EF Core SqlServer connect hang

Describe the bug

Can not able to connect SQL Server instance. No exceptions, it just hangs at ‘OpenConnection’ function indefinitely. Even though I give 10 seconds of timeout, it does not timeout.

No exceptions. Just logs. Trace enabled.

May 13 09:08:46 ubuntu pompa-proxy[4071]: dbug: Microsoft.EntityFrameworkCore.Infrastructure[10401]
May 13 09:08:46 ubuntu pompa-proxy[4071]:       An 'IServiceProvider' was created for internal use by Entity Framework.
May 13 09:08:52 ubuntu pompa-proxy[4071]: info: Microsoft.EntityFrameworkCore.Infrastructure[10403]
May 13 09:08:52 ubuntu pompa-proxy[4071]:       Entity Framework Core 3.1.4 initialized 'OrkaContext' using provider 'Microsoft.EntityFrameworkCore.SqlServer' with options: CommandTimeout=10
May 13 09:08:52 ubuntu pompa-proxy[4071]: dbug: Microsoft.EntityFrameworkCore.Database.Connection[20000]
May 13 09:08:52 ubuntu pompa-proxy[4071]:       Opening connection to database 'ORKA_0996_2020' on server '192.168.0.250\ORKASQL'.

To reproduce

                var context = _serviceLocator.GetInstance<OrkaContext>();
                
                context.Database.OpenConnection();

                _logger.LogInformation("Execution is starting...");

                context.Database.ExecuteSqlRaw(@"...

Expected behavior

A connection should be opened or an exception should be thrown.

Further technical details

Microsoft.Data.SqlClient version: 3.1.4 .NET target: .NET Core 3.1.4 SQL Server version: SQL Server 2012 SP4 Operating system: Ubuntu 20.04 (Client) , Windows Server 2012 (Server)

Additional context It was working until I have upgraded my ubuntu. At first, I got an SSL exception. I have upgraded the SQL server to SP4 to resolve issue, it did solve problem. but hang problem started.

I can connect to the database from the server’s itself by sql server management studio using sql server authentication. There are windows computers in the office, I can confirm they can connect to the sql server, too.

[oguzhantopcu]

I have resolved my issue by setting MinProtocol = TLSv1.1 at openssl.cnf. BTW MinProtocol = TLSv1.0 did not work, that was the main reason I have struggled with this issue for hours.

But I think infinite hang should be solved. It is up to you.

[cheenamalhotra]

Could you also check if server certificate is not encrypted with SHA1? Related issue was also reported here: https://github.com/dotnet/SqlClient/issues/538#issuecomment-622587024