On Mon, Nov 5, 2012 at 2:22 PM, Andrea Giammarchi < [email protected]> wrote:
> not sure I follow the single thread part which I believe isn't bringing > anything new here or maybe I have missed the point. My point was only that, in SES, the attack you showed is only an attack on availability, and so a non-issue. > > What I am saying is that only via that SES "thing", or similar parsers, > SES gets its security without needing to do a full parse. That's part of why it's cheap and reliable. > you might add security but I wonder if the Function, as far as I can tell > being allowed, is able to create runtime potential problems after SES > resulting in opened doors for attacks. > SES replaces the Function constructor with a safe alternative http://code.google.com/p/google-caja/source/browse/trunk/src/com/google/caja/ses/startSES.js#733 > > Anyway, if performance is not an issue then yes, such parser with > whitelist is the least someone should think about but I don't see that > natively implemented, > SES doesn't need to do a full parse. > also because everyone would like to be able to add own namespace in the > list and I believe making a white list modifiable from anyone is again a > security problem. > Making the whitelist modifiable would be fatal. I don't understand your point. > > > On Mon, Nov 5, 2012 at 2:12 PM, Mark S. Miller <[email protected]> wrote: > >> >> On Mon, Nov 5, 2012 at 1:11 PM, Andrea Giammarchi < >> [email protected]> wrote: >> >>> I see security problems all over ... you own your function, you can make >>> it "pure" or serializable ... you don't know your function, I believe >>> there's no way you want that unknown function to be executed in your own >>> sandbox opening doors for any sort of attack, i.e. ... this is pure, no >>> outer scope access at all: function pure() { function(){return >>> this}.call(null).Function.prototype.serialize = function() { /* boom */ } } >> >> >> JavaScript is singly threaded. Within a given JavaScript >> thread/process/worker/vat/whatever, any code which is ever given control >> can just go into an infinite loop or throw, so none of the within-vat >> sandboxes attempt to make any claims about availability[1]. However, SES, >> by following the object-capability model, makes strong claims about >> integrity. Irakli's notion of closed strict functions is adequate for safe >> remote execution, where "safe" means that it can cause no effects on the >> integrity of its importing context not explicitly authorized by the >> references passed into it. >> >> >> [1] MS WebSandbox claimed only resistance to availability accident, not >> to availability attack. >> >> >> >> >>> >>> >>> On Mon, Nov 5, 2012 at 12:19 PM, Herby Vojčík <[email protected]> wrote: >>> >>>> >>>> >>>> Irakli Gozalishvili wrote: >>>> >>>>> Hi, >>>>> >>>>> I keep running into cases where I would like to know if function is >>>>> pure. Although my interpretation of pure is not quite right but I don't >>>>> know any better name. By pure in this context I would refer to >>>>> functions >>>>> that don't access an out scope variables and don't >>>>> do any mutations of itself or it's properties no references to itself >>>>> could be an option too. My intended use case for such a feature is to >>>>> >>>> >>>> IOW, 'stateless'; or 'serializable'. For in fact it means, that I can >>>> send f.toString() to the other side and when evaled, I can use it. >>>> >>>> >>>> processes too, it would be great if we had something like >>>>> Function.isPure(f). Also as far as I know jits already capture this >>>>> info >>>>> for optimisation purposes maybe it could be exposed ? Another >>>>> alternative could be pure(function() { …. }) that would throw compile >>>>> error if >>>>> function followed is not pure. >>>>> >>>> >>>> Yes, it could be nice to have some API to help with this. Maybe not >>>> generic isPure or the like, maybe Function.serialize(f) and >>>> Function.deserialize(**serialized_f) would be enough, the former >>>> returning null if not pure/stateless/serializable. >>>> >>>> It is good to note that the function is serializable not only if it has >>>> no outer pointers, but also when its outer pointers only point to 'known >>>> primitives' (numbers, strings, null, true, false; not symbols). >>>> >>>> >>>> >>>>> Thanks! >>>>> -- >>>>> Irakli Gozalishvili >>>>> Web: http://www.jeditoolkit.com/ >>>>> >>>> >>>> Herby >>>> ______________________________**_________________ >>>> es-discuss mailing list >>>> [email protected] >>>> https://mail.mozilla.org/**listinfo/es-discuss<https://mail.mozilla.org/listinfo/es-discuss> >>>> >>> >>> >>> _______________________________________________ >>> es-discuss mailing list >>> [email protected] >>> https://mail.mozilla.org/listinfo/es-discuss >>> >>> >> >> >> -- >> Cheers, >> --MarkM >> > > -- Cheers, --MarkM
_______________________________________________ es-discuss mailing list [email protected] https://mail.mozilla.org/listinfo/es-discuss
