Use a better registration suffix that will always be unique while respecting the MSDN rules (2nd tr…

chrome/installer/util/shell_util.h

 // Copyright (c) 2012 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.
 //
 // This file declares methods that are useful for integrating Chrome in
 // Windows shell. These methods are all static and currently part of
 // ShellUtil class.
 
 #ifndef CHROME_INSTALLER_UTIL_SHELL_UTIL_H_
 #define CHROME_INSTALLER_UTIL_SHELL_UTIL_H_
 #pragma once
 
 #include <windows.h>
 
 #include <map>
 #include <vector>
 
 #include "base/basictypes.h"
+#include "base/md5.h"
 #include "base/string16.h"
 #include "chrome/installer/util/work_item_list.h"
 
 class BrowserDistribution;
 class FilePath;
 
 namespace base {
 class DictionaryValue;
 }
 
@@ skipping 207 matching lines @@
 
   // Returns the application name of the program under |dist|.
   // This application name will be suffixed as is appropriate for the current
   // install.
   // This is the name that is registered with Default Programs on Windows and
   // that should thus be used to "make chrome default" and such.
   static string16 GetApplicationName(BrowserDistribution* dist,
                                      const string16& chrome_exe);
 
   // Returns the AppUserModelId for |dist|. This identifier is unconditionally
-  // suffixed with the user id for user-level installs (in contrast to other
-  // registration entries which are suffix as described in
+  // suffixed with a unique id for this user on user-level installs (in contrast
+  // to other registration entries which are suffixed as described in
   // GetCurrentInstallationSuffix() above).
   static string16 GetBrowserModelId(BrowserDistribution* dist,
                                     const string16& chrome_exe);
 
   // Returns an AppUserModelId composed of each member of |components| separated
   // by dots.
   // The returned appid is guaranteed to be no longer than
   // chrome::kMaxAppModelIdLength (some of the components might have been
   // shortened to enforce this).
   static string16 BuildAppModelId(const std::vector<string16>& components);
@@ skipping 140 matching lines @@
   // |options|: bitfield for which the options come from ChromeShortcutOptions.
   static bool UpdateChromeShortcut(BrowserDistribution* dist,
                                    const string16& chrome_exe,
                                    const string16& shortcut,
                                    const string16& arguments,
                                    const string16& description,
                                    const string16& icon_path,
                                    int icon_index,
                                    uint32 options);
 
+  // Sets |suffix| to the base 32 encoding of the md5 hash of this user's
+  // username preceded by a dot.
+  // This is guaranteed to be unique on the machine and 27 characters long
+  // (including the '.').
+  // This suffix is then meant to be added to all registration that may conflict
+  // with another user-level Chrome install.
+  // Note that prior to Chrome 21, the suffix registered used to be the user's
+  // username (see GetOldUserSpecificRegistrySuffix() below). We still honor old
+  // installs registered that way, but it was wrong because some of the
+  // characters allowed in a username are not allowed in a ProgId.
+  // Returns true unless the OS call to retrieve the username fails.
+  // NOTE: Only the installer should use this suffix directly. Other callers
+  // should call GetCurrentInstallationSuffix().
+  static bool GetNewUserSpecificRegistrySuffix(string16* suffix);
+
+  // Sets |suffix| to this user's username preceded by a dot. This suffix is
+  // then meant to be added to all registration that may conflict with another
+  // user-level Chrome install.
+  // Returns true unless the OS call to retrieve the username fails.
+  // NOTE: Only the installer should use this suffix directly. Other callers
+  // should call GetCurrentInstallationSuffix().
+  static bool GetOldUserSpecificRegistrySuffix(string16* suffix);
+
+  // Returns the base32 encoding (using the [A-Z2-7] alphabet) of |digest|.
+  // The returned string will be exactly 26 characters in length.
+  static string16 MD5DigestToBase32(const base::MD5Digest& digest);
+
+  // Returns the base32 encoding (using the [A-Z2-7] alphabet) of |bytes|.
+  // |size| is the length of |bytes|.
+  // Note: This method does not suffix the output with '=' signs as technically
+  // required by the base32 standard for inputs that aren't a multiple of 5
+  // bits.
+  static string16 ByteArrayToBase32(const unsigned char bytes[], int size);
+
  private:
   DISALLOW_COPY_AND_ASSIGN(ShellUtil);
 };
 
 
 #endif  // CHROME_INSTALLER_UTIL_SHELL_UTIL_H_