tor-browser

featurepolicy.js (18645B)

---

// Feature test to avoid timeouts
function assert_feature_policy_supported() {
 assert_not_equals(document.featurePolicy, undefined,
                   'Feature Policy is supported');
}
// Tests whether a feature that is enabled/disabled by feature policy works
// as expected.
// Arguments:
//    feature_description: a short string describing what feature is being
//        tested. Examples: "usb.GetDevices()", "PaymentRequest()".
//    test: test created by testharness. Examples: async_test, promise_test.
//    src: URL where a feature's availability is checked. Examples:
//        "/feature-policy/resources/feature-policy-payment.html",
//        "/feature-policy/resources/feature-policy-usb.html".
//    expect_feature_available: a callback(data, feature_description) to
//        verify if a feature is available or unavailable as expected.
//        The file under the path "src" defines what "data" is sent back as a
//        postMessage. Inside the callback, some tests (e.g., EXPECT_EQ,
//        EXPECT_TRUE, etc) are run accordingly to test a feature's
//        availability.
//        Example: expect_feature_available_default(data, feature_description).
//    feature_name: Optional argument, only provided when testing iframe allow
//      attribute. "feature_name" is the feature name of a policy controlled
//      feature (https://wicg.github.io/feature-policy/#features).
//      See examples at:
//      https://github.com/WICG/feature-policy/blob/master/features.md
//    allow_attribute: Optional argument, only used for testing fullscreen
//      by passing "allowfullscreen".
function test_feature_availability(
   feature_description, test, src, expect_feature_available, feature_name,
   allow_attribute) {
 let frame = document.createElement('iframe');
 frame.src = src;

 if (typeof feature_name !== 'undefined') {
   frame.allow = frame.allow.concat(";" + feature_name);
 }

 if (typeof allow_attribute !== 'undefined') {
   frame.setAttribute(allow_attribute, true);
 }

 window.addEventListener('message', test.step_func(function handler(evt) {
   if (evt.source === frame.contentWindow) {
     expect_feature_available(evt.data, feature_description);
     document.body.removeChild(frame);
     window.removeEventListener('message', handler);
     test.done();
   }
 }));

 document.body.appendChild(frame);
}

// Default helper functions to test a feature's availability:
function expect_feature_available_default(data, feature_description) {
 assert_true(data.enabled, feature_description);
}

function expect_feature_unavailable_default(data, feature_description) {
 assert_false(data.enabled, feature_description);
}

// This is the same as test_feature_availability() but instead of passing in a
// function to check the result of the message sent back from an iframe, instead
// just compares the result to an expected result passed in.
// Arguments:
//     test: test created by testharness. Examples: async_test, promise_test.
//     src: the URL to load in an iframe in which to test the feature.
//     expected_result: the expected value to compare to the data passed back
//         from the src page by postMessage.
//     allow_attribute: Optional argument, only provided when an allow
//         attribute should be specified on the iframe.
function test_feature_availability_with_post_message_result(
   test, src, expected_result, allow_attribute) {
 var test_result = function(data, feature_description) {
   assert_equals(data, expected_result);
 };
 test_feature_availability(null, test, src, test_result, allow_attribute);
}

// If this page is intended to test the named feature (according to the URL),
// tests the feature availability and posts the result back to the parent.
// Otherwise, does nothing.
function test_feature_in_iframe(feature_name, feature_promise_factory) {
 if (location.hash.endsWith(`#${feature_name}`)) {
   feature_promise_factory().then(
       () => window.parent.postMessage('#OK', '*'),
       (e) => window.parent.postMessage('#' + e.name, '*'));
 }
}

// Returns true if the URL for this page indicates that it is embedded in an
// iframe.
function page_loaded_in_iframe() {
 return location.hash.startsWith('#iframe');
}

// Returns a same-origin (relative) URL suitable for embedding in an iframe for
// testing the availability of the feature.
function same_origin_url(feature_name) {
 // Append #iframe to the URL so we can detect the iframe'd version of the
 // page.
 return location.pathname + '#iframe#' + feature_name;
}

// Returns a cross-origin (absolute) URL suitable for embedding in an iframe for
// testing the availability of the feature.
function cross_origin_url(base_url, feature_name) {
 return base_url + same_origin_url(feature_name);
}

// This function runs all feature policy tests for a particular feature that
// has a default policy of "self". This includes testing:
// 1. Feature usage succeeds by default in the top level frame.
// 2. Feature usage succeeds by default in a same-origin iframe.
// 3. Feature usage fails by default in a cross-origin iframe.
// 4. Feature usage suceeds when an allow attribute is specified on a
//    cross-origin iframe.
//
// The same page which called this function will be loaded in the iframe in
// order to test feature usage there. When this function is called in that
// context it will simply run the feature and return a result back via
// postMessage.
//
// Arguments:
//     cross_origin: A cross-origin URL base to be used to load the page which
//         called into this function.
//     feature_name: The name of the feature as it should be specified in an
//         allow attribute.
//     error_name: If feature usage does not succeed, this is the string
//         representation of the error that will be passed in the rejected
//         promise.
//     feature_promise_factory: A function which returns a promise which tests
//         feature usage. If usage succeeds, the promise should resolve. If it
//         fails, the promise should reject with an error that can be
//         represented as a string.
function run_all_fp_tests_allow_self(
   cross_origin, feature_name, error_name, feature_promise_factory) {
 // This may be the version of the page loaded up in an iframe. If so, just
 // post the result of running the feature promise back to the parent.
 if (page_loaded_in_iframe()) {
   test_feature_in_iframe(feature_name, feature_promise_factory);
   return;
 }

 // Run the various tests.
 // 1. Allowed in top-level frame.
 promise_test(
     () => feature_promise_factory(),
     'Default "' + feature_name +
         '" feature policy ["self"] allows the top-level document.');

 // 2. Allowed in same-origin iframe.
 const same_origin_frame_pathname = same_origin_url(feature_name);
 async_test(
     t => {
       test_feature_availability_with_post_message_result(
           t, same_origin_frame_pathname, '#OK');
     },
     'Default "' + feature_name +
         '" feature policy ["self"] allows same-origin iframes.');

 // 3. Blocked in cross-origin iframe.
 const cross_origin_frame_url = cross_origin_url(cross_origin, feature_name);
 async_test(
     t => {
       test_feature_availability_with_post_message_result(
           t, cross_origin_frame_url, '#' + error_name);
     },
     'Default "' + feature_name +
         '" feature policy ["self"] disallows cross-origin iframes.');

 // 4. Allowed in cross-origin iframe with "allow" attribute.
 async_test(
     t => {
       test_feature_availability_with_post_message_result(
           t, cross_origin_frame_url, '#OK', feature_name);
     },
     'Feature policy "' + feature_name +
         '" can be enabled in cross-origin iframes using "allow" attribute.');
}

// This function runs all feature policy tests for a particular feature that
// has a default policy of "*". This includes testing:
// 1. Feature usage succeeds by default in the top level frame.
// 2. Feature usage succeeds by default in a same-origin iframe.
// 3. Feature usage succeeds by default in a cross-origin iframe.
// 4. Feature usage fails when an allow attribute is specified on a
//    cross-origin iframe with a value of "feature-name 'none'".
//
// The same page which called this function will be loaded in the iframe in
// order to test feature usage there. When this function is called in that
// context it will simply run the feature and return a result back via
// postMessage.
//
// Arguments:
//     cross_origin: A cross-origin URL base to be used to load the page which
//         called into this function.
//     feature_name: The name of the feature as it should be specified in an
//         allow attribute.
//     error_name: If feature usage does not succeed, this is the string
//         representation of the error that will be passed in the rejected
//         promise.
//     feature_promise_factory: A function which returns a promise which tests
//         feature usage. If usage succeeds, the promise should resolve. If it
//         fails, the promise should reject with an error that can be
//         represented as a string.
function run_all_fp_tests_allow_all(
   cross_origin, feature_name, error_name, feature_promise_factory) {
 // This may be the version of the page loaded up in an iframe. If so, just
 // post the result of running the feature promise back to the parent.
 if (page_loaded_in_iframe()) {
   test_feature_in_iframe(feature_name, feature_promise_factory);
   return;
 }

 // Run the various tests.
 // 1. Allowed in top-level frame.
 promise_test(
     () => feature_promise_factory(),
     'Default "' + feature_name +
         '" feature policy ["*"] allows the top-level document.');

 // 2. Allowed in same-origin iframe.
 const same_origin_frame_pathname = same_origin_url(feature_name);
 async_test(
     t => {
       test_feature_availability_with_post_message_result(
           t, same_origin_frame_pathname, '#OK');
     },
     'Default "' + feature_name +
         '" feature policy ["*"] allows same-origin iframes.');

 // 3. Allowed in cross-origin iframe.
 const cross_origin_frame_url = cross_origin_url(cross_origin, feature_name);
 async_test(
     t => {
       test_feature_availability_with_post_message_result(
           t, cross_origin_frame_url, '#OK');
     },
     'Default "' + feature_name +
         '" feature policy ["*"] allows cross-origin iframes.');

 // 4. Blocked in cross-origin iframe with "allow" attribute set to 'none'.
 async_test(
     t => {
       test_feature_availability_with_post_message_result(
           t, cross_origin_frame_url, '#' + error_name,
           feature_name + " 'none'");
     },
     'Feature policy "' + feature_name +
         '" can be disabled in cross-origin iframes using "allow" attribute.');

 // 5. Blocked in same-origin iframe with "allow" attribute set to 'none'.
 async_test(
     t => {
       test_feature_availability_with_post_message_result(
           t, same_origin_frame_pathname, '#' + error_name,
           feature_name + " 'none'");
     },
     'Feature policy "' + feature_name +
         '" can be disabled in same-origin iframes using "allow" attribute.');
}

// This function tests that a given policy allows each feature for the correct
// list of origins specified by the |expected_policy|.
// Arguments:
//     expected_policy: A list of {feature, allowlist} pairs where the feature is
//         enabled for every origin in the allowlist, in the |policy|.
//     policy: Either a document.featurePolicy or an iframe.featurePolicy to be
//         tested.
//     message: A short description of what policy is being tested.
function test_allowlists(expected_policy, policy, message) {
 for (var allowlist of allowlists) {
   test(function() {
     assert_array_equals(
       policy.getAllowlistForFeature(allowlist.feature),
       allowlist.allowlist);
   }, message + ' for feature ' + allowlist.feature);
 }
}

// This function tests that a subframe's document policy allows a given feature.
// A feature is allowed in a frame either through inherited policy or specified
// by iframe allow attribute.
// Arguments:
//     test: test created by testharness. Examples: async_test, promise_test.
//     feature: feature name that should be allowed in the frame.
//     src: the URL to load in the frame.
//     allow: the allow attribute (container policy) of the iframe
function test_allowed_feature_for_subframe(message, feature, src, allow) {
 let frame = document.createElement('iframe');
 if (typeof allow !== 'undefined') {
   frame.allow = allow;
 }
 promise_test(function() {
   assert_feature_policy_supported();
   frame.src = src;
   return new Promise(function(resolve, reject) {
     window.addEventListener('message', function handler(evt) {
       resolve(evt.data);
     }, { once: true });
     document.body.appendChild(frame);
   }).then(function(data) {
     assert_true(data.includes(feature), feature);
   });
 }, message);
}

// This function tests that a subframe's document policy disallows a given
// feature. A feature is allowed in a frame either through inherited policy or
// specified by iframe allow attribute.
// Arguments:
//     test: test created by testharness. Examples: async_test, promise_test.
//     feature: feature name that should not be allowed in the frame.
//     src: the URL to load in the frame.
//     allow: the allow attribute (container policy) of the iframe
function test_disallowed_feature_for_subframe(message, feature, src, allow) {
 let frame = document.createElement('iframe');
 if (typeof allow !== 'undefined') {
   frame.allow = allow;
 }
 promise_test(function() {
   assert_feature_policy_supported();
   frame.src = src;
   return new Promise(function(resolve, reject) {
     window.addEventListener('message', function handler(evt) {
       resolve(evt.data);
     }, { once: true });
     document.body.appendChild(frame);
   }).then(function(data) {
     assert_false(data.includes(feature), feature);
   });
 }, message);
}

// This function tests that a subframe with header policy defined on a given
// feature allows and disallows the feature as expected.
// Arguments:
//     feature: feature name.
//     frame_header_policy: either *, 'self' or 'none', defines the frame
//                          document's header policy on |feature|.
//     src: the URL to load in the frame.
//     test_expects: contains 6 expected results of either |feature| is allowed
//                   or not inside of a local or remote iframe nested inside
//                   the subframe given the header policy to be either *,
//                   'slef', or 'none'.
//     test_name: name of the test.
function test_subframe_header_policy(
   feature, frame_header_policy, src, test_expects, test_name) {
 let frame = document.createElement('iframe');
 promise_test(function() {
   assert_feature_policy_supported()
   frame.src = src + '?pipe=sub|header(Feature-Policy,' + feature + ' '
       + frame_header_policy + ';)';
   return new Promise(function(resolve) {
     window.addEventListener('message', function handler(evt) {
       resolve(evt.data);
     });
     document.body.appendChild(frame);
   }).then(function(results) {
     for (var j = 0; j < results.length; j++) {
       var data = results[j];

       function test_result(message, test_expect) {
         if (test_expect) {
           assert_true(data.allowedfeatures.includes(feature), message);
         } else {
           assert_false(data.allowedfeatures.includes(feature), message);
         }
       }

       if (data.frame === 'local') {
         if (data.policy === '*') {
           test_result('local_all:', test_expects.local_all);
         }
         if (data.policy === '\'self\'') {
           test_result('local_self:', test_expects.local_self);
         }
         if (data.policy === '\'none\'') {
           test_result('local_none:', test_expects.local_none);
         }
       }

       if (data.frame === 'remote') {
         if (data.policy === '*') {
           test_result('remote_all:', test_expects.remote_all);
         }
         if (data.policy === '\'self\'') {
           test_result('remote_self:', test_expects.remote_self);
         }
         if (data.policy === '\'none\'') {
           test_result('remote_none:', test_expects.remote_none);
         }
       }
     }
   });
 }, test_name);
}

// This function tests that frame policy allows a given feature correctly. A
// feature is allowed in a frame either through inherited policy or specified
// by iframe allow attribute.
// Arguments:
//     feature: feature name.
//     src: the URL to load in the frame. If undefined, the iframe will have a
//         srcdoc="" attribute
//     test_expect: boolean value of whether the feature should be allowed.
//     allow: optional, the allow attribute (container policy) of the iframe.
//     allowfullscreen: optional, boolean value of allowfullscreen attribute.
//     sandbox: optional boolean. If true, the frame will be sandboxed (with
//         allow-scripts, so that tests can run in it.)
function test_frame_policy(
   feature, src, srcdoc, test_expect, allow, allowfullscreen, sandbox) {
 let frame = document.createElement('iframe');
 document.body.appendChild(frame);
 // frame_policy should be dynamically updated as allow and allowfullscreen is
 // updated.
 var frame_policy = frame.featurePolicy;
 if (typeof allow !== 'undefined') {
   frame.setAttribute('allow', allow);
 }
 if (!!allowfullscreen) {
   frame.setAttribute('allowfullscreen', true);
 }
 if (!!sandbox) {
   frame.setAttribute('sandbox', 'allow-scripts');
 }
 if (!!src) {
   frame.src = src;
 }
 if (!!srcdoc) {
   frame.srcdoc = "<h1>Hello world!</h1>";
 }
 if (test_expect) {
   assert_true(frame_policy.allowedFeatures().includes(feature));
 } else {
   assert_false(frame_policy.allowedFeatures().includes(feature));
 }
}

function expect_reports(report_count, policy_name, description) {
 async_test(t => {
   var num_received_reports = 0;
   new ReportingObserver(t.step_func((reports, observer) => {
       const relevant_reports = reports.filter(r => (r.body.featureId === policy_name));
       num_received_reports += relevant_reports.length;
       if (num_received_reports >= report_count) {
           t.done();
       }
  }), {types: ['permissions-policy-violation'], buffered: true}).observe();
 }, description);
}