summaryrefslogtreecommitdiffstats
path: root/toolkit/mozapps/extensions/internal/AddonUpdateChecker.jsm
blob: fb2563f75f7169f200385235431cf5f290405008 (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
/* 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/. */

/**
 * The AddonUpdateChecker is responsible for retrieving the update information
 * from an add-on's remote update manifest.
 */

"use strict";

const Cc = Components.classes;
const Ci = Components.interfaces;
const Cu = Components.utils;

this.EXPORTED_SYMBOLS = [ "AddonUpdateChecker" ];

const TIMEOUT                         = 60 * 1000;
const PREFIX_NS_RDF                   = "http://www.w3.org/1999/02/22-rdf-syntax-ns#";
const PREFIX_NS_EM                    = "http://www.mozilla.org/2004/em-rdf#";
const PREFIX_ITEM                     = "urn:mozilla:item:";
const PREFIX_EXTENSION                = "urn:mozilla:extension:";
const PREFIX_THEME                    = "urn:mozilla:theme:";
const XMLURI_PARSE_ERROR              = "http://www.mozilla.org/newlayout/xml/parsererror.xml";

const TOOLKIT_ID                      = "toolkit@mozilla.org";
const FIREFOX_ID                      = "{ec8030f7-c20a-464f-9b0e-13a3a9e97384}";
const FIREFOX_APPCOMPATVERSION        = "56.9"

const PREF_UPDATE_REQUIREBUILTINCERTS = "extensions.update.requireBuiltInCerts";
const PREF_EM_MIN_COMPAT_APP_VERSION  = "extensions.minCompatibleAppVersion";

Components.utils.import("resource://gre/modules/Services.jsm");
Components.utils.import("resource://gre/modules/XPCOMUtils.jsm");

XPCOMUtils.defineLazyModuleGetter(this, "AddonManager",
                                  "resource://gre/modules/AddonManager.jsm");
XPCOMUtils.defineLazyModuleGetter(this, "AddonManagerPrivate",
                                  "resource://gre/modules/AddonManager.jsm");
XPCOMUtils.defineLazyModuleGetter(this, "AddonRepository",
                                  "resource://gre/modules/addons/AddonRepository.jsm");
XPCOMUtils.defineLazyModuleGetter(this, "ServiceRequest",
                                  "resource://gre/modules/ServiceRequest.jsm");


// Shared code for suppressing bad cert dialogs.
XPCOMUtils.defineLazyGetter(this, "CertUtils", function() {
  let certUtils = {};
  Components.utils.import("resource://gre/modules/CertUtils.jsm", certUtils);
  return certUtils;
});

var gRDF = Cc["@mozilla.org/rdf/rdf-service;1"].
           getService(Ci.nsIRDFService);

Cu.import("resource://gre/modules/Log.jsm");
const LOGGER_ID = "addons.update-checker";

// Create a new logger for use by the Addons Update Checker
// (Requires AddonManager.jsm)
var logger = Log.repository.getLogger(LOGGER_ID);

/**
 * A serialisation method for RDF data that produces an identical string
 * for matching RDF graphs.
 * The serialisation is not complete, only assertions stemming from a given
 * resource are included, multiple references to the same resource are not
 * permitted, and the RDF prolog and epilog are not included.
 * RDF Blob and Date literals are not supported.
 */
function RDFSerializer() {
  this.cUtils = Cc["@mozilla.org/rdf/container-utils;1"].
                getService(Ci.nsIRDFContainerUtils);
  this.resources = [];
}

RDFSerializer.prototype = {
  INDENT: "  ",      // The indent used for pretty-printing
  resources: null,   // Array of the resources that have been found

  /**
   * Escapes characters from a string that should not appear in XML.
   *
   * @param  aString
   *         The string to be escaped
   * @return a string with all characters invalid in XML character data
   *         converted to entity references.
   */
  escapeEntities: function(aString) {
    aString = aString.replace(/&/g, "&");
    aString = aString.replace(/</g, "&lt;");
    aString = aString.replace(/>/g, "&gt;");
    return aString.replace(/"/g, "&quot;");
  },

  /**
   * Serializes all the elements of an RDF container.
   *
   * @param  aDs
   *         The RDF datasource
   * @param  aContainer
   *         The RDF container to output the child elements of
   * @param  aIndent
   *         The current level of indent for pretty-printing
   * @return a string containing the serialized elements.
   */
  serializeContainerItems: function(aDs, aContainer, aIndent) {
    var result = "";
    var items = aContainer.GetElements();
    while (items.hasMoreElements()) {
      var item = items.getNext().QueryInterface(Ci.nsIRDFResource);
      result += aIndent + "<RDF:li>\n"
      result += this.serializeResource(aDs, item, aIndent + this.INDENT);
      result += aIndent + "</RDF:li>\n"
    }
    return result;
  },

  /**
   * Serializes all em:* (see EM_NS) properties of an RDF resource except for
   * the em:signature property. As this serialization is to be compared against
   * the manifest signature it cannot contain the em:signature property itself.
   *
   * @param  aDs
   *         The RDF datasource
   * @param  aResource
   *         The RDF resource that contains the properties to serialize
   * @param  aIndent
   *         The current level of indent for pretty-printing
   * @return a string containing the serialized properties.
   * @throws if the resource contains a property that cannot be serialized
   */
  serializeResourceProperties: function(aDs, aResource, aIndent) {
    var result = "";
    var items = [];
    var arcs = aDs.ArcLabelsOut(aResource);
    while (arcs.hasMoreElements()) {
      var arc = arcs.getNext().QueryInterface(Ci.nsIRDFResource);
      if (arc.ValueUTF8.substring(0, PREFIX_NS_EM.length) != PREFIX_NS_EM)
        continue;
      var prop = arc.ValueUTF8.substring(PREFIX_NS_EM.length);
      if (prop == "signature")
        continue;

      var targets = aDs.GetTargets(aResource, arc, true);
      while (targets.hasMoreElements()) {
        var target = targets.getNext();
        if (target instanceof Ci.nsIRDFResource) {
          var item = aIndent + "<em:" + prop + ">\n";
          item += this.serializeResource(aDs, target, aIndent + this.INDENT);
          item += aIndent + "</em:" + prop + ">\n";
          items.push(item);
        }
        else if (target instanceof Ci.nsIRDFLiteral) {
          items.push(aIndent + "<em:" + prop + ">" +
                     this.escapeEntities(target.Value) + "</em:" + prop + ">\n");
        }
        else if (target instanceof Ci.nsIRDFInt) {
          items.push(aIndent + "<em:" + prop + " NC:parseType=\"Integer\">" +
                     target.Value + "</em:" + prop + ">\n");
        }
        else {
          throw Components.Exception("Cannot serialize unknown literal type");
        }
      }
    }
    items.sort();
    result += items.join("");
    return result;
  },

  /**
   * Recursively serializes an RDF resource and all resources it links to.
   * This will only output EM_NS properties and will ignore any em:signature
   * property.
   *
   * @param  aDs
   *         The RDF datasource
   * @param  aResource
   *         The RDF resource to serialize
   * @param  aIndent
   *         The current level of indent for pretty-printing. If undefined no
   *         indent will be added
   * @return a string containing the serialized resource.
   * @throws if the RDF data contains multiple references to the same resource.
   */
  serializeResource: function(aDs, aResource, aIndent) {
    if (this.resources.indexOf(aResource) != -1 ) {
      // We cannot output multiple references to the same resource.
      throw Components.Exception("Cannot serialize multiple references to " + aResource.Value);
    }
    if (aIndent === undefined)
      aIndent = "";

    this.resources.push(aResource);
    var container = null;
    var type = "Description";
    if (this.cUtils.IsSeq(aDs, aResource)) {
      type = "Seq";
      container = this.cUtils.MakeSeq(aDs, aResource);
    }
    else if (this.cUtils.IsAlt(aDs, aResource)) {
      type = "Alt";
      container = this.cUtils.MakeAlt(aDs, aResource);
    }
    else if (this.cUtils.IsBag(aDs, aResource)) {
      type = "Bag";
      container = this.cUtils.MakeBag(aDs, aResource);
    }

    var result = aIndent + "<RDF:" + type;
    if (!gRDF.IsAnonymousResource(aResource))
      result += " about=\"" + this.escapeEntities(aResource.ValueUTF8) + "\"";
    result += ">\n";

    if (container)
      result += this.serializeContainerItems(aDs, container, aIndent + this.INDENT);

    result += this.serializeResourceProperties(aDs, aResource, aIndent + this.INDENT);

    result += aIndent + "</RDF:" + type + ">\n";
    return result;
  }
}

/**
 * Sanitizes the update URL in an update item, as returned by
 * parseRDFManifest and parseJSONManifest. Ensures that:
 *
 * - The URL is secure, or secured by a strong enough hash.
 * - The security principal of the update manifest has permission to
 *   load the URL.
 *
 * @param aUpdate
 *        The update item to sanitize.
 * @param aRequest
 *        The XMLHttpRequest used to load the manifest.
 * @param aHashPattern
 *        The regular expression used to validate the update hash.
 * @param aHashString
 *        The human-readable string specifying which hash functions
 *        are accepted.
 */
function sanitizeUpdateURL(aUpdate, aRequest, aHashPattern, aHashString) {
  if (aUpdate.updateURL) {
    let scriptSecurity = Services.scriptSecurityManager;
    let principal = scriptSecurity.getChannelURIPrincipal(aRequest.channel);
    try {
      // This logs an error on failure, so no need to log it a second time
      scriptSecurity.checkLoadURIStrWithPrincipal(principal, aUpdate.updateURL,
                                                  scriptSecurity.DISALLOW_SCRIPT);
    } catch (e) {
      delete aUpdate.updateURL;
      return;
    }

    if (AddonManager.checkUpdateSecurity &&
        !aUpdate.updateURL.startsWith("https:") &&
        !aHashPattern.test(aUpdate.updateHash)) {
      logger.warn(`Update link ${aUpdate.updateURL} is not secure and is not verified ` +
                  `by a strong enough hash (needs to be ${aHashString}).`);
      delete aUpdate.updateURL;
      delete aUpdate.updateHash;
    }
  }
}

/**
 * Parses an RDF style update manifest into an array of update objects.
 *
 * @param  aId
 *         The ID of the add-on being checked for updates
 * @param  aUpdateKey
 *         An optional update key for the add-on
 * @param  aRequest
 *         The XMLHttpRequest that has retrieved the update manifest
 * @param  aManifestData
 *         The pre-parsed manifest, as a bare XML DOM document
 * @return an array of update objects
 * @throws if the update manifest is invalid in any way
 */
function parseRDFManifest(aId, aUpdateKey, aRequest, aManifestData) {
  if (aManifestData.documentElement.namespaceURI != PREFIX_NS_RDF) {
    throw Components.Exception("Update manifest had an unrecognised namespace: " +
                               aManifestData.documentElement.namespaceURI);
  }

  function EM_R(aProp) {
    return gRDF.GetResource(PREFIX_NS_EM + aProp);
  }

  function getValue(aLiteral) {
    if (aLiteral instanceof Ci.nsIRDFLiteral)
      return aLiteral.Value;
    if (aLiteral instanceof Ci.nsIRDFResource)
      return aLiteral.Value;
    if (aLiteral instanceof Ci.nsIRDFInt)
      return aLiteral.Value;
    return null;
  }

  function getProperty(aDs, aSource, aProperty) {
    return getValue(aDs.GetTarget(aSource, EM_R(aProperty), true));
  }

  function getBooleanProperty(aDs, aSource, aProperty) {
    let propValue = aDs.GetTarget(aSource, EM_R(aProperty), true);
    if (!propValue)
      return undefined;
    return getValue(propValue) == "true";
  }

  function getRequiredProperty(aDs, aSource, aProperty) {
    let value = getProperty(aDs, aSource, aProperty);
    if (!value)
      throw Components.Exception("Update manifest is missing a required " + aProperty + " property.");
    return value;
  }

  let rdfParser = Cc["@mozilla.org/rdf/xml-parser;1"].
                  createInstance(Ci.nsIRDFXMLParser);
  let ds = Cc["@mozilla.org/rdf/datasource;1?name=in-memory-datasource"].
           createInstance(Ci.nsIRDFDataSource);
  rdfParser.parseString(ds, aRequest.channel.URI, aRequest.responseText);

  // Differentiating between add-on types is deprecated
  let extensionRes = gRDF.GetResource(PREFIX_EXTENSION + aId);
  let themeRes = gRDF.GetResource(PREFIX_THEME + aId);
  let itemRes = gRDF.GetResource(PREFIX_ITEM + aId);
  let addonRes;
  if (ds.ArcLabelsOut(extensionRes).hasMoreElements())
    addonRes = extensionRes;
  else if (ds.ArcLabelsOut(themeRes).hasMoreElements())
    addonRes = themeRes;
  else
    addonRes = itemRes;

  // If we have an update key then the update manifest must be signed
  if (aUpdateKey) {
    let signature = getProperty(ds, addonRes, "signature");
    if (!signature)
      throw Components.Exception("Update manifest for " + aId + " does not contain a required signature");
    let serializer = new RDFSerializer();
    let updateString = null;

    try {
      updateString = serializer.serializeResource(ds, addonRes);
    }
    catch (e) {
      throw Components.Exception("Failed to generate signed string for " + aId + ". Serializer threw " + e,
                                 e.result);
    }

    let result = false;

    try {
      let verifier = Cc["@mozilla.org/security/datasignatureverifier;1"].
                     getService(Ci.nsIDataSignatureVerifier);
      result = verifier.verifyData(updateString, signature, aUpdateKey);
    }
    catch (e) {
      throw Components.Exception("The signature or updateKey for " + aId + " is malformed." +
                                 "Verifier threw " + e, e.result);
    }

    if (!result)
      throw Components.Exception("The signature for " + aId + " was not created by the add-on's updateKey");
  }

  let updates = ds.GetTarget(addonRes, EM_R("updates"), true);

  // A missing updates property doesn't count as a failure, just as no avialable
  // update information
  if (!updates) {
    logger.warn("Update manifest for " + aId + " did not contain an updates property");
    return [];
  }

  if (!(updates instanceof Ci.nsIRDFResource))
    throw Components.Exception("Missing updates property for " + addonRes.Value);

  let cu = Cc["@mozilla.org/rdf/container-utils;1"].
           getService(Ci.nsIRDFContainerUtils);
  if (!cu.IsContainer(ds, updates))
    throw Components.Exception("Updates property was not an RDF container");

  let results = [];
  let ctr = Cc["@mozilla.org/rdf/container;1"].
            createInstance(Ci.nsIRDFContainer);
  ctr.Init(ds, updates);
  let items = ctr.GetElements();
  while (items.hasMoreElements()) {
    let item = items.getNext().QueryInterface(Ci.nsIRDFResource);
    let version = getProperty(ds, item, "version");
    if (!version) {
      logger.warn("Update manifest is missing a required version property.");
      continue;
    }

    logger.debug("Found an update entry for " + aId + " version " + version);

    let targetApps = ds.GetTargets(item, EM_R("targetApplication"), true);
    while (targetApps.hasMoreElements()) {
      let targetApp = targetApps.getNext().QueryInterface(Ci.nsIRDFResource);

      let appEntry = {};
      try {
        appEntry.id = getRequiredProperty(ds, targetApp, "id");
        appEntry.minVersion = getRequiredProperty(ds, targetApp, "minVersion");
        appEntry.maxVersion = getRequiredProperty(ds, targetApp, "maxVersion");
      }
      catch (e) {
        logger.warn(e);
        continue;
      }

      let result = {
        id: aId,
        version: version,
        multiprocessCompatible: getBooleanProperty(ds, item, "multiprocessCompatible"),
        updateURL: getProperty(ds, targetApp, "updateLink"),
        updateHash: getProperty(ds, targetApp, "updateHash"),
        updateInfoURL: getProperty(ds, targetApp, "updateInfoURL"),
        strictCompatibility: !!getBooleanProperty(ds, targetApp, "strictCompatibility"),
        targetApplications: [appEntry]
      };

      // The JSON update protocol requires an SHA-2 hash. RDF still
      // supports SHA-1, for compatibility reasons.
      sanitizeUpdateURL(result, aRequest, /^sha/, "sha1 or stronger");

      results.push(result);
    }
  }
  return results;
}

/**
 * Parses an JSON update manifest into an array of update objects.
 *
 * @param  aId
 *         The ID of the add-on being checked for updates
 * @param  aUpdateKey
 *         An optional update key for the add-on
 * @param  aRequest
 *         The XMLHttpRequest that has retrieved the update manifest
 * @param  aManifestData
 *         The pre-parsed manifest, as a JSON object tree
 * @return an array of update objects
 * @throws if the update manifest is invalid in any way
 */
function parseJSONManifest(aId, aUpdateKey, aRequest, aManifestData) {
  if (aUpdateKey)
    throw Components.Exception("Update keys are not supported for JSON update manifests");

  let TYPE_CHECK = {
    "array": val => Array.isArray(val),
    "object": val => val && typeof val == "object" && !Array.isArray(val),
  };

  function getProperty(aObj, aProperty, aType, aDefault = undefined) {
    if (!(aProperty in aObj))
      return aDefault;

    let value = aObj[aProperty];

    let matchesType = aType in TYPE_CHECK ? TYPE_CHECK[aType](value) : typeof value == aType;
    if (!matchesType)
      throw Components.Exception(`Update manifest property '${aProperty}' has incorrect type (expected ${aType})`);

    return value;
  }

  function getRequiredProperty(aObj, aProperty, aType) {
    let value = getProperty(aObj, aProperty, aType);
    if (value === undefined)
      throw Components.Exception(`Update manifest is missing a required ${aProperty} property.`);
    return value;
  }

  let manifest = aManifestData;

  if (!TYPE_CHECK["object"](manifest))
    throw Components.Exception("Root element of update manifest must be a JSON object literal");

  // The set of add-ons this manifest has updates for
  let addons = getRequiredProperty(manifest, "addons", "object");

  // The entry for this particular add-on
  let addon = getProperty(addons, aId, "object");

  // A missing entry doesn't count as a failure, just as no avialable update
  // information
  if (!addon) {
    logger.warn("Update manifest did not contain an entry for " + aId);
    return [];
  }

  let appID = Services.appinfo.ID;
  let platformVersion = Services.appinfo.platformVersion;

  // The list of available updates
  let updates = getProperty(addon, "updates", "array", []);

  let results = [];

  for (let update of updates) {
    let version = getRequiredProperty(update, "version", "string");
    logger.debug(`Found an update entry for ${aId} version ${version}`);

    let applications = getRequiredProperty(update, "applications", "object");

    let app;
    let appEntry;

    if (appID in applications) {
      logger.debug("update.json: Native targetApplication");
      app = getProperty(applications, appID, "object");
      
      appEntry = {
        id: appID,
        minVersion: getRequiredProperty(app, "min_version", "string"),
        maxVersion: getRequiredProperty(app, "max_version", "string"),
      }
    }
#ifdef MOZ_PHOENIX_EXTENSIONS
    else if (FIREFOX_ID in applications) {
      logger.debug("update.json: Dual-GUID targetApplication");
      app = getProperty(applications, FIREFOX_ID, "object");

      appEntry = {
        id: FIREFOX_ID,
        minVersion: getRequiredProperty(app, "min_version", "string"),
        maxVersion: getRequiredProperty(app, "max_version", "string"),
      }
    }
#endif
    else if (TOOLKIT_ID in applications) {
      logger.debug("update.json: Toolkit targetApplication");
      app = getProperty(applications, TOOLKIT_ID, "object");
      
      appEntry = {
        id: TOOLKIT_ID,
        minVersion: getRequiredProperty(app, "min_version", "string"),
        maxVersion: getRequiredProperty(app, "max_version", "string"),
      }
    }
    else if ("gecko" in applications) {
      logger.debug("update.json: Mozilla Compatiblity Mode");
      app = getProperty(applications, "gecko", "object");

      appEntry = {
#ifdef MOZ_PHOENIX
        id: FIREFOX_ID,
        minVersion: getProperty(app, "strict_min_version", "string",
                                Services.prefs.getCharPref(PREF_EM_MIN_COMPAT_APP_VERSION)),
#else
        id: TOOLKIT_ID,
        minVersion: platformVersion,
#endif
#if defined(MOZ_PHOENIX) && defined(MOZ_PHOENIX_EXTENSIONS)
        maxVersion: FIREFOX_APPCOMPATVERSION,
#else
        maxVersion: '*',
#endif
      };
    }
    else {
      continue;
    }

    let result = {
      id: aId,
      version: version,
      multiprocessCompatible: getProperty(update, "multiprocess_compatible", "boolean", false),
      updateURL: getProperty(update, "update_link", "string"),
      updateHash: getProperty(update, "update_hash", "string"),
      updateInfoURL: getProperty(update, "update_info_url", "string"),
      strictCompatibility: getProperty(app, "strict_compatibility", "boolean", false),
      targetApplications: [appEntry],
    };

    // The JSON update protocol requires an SHA-2 hash. RDF still
    // supports SHA-1, for compatibility reasons.
    sanitizeUpdateURL(result, aRequest, /^sha(256|512):/, "sha256 or sha512");

    results.push(result);
  }
  return results;
}

/**
 * Starts downloading an update manifest and then passes it to an appropriate
 * parser to convert to an array of update objects
 *
 * @param  aId
 *         The ID of the add-on being checked for updates
 * @param  aUpdateKey
 *         An optional update key for the add-on
 * @param  aUrl
 *         The URL of the update manifest
 * @param  aObserver
 *         An observer to pass results to
 */
function UpdateParser(aId, aUpdateKey, aUrl, aObserver) {
  this.id = aId;
  this.updateKey = aUpdateKey;
  this.observer = aObserver;
  this.url = aUrl;

  let requireBuiltIn = true;
  try {
    requireBuiltIn = Services.prefs.getBoolPref(PREF_UPDATE_REQUIREBUILTINCERTS);
  }
  catch (e) {
  }

  logger.debug("Requesting " + aUrl);
  try {
    this.request = new ServiceRequest();
    this.request.open("GET", this.url, true);
    this.request.channel.notificationCallbacks = new CertUtils.BadCertHandler(!requireBuiltIn);
    this.request.channel.loadFlags |= Ci.nsIRequest.LOAD_BYPASS_CACHE;
    // Prevent the request from writing to cache.
    this.request.channel.loadFlags |= Ci.nsIRequest.INHIBIT_CACHING;
    this.request.overrideMimeType("text/plain");
    this.request.setRequestHeader("Moz-XPI-Update", "1", true);
    this.request.timeout = TIMEOUT;
    this.request.addEventListener("load", () => this.onLoad(), false);
    this.request.addEventListener("error", () => this.onError(), false);
    this.request.addEventListener("timeout", () => this.onTimeout(), false);
    this.request.send(null);
  }
  catch (e) {
    logger.error("Failed to request update manifest", e);
  }
}

UpdateParser.prototype = {
  id: null,
  updateKey: null,
  observer: null,
  request: null,
  url: null,

  /**
   * Called when the manifest has been successfully loaded.
   */
  onLoad: function() {
    let request = this.request;
    this.request = null;
    this._doneAt = new Error("place holder");

    let requireBuiltIn = true;
    try {
      requireBuiltIn = Services.prefs.getBoolPref(PREF_UPDATE_REQUIREBUILTINCERTS);
    }
    catch (e) {
    }

    try {
      CertUtils.checkCert(request.channel, !requireBuiltIn);
    }
    catch (e) {
      logger.warn("Request failed: " + this.url + " - " + e);
      this.notifyError(AddonUpdateChecker.ERROR_DOWNLOAD_ERROR);
      return;
    }

    if (!Components.isSuccessCode(request.status)) {
      logger.warn("Request failed: " + this.url + " - " + request.status);
      this.notifyError(AddonUpdateChecker.ERROR_DOWNLOAD_ERROR);
      return;
    }

    let channel = request.channel;
    if (channel instanceof Ci.nsIHttpChannel && !channel.requestSucceeded) {
      logger.warn("Request failed: " + this.url + " - " + channel.responseStatus +
           ": " + channel.responseStatusText);
      this.notifyError(AddonUpdateChecker.ERROR_DOWNLOAD_ERROR);
      return;
    }

    // Detect the manifest type by first attempting to parse it as
    // JSON, and falling back to parsing it as XML if that fails.
    let parser;
    try {
      try {
        let json = JSON.parse(request.responseText);

        parser = () => parseJSONManifest(this.id, this.updateKey, request, json);
      } catch (e) {
        if (!(e instanceof SyntaxError))
          throw e;
        let domParser = Cc["@mozilla.org/xmlextras/domparser;1"].createInstance(Ci.nsIDOMParser);
        let xml = domParser.parseFromString(request.responseText, "text/xml");

        if (xml.documentElement.namespaceURI == XMLURI_PARSE_ERROR)
          throw new Error("Update manifest was not valid XML or JSON");

        parser = () => parseRDFManifest(this.id, this.updateKey, request, xml);
      }
    } catch (e) {
      logger.warn("onUpdateCheckComplete failed to determine manifest type");
      this.notifyError(AddonUpdateChecker.ERROR_UNKNOWN_FORMAT);
      return;
    }

    let results;
    try {
      results = parser();
    }
    catch (e) {
      logger.warn("onUpdateCheckComplete failed to parse update manifest", e);
      this.notifyError(AddonUpdateChecker.ERROR_PARSE_ERROR);
      return;
    }

    if ("onUpdateCheckComplete" in this.observer) {
      try {
        this.observer.onUpdateCheckComplete(results);
      }
      catch (e) {
        logger.warn("onUpdateCheckComplete notification failed", e);
      }
    }
    else {
      logger.warn("onUpdateCheckComplete may not properly cancel", new Error("stack marker"));
    }
  },

  /**
   * Called when the request times out
   */
  onTimeout: function() {
    this.request = null;
    this._doneAt = new Error("Timed out");
    logger.warn("Request for " + this.url + " timed out");
    this.notifyError(AddonUpdateChecker.ERROR_TIMEOUT);
  },

  /**
   * Called when the manifest failed to load.
   */
  onError: function() {
    if (!Components.isSuccessCode(this.request.status)) {
      logger.warn("Request failed: " + this.url + " - " + this.request.status);
    }
    else if (this.request.channel instanceof Ci.nsIHttpChannel) {
      try {
        if (this.request.channel.requestSucceeded) {
          logger.warn("Request failed: " + this.url + " - " +
               this.request.channel.responseStatus + ": " +
               this.request.channel.responseStatusText);
        }
      }
      catch (e) {
        logger.warn("HTTP Request failed for an unknown reason");
      }
    }
    else {
      logger.warn("Request failed for an unknown reason");
    }

    this.request = null;
    this._doneAt = new Error("UP_onError");

    this.notifyError(AddonUpdateChecker.ERROR_DOWNLOAD_ERROR);
  },

  /**
   * Helper method to notify the observer that an error occured.
   */
  notifyError: function(aStatus) {
    if ("onUpdateCheckError" in this.observer) {
      try {
        this.observer.onUpdateCheckError(aStatus);
      }
      catch (e) {
        logger.warn("onUpdateCheckError notification failed", e);
      }
    }
  },

  /**
   * Called to cancel an in-progress update check.
   */
  cancel: function() {
    if (!this.request) {
      logger.error("Trying to cancel already-complete request", this._doneAt);
      return;
    }
    this.request.abort();
    this.request = null;
    this._doneAt = new Error("UP_cancel");
    this.notifyError(AddonUpdateChecker.ERROR_CANCELLED);
  }
};

/**
 * Tests if an update matches a version of the application or platform
 *
 * @param  aUpdate
 *         The available update
 * @param  aAppVersion
 *         The application version to use
 * @param  aPlatformVersion
 *         The platform version to use
 * @param  aIgnoreMaxVersion
 *         Ignore maxVersion when testing if an update matches. Optional.
 * @param  aIgnoreStrictCompat
 *         Ignore strictCompatibility when testing if an update matches. Optional.
 * @param  aCompatOverrides
 *         AddonCompatibilityOverride objects to match against. Optional.
 * @return true if the update is compatible with the application/platform
 */
function matchesVersions(aUpdate, aAppVersion, aPlatformVersion,
                         aIgnoreMaxVersion, aIgnoreStrictCompat,
                         aCompatOverrides) {
  if (aCompatOverrides) {
    let override = AddonRepository.findMatchingCompatOverride(aUpdate.version,
                                                              aCompatOverrides,
                                                              aAppVersion,
                                                              aPlatformVersion);
    if (override && override.type == "incompatible")
      return false;
  }

  if (aUpdate.strictCompatibility && !aIgnoreStrictCompat)
    aIgnoreMaxVersion = false;

  let result = false;
  for (let app of aUpdate.targetApplications) {
    if (app.id == Services.appinfo.ID) {
      return (Services.vc.compare(aAppVersion, app.minVersion) >= 0) &&
             (aIgnoreMaxVersion || (Services.vc.compare(aAppVersion, app.maxVersion) <= 0));
    }
#ifdef MOZ_PHOENIX_EXTENSIONS
    if (app.id == FIREFOX_ID) {
      return (Services.vc.compare(aAppVersion, app.minVersion) >= 0) &&
             (aIgnoreMaxVersion || (Services.vc.compare(aAppVersion, app.maxVersion) <= 0));
    }
#endif
    if (app.id == TOOLKIT_ID) {
      result = (Services.vc.compare(aPlatformVersion, app.minVersion) >= 0) &&
               (aIgnoreMaxVersion || (Services.vc.compare(aPlatformVersion, app.maxVersion) <= 0));
    }
  }
  return result;
}

this.AddonUpdateChecker = {
  // These must be kept in sync with AddonManager
  // The update check timed out
  ERROR_TIMEOUT: -1,
  // There was an error while downloading the update information.
  ERROR_DOWNLOAD_ERROR: -2,
  // The update information was malformed in some way.
  ERROR_PARSE_ERROR: -3,
  // The update information was not in any known format.
  ERROR_UNKNOWN_FORMAT: -4,
  // The update information was not correctly signed or there was an SSL error.
  ERROR_SECURITY_ERROR: -5,
  // The update was cancelled
  ERROR_CANCELLED: -6,

  /**
   * Retrieves the best matching compatibility update for the application from
   * a list of available update objects.
   *
   * @param  aUpdates
   *         An array of update objects
   * @param  aVersion
   *         The version of the add-on to get new compatibility information for
   * @param  aIgnoreCompatibility
   *         An optional parameter to get the first compatibility update that
   *         is compatible with any version of the application or toolkit
   * @param  aAppVersion
   *         The version of the application or null to use the current version
   * @param  aPlatformVersion
   *         The version of the platform or null to use the current version
   * @param  aIgnoreMaxVersion
   *         Ignore maxVersion when testing if an update matches. Optional.
   * @param  aIgnoreStrictCompat
   *         Ignore strictCompatibility when testing if an update matches. Optional.
   * @return an update object if one matches or null if not
   */
  getCompatibilityUpdate: function(aUpdates, aVersion, aIgnoreCompatibility,
                                   aAppVersion, aPlatformVersion,
                                   aIgnoreMaxVersion, aIgnoreStrictCompat) {
    if (!aAppVersion)
      aAppVersion = Services.appinfo.version;
    if (!aPlatformVersion)
      aPlatformVersion = Services.appinfo.platformVersion;

    for (let update of aUpdates) {
      if (Services.vc.compare(update.version, aVersion) == 0) {
        if (aIgnoreCompatibility) {
          for (let targetApp of update.targetApplications) {
            let id = targetApp.id;
#ifdef MOZ_PHOENIX_EXTENSIONS
            if (id == Services.appinfo.ID || id == FIREFOX_ID ||
                id == TOOLKIT_ID)
#else
            if (id == Services.appinfo.ID || id == TOOLKIT_ID)
#endif
              return update;
          }
        }
        else if (matchesVersions(update, aAppVersion, aPlatformVersion,
                                 aIgnoreMaxVersion, aIgnoreStrictCompat)) {
          return update;
        }
      }
    }
    return null;
  },

  /**
   * Returns the newest available update from a list of update objects.
   *
   * @param  aUpdates
   *         An array of update objects
   * @param  aAppVersion
   *         The version of the application or null to use the current version
   * @param  aPlatformVersion
   *         The version of the platform or null to use the current version
   * @param  aIgnoreMaxVersion
   *         When determining compatible updates, ignore maxVersion. Optional.
   * @param  aIgnoreStrictCompat
   *         When determining compatible updates, ignore strictCompatibility. Optional.
   * @param  aCompatOverrides
   *         Array of AddonCompatibilityOverride to take into account. Optional.
   * @return an update object if one matches or null if not
   */
  getNewestCompatibleUpdate: function(aUpdates, aAppVersion, aPlatformVersion,
                                      aIgnoreMaxVersion, aIgnoreStrictCompat,
                                      aCompatOverrides) {
    if (!aAppVersion)
      aAppVersion = Services.appinfo.version;
    if (!aPlatformVersion)
      aPlatformVersion = Services.appinfo.platformVersion;

    let blocklist = Cc["@mozilla.org/extensions/blocklist;1"].
                    getService(Ci.nsIBlocklistService);

    let newest = null;
    for (let update of aUpdates) {
      if (!update.updateURL)
        continue;
      let state = blocklist.getAddonBlocklistState(update, aAppVersion, aPlatformVersion);
      if (state != Ci.nsIBlocklistService.STATE_NOT_BLOCKED)
        continue;
      if ((newest == null || (Services.vc.compare(newest.version, update.version) < 0)) &&
          matchesVersions(update, aAppVersion, aPlatformVersion,
                          aIgnoreMaxVersion, aIgnoreStrictCompat,
                          aCompatOverrides)) {
        newest = update;
      }
    }
    return newest;
  },

  /**
   * Starts an update check.
   *
   * @param  aId
   *         The ID of the add-on being checked for updates
   * @param  aUpdateKey
   *         An optional update key for the add-on
   * @param  aUrl
   *         The URL of the add-on's update manifest
   * @param  aObserver
   *         An observer to notify of results
   * @return UpdateParser so that the caller can use UpdateParser.cancel() to shut
   *         down in-progress update requests
   */
  checkForUpdates: function(aId, aUpdateKey, aUrl, aObserver) {
    // Define an array of internally used IDs to NOT send to AUS such as the
    // Default Theme. Please keep this list in sync with:
    // toolkit/mozapps/extensions/AddonUpdateChecker.jsm
    let internalIDS = [
      '{972ce4c6-7e08-4474-a285-3208198ce6fd}',
      'modern@themes.mozilla.org'
    ];
    
    // If the ID is not in the array then go ahead and query AUS
    if (internalIDS.indexOf(aId) == -1) {
        return new UpdateParser(aId, aUpdateKey, aUrl, aObserver);
    }
  }
};