| // Copyright 2014 The Chromium Authors. All rights reserved. |
| // Use of this source code is governed by a BSD-style license that can be |
| // found in the LICENSE file. |
| |
| #include "extensions/common/features/simple_feature.h" |
| |
| #include <algorithm> |
| #include <map> |
| #include <vector> |
| |
| #include "base/bind.h" |
| #include "base/command_line.h" |
| #include "base/macros.h" |
| #include "base/sha1.h" |
| #include "base/stl_util.h" |
| #include "base/strings/string_number_conversions.h" |
| #include "base/strings/string_util.h" |
| #include "base/strings/stringprintf.h" |
| #include "components/crx_file/id_util.h" |
| #include "extensions/common/extension_api.h" |
| #include "extensions/common/features/feature_provider.h" |
| #include "extensions/common/features/feature_util.h" |
| #include "extensions/common/switches.h" |
| |
| using crx_file::id_util::HashedIdInHex; |
| |
| namespace extensions { |
| |
| namespace { |
| |
| // A singleton copy of the --whitelisted-extension-id so that we don't need to |
| // copy it from the CommandLine each time. |
| std::string* g_whitelisted_extension_id = NULL; |
| |
| Feature::Availability IsAvailableToManifestForBind( |
| const std::string& extension_id, |
| Manifest::Type type, |
| Manifest::Location location, |
| int manifest_version, |
| Feature::Platform platform, |
| const Feature* feature) { |
| return feature->IsAvailableToManifest( |
| extension_id, type, location, manifest_version, platform); |
| } |
| |
| Feature::Availability IsAvailableToContextForBind(const Extension* extension, |
| Feature::Context context, |
| const GURL& url, |
| Feature::Platform platform, |
| const Feature* feature) { |
| return feature->IsAvailableToContext(extension, context, url, platform); |
| } |
| |
| // TODO(aa): Can we replace all this manual parsing with JSON schema stuff? |
| |
| void ParseVector(const base::Value* value, |
| std::vector<std::string>* vector) { |
| const base::ListValue* list_value = NULL; |
| if (!value->GetAsList(&list_value)) |
| return; |
| |
| vector->clear(); |
| size_t list_size = list_value->GetSize(); |
| vector->reserve(list_size); |
| for (size_t i = 0; i < list_size; ++i) { |
| std::string str_val; |
| CHECK(list_value->GetString(i, &str_val)); |
| vector->push_back(str_val); |
| } |
| std::sort(vector->begin(), vector->end()); |
| } |
| |
| template<typename T> |
| void ParseEnum(const std::string& string_value, |
| T* enum_value, |
| const std::map<std::string, T>& mapping) { |
| const auto& iter = mapping.find(string_value); |
| if (iter == mapping.end()) |
| CRASH_WITH_MINIDUMP("Enum value not found: " + string_value); |
| *enum_value = iter->second; |
| } |
| |
| template<typename T> |
| void ParseEnum(const base::DictionaryValue* value, |
| const std::string& property, |
| T* enum_value, |
| const std::map<std::string, T>& mapping) { |
| std::string string_value; |
| if (!value->GetString(property, &string_value)) |
| return; |
| |
| ParseEnum(string_value, enum_value, mapping); |
| } |
| |
| template<typename T> |
| void ParseEnumVector(const base::Value* value, |
| std::vector<T>* enum_vector, |
| const std::map<std::string, T>& mapping) { |
| enum_vector->clear(); |
| std::string property_string; |
| if (value->GetAsString(&property_string)) { |
| if (property_string == "all") { |
| enum_vector->reserve(mapping.size()); |
| for (const auto& it : mapping) |
| enum_vector->push_back(it.second); |
| } |
| std::sort(enum_vector->begin(), enum_vector->end()); |
| return; |
| } |
| |
| std::vector<std::string> string_vector; |
| ParseVector(value, &string_vector); |
| enum_vector->reserve(string_vector.size()); |
| for (const auto& str : string_vector) { |
| T enum_value = static_cast<T>(0); |
| ParseEnum(str, &enum_value, mapping); |
| enum_vector->push_back(enum_value); |
| } |
| std::sort(enum_vector->begin(), enum_vector->end()); |
| } |
| |
| void ParseURLPatterns(const base::DictionaryValue* value, |
| const std::string& key, |
| URLPatternSet* set) { |
| const base::ListValue* matches = NULL; |
| if (value->GetList(key, &matches)) { |
| set->ClearPatterns(); |
| for (size_t i = 0; i < matches->GetSize(); ++i) { |
| std::string pattern; |
| CHECK(matches->GetString(i, &pattern)); |
| set->AddPattern(URLPattern(URLPattern::SCHEME_ALL, pattern)); |
| } |
| } |
| } |
| |
| // Gets a human-readable name for the given extension type, suitable for giving |
| // to developers in an error message. |
| std::string GetDisplayName(Manifest::Type type) { |
| switch (type) { |
| case Manifest::TYPE_UNKNOWN: |
| return "unknown"; |
| case Manifest::TYPE_EXTENSION: |
| return "extension"; |
| case Manifest::TYPE_HOSTED_APP: |
| return "hosted app"; |
| case Manifest::TYPE_LEGACY_PACKAGED_APP: |
| return "legacy packaged app"; |
| case Manifest::TYPE_PLATFORM_APP: |
| return "packaged app"; |
| case Manifest::TYPE_THEME: |
| return "theme"; |
| case Manifest::TYPE_USER_SCRIPT: |
| return "user script"; |
| case Manifest::TYPE_SHARED_MODULE: |
| return "shared module"; |
| case Manifest::NUM_LOAD_TYPES: |
| NOTREACHED(); |
| } |
| NOTREACHED(); |
| return ""; |
| } |
| |
| // Gets a human-readable name for the given context type, suitable for giving |
| // to developers in an error message. |
| std::string GetDisplayName(Feature::Context context) { |
| switch (context) { |
| case Feature::UNSPECIFIED_CONTEXT: |
| return "unknown"; |
| case Feature::BLESSED_EXTENSION_CONTEXT: |
| // "privileged" is vague but hopefully the developer will understand that |
| // means background or app window. |
| return "privileged page"; |
| case Feature::UNBLESSED_EXTENSION_CONTEXT: |
| // "iframe" is a bit of a lie/oversimplification, but that's the most |
| // common unblessed context. |
| return "extension iframe"; |
| case Feature::CONTENT_SCRIPT_CONTEXT: |
| return "content script"; |
| case Feature::WEB_PAGE_CONTEXT: |
| return "web page"; |
| case Feature::BLESSED_WEB_PAGE_CONTEXT: |
| return "hosted app"; |
| case Feature::WEBUI_CONTEXT: |
| return "webui"; |
| case Feature::SERVICE_WORKER_CONTEXT: |
| return "service worker"; |
| } |
| NOTREACHED(); |
| return ""; |
| } |
| |
| // Gets a human-readable list of the display names (pluralized, comma separated |
| // with the "and" in the correct place) for each of |enum_types|. |
| template <typename EnumType> |
| std::string ListDisplayNames(const std::vector<EnumType>& enum_types) { |
| std::string display_name_list; |
| for (size_t i = 0; i < enum_types.size(); ++i) { |
| // Pluralize type name. |
| display_name_list += GetDisplayName(enum_types[i]) + "s"; |
| // Comma-separate entries, with an Oxford comma if there is more than 2 |
| // total entries. |
| if (enum_types.size() > 2) { |
| if (i < enum_types.size() - 2) |
| display_name_list += ", "; |
| else if (i == enum_types.size() - 2) |
| display_name_list += ", and "; |
| } else if (enum_types.size() == 2 && i == 0) { |
| display_name_list += " and "; |
| } |
| } |
| return display_name_list; |
| } |
| |
| bool IsCommandLineSwitchEnabled(const std::string& switch_name) { |
| base::CommandLine* command_line = base::CommandLine::ForCurrentProcess(); |
| if (command_line->HasSwitch(switch_name + "=1")) |
| return true; |
| if (command_line->HasSwitch(std::string("enable-") + switch_name)) |
| return true; |
| return false; |
| } |
| |
| bool IsWhitelistedForTest(const std::string& extension_id) { |
| // TODO(jackhou): Delete the commandline whitelisting mechanism. |
| // Since it is only used it tests, ideally it should not be set via the |
| // commandline. At the moment the commandline is used as a mechanism to pass |
| // the id to the renderer process. |
| if (!g_whitelisted_extension_id) { |
| g_whitelisted_extension_id = new std::string( |
| base::CommandLine::ForCurrentProcess()->GetSwitchValueASCII( |
| switches::kWhitelistedExtensionID)); |
| } |
| return !g_whitelisted_extension_id->empty() && |
| *g_whitelisted_extension_id == extension_id; |
| } |
| |
| } // namespace |
| |
| SimpleFeature::ScopedWhitelistForTest::ScopedWhitelistForTest( |
| const std::string& id) |
| : previous_id_(g_whitelisted_extension_id) { |
| g_whitelisted_extension_id = new std::string(id); |
| } |
| |
| SimpleFeature::ScopedWhitelistForTest::~ScopedWhitelistForTest() { |
| delete g_whitelisted_extension_id; |
| g_whitelisted_extension_id = previous_id_; |
| } |
| |
| struct SimpleFeature::Mappings { |
| Mappings() { |
| extension_types["extension"] = Manifest::TYPE_EXTENSION; |
| extension_types["theme"] = Manifest::TYPE_THEME; |
| extension_types["legacy_packaged_app"] = Manifest::TYPE_LEGACY_PACKAGED_APP; |
| extension_types["hosted_app"] = Manifest::TYPE_HOSTED_APP; |
| extension_types["platform_app"] = Manifest::TYPE_PLATFORM_APP; |
| extension_types["shared_module"] = Manifest::TYPE_SHARED_MODULE; |
| |
| contexts["blessed_extension"] = Feature::BLESSED_EXTENSION_CONTEXT; |
| contexts["unblessed_extension"] = Feature::UNBLESSED_EXTENSION_CONTEXT; |
| contexts["content_script"] = Feature::CONTENT_SCRIPT_CONTEXT; |
| contexts["web_page"] = Feature::WEB_PAGE_CONTEXT; |
| contexts["blessed_web_page"] = Feature::BLESSED_WEB_PAGE_CONTEXT; |
| contexts["webui"] = Feature::WEBUI_CONTEXT; |
| |
| locations["component"] = SimpleFeature::COMPONENT_LOCATION; |
| locations["external_component"] = |
| SimpleFeature::EXTERNAL_COMPONENT_LOCATION; |
| locations["policy"] = SimpleFeature::POLICY_LOCATION; |
| |
| platforms["chromeos"] = Feature::CHROMEOS_PLATFORM; |
| platforms["linux"] = Feature::LINUX_PLATFORM; |
| platforms["mac"] = Feature::MACOSX_PLATFORM; |
| platforms["win"] = Feature::WIN_PLATFORM; |
| } |
| |
| std::map<std::string, Manifest::Type> extension_types; |
| std::map<std::string, Feature::Context> contexts; |
| std::map<std::string, SimpleFeature::Location> locations; |
| std::map<std::string, Feature::Platform> platforms; |
| }; |
| |
| SimpleFeature::SimpleFeature() |
| : location_(UNSPECIFIED_LOCATION), |
| min_manifest_version_(0), |
| max_manifest_version_(0), |
| component_extensions_auto_granted_(true) {} |
| |
| SimpleFeature::~SimpleFeature() {} |
| |
| bool SimpleFeature::HasDependencies() const { |
| return !dependencies_.empty(); |
| } |
| |
| void SimpleFeature::AddFilter(scoped_ptr<SimpleFeatureFilter> filter) { |
| filters_.push_back(filter.Pass()); |
| } |
| |
| std::string SimpleFeature::Parse(const base::DictionaryValue* dictionary) { |
| static base::LazyInstance<SimpleFeature::Mappings> mappings = |
| LAZY_INSTANCE_INITIALIZER; |
| |
| no_parent_ = false; |
| for (base::DictionaryValue::Iterator it(*dictionary); |
| !it.IsAtEnd(); |
| it.Advance()) { |
| std::string key = it.key(); |
| const base::Value* value = &it.value(); |
| if (key == "matches") { |
| ParseURLPatterns(dictionary, "matches", &matches_); |
| } else if (key == "blacklist") { |
| ParseVector(value, &blacklist_); |
| } else if (key == "whitelist") { |
| ParseVector(value, &whitelist_); |
| } else if (key == "dependencies") { |
| ParseVector(value, &dependencies_); |
| } else if (key == "extension_types") { |
| ParseEnumVector<Manifest::Type>(value, &extension_types_, |
| mappings.Get().extension_types); |
| } else if (key == "contexts") { |
| ParseEnumVector<Context>(value, &contexts_, |
| mappings.Get().contexts); |
| } else if (key == "location") { |
| ParseEnum<Location>(dictionary, "location", &location_, |
| mappings.Get().locations); |
| } else if (key == "platforms") { |
| ParseEnumVector<Platform>(value, &platforms_, |
| mappings.Get().platforms); |
| } else if (key == "min_manifest_version") { |
| dictionary->GetInteger("min_manifest_version", &min_manifest_version_); |
| } else if (key == "max_manifest_version") { |
| dictionary->GetInteger("max_manifest_version", &max_manifest_version_); |
| } else if (key == "noparent") { |
| dictionary->GetBoolean("noparent", &no_parent_); |
| } else if (key == "component_extensions_auto_granted") { |
| dictionary->GetBoolean("component_extensions_auto_granted", |
| &component_extensions_auto_granted_); |
| } else if (key == "command_line_switch") { |
| dictionary->GetString("command_line_switch", &command_line_switch_); |
| } |
| } |
| |
| // NOTE: ideally we'd sanity check that "matches" can be specified if and |
| // only if there's a "web_page" or "webui" context, but without |
| // (Simple)Features being aware of their own heirarchy this is impossible. |
| // |
| // For example, we might have feature "foo" available to "web_page" context |
| // and "matches" google.com/*. Then a sub-feature "foo.bar" might override |
| // "matches" to be chromium.org/*. That sub-feature doesn't need to specify |
| // "web_page" context because it's inherited, but we don't know that here. |
| |
| std::string result; |
| for (const auto& filter : filters_) { |
| result = filter->Parse(dictionary); |
| if (!result.empty()) |
| break; |
| } |
| |
| return result; |
| } |
| |
| Feature::Availability SimpleFeature::IsAvailableToManifest( |
| const std::string& extension_id, |
| Manifest::Type type, |
| Manifest::Location location, |
| int manifest_version, |
| Platform platform) const { |
| // Check extension type first to avoid granting platform app permissions |
| // to component extensions. |
| // HACK(kalman): user script -> extension. Solve this in a more generic way |
| // when we compile feature files. |
| Manifest::Type type_to_check = (type == Manifest::TYPE_USER_SCRIPT) ? |
| Manifest::TYPE_EXTENSION : type; |
| if (!extension_types_.empty() && |
| !ContainsValue(extension_types_, type_to_check)) { |
| return CreateAvailability(INVALID_TYPE, type); |
| } |
| |
| if (IsIdInBlacklist(extension_id)) |
| return CreateAvailability(FOUND_IN_BLACKLIST, type); |
| |
| // TODO(benwells): don't grant all component extensions. |
| // See http://crbug.com/370375 for more details. |
| // Component extensions can access any feature. |
| // NOTE: Deliberately does not match EXTERNAL_COMPONENT. |
| if (component_extensions_auto_granted_ && location == Manifest::COMPONENT) |
| return CreateAvailability(IS_AVAILABLE, type); |
| |
| if (!whitelist_.empty() && !IsIdInWhitelist(extension_id) && |
| !IsWhitelistedForTest(extension_id)) { |
| return CreateAvailability(NOT_FOUND_IN_WHITELIST, type); |
| } |
| |
| if (!MatchesManifestLocation(location)) |
| return CreateAvailability(INVALID_LOCATION, type); |
| |
| if (!platforms_.empty() && !ContainsValue(platforms_, platform)) |
| return CreateAvailability(INVALID_PLATFORM, type); |
| |
| if (min_manifest_version_ != 0 && manifest_version < min_manifest_version_) |
| return CreateAvailability(INVALID_MIN_MANIFEST_VERSION, type); |
| |
| if (max_manifest_version_ != 0 && manifest_version > max_manifest_version_) |
| return CreateAvailability(INVALID_MAX_MANIFEST_VERSION, type); |
| |
| if (!command_line_switch_.empty() && |
| !IsCommandLineSwitchEnabled(command_line_switch_)) { |
| return CreateAvailability(MISSING_COMMAND_LINE_SWITCH, type); |
| } |
| |
| for (const auto& filter : filters_) { |
| Availability availability = filter->IsAvailableToManifest( |
| extension_id, type, location, manifest_version, platform); |
| if (!availability.is_available()) |
| return availability; |
| } |
| |
| return CheckDependencies(base::Bind(&IsAvailableToManifestForBind, |
| extension_id, |
| type, |
| location, |
| manifest_version, |
| platform)); |
| } |
| |
| Feature::Availability SimpleFeature::IsAvailableToContext( |
| const Extension* extension, |
| SimpleFeature::Context context, |
| const GURL& url, |
| SimpleFeature::Platform platform) const { |
| if (extension) { |
| Availability result = IsAvailableToManifest(extension->id(), |
| extension->GetType(), |
| extension->location(), |
| extension->manifest_version(), |
| platform); |
| if (!result.is_available()) |
| return result; |
| } |
| |
| if (!contexts_.empty() && !ContainsValue(contexts_, context)) |
| return CreateAvailability(INVALID_CONTEXT, context); |
| |
| // TODO(kalman): Consider checking |matches_| regardless of context type. |
| // Fewer surprises, and if the feature configuration wants to isolate |
| // "matches" from say "blessed_extension" then they can use complex features. |
| if ((context == WEB_PAGE_CONTEXT || context == WEBUI_CONTEXT) && |
| !matches_.MatchesURL(url)) { |
| return CreateAvailability(INVALID_URL, url); |
| } |
| |
| for (const auto& filter : filters_) { |
| Availability availability = |
| filter->IsAvailableToContext(extension, context, url, platform); |
| if (!availability.is_available()) |
| return availability; |
| } |
| |
| // TODO(kalman): Assert that if the context was a webpage or WebUI context |
| // then at some point a "matches" restriction was checked. |
| return CheckDependencies(base::Bind( |
| &IsAvailableToContextForBind, extension, context, url, platform)); |
| } |
| |
| std::string SimpleFeature::GetAvailabilityMessage( |
| AvailabilityResult result, |
| Manifest::Type type, |
| const GURL& url, |
| Context context) const { |
| switch (result) { |
| case IS_AVAILABLE: |
| return std::string(); |
| case NOT_FOUND_IN_WHITELIST: |
| case FOUND_IN_BLACKLIST: |
| return base::StringPrintf( |
| "'%s' is not allowed for specified extension ID.", |
| name().c_str()); |
| case INVALID_URL: |
| return base::StringPrintf("'%s' is not allowed on %s.", |
| name().c_str(), url.spec().c_str()); |
| case INVALID_TYPE: |
| return base::StringPrintf( |
| "'%s' is only allowed for %s, but this is a %s.", |
| name().c_str(), |
| ListDisplayNames(std::vector<Manifest::Type>( |
| extension_types_.begin(), extension_types_.end())).c_str(), |
| GetDisplayName(type).c_str()); |
| case INVALID_CONTEXT: |
| return base::StringPrintf( |
| "'%s' is only allowed to run in %s, but this is a %s", |
| name().c_str(), |
| ListDisplayNames(std::vector<Context>( |
| contexts_.begin(), contexts_.end())).c_str(), |
| GetDisplayName(context).c_str()); |
| case INVALID_LOCATION: |
| return base::StringPrintf( |
| "'%s' is not allowed for specified install location.", |
| name().c_str()); |
| case INVALID_PLATFORM: |
| return base::StringPrintf( |
| "'%s' is not allowed for specified platform.", |
| name().c_str()); |
| case INVALID_MIN_MANIFEST_VERSION: |
| return base::StringPrintf( |
| "'%s' requires manifest version of at least %d.", |
| name().c_str(), |
| min_manifest_version_); |
| case INVALID_MAX_MANIFEST_VERSION: |
| return base::StringPrintf( |
| "'%s' requires manifest version of %d or lower.", |
| name().c_str(), |
| max_manifest_version_); |
| case NOT_PRESENT: |
| return base::StringPrintf( |
| "'%s' requires a different Feature that is not present.", |
| name().c_str()); |
| case UNSUPPORTED_CHANNEL: |
| return base::StringPrintf( |
| "'%s' is unsupported in this version of the platform.", |
| name().c_str()); |
| case MISSING_COMMAND_LINE_SWITCH: |
| return base::StringPrintf( |
| "'%s' requires the '%s' command line switch to be enabled.", |
| name().c_str(), command_line_switch_.c_str()); |
| } |
| |
| NOTREACHED(); |
| return std::string(); |
| } |
| |
| Feature::Availability SimpleFeature::CreateAvailability( |
| AvailabilityResult result) const { |
| return Availability( |
| result, GetAvailabilityMessage(result, Manifest::TYPE_UNKNOWN, GURL(), |
| UNSPECIFIED_CONTEXT)); |
| } |
| |
| Feature::Availability SimpleFeature::CreateAvailability( |
| AvailabilityResult result, Manifest::Type type) const { |
| return Availability(result, GetAvailabilityMessage(result, type, GURL(), |
| UNSPECIFIED_CONTEXT)); |
| } |
| |
| Feature::Availability SimpleFeature::CreateAvailability( |
| AvailabilityResult result, |
| const GURL& url) const { |
| return Availability( |
| result, GetAvailabilityMessage(result, Manifest::TYPE_UNKNOWN, url, |
| UNSPECIFIED_CONTEXT)); |
| } |
| |
| Feature::Availability SimpleFeature::CreateAvailability( |
| AvailabilityResult result, |
| Context context) const { |
| return Availability( |
| result, GetAvailabilityMessage(result, Manifest::TYPE_UNKNOWN, GURL(), |
| context)); |
| } |
| |
| bool SimpleFeature::IsInternal() const { |
| return false; |
| } |
| |
| bool SimpleFeature::IsIdInBlacklist(const std::string& extension_id) const { |
| return IsIdInList(extension_id, blacklist_); |
| } |
| |
| bool SimpleFeature::IsIdInWhitelist(const std::string& extension_id) const { |
| return IsIdInList(extension_id, whitelist_); |
| } |
| |
| // static |
| bool SimpleFeature::IsIdInArray(const std::string& extension_id, |
| const char* const array[], |
| size_t array_length) { |
| if (!IsValidExtensionId(extension_id)) |
| return false; |
| |
| const char* const* start = array; |
| const char* const* end = array + array_length; |
| |
| return ((std::find(start, end, extension_id) != end) || |
| (std::find(start, end, HashedIdInHex(extension_id)) != end)); |
| } |
| |
| // static |
| bool SimpleFeature::IsIdInList(const std::string& extension_id, |
| const std::vector<std::string>& list) { |
| if (!IsValidExtensionId(extension_id)) |
| return false; |
| |
| return (ContainsValue(list, extension_id) || |
| ContainsValue(list, HashedIdInHex(extension_id))); |
| } |
| |
| bool SimpleFeature::MatchesManifestLocation( |
| Manifest::Location manifest_location) const { |
| switch (location_) { |
| case SimpleFeature::UNSPECIFIED_LOCATION: |
| return true; |
| case SimpleFeature::COMPONENT_LOCATION: |
| return manifest_location == Manifest::COMPONENT; |
| case SimpleFeature::EXTERNAL_COMPONENT_LOCATION: |
| return manifest_location == Manifest::EXTERNAL_COMPONENT; |
| case SimpleFeature::POLICY_LOCATION: |
| return manifest_location == Manifest::EXTERNAL_POLICY || |
| manifest_location == Manifest::EXTERNAL_POLICY_DOWNLOAD; |
| } |
| NOTREACHED(); |
| return false; |
| } |
| |
| Feature::Availability SimpleFeature::CheckDependencies( |
| const base::Callback<Availability(const Feature*)>& checker) const { |
| for (const auto& dep_name : dependencies_) { |
| Feature* dependency = |
| ExtensionAPI::GetSharedInstance()->GetFeatureDependency(dep_name); |
| if (!dependency) |
| return CreateAvailability(NOT_PRESENT); |
| Availability dependency_availability = checker.Run(dependency); |
| if (!dependency_availability.is_available()) |
| return dependency_availability; |
| } |
| return CreateAvailability(IS_AVAILABLE); |
| } |
| |
| // static |
| bool SimpleFeature::IsValidExtensionId(const std::string& extension_id) { |
| // Belt-and-suspenders philosophy here. We should be pretty confident by this |
| // point that we've validated the extension ID format, but in case something |
| // slips through, we avoid a class of attack where creative ID manipulation |
| // leads to hash collisions. |
| // 128 bits / 4 = 32 mpdecimal characters |
| return (extension_id.length() == 32); |
| } |
| |
| } // namespace extensions |
