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/* 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
const emptyPage =
getRootDirectory(gTestPath).replace(
) + "empty.html";
/**
* workers.
*
* In the test, we create offscreen canvas in workers and test if the extracted
* canvas data is altered because of the canvas randomization.
*/
var TEST_CASES = [
{
name: "CanvasRenderingContext2D.getImageData() with a offscreen canvas",
extractCanvasData: async _ => {
let offscreenCanvas = new OffscreenCanvas(100, 100);
const context = offscreenCanvas.getContext("2d");
context.fillStyle = "#EE2222";
context.fillRect(0, 0, 100, 100);
context.fillStyle = "#2222EE";
context.fillRect(20, 20, 100, 100);
const imageData = context.getImageData(0, 0, 100, 100);
const imageDataSecond = context.getImageData(0, 0, 100, 100);
return [imageData.data, imageDataSecond.data];
},
isDataRandomized: isDataRandomizedFuzzy,
},
{
name: "OffscreenCanvas.convertToBlob() with a 2d context",
extractCanvasData: async _ => {
let offscreenCanvas = new OffscreenCanvas(100, 100);
const context = offscreenCanvas.getContext("2d");
// Draw a red rectangle
context.fillStyle = "#EE2222";
context.fillRect(0, 0, 100, 100);
context.fillStyle = "#2222EE";
context.fillRect(20, 20, 100, 100);
let blob = await offscreenCanvas.convertToBlob();
let data = await new Promise(resolve => {
let fileReader = new FileReader();
fileReader.onload = () => {
resolve(fileReader.result);
};
fileReader.readAsArrayBuffer(blob);
});
let blobSecond = await offscreenCanvas.convertToBlob();
let dataSecond = await new Promise(resolve => {
let fileReader = new FileReader();
fileReader.onload = () => {
resolve(fileReader.result);
};
fileReader.readAsArrayBuffer(blobSecond);
});
return [data, dataSecond];
},
isDataRandomized: isDataRandomizedGreaterThanZero,
},
{
name: "OffscreenCanvas.convertToBlob() with a webgl context",
extractCanvasData: async _ => {
let offscreenCanvas = new OffscreenCanvas(100, 100);
const context = offscreenCanvas.getContext("webgl");
context.enable(context.SCISSOR_TEST);
context.scissor(0, 0, 100, 100);
context.clearColor(1, 0.2, 0.2, 1);
context.clear(context.COLOR_BUFFER_BIT);
context.scissor(15, 15, 30, 15);
context.clearColor(0.2, 1, 0.2, 1);
context.clear(context.COLOR_BUFFER_BIT);
context.scissor(50, 50, 15, 15);
context.clearColor(0.2, 0.2, 1, 1);
context.clear(context.COLOR_BUFFER_BIT);
let blob = await offscreenCanvas.convertToBlob();
let data = await new Promise(resolve => {
let fileReader = new FileReader();
fileReader.onload = () => {
resolve(fileReader.result);
};
fileReader.readAsArrayBuffer(blob);
});
let blobSecond = await offscreenCanvas.convertToBlob();
let dataSecond = await new Promise(resolve => {
let fileReader = new FileReader();
fileReader.onload = () => {
resolve(fileReader.result);
};
fileReader.readAsArrayBuffer(blobSecond);
});
return [data, dataSecond];
},
isDataRandomized: isDataRandomizedGreaterThanZero,
},
{
name: "OffscreenCanvas.convertToBlob() with a bitmaprenderer context",
extractCanvasData: async _ => {
let offscreenCanvas = new OffscreenCanvas(100, 100);
const context = offscreenCanvas.getContext("2d");
// Draw a red rectangle
context.fillStyle = "#EE2222";
context.fillRect(0, 0, 100, 100);
context.fillStyle = "#2222EE";
context.fillRect(20, 20, 100, 100);
const bitmapCanvas = new OffscreenCanvas(100, 100);
let bitmap = await createImageBitmap(offscreenCanvas);
const bitmapContext = bitmapCanvas.getContext("bitmaprenderer");
bitmapContext.transferFromImageBitmap(bitmap);
let blob = await bitmapCanvas.convertToBlob();
let data = await new Promise(resolve => {
let fileReader = new FileReader();
fileReader.onload = () => {
resolve(fileReader.result);
};
fileReader.readAsArrayBuffer(blob);
});
let blobSecond = await bitmapCanvas.convertToBlob();
let dataSecond = await new Promise(resolve => {
let fileReader = new FileReader();
fileReader.onload = () => {
resolve(fileReader.result);
};
fileReader.readAsArrayBuffer(blobSecond);
});
return [data, dataSecond];
},
isDataRandomized: isDataRandomizedGreaterThanZero,
},
];
async function runTest(enabled) {
// Enable/Disable CanvasRandomization by the RFP target overrides.
let RFPOverrides = enabled ? "+CanvasRandomization" : "-CanvasRandomization";
await SpecialPowers.pushPrefEnv({
set: [
["privacy.fingerprintingProtection", true],
["privacy.fingerprintingProtection.pbmode", true],
["privacy.fingerprintingProtection.overrides", RFPOverrides],
["privacy.resistFingerprinting", false],
],
});
// Open a private window.
let privateWindow = await BrowserTestUtils.openNewBrowserWindow({
private: true,
});
// Open tabs in the normal and private window.
const tab = await BrowserTestUtils.openNewForegroundTab(gBrowser, emptyPage);
const privateTab = await BrowserTestUtils.openNewForegroundTab(
privateWindow.gBrowser,
emptyPage
);
for (let test of TEST_CASES) {
info(`Testing ${test.name} in the worker`);
// Clear telemetry before starting test.
Services.fog.testResetFOG();
let data = await await runFunctionInWorker(
tab.linkedBrowser,
test.extractCanvasData
);
let result = test.isDataRandomized(test.name, data[0], test.originalData);
is(
result,
enabled,
`The image data for for '${test.name}' is ${
enabled ? "randomized" : "the same"
}.`
);
ok(
!test.isDataRandomized(test.name, data[0], data[1]),
`The data for '${test.name}' of first and second access should be the same.`
);
let privateData = await await runFunctionInWorker(
privateTab.linkedBrowser,
test.extractCanvasData
);
// Check if we add noise to canvas data in private windows.
result = test.isDataRandomized(
test.name,
privateData[0],
test.originalData,
true
);
is(
result,
enabled,
`The private image data for '${test.name}' is ${
enabled ? "randomized" : "the same"
}.`
);
ok(
!test.isDataRandomized(test.name, privateData[0], privateData[1]),
`"The data for '${test.name}' of first and second access should be the same.`
);
// Make sure the noises are different between normal window and private
// windows.
result = test.isDataRandomized(test.name, privateData[0], data[0]);
is(
result,
enabled,
`The image data for '${
test.name
}' between the normal window and the private window are ${
enabled ? "different" : "the same"
}.`
);
}
// Verify the telemetry is recorded if canvas randomization is enabled.
if (enabled) {
await Services.fog.testFlushAllChildren();
Assert.greater(
Glean.fingerprintingProtection.canvasNoiseCalculateTime.testGetValue()
.sum,
0,
"The telemetry of canvas randomization is recorded."
);
}
BrowserTestUtils.removeTab(tab);
BrowserTestUtils.removeTab(privateTab);
await BrowserTestUtils.closeWindow(privateWindow);
}
add_setup(async function () {
// Disable the fingerprinting randomization.
await SpecialPowers.pushPrefEnv({
set: [
["privacy.fingerprintingProtection", false],
["privacy.fingerprintingProtection.pbmode", false],
["privacy.resistFingerprinting", false],
],
});
// Open a tab for extracting the canvas data in the worker.
const tab = await BrowserTestUtils.openNewForegroundTab(gBrowser, emptyPage);
// Extract the original canvas data without random noise.
for (let test of TEST_CASES) {
let data = await runFunctionInWorker(
tab.linkedBrowser,
test.extractCanvasData
);
test.originalData = data[0];
}
BrowserTestUtils.removeTab(tab);
});
add_task(async function run_tests_with_randomization_enabled() {
await runTest(true);
});
add_task(async function run_tests_with_randomization_disabled() {
await runTest(false);
});