| // Copyright 2013 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/manifest_handlers/csp_info.h" |
| |
| #include <memory> |
| #include <utility> |
| |
| #include "base/feature_list.h" |
| #include "base/no_destructor.h" |
| #include "base/strings/string_piece.h" |
| #include "base/strings/string_util.h" |
| #include "base/strings/utf_string_conversions.h" |
| #include "base/values.h" |
| #include "extensions/common/csp_validator.h" |
| #include "extensions/common/error_utils.h" |
| #include "extensions/common/extension_features.h" |
| #include "extensions/common/install_warning.h" |
| #include "extensions/common/manifest_constants.h" |
| #include "extensions/common/manifest_handlers/sandboxed_page_info.h" |
| |
| namespace extensions { |
| |
| namespace keys = manifest_keys; |
| namespace errors = manifest_errors; |
| |
| using csp_validator::ContentSecurityPolicyIsLegal; |
| using csp_validator::SanitizeContentSecurityPolicy; |
| |
| namespace { |
| |
| const char kDefaultContentSecurityPolicy[] = |
| "script-src 'self' blob: filesystem:; " |
| "object-src 'self' blob: filesystem:;"; |
| |
| const char kDefaultSandboxedPageContentSecurityPolicy[] = |
| "sandbox allow-scripts allow-forms allow-popups allow-modals; " |
| "script-src 'self' 'unsafe-inline' 'unsafe-eval'; child-src 'self';"; |
| |
| #define PLATFORM_APP_LOCAL_CSP_SOURCES "'self' blob: filesystem: data:" |
| |
| // clang-format off |
| const char kDefaultPlatformAppContentSecurityPolicy[] = |
| // Platform apps can only use local resources by default. |
| "default-src 'self' blob: filesystem:;" |
| // For remote resources, they can fetch them via XMLHttpRequest. |
| " connect-src * data: blob: filesystem:;" |
| // And serve them via data: or same-origin (blob:, filesystem:) URLs |
| " style-src " PLATFORM_APP_LOCAL_CSP_SOURCES " 'unsafe-inline';" |
| " img-src " PLATFORM_APP_LOCAL_CSP_SOURCES ";" |
| " frame-src " PLATFORM_APP_LOCAL_CSP_SOURCES ";" |
| " font-src " PLATFORM_APP_LOCAL_CSP_SOURCES ";" |
| // Media can be loaded from remote resources since: |
| // 1. <video> and <audio> have good fallback behavior when offline or under |
| // spotty connectivity. |
| // 2. Fetching via XHR and serving via blob: URLs currently does not allow |
| // streaming or partial buffering. |
| " media-src * data: blob: filesystem:;" |
| // Scripts are allowed to use WebAssembly |
| " script-src 'self' blob: filesystem: 'wasm-eval';"; |
| // clang-format on |
| |
| const char* GetDefaultMV3CSP(absl::optional<bool> allow_wasm = absl::nullopt) { |
| // The default CSP to be used in order to prevent remote scripts. |
| static const char kDefaultMV3CSP[] = "script-src 'self'; object-src 'self';"; |
| |
| // Same as `kDefaultMV3CSP` but allows web assembly usage. |
| static const char kDefaultMV3CSPWithWasmAllowed[] = |
| "script-src 'self' 'wasm-eval'; object-src 'self';"; |
| |
| return allow_wasm.value_or( |
| base::FeatureList::IsEnabled(extensions_features::kAllowWasmInMV3)) |
| ? kDefaultMV3CSPWithWasmAllowed |
| : kDefaultMV3CSP; |
| } |
| |
| int GetValidatorOptions(Extension* extension) { |
| int options = csp_validator::OPTIONS_NONE; |
| |
| // crbug.com/146487 |
| if (extension->GetType() == Manifest::TYPE_EXTENSION || |
| extension->GetType() == Manifest::TYPE_LEGACY_PACKAGED_APP) { |
| options |= csp_validator::OPTIONS_ALLOW_UNSAFE_EVAL; |
| } |
| |
| // Component extensions can specify an insecure object-src directive. This |
| // should be safe because non-NPAPI plugins should load in a sandboxed process |
| // and only allow communication via postMessage. |
| if (extensions::Manifest::IsComponentLocation(extension->location())) |
| options |= csp_validator::OPTIONS_ALLOW_INSECURE_OBJECT_SRC; |
| |
| return options; |
| } |
| |
| std::u16string GetInvalidManifestKeyError(base::StringPiece key) { |
| return ErrorUtils::FormatErrorMessageUTF16(errors::kInvalidManifestKey, key); |
| } |
| |
| // Returns null if the manifest type can't access the path. Else returns the |
| // corresponding Value. |
| const base::Value* GetManifestPath(const Extension* extension, |
| const char* path) { |
| const base::Value* value = nullptr; |
| return extension->manifest()->Get(path, &value) ? value : nullptr; |
| } |
| |
| const char* GetDefaultExtensionPagesCSP(Extension* extension) { |
| if (extension->manifest_version() >= 3) |
| return GetDefaultMV3CSP(); |
| |
| if (extension->GetType() == Manifest::TYPE_PLATFORM_APP) |
| return kDefaultPlatformAppContentSecurityPolicy; |
| |
| return kDefaultContentSecurityPolicy; |
| } |
| |
| } // namespace |
| |
| CSPInfo::CSPInfo(std::string extension_pages_csp) |
| : extension_pages_csp(std::move(extension_pages_csp)) {} |
| |
| CSPInfo::~CSPInfo() { |
| } |
| |
| // static |
| const std::string& CSPInfo::GetExtensionPagesCSP(const Extension* extension) { |
| CSPInfo* csp_info = static_cast<CSPInfo*>( |
| extension->GetManifestData(keys::kContentSecurityPolicy)); |
| return csp_info ? csp_info->extension_pages_csp : base::EmptyString(); |
| } |
| |
| // static |
| const std::string* CSPInfo::GetDefaultCSPToAppend( |
| const Extension& extension, |
| const std::string& relative_path) { |
| if (!extension.is_extension()) |
| return nullptr; |
| |
| // For sandboxed pages and manifest V2 extensions, append the parsed CSP. This |
| // helps ensure that extension's can't get around our parsing rules by CSP |
| // modifications through, say service workers. |
| if (SandboxedPageInfo::IsSandboxedPage(&extension, relative_path)) |
| return &GetSandboxContentSecurityPolicy(&extension); |
| |
| if (extension.manifest_version() <= 2) |
| return &GetExtensionPagesCSP(&extension); |
| |
| // For manifest V3 extensions, append the default secure CSP. This |
| // additionally helps protect against bugs in our CSP parsing code which may |
| // cause the parsed CSP to not be as strong as the default one. For example, |
| // see crbug.com/1042963. |
| static const base::NoDestructor<std::string> default_csp(GetDefaultMV3CSP()); |
| return default_csp.get(); |
| } |
| |
| // static |
| const std::string* CSPInfo::GetIsolatedWorldCSP(const Extension& extension) { |
| if (extension.manifest_version() >= 3) { |
| // The isolated world will use its own CSP which blocks remotely hosted |
| // code. |
| static const base::NoDestructor<std::string> default_isolated_world_csp( |
| GetDefaultMV3CSP(false /* allow_wasm */)); |
| return default_isolated_world_csp.get(); |
| } |
| |
| Manifest::Type type = extension.GetType(); |
| bool bypass_main_world_csp = type == Manifest::TYPE_PLATFORM_APP || |
| type == Manifest::TYPE_EXTENSION || |
| type == Manifest::TYPE_LEGACY_PACKAGED_APP; |
| if (!bypass_main_world_csp) { |
| // The isolated world will use the main world CSP. |
| return nullptr; |
| } |
| |
| // The isolated world will bypass the main world CSP. |
| return &base::EmptyString(); |
| } |
| |
| // static |
| const std::string& CSPInfo::GetSandboxContentSecurityPolicy( |
| const Extension* extension) { |
| CSPInfo* csp_info = static_cast<CSPInfo*>( |
| extension->GetManifestData(keys::kContentSecurityPolicy)); |
| return csp_info ? csp_info->sandbox_csp : base::EmptyString(); |
| } |
| |
| // static |
| const std::string& CSPInfo::GetResourceContentSecurityPolicy( |
| const Extension* extension, |
| const std::string& relative_path) { |
| return SandboxedPageInfo::IsSandboxedPage(extension, relative_path) |
| ? GetSandboxContentSecurityPolicy(extension) |
| : GetExtensionPagesCSP(extension); |
| } |
| |
| CSPHandler::CSPHandler() = default; |
| |
| CSPHandler::~CSPHandler() = default; |
| |
| bool CSPHandler::Parse(Extension* extension, std::u16string* error) { |
| const char* key = extension->GetType() == Manifest::TYPE_PLATFORM_APP |
| ? keys::kPlatformAppContentSecurityPolicy |
| : keys::kContentSecurityPolicy; |
| |
| // The "content_security_policy" manifest key can either be a string or a |
| // dictionary of the format. |
| // "content_security_policy" : { |
| // "extension_pages": "", |
| // "sandbox": "", |
| // } |
| // The dictionary is supported (and mandated) for manifest v3 (and above) |
| // extensions. |
| const base::Value* csp = GetManifestPath(extension, key); |
| bool parse_as_dictionary = extension->manifest_version() >= 3; |
| if (parse_as_dictionary) { |
| if (csp && !csp->is_dict()) { |
| *error = GetInvalidManifestKeyError(key); |
| return false; |
| } |
| return ParseCSPDictionary(extension, error); |
| } |
| |
| if (!ParseExtensionPagesCSP(extension, error, key, csp)) { |
| return false; |
| } |
| |
| if (!ParseSandboxCSP(extension, error, keys::kSandboxedPagesCSP, |
| GetManifestPath(extension, keys::kSandboxedPagesCSP))) { |
| return false; |
| } |
| |
| return true; |
| } |
| |
| bool CSPHandler::ParseCSPDictionary(Extension* extension, |
| std::u16string* error) { |
| // keys::kSandboxedPagesCSP shouldn't be used when using |
| // keys::kContentSecurityPolicy as a dictionary. |
| if (extension->manifest()->HasPath(keys::kSandboxedPagesCSP)) { |
| *error = base::ASCIIToUTF16(errors::kSandboxPagesCSPKeyNotAllowed); |
| return false; |
| } |
| |
| return ParseExtensionPagesCSP( |
| extension, error, keys::kContentSecurityPolicy_ExtensionPagesPath, |
| GetManifestPath( |
| extension, keys::kContentSecurityPolicy_ExtensionPagesPath)) && |
| ParseSandboxCSP( |
| extension, error, keys::kContentSecurityPolicy_SandboxedPagesPath, |
| GetManifestPath(extension, |
| keys::kContentSecurityPolicy_SandboxedPagesPath)); |
| } |
| |
| bool CSPHandler::ParseExtensionPagesCSP( |
| Extension* extension, |
| std::u16string* error, |
| base::StringPiece manifest_key, |
| const base::Value* content_security_policy) { |
| if (!content_security_policy) { |
| return SetExtensionPagesCSP(extension, manifest_key, |
| GetDefaultExtensionPagesCSP(extension)); |
| } |
| |
| if (!content_security_policy->is_string()) { |
| *error = GetInvalidManifestKeyError(manifest_key); |
| return false; |
| } |
| |
| const std::string& content_security_policy_str = |
| content_security_policy->GetString(); |
| if (!ContentSecurityPolicyIsLegal(content_security_policy_str)) { |
| *error = GetInvalidManifestKeyError(manifest_key); |
| return false; |
| } |
| |
| if (extension->manifest_version() >= 3) { |
| if (!csp_validator::DoesCSPDisallowRemoteCode(content_security_policy_str, |
| manifest_key, error)) { |
| return false; |
| } |
| SetExtensionPagesCSP(extension, manifest_key, content_security_policy_str); |
| return true; |
| } |
| |
| std::vector<InstallWarning> warnings; |
| std::string sanitized_content_security_policy = SanitizeContentSecurityPolicy( |
| content_security_policy_str, std::string(manifest_key), |
| GetValidatorOptions(extension), &warnings); |
| extension->AddInstallWarnings(std::move(warnings)); |
| |
| SetExtensionPagesCSP(extension, manifest_key, |
| std::move(sanitized_content_security_policy)); |
| return true; |
| } |
| |
| bool CSPHandler::ParseSandboxCSP(Extension* extension, |
| std::u16string* error, |
| base::StringPiece manifest_key, |
| const base::Value* sandbox_csp) { |
| if (!sandbox_csp) { |
| SetSandboxCSP(extension, kDefaultSandboxedPageContentSecurityPolicy); |
| return true; |
| } |
| |
| if (!sandbox_csp->is_string()) { |
| *error = GetInvalidManifestKeyError(manifest_key); |
| return false; |
| } |
| |
| const std::string& sandbox_csp_str = sandbox_csp->GetString(); |
| if (!ContentSecurityPolicyIsLegal(sandbox_csp_str) || |
| !csp_validator::ContentSecurityPolicyIsSandboxed(sandbox_csp_str, |
| extension->GetType())) { |
| *error = GetInvalidManifestKeyError(manifest_key); |
| return false; |
| } |
| |
| std::vector<InstallWarning> warnings; |
| std::string effective_sandbox_csp = |
| csp_validator::GetEffectiveSandoxedPageCSP( |
| sandbox_csp_str, std::string(manifest_key), &warnings); |
| SetSandboxCSP(extension, std::move(effective_sandbox_csp)); |
| extension->AddInstallWarnings(std::move(warnings)); |
| return true; |
| } |
| |
| bool CSPHandler::SetExtensionPagesCSP(Extension* extension, |
| base::StringPiece manifest_key, |
| std::string content_security_policy) { |
| if (extension->manifest_version() >= 3) { |
| std::u16string error; |
| DCHECK(csp_validator::DoesCSPDisallowRemoteCode(content_security_policy, |
| manifest_key, &error)); |
| } else { |
| DCHECK_EQ(content_security_policy, |
| SanitizeContentSecurityPolicy( |
| content_security_policy, std::string(manifest_key), |
| GetValidatorOptions(extension), nullptr)); |
| } |
| |
| extension->SetManifestData( |
| keys::kContentSecurityPolicy, |
| std::make_unique<CSPInfo>(std::move(content_security_policy))); |
| return true; |
| } |
| |
| void CSPHandler::SetSandboxCSP(Extension* extension, std::string sandbox_csp) { |
| CHECK(csp_validator::ContentSecurityPolicyIsSandboxed(sandbox_csp, |
| extension->GetType())); |
| |
| // By now we must have parsed the extension page CSP. |
| CSPInfo* csp_info = static_cast<CSPInfo*>( |
| extension->GetManifestData(keys::kContentSecurityPolicy)); |
| DCHECK(csp_info); |
| csp_info->sandbox_csp = std::move(sandbox_csp); |
| } |
| |
| bool CSPHandler::AlwaysParseForType(Manifest::Type type) const { |
| // TODO(crbug.com/1005978): Check if TYPE_USER_SCRIPT needs to be included |
| // here. |
| return type == Manifest::TYPE_PLATFORM_APP || |
| type == Manifest::TYPE_EXTENSION || |
| type == Manifest::TYPE_LEGACY_PACKAGED_APP; |
| } |
| |
| base::span<const char* const> CSPHandler::Keys() const { |
| static constexpr const char* kKeys[] = { |
| keys::kContentSecurityPolicy, keys::kPlatformAppContentSecurityPolicy, |
| keys::kSandboxedPagesCSP}; |
| return kKeys; |
| } |
| |
| } // namespace extensions |