NAV 2013 - .Net Integration SSL/TLS Error

remco_rausch

Hi,

We integrate with Hermes Courier Services from NAV using a home written C# project that communicates with a Hermes SOAP Web Service. It is called on warehouse shipment release.

This runs on 3 NAV services:
Service 1: Client Service - Windows Credential Type
Service 2: Client Service - NavUserPassword
Service 3: NAS Service - Windows Credential Type

All service run on the same machine and all have the same service account setup against them.

This solution has been working fine for around 2 months but stopped working last Tuesday. We restarted all the NAV Services and rebooted the machine. The result being:
Service 1: Works fine for a period but will then stop working
Service 2: Has been fine since, no reported problems
Service 3: Works for around 5 shipments and then falls over

The error message that it is falling over on for all services is as follows:

Event Viewer:
"A fatal alert was received from the remote endpoint. The TLS protocol defined fatal alert code is 40."

Message from Hermes Web Service Class (i.e. code running on our side of things):
'Error in Communication: Could not establish secure channel for SSL/TLS with authority 'www.hermes-europe.co.uk'.'


The checks we have done so far:
1. Install the NAS on a separate server, result is the same
2. Check over all the code for modifications, nothing has been modified for the last month. Either NAV code or the C#
3. Check the Server for Windows Updates, none installed since September (I know.....)
4. Checked with Hermes to see if they had any other customers with problems but they have had not.

It is not a data issue as when a shipment falls over on the NAS it can be immediately released manually using the standard client.

My question is as follows, the SSL/TLS error we receive has normally got to do with certificates, we have checked these and they seem to be fine, also not changed for about a month. What is the difference between how the different service run, is there some sort of caching that could take place against services and certificates? It just seems very weird that one service falls over nearly straightaway, another falls over randomly and the third has been stable the whole time.

Does anyone have any ideas as I am ](*,) .

Thanks!

Remco

oki

It seems that it has nothing to do with Nav but with Windows Security Updates
A possible solution may be here
http://www.zdnet.com/article/microsoft-warns-of-problems-with-schannel-security-update/
hope this helps

There are several articles about this phenomenon on the internet. Simply search for "The TLS protocol defined fatal alert code is 40"

Oki

remco_rausch

Thanks Oki.

I had already googled the message and come across this article, that update came out in November and we have not installed updates since September.

remco_rausch

Just an update, we have installed all possible updates and the problem is still the same, any help would be appreciated.