chrome/updater/tag.h - chromium/src - Git at Google

 // Copyright 2020 The Chromium Authors
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.

 #ifndef CHROME_UPDATER_TAG_H_
 #define CHROME_UPDATER_TAG_H_

 #include <cstdint>
 #include <optional>
 #include <ostream>
 #include <string>
 #include <string_view>
 #include <utility>
 #include <vector>

 #include "base/files/file_path.h"
 #include "base/types/expected.h"
 #include "build/build_config.h"

 namespace updater::tagging {
 namespace internal {

 // Advances the iterator by |distance| and makes sure that it remains valid,
 // else returns |end|.
 std::vector<uint8_t>::const_iterator AdvanceIt(
     std::vector<uint8_t>::const_iterator it,
     size_t distance,
     std::vector<uint8_t>::const_iterator end);

 // Checks that the range [it, it + size) is found within the binary. |size| must
 // be > 0.
 bool CheckRange(std::vector<uint8_t>::const_iterator it,
                 size_t size,
                 std::vector<uint8_t>::const_iterator end);

 }  // namespace internal

 // Represents application requirements for admin.
 enum class NeedsAdmin {
   // The application will install per user.
   kNo = 0,
   // The application will install machine-wide.
   kYes,
   // The application will install machine-wide if permissions allow, else will
   // install per-user.
   kPrefers,
 };

 // This struct contains the attributes for a given app parsed from a part of the
 // metainstaller tag. It contains minimal policy and is intended to be a
 // near-direct mapping from tag to memory. See TagArgs, which stores a list of
 // these.
 //
 // An empty string in std::string members indicates that the given attribute did
 // not appear in the tag for this app.
 struct AppArgs {
   // |app_id| must not be empty and will be made lowercase.
   explicit AppArgs(std::string_view app_id);

   ~AppArgs();
   AppArgs(const AppArgs&);
   AppArgs& operator=(const AppArgs&);
   AppArgs(AppArgs&&);
   AppArgs& operator=(AppArgs&&);

   // An ASCII-encoded lowercase string. Must not be empty.
   std::string app_id;
   std::string app_name;
   std::string ap;
   std::string encoded_installer_data;
   std::string install_data_index;
   std::string experiment_labels;
   std::string untrusted_data;
   std::optional<NeedsAdmin> needs_admin;
 };

 std::ostream& operator<<(std::ostream&, const NeedsAdmin&);

 // This struct contains the "runtime mode" parsed from the metainstaller tag.
 struct RuntimeModeArgs {
   auto operator<=>(const RuntimeModeArgs&) const = default;
   std::optional<NeedsAdmin> needs_admin;
 };

 // This struct contains the attributes parsed from a metainstaller tag. An empty
 // string in std::string members indicates that the given attribute did not
 // appear in the tag.
 struct TagArgs {
   // Must be kept in sync with the enum in
   // `google_update\google_update_idl.idl`. Do not include `BrowserType::kMax`
   // in the IDL file. Do not move or remove existing elements.
   enum class BrowserType {
     kUnknown = 0,
     kDefault = 1,
     kInternetExplorer = 2,
     kFirefox = 3,
     kChrome = 4,
     // Add new browsers above this.
     kMax
   };

   TagArgs();
   ~TagArgs();
   TagArgs(const TagArgs&);
   TagArgs& operator=(const TagArgs&);
   TagArgs(TagArgs&&);
   TagArgs& operator=(TagArgs&&);

   std::string bundle_name;
   std::string installation_id;
   std::string brand_code;
   std::string client_id;
   std::string experiment_labels;
   std::string referral_id;
   std::string language;
   std::optional<BrowserType> browser_type;
   std::optional<bool> flighting = false;
   std::optional<bool> usage_stats_enable;
   std::string enrollment_token;

   // List of apps to install.
   std::vector<AppArgs> apps;

   // This member is present if the "runtime mode" was provided on the command
   // line.
   std::optional<RuntimeModeArgs> runtime_mode;

   // The original tag string.
   std::string tag_string;

   // Vector of name/value attributes from the tag.
   std::vector<std::pair<std::string, std::string>> attributes;
 };

 std::ostream& operator<<(std::ostream&, const TagArgs::BrowserType&);

 // List of possible error states that the parser can encounter.
 enum class ErrorCode {
   // Parsing succeeded.
   kSuccess,

   // The attribute's name is unrecognized as an arg parameter.
   kUnrecognizedName,

   // The tag contains disallowed characters.
   // See |kDisallowedCharsInExtraArgs|.
   kTagIsInvalid,

   // All attributes require a value.
   kAttributeMustHaveValue,

   // An app attribute was specified before an app id was specified.
   kApp_AppIdNotSpecified,

   // The app's experiment label cannot be whitespace.
   kApp_ExperimentLabelsCannotBeWhitespace,

   // The specified app id is not a valid.
   // It must be ASCII-encoded and 512 bytes or less.
   kApp_AppIdIsNotValid,

   // The app name cannot be whitespace.
   kApp_AppNameCannotBeWhitespace,

   // The needsadmin value must be "yes", "no", or "prefers".
   kApp_NeedsAdminValueIsInvalid,

   // No app matches provided app id. Installer data can only be added to an app
   // that has been previously specified in the TagArgs.
   kAppInstallerData_AppIdNotFound,

   // Cannot specify installer data before specifying at least one app id.
   kAppInstallerData_InstallerDataCannotBeSpecifiedBeforeAppId,

   // The bundle name cannot be whitespace.
   kGlobal_BundleNameCannotBeWhitespace,

   // The updater experiment label cannot be whitespace.
   kGlobal_ExperimentLabelsCannotBeWhitespace,

   // The browser type specified is invalid. It must be an integer matching the
   // TagArgs::BrowserType enum.
   kGlobal_BrowserTypeIsInvalid,

   // The flighting value could not be parsed as a boolean.
   kGlobal_FlightingValueIsNotABoolean,

   // The usage stats value must be 0 or 1.
   // Note: A value of 2 is considered the same as not specifying the usage
   // stats.
   kGlobal_UsageStatsValueIsInvalid,

   // The runtime value must be "true", "persist", or "false". The values
   // "persist" and "false" are only for backward compatibility in case someone
   // uses it as an oversight, and are treated the same as "true".
   kGlobal_RuntimeModeValueIsInvalid,

   // The needsadmin value must be "yes", "no", or "prefers".
   kRuntimeMode_NeedsAdminValueIsInvalid,

   // The enrollment token must be a GUID.
   kGlobal_EnrollmentTokenValueIsInvalid,

   // No tag was found when attempting to extract one from a binary or other
   // potentially-tagged content.
   kTagNotFound,
 };

 std::ostream& operator<<(std::ostream&, const ErrorCode&);

 // The metainstaller tag contains the metadata used to configure the updater as
 // a metainstaller. This usually comes from a 3rd party source, either as
 // command-line arguments or embedded in the metainstaller image after it is
 // signed.
 //
 // The metainstaller is generic. It gets bound to a specific application by
 // using this configuration.
 //
 // This function parses |tag| and |app_installer_data_args| into |args|.
 //
 // |tag| is a querystring-encoded ordered list of key-value pairs. All values
 // are unescaped from url-encoding. The following keys are valid and affect the
 // global parameters and have the following constraints on the value:
 // - bundlename        Must not contain only whitespace.
 // - iid               Can be any string.
 // - brand             Can be any string; usually 4 uppercase alphabetic chars.
 // - client            Can be any string.
 // - omahaexperiments  Must not contain only whitespace.
 // - referral          Can be any string.
 // - browser           Must be a positive integer greater than 0 and less than
 //                     TagArgs::BrowserType::kMax.
 // - lang              Can be any string.
 // - flighting         Must be "true" or "false".
 // - usagestats        Must be "0", "1", or "2".
 // - runtime           Must be "true", "false".
 // - etoken            Must be a GUID.
 //
 // The following keys specify app-specific attributes. "appid" must be specified
 // before any other app attribute to specify the "current" app. Other app
 // attributes will then affect the parameters of the most recently specified app
 // ID. For example, if the tag is
 // "appid=App1&ap=ApApp1&brand=GBRN&appid=App2&ap=ApApp2&iid=GlobalInstallId",
 // the resulting tag will look like:
 //   TagArgs {
 //     iid = GlobalInstallId
 //     brand = GBRN
 //     apps = [
 //       AppArgs {
 //         appid = App1
 //         ap = ApApp1
 //       }
 //       AppArgs {
 //         appid = App2
 //         ap = ApApp2
 //       }
 //     ]
 //   }
 // These attributes have the following constraints on the value:
 // - appid             Can be any ASCII string. Case-insensitive.
 // - ap                Can be any string.
 // - experiments       Must not contain only whitespace.
 // - appname           Must not contain only whitespace.
 // - needsadmin        Must be "yes", "no", or "prefers".
 // - installdataindex  Can by any string.
 // - untrusteddata     Can be any string.
 //
 // |app_installer_data_args| is also a querystring-encoded ordered list of
 // key-value pairs. Unlike in the |tag|, the values are escaped. The following
 // keys are valid and affect the app installer data parameters and have the
 // following constraints on the value:
 // - appid        Must be a valid app id specified in |tag|.
 // - installerdata  Can be any string. Must be specified after appid.
 //
 // Note: This method assumes all attribute names are ASCII.
 ErrorCode Parse(std::string_view tag,
                 std::optional<std::string_view> app_installer_data_args,
                 TagArgs& args);

 // Utilities for reading and writing tags to Windows PE and MSI files.
 //
 //
 // The tag specification is as follows:
 //   - The tag area begins with a magic signature 'Gact2.0Omaha'.
 //   - The next 2 bytes are the tag string length in big endian.
 //   - Then comes the tag string in the format "key1=value1&key2=value2".
 //   - The key is alphanumeric, the value allows special characters such as '*'.
 //
 // A sample layout:
 // +-------------------------------------+
 // ~    ..............................   ~
 // |    ..............................   |
 // |    Other parts of the file          |
 // +-------------------------------------+
 // | Start of the certificate            |
 // ~    ..............................   ~
 // ~    ..............................   ~
 // | Magic signature 'Gact2.0Omaha'      | Tag starts
 // | Tag length (2 bytes in big-endian)) |
 // | tag string                          |
 // +-------------------------------------+
 //
 // A real example (an MSI file tagged with 'brand=CDCD&key2=Test'):
 // +-----------------------------------------------------------------+
 // |  G   a   c   t   2   .   0   O   m   a   h   a  0x0 0x14 b   r  |
 // |  a   n   d   =   C   D   C   D   &   k   e   y   2   =   T   e  |
 // |  s   t                                                          |
 // +-----------------------------------------------------------------+
 // Extracts a tag from `filename`.
 std::string BinaryReadTagString(const base::FilePath& file);
 std::optional<tagging::TagArgs> BinaryReadTag(const base::FilePath& file);

 // ReadTag extracts the tag string from a region of binary data. This string
 // does not include the magic signature or tag length itself. If no tag can
 // be found, this returns the empty string.
 std::string ReadTag(std::vector<uint8_t>::const_iterator begin,
                     std::vector<uint8_t>::const_iterator end);

 // GetTagFromTagString creates binary tag data from a specified tag string by
 // prefixing it with the signature and length.
 std::vector<uint8_t> GetTagFromTagString(const std::string& tag_string);

 // Tags `file` with `tag_string` and writes the result to `file` by default, or
 // to `out_file` if `out_file` is provided.
 bool BinaryWriteTag(const base::FilePath& in_file,
                     const std::string& tag_string,
                     int padded_length,
                     base::FilePath out_file);

 #if BUILDFLAG(IS_MAC)

 // Reads the `com.apple.application-instance` extended attribute from the item
 // at `path`, parsing it as a complete metainstaller tag, including the
 // "Gact2.0Omaha" magic number prefix.
 //
 // If the file exists, has this specific extended attribute, this process can
 // read that attribute, and this process can parse a complete metainstaller
 // tag out of it, this returns the parsed `tagging::TagArgs`. If any of the
 // prerequisites before tag content parsing fail, this returns the "no tag"
 // error code. If tag parsing fails, this returns the error code from tag
 // parsing.
 base::expected<TagArgs, ErrorCode> ReadTagFromApplicationInstanceXattr(
     const base::FilePath& path);

 // Overwrites the `com.apple.application-instance` extended attribute on the
 // item at `path` with a formatted binary tag containing the provided string,
 // prefixed with the "Gact2.0Omaha" signature and size, as described above.
 // It does not check the validity of the string as a tag. Returns `true` on
 // success, `false` on failure.
 bool WriteTagStringToApplicationInstanceXattr(const base::FilePath& path,
                                               const std::string& tag_string);

 #endif  // BUILDFLAG(IS_MAC)

 }  // namespace updater::tagging

 #endif  // CHROME_UPDATER_TAG_H_
	// Copyright 2020 The Chromium Authors
	// Use of this source code is governed by a BSD-style license that can be
	// found in the LICENSE file.

	#ifndef CHROME_UPDATER_TAG_H_
	#define CHROME_UPDATER_TAG_H_

	#include <cstdint>
	#include <optional>
	#include <ostream>
	#include <string>
	#include <string_view>
	#include <utility>
	#include <vector>

	#include "base/files/file_path.h"
	#include "base/types/expected.h"
	#include "build/build_config.h"

	namespace updater::tagging {
	namespace internal {

	// Advances the iterator by \|distance\| and makes sure that it remains valid,
	// else returns \|end\|.
	std::vector<uint8_t>::const_iterator AdvanceIt(
	std::vector<uint8_t>::const_iterator it,
	size_t distance,
	std::vector<uint8_t>::const_iterator end);

	// Checks that the range [it, it + size) is found within the binary. \|size\| must
	// be > 0.
	bool CheckRange(std::vector<uint8_t>::const_iterator it,
	size_t size,
	std::vector<uint8_t>::const_iterator end);

	} // namespace internal

	// Represents application requirements for admin.
	enum class NeedsAdmin {
	// The application will install per user.
	kNo = 0,
	// The application will install machine-wide.
	kYes,
	// The application will install machine-wide if permissions allow, else will
	// install per-user.
	kPrefers,
	};

	// This struct contains the attributes for a given app parsed from a part of the
	// metainstaller tag. It contains minimal policy and is intended to be a
	// near-direct mapping from tag to memory. See TagArgs, which stores a list of
	// these.
	//
	// An empty string in std::string members indicates that the given attribute did
	// not appear in the tag for this app.
	struct AppArgs {
	// \|app_id\| must not be empty and will be made lowercase.
	explicit AppArgs(std::string_view app_id);

	~AppArgs();
	AppArgs(const AppArgs&);
	AppArgs& operator=(const AppArgs&);
	AppArgs(AppArgs&&);
	AppArgs& operator=(AppArgs&&);

	// An ASCII-encoded lowercase string. Must not be empty.
	std::string app_id;
	std::string app_name;
	std::string ap;
	std::string encoded_installer_data;
	std::string install_data_index;
	std::string experiment_labels;
	std::string untrusted_data;
	std::optional<NeedsAdmin> needs_admin;
	};

	std::ostream& operator<<(std::ostream&, const NeedsAdmin&);

	// This struct contains the "runtime mode" parsed from the metainstaller tag.
	struct RuntimeModeArgs {
	auto operator<=>(const RuntimeModeArgs&) const = default;
	std::optional<NeedsAdmin> needs_admin;
	};

	// This struct contains the attributes parsed from a metainstaller tag. An empty
	// string in std::string members indicates that the given attribute did not
	// appear in the tag.
	struct TagArgs {
	// Must be kept in sync with the enum in
	// `google_update\google_update_idl.idl`. Do not include `BrowserType::kMax`
	// in the IDL file. Do not move or remove existing elements.
	enum class BrowserType {
	kUnknown = 0,
	kDefault = 1,
	kInternetExplorer = 2,
	kFirefox = 3,
	kChrome = 4,
	// Add new browsers above this.
	kMax
	};

	TagArgs();
	~TagArgs();
	TagArgs(const TagArgs&);
	TagArgs& operator=(const TagArgs&);
	TagArgs(TagArgs&&);
	TagArgs& operator=(TagArgs&&);

	std::string bundle_name;
	std::string installation_id;
	std::string brand_code;
	std::string client_id;
	std::string experiment_labels;
	std::string referral_id;
	std::string language;
	std::optional<BrowserType> browser_type;
	std::optional<bool> flighting = false;
	std::optional<bool> usage_stats_enable;
	std::string enrollment_token;

	// List of apps to install.
	std::vector<AppArgs> apps;

	// This member is present if the "runtime mode" was provided on the command
	// line.
	std::optional<RuntimeModeArgs> runtime_mode;

	// The original tag string.
	std::string tag_string;

	// Vector of name/value attributes from the tag.
	std::vector<std::pair<std::string, std::string>> attributes;
	};

	std::ostream& operator<<(std::ostream&, const TagArgs::BrowserType&);

	// List of possible error states that the parser can encounter.
	enum class ErrorCode {
	// Parsing succeeded.
	kSuccess,

	// The attribute's name is unrecognized as an arg parameter.
	kUnrecognizedName,

	// The tag contains disallowed characters.
	// See \|kDisallowedCharsInExtraArgs\|.
	kTagIsInvalid,

	// All attributes require a value.
	kAttributeMustHaveValue,

	// An app attribute was specified before an app id was specified.
	kApp_AppIdNotSpecified,

	// The app's experiment label cannot be whitespace.
	kApp_ExperimentLabelsCannotBeWhitespace,

	// The specified app id is not a valid.
	// It must be ASCII-encoded and 512 bytes or less.
	kApp_AppIdIsNotValid,

	// The app name cannot be whitespace.
	kApp_AppNameCannotBeWhitespace,

	// The needsadmin value must be "yes", "no", or "prefers".
	kApp_NeedsAdminValueIsInvalid,

	// No app matches provided app id. Installer data can only be added to an app
	// that has been previously specified in the TagArgs.
	kAppInstallerData_AppIdNotFound,

	// Cannot specify installer data before specifying at least one app id.
	kAppInstallerData_InstallerDataCannotBeSpecifiedBeforeAppId,

	// The bundle name cannot be whitespace.
	kGlobal_BundleNameCannotBeWhitespace,

	// The updater experiment label cannot be whitespace.
	kGlobal_ExperimentLabelsCannotBeWhitespace,

	// The browser type specified is invalid. It must be an integer matching the
	// TagArgs::BrowserType enum.
	kGlobal_BrowserTypeIsInvalid,

	// The flighting value could not be parsed as a boolean.
	kGlobal_FlightingValueIsNotABoolean,

	// The usage stats value must be 0 or 1.
	// Note: A value of 2 is considered the same as not specifying the usage
	// stats.
	kGlobal_UsageStatsValueIsInvalid,

	// The runtime value must be "true", "persist", or "false". The values
	// "persist" and "false" are only for backward compatibility in case someone
	// uses it as an oversight, and are treated the same as "true".
	kGlobal_RuntimeModeValueIsInvalid,

	// The needsadmin value must be "yes", "no", or "prefers".
	kRuntimeMode_NeedsAdminValueIsInvalid,

	// The enrollment token must be a GUID.
	kGlobal_EnrollmentTokenValueIsInvalid,

	// No tag was found when attempting to extract one from a binary or other
	// potentially-tagged content.
	kTagNotFound,
	};

	std::ostream& operator<<(std::ostream&, const ErrorCode&);

	// The metainstaller tag contains the metadata used to configure the updater as
	// a metainstaller. This usually comes from a 3rd party source, either as
	// command-line arguments or embedded in the metainstaller image after it is
	// signed.
	//
	// The metainstaller is generic. It gets bound to a specific application by
	// using this configuration.
	//
	// This function parses \|tag\| and \|app_installer_data_args\| into \|args\|.
	//
	// \|tag\| is a querystring-encoded ordered list of key-value pairs. All values
	// are unescaped from url-encoding. The following keys are valid and affect the
	// global parameters and have the following constraints on the value:
	// - bundlename Must not contain only whitespace.
	// - iid Can be any string.
	// - brand Can be any string; usually 4 uppercase alphabetic chars.
	// - client Can be any string.
	// - omahaexperiments Must not contain only whitespace.
	// - referral Can be any string.
	// - browser Must be a positive integer greater than 0 and less than
	// TagArgs::BrowserType::kMax.
	// - lang Can be any string.
	// - flighting Must be "true" or "false".
	// - usagestats Must be "0", "1", or "2".
	// - runtime Must be "true", "false".
	// - etoken Must be a GUID.
	//
	// The following keys specify app-specific attributes. "appid" must be specified
	// before any other app attribute to specify the "current" app. Other app
	// attributes will then affect the parameters of the most recently specified app
	// ID. For example, if the tag is
	// "appid=App1&ap=ApApp1&brand=GBRN&appid=App2&ap=ApApp2&iid=GlobalInstallId",
	// the resulting tag will look like:
	// TagArgs {
	// iid = GlobalInstallId
	// brand = GBRN
	// apps = [
	// AppArgs {
	// appid = App1
	// ap = ApApp1
	// }
	// AppArgs {
	// appid = App2
	// ap = ApApp2
	// }
	// ]
	// }
	// These attributes have the following constraints on the value:
	// - appid Can be any ASCII string. Case-insensitive.
	// - ap Can be any string.
	// - experiments Must not contain only whitespace.
	// - appname Must not contain only whitespace.
	// - needsadmin Must be "yes", "no", or "prefers".
	// - installdataindex Can by any string.
	// - untrusteddata Can be any string.
	//
	// \|app_installer_data_args\| is also a querystring-encoded ordered list of
	// key-value pairs. Unlike in the \|tag\|, the values are escaped. The following
	// keys are valid and affect the app installer data parameters and have the
	// following constraints on the value:
	// - appid Must be a valid app id specified in \|tag\|.
	// - installerdata Can be any string. Must be specified after appid.
	//
	// Note: This method assumes all attribute names are ASCII.
	ErrorCode Parse(std::string_view tag,
	std::optional<std::string_view> app_installer_data_args,
	TagArgs& args);

	// Utilities for reading and writing tags to Windows PE and MSI files.
	//
	//
	// The tag specification is as follows:
	// - The tag area begins with a magic signature 'Gact2.0Omaha'.
	// - The next 2 bytes are the tag string length in big endian.
	// - Then comes the tag string in the format "key1=value1&key2=value2".
	// - The key is alphanumeric, the value allows special characters such as '*'.
	//
	// A sample layout:
	// +-------------------------------------+
	// ~ .............................. ~
	// \| .............................. \|
	// \| Other parts of the file \|
	// +-------------------------------------+
	// \| Start of the certificate \|
	// ~ .............................. ~
	// ~ .............................. ~
	// \| Magic signature 'Gact2.0Omaha' \| Tag starts
	// \| Tag length (2 bytes in big-endian)) \|
	// \| tag string \|
	// +-------------------------------------+
	//
	// A real example (an MSI file tagged with 'brand=CDCD&key2=Test'):
	// +-----------------------------------------------------------------+
	// \| G a c t 2 . 0 O m a h a 0x0 0x14 b r \|
	// \| a n d = C D C D & k e y 2 = T e \|
	// \| s t \|
	// +-----------------------------------------------------------------+
	// Extracts a tag from `filename`.
	std::string BinaryReadTagString(const base::FilePath& file);
	std::optional<tagging::TagArgs> BinaryReadTag(const base::FilePath& file);

	// ReadTag extracts the tag string from a region of binary data. This string
	// does not include the magic signature or tag length itself. If no tag can
	// be found, this returns the empty string.
	std::string ReadTag(std::vector<uint8_t>::const_iterator begin,
	std::vector<uint8_t>::const_iterator end);

	// GetTagFromTagString creates binary tag data from a specified tag string by
	// prefixing it with the signature and length.
	std::vector<uint8_t> GetTagFromTagString(const std::string& tag_string);

	// Tags `file` with `tag_string` and writes the result to `file` by default, or
	// to `out_file` if `out_file` is provided.
	bool BinaryWriteTag(const base::FilePath& in_file,
	const std::string& tag_string,
	int padded_length,
	base::FilePath out_file);

	#if BUILDFLAG(IS_MAC)

	// Reads the `com.apple.application-instance` extended attribute from the item
	// at `path`, parsing it as a complete metainstaller tag, including the
	// "Gact2.0Omaha" magic number prefix.
	//
	// If the file exists, has this specific extended attribute, this process can
	// read that attribute, and this process can parse a complete metainstaller
	// tag out of it, this returns the parsed `tagging::TagArgs`. If any of the
	// prerequisites before tag content parsing fail, this returns the "no tag"
	// error code. If tag parsing fails, this returns the error code from tag
	// parsing.
	base::expected<TagArgs, ErrorCode> ReadTagFromApplicationInstanceXattr(
	const base::FilePath& path);

	// Overwrites the `com.apple.application-instance` extended attribute on the
	// item at `path` with a formatted binary tag containing the provided string,
	// prefixed with the "Gact2.0Omaha" signature and size, as described above.
	// It does not check the validity of the string as a tag. Returns `true` on
	// success, `false` on failure.
	bool WriteTagStringToApplicationInstanceXattr(const base::FilePath& path,
	const std::string& tag_string);

	#endif // BUILDFLAG(IS_MAC)

	} // namespace updater::tagging

	#endif // CHROME_UPDATER_TAG_H_