Sample code for 30+ languages & platforms
Unicode C

FTP over Implicit TLS (Ssl, AuthSsl, AutoFix)

See more FTP Examples

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.

Chilkat Unicode C Downloads

Unicode C
#include <C_CkFtp2W.h>

void ChilkatSample(void)
    {
    BOOL success;
    HCkFtp2W ftp;

    success = FALSE;

    ftp = CkFtp2W_Create();

    CkFtp2W_putHostname(ftp,L"ftp.example.com");
    CkFtp2W_putUsername(ftp,L"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.
    CkFtp2W_putPassword(ftp,L"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.
    CkFtp2W_putSsl(ftp,TRUE);
    CkFtp2W_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.
    CkFtp2W_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.
    CkFtp2W_putAutoFix(ftp,FALSE);

    success = CkFtp2W_Connect(ftp);
    if (success == FALSE) {
        wprintf(L"%s\n",CkFtp2W_lastErrorText(ftp));
        CkFtp2W_Dispose(ftp);
        return;
    }

    wprintf(L"Connected using implicit FTPS.\n");

    success = CkFtp2W_Disconnect(ftp);
    if (success == FALSE) {
        wprintf(L"%s\n",CkFtp2W_lastErrorText(ftp));
        CkFtp2W_Dispose(ftp);
        return;
    }



    CkFtp2W_Dispose(ftp);

    }