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// This file declares methods that are useful for integrating Chrome in
6// Windows shell. These methods are all static and currently part of
7// ShellUtil class.
8
9#ifndef CHROME_INSTALLER_UTIL_SHELL_UTIL_H_
10#define CHROME_INSTALLER_UTIL_SHELL_UTIL_H_
11
12#include <windows.h>
13
14#include <map>
15#include <utility>
16#include <vector>
17
18#include "base/basictypes.h"
19#include "base/files/file_path.h"
20#include "base/logging.h"
21#include "base/memory/ref_counted.h"
22#include "base/strings/string16.h"
23#include "chrome/installer/util/work_item_list.h"
24
25class BrowserDistribution;
26
27namespace base {
28class CancellationFlag;
29}
30
31// This is a utility class that provides common shell integration methods
32// that can be used by installer as well as Chrome.
33class ShellUtil {
34 public:
35  // Input to any methods that make changes to OS shell.
36  enum ShellChange {
37    CURRENT_USER = 0x1,  // Make any shell changes only at the user level
38    SYSTEM_LEVEL = 0x2   // Make any shell changes only at the system level
39  };
40
41  // Chrome's default handler state for a given protocol.
42  enum DefaultState {
43    UNKNOWN_DEFAULT,
44    NOT_DEFAULT,
45    IS_DEFAULT,
46  };
47
48  // Typical shortcut directories. Resolved in GetShortcutPath().
49  // Also used in ShortcutLocationIsSupported().
50  enum ShortcutLocation {
51    SHORTCUT_LOCATION_FIRST = 0,
52    SHORTCUT_LOCATION_DESKTOP = SHORTCUT_LOCATION_FIRST,
53    SHORTCUT_LOCATION_QUICK_LAUNCH,
54    SHORTCUT_LOCATION_START_MENU_ROOT,
55    SHORTCUT_LOCATION_START_MENU_CHROME_DIR,
56    SHORTCUT_LOCATION_START_MENU_CHROME_APPS_DIR,
57    SHORTCUT_LOCATION_TASKBAR_PINS,  // base::win::VERSION_WIN7 +
58    SHORTCUT_LOCATION_APP_SHORTCUTS,  // base::win::VERSION_WIN8 +
59    NUM_SHORTCUT_LOCATIONS
60  };
61
62  enum ShortcutOperation {
63    // Create a new shortcut (overwriting if necessary).
64    SHELL_SHORTCUT_CREATE_ALWAYS,
65    // Create the per-user shortcut only if its system-level equivalent (with
66    // the same name) is not present.
67    SHELL_SHORTCUT_CREATE_IF_NO_SYSTEM_LEVEL,
68    // Overwrite an existing shortcut (fail if the shortcut doesn't exist).
69    // If the arguments are not specified on the new shortcut, keep the old
70    // shortcut's arguments.
71    SHELL_SHORTCUT_REPLACE_EXISTING,
72    // Update specified properties only on an existing shortcut.
73    SHELL_SHORTCUT_UPDATE_EXISTING,
74  };
75
76  // Properties for shortcuts. Properties set will be applied to
77  // the shortcut on creation/update. On update, unset properties are ignored;
78  // on create (and replaced) unset properties might have a default value (see
79  // individual property setters below for details).
80  // Callers are encouraged to use the setters provided which take care of
81  // setting |options| as desired.
82  struct ShortcutProperties {
83    enum IndividualProperties {
84      PROPERTIES_TARGET = 1 << 0,
85      PROPERTIES_ARGUMENTS = 1 << 1,
86      PROPERTIES_DESCRIPTION = 1 << 2,
87      PROPERTIES_ICON = 1 << 3,
88      PROPERTIES_APP_ID = 1 << 4,
89      PROPERTIES_SHORTCUT_NAME = 1 << 5,
90      PROPERTIES_DUAL_MODE = 1 << 6,
91    };
92
93    explicit ShortcutProperties(ShellChange level_in)
94        : level(level_in), icon_index(0), dual_mode(false),
95          pin_to_taskbar(false), options(0U) {}
96
97    // Sets the target executable to launch from this shortcut.
98    // This is mandatory when creating a shortcut.
99    void set_target(const base::FilePath& target_in) {
100      target = target_in;
101      options |= PROPERTIES_TARGET;
102    }
103
104    // Sets the arguments to be passed to |target| when launching from this
105    // shortcut.
106    // The length of this string must be less than MAX_PATH.
107    void set_arguments(const base::string16& arguments_in) {
108      // Size restriction as per MSDN at
109      // http://msdn.microsoft.com/library/windows/desktop/bb774954.aspx.
110      DCHECK(arguments_in.length() < MAX_PATH);
111      arguments = arguments_in;
112      options |= PROPERTIES_ARGUMENTS;
113    }
114
115    // Sets the localized description of the shortcut.
116    // The length of this string must be less than MAX_PATH.
117    void set_description(const base::string16& description_in) {
118      // Size restriction as per MSDN at
119      // http://msdn.microsoft.com/library/windows/desktop/bb774955.aspx.
120      DCHECK(description_in.length() < MAX_PATH);
121      description = description_in;
122      options |= PROPERTIES_DESCRIPTION;
123    }
124
125    // Sets the path to the icon (icon_index set to 0).
126    // icon index unless otherwise specified in master_preferences).
127    void set_icon(const base::FilePath& icon_in, int icon_index_in) {
128      icon = icon_in;
129      icon_index = icon_index_in;
130      options |= PROPERTIES_ICON;
131    }
132
133    // Sets the app model id for the shortcut (Win7+).
134    void set_app_id(const base::string16& app_id_in) {
135      app_id = app_id_in;
136      options |= PROPERTIES_APP_ID;
137    }
138
139    // Forces the shortcut's name to |shortcut_name_in|.
140    // Default: the current distribution's GetShortcutName(SHORTCUT_CHROME).
141    // The ".lnk" extension will automatically be added to this name.
142    void set_shortcut_name(const base::string16& shortcut_name_in) {
143      shortcut_name = shortcut_name_in;
144      options |= PROPERTIES_SHORTCUT_NAME;
145    }
146
147    // Sets whether this is a dual mode shortcut (Win8+).
148    // NOTE: Only the default (no arguments and default browser appid) browser
149    // shortcut in the Start menu (Start screen on Win8+) should be made dual
150    // mode.
151    void set_dual_mode(bool dual_mode_in) {
152      dual_mode = dual_mode_in;
153      options |= PROPERTIES_DUAL_MODE;
154    }
155
156    // Sets whether to pin this shortcut to the taskbar after creating it
157    // (ignored if the shortcut is only being updated).
158    // Note: This property doesn't have a mask in |options|.
159    void set_pin_to_taskbar(bool pin_to_taskbar_in) {
160      pin_to_taskbar = pin_to_taskbar_in;
161    }
162
163    bool has_target() const {
164      return (options & PROPERTIES_TARGET) != 0;
165    }
166
167    bool has_arguments() const {
168      return (options & PROPERTIES_ARGUMENTS) != 0;
169    }
170
171    bool has_description() const {
172      return (options & PROPERTIES_DESCRIPTION) != 0;
173    }
174
175    bool has_icon() const {
176      return (options & PROPERTIES_ICON) != 0;
177    }
178
179    bool has_app_id() const {
180      return (options & PROPERTIES_APP_ID) != 0;
181    }
182
183    bool has_shortcut_name() const {
184      return (options & PROPERTIES_SHORTCUT_NAME) != 0;
185    }
186
187    bool has_dual_mode() const {
188      return (options & PROPERTIES_DUAL_MODE) != 0;
189    }
190
191    // The level to install this shortcut at (CURRENT_USER for a per-user
192    // shortcut and SYSTEM_LEVEL for an all-users shortcut).
193    ShellChange level;
194
195    base::FilePath target;
196    base::string16 arguments;
197    base::string16 description;
198    base::FilePath icon;
199    int icon_index;
200    base::string16 app_id;
201    base::string16 shortcut_name;
202    bool dual_mode;
203    bool pin_to_taskbar;
204    // Bitfield made of IndividualProperties. Properties set in |options| will
205    // be used to create/update the shortcut, others will be ignored on update
206    // and possibly replaced by default values on create (see individual
207    // property setters above for details on default values).
208    uint32 options;
209  };
210
211  // Relative path of the URL Protocol registry entry (prefixed with '\').
212  static const wchar_t* kRegURLProtocol;
213
214  // Relative path of DefaultIcon registry entry (prefixed with '\').
215  static const wchar_t* kRegDefaultIcon;
216
217  // Relative path of "shell" registry key.
218  static const wchar_t* kRegShellPath;
219
220  // Relative path of shell open command in Windows registry
221  // (i.e. \\shell\\open\\command).
222  static const wchar_t* kRegShellOpen;
223
224  // Relative path of registry key under which applications need to register
225  // to control Windows Start menu links.
226  static const wchar_t* kRegStartMenuInternet;
227
228  // Relative path of Classes registry entry under which file associations
229  // are added on Windows.
230  static const wchar_t* kRegClasses;
231
232  // Relative path of RegisteredApplications registry entry under which
233  // we add Chrome as a Windows application
234  static const wchar_t* kRegRegisteredApplications;
235
236  // The key path and key name required to register Chrome on Windows such
237  // that it can be launched from Start->Run just by name (chrome.exe).
238  static const wchar_t* kAppPathsRegistryKey;
239  static const wchar_t* kAppPathsRegistryPathName;
240
241  // Registry path that stores url associations on Vista.
242  static const wchar_t* kRegVistaUrlPrefs;
243
244  // File extensions that Chrome registers itself as the default handler
245  // for when the user makes Chrome the default browser.
246  static const wchar_t* kDefaultFileAssociations[];
247
248  // File extensions that Chrome registers itself as being capable of
249  // handling.
250  static const wchar_t* kPotentialFileAssociations[];
251
252  // Protocols that Chrome registers itself as the default handler for
253  // when the user makes Chrome the default browser.
254  static const wchar_t* kBrowserProtocolAssociations[];
255
256  // Protocols that Chrome registers itself as being capable of handling.
257  static const wchar_t* kPotentialProtocolAssociations[];
258
259  // Registry value name that is needed for ChromeHTML ProgId
260  static const wchar_t* kRegUrlProtocol;
261
262  // Relative registry path from \Software\Classes\ChromeHTML to the ProgId
263  // Application definitions.
264  static const wchar_t* kRegApplication;
265
266  // Registry value name for the AppUserModelId of an application.
267  static const wchar_t* kRegAppUserModelId;
268
269  // Registry value name for the description of an application.
270  static const wchar_t* kRegApplicationDescription;
271
272  // Registry value name for an application's name.
273  static const wchar_t* kRegApplicationName;
274
275  // Registry value name for the path to an application's icon.
276  static const wchar_t* kRegApplicationIcon;
277
278  // Registry value name for an application's company.
279  static const wchar_t* kRegApplicationCompany;
280
281  // Relative path of ".exe" registry key.
282  static const wchar_t* kRegExePath;
283
284  // Registry value name of the open verb.
285  static const wchar_t* kRegVerbOpen;
286
287  // Registry value name of the opennewwindow verb.
288  static const wchar_t* kRegVerbOpenNewWindow;
289
290  // Registry value name of the run verb.
291  static const wchar_t* kRegVerbRun;
292
293  // Registry value name for command entries.
294  static const wchar_t* kRegCommand;
295
296  // Registry value name for the DelegateExecute verb handler.
297  static const wchar_t* kRegDelegateExecute;
298
299  // Registry value name for the OpenWithProgids entry for file associations.
300  static const wchar_t* kRegOpenWithProgids;
301
302  // Returns true if |chrome_exe| is registered in HKLM with |suffix|.
303  // Note: This only checks one deterministic key in HKLM for |chrome_exe| and
304  // doesn't otherwise validate a full Chrome install in HKLM.
305  static bool QuickIsChromeRegisteredInHKLM(BrowserDistribution* dist,
306                                            const base::string16& chrome_exe,
307                                            const base::string16& suffix);
308
309  // Returns true if the current Windows version supports the presence of
310  // shortcuts at |location|.
311  static bool ShortcutLocationIsSupported(ShellUtil::ShortcutLocation location);
312
313  // Sets |path| to the path for a shortcut at the |location| desired for the
314  // given |level| (CURRENT_USER for per-user path and SYSTEM_LEVEL for
315  // all-users path).
316  // Returns false on failure.
317  static bool GetShortcutPath(ShellUtil::ShortcutLocation location,
318                              BrowserDistribution* dist,
319                              ShellChange level,
320                              base::FilePath* path);
321
322  // Updates shortcut in |location| (or creates it if |options| specify
323  // SHELL_SHORTCUT_CREATE_ALWAYS).
324  // |dist| gives the type of browser distribution currently in use.
325  // |properties| and |operation| affect this method as described on their
326  // invidividual definitions above.
327  // |location| may be one of SHORTCUT_LOCATION_DESKTOP,
328  // SHORTCUT_LOCATION_QUICK_LAUNCH, SHORTCUT_LOCATION_START_MENU_ROOT,
329  // SHORTCUT_LOCATION_START_MENU_CHROME_DIR, or
330  // SHORTCUT_LOCATION_START_MENU_CHROME_APPS_DIR.
331  static bool CreateOrUpdateShortcut(
332      ShellUtil::ShortcutLocation location,
333      BrowserDistribution* dist,
334      const ShellUtil::ShortcutProperties& properties,
335      ShellUtil::ShortcutOperation operation);
336
337  // Returns the string "|icon_path|,|icon_index|" (see, for example,
338  // http://msdn.microsoft.com/library/windows/desktop/dd391573.aspx).
339  static base::string16 FormatIconLocation(const base::string16& icon_path,
340                                           int icon_index);
341
342  // This method returns the command to open URLs/files using chrome. Typically
343  // this command is written to the registry under shell\open\command key.
344  // |chrome_exe|: the full path to chrome.exe
345  static base::string16 GetChromeShellOpenCmd(const base::string16& chrome_exe);
346
347  // This method returns the command to be called by the DelegateExecute verb
348  // handler to launch chrome on Windows 8. Typically this command is written to
349  // the registry under the HKCR\Chrome\.exe\shell\(open|run)\command key.
350  // |chrome_exe|: the full path to chrome.exe
351  static base::string16 GetChromeDelegateCommand(
352      const base::string16& chrome_exe);
353
354  // Gets a mapping of all registered browser names (excluding browsers in the
355  // |dist| distribution) and their reinstall command (which usually sets
356  // browser as default).
357  // Given browsers can be registered in HKCU (as of Win7) and/or in HKLM, this
358  // method looks in both and gives precedence to values in HKCU as per the msdn
359  // standard: http://goo.gl/xjczJ.
360  static void GetRegisteredBrowsers(
361      BrowserDistribution* dist,
362      std::map<base::string16, base::string16>* browsers);
363
364  // Returns the suffix this user's Chrome install is registered with.
365  // Always returns the empty string on system-level installs.
366  //
367  // This method is meant for external methods which need to know the suffix of
368  // the current install at run-time, not for install-time decisions.
369  // There are no guarantees that this suffix will not change later:
370  // (e.g. if two user-level installs were previously installed in parallel on
371  // the same machine, both without admin rights and with no user-level install
372  // having claimed the non-suffixed HKLM registrations, they both have no
373  // suffix in their progId entries (as per the old suffix rules). If they were
374  // to both fully register (i.e. click "Make Chrome Default" and go through
375  // UAC; or upgrade to Win8 and get the automatic no UAC full registration)
376  // they would then both get a suffixed registration as per the new suffix
377  // rules).
378  //
379  // |chrome_exe| The path to the currently installed (or running) chrome.exe.
380  static base::string16 GetCurrentInstallationSuffix(
381      BrowserDistribution* dist,
382      const base::string16& chrome_exe);
383
384  // Returns the application name of the program under |dist|.
385  // This application name will be suffixed as is appropriate for the current
386  // install.
387  // This is the name that is registered with Default Programs on Windows and
388  // that should thus be used to "make chrome default" and such.
389  static base::string16 GetApplicationName(BrowserDistribution* dist,
390                                           const base::string16& chrome_exe);
391
392  // Returns the AppUserModelId for |dist|. This identifier is unconditionally
393  // suffixed with a unique id for this user on user-level installs (in contrast
394  // to other registration entries which are suffixed as described in
395  // GetCurrentInstallationSuffix() above).
396  static base::string16 GetBrowserModelId(BrowserDistribution* dist,
397                                          bool is_per_user_install);
398
399  // Returns an AppUserModelId composed of each member of |components| separated
400  // by dots.
401  // The returned appid is guaranteed to be no longer than
402  // chrome::kMaxAppModelIdLength (some of the components might have been
403  // shortened to enforce this).
404  static base::string16 BuildAppModelId(
405      const std::vector<base::string16>& components);
406
407  // Returns true if Chrome can make itself the default browser without relying
408  // on the Windows shell to prompt the user. This is the case for versions of
409  // Windows prior to Windows 8.
410  static bool CanMakeChromeDefaultUnattended();
411
412  // Returns the DefaultState of Chrome for HTTP and HTTPS.
413  static DefaultState GetChromeDefaultState();
414
415  // Returns the DefaultState of the Chrome instance with the specified path
416  // for HTTP and HTTPs.
417  static DefaultState GetChromeDefaultStateFromPath(
418      const base::FilePath& chrome_exe);
419
420  // Returns the DefaultState of Chrome for |protocol|.
421  static DefaultState GetChromeDefaultProtocolClientState(
422      const base::string16& protocol);
423
424  // Make Chrome the default browser. This function works by going through
425  // the url protocols and file associations that are related to general
426  // browsing, e.g. http, https, .html etc., and requesting to become the
427  // default handler for each. If any of these fails the operation will return
428  // false to indicate failure, which is consistent with the return value of
429  // ShellIntegration::GetDefaultBrowser.
430  //
431  // In the case of failure any successful changes will be left, however no
432  // more changes will be attempted.
433  // TODO(benwells): Attempt to undo any changes that were successfully made.
434  // http://crbug.com/83970
435  //
436  // shell_change: Defined whether to register as default browser at system
437  //               level or user level. If value has ShellChange::SYSTEM_LEVEL
438  //               we should be running as admin user.
439  // chrome_exe: The chrome.exe path to register as default browser.
440  // elevate_if_not_admin: On Vista if user is not admin, try to elevate for
441  //                       Chrome registration.
442  static bool MakeChromeDefault(BrowserDistribution* dist,
443                                int shell_change,
444                                const base::string16& chrome_exe,
445                                bool elevate_if_not_admin);
446
447  // Shows and waits for the Windows 8 "How do you want to open webpages?"
448  // dialog if Chrome is not already the default HTTP/HTTPS handler. Also does
449  // XP-era registrations if Chrome is chosen or was already the default. Do
450  // not use on pre-Win8 OSes.
451  //
452  // |dist| gives the type of browser distribution currently in use.
453  // |chrome_exe| The chrome.exe path to register as default browser.
454  static bool ShowMakeChromeDefaultSystemUI(BrowserDistribution* dist,
455                                            const base::string16& chrome_exe);
456
457  // Make Chrome the default application for a protocol.
458  // chrome_exe: The chrome.exe path to register as default browser.
459  // protocol: The protocol to register as the default handler for.
460  static bool MakeChromeDefaultProtocolClient(BrowserDistribution* dist,
461                                              const base::string16& chrome_exe,
462                                              const base::string16& protocol);
463
464  // Shows and waits for the Windows 8 "How do you want to open links of this
465  // type?" dialog if Chrome is not already the default |protocol|
466  // handler. Also does XP-era registrations if Chrome is chosen or was already
467  // the default for |protocol|. Do not use on pre-Win8 OSes.
468  //
469  // |dist| gives the type of browser distribution currently in use.
470  // |chrome_exe| The chrome.exe path to register as default browser.
471  // |protocol| is the protocol being registered.
472  static bool ShowMakeChromeDefaultProtocolClientSystemUI(
473      BrowserDistribution* dist,
474      const base::string16& chrome_exe,
475      const base::string16& protocol);
476
477  // Registers Chrome as a potential default browser and handler for filetypes
478  // and protocols.
479  // If Chrome is already registered, this method is a no-op.
480  // This method requires write access to HKLM (prior to Win8) so is just a
481  // best effort deal.
482  // If write to HKLM is required, but fails, and:
483  // - |elevate_if_not_admin| is true (and OS is Vista or above):
484  //   tries to launch setup.exe with admin priviledges (by prompting the user
485  //   with a UAC) to do these tasks.
486  // - |elevate_if_not_admin| is false (or OS is XP):
487  //   adds the ProgId entries to HKCU. These entries will not make Chrome show
488  //   in Default Programs but they are still useful because Chrome can be
489  //   registered to run when the user clicks on an http link or an html file.
490  //
491  // |chrome_exe| full path to chrome.exe.
492  // |unique_suffix| Optional input. If given, this function appends the value
493  // to default browser entries names that it creates in the registry.
494  // Currently, this is only used to continue an install with the same suffix
495  // when elevating and calling setup.exe with admin privileges as described
496  // above.
497  // |elevate_if_not_admin| if true will make this method try alternate methods
498  // as described above. This should only be true when following a user action
499  // (e.g. "Make Chrome Default") as it allows this method to UAC.
500  //
501  // Returns true if Chrome is successfully registered (or already registered).
502  static bool RegisterChromeBrowser(BrowserDistribution* dist,
503                                    const base::string16& chrome_exe,
504                                    const base::string16& unique_suffix,
505                                    bool elevate_if_not_admin);
506
507  // This method declares to Windows that Chrome is capable of handling the
508  // given protocol. This function will call the RegisterChromeBrowser function
509  // to register with Windows as capable of handling the protocol, if it isn't
510  // currently registered as capable.
511  // Declaring the capability of handling a protocol is necessary to register
512  // as the default handler for the protocol in Vista and later versions of
513  // Windows.
514  //
515  // If called by the browser and elevation is required, it will elevate by
516  // calling setup.exe which will again call this function with elevate false.
517  //
518  // |chrome_exe| full path to chrome.exe.
519  // |unique_suffix| Optional input. If given, this function appends the value
520  // to default browser entries names that it creates in the registry.
521  // |protocol| The protocol to register as being capable of handling.s
522  // |elevate_if_not_admin| if true will make this method try alternate methods
523  // as described above.
524  static bool RegisterChromeForProtocol(BrowserDistribution* dist,
525                                        const base::string16& chrome_exe,
526                                        const base::string16& unique_suffix,
527                                        const base::string16& protocol,
528                                        bool elevate_if_not_admin);
529
530  // Removes installed shortcut(s) at |location|.
531  // |level|: CURRENT_USER to remove per-user shortcuts, or SYSTEM_LEVEL to
532  // remove all-users shortcuts.
533  // |target_exe|: Shortcut target exe; shortcuts will only be deleted when
534  // their target is |target_exe|.
535  // If |location| is a Chrome-specific folder, it will be deleted as well.
536  // Returns true if all shortcuts pointing to |target_exe| are successfully
537  // deleted, including the case where no such shortcuts are found.
538  static bool RemoveShortcuts(ShellUtil::ShortcutLocation location,
539                              BrowserDistribution* dist,
540                              ShellChange level,
541                              const base::FilePath& target_exe);
542
543  // Updates the target of all shortcuts in |location| that satisfy the
544  // following:
545  // - the shortcut's original target is |old_target_exe|,
546  // - the original arguments are non-empty.
547  // If the shortcut's icon points to |old_target_exe|, then it also gets
548  // redirected to |new_target_exe|.
549  // Returns true if all updates to matching shortcuts are successful, including
550  // the vacuous case where no matching shortcuts are found.
551  static bool RetargetShortcutsWithArgs(
552      ShellUtil::ShortcutLocation location,
553      BrowserDistribution* dist,
554      ShellChange level,
555      const base::FilePath& old_target_exe,
556      const base::FilePath& new_target_exe);
557
558  typedef base::RefCountedData<base::CancellationFlag> SharedCancellationFlag;
559
560  // Appends Chrome shortcuts with non-whitelisted arguments to |shortcuts| if
561  // not NULL. If |do_removal|, also removes non-whitelisted arguments from
562  // those shortcuts. This method will abort and return false if |cancel| is
563  // non-NULL and gets set at any point during this call.
564  static bool ShortcutListMaybeRemoveUnknownArgs(
565      ShellUtil::ShortcutLocation location,
566      BrowserDistribution* dist,
567      ShellChange level,
568      const base::FilePath& chrome_exe,
569      bool do_removal,
570      const scoped_refptr<SharedCancellationFlag>& cancel,
571      std::vector<std::pair<base::FilePath, base::string16> >* shortcuts);
572
573  // Sets |suffix| to the base 32 encoding of the md5 hash of this user's sid
574  // preceded by a dot.
575  // This is guaranteed to be unique on the machine and 27 characters long
576  // (including the '.').
577  // This suffix is then meant to be added to all registration that may conflict
578  // with another user-level Chrome install.
579  // Note that prior to Chrome 21, the suffix registered used to be the user's
580  // username (see GetOldUserSpecificRegistrySuffix() below). We still honor old
581  // installs registered that way, but it was wrong because some of the
582  // characters allowed in a username are not allowed in a ProgId.
583  // Returns true unless the OS call to retrieve the username fails.
584  // NOTE: Only the installer should use this suffix directly. Other callers
585  // should call GetCurrentInstallationSuffix().
586  static bool GetUserSpecificRegistrySuffix(base::string16* suffix);
587
588  // Sets |suffix| to this user's username preceded by a dot. This suffix should
589  // only be used to support legacy installs that used this suffixing
590  // style.
591  // Returns true unless the OS call to retrieve the username fails.
592  // NOTE: Only the installer should use this suffix directly. Other callers
593  // should call GetCurrentInstallationSuffix().
594  static bool GetOldUserSpecificRegistrySuffix(base::string16* suffix);
595
596  // Returns the base32 encoding (using the [A-Z2-7] alphabet) of |bytes|.
597  // |size| is the length of |bytes|.
598  // Note: This method does not suffix the output with '=' signs as technically
599  // required by the base32 standard for inputs that aren't a multiple of 5
600  // bytes.
601  static base::string16 ByteArrayToBase32(const uint8* bytes, size_t size);
602
603 private:
604  DISALLOW_COPY_AND_ASSIGN(ShellUtil);
605};
606
607
608#endif  // CHROME_INSTALLER_UTIL_SHELL_UTIL_H_
609