summaryrefslogtreecommitdiffstats
path: root/toolkit/content/aboutNetError.mjs
blob: b458a8ccab23facfb3bf7f92d87675a792442658 (plain)
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
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
1040
1041
1042
1043
1044
1045
1046
1047
1048
1049
1050
1051
1052
1053
1054
1055
1056
1057
1058
1059
1060
1061
1062
1063
1064
1065
1066
1067
1068
1069
1070
1071
1072
1073
1074
1075
1076
1077
1078
1079
1080
1081
1082
1083
1084
1085
1086
1087
1088
1089
1090
1091
1092
1093
1094
1095
1096
1097
1098
1099
1100
1101
1102
1103
1104
1105
1106
1107
1108
1109
1110
1111
1112
1113
1114
1115
1116
1117
1118
1119
1120
1121
1122
1123
1124
1125
1126
1127
1128
1129
1130
1131
1132
1133
1134
1135
1136
1137
1138
1139
1140
1141
1142
1143
1144
1145
1146
1147
1148
1149
1150
1151
1152
1153
1154
1155
1156
1157
1158
1159
1160
1161
1162
1163
1164
1165
1166
1167
1168
1169
1170
1171
1172
1173
1174
1175
1176
1177
1178
1179
1180
1181
1182
1183
1184
1185
1186
1187
1188
1189
1190
1191
1192
1193
1194
1195
1196
1197
1198
1199
1200
1201
1202
1203
1204
1205
1206
1207
1208
1209
1210
1211
1212
1213
1214
1215
1216
1217
1218
1219
1220
1221
1222
1223
1224
1225
1226
1227
1228
1229
1230
1231
1232
1233
1234
1235
1236
1237
1238
1239
1240
1241
1242
1243
1244
1245
1246
1247
1248
1249
1250
1251
1252
1253
1254
1255
1256
1257
1258
1259
1260
1261
1262
1263
1264
1265
1266
1267
1268
1269
1270
1271
1272
1273
1274
1275
1276
1277
1278
1279
1280
1281
1282
1283
1284
1285
1286
1287
1288
1289
1290
1291
1292
1293
1294
1295
1296
1297
1298
1299
1300
1301
1302
1303
1304
1305
1306
1307
1308
1309
1310
1311
1312
1313
1314
1315
1316
1317
1318
1319
1320
1321
1322
1323
1324
1325
1326
1327
1328
1329
1330
1331
1332
1333
1334
1335
1336
1337
1338
1339
1340
1341
1342
1343
1344
1345
1346
1347
1348
1349
1350
1351
1352
1353
1354
1355
1356
1357
1358
1359
1360
1361
1362
1363
1364
1365
1366
1367
1368
1369
1370
1371
1372
1373
1374
1375
1376
1377
1378
1379
1380
1381
1382
1383
1384
1385
1386
1387
1388
1389
1390
1391
1392
1393
1394
1395
1396
1397
1398
1399
1400
1401
1402
1403
1404
1405
1406
1407
1408
1409
1410
1411
1412
1413
1414
1415
1416
1417
1418
1419
1420
1421
1422
1423
1424
1425
1426
1427
1428
1429
1430
1431
1432
1433
1434
1435
1436
1437
1438
1439
1440
1441
1442
1443
1444
1445
1446
1447
1448
1449
1450
1451
1452
1453
1454
1455
1456
1457
1458
1459
1460
1461
1462
1463
1464
1465
1466
1467
1468
1469
1470
1471
1472
1473
1474
1475
1476
1477
1478
1479
1480
1481
1482
1483
1484
1485
1486
1487
1488
1489
1490
1491
1492
1493
1494
1495
1496
1497
1498
1499
1500
1501
1502
1503
1504
1505
1506
1507
1508
1509
1510
1511
1512
1513
1514
1515
1516
1517
1518
1519
1520
1521
1522
1523
1524
1525
1526
1527
1528
1529
1530
1531
1532
1533
1534
1535
1536
1537
1538
1539
1540
1541
1542
1543
1544
1545
1546
1547
1548
1549
1550
1551
1552
1553
1554
1555
1556
/* 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/. */

/* eslint-env mozilla/remote-page */
/* eslint-disable import/no-unassigned-import */

import {
  parse,
  pemToDER,
} from "chrome://global/content/certviewer/certDecoder.mjs";

const formatter = new Intl.DateTimeFormat();

const HOST_NAME = getHostName();

function getHostName() {
  try {
    return new URL(RPMGetInnerMostURI(document.location.href)).hostname;
  } catch (error) {
    console.error("Could not parse URL", error);
  }
  return "";
}

// Used to check if we have a specific localized message for an error.
const KNOWN_ERROR_TITLE_IDS = new Set([
  // Error titles:
  "connectionFailure-title",
  "deniedPortAccess-title",
  "dnsNotFound-title",
  "dns-not-found-trr-only-title2",
  "fileNotFound-title",
  "fileAccessDenied-title",
  "generic-title",
  "captivePortal-title",
  "malformedURI-title",
  "netInterrupt-title",
  "notCached-title",
  "netOffline-title",
  "contentEncodingError-title",
  "unsafeContentType-title",
  "netReset-title",
  "netTimeout-title",
  "unknownProtocolFound-title",
  "proxyConnectFailure-title",
  "proxyResolveFailure-title",
  "redirectLoop-title",
  "unknownSocketType-title",
  "nssFailure2-title",
  "csp-xfo-error-title",
  "corruptedContentError-title",
  "sslv3Used-title",
  "inadequateSecurityError-title",
  "blockedByPolicy-title",
  "clockSkewError-title",
  "networkProtocolError-title",
  "nssBadCert-title",
  "nssBadCert-sts-title",
  "certerror-mitm-title",
]);

/* The error message IDs from nsserror.ftl get processed into
 * aboutNetErrorCodes.js which is loaded before we are: */
/* global KNOWN_ERROR_MESSAGE_IDS */
const ERROR_MESSAGES_FTL = "toolkit/neterror/nsserrors.ftl";

// The following parameters are parsed from the error URL:
//   e - the error code
//   s - custom CSS class to allow alternate styling/favicons
//   d - error description
//   captive - "true" to indicate we're behind a captive portal.
//             Any other value is ignored.

// Note that this file uses document.documentURI to get
// the URL (with the format from above). This is because
// document.location.href gets the current URI off the docshell,
// which is the URL displayed in the location bar, i.e.
// the URI that the user attempted to load.

let searchParams = new URLSearchParams(document.documentURI.split("?")[1]);

let gErrorCode = searchParams.get("e");
let gIsCertError = gErrorCode == "nssBadCert";
let gHasSts = gIsCertError && getCSSClass() === "badStsCert";

// If the location of the favicon changes, FAVICON_CERTERRORPAGE_URL and/or
// FAVICON_ERRORPAGE_URL in toolkit/components/places/nsFaviconService.idl
// should also be updated.
document.getElementById("favicon").href =
  gIsCertError || gErrorCode == "nssFailure2"
    ? "chrome://global/skin/icons/warning.svg"
    : "chrome://global/skin/icons/info.svg";

function getCSSClass() {
  return searchParams.get("s");
}

function getDescription() {
  return searchParams.get("d");
}

function isCaptive() {
  return searchParams.get("captive") == "true";
}

/**
 * We don't actually know what the MitM is called (since we don't
 * maintain a list), so we'll try and display the common name of the
 * root issuer to the user. In the worst case they are as clueless as
 * before, in the best case this gives them an actionable hint.
 * This may be revised in the future.
 */
function getMitmName(failedCertInfo) {
  return failedCertInfo.issuerCommonName;
}

function retryThis(buttonEl) {
  RPMSendAsyncMessage("Browser:EnableOnlineMode");
  buttonEl.disabled = true;
}

function showPrefChangeContainer() {
  const panel = document.getElementById("prefChangeContainer");
  panel.hidden = false;
  document.getElementById("netErrorButtonContainer").hidden = true;
  document
    .getElementById("prefResetButton")
    .addEventListener("click", function resetPreferences() {
      RPMSendAsyncMessage("Browser:ResetSSLPreferences");
    });
  setFocus("#prefResetButton", "beforeend");
}

function toggleCertErrorDebugInfoVisibility(shouldShow) {
  let debugInfo = document.getElementById("certificateErrorDebugInformation");
  let copyButton = document.getElementById("copyToClipboardTop");

  if (shouldShow === undefined) {
    shouldShow = debugInfo.hidden;
  }
  debugInfo.hidden = !shouldShow;
  if (shouldShow) {
    copyButton.scrollIntoView({ block: "start", behavior: "smooth" });
    copyButton.focus();
  }
}

function setupAdvancedButton() {
  // Get the hostname and add it to the panel
  var panel = document.getElementById("badCertAdvancedPanel");

  // Register click handler for the weakCryptoAdvancedPanel
  document
    .getElementById("advancedButton")
    .addEventListener("click", togglePanelVisibility);

  function togglePanelVisibility() {
    if (panel.hidden) {
      // Reveal
      revealAdvancedPanelSlowlyAsync();

      // send event to trigger telemetry ping
      document.dispatchEvent(
        new CustomEvent("AboutNetErrorUIExpanded", { bubbles: true })
      );
    } else {
      // Hide
      panel.hidden = true;
    }
  }

  if (getCSSClass() == "expertBadCert") {
    revealAdvancedPanelSlowlyAsync();
  }
}

async function revealAdvancedPanelSlowlyAsync() {
  const badCertAdvancedPanel = document.getElementById("badCertAdvancedPanel");
  const exceptionDialogButton = document.getElementById(
    "exceptionDialogButton"
  );

  // Toggling the advanced panel must ensure that the debugging
  // information panel is hidden as well, since it's opened by the
  // error code link in the advanced panel.
  toggleCertErrorDebugInfoVisibility(false);

  // Reveal, but disabled (and grayed-out) for 3.0s.
  badCertAdvancedPanel.hidden = false;
  exceptionDialogButton.disabled = true;

  // -

  if (exceptionDialogButton.resetReveal) {
    exceptionDialogButton.resetReveal(); // Reset if previous is pending.
  }
  let wasReset = false;
  exceptionDialogButton.resetReveal = () => {
    wasReset = true;
  };

  // Wait for 10 frames to ensure that the warning text is rendered
  // and gets all the way to the screen for the user to read it.
  // This is only ~0.160s at 60Hz, so it's not too much extra time that we're
  // taking to ensure that we're caught up with rendering, on top of the
  // (by default) whole second(s) we're going to wait based on the
  // security.dialog_enable_delay pref.
  // The catching-up to rendering is the important part, not the
  // N-frame-delay here.
  for (let i = 0; i < 10; i++) {
    await new Promise(requestAnimationFrame);
  }

  // Wait another Nms (default: 1000) for the user to be very sure. (Sorry speed readers!)
  const securityDelayMs = RPMGetIntPref("security.dialog_enable_delay", 1000);
  await new Promise(go => setTimeout(go, securityDelayMs));

  if (wasReset) {
    return;
  }

  // Enable and un-gray-out.
  exceptionDialogButton.disabled = false;
}

function disallowCertOverridesIfNeeded() {
  // Disallow overrides if this is a Strict-Transport-Security
  // host and the cert is bad (STS Spec section 7.3) or if the
  // certerror is in a frame (bug 633691).
  if (gHasSts || window != top) {
    document.getElementById("exceptionDialogButton").hidden = true;
  }
  if (gHasSts) {
    const stsExplanation = document.getElementById("badStsCertExplanation");
    document.l10n.setAttributes(
      stsExplanation,
      "certerror-what-should-i-do-bad-sts-cert-explanation",
      { hostname: HOST_NAME }
    );
    stsExplanation.hidden = false;

    document.l10n.setAttributes(
      document.getElementById("returnButton"),
      "neterror-return-to-previous-page-button"
    );
    document.l10n.setAttributes(
      document.getElementById("advancedPanelReturnButton"),
      "neterror-return-to-previous-page-button"
    );
  }
}

function recordTRREventTelemetry(
  warningPageType,
  trrMode,
  trrDomain,
  skipReason
) {
  RPMRecordTelemetryEvent(
    "security.doh.neterror",
    "load",
    "dohwarning",
    warningPageType,
    {
      mode: trrMode,
      provider_key: trrDomain,
      skip_reason: skipReason,
    }
  );

  const netErrorButtonDiv = document.getElementById("netErrorButtonContainer");
  const buttons = netErrorButtonDiv.querySelectorAll("button");
  for (let b of buttons) {
    b.addEventListener("click", function (e) {
      let target = e.originalTarget;
      let telemetryId = target.dataset.telemetryId;
      RPMRecordTelemetryEvent(
        "security.doh.neterror",
        "click",
        telemetryId,
        warningPageType,
        {
          mode: trrMode,
          provider_key: trrDomain,
          skip_reason: skipReason,
        }
      );
    });
  }
}

function initPage() {
  // We show an offline support page in case of a system-wide error,
  // when a user cannot connect to the internet and access the SUMO website.
  // For example, clock error, which causes certerrors across the web or
  // a security software conflict where the user is unable to connect
  // to the internet.
  // The URL that prompts us to show an offline support page should have the following
  // format: "https://support.mozilla.org/1/firefox/%VERSION%/%OS%/%LOCALE%/supportPageSlug",
  // so we can extract the support page slug.
  let baseURL = RPMGetFormatURLPref("app.support.baseURL");
  if (document.location.href.startsWith(baseURL)) {
    let supportPageSlug = document.location.pathname.split("/").pop();
    RPMSendAsyncMessage("DisplayOfflineSupportPage", {
      supportPageSlug,
    });
  }

  const className = getCSSClass();
  if (className) {
    document.body.classList.add(className);
  }

  const isTRROnlyFailure = gErrorCode == "dnsNotFound" && RPMIsTRROnlyFailure();

  let isNativeFallbackWarning = false;
  if (RPMGetBoolPref("network.trr.display_fallback_warning")) {
    isNativeFallbackWarning =
      gErrorCode == "dnsNotFound" && RPMIsNativeFallbackFailure();
  }

  const docTitle = document.querySelector("title");
  const bodyTitle = document.querySelector(".title-text");
  const shortDesc = document.getElementById("errorShortDesc");

  if (gIsCertError) {
    const isStsError = window !== window.top || gHasSts;
    const errArgs = { hostname: HOST_NAME };
    if (isCaptive()) {
      document.l10n.setAttributes(
        docTitle,
        "neterror-captive-portal-page-title"
      );
      document.l10n.setAttributes(bodyTitle, "captivePortal-title");
      document.l10n.setAttributes(
        shortDesc,
        "neterror-captive-portal",
        errArgs
      );
      initPageCaptivePortal();
    } else {
      if (isStsError) {
        document.l10n.setAttributes(docTitle, "certerror-sts-page-title");
        document.l10n.setAttributes(bodyTitle, "nssBadCert-sts-title");
        document.l10n.setAttributes(shortDesc, "certerror-sts-intro", errArgs);
      } else {
        document.l10n.setAttributes(docTitle, "certerror-page-title");
        document.l10n.setAttributes(bodyTitle, "nssBadCert-title");
        document.l10n.setAttributes(shortDesc, "certerror-intro", errArgs);
      }
      initPageCertError();
    }

    initCertErrorPageActions();
    setTechnicalDetailsOnCertError();
    return;
  }

  document.body.classList.add("neterror");

  let longDesc = document.getElementById("errorLongDesc");
  const tryAgain = document.getElementById("netErrorButtonContainer");
  tryAgain.hidden = false;
  const learnMore = document.getElementById("learnMoreContainer");
  const learnMoreLink = document.getElementById("learnMoreLink");
  learnMoreLink.setAttribute("href", baseURL + "connection-not-secure");

  let pageTitleId = "neterror-page-title";
  let bodyTitleId = gErrorCode + "-title";

  switch (gErrorCode) {
    case "blockedByPolicy":
      pageTitleId = "neterror-blocked-by-policy-page-title";
      document.body.classList.add("blocked");

      // Remove the "Try again" button from pages that don't need it.
      // For pages blocked by policy, trying again won't help.
      tryAgain.hidden = true;
      break;

    case "cspBlocked":
    case "xfoBlocked": {
      bodyTitleId = "csp-xfo-error-title";

      // Remove the "Try again" button for XFO and CSP violations,
      // since it's almost certainly useless. (Bug 553180)
      tryAgain.hidden = true;

      // Adding a button for opening websites blocked for CSP and XFO violations
      // in a new window. (Bug 1461195)
      document.getElementById("errorShortDesc").hidden = true;

      document.l10n.setAttributes(longDesc, "csp-xfo-blocked-long-desc", {
        hostname: HOST_NAME,
      });
      longDesc = null;

      document.getElementById("openInNewWindowContainer").hidden = false;

      const openInNewWindowButton = document.getElementById(
        "openInNewWindowButton"
      );
      openInNewWindowButton.href = document.location.href;

      // Add a learn more link
      learnMore.hidden = false;
      learnMoreLink.setAttribute("href", baseURL + "xframe-neterror-page");

      setupBlockingReportingUI();
      break;
    }

    case "dnsNotFound":
      pageTitleId = "neterror-dns-not-found-title";
      if (!isTRROnlyFailure) {
        RPMCheckAlternateHostAvailable();
      }

      break;
    case "inadequateSecurityError":
      // Remove the "Try again" button from pages that don't need it.
      // For HTTP/2 inadequate security, trying again won't help.
      tryAgain.hidden = true;
      break;

    case "malformedURI":
      pageTitleId = "neterror-malformed-uri-page-title";
      // Remove the "Try again" button from pages that don't need it.
      tryAgain.hidden = true;
      break;

    // Pinning errors are of type nssFailure2
    case "nssFailure2": {
      learnMore.hidden = false;

      const errorCode = document.getNetErrorInfo().errorCodeString;
      switch (errorCode) {
        case "SSL_ERROR_UNSUPPORTED_VERSION":
        case "SSL_ERROR_PROTOCOL_VERSION_ALERT": {
          const tlsNotice = document.getElementById("tlsVersionNotice");
          tlsNotice.hidden = false;
          document.l10n.setAttributes(tlsNotice, "cert-error-old-tls-version");
        }
        // fallthrough

        case "interrupted": // This happens with subresources that are above the max tls
        case "SSL_ERROR_NO_CIPHERS_SUPPORTED":
        case "SSL_ERROR_NO_CYPHER_OVERLAP":
        case "SSL_ERROR_SSL_DISABLED":
          RPMAddMessageListener("HasChangedCertPrefs", msg => {
            if (msg.data.hasChangedCertPrefs) {
              // Configuration overrides might have caused this; offer to reset.
              showPrefChangeContainer();
            }
          });
          RPMSendAsyncMessage("GetChangedCertPrefs");
      }

      break;
    }

    case "sslv3Used":
      learnMore.hidden = false;
      document.body.className = "certerror";
      break;
  }

  if (!KNOWN_ERROR_TITLE_IDS.has(bodyTitleId)) {
    console.error("No strings exist for error:", gErrorCode);
    bodyTitleId = "generic-title";
  }

  // The TRR errors may present options that direct users to settings only available on Firefox Desktop
  if (RPMIsFirefox()) {
    if (isTRROnlyFailure) {
      document.body.className = "certerror"; // Shows warning icon
      pageTitleId = "dns-not-found-trr-only-title2";
      document.l10n.setAttributes(docTitle, pageTitleId);
      bodyTitleId = "dns-not-found-trr-only-title2";
      document.l10n.setAttributes(bodyTitle, bodyTitleId);

      shortDesc.textContent = "";
      let skipReason = RPMGetTRRSkipReason();

      // enable buttons
      let trrExceptionButton = document.getElementById("trrExceptionButton");
      trrExceptionButton.addEventListener("click", () => {
        RPMSendQuery("Browser:AddTRRExcludedDomain", {
          hostname: HOST_NAME,
        }).then(msg => {
          retryThis(trrExceptionButton);
        });
      });

      let isTrrServerError = true;
      if (RPMIsSiteSpecificTRRError()) {
        // Only show the exclude button if the failure is specific to this
        // domain. If the TRR server is inaccessible we don't want to allow
        // the user to add an exception just for this domain.
        trrExceptionButton.hidden = false;
        isTrrServerError = false;
      }
      let trrSettingsButton = document.getElementById("trrSettingsButton");
      trrSettingsButton.addEventListener("click", () => {
        RPMSendAsyncMessage("OpenTRRPreferences");
      });
      trrSettingsButton.hidden = false;
      let message = document.getElementById("trrOnlyMessage");
      document.l10n.setAttributes(
        message,
        "neterror-dns-not-found-trr-only-reason",
        {
          hostname: HOST_NAME,
        }
      );

      let descriptionTag = "neterror-dns-not-found-trr-unknown-problem";
      let args = { trrDomain: RPMGetTRRDomain() };
      if (
        skipReason == "TRR_FAILED" ||
        skipReason == "TRR_CHANNEL_DNS_FAIL" ||
        skipReason == "TRR_UNKNOWN_CHANNEL_FAILURE" ||
        skipReason == "TRR_NET_REFUSED" ||
        skipReason == "TRR_NET_INTERRUPT" ||
        skipReason == "TRR_NET_INADEQ_SEQURITY"
      ) {
        descriptionTag = "neterror-dns-not-found-trr-only-could-not-connect";
      } else if (skipReason == "TRR_TIMEOUT") {
        descriptionTag = "neterror-dns-not-found-trr-only-timeout";
      } else if (
        skipReason == "TRR_IS_OFFLINE" ||
        skipReason == "TRR_NO_CONNECTIVITY"
      ) {
        descriptionTag = "neterror-dns-not-found-trr-offline";
      } else if (
        skipReason == "TRR_NO_ANSWERS" ||
        skipReason == "TRR_NXDOMAIN"
      ) {
        descriptionTag = "neterror-dns-not-found-trr-unknown-host2";
      } else if (
        skipReason == "TRR_DECODE_FAILED" ||
        skipReason == "TRR_SERVER_RESPONSE_ERR"
      ) {
        descriptionTag = "neterror-dns-not-found-trr-server-problem";
      }

      let trrMode = RPMGetIntPref("network.trr.mode").toString();
      recordTRREventTelemetry(
        "TRROnlyFailure",
        trrMode,
        args.trrDomain,
        skipReason
      );

      let description = document.getElementById("trrOnlyDescription");
      document.l10n.setAttributes(description, descriptionTag, args);

      const trrLearnMoreContainer = document.getElementById(
        "trrLearnMoreContainer"
      );
      trrLearnMoreContainer.hidden = false;
      let trrOnlyLearnMoreLink = document.getElementById(
        "trrOnlylearnMoreLink"
      );
      if (isTrrServerError) {
        // Go to DoH settings page
        trrOnlyLearnMoreLink.href = "about:preferences#privacy-doh";
        trrOnlyLearnMoreLink.addEventListener("click", event => {
          event.preventDefault();
          RPMSendAsyncMessage("OpenTRRPreferences");
          RPMRecordTelemetryEvent(
            "security.doh.neterror",
            "click",
            "settings_button",
            "TRROnlyFailure",
            {
              mode: trrMode,
              provider_key: args.trrDomain,
              skip_reason: skipReason,
            }
          );
        });
      } else {
        // This will be replaced at a later point with a link to an offline support page
        // https://bugzilla.mozilla.org/show_bug.cgi?id=1806257
        trrOnlyLearnMoreLink.href =
          RPMGetFormatURLPref("network.trr_ui.skip_reason_learn_more_url") +
          skipReason.toLowerCase().replaceAll("_", "-");
      }

      let div = document.getElementById("trrOnlyContainer");
      div.hidden = false;

      return;
    } else if (isNativeFallbackWarning) {
      showNativeFallbackWarning();
      return;
    }
  }

  document.l10n.setAttributes(docTitle, pageTitleId);
  document.l10n.setAttributes(bodyTitle, bodyTitleId);

  shortDesc.textContent = getDescription();
  setFocus("#netErrorButtonContainer > .try-again");

  if (longDesc) {
    const parts = getNetErrorDescParts();
    setNetErrorMessageFromParts(longDesc, parts);
  }

  setNetErrorMessageFromCode();
}

function showNativeFallbackWarning() {
  const docTitle = document.querySelector("title");
  const bodyTitle = document.querySelector(".title-text");
  const shortDesc = document.getElementById("errorShortDesc");

  let pageTitleId = "neterror-page-title";
  let bodyTitleId = gErrorCode + "-title";

  document.body.className = "certerror"; // Shows warning icon
  pageTitleId = "dns-not-found-native-fallback-title2";
  document.l10n.setAttributes(docTitle, pageTitleId);

  bodyTitleId = "dns-not-found-native-fallback-title2";
  document.l10n.setAttributes(bodyTitle, bodyTitleId);

  shortDesc.textContent = "";
  let nativeFallbackIgnoreButton = document.getElementById(
    "nativeFallbackIgnoreButton"
  );
  nativeFallbackIgnoreButton.addEventListener("click", () => {
    RPMSetBoolPref("network.trr.display_fallback_warning", false);
    retryThis(nativeFallbackIgnoreButton);
  });

  let continueThisTimeButton = document.getElementById(
    "nativeFallbackContinueThisTimeButton"
  );
  continueThisTimeButton.addEventListener("click", () => {
    RPMSetTRRDisabledLoadFlags();
    document.location.reload();
  });
  continueThisTimeButton.hidden = false;

  nativeFallbackIgnoreButton.hidden = false;
  let message = document.getElementById("nativeFallbackMessage");
  document.l10n.setAttributes(
    message,
    "neterror-dns-not-found-native-fallback-reason",
    {
      hostname: HOST_NAME,
    }
  );
  let skipReason = RPMGetTRRSkipReason();
  let descriptionTag = "neterror-dns-not-found-trr-unknown-problem";
  let args = { trrDomain: RPMGetTRRDomain() };

  if (skipReason.includes("HEURISTIC_TRIPPED")) {
    descriptionTag = "neterror-dns-not-found-native-fallback-heuristic";
  } else if (skipReason == "TRR_NOT_CONFIRMED") {
    descriptionTag = "neterror-dns-not-found-native-fallback-not-confirmed2";
  }

  let description = document.getElementById("nativeFallbackDescription");
  document.l10n.setAttributes(description, descriptionTag, args);

  let learnMoreContainer = document.getElementById(
    "nativeFallbackLearnMoreContainer"
  );
  learnMoreContainer.hidden = false;

  let learnMoreLink = document.getElementById("nativeFallbackLearnMoreLink");
  learnMoreLink.href =
    RPMGetFormatURLPref("network.trr_ui.skip_reason_learn_more_url") +
    skipReason.toLowerCase().replaceAll("_", "-");

  let div = document.getElementById("nativeFallbackContainer");
  div.hidden = false;

  recordTRREventTelemetry(
    "NativeFallbackWarning",
    RPMGetIntPref("network.trr.mode").toString(),
    args.trrDomain,
    skipReason
  );
}
/**
 * Builds HTML elements from `parts` and appends them to `parentElement`.
 *
 * @param {HTMLElement} parentElement
 * @param {Array<["li" | "p" | "span", string, Record<string, string> | undefined]>} parts
 */
function setNetErrorMessageFromParts(parentElement, parts) {
  let list = null;

  for (let [tag, l10nId, l10nArgs] of parts) {
    const elem = document.createElement(tag);
    elem.dataset.l10nId = l10nId;
    if (l10nArgs) {
      elem.dataset.l10nArgs = JSON.stringify(l10nArgs);
    }

    if (tag === "li") {
      if (!list) {
        list = document.createElement("ul");
        parentElement.appendChild(list);
      }
      list.appendChild(elem);
    } else {
      if (list) {
        list = null;
      }
      parentElement.appendChild(elem);
    }
  }
}

/**
 * Returns an array of tuples determining the parts of an error message:
 * - HTML tag name
 * - l10n id
 * - l10n args (optional)
 *
 * @returns { Array<["li" | "p" | "span", string, Record<string, string> | undefined]> }
 */
function getNetErrorDescParts() {
  switch (gErrorCode) {
    case "connectionFailure":
    case "netInterrupt":
    case "netReset":
    case "netTimeout":
      return [
        ["li", "neterror-load-error-try-again"],
        ["li", "neterror-load-error-connection"],
        ["li", "neterror-load-error-firewall"],
      ];

    case "blockedByPolicy":
    case "deniedPortAccess":
    case "malformedURI":
      return [];

    case "captivePortal":
      return [["p", ""]];
    case "contentEncodingError":
      return [["li", "neterror-content-encoding-error"]];
    case "corruptedContentErrorv2":
      return [
        ["p", "neterror-corrupted-content-intro"],
        ["li", "neterror-corrupted-content-contact-website"],
      ];
    case "dnsNotFound":
      return [
        ["span", "neterror-dns-not-found-hint-header"],
        ["li", "neterror-dns-not-found-hint-try-again"],
        ["li", "neterror-dns-not-found-hint-check-network"],
        ["li", "neterror-dns-not-found-hint-firewall"],
      ];
    case "fileAccessDenied":
      return [["li", "neterror-access-denied"]];
    case "fileNotFound":
      return [
        ["li", "neterror-file-not-found-filename"],
        ["li", "neterror-file-not-found-moved"],
      ];
    case "inadequateSecurityError":
      return [
        ["p", "neterror-inadequate-security-intro", { hostname: HOST_NAME }],
        ["p", "neterror-inadequate-security-code"],
      ];
    case "mitm": {
      const failedCertInfo = document.getFailedCertSecurityInfo();
      const errArgs = {
        hostname: HOST_NAME,
        mitm: getMitmName(failedCertInfo),
      };
      return [["span", "certerror-mitm", errArgs]];
    }
    case "netOffline":
      return [["li", "neterror-net-offline"]];
    case "networkProtocolError":
      return [
        ["p", "neterror-network-protocol-error-intro"],
        ["li", "neterror-network-protocol-error-contact-website"],
      ];
    case "notCached":
      return [
        ["p", "neterror-not-cached-intro"],
        ["li", "neterror-not-cached-sensitive"],
        ["li", "neterror-not-cached-try-again"],
      ];
    case "nssFailure2":
      return [
        ["li", "neterror-nss-failure-not-verified"],
        ["li", "neterror-nss-failure-contact-website"],
      ];
    case "proxyConnectFailure":
      return [
        ["li", "neterror-proxy-connect-failure-settings"],
        ["li", "neterror-proxy-connect-failure-contact-admin"],
      ];
    case "proxyResolveFailure":
      return [
        ["li", "neterror-proxy-resolve-failure-settings"],
        ["li", "neterror-proxy-resolve-failure-connection"],
        ["li", "neterror-proxy-resolve-failure-firewall"],
      ];
    case "redirectLoop":
      return [["li", "neterror-redirect-loop"]];
    case "sslv3Used":
      return [["span", "neterror-sslv3-used"]];
    case "unknownProtocolFound":
      return [["li", "neterror-unknown-protocol"]];
    case "unknownSocketType":
      return [
        ["li", "neterror-unknown-socket-type-psm-installed"],
        ["li", "neterror-unknown-socket-type-server-config"],
      ];
    case "unsafeContentType":
      return [["li", "neterror-unsafe-content-type"]];

    default:
      return [["p", "neterror-generic-error"]];
  }
}

function setNetErrorMessageFromCode() {
  let errorCode;
  try {
    errorCode = document.getNetErrorInfo().errorCodeString;
  } catch (ex) {
    // We don't have a securityInfo when this is for example a DNS error.
    return;
  }

  let errorMessage;
  if (errorCode) {
    const l10nId = errorCode.replace(/_/g, "-").toLowerCase();
    if (KNOWN_ERROR_MESSAGE_IDS.has(l10nId)) {
      const l10n = new Localization([ERROR_MESSAGES_FTL], true);
      errorMessage = l10n.formatValueSync(l10nId);
    }

    const shortDesc2 = document.getElementById("errorShortDesc2");
    document.l10n.setAttributes(shortDesc2, "cert-error-code-prefix", {
      error: errorCode,
    });
  } else {
    console.warn("This error page has no error code in its security info");
  }

  let hostname = HOST_NAME;
  const { port } = document.location;
  if (port && port != 443) {
    hostname += ":" + port;
  }

  const shortDesc = document.getElementById("errorShortDesc");
  document.l10n.setAttributes(shortDesc, "cert-error-ssl-connection-error", {
    errorMessage: errorMessage ?? errorCode ?? "",
    hostname,
  });
}

function setupBlockingReportingUI() {
  let checkbox = document.getElementById("automaticallyReportBlockingInFuture");

  let reportingAutomatic = RPMGetBoolPref(
    "security.xfocsp.errorReporting.automatic"
  );
  checkbox.checked = !!reportingAutomatic;

  checkbox.addEventListener("change", function ({ target: { checked } }) {
    RPMSetBoolPref("security.xfocsp.errorReporting.automatic", checked);

    // If we're enabling reports, send a report for this failure.
    if (checked) {
      reportBlockingError();
    }
  });

  let reportingEnabled = RPMGetBoolPref(
    "security.xfocsp.errorReporting.enabled"
  );

  if (reportingEnabled) {
    // Display blocking error reporting UI for XFO error and CSP error.
    document.getElementById("blockingErrorReporting").hidden = false;

    if (reportingAutomatic) {
      reportBlockingError();
    }
  }
}

function reportBlockingError() {
  // We only report if we are in a frame.
  if (window === window.top) {
    return;
  }

  let err = gErrorCode;
  // Ensure we only deal with XFO and CSP here.
  if (!["xfoBlocked", "cspBlocked"].includes(err)) {
    return;
  }

  let xfo_header = RPMGetHttpResponseHeader("X-Frame-Options");
  let csp_header = RPMGetHttpResponseHeader("Content-Security-Policy");

  // Extract the 'CSP: frame-ancestors' from the CSP header.
  let reg = /(?:^|\s)frame-ancestors\s([^;]*)[$]*/i;
  let match = reg.exec(csp_header);
  csp_header = match ? match[1] : "";

  // If it's the csp error page without the CSP: frame-ancestors, this means
  // this error page is not triggered by CSP: frame-ancestors. So, we bail out
  // early.
  if (err === "cspBlocked" && !csp_header) {
    return;
  }

  let xfoAndCspInfo = {
    error_type: err === "xfoBlocked" ? "xfo" : "csp",
    xfo_header,
    csp_header,
  };

  // Trimming the tail colon symbol.
  let scheme = document.location.protocol.slice(0, -1);

  RPMSendAsyncMessage("ReportBlockingError", {
    scheme,
    host: document.location.host,
    port: parseInt(document.location.port) || -1,
    path: document.location.pathname,
    xfoAndCspInfo,
  });
}

function initPageCaptivePortal() {
  document.body.className = "captiveportal";
  document.getElementById("returnButton").hidden = true;
  const openButton = document.getElementById("openPortalLoginPageButton");
  openButton.hidden = false;
  openButton.addEventListener("click", () => {
    RPMSendAsyncMessage("Browser:OpenCaptivePortalPage");
  });

  setFocus("#openPortalLoginPageButton");
  setupAdvancedButton();
  disallowCertOverridesIfNeeded();

  // When the portal is freed, an event is sent by the parent process
  // that we can pick up and attempt to reload the original page.
  RPMAddMessageListener("AboutNetErrorCaptivePortalFreed", () => {
    document.location.reload();
  });
}

function initPageCertError() {
  document.body.classList.add("certerror");

  setFocus("#returnButton");
  setupAdvancedButton();
  disallowCertOverridesIfNeeded();

  const hideAddExceptionButton = RPMGetBoolPref(
    "security.certerror.hideAddException",
    false
  );
  if (hideAddExceptionButton) {
    document.getElementById("exceptionDialogButton").hidden = true;
  }

  const els = document.querySelectorAll("[data-telemetry-id]");
  for (let el of els) {
    el.addEventListener("click", recordClickTelemetry);
  }

  const failedCertInfo = document.getFailedCertSecurityInfo();
  // Truncate the error code to avoid going over the allowed
  // string size limit for telemetry events.
  const errorCode = failedCertInfo.errorCodeString.substring(0, 40);
  RPMRecordTelemetryEvent(
    "security.ui.certerror",
    "load",
    "aboutcerterror",
    errorCode,
    {
      has_sts: gHasSts.toString(),
      is_frame: (window.parent != window).toString(),
    }
  );

  setCertErrorDetails();
}

function recordClickTelemetry(e) {
  let target = e.originalTarget;
  let telemetryId = target.dataset.telemetryId;
  let failedCertInfo = document.getFailedCertSecurityInfo();
  // Truncate the error code to avoid going over the allowed
  // string size limit for telemetry events.
  let errorCode = failedCertInfo.errorCodeString.substring(0, 40);
  RPMRecordTelemetryEvent(
    "security.ui.certerror",
    "click",
    telemetryId,
    errorCode,
    {
      has_sts: gHasSts.toString(),
      is_frame: (window.parent != window).toString(),
    }
  );
}

function initCertErrorPageActions() {
  document.getElementById(
    "certErrorAndCaptivePortalButtonContainer"
  ).hidden = false;
  document
    .getElementById("returnButton")
    .addEventListener("click", onReturnButtonClick);
  document
    .getElementById("advancedPanelReturnButton")
    .addEventListener("click", onReturnButtonClick);
  document
    .getElementById("copyToClipboardTop")
    .addEventListener("click", copyPEMToClipboard);
  document
    .getElementById("copyToClipboardBottom")
    .addEventListener("click", copyPEMToClipboard);
  document
    .getElementById("exceptionDialogButton")
    .addEventListener("click", addCertException);
}

function addCertException() {
  const isPermanent =
    !RPMIsWindowPrivate() &&
    RPMGetBoolPref("security.certerrors.permanentOverride");
  document.addCertException(!isPermanent).then(
    () => {
      location.reload();
    },
    err => {}
  );
}

function onReturnButtonClick(e) {
  RPMSendAsyncMessage("Browser:SSLErrorGoBack");
}

function copyPEMToClipboard(e) {
  const errorText = document.getElementById("certificateErrorText");
  navigator.clipboard.writeText(errorText.textContent);
}

async function getFailedCertificatesAsPEMString() {
  let locationUrl = document.location.href;
  let failedCertInfo = document.getFailedCertSecurityInfo();
  let errorMessage = failedCertInfo.errorMessage;
  let hasHSTS = failedCertInfo.hasHSTS.toString();
  let hasHPKP = failedCertInfo.hasHPKP.toString();
  let [hstsLabel, hpkpLabel, failedChainLabel] =
    await document.l10n.formatValues([
      { id: "cert-error-details-hsts-label", args: { hasHSTS } },
      { id: "cert-error-details-key-pinning-label", args: { hasHPKP } },
      { id: "cert-error-details-cert-chain-label" },
    ]);

  let certStrings = failedCertInfo.certChainStrings;
  let failedChainCertificates = "";
  for (let der64 of certStrings) {
    let wrapped = der64.replace(/(\S{64}(?!$))/g, "$1\r\n");
    failedChainCertificates +=
      "-----BEGIN CERTIFICATE-----\r\n" +
      wrapped +
      "\r\n-----END CERTIFICATE-----\r\n";
  }

  let details =
    locationUrl +
    "\r\n\r\n" +
    errorMessage +
    "\r\n\r\n" +
    hstsLabel +
    "\r\n" +
    hpkpLabel +
    "\r\n\r\n" +
    failedChainLabel +
    "\r\n\r\n" +
    failedChainCertificates;
  return details;
}

function setCertErrorDetails() {
  // Check if the connection is being man-in-the-middled. When the parent
  // detects an intercepted connection, the page may be reloaded with a new
  // error code (MOZILLA_PKIX_ERROR_MITM_DETECTED).
  const failedCertInfo = document.getFailedCertSecurityInfo();
  const mitmPrimingEnabled = RPMGetBoolPref(
    "security.certerrors.mitm.priming.enabled"
  );
  if (
    mitmPrimingEnabled &&
    failedCertInfo.errorCodeString == "SEC_ERROR_UNKNOWN_ISSUER" &&
    // Only do this check for top-level failures.
    window.parent == window
  ) {
    RPMSendAsyncMessage("Browser:PrimeMitm");
  }

  document.body.setAttribute("code", failedCertInfo.errorCodeString);

  const learnMore = document.getElementById("learnMoreContainer");
  learnMore.hidden = false;
  const learnMoreLink = document.getElementById("learnMoreLink");
  const baseURL = RPMGetFormatURLPref("app.support.baseURL");
  learnMoreLink.href = baseURL + "connection-not-secure";

  const bodyTitle = document.querySelector(".title-text");
  const shortDesc = document.getElementById("errorShortDesc");
  const shortDesc2 = document.getElementById("errorShortDesc2");

  let whatToDoParts = null;

  switch (failedCertInfo.errorCodeString) {
    case "SSL_ERROR_BAD_CERT_DOMAIN":
      whatToDoParts = [
        ["p", "certerror-bad-cert-domain-what-can-you-do-about-it"],
      ];
      break;

    case "SEC_ERROR_OCSP_INVALID_SIGNING_CERT": // FIXME - this would have thrown?
      break;

    case "SEC_ERROR_UNKNOWN_ISSUER":
      whatToDoParts = [
        ["p", "certerror-unknown-issuer-what-can-you-do-about-it-website"],
        [
          "p",
          "certerror-unknown-issuer-what-can-you-do-about-it-contact-admin",
        ],
      ];
      break;

    // This error code currently only exists for the Symantec distrust
    // in Firefox 63, so we add copy explaining that to the user.
    // In case of future distrusts of that scale we might need to add
    // additional parameters that allow us to identify the affected party
    // without replicating the complex logic from certverifier code.
    case "MOZILLA_PKIX_ERROR_ADDITIONAL_POLICY_CONSTRAINT_FAILED": {
      document.l10n.setAttributes(
        shortDesc2,
        "cert-error-symantec-distrust-description",
        { hostname: HOST_NAME }
      );

      // FIXME - this does nothing
      const adminDesc = document.createElement("p");
      document.l10n.setAttributes(
        adminDesc,
        "cert-error-symantec-distrust-admin"
      );

      learnMoreLink.href = baseURL + "symantec-warning";
      break;
    }

    case "MOZILLA_PKIX_ERROR_MITM_DETECTED": {
      const autoEnabledEnterpriseRoots = RPMGetBoolPref(
        "security.enterprise_roots.auto-enabled",
        false
      );
      if (mitmPrimingEnabled && autoEnabledEnterpriseRoots) {
        RPMSendAsyncMessage("Browser:ResetEnterpriseRootsPref");
      }

      learnMoreLink.href = baseURL + "security-error";

      document.l10n.setAttributes(bodyTitle, "certerror-mitm-title");

      document.l10n.setAttributes(shortDesc, "certerror-mitm", {
        hostname: HOST_NAME,
        mitm: getMitmName(failedCertInfo),
      });

      const id3 = gHasSts
        ? "certerror-mitm-what-can-you-do-about-it-attack-sts"
        : "certerror-mitm-what-can-you-do-about-it-attack";
      whatToDoParts = [
        ["li", "certerror-mitm-what-can-you-do-about-it-antivirus"],
        ["li", "certerror-mitm-what-can-you-do-about-it-corporate"],
        ["li", id3, { mitm: getMitmName(failedCertInfo) }],
      ];
      break;
    }

    case "MOZILLA_PKIX_ERROR_SELF_SIGNED_CERT":
      learnMoreLink.href = baseURL + "security-error";
      break;

    // In case the certificate expired we make sure the system clock
    // matches the remote-settings service (blocklist via Kinto) ping time
    // and is not before the build date.
    case "SEC_ERROR_EXPIRED_CERTIFICATE":
    case "SEC_ERROR_EXPIRED_ISSUER_CERTIFICATE":
    case "MOZILLA_PKIX_ERROR_NOT_YET_VALID_CERTIFICATE":
    case "MOZILLA_PKIX_ERROR_NOT_YET_VALID_ISSUER_CERTIFICATE": {
      learnMoreLink.href = baseURL + "time-errors";

      // We check against the remote-settings server time first if available, because that allows us
      // to give the user an approximation of what the correct time is.
      const difference = RPMGetIntPref(
        "services.settings.clock_skew_seconds",
        0
      );
      const lastFetched =
        RPMGetIntPref("services.settings.last_update_seconds", 0) * 1000;

      // This is set to true later if the user's system clock is at fault for this error.
      let clockSkew = false;

      const now = Date.now();
      const certRange = {
        notBefore: failedCertInfo.certValidityRangeNotBefore,
        notAfter: failedCertInfo.certValidityRangeNotAfter,
      };
      const approximateDate = now - difference * 1000;
      // If the difference is more than a day, we last fetched the date in the last 5 days,
      // and adjusting the date per the interval would make the cert valid, warn the user:
      if (
        Math.abs(difference) > 60 * 60 * 24 &&
        now - lastFetched <= 60 * 60 * 24 * 5 * 1000 &&
        certRange.notBefore < approximateDate &&
        certRange.notAfter > approximateDate
      ) {
        clockSkew = true;
        // If there is no clock skew with Kinto servers, check against the build date.
        // (The Kinto ping could have happened when the time was still right, or not at all)
      } else {
        const appBuildID = RPMGetAppBuildID();
        const year = parseInt(appBuildID.substr(0, 4), 10);
        const month = parseInt(appBuildID.substr(4, 2), 10) - 1;
        const day = parseInt(appBuildID.substr(6, 2), 10);

        const buildDate = new Date(year, month, day);

        // We don't check the notBefore of the cert with the build date,
        // as it is of course almost certain that it is now later than the build date,
        // so we shouldn't exclude the possibility that the cert has become valid
        // since the build date.
        if (buildDate > now && new Date(certRange.notAfter) > buildDate) {
          clockSkew = true;
        }
      }

      if (clockSkew) {
        document.body.classList.add("clockSkewError");
        document.l10n.setAttributes(bodyTitle, "clockSkewError-title");
        document.l10n.setAttributes(shortDesc, "neterror-clock-skew-error", {
          hostname: HOST_NAME,
          now,
        });
        document.getElementById("returnButton").hidden = true;
        document.getElementById("certErrorTryAgainButton").hidden = false;
        document.getElementById("advancedButton").hidden = true;

        document.getElementById("advancedPanelReturnButton").hidden = true;
        document.getElementById("advancedPanelTryAgainButton").hidden = false;
        document.getElementById("exceptionDialogButton").hidden = true;
        break;
      }

      document.l10n.setAttributes(shortDesc, "certerror-expired-cert-intro", {
        hostname: HOST_NAME,
      });

      // The secondary description mentions expired certificates explicitly
      // and should only be shown if the certificate has actually expired
      // instead of being not yet valid.
      if (failedCertInfo.errorCodeString == "SEC_ERROR_EXPIRED_CERTIFICATE") {
        const sd2Id = gHasSts
          ? "certerror-expired-cert-sts-second-para"
          : "certerror-expired-cert-second-para";
        document.l10n.setAttributes(shortDesc2, sd2Id);
        if (
          Math.abs(difference) <= 60 * 60 * 24 &&
          now - lastFetched <= 60 * 60 * 24 * 5 * 1000
        ) {
          whatToDoParts = [
            ["p", "certerror-bad-cert-domain-what-can-you-do-about-it"],
          ];
        }
      }

      whatToDoParts ??= [
        [
          "p",
          "certerror-expired-cert-what-can-you-do-about-it-clock",
          { hostname: HOST_NAME, now },
        ],
        [
          "p",
          "certerror-expired-cert-what-can-you-do-about-it-contact-website",
        ],
      ];
      break;
    }
  }

  if (whatToDoParts) {
    setNetErrorMessageFromParts(
      document.getElementById("errorWhatToDoText"),
      whatToDoParts
    );
    document.getElementById("errorWhatToDo").hidden = false;
  }
}

async function getSubjectAltNames(failedCertInfo) {
  const serverCertBase64 = failedCertInfo.certChainStrings[0];
  const parsed = await parse(pemToDER(serverCertBase64));
  const subjectAltNamesExtension = parsed.ext.san;
  const subjectAltNames = [];
  if (subjectAltNamesExtension) {
    for (let [key, value] of subjectAltNamesExtension.altNames) {
      if (key === "DNS Name" && value.length) {
        subjectAltNames.push(value);
      }
    }
  }
  return subjectAltNames;
}

// The optional argument is only here for testing purposes.
function setTechnicalDetailsOnCertError(
  failedCertInfo = document.getFailedCertSecurityInfo()
) {
  let technicalInfo = document.getElementById("badCertTechnicalInfo");
  technicalInfo.textContent = "";

  function addLabel(l10nId, args = null, attrs = null) {
    let elem = document.createElement("label");
    technicalInfo.appendChild(elem);

    let newLines = document.createTextNode("\n \n");
    technicalInfo.appendChild(newLines);

    if (attrs) {
      let link = document.createElement("a");
      for (let [attr, value] of Object.entries(attrs)) {
        link.setAttribute(attr, value);
      }
      elem.appendChild(link);
    }

    document.l10n.setAttributes(elem, l10nId, args);
  }

  function addErrorCodeLink() {
    addLabel(
      "cert-error-code-prefix-link",
      { error: failedCertInfo.errorCodeString },
      {
        title: failedCertInfo.errorCodeString,
        id: "errorCode",
        "data-l10n-name": "error-code-link",
        "data-telemetry-id": "error_code_link",
        href: "#certificateErrorDebugInformation",
      }
    );

    // We're attaching the event listener to the parent element and not on
    // the errorCodeLink itself because event listeners cannot be attached
    // to fluent DOM overlays.
    technicalInfo.addEventListener("click", event => {
      if (event.target.id === "errorCode") {
        event.preventDefault();
        toggleCertErrorDebugInfoVisibility();
        recordClickTelemetry(event);
      }
    });
  }

  let hostname = HOST_NAME;
  const { port } = document.location;
  if (port && port != 443) {
    hostname += ":" + port;
  }

  switch (failedCertInfo.overridableErrorCategory) {
    case "trust-error":
      switch (failedCertInfo.errorCodeString) {
        case "MOZILLA_PKIX_ERROR_MITM_DETECTED":
          addLabel("cert-error-mitm-intro");
          addLabel("cert-error-mitm-mozilla");
          addLabel("cert-error-mitm-connection");
          break;
        case "SEC_ERROR_UNKNOWN_ISSUER":
          addLabel("cert-error-trust-unknown-issuer-intro");
          addLabel("cert-error-trust-unknown-issuer", { hostname });
          break;
        case "SEC_ERROR_CA_CERT_INVALID":
          addLabel("cert-error-intro", { hostname });
          addLabel("cert-error-trust-cert-invalid");
          break;
        case "SEC_ERROR_UNTRUSTED_ISSUER":
          addLabel("cert-error-intro", { hostname });
          addLabel("cert-error-trust-untrusted-issuer");
          break;
        case "SEC_ERROR_CERT_SIGNATURE_ALGORITHM_DISABLED":
          addLabel("cert-error-intro", { hostname });
          addLabel("cert-error-trust-signature-algorithm-disabled");
          break;
        case "SEC_ERROR_EXPIRED_ISSUER_CERTIFICATE":
          addLabel("cert-error-intro", { hostname });
          addLabel("cert-error-trust-expired-issuer");
          break;
        case "MOZILLA_PKIX_ERROR_SELF_SIGNED_CERT":
          addLabel("cert-error-intro", { hostname });
          addLabel("cert-error-trust-self-signed");
          break;
        case "MOZILLA_PKIX_ERROR_ADDITIONAL_POLICY_CONSTRAINT_FAILED":
          addLabel("cert-error-intro", { hostname });
          addLabel("cert-error-trust-symantec");
          break;
        default:
          addLabel("cert-error-intro", { hostname });
          addLabel("cert-error-untrusted-default");
      }
      addErrorCodeLink();
      break;

    case "expired-or-not-yet-valid": {
      const notBefore = failedCertInfo.validNotBefore;
      const notAfter = failedCertInfo.validNotAfter;
      if (notBefore && Date.now() < notAfter) {
        addLabel("cert-error-not-yet-valid-now", {
          hostname,
          "not-before-local-time": formatter.format(new Date(notBefore)),
        });
      } else {
        addLabel("cert-error-expired-now", {
          hostname,
          "not-after-local-time": formatter.format(new Date(notAfter)),
        });
      }
      addErrorCodeLink();
      break;
    }

    case "domain-mismatch":
      getSubjectAltNames(failedCertInfo).then(subjectAltNames => {
        if (!subjectAltNames.length) {
          addLabel("cert-error-domain-mismatch", { hostname });
        } else if (subjectAltNames.length > 1) {
          const names = subjectAltNames.join(", ");
          addLabel("cert-error-domain-mismatch-multiple", {
            hostname,
            "subject-alt-names": names,
          });
        } else {
          const altName = subjectAltNames[0];

          // If the alt name is a wildcard domain ("*.example.com")
          // let's use "www" instead.  "*.example.com" isn't going to
          // get anyone anywhere useful. bug 432491
          const okHost = altName.replace(/^\*\./, "www.");

          // Let's check if we want to make this a link.
          const showLink =
            /* case #1:
             * example.com uses an invalid security certificate.
             *
             * The certificate is only valid for www.example.com
             *
             * Make sure to include the "." ahead of thisHost so that a
             * MitM attack on paypal.com doesn't hyperlink to "notpaypal.com"
             *
             * We'd normally just use a RegExp here except that we lack a
             * library function to escape them properly (bug 248062), and
             * domain names are famous for having '.' characters in them,
             * which would allow spurious and possibly hostile matches.
             */
            okHost.endsWith("." + HOST_NAME) ||
            /* case #2:
             * browser.garage.maemo.org uses an invalid security certificate.
             *
             * The certificate is only valid for garage.maemo.org
             */
            HOST_NAME.endsWith("." + okHost);

          const l10nArgs = { hostname, "alt-name": altName };
          if (showLink) {
            // Set the link if we want it.
            const proto = document.location.protocol + "//";
            addLabel("cert-error-domain-mismatch-single", l10nArgs, {
              href: proto + okHost,
              "data-l10n-name": "domain-mismatch-link",
              id: "cert_domain_link",
            });

            // If we set a link, meaning there's something helpful for
            // the user here, expand the section by default
            if (getCSSClass() != "expertBadCert") {
              revealAdvancedPanelSlowlyAsync();
            }
          } else {
            addLabel("cert-error-domain-mismatch-single-nolink", l10nArgs);
          }
        }
        addErrorCodeLink();
      });
      break;
  }

  getFailedCertificatesAsPEMString().then(pemString => {
    const errorText = document.getElementById("certificateErrorText");
    errorText.textContent = pemString;
  });
}

/* Only focus if we're the toplevel frame; otherwise we
   don't want to call attention to ourselves!
*/
function setFocus(selector, position = "afterbegin") {
  if (window.top == window) {
    var button = document.querySelector(selector);
    button.parentNode.insertAdjacentElement(position, button);
    // It's possible setFocus was called via the DOMContentLoaded event
    // handler and that the button has no frame. Things without a frame cannot
    // be focused. We use a requestAnimationFrame to queue up the focus to occur
    // once the button has its frame.
    requestAnimationFrame(() => {
      button.focus({ focusVisible: false });
    });
  }
}

for (let button of document.querySelectorAll(".try-again")) {
  button.addEventListener("click", function () {
    retryThis(this);
  });
}

initPage();

// Dispatch this event so tests can detect that we finished loading the error page.
document.dispatchEvent(new CustomEvent("AboutNetErrorLoad", { bubbles: true }));