NT 4 to NT 7 failure

[cwtart]

Hello,

My app in the field, when started, posts some xml via a Nettalk web client to a NetTalk web server running in my office. This is used as a registration validation. The server side checks some stuff and sends back an xml packet.
 
The problem is now that I have upgraded the Nettalk web server in my office end to NT 7 none of the apps in the field that are still compiled with NT 4 can communicate with the server. The apps in the field that are compiled in NT 7 have no problems. This is using https posts to the server.
 
I cannot figure this out – none of the code or procedures in the field app have changed other than going from NT 4 to NT 7. What would a NT 7 web client post to the server that would be any different than a NT 4 web client – its just an HTTPS post right? Should be exactly the same if the code that generates the POST is the same?

Chuck

[Bruce]

Hi Chuck,

NT4 to NT7 is a huge leap, so there are quite a few things that might be in play here.

The first thing to do is narrow down the scope of the problem. ie

a) do the clients _connect_ to the server ok? There were some changes to SSL along the way - especially the fact that some of the weaker SSL ciphers are turned off by default, but I don't _think_ that would cause this problem. Do they get any error at the client side which may give clues?

b) Do you see the post appear in the Web Server window log?
If the post arrives in the log, then the connection (ie SSL) is ok. So then we follow it through the log to...

c) Does it arrive in your WebServer procedure?

With regard to POST's - there have been some changes along the way - most notably the way content length is handled, and also the default protocol (HTTP 1.0 / HTTP 1.1). I can't _think_ of anything off-hand which would cause a problem, but obviously you've jumped a couple hundred builds here so clearly somthing has changed.

cheers
Bruce

[cwtart]

Bruce,

The POSTs are not even being showed in the web server log - so I suspect SSL may be the underlying cause.

When the web server was NT 4 it received POSTs from both NT 4 and NT 7 clients but now that the web server is NT 7 it only receives POSTs from NT 7 clients.

Chuck

[cwtart]

Bruce,

On the client side the connection is just timing out - error -57

Chuck

[Larry Sand]

Chuck,

Check the serverObject.SSLMethod property and what you're setting the clients to,  IIRC NT5.30+ defaults to NET:SSLMethodSSLv3 and NT4 was NET:SSLMethodSSLv23 and the connection fails.

Larry Sand

[Bruce]

Hi Chuck,

See this thread;
http://www.nettalkcentral.com/index.php?option=com_smf&Itemid=36&topic=1023.0

This shows you how to turn your Nt7 server back so it supports the weaker SSL Ciphers and Levels.

cheers
Bruce

[cwtart]

Bruce,

Thanks - that worked fine - I set SSL back to NET:SSLMethodSSLv23  and it works now.

Chuck