Adds the 6-month flag functionality back into the criteria checker,...

chrome/installer/gcapi/gcapi.cc

Index: chrome/installer/gcapi/gcapi.cc
===================================================================
--- chrome/installer/gcapi/gcapi.cc	(revision 8931)
+++ chrome/installer/gcapi/gcapi.cc	(working copy)
@@ -1,291 +1,444 @@
-// Copyright (c) 2006-2008 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 "chrome/installer/gcapi/gcapi.h"
-
-#include <atlbase.h>
-#include <atlcom.h>
-#include <windows.h>
-#include <sddl.h>
-#include <stdlib.h>
-#include <strsafe.h>
-#include <tlhelp32.h>
-
-#include "google_update_idl.h"
-
-namespace {
-
-const wchar_t kChromeRegClientsKey[] = L"Software\\Google\\Update\\Clients\\{8A69D345-D564-463c-AFF1-A69D9E530F96}";
-const wchar_t kChromeRegClientStateKey[] = L"Software\\Google\\Update\\ClientState\\{8A69D345-D564-463c-AFF1-A69D9E530F96}";
-const wchar_t kChromeRegLaunchCmd[] = L"InstallerSuccessLaunchCmdLine";
-const wchar_t kChromeRegLastLaunchCmd[] = L"LastInstallerSuccessLaunchCmdLine";
-const wchar_t kChromeRegVersion[] = L"pv";
-
-// Helper function to read a value from registry. Returns true if value
-// is read successfully and stored in parameter value. Returns false otherwise.
-bool ReadValueFromRegistry(HKEY root_key, const wchar_t *sub_key,
-                           const wchar_t *value_name, wchar_t *value,
-                           size_t *size) {
-  HKEY key;
-  if ((::RegOpenKeyEx(root_key, sub_key, NULL,
-                      KEY_READ, &key) == ERROR_SUCCESS) &&
-      (::RegQueryValueEx(key, value_name, NULL, NULL,
-                         reinterpret_cast<LPBYTE>(value),
-                         reinterpret_cast<LPDWORD>(size)) == ERROR_SUCCESS)) {
-    ::RegCloseKey(key);
-    return true;
-  }
-  return false;
-}
-
-bool IsChromeInstalled(HKEY root_key) {
-  wchar_t version[64];
-  size_t size = _countof(version);
-  if (ReadValueFromRegistry(root_key, kChromeRegClientsKey, kChromeRegVersion,
-                            version, &size))
-    return true;
-  return false;
-}
-
-bool IsWinXPSp1OrLater(bool* is_vista_or_later) {
-  OSVERSIONINFOEX osviex = { sizeof(OSVERSIONINFOEX) };
-  int r = ::GetVersionEx((LPOSVERSIONINFO)&osviex);
-  // If this failed we're on Win9X or a pre NT4SP6 OS
-  if (!r)
-    return false;
-
-  if (osviex.dwMajorVersion < 5)
-    return false;
-
-  if (osviex.dwMajorVersion > 5) {
-    *is_vista_or_later = true;
-    return true;    // way beyond Windows XP;
-  }
-
-  if (osviex.dwMinorVersion >= 1 && osviex.wServicePackMajor >= 1)
-    return true;    // Windows XP SP1 or better
-
-  return false;     // Windows 2000, WinXP no Service Pack
-}
-
-// Note this function should not be called on old Windows versions where these
-// Windows API are not available. We always invoke this function after checking
-// that current OS is Vista or later.
-bool VerifyAdminGroup() {
-  SID_IDENTIFIER_AUTHORITY NtAuthority = SECURITY_NT_AUTHORITY;
-  PSID Group;
-  BOOL check = ::AllocateAndInitializeSid(&NtAuthority, 2,
-                                          SECURITY_BUILTIN_DOMAIN_RID,
-                                          DOMAIN_ALIAS_RID_ADMINS, 0, 0, 0,
-                                          0, 0, 0,
-                                          &Group); 
-  if (check) {
-    if (!::CheckTokenMembership(NULL, Group, &check))
-      check = FALSE;
-  }
-  ::FreeSid(Group); 
-  return (check == TRUE);
-}
-
-bool VerifyHKLMAccess(const wchar_t* sub_key) {
-  HKEY root = HKEY_LOCAL_MACHINE;
-  wchar_t str[] = L"test";
-  bool result = false;
-  DWORD disposition = 0;
-  HKEY key = NULL;
-
-  if (::RegCreateKeyEx(root, sub_key, 0, NULL,
-                       REG_OPTION_NON_VOLATILE, KEY_READ | KEY_WRITE, NULL,
-                       &key, &disposition) == ERROR_SUCCESS) {
-    if (::RegSetValueEx(key, str, 0, REG_SZ, (LPBYTE)str,
-        (DWORD)lstrlen(str)) == ERROR_SUCCESS) {
-      result = true;
-      RegDeleteValue(key, str);
-    }
-
-    //  If we create the main key, delete the entire key.
-    if (disposition == REG_CREATED_NEW_KEY)
-      RegDeleteKey(key, NULL);
-
-    RegCloseKey(key);
-  }
-
-  return result;
-}
-
-bool IsRunningElevated() {
-  // This method should be called only for Vista or later.
-  bool is_vista_or_later = false;
-  IsWinXPSp1OrLater(&is_vista_or_later);
-  if (!is_vista_or_later || !VerifyAdminGroup())
-    return false;
-
-  HANDLE process_token;
-  if (!::OpenProcessToken(GetCurrentProcess(), TOKEN_QUERY, &process_token))
-    return false;
-
-  TOKEN_ELEVATION_TYPE elevation_type = TokenElevationTypeDefault;
-  DWORD size_returned = 0;
-  if (!::GetTokenInformation(process_token, TokenElevationType,
-                             &elevation_type, sizeof(elevation_type),
-                             &size_returned)) {
-    ::CloseHandle(process_token);
-    return false;
-  }
-
-  ::CloseHandle(process_token);
-  return (elevation_type == TokenElevationTypeFull);
-}
-
-bool GetUserIdForProcess(size_t pid, wchar_t** user_sid) {
-  HANDLE process_handle = ::OpenProcess(PROCESS_QUERY_INFORMATION, TRUE, pid);
-  if (process_handle == NULL)
-    return false;
-
-  HANDLE process_token;
-  bool result = false;
-  if (::OpenProcessToken(process_handle, TOKEN_QUERY, &process_token)) {
-    DWORD size = 0;
-    ::GetTokenInformation(process_token, TokenUser, NULL, 0, &size);
-    if (::GetLastError() == ERROR_INSUFFICIENT_BUFFER ||
-        ::GetLastError() == ERROR_SUCCESS) {
-      DWORD actual_size = 0;
-      BYTE* token_user = new BYTE[size];
-      if ((::GetTokenInformation(process_token, TokenUser, token_user, size,
-                                &actual_size)) &&
-          (actual_size <= size)) {
-        PSID sid = reinterpret_cast<TOKEN_USER*>(token_user)->User.Sid;
-        if (::ConvertSidToStringSid(sid, user_sid))
-          result = true;
-      }
-      delete[] token_user;
-    }
-    ::CloseHandle(process_token);
-  }
-  ::CloseHandle(process_handle);
-  return result;
-}
-}  // namespace
-
-#pragma comment(linker, "/EXPORT:GoogleChromeCompatibilityCheck=_GoogleChromeCompatibilityCheck@4,PRIVATE")
-DLLEXPORT BOOL __stdcall GoogleChromeCompatibilityCheck(DWORD *reasons) {
-  DWORD local_reasons = 0;
-
-  bool is_vista_or_later = false;
-  // System requirements?
-  if (!IsWinXPSp1OrLater(&is_vista_or_later))
-    local_reasons |= GCCC_ERROR_OSNOTSUPPORTED;
-
-  if (IsChromeInstalled(HKEY_LOCAL_MACHINE))
-    local_reasons |= GCCC_ERROR_SYSTEMLEVELALREADYPRESENT;
-
-  if (IsChromeInstalled(HKEY_CURRENT_USER))
-    local_reasons |= GCCC_ERROR_USERLEVELALREADYPRESENT;
-
-  if (!VerifyHKLMAccess(kChromeRegClientsKey)) {
-    local_reasons |= GCCC_ERROR_ACCESSDENIED;
-  } else if (is_vista_or_later && !VerifyAdminGroup()) {
-    // For Vista or later check for elevation since even for admin user we could
-    // be running in non-elevated mode. We require integrity level High.
-    local_reasons |= GCCC_ERROR_INTEGRITYLEVEL;
-  }
-
-  // Done. Copy/return results.
-  if (reasons != NULL)
-    *reasons = local_reasons;
-
-  return (*reasons == 0);
-}
-
-#pragma comment(linker, "/EXPORT:LaunchGoogleChrome=_LaunchGoogleChrome@0,PRIVATE")
-DLLEXPORT BOOL __stdcall LaunchGoogleChrome() {
-  wchar_t launch_cmd[MAX_PATH];
-  size_t size = _countof(launch_cmd);
-  if (!ReadValueFromRegistry(HKEY_LOCAL_MACHINE, kChromeRegClientStateKey,
-                             kChromeRegLastLaunchCmd, launch_cmd, &size)) {
-    size = _countof(launch_cmd);
-    if (!ReadValueFromRegistry(HKEY_LOCAL_MACHINE, kChromeRegClientStateKey,
-                               kChromeRegLaunchCmd, launch_cmd, &size)) {
-      return false;
-    }
-  }
-
-  HRESULT hr = ::CoInitializeEx(NULL, COINIT_APARTMENTTHREADED);
-  if (hr != S_OK) {
-    if (hr == S_FALSE)
-      ::CoUninitialize();
-    return false;
-  }
-
-  if (::CoInitializeSecurity(NULL, -1, NULL, NULL,
-                             RPC_C_AUTHN_LEVEL_PKT_PRIVACY,
-                             RPC_C_IMP_LEVEL_IDENTIFY, NULL,
-                             EOAC_DYNAMIC_CLOAKING, NULL) != S_OK) {
-    ::CoUninitialize();
-    return false;
-  }
-
-  bool impersonation_success = false;
-  if (IsRunningElevated()) {
-    wchar_t* curr_proc_sid;
-    if (!GetUserIdForProcess(GetCurrentProcessId(), &curr_proc_sid)) {
-      ::CoUninitialize();
-      return false;
-    }
-
-    DWORD pid = 0;
-    ::GetWindowThreadProcessId(::GetShellWindow(), &pid);
-    if (pid <= 0) {
-      ::LocalFree(curr_proc_sid);
-      ::CoUninitialize();
-      return false;
-    }
-
-    wchar_t* exp_proc_sid;
-    if (GetUserIdForProcess(pid, &exp_proc_sid)) {
-      if (_wcsicmp(curr_proc_sid, exp_proc_sid) == 0) {
-        HANDLE process_handle = ::OpenProcess(
-            PROCESS_DUP_HANDLE | PROCESS_QUERY_INFORMATION, TRUE, pid);
-        if (process_handle != NULL) {
-          HANDLE process_token;
-          HANDLE user_token;
-          if (::OpenProcessToken(process_handle, TOKEN_DUPLICATE | TOKEN_QUERY,
-                                 &process_token) &&
-              ::DuplicateTokenEx(process_token,
-                                 TOKEN_IMPERSONATE | TOKEN_QUERY |
-                                     TOKEN_ASSIGN_PRIMARY | TOKEN_DUPLICATE,
-                                 NULL, SecurityImpersonation,
-                                 TokenPrimary, &user_token) &&
-              (::ImpersonateLoggedOnUser(user_token) != 0)) {
-            impersonation_success = true;
-          }
-          ::CloseHandle(user_token);
-          ::CloseHandle(process_token);
-          ::CloseHandle(process_handle);
-        }
-      }
-      ::LocalFree(exp_proc_sid);
-    }
-
-    ::LocalFree(curr_proc_sid);
-    if (!impersonation_success) {
-      ::CoUninitialize();
-      return false;
-    }
-  }
-
-  bool ret = false;
-  CComPtr<IProcessLauncher> ipl;
-  if (!FAILED(ipl.CoCreateInstance(__uuidof(ProcessLauncherClass), NULL,
-                                   CLSCTX_LOCAL_SERVER))) {
-    if (!FAILED(ipl->LaunchCmdLine(launch_cmd)))
-      ret = true;
-    ipl.Release();
-  }
-
-  if (impersonation_success)
-    ::RevertToSelf();
-  ::CoUninitialize();
-  return ret;
-}
+// Copyright (c) 2006-2008 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 "chrome/installer/gcapi/gcapi.h"
+
+#include <atlbase.h>
+#include <atlcom.h>
+#include <windows.h>
+#include <sddl.h>
+#include <stdlib.h>
+#include <strsafe.h>
+#include <tlhelp32.h>
+
+#include "google_update_idl.h"
+
+namespace {
+
+const wchar_t kChromeRegClientsKey[] = L"Software\\Google\\Update\\Clients\\{8A69D345-D564-463c-AFF1-A69D9E530F96}";
+const wchar_t kChromeRegClientStateKey[] = L"Software\\Google\\Update\\ClientState\\{8A69D345-D564-463c-AFF1-A69D9E530F96}";
+const wchar_t kChromeRegLaunchCmd[] = L"InstallerSuccessLaunchCmdLine";
+const wchar_t kChromeRegLastLaunchCmd[] = L"LastInstallerSuccessLaunchCmdLine";
+const wchar_t kChromeRegVersion[] = L"pv";
+const wchar_t kNoChromeOfferUntil[] = L"SOFTWARE\\Google\\No Chrome Offer Until";
+
+// Remove any registry key with non-numeric value or with the numeric value
+// equal or less than today's date represented in YYYYMMDD form.
+void CleanUpRegistryValues() {
+  HKEY key = NULL;
+  if (::RegOpenKeyEx(HKEY_LOCAL_MACHINE, kNoChromeOfferUntil,
+                     0, KEY_ALL_ACCESS, &key) != ERROR_SUCCESS)
+    return;
+
+  DWORD index = 0;
+  wchar_t value_name[260];
+  DWORD value_name_len = _countof(value_name);
+  DWORD value_type = REG_DWORD;
+  DWORD value_data = 0;
+  DWORD value_len = sizeof(DWORD);
+
+  // First, remove any value whose type is not DWORD.
+  while (::RegEnumValue(key, index, value_name, &value_name_len, NULL, 
+                        &value_type, NULL, &value_len) == ERROR_SUCCESS) {
+    if (value_type == REG_DWORD)
+      index++;
+    else
+      ::RegDeleteValue(key, value_name);
+
+    value_name_len = _countof(value_name);
+    value_type = REG_DWORD;
+    value_len = sizeof(DWORD);
+  }
+
+  // Get today's date, and format it as YYYYMMDD numeric value.
+  SYSTEMTIME now;
+  ::GetLocalTime(&now);
+  DWORD expiration_date = now.wYear * 10000 + now.wMonth * 100 + now.wDay;
+
+  // Remove any DWORD value smaller than the number represent the
+  // expiration date (YYYYMMDD).
+  index = 0;
+  while (::RegEnumValue(key, index, value_name, &value_name_len, NULL, 
+                        &value_type, (LPBYTE) &value_data, 
+                        &value_len) == ERROR_SUCCESS) {
+    if (value_type == REG_DWORD && value_data > expiration_date)
+      index++;  // move on to next value.
+    else
+      ::RegDeleteValue(key, value_name);  // delete this value.
+
+    value_name_len = _countof(value_name);
+    value_type = REG_DWORD;
+    value_data = 0;
+    value_len = sizeof(DWORD);
+  }
+
+  ::RegCloseKey(key);
+}
+
+// Return the company name specified in the file version info resource.
+bool GetCompanyName(const wchar_t* filename, wchar_t* buffer, DWORD out_len) {
+  wchar_t file_version_info[8192];
+  DWORD handle = 0;
+  DWORD buffer_size = 0;
+
+  buffer_size = ::GetFileVersionInfoSize(filename, &handle);
+  // Cannot stats the file or our buffer size is too small (very unlikely).
+  if (buffer_size == 0 || buffer_size > _countof(file_version_info))
+    return false;
+
+  buffer_size = _countof(file_version_info);
+  memset(file_version_info, 0, buffer_size);
+  if (!::GetFileVersionInfo(filename, handle, buffer_size, file_version_info))
+    return false;
+
+  DWORD data_len = 0;
+  LPVOID data = NULL;
+  // Retrieve the language and codepage code if exists.
+  buffer_size = 0;
+  if (!::VerQueryValue(file_version_info, TEXT("\\VarFileInfo\\Translation"),
+      reinterpret_cast<LPVOID *>(&data), reinterpret_cast<UINT *>(&data_len)))
+    return false;
+  if (data_len != 4)
+    return false;
+
+  wchar_t info_name[256];
+  DWORD lang = 0;
+  // Formulate the string to retrieve the company name of the specific
+  // language codepage.
+  memcpy(&lang, data, 4);
+  ::StringCchPrintf(info_name, _countof(info_name),
+      L"\\StringFileInfo\\%02X%02X%02X%02X\\CompanyName",
+      (lang & 0xff00)>>8, (lang & 0xff), (lang & 0xff000000)>>24,
+      (lang & 0xff0000)>>16);
+
+  data_len = 0;
+  if (!::VerQueryValue(file_version_info, info_name,
+      reinterpret_cast<LPVOID *>(&data), reinterpret_cast<UINT *>(&data_len)))
+    return false;
+  if (data_len <= 0 || data_len >= out_len)
+    return false;
+
+  memset(buffer, 0, out_len);
+  ::StringCchCopyN(buffer, out_len, (const wchar_t*)data, data_len);
+  return true;
+}
+
+// Return true if we can re-offer Chrome; false, otherwise.
+// Each partner can only offer Chrome once every six months.
+bool CanReOfferChrome(BOOL set_flag) {
+  wchar_t filename[MAX_PATH+1];
+  wchar_t company[MAX_PATH];
+
+  // If we cannot retrieve the version info of the executable or company
+  // name, we allow the Chrome to be offered because there is no past
+  // history to be found.
+  if (::GetModuleFileName(NULL, filename, MAX_PATH) == 0)
+    return true;
+  if (!GetCompanyName(filename, company, sizeof(company)))
+    return true;
+
+  bool can_re_offer = true;
+  DWORD disposition = 0;
+  HKEY key = NULL;
+  if (::RegCreateKeyEx(HKEY_LOCAL_MACHINE, kNoChromeOfferUntil,
+      0, NULL, REG_OPTION_NON_VOLATILE, KEY_READ | KEY_WRITE,
+      NULL, &key, &disposition) == ERROR_SUCCESS) {
+    // Cannot re-offer, if the timer already exists and is not expired yet.
+    if (::RegQueryValueEx(key, company, 0, 0, 0, 0) == ERROR_SUCCESS) {
+      // The expired timers were already removed in CleanUpRegistryValues.
+      // So if the key is not found, we can offer the Chrome.
+      can_re_offer = false;
+    } else if (set_flag) {
+      // Set expiration date for offer as six months from today,
+      // represented as a YYYYMMDD numeric value.
+      SYSTEMTIME timer;
+      ::GetLocalTime(&timer);
+      timer.wMonth = timer.wMonth + 6;
+      if (timer.wMonth > 12) {
+        timer.wMonth = timer.wMonth - 12;
+        timer.wYear = timer.wYear + 1;
+      }
+      DWORD value = timer.wYear * 10000 + timer.wMonth * 100 + timer.wDay;
+      ::RegSetValueEx(key, company, 0, REG_DWORD, (LPBYTE)&value, sizeof(DWORD));
+    }
+
+    ::RegCloseKey(key);
+  }
+
+  return can_re_offer;
+}
+
+// Helper function to read a value from registry. Returns true if value
+// is read successfully and stored in parameter value. Returns false otherwise.
+bool ReadValueFromRegistry(HKEY root_key, const wchar_t *sub_key,
+                           const wchar_t *value_name, wchar_t *value,
+                           size_t *size) {
+  HKEY key;
+  if ((::RegOpenKeyEx(root_key, sub_key, NULL,
+                      KEY_READ, &key) == ERROR_SUCCESS) &&
+      (::RegQueryValueEx(key, value_name, NULL, NULL,
+                         reinterpret_cast<LPBYTE>(value),
+                         reinterpret_cast<LPDWORD>(size)) == ERROR_SUCCESS)) {
+    ::RegCloseKey(key);
+    return true;
+  }
+  return false;
+}
+
+bool IsChromeInstalled(HKEY root_key) {
+  wchar_t version[64];
+  size_t size = _countof(version);
+  if (ReadValueFromRegistry(root_key, kChromeRegClientsKey, kChromeRegVersion,
+                            version, &size))
+    return true;
+  return false;
+}
+
+bool IsWinXPSp1OrLater(bool* is_vista_or_later) {
+  OSVERSIONINFOEX osviex = { sizeof(OSVERSIONINFOEX) };
+  int r = ::GetVersionEx((LPOSVERSIONINFO)&osviex);
+  // If this failed we're on Win9X or a pre NT4SP6 OS.
+  if (!r)
+    return false;
+
+  if (osviex.dwMajorVersion < 5)
+    return false;
+
+  if (osviex.dwMajorVersion > 5) {
+    *is_vista_or_later = true;
+    return true;    // way beyond Windows XP;
+  }
+
+  if (osviex.dwMinorVersion >= 1 && osviex.wServicePackMajor >= 1)
+    return true;    // Windows XP SP1 or better.
+
+  return false;     // Windows 2000, WinXP no Service Pack.
+}
+
+// Note this function should not be called on old Windows versions where these
+// Windows API are not available. We always invoke this function after checking
+// that current OS is Vista or later.
+bool VerifyAdminGroup() {
+  SID_IDENTIFIER_AUTHORITY NtAuthority = SECURITY_NT_AUTHORITY;
+  PSID Group;
+  BOOL check = ::AllocateAndInitializeSid(&NtAuthority, 2,
+                                          SECURITY_BUILTIN_DOMAIN_RID,
+                                          DOMAIN_ALIAS_RID_ADMINS, 0, 0, 0,
+                                          0, 0, 0,
+                                          &Group); 
+  if (check) {
+    if (!::CheckTokenMembership(NULL, Group, &check))
+      check = FALSE;
+  }
+  ::FreeSid(Group); 
+  return (check == TRUE);
+}
+
+bool VerifyHKLMAccess(const wchar_t* sub_key) {
+  HKEY root = HKEY_LOCAL_MACHINE;
+  wchar_t str[] = L"test";
+  bool result = false;
+  DWORD disposition = 0;
+  HKEY key = NULL;
+
+  if (::RegCreateKeyEx(root, sub_key, 0, NULL,
+                       REG_OPTION_NON_VOLATILE, KEY_READ | KEY_WRITE, NULL,
+                       &key, &disposition) == ERROR_SUCCESS) {
+    if (::RegSetValueEx(key, str, 0, REG_SZ, (LPBYTE)str,
+        (DWORD)lstrlen(str)) == ERROR_SUCCESS) {
+      result = true;
+      RegDeleteValue(key, str);
+    }
+
+    //  If we create the main key, delete the entire key.
+    if (disposition == REG_CREATED_NEW_KEY)
+      RegDeleteKey(key, NULL);
+
+    RegCloseKey(key);
+  }
+
+  return result;
+}
+
+bool IsRunningElevated() {
+  // This method should be called only for Vista or later.
+  bool is_vista_or_later = false;
+  IsWinXPSp1OrLater(&is_vista_or_later);
+  if (!is_vista_or_later || !VerifyAdminGroup())
+    return false;
+
+  HANDLE process_token;
+  if (!::OpenProcessToken(GetCurrentProcess(), TOKEN_QUERY, &process_token))
+    return false;
+
+  TOKEN_ELEVATION_TYPE elevation_type = TokenElevationTypeDefault;
+  DWORD size_returned = 0;
+  if (!::GetTokenInformation(process_token, TokenElevationType,
+                             &elevation_type, sizeof(elevation_type),
+                             &size_returned)) {
+    ::CloseHandle(process_token);
+    return false;
+  }
+
+  ::CloseHandle(process_token);
+  return (elevation_type == TokenElevationTypeFull);
+}
+
+bool GetUserIdForProcess(size_t pid, wchar_t** user_sid) {
+  HANDLE process_handle = ::OpenProcess(PROCESS_QUERY_INFORMATION, TRUE, pid);
+  if (process_handle == NULL)
+    return false;
+
+  HANDLE process_token;
+  bool result = false;
+  if (::OpenProcessToken(process_handle, TOKEN_QUERY, &process_token)) {
+    DWORD size = 0;
+    ::GetTokenInformation(process_token, TokenUser, NULL, 0, &size);
+    if (::GetLastError() == ERROR_INSUFFICIENT_BUFFER ||
+        ::GetLastError() == ERROR_SUCCESS) {
+      DWORD actual_size = 0;
+      BYTE* token_user = new BYTE[size];
+      if ((::GetTokenInformation(process_token, TokenUser, token_user, size,
+                                &actual_size)) &&
+          (actual_size <= size)) {
+        PSID sid = reinterpret_cast<TOKEN_USER*>(token_user)->User.Sid;
+        if (::ConvertSidToStringSid(sid, user_sid))
+          result = true;
+      }
+      delete[] token_user;
+    }
+    ::CloseHandle(process_token);
+  }
+  ::CloseHandle(process_handle);
+  return result;
+}
+}  // namespace
+
+#pragma comment(linker, "/EXPORT:GoogleChromeCompatibilityCheck=_GoogleChromeCompatibilityCheck@8,PRIVATE")
+DLLEXPORT BOOL __stdcall GoogleChromeCompatibilityCheck(BOOL set_flag, DWORD *reasons) {
+  DWORD local_reasons = 0;
+
+  bool is_vista_or_later = false;
+  // System requirements?
+  if (!IsWinXPSp1OrLater(&is_vista_or_later))
+    local_reasons |= GCCC_ERROR_OSNOTSUPPORTED;
+
+  if (IsChromeInstalled(HKEY_LOCAL_MACHINE))
+    local_reasons |= GCCC_ERROR_SYSTEMLEVELALREADYPRESENT;
+
+  if (IsChromeInstalled(HKEY_CURRENT_USER))
+    local_reasons |= GCCC_ERROR_USERLEVELALREADYPRESENT;
+
+  if (!VerifyHKLMAccess(kChromeRegClientsKey)) {
+    local_reasons |= GCCC_ERROR_ACCESSDENIED;
+  } else if (is_vista_or_later && !VerifyAdminGroup()) {
+    // For Vista or later check for elevation since even for admin user we could
+    // be running in non-elevated mode. We require integrity level High.
+    local_reasons |= GCCC_ERROR_INTEGRITYLEVEL;
+  }
+
+   // First clean up the registry keys left over previously.
+   // Then only check whether we can re-offer, if everything else is OK.
+   CleanUpRegistryValues();	 
+   if (local_reasons == 0 && !CanReOfferChrome(set_flag))	 
+     local_reasons |= GCCC_ERROR_ALREADYOFFERED;	 
+ 
+  // Done. Copy/return results.
+  if (reasons != NULL)
+    *reasons = local_reasons;
+
+  return (*reasons == 0);
+}
+
+#pragma comment(linker, "/EXPORT:LaunchGoogleChrome=_LaunchGoogleChrome@0,PRIVATE")
+DLLEXPORT BOOL __stdcall LaunchGoogleChrome() {
+  wchar_t launch_cmd[MAX_PATH];
+  size_t size = _countof(launch_cmd);
+  if (!ReadValueFromRegistry(HKEY_LOCAL_MACHINE, kChromeRegClientStateKey,
+                             kChromeRegLastLaunchCmd, launch_cmd, &size)) {
+    size = _countof(launch_cmd);
+    if (!ReadValueFromRegistry(HKEY_LOCAL_MACHINE, kChromeRegClientStateKey,
+                               kChromeRegLaunchCmd, launch_cmd, &size)) {
+      return false;
+    }
+  }
+
+  HRESULT hr = ::CoInitializeEx(NULL, COINIT_APARTMENTTHREADED);
+  if (hr != S_OK) {
+    if (hr == S_FALSE)
+      ::CoUninitialize();
+    return false;
+  }
+
+  if (::CoInitializeSecurity(NULL, -1, NULL, NULL,
+                             RPC_C_AUTHN_LEVEL_PKT_PRIVACY,
+                             RPC_C_IMP_LEVEL_IDENTIFY, NULL,
+                             EOAC_DYNAMIC_CLOAKING, NULL) != S_OK) {
+    ::CoUninitialize();
+    return false;
+  }
+
+  bool impersonation_success = false;
+  if (IsRunningElevated()) {
+    wchar_t* curr_proc_sid;
+    if (!GetUserIdForProcess(GetCurrentProcessId(), &curr_proc_sid)) {
+      ::CoUninitialize();
+      return false;
+    }
+
+    DWORD pid = 0;
+    ::GetWindowThreadProcessId(::GetShellWindow(), &pid);
+    if (pid <= 0) {
+      ::LocalFree(curr_proc_sid);
+      ::CoUninitialize();
+      return false;
+    }
+
+    wchar_t* exp_proc_sid;
+    if (GetUserIdForProcess(pid, &exp_proc_sid)) {
+      if (_wcsicmp(curr_proc_sid, exp_proc_sid) == 0) {
+        HANDLE process_handle = ::OpenProcess(
+            PROCESS_DUP_HANDLE | PROCESS_QUERY_INFORMATION, TRUE, pid);
+        if (process_handle != NULL) {
+          HANDLE process_token;
+          HANDLE user_token;
+          if (::OpenProcessToken(process_handle, TOKEN_DUPLICATE | TOKEN_QUERY,
+                                 &process_token) &&
+              ::DuplicateTokenEx(process_token,
+                                 TOKEN_IMPERSONATE | TOKEN_QUERY |
+                                     TOKEN_ASSIGN_PRIMARY | TOKEN_DUPLICATE,
+                                 NULL, SecurityImpersonation,
+                                 TokenPrimary, &user_token) &&
+              (::ImpersonateLoggedOnUser(user_token) != 0)) {
+            impersonation_success = true;
+          }
+          ::CloseHandle(user_token);
+          ::CloseHandle(process_token);
+          ::CloseHandle(process_handle);
+        }
+      }
+      ::LocalFree(exp_proc_sid);
+    }
+
+    ::LocalFree(curr_proc_sid);
+    if (!impersonation_success) {
+      ::CoUninitialize();
+      return false;
+    }
+  }
+
+  bool ret = false;
+  CComPtr<IProcessLauncher> ipl;
+  if (!FAILED(ipl.CoCreateInstance(__uuidof(ProcessLauncherClass), NULL,
+                                   CLSCTX_LOCAL_SERVER))) {
+    if (!FAILED(ipl->LaunchCmdLine(launch_cmd)))
+      ret = true;
+    ipl.Release();
+  }
+
+  if (impersonation_success)
+    ::RevertToSelf();
+  ::CoUninitialize();
+  return ret;
+}