/* 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(); });