Thank you for the work on this extension. I understand the idea and the simplicity, and laud the work that went into it.
Ideally, security should be composed of these visible little file connectors like you have here. They’re auditable near by definition (external calls,obfuscation,hidden exploits).
The main issue, and a sad state of affairs today, is hardware based security devices or “enclaves”. These are all closed, and many big players lock them down.
Ideally, the TOTP key should be stored in an enclave to reduce the chance of a key leaking. Master key is nice, but it’s still a software control on an assumed compromised system.
With that said, isn’t the whole benefit of TOTP the human interaction? If I see one browsers request login, then the code comes from the keyboard, it’s difficult to use that code again. If there is a keylogger you get one session. When it’s stored locally, you can automate it and login from anywhere once you crack or sniff the master password.
I really like this type of security, it’s likely the future, but the entrenched industry makes securing properly by anyone who isn’t a big player very difficult.
Passkeys try to get around this by making them disposable per device locked in an enclave. Hardware assurance is a roadblock.