-
Notifications
You must be signed in to change notification settings - Fork 3.9k
/
amp-a4a.js
1636 lines (1535 loc) · 60.9 KB
/
amp-a4a.js
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
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
/**
* Copyright 2016 The AMP HTML Authors. All Rights Reserved.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS-IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
import {
verifyHashVersion,
LegacySignatureVerifier,
PublicKeyInfoDef,
} from './legacy-signature-verifier';
import {
is3pThrottled,
getAmpAdRenderOutsideViewport,
incrementLoadingAds,
} from '../../amp-ad/0.1/concurrent-load';
import {signingServerURLs} from '../../../ads/_a4a-config';
import {createElementWithAttributes} from '../../../src/dom';
import {cancellation, isCancellation} from '../../../src/error';
import {
installAnchorClickInterceptor,
} from '../../../src/anchor-click-interceptor';
import {
installFriendlyIframeEmbed,
setFriendlyIframeEmbedVisible,
} from '../../../src/friendly-iframe-embed';
import {isLayoutSizeDefined} from '../../../src/layout';
import {isAdPositionAllowed} from '../../../src/ad-helper';
import {dev, user, duplicateErrorIfNecessary} from '../../../src/log';
import {dict} from '../../../src/utils/object';
import {getMode} from '../../../src/mode';
import {isArray, isObject, isEnumValue} from '../../../src/types';
import {some} from '../../../src/utils/promise';
import {utf8Decode} from '../../../src/utils/bytes';
import {viewerForDoc} from '../../../src/services';
import {xhrFor} from '../../../src/services';
import {endsWith} from '../../../src/string';
import {platformFor} from '../../../src/services';
import {isExperimentOn} from '../../../src/experiments';
import {setStyle} from '../../../src/style';
import {assertHttpsUrl} from '../../../src/url';
import {parseJson} from '../../../src/json';
import {handleClick} from '../../../ads/alp/handler';
import {
getDefaultBootstrapBaseUrl,
generateSentinel,
} from '../../../src/3p-frame';
import {
installUrlReplacementsForEmbed,
} from '../../../src/service/url-replacements-impl';
import {extensionsFor} from '../../../src/services';
import {A4AVariableSource} from './a4a-variable-source';
// TODO(tdrl): Temporary. Remove when we migrate to using amp-analytics.
import {getTimingDataAsync} from '../../../src/service/variable-source';
import {getContextMetadata} from '../../../src/iframe-attributes';
import {isInExperiment} from '../../../ads/google/a4a/traffic-experiments';
/** @type {string} */
const METADATA_STRING = '<script type="application/json" amp-ad-metadata>';
/** @type {string} */
const METADATA_STRING_NO_QUOTES =
'<script type=application/json amp-ad-metadata>';
// TODO(tdrl): Temporary, while we're verifying whether SafeFrame is an
// acceptable solution to the 'Safari on iOS doesn't fetch iframe src from
// cache' issue. See https://github.com/ampproject/amphtml/issues/5614
/** @type {string} */
export const DEFAULT_SAFEFRAME_VERSION = '1-0-9';
/** @const {string} */
const CREATIVE_SIZE_HEADER = 'X-CreativeSize';
/** @type {string} @visibleForTesting */
export const RENDERING_TYPE_HEADER = 'X-AmpAdRender';
/** @type {string} @visibleForTesting */
export const SAFEFRAME_VERSION_HEADER = 'X-AmpSafeFrameVersion';
/** @type {string} */
const TAG = 'amp-a4a';
/** @type {string} */
const NO_CONTENT_RESPONSE = 'NO-CONTENT-RESPONSE';
/** @enum {string} */
export const XORIGIN_MODE = {
CLIENT_CACHE: 'client_cache',
SAFEFRAME: 'safeframe',
NAMEFRAME: 'nameframe',
};
/** @type {!Object} @private */
const SHARED_IFRAME_PROPERTIES = dict({
'frameborder': '0',
'allowfullscreen': '',
'allowtransparency': '',
'scrolling': 'no',
'marginwidth': '0',
'marginheight': '0',
});
/** @typedef {{
* creative: ArrayBuffer,
* signature: ?Uint8Array,
* }} */
export let AdResponseDef;
/** @typedef {{width: number, height: number}} */
export let SizeInfoDef;
/** @typedef {{
minifiedCreative: string,
customElementExtensions: !Array<string>,
customStylesheets: !Array<{href: string}>
}} */
let CreativeMetaDataDef;
/**
* A set of public keys for a single AMP signing service. A single service may
* return more than one key if, e.g., they're rotating keys and they serve
* the current and upcoming keys. A CryptoKeysDef stores one or more
* (promises to) keys, in the order given by the return value from the
* signing service.
*
* @typedef {{serviceName: string, keys: !Array<!Promise<!PublicKeyInfoDef>>}}
*/
let CryptoKeysDef;
/**
* The public keys for all signing services. This is an array of promises,
* one per signing service, in the order given by the array returned by
* #getSigningServiceNames(). Each entry resolves to the keys returned by
* that service, represented by a `CryptoKeysDef` object.
*
* @typedef {Array<!Promise<!CryptoKeysDef>>}
*/
let AllServicesCryptoKeysDef;
/** @private */
export const LIFECYCLE_STAGES = {
// Note: Use strings as values here, rather than numbers, so that "0" does
// not test as `false` later.
adSlotCleared: '-1',
urlBuilt: '1',
adRequestStart: '2',
adRequestEnd: '3',
extractCreativeAndSignature: '4',
adResponseValidateStart: '5',
renderFriendlyStart: '6', // TODO(dvoytenko): this signal and similar are actually "embed-create", not "render-start".
renderCrossDomainStart: '7',
renderFriendlyEnd: '8',
renderCrossDomainEnd: '9',
preAdThrottle: '10',
renderSafeFrameStart: '11',
throttled3p: '12',
adResponseValidateEnd: '13',
xDomIframeLoaded: '14',
friendlyIframeLoaded: '15',
adSlotCollapsed: '16',
adSlotUnhidden: '17',
layoutAdPromiseDelay: '18',
signatureVerifySuccess: '19',
networkError: '20',
friendlyIframeIniLoad: '21',
visHalf: '22',
visHalfIniLoad: '23',
firstVisible: '24',
visLoadAndOneSec: '25',
iniLoad: '26',
resumeCallback: '27',
visIniLoad: '29',
};
/**
* Utility function that ensures any error thrown is handled by optional
* onError handler (if none provided or handler throws, error is swallowed and
* undefined is returned).
* @param {!Function} fn to protect
* @param {T=} inThis An optional object to use as the 'this' object
* when calling the function. If not provided, undefined is bound as this
* when calling function.
* @param {function(this:T, !Error, ...*):?=} onError function given error
* and arguments provided to function call.
* @return {!Function} protected function
* @template T
* @visibleForTesting
*/
export function protectFunctionWrapper(
fn, inThis = undefined, onError = undefined) {
return (...fnArgs) => {
try {
return fn.apply(inThis, fnArgs);
} catch (err) {
if (onError) {
try {
// Ideally we could use [err, ...var_args] but linter disallows
// spread so instead using unshift :(
fnArgs.unshift(err);
return onError.apply(inThis, fnArgs);
} catch (captureErr) {
// swallow error if error handler throws.
}
}
// In the event of no optional on error function or its execution throws,
// return undefined.
return undefined;
}
};
};
export class AmpA4A extends AMP.BaseElement {
// TODO: Add more error handling throughout code.
// TODO: Handle creatives that do not fill.
/**
* @param {!Element} element
*/
constructor(element) {
super(element);
dev().assert(AMP.AmpAdUIHandler);
dev().assert(AMP.AmpAdXOriginIframeHandler);
/** @private {?Promise<?CreativeMetaDataDef>} */
this.adPromise_ = null;
/**
* @private {number} unique ID of the currently executing promise to allow
* for cancellation.
*/
this.promiseId_ = 0;
/** {?Object} */
this.config = null;
/** @private {?string} */
this.adUrl_ = null;
/** @private {?../../../src/friendly-iframe-embed.FriendlyIframeEmbed} */
this.friendlyIframeEmbed_ = null;
/** {?AMP.AmpAdUIHandler} */
this.uiHandler = null;
/** @private {?AMP.AmpAdXOriginIframeHandler} */
this.xOriginIframeHandler_ = null;
/** @const @private {!../../../src/service/vsync-impl.Vsync} */
this.vsync_ = this.getVsync();
/** @private {boolean} whether creative has been verified as AMP */
this.isVerifiedAmpCreative_ = false;
/** @private @const {!LegacySignatureVerifier} */
this.signatureVerifier_ = new LegacySignatureVerifier(this.win);
/** @private {?ArrayBuffer} */
this.creativeBody_ = null;
/**
* Initialize this with the slot width/height attributes, and override
* later with what the network implementation returns via
* extractCreativeAndSignature. Note: Either value may be 'auto' (i.e.,
* non-numeric).
*
* @private {?({width, height}|../../../src/layout-rect.LayoutRectDef)}
*/
this.creativeSize_ = {
width: this.element.getAttribute('width'),
height: this.element.getAttribute('height'),
};
/** @private {?../../../src/layout-rect.LayoutRectDef} */
this.originalSlotSize_ = null;
/**
* Note(keithwrightbos) - ensure the default here is null so that ios
* uses safeframe when response header is not specified.
* @private {?XORIGIN_MODE}
*/
this.experimentalNonAmpCreativeRenderMethod_ =
platformFor(this.win).isIos() ? XORIGIN_MODE.SAFEFRAME : null;
/**
* Gets a notion of current time, in ms. The value is not necessarily
* absolute, so should be used only for computing deltas. When available,
* the performance system will be used; otherwise Date.now() will be
* returned.
*
* @const {function():number}
* @private
*/
this.getNow_ = (this.win.performance && this.win.performance.now) ?
this.win.performance.now.bind(this.win.performance) : Date.now;
/**
* Protected version of emitLifecycleEvent that ensures error does not
* cause promise chain to reject.
* @private {function(string, !Object=)}
*/
this.protectedEmitLifecycleEvent_ = protectFunctionWrapper(
this.emitLifecycleEvent, this,
(err, varArgs) => {
dev().error(TAG, this.element.getAttribute('type'),
'Error on emitLifecycleEvent', err, varArgs) ;
});
/** @const {string} */
this.sentinel = generateSentinel(window);
/**
* Used to indicate whether this slot should be collapsed or not. Marked
* true if the ad response has status 204, is null, or has a null
* arrayBuffer.
* @private {boolean}
*/
this.isCollapsed_ = false;
/**
* Frame in which the creative renders (friendly if validated AMP, xdomain
* otherwise).
* {?HTMLIframeElement}
*/
this.iframe = null;
/**
* TODO(keithwrightbos) - remove once resume behavior is verified.
* {boolean} whether most recent ad request was generated as part
* of resume callback.
*/
this.fromResumeCallback = false;
const type = (this.element.getAttribute('type') || 'notype').toLowerCase();
/**
* @private @const{boolean} whether request should only be sent when slot is
* within renderOutsideViewport distance.
*/
this.delayRequestEnabled_ =
(type == 'adsense' && isInExperiment(this.element, '117152655')) ||
(type == 'doubleclick' && isInExperiment(this.element, '117152665'));
/** @private {string} */
this.safeframeVersion_ = DEFAULT_SAFEFRAME_VERSION;
}
/** @override */
getPriority() {
// Priority used for scheduling preload and layout callback. Because
// AMP creatives will be injected as part of the promise chain created
// within onLayoutMeasure, this is only relevant to non-AMP creatives
// therefore we want this to match the 3p priority.
return 2;
}
/** @override */
isLayoutSupported(layout) {
return isLayoutSizeDefined(layout);
}
/** @override */
buildCallback() {
this.uiHandler = new AMP.AmpAdUIHandler(this);
if (!this.win.ampA4aValidationKeys) {
// Without the following variable assignment, there's no way to apply a
// type annotation to a win-scoped variable, so the type checker doesn't
// catch type errors here. This no-op allows us to enforce some type
// expectations. The const assignment will hopefully be optimized
// away by the compiler. *fingers crossed*
/** @type {!AllServicesCryptoKeysDef} */
const forTypeSafety = this.getKeyInfoSets_();
this.win.ampA4aValidationKeys = forTypeSafety;
}
}
/** @override */
renderOutsideViewport() {
// Ensure non-verified AMP creatives are throttled.
if (!this.isVerifiedAmpCreative_ && is3pThrottled(this.win)) {
this.protectedEmitLifecycleEvent_('throttled3p');
return false;
}
// Otherwise the ad is good to go.
const elementCheck = getAmpAdRenderOutsideViewport(this.element);
return elementCheck !== null ?
elementCheck : super.renderOutsideViewport();
}
/**
* To be overridden by network specific implementation indicating if element
* (and environment generally) are valid for sending XHR queries.
* @return {boolean} whether element is valid and ad request should be
* sent. If false, no ad request is sent and slot will be collapsed if
* possible.
*/
isValidElement() {
return true;
}
/**
* Returns preconnect urls for A4A. Ad network should overwrite in their
* Fast Fetch implementation and return an array of urls for the runtime to
* preconnect to.
* @return {!Array<string>}
*/
getPreconnectUrls() {
return [];
}
/**
* Returns prefetch urls for A4A. Ad network should overwrite in their
* Fast Fetch implementation and return an array of urls for the runtime to
* prefetch.
* @return {!Array<string>}
*/
getPrefetchUrls() {
return [];
}
/**
* Returns true if this element was loaded from an amp-ad element. For use by
* network-specific implementations that don't want to allow themselves to be
* embedded directly into a page.
* @return {boolean}
*/
isAmpAdElement() {
return this.element.tagName == 'AMP-AD' ||
this.element.tagName == 'AMP-EMBED';
}
/**
* Prefetches and preconnects URLs related to the ad using adPreconnect
* registration which assumes ad request domain used for 3p is applicable.
* @param {boolean=} unusedOnLayout
* @override
*/
preconnectCallback(unusedOnLayout) {
this.preconnect.preload(this.getSafeframePath_());
this.preconnect.preload(getDefaultBootstrapBaseUrl(this.win, 'nameframe'));
const preconnect = this.getPreconnectUrls();
// NOTE(keithwrightbos): using onLayout to indicate if preconnect should be
// given preferential treatment. Currently this would be false when
// relevant (i.e. want to preconnect on or before onLayoutMeasure) which
// causes preconnect to delay for 1 sec (see custom-element#preconnect)
// therefore hard coding to true.
// NOTE(keithwrightbos): Does not take isValidElement into account so could
// preconnect unnecessarily, however it is assumed that isValidElement
// matches amp-ad loader predicate such that A4A impl does not load.
if (preconnect) {
preconnect.forEach(p => {
this.preconnect.url(p, true);
});
}
}
/** @override */
resumeCallback() {
// FIE that was not destroyed on unlayoutCallback does not require a new
// ad request.
if (this.friendlyIframeEmbed_) {
return;
}
this.protectedEmitLifecycleEvent_('resumeCallback');
this.fromResumeCallback = true;
// If layout of page has not changed, onLayoutMeasure will not be called
// so do so explicitly.
const resource = this.getResource();
if (resource.hasBeenMeasured() && !resource.isMeasureRequested()) {
this.onLayoutMeasure();
}
}
/**
* @return {!../../../src/service/resource.Resource}
* @visibileForTesting
*/
getResource() {
return this.element.getResources().getResourceForElement(this.element);
}
/**
* @return {boolean} whether adPromise was initialized (indicator of
* element validity).
* @protected
*/
hasAdPromise() {
return !!this.adPromise_;
}
/**
* @return {boolean} whether environment/element should initialize ad request
* promise chain.
* @private
*/
shouldInitializePromiseChain_() {
if (!this.signatureVerifier_.isAvailable()) {
return false;
}
const slotRect = this.getIntersectionElementLayoutBox();
if (slotRect.height == 0 || slotRect.width == 0) {
dev().fine(
TAG, 'onLayoutMeasure canceled due height/width 0', this.element);
return false;
}
if (!isAdPositionAllowed(this.element, this.win)) {
user().warn(TAG, `<${this.element.tagName}> is not allowed to be ` +
`placed in elements with position:fixed: ${this.element}`);
return false;
}
// OnLayoutMeasure can be called when page is in prerender so delay until
// visible. Assume that it is ok to call isValidElement as it should
// only being looking at window, immutable properties (i.e. location) and
// its element ancestry.
if (!this.isValidElement()) {
// TODO(kjwright): collapse?
user().warn(TAG, this.element.getAttribute('type'),
'Amp ad element ignored as invalid', this.element);
return false;
}
return true;
}
/** @override */
onLayoutMeasure() {
if (this.xOriginIframeHandler_) {
this.xOriginIframeHandler_.onLayoutMeasure();
}
if (this.adPromise_ || !this.shouldInitializePromiseChain_()) {
return;
}
// If in localDev `type=fake` Ad specifies `force3p`, it will be forced
// to go via 3p.
if (getMode().localDev &&
this.element.getAttribute('type') == 'fake' &&
this.element.getAttribute('force3p') == 'true') {
this.adUrl_ = this.getAdUrl();
this.adPromise_ = Promise.resolve();
return;
}
// Increment unique promise ID so that if its value changes within the
// promise chain due to cancel from unlayout, the promise will be rejected.
++this.promiseId_;
// Shorthand for: reject promise if current promise chain is out of date.
const checkStillCurrent = this.verifyStillCurrent();
// Return value from this chain: True iff rendering was "successful"
// (i.e., shouldn't try to render later via iframe); false iff should
// try to render later in iframe.
// Cases to handle in this chain:
// - Everything ok => Render; return true
// - Empty network response returned => Don't render; return true
// - Can't parse creative out of response => Don't render; return false
// - Can parse, but creative is empty => Don't render; return true
// - Validation fails => return false
// - Rendering fails => return false
// - Chain cancelled => don't return; drop error
// - Uncaught error otherwise => don't return; percolate error up
this.adPromise_ = viewerForDoc(this.getAmpDoc()).whenFirstVisible()
.then(() => {
checkStillCurrent();
// See if experiment that delays request until slot is within
// renderOutsideViewport. Within render outside viewport will not
// resolve if already within viewport thus the check for already
// meeting the definition as opposed to waiting on the promise.
if (this.delayRequestEnabled_ &&
!this.getResource().renderOutsideViewport()) {
return this.getResource().whenWithinRenderOutsideViewport();
}
})
// This block returns the ad URL, if one is available.
/** @return {!Promise<?string>} */
.then(() => {
checkStillCurrent();
if (this.delayRequestEnabled_) {
dev().info(TAG, 'ad request being built');
}
return /** @type {!Promise<?string>} */ (this.getAdUrl());
})
// This block returns the (possibly empty) response to the XHR request.
/** @return {!Promise<?Response>} */
.then(adUrl => {
checkStillCurrent();
this.adUrl_ = adUrl;
this.protectedEmitLifecycleEvent_('urlBuilt');
return adUrl && this.sendXhrRequest(adUrl);
})
// The following block returns either the response (as a {bytes, headers}
// object), or null if no response is available / response is empty.
/** @return {?Promise<?{bytes: !ArrayBuffer, headers: !Headers}>} */
.then(fetchResponse => {
checkStillCurrent();
this.protectedEmitLifecycleEvent_('adRequestEnd');
// If the response is null, we want to return null so that
// unlayoutCallback will attempt to render via x-domain iframe,
// assuming ad url or creative exist.
if (!fetchResponse) {
return null;
}
// If the response has response code 204, or arrayBuffer is null,
// collapse it.
if (!fetchResponse.arrayBuffer || fetchResponse.status == 204) {
this.forceCollapse();
return Promise.reject(NO_CONTENT_RESPONSE);
}
// TODO(tdrl): Temporary, while we're verifying whether SafeFrame is
// an acceptable solution to the 'Safari on iOS doesn't fetch
// iframe src from cache' issue. See
// https://github.com/ampproject/amphtml/issues/5614
const method = fetchResponse.headers.get(RENDERING_TYPE_HEADER) ||
this.experimentalNonAmpCreativeRenderMethod_;
this.experimentalNonAmpCreativeRenderMethod_ = method;
if (method && !isEnumValue(XORIGIN_MODE, method)) {
dev().error('AMP-A4A', `cross-origin render mode header ${method}`);
}
const safeframeVersionHeader =
fetchResponse.headers.get(SAFEFRAME_VERSION_HEADER);
if (/^[0-9-]+$/.test(safeframeVersionHeader) &&
safeframeVersionHeader != DEFAULT_SAFEFRAME_VERSION) {
this.safeframeVersion_ = safeframeVersionHeader;
this.preconnect.preload(this.getSafeframePath_());
}
// Note: Resolving a .then inside a .then because we need to capture
// two fields of fetchResponse, one of which is, itself, a promise,
// and one of which isn't. If we just return
// fetchResponse.arrayBuffer(), the next step in the chain will
// resolve it to a concrete value, but we'll lose track of
// fetchResponse.headers.
return fetchResponse.arrayBuffer().then(bytes => {
if (bytes.byteLength == 0) {
// The server returned no content. Instead of displaying a blank
// rectangle, we collapse the slot instead.
this.forceCollapse();
return Promise.reject(NO_CONTENT_RESPONSE);
}
return {
bytes,
headers: fetchResponse.headers,
};
});
})
// This block returns the ad creative, signature, and size, if
// available; null otherwise.
/**
* @return {?Promise<{creativeParts: !AdResponseDef, size: ?SizeInfoDef}>}
*/
.then(responseParts => {
checkStillCurrent();
if (!responseParts) {
return null;
}
this.protectedEmitLifecycleEvent_('extractCreativeAndSignature');
const size = this.extractSize(responseParts.headers);
return this.extractCreativeAndSignature(
responseParts.bytes, responseParts.headers)
.then(creativeParts => ({creativeParts, size}));
})
// This block returns the ad creative if it exists and validates as AMP;
// null otherwise.
/** @return {!Promise<?ArrayBuffer>} */
.then(creativeData => {
checkStillCurrent();
// Keep a handle to the creative body so that we can render into
// SafeFrame or NameFrame later, if necessary. TODO(tdrl): Temporary,
// while we
// assess whether this is the right solution to the Safari+iOS iframe
// src cache issue. If we decide to keep a SafeFrame-like solution,
// we should restructure the promise chain to pass this info along
// more cleanly, without use of an object variable outside the chain.
if (!creativeData) {
return Promise.resolve();
}
const {creativeParts, size} = creativeData;
this.creativeSize_ = size || this.creativeSize_;
if (this.experimentalNonAmpCreativeRenderMethod_ !=
XORIGIN_MODE.CLIENT_CACHE &&
creativeParts.creative) {
this.creativeBody_ = creativeParts.creative;
}
if (!creativeParts.signature) {
return Promise.resolve();
}
this.protectedEmitLifecycleEvent_('adResponseValidateStart');
return this.verifyCreativeSignature_(
creativeParts.creative, creativeParts.signature)
.then(creative => {
if (creative) {
return creative;
}
user().error(TAG, this.element.getAttribute('type'),
'Unable to validate AMP creative against key providers');
// Attempt to re-fetch the keys in case our locally cached
// batch has expired.
this.win.ampA4aValidationKeys = this.getKeyInfoSets_();
return this.verifyCreativeSignature_(
creativeParts.creative, creativeParts.signature);
});
})
.then(creative => {
checkStillCurrent();
// Need to know if creative was verified as part of render outside
// viewport but cannot wait on promise. Sadly, need a state a
// variable.
this.isVerifiedAmpCreative_ = !!creative;
// TODO(levitzky) If creative comes back null, we should consider re-
// fetching the signing server public keys and try the verification
// step again.
return creative && utf8Decode(creative);
})
// This block returns CreativeMetaDataDef iff the creative was verified
// as AMP and could be properly parsed for friendly iframe render.
/** @return {?CreativeMetaDataDef} */
.then(creativeDecoded => {
checkStillCurrent();
// Note: It's critical that #getAmpAdMetadata_ be called
// on precisely the same creative that was validated
// via #validateAdResponse_. See GitHub issue
// https://github.com/ampproject/amphtml/issues/4187
let creativeMetaDataDef;
if (!creativeDecoded ||
!(creativeMetaDataDef = this.getAmpAdMetadata_(creativeDecoded))) {
return null;
}
// Update priority.
this.updatePriority(0);
// Load any extensions; do not wait on their promises as this
// is just to prefetch.
const extensions = extensionsFor(this.win);
creativeMetaDataDef.customElementExtensions.forEach(
extensionId => extensions.loadExtension(extensionId));
return creativeMetaDataDef;
})
.catch(error => {
if (error == NO_CONTENT_RESPONSE) {
return {
minifiedCreative: '',
customElementExtensions: [],
customStylesheets: [],
};
}
// If error in chain occurs, report it and return null so that
// layoutCallback can render via cross domain iframe assuming ad
// url or creative exist.
this.promiseErrorHandler_(error);
return null;
});
}
/**
* Attempts to validate the creative signature against every key currently in
* our possession. This should never be called before at least one key fetch
* attempt is made.
*
* @param {!ArrayBuffer} creative
* @param {!Uint8Array} signature
* @return {!Promise<!ArrayBuffer>} The creative.
*/
verifyCreativeSignature_(creative, signature) {
if (getMode().localDev) {
// localDev mode allows "FAKESIG" signature for the "fake" network.
if (signature == 'FAKESIG' &&
this.element.getAttribute('type') == 'fake') {
return Promise.resolve(creative);
}
}
// For each signing service, we have exactly one Promise,
// keyInfoSetPromise, that holds an Array of Promises of signing keys.
// So long as any one of these signing services can verify the
// signature, then the creative is valid AMP.
/** @type {!AllServicesCryptoKeysDef} */
const keyInfoSetPromises = this.win.ampA4aValidationKeys;
// Track if verification found, as it will ensure that promises yet to
// resolve will "cancel" as soon as possible saving unnecessary resource
// allocation.
let verified = false;
return some(keyInfoSetPromises.map(keyInfoSetPromise => {
// Resolve Promise into an object containing a 'keys' field, which
// is an Array of Promises of signing keys. *whew*
return keyInfoSetPromise.then(keyInfoSet => {
// As long as any one individual key of a particular signing
// service, keyInfoPromise, can verify the signature, then the
// creative is valid AMP.
if (verified) {
return Promise.reject('noop');
}
return some(keyInfoSet.keys.map(keyInfoPromise => {
// Resolve Promise into signing key.
return keyInfoPromise.then(keyInfo => {
if (verified) {
return Promise.reject('noop');
}
if (!keyInfo) {
return Promise.reject('Promise resolved to null key.');
}
const signatureVerifyStartTime = this.getNow_();
// If the key exists, try verifying with it.
return this.signatureVerifier_.verifySignature(
new Uint8Array(creative),
signature,
keyInfo)
.then(isValid => {
if (isValid) {
verified = true;
this.protectedEmitLifecycleEvent_(
'signatureVerifySuccess', {
'met.delta.AD_SLOT_ID': Math.round(
this.getNow_() - signatureVerifyStartTime),
'signingServiceName.AD_SLOT_ID': keyInfo.serviceName,
});
return creative;
}
// Only report if signature is expected to match, given that
// multiple key providers could have been specified.
// Note: the 'keyInfo &&' check here is not strictly
// necessary, because we checked that above. But
// Closure type compiler can't seem to recognize that, so
// this guarantees it to the compiler.
if (keyInfo && verifyHashVersion(signature, keyInfo)) {
user().error(TAG, this.element.getAttribute('type'),
'Key failed to validate creative\'s signature',
keyInfo.serviceName, keyInfo.cryptoKey);
}
// Reject to ensure the some operation waits for other
// possible providers to properly verify and resolve.
return Promise.reject(
`${keyInfo.serviceName} key failed to verify`);
},
err => {
dev().error(
TAG, this.element.getAttribute('type'),
keyInfo.serviceName, err, this.element);
});
});
}))
// some() returns an array of which we only need a single value.
.then(returnedArray => returnedArray[0], () => {
// Rejection occurs if all keys for this provider fail to validate.
return Promise.reject(
`All keys for ${keyInfoSet.serviceName} failed to verify`);
});
});
}))
.then(returnedArray => {
this.protectedEmitLifecycleEvent_('adResponseValidateEnd');
return returnedArray[0];
}, () => {
// rejection occurs if all providers fail to verify.
this.protectedEmitLifecycleEvent_('adResponseValidateEnd');
return Promise.reject('No validation service could verify this key');
});
}
/**
* Handles uncaught errors within promise flow.
* @param {*} error
* @param {boolean=} opt_ignoreStack
* @private
*/
promiseErrorHandler_(error, opt_ignoreStack) {
if (isCancellation(error)) {
// Rethrow if cancellation.
throw error;
}
if (error && error.message) {
error = duplicateErrorIfNecessary(/** @type {!Error} */(error));
} else {
error = new Error('unknown error ' + error);
}
if (opt_ignoreStack) {
error.ignoreStack = opt_ignoreStack;
}
// Add `type` to the message. Ensure to preserve the original stack.
const type = this.element.getAttribute('type') || 'notype';
if (error.message.indexOf(`${TAG}: ${type}:`) != 0) {
error.message = `${TAG}: ${type}: ${error.message}`;
}
// Additional arguments.
assignAdUrlToError(/** @type {!Error} */(error), this.adUrl_);
if (getMode().development || getMode().localDev || getMode().log) {
user().error(TAG, error);
} else {
user().warn(TAG, error);
// Report with 1% sampling as an expected dev error.
if (Math.random() < 0.01) {
dev().expectedError(TAG, error);
}
}
}
/** @override */
layoutCallback() {
// Promise may be null if element was determined to be invalid for A4A.
if (!this.adPromise_) {
if (this.shouldInitializePromiseChain_()) {
dev().error(TAG, 'Null promise in layoutCallback');
}
return Promise.resolve();
}
// There's no real throttling with A4A, but this is the signal that is
// most comparable with the layout callback for 3p ads.
this.protectedEmitLifecycleEvent_('preAdThrottle');
const layoutCallbackStart = this.getNow_();
const checkStillCurrent = this.verifyStillCurrent();
// Promise chain will have determined if creative is valid AMP.
return this.adPromise_.then(creativeMetaData => {
checkStillCurrent();
const delta = this.getNow_() - layoutCallbackStart;
this.protectedEmitLifecycleEvent_('layoutAdPromiseDelay', {
layoutAdPromiseDelay: Math.round(delta),
isAmpCreative: !!creativeMetaData,
});
if (this.isCollapsed_) {
return Promise.resolve();
}
// If this.iframe already exists, bail out here. This should only happen in
// testing context, not in production.
if (this.iframe) {
this.protectedEmitLifecycleEvent_('iframeAlreadyExists');
return Promise.resolve();
}
if (!creativeMetaData) {
// Non-AMP creative case, will verify ad url existence.
return this.renderNonAmpCreative_();
}
// Must be an AMP creative.
return this.renderAmpCreative_(creativeMetaData)
.catch(err => {
checkStillCurrent();
// Failed to render via AMP creative path so fallback to non-AMP
// rendering within cross domain iframe.
user().error(TAG, this.element.getAttribute('type'),
'Error injecting creative in friendly frame', err);
this.promiseErrorHandler_(err);
return this.renderNonAmpCreative_();
});
}).catch(error => {
this.promiseErrorHandler_(error);
throw cancellation();
});
}
/** @override **/
attemptChangeSize(newHeight, newWidth) {
// Store original size of slot in order to allow re-expansion on
// unlayoutCallback so that it is reverted to original size in case
// of resumeCallback.
this.originalSlotSize_ = this.originalSlotSize_ || this.getLayoutBox();
return super.attemptChangeSize(newHeight, newWidth).catch(() => {});
}
/** @override */
unlayoutCallback() {
if (this.friendlyIframeEmbed_) {
return false;
}
// Increment promiseId to cause any pending promise to cancel.
this.promiseId_++;
this.protectedEmitLifecycleEvent_('adSlotCleared');
this.uiHandler.applyUnlayoutUI();
if (this.originalSlotSize_) {
super.attemptChangeSize(
this.originalSlotSize_.height, this.originalSlotSize_.width)
.then(() => {
this.originalSlotSize_ = null;
})
.catch(err => {
// TODO(keithwrightbos): if we are unable to revert size, on next
// trigger of promise chain the ad request may fail due to invalid
// slot size. Determine how to handle this case.
dev().warn(TAG, 'unable to revert to original size', err);
});
}
this.isCollapsed_ = false;
// Allow embed to release its resources.
if (this.friendlyIframeEmbed_) {
this.friendlyIframeEmbed_.destroy();
this.friendlyIframeEmbed_ = null;
}
// Remove rendering frame, if it exists.