Tcl

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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Tcl


load ./chilkat.dll

set success 0

#  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.

set ftp [new_CkFtp2]

CkFtp2_put_Hostname $ftp "ftp.example.com"
CkFtp2_put_Port $ftp 21

#  Connect in clear text first (Ssl is false).
set success [CkFtp2_ConnectOnly $ftp]
if {$success == 0} then {
    puts [CkFtp2_lastErrorText $ftp]
    delete_CkFtp2 $ftp
    exit
}

#  Upgrade the control channel to explicit TLS (AUTH TLS).
set success [CkFtp2_ConvertToTls $ftp]
if {$success == 0} then {
    puts [CkFtp2_lastErrorText $ftp]
    delete_CkFtp2 $ftp
    exit
}

#  Now authenticate over the encrypted control channel.
CkFtp2_put_Username $ftp "myFtpLogin"
CkFtp2_put_Password $ftp "myPassword"
set success [CkFtp2_LoginAfterConnectOnly $ftp]
if {$success == 0} then {
    puts [CkFtp2_lastErrorText $ftp]
    delete_CkFtp2 $ftp
    exit
}

puts "Control channel upgraded to TLS and logged in."

set success [CkFtp2_Disconnect $ftp]
if {$success == 0} then {
    puts [CkFtp2_lastErrorText $ftp]
    delete_CkFtp2 $ftp
    exit
}


delete_CkFtp2 $ftp