Re: RFC: KEYS: Is this too-big a behavioural change for a systemcall?

From: James Morris
Date: Thu Jan 30 2014 - 20:03:29 EST


On Thu, 30 Jan 2014, David Howells wrote:

> (5) Don't implicitly create a new anonymous keyring and don't implicitly set
> the session keyring to the user-session keyring, but rather just fall back
> to using the user-session keyring if there isn't a session keyring.
>

>
> That said, I do think that the Kerberos people have a valid point. The current
> behaviour is poor. I'm inclined to implement (5) or (6), probably (5).
>
> This won't make any difference to most processes, ie.:
>
> (*) Those run from pam_keyinit-managed login shells.
>
> (*) Those that don't make use of libkrb5 or keyrings.
>

So there are existing apps which will see semantic changes?

If so, we can't accept this change.

> In many ways, I'd like to just get rid of the user and user-session keyrings
> from the kernel entirely and have them created and maintained by pam_keyinit.
> The special keyring IDs:
>
> KEY_SPEC_USER_KEYRING
> KEY_SPEC_USER_SESSION_KEYRING
>
> and:
>
> KEY_REQKEY_DEFL_USER_KEYRING
> KEY_REQKEY_DEFL_USER_SESSION_KEYRING
>
> would then search your session keyring for keyrings called "_uid" and
> "_uid_ses" and return those. Unfortunately, I think this is probably a
> much-too-big change at this point.
>
> Any thoughts?

Getting it right is more important than the size of the change.

What about creating a new system call with the desired behavior, and
deprecating the current one (or at least, making it a wrapper for the new
call).

--
James Morris
<jmorris@xxxxxxxxx>
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