) do not require client-side certs. In addition, some high-security FTP servers require "real" certificates -- meaning certificates issued by a real certificate authority with a chain of authentication that leads to a trusted root certificate. The certificates created by WS_FTP are self-signed and untrusted.

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.

    // Important:  Before running this program, convert your
    // .crt and .key files to a .p12 using OpenSSL:
    // The command is this:
    // openssl pkcs12 -export -in test.crt -inkey test.key -out test.p12
    // 

    let ftp = CkoFtp2()!

    ftp.hostname = "ftp.***.com"
    ftp.port = 21
    ftp.username = "testLogin"
    ftp.password = "testPassword"

    // This example will use explict TLS/SSL.
    // Establish an explicit secure channel after connection
    // on the standard FTP port 21.
    ftp.authTls = true

    // The Ssl property is for establishing an implicit SSL connection
    // on port 990.  Because this example uses explicit SSL, it 
    // should remain false.
    ftp.ssl = false

    // Create an instance of a certificate store object, load a .p12 file,
    // locate the certificate we need, and use it for signing.
    // (a P12/PFX file may contain more than one certificate.)
    let certStore = CkoCertStore()!
    // The 1st argument is the filename, the 2nd arg is the 
    // .p12 file's password.  (OpenSSL will prompty you to set a password
    // when converting the .crt and .key into a .p12).
    var success: Bool = certStore.loadPfxFile("test.p12", password: "secret")
    if success != true {
        print("\(certStore.lastErrorText!)")
        return
    }

    var cert: CkoCert? = certStore.findCert(bySubjectCN: "Your cert's common name")
    if certStore.lastMethodSuccess == false {
        print("\(certStore.lastErrorText!)")
        return
    }

    success = ftp.setSslClientCert(cert)

    cert = nil

    // Connect and login to the FTP server.
    success = ftp.connect()
    if success != true {
        print("\(ftp.lastErrorText!)")
        return
    }
    else {
        // LastErrorText contains information even when
        // successful. This allows you to visually verify
        // that the secure connection actually occurred.
        print("\(ftp.lastErrorText!)")
    }

    print("Secure FTP Channel Established!")
    print("\(ftp.lastErrorText!)")

    // Do whatever you're doing to do ...
    // upload files, download files, etc...

    // ...
    // ...

    success = ftp.disconnect()

}