244843 - Security exceptions should create an nsScriptError and pass line info

Status: RESOLVED WORKSFORME

(Core :: Security: CAPS, enhancement)

Description

[timeless]

2467 NS_IMETHODIMP
2468 nsScriptSecurityManager::CanCreateInstance(JSContext *cx,
2469                                            const nsCID &aCID)
2470 {
2486         //-- Access denied, report an error
2487         nsCAutoString errorMsg("Permission denied to create instance of
class. CID=");
...
2491         JS_SetPendingException(cx,
2492                                STRING_TO_JSVAL(JS_NewStringCopyZ(cx,
errorMsg.get())));

And similar code for other functions.

problem #0:
this code is very very very very tied to spidermonkey. It shouldn't be.
Either caps should live in js/src/xpconnect/caps or this code should be
rewritten to use some api which hides spidermonkey from caps. That hiding would
enable caps to actually do something useful when a python script wants to get
something it shouldn't.

--
problem #1:
The code just throws a message. XPConnect otoh which has this nice private thing
nsScriptError actually fills in details (line numbers) which enable people to
figure out what's going on.

possible resolutions for problem #1: 
A. xpconnect exposes an xpcom object which is nsScriptError (the interface for
such a thing can live in xpcom) and caps uses it.
B. caps reinvents nsScriptError.

Comment 1

[timeless]

oops, it's not private... i just couldn't find the right comment
NS_SCRIPTERROR_CONTRACTID "@mozilla.org/scripterror;1"

see
http://lxr.mozilla.org/seamonkey/source/content/html/style/src/nsCSSLoader.cpp#683

Comment 2

[Mike Shaver (:shaver emeritus)]

How would you throw the nsScriptError, then?  It's important (very, IMO) that
CAPS generate an exception here, which is only reported to the console if it's
not caught by the calling code.

Comment 3

[timeless]

Probably coerce XPCConvert::ConstructException into special casing nsIScriptError

then use XPCThrower::ThrowExceptionObject

Comment 4

[Brendan Eich [:brendan]]

Confirming.

Timeless, problem #0 is for another bug, and for later.  Caps already knows all
about jsdbgapi.h.  C'mon, prioritize, focus! ;-)

How about a patch for the idea in comment #3?

/be

Comment 5

[Mike Shaver (:shaver emeritus)]

Tying to XPConnect is tying to JS, really, but let's not quibble.