Windows 10 connection to Ubuntu network share (security policy error)

Issue

With Windows 10 version 1709 (or later), it is possible to receive an error message when connecting to Ubuntu 22.04 RIP network shares (as public) and saving. The reason is that, according to the latest network policies, Windows no longer allows guest account access.

More details in the documentation of Windows Server: How to enable insecure guest logons in SMB2 and SMB3?

Problem

Potential error screen when attempting to access the CalderaRIP (in this example the RIP IP address is 10.10.10.221) from the Windows start menu, by entering \\10.10.10.221:

The reason for this is the following default Samba entry (/etc/samba/smb.conf)

map to guest = bad user

This is because Windows tries to log in with the current Windows username by default. If that doesn't work, it maps as a guest on the Ubuntu server side, triggering the security error (as that is something the latest Windows network policies do not allow).

Solution
(Confirmed to work with Windows 10 Pro, build 10.0.19045, and Ubuntu 22.04 with CalderaDock 2.1.0 + Setup Tools installed).

Prerequisite: Setup Tools must be installed on Ubuntu using CalderaDock, as this install Samba and the smb.conf file with the CalderaRIP-specific share information:

1. Open as root smb.conf, and comment out map to guest = bad user
   
   
2. Using Terminal and Nano as editor:
   sudo nano /etc/samba/smb.conf
   
   
   
3. Then browse (using the keyboard arrows):
   
   
   
4. And add the # to disable the map to guest = bad user
   
   
   
5. Go to the Global section and write:  security = user
6. Go to the Public section and write: "guest ok = no" and "valid users = caldera"
7. Go to the Save section and write: "guest ok = no" and "valid users = caldera"
8. Then save the changes with CTRL+X (confirm with yes and leave the smb.conf as is).
   
   
9. Restart the samba service to reflect the changes made in the smb.conf file:
   sudo /etc/init.d/smbd restart
   
   
   
10. Run the following command line in the terminal: sudo apt-get install libpam-winbind 
11. Next is to add "caldera" as a samba user with a valid password (use for example caldera as user and caldera as password): sudo smbpasswd -a caldera
    
    
12. Now you should be able to login as the Caldera user from Windows (it will show a login window instead of the error popup) and it then allows you to enter the username and password as defined in the previous step (please see the pictures below image 1 and image 2 ).

Image 1

Image 2