FTP over Implicit TLS (Ssl, AuthSsl, AutoFix)

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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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#include <C_CkFtp2.h>

void ChilkatSample(void)
    {
    BOOL success;
    HCkFtp2 ftp;

    success = FALSE;

    ftp = CkFtp2_Create();

    CkFtp2_putHostname(ftp,"ftp.example.com");
    CkFtp2_putUsername(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_putPassword(ftp,"myPassword");

    //  Ssl = TRUE 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_putSsl(ftp,TRUE);
    CkFtp2_putPort(ftp,990);

    //  AuthSsl selects the legacy AUTH SSL command and is very uncommon -- use AuthTls (explicit
    //  FTPS) for modern servers instead.  Left FALSE here.
    CkFtp2_putAuthSsl(ftp,FALSE);

    //  AutoFix (default TRUE) automatically adjusts Ssl/AuthTls/AuthSsl based solely on the Port
    //  (21 or 990).  Disable it when setting these properties explicitly, as here.
    CkFtp2_putAutoFix(ftp,FALSE);

    success = CkFtp2_Connect(ftp);
    if (success == FALSE) {
        printf("%s\n",CkFtp2_lastErrorText(ftp));
        CkFtp2_Dispose(ftp);
        return;
    }

    printf("Connected using implicit FTPS.\n");

    success = CkFtp2_Disconnect(ftp);
    if (success == FALSE) {
        printf("%s\n",CkFtp2_lastErrorText(ftp));
        CkFtp2_Dispose(ftp);
        return;
    }



    CkFtp2_Dispose(ftp);

    }