how to use standard ftp via ssh tunnel from HPUX to windows

[Grace Li]

I need to ftp files from UNIX server to a windows ftp server (at vender's side). The firewall in my network is opened to allow outbound traffic.

Because the destination server does NOT support sftp, how can I use ssh tunnel to establish the connection?

[Matti_Kurkela]

Both SSH and SFTP require a SSH server program at the destination machine. If the windows server does not support SFTP, it very likely does not support SSH either, so you cannot form a SSH tunnel.

If outbound traffic is allowed, you might be able to use FTP's passive mode. Simply use the command "PASSIVE" before using the PUT command of the FTP client.

In the default "active" mode FTP, the client opens a control connection and authenticates, then the _server_ opens any data transfer connections when needed. As you have discovered, this causes headaches when you must go through a firewall. When using the "passive" mode, the client creates the data connections too.

Remenber that both your passwords AND your data are travelling through the network unencrypted whenever you're using plain FTP.

MK

[Grace Li]

Thank you very much for the reply. in fact the data content is sensitive, that's why it needs to be encripted.
On the windows server, they support implicit / explicite SSL via port 990. What does that means?
I heard about the "lftp" but I have compilation problem when download the package and intall on HPUX.

[Matti_Kurkela]

Apparently the destination server is not just a basic FTP server: it has FTPS functionality available too. FTPS is FTP over SSL, kind of like HTTPS is HTTP over SSL.

Note that SFTP and FTPS are two entirely different things.

For a quick explanation on FTPS, look here:
http://en.wikipedia.org/wiki/FTPS

Here's the FTPS specification:
ftp://ftp.rfc-editor.org/in-notes/rfc4217.txt

You'll need a FTP client program that will support FTPS. "lftp" would be appropriate if you could get it to compile.

As an alternative, you might try a modern version of Kermit. Forget what you may remember of Kermit as a file transfer protocol for modem lines from long ago: a modern Kermit client can handle FTP, FTPS, HTTP, HTTPS, telnet and SSH, and offers an uniform scripting interface for all these protocols.

http://www.columbia.edu/kermit/
http://www.columbia.edu/kermit/ck80.html

By the way, apparently you are not the only one having difficulties compiling lftp:
http://forums.itrc.hp.com/service/forums/questionanswer.do?threadId=1160229

MK

[Grace Li]

I will try Kermit. Thank you.

[Grace Li]

Looks like "Kermit" is available under HP UX 11.23. Does it encrypt data while send out?

[Matti_Kurkela]

Hmm, apparently the Kermit version included with HP-UX 11.23 does not include SSL features. This is probably so that the base OS can be exported to countries that restrict or prohibit the use of encryption by ordinary citizens.

You may have to compile a version of Kermit with SSL support included.

MK

[Grace Li]

Thank Matti. as our project is running out of time, we use a windows server instead. we installed cuteftp software to play the roll as client.