Freebox Server (Ultra V9/ Pop V8/ Delta V7 / Revolution V6 / Mini 4K)

Il serait cependant plus intéressant que les Freebox intègrent cette signature plus tôt que de passer par un contournement qui désactive cette vérification.

C'est déjà le cas.

C'est juste qu'il est impossible de dériver une clef de signature à partir d'un secret partagé (le mot de passe de l'utilisateur), quand il n'y a pas de mot de passe configuré:

Signing and guest authentication

SMB signing ensures every message contains a signature generated using session key and cipher suite. The client puts a hash of the entire message into the signature field of the SMB header. If anyone changes the message itself later on the wire, the hash won't match, and SMB knows that someone tampered with the data. It also confirms to sender and receiver that they are who they say they are, breaking relay attacks.

To sign a message, the key is derived from a secret both the user client and server share - the user's password. Without that password, the client and server can't sign the SMB traffic because they have no way to validate the sender. And what doesn't a guest logon have? A password. That makes guest authentication > and SMB signing mutually exclusive. When we see that the client requires SMB signing, we don't allow even an attempt at guest authentication, we just fail the connection.

https://techcommunity.microsoft.com/blog/filecab/smb-signing-and-guest-authentication/3846679