using System;

using System.Collections.Generic;   

using System.Linq;

public class Program

{

    public static void Main()

    {

        Console.WriteLine("Hello World");

         List<string> KnownAuthenticationErrors = new List<string>

                                    {

                                        "invalid_grant",

                                        "AADB2C90090" //Error code for AADB2C90090: The specified kid 'cpimcore_09252015' is not found for JWE

                                    };

        var errorMsg="contains error: 'invalid_grant', error_description: 'AADB2C90090: The specified kid 'Atr3vKL53_F8HNXgDjYGROG0d6etyWOk7vV-Ok0dkYk' is not found for JWE.";

        var isKnownError = KnownAuthenticationErrors.Any(error => errorMsg.Contains(error, StringComparison.OrdinalIgnoreCase) == true)

            || KnownAuthenticationErrors.Any(error => errorMsg.Contains(error, StringComparison.OrdinalIgnoreCase) == true);

​

​

    Console.WriteLine($"IsKnown {isKnownError}");

​

​

    }

}