On 8 November 2011 18:47, David Bruant <bruan...@gmail.com> wrote: > "Given that direct proxies are not in a position to violate any of the > *non-configurability or non-extensibility constraints* of their wrapped > target, it should be safe to replace an existing normal object by a > direct proxy wrapping that object." > My understanding is that regarding the issue you mention, you cannot do > more with startTrapping than redefining built-ins by (re)setting a property.
That may be true for plain objects, but I think the situation is quite different for functions, because there is no equivalent to "non-configurable" for the [[Call]] and [[Construct]] properties. On 8 November 2011 19:13, Mark S. Miller <erig...@google.com> wrote: > The reason Proxy.attach may not be fatal is that it only allows attachment > to extensible objects. Our hypothesis is that any ES5 object that is > interested in defending itself has already made itself non-extensible. This > is why we must key this off of non-extensibility, rather than introducing a > new orthogonal bit -- to avoid breaching the defenses of those ES5 era > objects that tried to defend themselves. I don't think that addresses the issue I was describing. The problem is: the object itself can all be frozen, non-extensible, non-attachable just fine, but that doesn't achieve much by itself anymore because an attacker can still attach to each individual method, since they are entirely separate objects! So instead of just freezing an object, you _additionally_ would have to make all its _individual methods_ non-attachable (by whatever means). AFAICS, that affects assumptions of existing ES5 code quite severely. /Andreas _______________________________________________ es-discuss mailing list es-discuss@mozilla.org https://mail.mozilla.org/listinfo/es-discuss
