Lua

Upgrade an FTP Control Channel to TLS (ConvertToTls)

Demonstrates the Chilkat Ftp2.ConvertToTls method, which upgrades an already-connected clear FTP control channel to explicit TLS. It takes no arguments and is used with a manually staged connection created by ConnectOnly while Ssl is disabled.

Background: This exposes the explicit-FTPS AUTH TLS upgrade as a discrete step for the rare case where you need to do something on the clear connection first — inspect the greeting, apply a workaround — before securing it. In the normal case you simply set AuthTls and let Connect perform the upgrade automatically; this manual path exists for staged control.

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Lua

local chilkat = require("chilkat")

-- Demonstrates the Ftp2.ConvertToTls method, which upgrades an already-connected clear FTP control
-- channel to explicit TLS.  It takes no arguments.  It is used with a manually staged connection
-- created by ConnectOnly while Ssl is disabled.

local ftp = chilkat.Ftp2.new()

ftp.hostname = "ftp.example.com"
ftp.port = 21

-- Connect in clear text first (Ssl is false).
local success = ftp:connect_only()
if not success then
    print(ftp.last_error_text)
    return
end

-- Upgrade the control channel to explicit TLS (AUTH TLS).
success = ftp:convert_to_tls()
if not success then
    print(ftp.last_error_text)
    return
end

-- Now authenticate over the encrypted control channel.
ftp.username = "myFtpLogin"
ftp.password = "myPassword"
success = ftp:login_after_connect_only()
if not success then
    print(ftp.last_error_text)
    return
end

print("Control channel upgraded to TLS and logged in.")

success = ftp:disconnect()
if not success then
    print(ftp.last_error_text)
    return
end