MySQL Bugs: #115934: MySql Connector .NET - Windows Authentication Failure

Bug #115934	MySql Connector .NET - Windows Authentication Failure
Submitted:	26 Aug 2024 17:54	Modified:	30 Aug 2024 6:21
Reporter:	Jeff Danner	Email Updates:
Status:	Verified	Impact on me:	None
Category:	Connector / NET	Severity:	S3 (Non-critical)
Version:	9.0.0	OS:	Windows
Assigned to:		CPU Architecture:	Any
Tags:	Windows Authentication

Description:
I cannot connect to MySql/MariaDB with Windows Authentication using MySql Connector (MySql.Data v9.0.0).

I can connect with the same Windows AD service account using HeidiSQL.

How to repeat:
Connecting to MySql/MaraDB with Windows Authentication. I created a simple test console app in C#.
MySqlConnectionStringBuilder creates invalid connection string; "Integrated Security=True" not "IntegratedSecurity=yes" required per the documentation.

I attempted to just make the connection string as a string loteral:  server=MyServer;database=MyDatabase;IntegratedSecurity=yes;port=3306

I passed that into the MySqlConnection constructor:
using (MySqlConnection connection = new MySqlConnection("server=MyServer;database=MyDatabase;IntegratedSecurity=yes;port=3306"))
{
 Console.WriteLine($"Connection object connection string: {connection.ConnectionString}");
connection.Open();
}

OUTPUT:

Connection object connection string: server=MyServerdatabase=MyDatabase;Integrated Security=True;port=3306

Authentication to host 'MyServerdatabase' for user 'MyUser' using method 'mysql_native_password' failed with message: Access denied for user 'auth_windows'@'MyLocalServer' (using password: NO) 

Yet I can connect with the Windws AD account using HeidiSQL on the test server, logged in as the AD service account

Suggested fix:
Change MySqlConnectionStringBuilder to generate the correct connection string and change the MySqlConnection to NOT alter a valid connection string

Hello Jeff Danner,

Thank you for the bug report and feedback.
Could you please provide a repeatable test case (sample console app in c# which manifest the issue - please make it as private if you prefer) to reproduce this issue at our end? Thank you.

Regards,
Umesh

Thank you for providing requested details.

regards,
Umesh

Thank you for the test case.