Disabled SSL on SQL Server, now connection fails

Question

I have a customer that is worried about the latest SSL vulnerability POODLE. They have a utility ( IIS Crypto 1.4 ) that disables SSL 2.0-3.0 on the servers they run it on. They have disabled SSL on both the server my service is running and the remote SQL Server. The SQL connection string is pretty standard:

Server=myServerIPAddress;Database=myDataBase;User Id=myUsername;Password=myPassword;

When my service starts it tries to perform a Linq to SQL query and gets the error:

A connection was successfully established with the server, but then an error occurred during the pre-login handshake. (provider: TCP Provider, error: 0 - An existing connection was forcibly closed by the remote host.)

If they re-enable SSL on the SQL Server it works fine. My program is a Windows Service built on .NET 3.5. What is the cause of this error, and where can I make adjustments so my service will run?

Answer 1

See if your windows service code has any line like this in it:

ServicePointManager.SecurityProtocol = SecurityProtocolType.Ssl3;

That would limit the protocol to ssl3 which has now been disabled, which leads to this type of error.