C# FTP Client Access Through ISA Server

[Phil Ruelle]

Hi,

I've got an FTP client written in C# which works fine when directly
accessing the internet.

However I need to update it so that it can FTP through an ISA proxy
server. I have downloaded a number of samples but can't get any of
them to work with the proxy.

There appears to be two approaches:

1) Tunnel FTP through HTTP
http://groups.google.com/groups?hl=...oxy+c%23+connect+http&ie=UTF-8&oe=UTF-8&hl=en
I've tried this and the problem I have is that the ISA server is set
to 'integrated authentication' so I get a 407 error response.
Is there a simple way to generate the proxy-authentication header for
NTLM? The client is written in C# so I have access to the .Net classes
but there doesn't seem to be anything suitable - I've looked at
NetworkCredentials but have no idea how this would translate to a HTTP
header.

2) Extend WebRequest/WebResponse
I've had a look through the code for the Microsoft sample (KB 166691)
and it seems to be plain wrong. For example:
a) in OpenControlConnection it tries to get a response after the
socket connection - this hangs indefinitely
b)in GetResponse if a proxy username is defined it processes it into
(e-mail address removed)
c) it connects a socket to the proxy server and then tries to send FTP
commands straight to this socket - do they not have to be wrapped up
to prevent the proxy server from trying to parse/execute them?
I'd be grateful if anyone could explain what's going on here - have I
misunderstood how it works? Has anyone used this architecture as the
basis for a working FTP client via a proxy server (which requires
authentication)?

Finally is there an alternative solution (apart from reconfiguring the
ISA security)?

Thanks in advance,
Phil

 

[Sherif ElMetainy]

Hello

Does your FTP client support PASV mode? If it does try it.

Best regards,
Sherif

 

[Phil Ruelle]

I've only ever used passive mode, in fact it doesn't even support active.

 

[Louis Solomon [SteelBytes]]

I think if you use the WinInet funcs to do the HTTP/1.1 CONNECT, then that
might handle the different auth method.

 

[Chad Z. Hower aka Kudzu]

(e-mail address removed) (Phil Ruelle) wrote in

I've only ever used passive mode, in fact it doesn't even support
active.

What kind of component does not support Active?

 

[Chad Z. Hower aka Kudzu]

(e-mail address removed) (Phil Ruelle) wrote in

this and the problem I have is that the ISA server is set to 'integrated
authentication' so I get a 407 error response. Is there a simple way to
generate the proxy-authentication header for NTLM? The client is written

Yes, but NTLM is not trivial. Indy has FTP and NTLM support
(www.indyproject.org) but I dont remember if the NTLM parts were ported to
..net yet or not.

c) it connects a socket to the proxy server and then tries to send FTP
commands straight to this socket - do they not have to be wrapped up
to prevent the proxy server from trying to parse/execute them?

This is HTTP proxy open port. But you will still need to auth against ISA for
it to let you out.