user3442435 user3442435 - 1 day ago 7
SQL Question

Sqlconnection still requires ssl but "encrypt=false"

I've an application written in C# (framework 4.6) that uses

System.Data.SqlClient
to communicate with a SQL Server 2014. This application does NOT use SSL to connect to SQL.

The connection to SQL Server fails with this error:


a connection was established but ... protocol error ... opening
session (SSL provider error 0)


On the server, I observe in the events: Schannel errors 36874 and 36888 (A TLS1.2 connection request was received from a remote client application, but none of the cipher suites supported by the client application are supported by the server. )

I've tried to force
encrypt=false
in the connect string to disable any SSL option, but this does not solve the problem.

This error does not occur on all computers of the same network.

Thanks in advance for your help.

Kind regards,

Guy

Answer

We have find a solution for this problem. We need to add news keys on the registry.

[HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\SecurityProviders\SCHANNEL\Protocols\TLS 1.2]
[HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\SecurityProviders\SCHANNEL\Protocols\TLS 1.2\Client]
"DisabledByDefault"=dword:00000001
"Enabled"=dword:00000000

After restart of computer, problem is solved but we dont understand why somes computer would connect with tls 1.2

Comments