Re: [9fans] security model

[C H Forsyth <forsyth@vitanuova.com>]

> I intsalled  combined cpu/auth server
> I need some explanatories for plan9 security model, because I have
> some troubles with undestanding dependences between factotum,secstore
> and keyfs.
> 
> First I don't undestand why I must run auth/secstored on my auth
> server. In fact keyfs provide to me interface to keys at nvram, and
> secstore provide to me interface to keys at nvram...

there isn't any need to run secstored.  they do quite different things,
though.

secstored securely stores files on behalf of users, in particular a
file "factotum" that holds keys that user wants loaded into the user's
factotum on login.  of course one of those users could be a system
user (eg, "bootes").

you need auth/keyfs though, to hold the per-user shared secrets used
to authenticate them to a plan 9 domain.  it manages /adm/keys.

> Second I don't undestand what means "password" (after "secstore key")
> in auth/wrkey dialog. System password? Who is a "system password"?

it's the shared secret that allows one plan 9 server to authenticate itself to another.
it also encrypts the keys file.  the secstore key is a separate key used by secstored.

> Third I think that I must to add all my permanent auth-server users
> (users with remote terminals) of my "auth domain" to secstore on
> auth-server.

only if you'd like them to use secstore.

: But cpu-server users of THIS cpu-server I must add to
> factotum too.

no, there's a speaks-for relationship configured by /lib/ndb/auth.
see the section on Authentication Database in authsrv(6).

>I must copy some keys from secstore to factotum at boot
> time if I want to grant access to both auth and cpu servers. Am I
> right?

no.  there's no need for users to run factotum; if they don't, they'll be prompted
every time they need to authenticate to something.  if they run factotum, and the key
isn't already in factotum (eg, from secstore), they'll be prompted once.

> Forth why noany ask me to password to access to secstore at boot time?

it got the password from the place that wrkey stored it.