That’s complicated to do correctly. Normally, for the server to verify the user has the correct password, it needs to know or receive the password, at which point it could decrypt all the user’s files. They’d need to implement something like SRP.
Update: I contacted the developers to bring my comment to their attention and it turns out they have already implemented SRP to address this problem (but they haven’t updated their architecture document about it yet).
That’s complicated to do correctly. Normally, for the server to verify the user has the correct password, it needs to know or receive the password, at which point it could decrypt all the user’s files. They’d need to implement something like SRP.
Update: I contacted the developers to bring my comment to their attention and it turns out they have already implemented SRP to address this problem (but they haven’t updated their architecture document about it yet).