I’m writing a service that will fetch users from Active Directory server (on-premise, but I am not sure if this is relevant)

The code is written in C#.
I’m using an LDAP connection like this:

var authType = AuthType.Basic;
var connection = new LdapConnection(
new LdapDirectoryIdentifier(hostNameOrIP, portNumber),
new System.Net.NetworkCredential(userName, password, domain), authType);
connection.SessionOptions.ProtocolVersion = 3;
connection.Bind();

I can get Users from Active Directory, but when I try to parse the “objectguid” attribute from a user from Base64 to string I get “junk”

"objectguid": [
   "jNXa6wSDYU6cy4peVH8GuQ=="
],

I read this post: /questions/74153453/how-to-get-objectsid-value-programmaticaly-from-active-directory

and I understand that the objectguid is a value in binary and base64 encoded

I tried to convert the script in the post to C# using chatGPT and i got this code:

```
    private void Test()
    {
        try
        {
            string base64ObjectSid = "jNXa6wSDYU6cy4peVH8GuQ==";

            // Decode base64 to byte array
            byte[] objectSidBytes = Convert.FromBase64String(base64ObjectSid);

            // Extract components from the byte array
            int revision = objectSidBytes[0];
            int subAuthorityCount = objectSidBytes[1];

            // Construct the SID string
            string sidString = $"S-{revision}-{objectSidBytes[7]}";


            for (int i = 0; i < subAuthorityCount; i++)
            {
                int subAuthorityStartIndex = 8 + i * 4;
                uint subAuthorityValue = BitConverter.ToUInt32(objectSidBytes, subAuthorityStartIndex);
                sidString += $"-{subAuthorityValue}";
            }

            Console.WriteLine($"UserName: {userName}, Decoded SID: {sidString}");
        }
        catch (Exception ex)
        {
            string err = ex.ToString();
        }

    }

but it doesn't work. I get an exception :

{"Index was out of range. It must be non-negative and less than the size of the collection. (Parameter 'startIndex')"}



Does anyone know how to parse the "objectguid" value from AD to a readable string?

thanks