PureBasic

FTP over Implicit TLS (Ssl, AuthSsl, AutoFix)

Demonstrates the SSL/TLS connection-mode properties Ssl, AuthSsl, and AutoFix. Setting Ssl true selects implicit FTPS, in which TLS begins immediately after the TCP connection on port 990.

Background: FTP has two ways to add TLS: implicit (this example) starts encrypted from the first byte on a dedicated port, 990; explicit (via AuthTls) connects in the clear on port 21 and issues AUTH TLS to upgrade. Explicit is the modern standard; implicit persists mainly for legacy servers. AuthSsl is an obsolete AUTH SSL variant to avoid. AutoFix, on by default, infers the mode from the port — disable it when you set these properties explicitly so it does not override your choice.

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IncludeFile "CkFtp2.pb"

Procedure ChilkatExample()

    success.i = 0

    ftp.i = CkFtp2::ckCreate()
    If ftp.i = 0
        Debug "Failed to create object."
        ProcedureReturn
    EndIf

    CkFtp2::setCkHostname(ftp, "ftp.example.com")
    CkFtp2::setCkUsername(ftp, "myFtpLogin")

    ;  Normally you would not hard-code the password in source.  You should instead obtain it
    ;  from an interactive prompt, environment variable, or a secrets vault.
    CkFtp2::setCkPassword(ftp, "myPassword")

    ;  Ssl = 1 selects IMPLICIT FTPS: TLS begins immediately after the TCP connection, before
    ;  the greeting.  Port 990 is conventional for implicit FTPS.  Ssl takes priority over AuthTls
    ;  and AuthSsl.
    CkFtp2::setCkSsl(ftp, 1)
    CkFtp2::setCkPort(ftp, 990)

    ;  AuthSsl selects the legacy AUTH SSL command and is very uncommon -- use AuthTls (explicit
    ;  FTPS) for modern servers instead.  Left 0 here.
    CkFtp2::setCkAuthSsl(ftp, 0)

    ;  AutoFix (default 1) automatically adjusts Ssl/AuthTls/AuthSsl based solely on the Port
    ;  (21 or 990).  Disable it when setting these properties explicitly, as here.
    CkFtp2::setCkAutoFix(ftp, 0)

    success = CkFtp2::ckConnect(ftp)
    If success = 0
        Debug CkFtp2::ckLastErrorText(ftp)
        CkFtp2::ckDispose(ftp)
        ProcedureReturn
    EndIf

    Debug "Connected using implicit FTPS."

    success = CkFtp2::ckDisconnect(ftp)
    If success = 0
        Debug CkFtp2::ckLastErrorText(ftp)
        CkFtp2::ckDispose(ftp)
        ProcedureReturn
    EndIf



    CkFtp2::ckDispose(ftp)


    ProcedureReturn
EndProcedure