chrome/browser/extensions/permissions_updater.cc

   1 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #include "chrome/browser/extensions/permissions_updater.h"
   6
   7 #include "base/json/json_writer.h"
   8 #include "base/memory/ref_counted.h"
   9 #include "base/values.h"
  10 #include "chrome/browser/chrome_notification_types.h"
  11 #include "chrome/browser/extensions/api/permissions/permissions_api_helpers.h"
  12 #include "chrome/browser/extensions/extension_util.h"
  13 #include "chrome/browser/profiles/profile.h"
  14 #include "chrome/common/extensions/api/permissions.h"
  15 #include "content/public/browser/notification_observer.h"
  16 #include "content/public/browser/notification_registrar.h"
  17 #include "content/public/browser/notification_service.h"
  18 #include "content/public/browser/render_process_host.h"
  19 #include "extensions/browser/event_router.h"
  20 #include "extensions/browser/extension_prefs.h"
  21 #include "extensions/common/extension.h"
  22 #include "extensions/common/extension_messages.h"
  23 #include "extensions/common/manifest_handlers/permissions_parser.h"
  24 #include "extensions/common/permissions/permission_set.h"
  25 #include "extensions/common/permissions/permissions_data.h"
  26 #include "extensions/common/url_pattern.h"
  27 #include "extensions/common/url_pattern_set.h"
  28
  29 using content::RenderProcessHost;
  30 using extensions::permissions_api_helpers::PackPermissionSet;
  31
  32 namespace extensions {
  33
  34 namespace permissions = api::permissions;
  35
  36 namespace {
  37
  38 // Returns a set of single origin permissions from |permissions| that match
  39 // |bounds|. This is necessary for two reasons:
  40 //   a) single origin active permissions can get filtered out in
  41 //      GetBoundedActivePermissions because they are not recognized as a subset
  42 //      of all-host permissions
  43 //   b) active permissions that do not match any manifest permissions can
  44 //      exist if a manifest permission is dropped
  45 URLPatternSet FilterSingleOriginPermissions(const URLPatternSet& permissions,
  46                                             const URLPatternSet& bounds) {
  47   URLPatternSet single_origin_permissions;
  48   for (URLPatternSet::const_iterator iter = permissions.begin();
  49        iter != permissions.end();
  50        ++iter) {
  51     if (iter->MatchesSingleOrigin() &&
  52         bounds.MatchesURL(GURL(iter->GetAsString()))) {
  53       single_origin_permissions.AddPattern(*iter);
  54     }
  55   }
  56   return single_origin_permissions;
  57 }
  58
  59 // Returns a PermissionSet that has the active permissions of the extension,
  60 // bounded to its current manifest.
  61 scoped_refptr<const PermissionSet> GetBoundedActivePermissions(
  62     const Extension* extension,
  63     const scoped_refptr<const PermissionSet>& active_permissions) {
  64   // If the extension has used the optional permissions API, it will have a
  65   // custom set of active permissions defined in the extension prefs. Here,
  66   // we update the extension's active permissions based on the prefs.
  67   if (!active_permissions.get())
  68     return extension->permissions_data()->active_permissions();
  69
  70   scoped_refptr<const PermissionSet> required_permissions =
  71       PermissionsParser::GetRequiredPermissions(extension);
  72
  73   // We restrict the active permissions to be within the bounds defined in the
  74   // extension's manifest.
  75   //  a) active permissions must be a subset of optional + default permissions
  76   //  b) active permissions must contains all default permissions
  77   scoped_refptr<PermissionSet> total_permissions = PermissionSet::CreateUnion(
  78       required_permissions.get(),
  79       PermissionsParser::GetOptionalPermissions(extension).get());
  80
  81   // Make sure the active permissions contain no more than optional + default.
  82   scoped_refptr<PermissionSet> adjusted_active =
  83       PermissionSet::CreateIntersection(total_permissions.get(),
  84                                         active_permissions.get());
  85
  86   // Make sure the active permissions contain the default permissions.
  87   adjusted_active = PermissionSet::CreateUnion(required_permissions.get(),
  88                                                adjusted_active.get());
  89
  90   return adjusted_active;
  91 }
  92
  93 // Divvy up the |url patterns| between those we grant and those we do not. If
  94 // |withhold_permissions| is false (because the requisite feature is not
  95 // enabled), no permissions are withheld.
  96 void SegregateUrlPermissions(const URLPatternSet& url_patterns,
  97                              bool withhold_permissions,
  98                              URLPatternSet* granted,
  99                              URLPatternSet* withheld) {
 100   for (URLPatternSet::const_iterator iter = url_patterns.begin();
 101        iter != url_patterns.end();
 102        ++iter) {
 103     if (withhold_permissions && iter->ImpliesAllHosts())
 104       withheld->AddPattern(*iter);
 105     else
 106       granted->AddPattern(*iter);
 107   }
 108 }
 109
 110 }  // namespace
 111
 112 PermissionsUpdater::PermissionsUpdater(content::BrowserContext* browser_context)
 113     : browser_context_(browser_context), init_flag_(INIT_FLAG_NONE) {
 114 }
 115
 116 PermissionsUpdater::PermissionsUpdater(content::BrowserContext* browser_context,
 117                                        InitFlag init_flag)
 118     : browser_context_(browser_context), init_flag_(init_flag) {
 119 }
 120
 121 PermissionsUpdater::~PermissionsUpdater() {}
 122
 123 void PermissionsUpdater::AddPermissions(
 124     const Extension* extension, const PermissionSet* permissions) {
 125   scoped_refptr<const PermissionSet> existing(
 126       extension->permissions_data()->active_permissions());
 127   scoped_refptr<PermissionSet> total(
 128       PermissionSet::CreateUnion(existing.get(), permissions));
 129   scoped_refptr<PermissionSet> added(
 130       PermissionSet::CreateDifference(total.get(), existing.get()));
 131
 132   SetPermissions(extension, total, NULL);
 133
 134   // Update the granted permissions so we don't auto-disable the extension.
 135   GrantActivePermissions(extension);
 136
 137   NotifyPermissionsUpdated(ADDED, extension, added.get());
 138 }
 139
 140 void PermissionsUpdater::RemovePermissions(
 141     const Extension* extension, const PermissionSet* permissions) {
 142   scoped_refptr<const PermissionSet> existing(
 143       extension->permissions_data()->active_permissions());
 144   scoped_refptr<PermissionSet> total(
 145       PermissionSet::CreateDifference(existing.get(), permissions));
 146   scoped_refptr<PermissionSet> removed(
 147       PermissionSet::CreateDifference(existing.get(), total.get()));
 148
 149   // We update the active permissions, and not the granted permissions, because
 150   // the extension, not the user, removed the permissions. This allows the
 151   // extension to add them again without prompting the user.
 152   SetPermissions(extension, total, NULL);
 153
 154   NotifyPermissionsUpdated(REMOVED, extension, removed.get());
 155 }
 156
 157 void PermissionsUpdater::GrantActivePermissions(const Extension* extension) {
 158   CHECK(extension);
 159
 160   ExtensionPrefs::Get(browser_context_)->AddGrantedPermissions(
 161       extension->id(),
 162       extension->permissions_data()->active_permissions().get());
 163 }
 164
 165 void PermissionsUpdater::InitializePermissions(const Extension* extension) {
 166   scoped_refptr<const PermissionSet> active_permissions(NULL);
 167   scoped_refptr<const PermissionSet> bounded_active(NULL);
 168   // If |extension| is a transient dummy extension, we do not want to look for
 169   // it in preferences.
 170   if (init_flag_ & INIT_FLAG_TRANSIENT) {
 171     bounded_active = active_permissions =
 172         extension->permissions_data()->active_permissions();
 173   } else {
 174     active_permissions = ExtensionPrefs::Get(browser_context_)
 175                              ->GetActivePermissions(extension->id());
 176     bounded_active = GetBoundedActivePermissions(extension, active_permissions);
 177   }
 178
 179   // Determine whether or not to withhold host permissions.
 180   bool should_withhold_permissions = false;
 181   if (PermissionsData::ScriptsMayRequireActionForExtension(
 182           extension, bounded_active.get())) {
 183     should_withhold_permissions =
 184         init_flag_ & INIT_FLAG_TRANSIENT ?
 185             !util::DefaultAllowedScriptingOnAllUrls() :
 186             !util::AllowedScriptingOnAllUrls(extension->id(), browser_context_);
 187   }
 188
 189   URLPatternSet granted_explicit_hosts;
 190   URLPatternSet withheld_explicit_hosts;
 191   SegregateUrlPermissions(bounded_active->explicit_hosts(),
 192                           should_withhold_permissions,
 193                           &granted_explicit_hosts,
 194                           &withheld_explicit_hosts);
 195
 196   URLPatternSet granted_scriptable_hosts;
 197   URLPatternSet withheld_scriptable_hosts;
 198   SegregateUrlPermissions(bounded_active->scriptable_hosts(),
 199                           should_withhold_permissions,
 200                           &granted_scriptable_hosts,
 201                           &withheld_scriptable_hosts);
 202
 203   // After withholding permissions, add back any origins to the active set that
 204   // may have been lost during the set operations that would have dropped them.
 205   // For example, the union of <all_urls> and "example.com" is <all_urls>, so
 206   // we may lose "example.com". However, "example.com" is important once
 207   // <all_urls> is stripped during withholding.
 208   if (active_permissions.get()) {
 209     granted_explicit_hosts.AddPatterns(
 210         FilterSingleOriginPermissions(active_permissions->explicit_hosts(),
 211                                       bounded_active->explicit_hosts()));
 212     granted_scriptable_hosts.AddPatterns(
 213         FilterSingleOriginPermissions(active_permissions->scriptable_hosts(),
 214                                       bounded_active->scriptable_hosts()));
 215   }
 216
 217   bounded_active = new PermissionSet(bounded_active->apis(),
 218                                      bounded_active->manifest_permissions(),
 219                                      granted_explicit_hosts,
 220                                      granted_scriptable_hosts);
 221
 222   scoped_refptr<const PermissionSet> withheld =
 223       new PermissionSet(APIPermissionSet(),
 224                         ManifestPermissionSet(),
 225                         withheld_explicit_hosts,
 226                         withheld_scriptable_hosts);
 227   SetPermissions(extension, bounded_active, withheld);
 228 }
 229
 230 void PermissionsUpdater::WithholdImpliedAllHosts(const Extension* extension) {
 231   scoped_refptr<const PermissionSet> active =
 232       extension->permissions_data()->active_permissions();
 233   scoped_refptr<const PermissionSet> withheld =
 234       extension->permissions_data()->withheld_permissions();
 235
 236   URLPatternSet withheld_scriptable = withheld->scriptable_hosts();
 237   URLPatternSet active_scriptable;
 238   SegregateUrlPermissions(active->scriptable_hosts(),
 239                           true,  // withhold permissions
 240                           &active_scriptable,
 241                           &withheld_scriptable);
 242
 243   URLPatternSet withheld_explicit = withheld->explicit_hosts();
 244   URLPatternSet active_explicit;
 245   SegregateUrlPermissions(active->explicit_hosts(),
 246                           true,  // withhold permissions
 247                           &active_explicit,
 248                           &withheld_explicit);
 249
 250   URLPatternSet delta_explicit;
 251   URLPatternSet::CreateDifference(
 252       active->explicit_hosts(), active_explicit, &delta_explicit);
 253   URLPatternSet delta_scriptable;
 254   URLPatternSet::CreateDifference(
 255       active->scriptable_hosts(), active_scriptable, &delta_scriptable);
 256
 257   SetPermissions(extension,
 258                  new PermissionSet(active->apis(),
 259                                    active->manifest_permissions(),
 260                                    active_explicit,
 261                                    active_scriptable),
 262                  new PermissionSet(withheld->apis(),
 263                                    withheld->manifest_permissions(),
 264                                    withheld_explicit,
 265                                    withheld_scriptable));
 266
 267   scoped_refptr<const PermissionSet> delta(new PermissionSet(
 268       APIPermissionSet(),
 269       ManifestPermissionSet(),
 270       delta_explicit,
 271       delta_scriptable));
 272   NotifyPermissionsUpdated(REMOVED, extension, delta.get());
 273 }
 274
 275 void PermissionsUpdater::GrantWithheldImpliedAllHosts(
 276     const Extension* extension) {
 277   scoped_refptr<const PermissionSet> active =
 278       extension->permissions_data()->active_permissions();
 279   scoped_refptr<const PermissionSet> withheld =
 280       extension->permissions_data()->withheld_permissions();
 281
 282   // Move the all-hosts permission from withheld to active.
 283   // We can cheat a bit here since we know that the only host permission we
 284   // withhold is allhosts (or something similar enough to it), so we can just
 285   // grant all withheld host permissions.
 286   URLPatternSet explicit_hosts;
 287   URLPatternSet::CreateUnion(
 288       active->explicit_hosts(), withheld->explicit_hosts(), &explicit_hosts);
 289   URLPatternSet scriptable_hosts;
 290   URLPatternSet::CreateUnion(active->scriptable_hosts(),
 291                              withheld->scriptable_hosts(),
 292                              &scriptable_hosts);
 293
 294   URLPatternSet delta_explicit;
 295   URLPatternSet::CreateDifference(
 296       explicit_hosts, active->explicit_hosts(), &delta_explicit);
 297   URLPatternSet delta_scriptable;
 298   URLPatternSet::CreateDifference(
 299       scriptable_hosts, active->scriptable_hosts(), &delta_scriptable);
 300
 301   // Since we only withhold host permissions (so far), we know that withheld
 302   // permissions will be empty.
 303   SetPermissions(extension,
 304                  new PermissionSet(active->apis(),
 305                                    active->manifest_permissions(),
 306                                    explicit_hosts,
 307                                    scriptable_hosts),
 308                  new PermissionSet());
 309
 310   scoped_refptr<const PermissionSet> delta(new PermissionSet(
 311       APIPermissionSet(),
 312       ManifestPermissionSet(),
 313       delta_explicit,
 314       delta_scriptable));
 315   NotifyPermissionsUpdated(ADDED, extension, delta.get());
 316 }
 317
 318 void PermissionsUpdater::SetPermissions(
 319     const Extension* extension,
 320     const scoped_refptr<const PermissionSet>& active,
 321     scoped_refptr<const PermissionSet> withheld) {
 322   withheld = withheld.get() ? withheld
 323                  : extension->permissions_data()->withheld_permissions();
 324   extension->permissions_data()->SetPermissions(active, withheld);
 325   if ((init_flag_ & INIT_FLAG_TRANSIENT) == 0) {
 326     ExtensionPrefs::Get(browser_context_)
 327         ->SetActivePermissions(extension->id(), active.get());
 328   }
 329 }
 330
 331 void PermissionsUpdater::DispatchEvent(
 332     const std::string& extension_id,
 333     events::HistogramValue histogram_value,
 334     const char* event_name,
 335     const PermissionSet* changed_permissions) {
 336   EventRouter* event_router = EventRouter::Get(browser_context_);
 337   if (!event_router)
 338     return;
 339
 340   scoped_ptr<base::ListValue> value(new base::ListValue());
 341   scoped_ptr<api::permissions::Permissions> permissions =
 342       PackPermissionSet(changed_permissions);
 343   value->Append(permissions->ToValue().release());
 344   scoped_ptr<Event> event(new Event(histogram_value, event_name, value.Pass()));
 345   event->restrict_to_browser_context = browser_context_;
 346   event_router->DispatchEventToExtension(extension_id, event.Pass());
 347 }
 348
 349 void PermissionsUpdater::NotifyPermissionsUpdated(
 350     EventType event_type,
 351     const Extension* extension,
 352     const PermissionSet* changed) {
 353   DCHECK((init_flag_ & INIT_FLAG_TRANSIENT) == 0);
 354   if (!changed || changed->IsEmpty())
 355     return;
 356
 357   UpdatedExtensionPermissionsInfo::Reason reason;
 358   events::HistogramValue histogram_value;
 359   const char* event_name = NULL;
 360
 361   if (event_type == REMOVED) {
 362     reason = UpdatedExtensionPermissionsInfo::REMOVED;
 363     histogram_value = events::PERMISSIONS_ON_REMOVED;
 364     event_name = permissions::OnRemoved::kEventName;
 365   } else {
 366     CHECK_EQ(ADDED, event_type);
 367     reason = UpdatedExtensionPermissionsInfo::ADDED;
 368     histogram_value = events::PERMISSIONS_ON_ADDED;
 369     event_name = permissions::OnAdded::kEventName;
 370   }
 371
 372   // Notify other APIs or interested parties.
 373   UpdatedExtensionPermissionsInfo info = UpdatedExtensionPermissionsInfo(
 374       extension, changed, reason);
 375   Profile* profile = Profile::FromBrowserContext(browser_context_);
 376   content::NotificationService::current()->Notify(
 377       extensions::NOTIFICATION_EXTENSION_PERMISSIONS_UPDATED,
 378       content::Source<Profile>(profile),
 379       content::Details<UpdatedExtensionPermissionsInfo>(&info));
 380
 381   ExtensionMsg_UpdatePermissions_Params params;
 382   params.extension_id = extension->id();
 383   params.active_permissions = ExtensionMsg_PermissionSetStruct(
 384       *extension->permissions_data()->active_permissions());
 385   params.withheld_permissions = ExtensionMsg_PermissionSetStruct(
 386       *extension->permissions_data()->withheld_permissions());
 387
 388   // Send the new permissions to the renderers.
 389   for (RenderProcessHost::iterator i(RenderProcessHost::AllHostsIterator());
 390        !i.IsAtEnd(); i.Advance()) {
 391     RenderProcessHost* host = i.GetCurrentValue();
 392     if (profile->IsSameProfile(
 393             Profile::FromBrowserContext(host->GetBrowserContext()))) {
 394       host->Send(new ExtensionMsg_UpdatePermissions(params));
 395     }
 396   }
 397
 398   // Trigger the onAdded and onRemoved events in the extension.
 399   DispatchEvent(extension->id(), histogram_value, event_name, changed);
 400 }
 401
 402 }  // namespace extensions