[openstack-dev] [Heat] rough draft of Heat autoscaling API

Steven Hardy shardy at redhat.com
Fri Nov 15 10:58:19 UTC 2013

On Fri, Nov 15, 2013 at 11:16:19AM +0100, Zane Bitter wrote:
> On 14/11/13 19:58, Christopher Armstrong wrote:
> >    On 14/11/13 18:51, Randall Burt wrote:
> >
> >        Perhaps, but I also miss important information as a legitimate
> >        caller as
> >        to whether or not my scaling action actually happened or I've been a
> >        little too aggressive with my curl commands. The fact that I get
> >        anything other than 404 (which the spec returns if its not a
> >        legit hook)
> >        means I've found *something* and can simply call it endlessly in
> >        a loop
> >        causing havoc. Perhaps the web hooks *should* be authenticated? This
> >        seems like a pretty large hole to me, especially if I can max
> >        someone's
> >        resources by guessing the right url.
> >
> >
> >    Web hooks MUST be authenticated.
> >
> >
> >
> >Do you mean they should have an X-Auth-Token passed? Or an X-Trust-ID?
> Maybe an X-Auth-Token, though in many cases I imagine it would be
> derived from a Trust. In any event, it should be something provided
> by Keystone because that is where authentication implementations
> belong in OpenStack.
> >The idea was that webhooks are secret (and should generally only be
> >passed around through automated systems, not with human interaction).
> >This is usually how webhooks work, and it's actually how they work now
> >in Heat -- even though there's a lot of posturing about signed requests
> >and so forth, in the end they are literally just secret URLs that give
> >you the capability to perform some operation (if you have the URL, you
> >don't need anything else to execute them). I think we should simplify
> >this to to just be a random revokable blob.
> This is the weakest possible form of security - the whole secret
> gets passed on the wire for every request and logged in innumerable
> places. There's no protection at all against replay attacks (other
> than, hopefully, SSL).
> A signature, a timestamp and a nonce all seem like prudent
> precautions to add.

So maybe we just use tokens and drop the whole pre-signed URL thing -
ceilometer can obtain a token, and call the AS API via the normal method
(i.e a call to a client lib, providing a token)

The main case where tokens are inconvenient is in-instance, where we'll
have to refresh them before they expire (24 hours by default), but
in-instance agents won't talk to the AS API directly, so why don't we just
simplify the discussion and say the AS API has to use normal token auth?


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