Not able to connect to a SQL Server db from .Net core app on RHEL 7

Question

I have made a .NET Core 2.2 application from Visual Studio 2017 on my Windows machine and tried to host it on a Linux machine running RHEL 7 Server. I am trying to connect to a SQL Server DB with SqlPassword authentication (I am having a user id and password) using ADO.NET from the application.

I am constantly getting an exception when I am doing this. The issue that I have observed here:

Message: Cannot authenticate using Kerberos. Ensure Kerberos has been initialized on the client with 'kinit' and a Service Principal Name has been registered for the SQL Server to allow Kerberos authentication. ErrorCode=InternalError, Exception=Interop+NetSecurityNative+GssApiException: GSSAPI operation failed with error - An invalid status code was supplied (SPNEGO cannot find mechanisms to negotiate). at System.Net.Security.NegotiateStreamPal.GssInitSecurityContext(SafeGssContextHandle& context, SafeGssCredHandle credential, Boolean isNtlm, SafeGssNameHandle targetName, GssFlags inFlags, Byte[] buffer, Byte[]& outputBuffer, UInt32& outFlags, Int32& isNtlmUsed) at System.Net.Security.NegotiateStreamPal.EstablishSecurityContext(SafeFreeNegoCredentials credential, SafeDeleteContext& context, String targetName, ContextFlagsPal inFlags, SecurityBuffer inputBuffer, SecurityBuffer outputBuffer, ContextFlagsPal& outFlags) at System.Data.SqlClient.SNI.SNIProxy.GenSspiClientContext(SspiClientContextStatus sspiClientContextStatus, Byte[] receivedBuff, Byte[]& sendBuff, Byte[] serverName) at System.Data.SqlClient.SNI.TdsParserStateObjectManaged.GenerateSspiClientContext(Byte[] receivedBuff, UInt32 receivedLength, Byte[]& sendBuff, UInt32& sendLength, Byte[] _sniSpnBuffer) at System.Data.SqlClient.TdsParser.SNISSPIData(Byte[] receivedBuff, UInt32 receivedLength, Byte[]& sendBuff, UInt32& sendLength), StackTrace: at System.Data.SqlClient.SqlInternalConnectionTds..ctor(DbConnectionPoolIdentity identity, SqlConnectionString connectionOptions, SqlCredential credential, Object providerInfo, String newPassword, SecureString newSecurePassword, Boolean redirectedUserInstance, SqlConnectionString userConnectionOptions, SessionData reconnectSessionData, Boolean applyTransientFaultHandling, String accessToken) at System.Data.SqlClient.SqlConnectionFactory.CreateConnection(DbConnectionOptions options, DbConnectionPoolKey poolKey, Object poolGroupProviderInfo, DbConnectionPool pool, DbConnection owningConnection, DbConnectionOptions userOptions) at System.Data.ProviderBase.DbConnectionFactory.CreatePooledConnection(DbConnectionPool pool, DbConnection owningObject, DbConnectionOptions options, DbConnectionPoolKey poolKey, DbConnectionOptions userOptions) at System.Data.ProviderBase.DbConnectionPool.CreateObject(DbConnection owningObject, DbConnectionOptions userOptions, DbConnectionInternal oldConnection) at System.Data.ProviderBase.DbConnectionPool.UserCreateRequest(DbConnection owningObject, DbConnectionOptions userOptions, DbConnectionInternal oldConnection) at System.Data.ProviderBase.DbConnectionPool.TryGetConnection(DbConnection owningObject, UInt32 waitForMultipleObjectsTimeout, Boolean allowCreate, Boolean onlyOneCheckConnection, DbConnectionOptions userOptions, DbConnectionInternal& connection) at System.Data.ProviderBase.DbConnectionPool.TryGetConnection(DbConnection owningObject, TaskCompletionSource1 retry, DbConnectionOptions userOptions, DbConnectionInternal& connection) at System.Data.ProviderBase.DbConnectionFactory.TryGetConnection(DbConnection owningConnection, TaskCompletionSource1 retry, DbConnectionOptions userOptions, DbConnectionInternal oldConnection, DbConnectionInternal& connection) at System.Data.ProviderBase.DbConnectionInternal.TryOpenConnectionInternal(DbConnection outerConnection, DbConnectionFactory connectionFactory, TaskCompletionSource1 retry, DbConnectionOptions userOptions) at System.Data.SqlClient.SqlConnection.TryOpen(TaskCompletionSource1 retry) at System.Data.SqlClient.SqlConnection.Open() at MobileMetrics.Services.QueryExecutionDAL.SqlDbToolkit.GetData(IList1 dBQueries, IList1 columnDetails) in D:__MM_VNext\Middleware\Main\Source\MobileMetrics.Services\DbToolkit\DbToolkits\SqlDbToolkit.cs:line 172

My connection string used is: Data Source=my-server;Initial Catalog=my-db;UserId=testuser;Password=user@123;Trusted_Connection=False;MultipleActiveResultSets=true

Do I have to install any other package? Or is it something related to a proxy? I have searched a lot in the Internet but there is no luck. Please help me in this regard.

The details are as follows: Host: Linux (RHEL 7) .NET Core: v2.2 Database: SQL Server 2012 Developer Edition IDE: Visual Studio 2017 on Windows 7

Thanks in advance... :)

Answer 1

SQL by default tries windows logins (you knew the world rotated round windows!) even when its an SQL login, despite you saying not trusted, it tries anyway, so on a windows server this often quietly happens in the background, because you already have a kerberos ticket. However, as this is linux, it needs to be told specifically you will not be using any windows based logins, this is done via "Integrated Security=False".