1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
|
/* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
add_task(function instanceof_xrays() {
let sandbox = Cu.Sandbox(null);
Cu.evalInSandbox(`
this.proxy = new Proxy([], {
getPrototypeOf() {
return Date.prototype;
},
});
this.inheritedProxy = Object.create(this.proxy);
this.FunctionProxy = new Proxy(function() {}, {});
this.functionProxyInstance = new this.FunctionProxy();
this.CustomClass = class {};
this.customClassInstance = new this.CustomClass();
`, sandbox);
{
// Sanity check that instanceof still works with standard constructors when xrays are present.
Assert.ok(Cu.evalInSandbox(`new Date()`, sandbox) instanceof sandbox.Date,
"async function result in sandbox instanceof sandbox.Date");
Assert.ok(new sandbox.Date() instanceof sandbox.Date,
"sandbox.Date() instanceof sandbox.Date");
Assert.ok(sandbox.CustomClass instanceof sandbox.Function,
"Class constructor instanceof sandbox.Function");
Assert.ok(sandbox.CustomClass instanceof sandbox.Object,
"Class constructor instanceof sandbox.Object");
// Both operands must have the same kind of Xray vision.
Assert.equal(Cu.waiveXrays(sandbox.CustomClass) instanceof sandbox.Function, false,
"Class constructor with waived xrays instanceof sandbox.Function");
Assert.equal(Cu.waiveXrays(sandbox.CustomClass) instanceof sandbox.Object, false,
"Class constructor with waived xrays instanceof sandbox.Object");
}
{
let {proxy} = sandbox;
Assert.equal(proxy instanceof sandbox.Date, false,
"instanceof should ignore the proxy trap");
Assert.equal(proxy instanceof sandbox.Array, false,
"instanceof should ignore the proxy target");
Assert.equal(Cu.waiveXrays(proxy) instanceof sandbox.Date, false,
"instanceof should ignore the proxy trap despite the waived xrays on the proxy");
Assert.equal(Cu.waiveXrays(proxy) instanceof sandbox.Array, false,
"instanceof should ignore the proxy target despite the waived xrays on the proxy");
Assert.ok(proxy instanceof Cu.waiveXrays(sandbox.Date),
"instanceof should trigger the proxy trap after waiving Xrays on the constructor");
Assert.equal(proxy instanceof Cu.waiveXrays(sandbox.Array), false,
"instanceof should trigger the proxy trap after waiving Xrays on the constructor");
Assert.ok(Cu.waiveXrays(proxy) instanceof Cu.waiveXrays(sandbox.Date),
"instanceof should trigger the proxy trap after waiving both Xrays");
}
{
let {inheritedProxy} = sandbox;
Assert.equal(inheritedProxy instanceof sandbox.Date, false,
"instanceof should ignore the inherited proxy trap");
Assert.equal(Cu.waiveXrays(inheritedProxy) instanceof sandbox.Date, false,
"instanceof should ignore the inherited proxy trap despite the waived xrays on the proxy");
Assert.ok(inheritedProxy instanceof Cu.waiveXrays(sandbox.Date),
"instanceof should trigger the inherited proxy trap after waiving Xrays on the constructor");
Assert.ok(Cu.waiveXrays(inheritedProxy) instanceof Cu.waiveXrays(sandbox.Date),
"instanceof should trigger the inherited proxy trap after waiving both Xrays");
}
{
let {FunctionProxy, functionProxyInstance} = sandbox;
// Ideally, the next two test cases should both throw "... not a function".
// However, because the opaque XrayWrapper does not override isCallable, an
// opaque XrayWrapper is still considered callable if the proxy target is,
// and "instanceof" will try to look up the prototype of the wrapper (and
// fail because opaque XrayWrappers hide the properties).
Assert.throws(
() => functionProxyInstance instanceof FunctionProxy,
/'prototype' property of FunctionProxy is not an object/,
"Opaque constructor proxy should be hidden by Xrays");
Assert.throws(
() => functionProxyInstance instanceof sandbox.proxy,
/sandbox.proxy is not a function/,
"Opaque non-constructor proxy should be hidden by Xrays");
Assert.ok(functionProxyInstance instanceof Cu.waiveXrays(FunctionProxy),
"instanceof should get through the proxy after waiving Xrays on the constructor proxy");
Assert.ok(Cu.waiveXrays(functionProxyInstance) instanceof Cu.waiveXrays(FunctionProxy),
"instanceof should get through the proxy after waiving both Xrays");
}
{
let {CustomClass, customClassInstance} = sandbox;
// Under Xray vision, every JS object is either a plain object or array.
// Prototypical inheritance is invisible when the constructor is wrapped.
Assert.throws(
() => customClassInstance instanceof CustomClass,
/TypeError: 'prototype' property of CustomClass is not an object/,
"instanceof on a custom JS class with xrays should fail");
Assert.ok(customClassInstance instanceof Cu.waiveXrays(CustomClass),
"instanceof should see the true prototype of CustomClass after waiving Xrays on the class");
Assert.ok(Cu.waiveXrays(customClassInstance) instanceof Cu.waiveXrays(CustomClass),
"instanceof should see the true prototype of CustomClass after waiving Xrays");
}
});
add_task(function instanceof_dom_xrays_hasInstance() {
const principal = Services.scriptSecurityManager.createNullPrincipal({});
const webnav = Services.appShell.createWindowlessBrowser(false);
webnav.docShell.createAboutBlankContentViewer(principal, principal);
let window = webnav.document.defaultView;
let sandbox = Cu.Sandbox(principal);
sandbox.DOMObjectWithHasInstance = window.document;
Cu.evalInSandbox(`
this.DOMObjectWithHasInstance[Symbol.hasInstance] = function() {
return true;
};
this.ObjectWithHasInstance = {
[Symbol.hasInstance](v) {
v.throwsIfVCannotBeAccessed;
return true;
},
};
`, sandbox);
// Override the hasInstance handler in the window, so that we can detect when
// we end up triggering hasInstance in the window's compartment.
window.eval(`
document[Symbol.hasInstance] = function() {
throw "hasInstance_in_window";
};
`);
sandbox.domobj = window.document.body;
Assert.ok(sandbox.eval(`domobj.wrappedJSObject`),
"DOM object is a XrayWrapper");
Assert.ok(sandbox.eval(`DOMObjectWithHasInstance.wrappedJSObject`),
"DOM object with Symbol.hasInstance is a XrayWrapper");
for (let Obj of ["ObjectWithHasInstance", "DOMObjectWithHasInstance"]) {
// Tests Xray vision *inside* the sandbox. The Symbol.hasInstance member
// is a property / expando object in the sandbox's compartment, so the
// "instanceof" operator should always trigger the hasInstance function.
Assert.ok(sandbox.eval(`[] instanceof ${Obj}`),
`Should call ${Obj}[Symbol.hasInstance] when left operand has no Xrays`);
Assert.ok(sandbox.eval(`domobj instanceof ${Obj}`),
`Should call ${Obj}[Symbol.hasInstance] when left operand has Xrays`);
Assert.ok(sandbox.eval(`domobj.wrappedJSObject instanceof ${Obj}`),
`Should call ${Obj}[Symbol.hasInstance] when left operand has waived Xrays`);
// Tests Xray vision *outside* the sandbox. The Symbol.hasInstance member
// should be hidden by Xrays.
let sandboxObjWithHasInstance = sandbox[Obj];
Assert.ok(Cu.isXrayWrapper(sandboxObjWithHasInstance),
`sandbox.${Obj} is a XrayWrapper`);
Assert.throws(
() => sandbox.Object() instanceof sandboxObjWithHasInstance,
/sandboxObjWithHasInstance is not a function/,
`sandbox.${Obj}[Symbol.hasInstance] should be hidden by Xrays`);
Assert.throws(
() => Cu.waiveXrays(sandbox.Object()) instanceof sandboxObjWithHasInstance,
/sandboxObjWithHasInstance is not a function/,
`sandbox.${Obj}[Symbol.hasInstance] should be hidden by Xrays, despite the waived Xrays at the left`);
// (Cases where the left operand has no Xrays are checked below.)
}
// hasInstance is expected to be called, but still trigger an error because
// properties of the object from the current context should not be readable
// by the hasInstance function in the sandbox with a different principal.
Assert.throws(
() => [] instanceof Cu.waiveXrays(sandbox.ObjectWithHasInstance),
/Permission denied to access property "throwsIfVCannotBeAccessed"/,
`Should call (waived) sandbox.ObjectWithHasInstance[Symbol.hasInstance] when the right operand has waived Xrays`);
// The Xray waiver on the right operand should be sufficient to call
// hasInstance even if the left operand still has Xrays.
Assert.ok(sandbox.Object() instanceof Cu.waiveXrays(sandbox.ObjectWithHasInstance),
`Should call (waived) sandbox.ObjectWithHasInstance[Symbol.hasInstance] when the right operand has waived Xrays`);
Assert.ok(Cu.waiveXrays(sandbox.Object()) instanceof Cu.waiveXrays(sandbox.ObjectWithHasInstance),
`Should call (waived) sandbox.ObjectWithHasInstance[Symbol.hasInstance] when both operands have waived Xrays`);
// When Xrays of the DOM object are waived, we end up in the owner document's
// compartment (instead of the sandbox).
Assert.throws(
() => [] instanceof Cu.waiveXrays(sandbox.DOMObjectWithHasInstance),
/hasInstance_in_window/,
"Should call (waived) sandbox.DOMObjectWithHasInstance[Symbol.hasInstance] when the right operand has waived Xrays");
Assert.throws(
() => Cu.waiveXrays(sandbox.Object()) instanceof Cu.waiveXrays(sandbox.DOMObjectWithHasInstance),
/hasInstance_in_window/,
"Should call (waived) sandbox.DOMObjectWithHasInstance[Symbol.hasInstance] when both operands have waived Xrays");
webnav.close();
});
|
