chrome/installer/gcapi/gcapi.cc

   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 // NOTE: This code is a legacy utility API for partners to check whether
   6 //       Chrome can be installed and launched. Recent updates are being made
   7 //       to add new functionality. These updates use code from Chromium, the old
   8 //       coded against the win32 api directly. If you have an itch to shave a
   9 //       yak, feel free to re-write the old code too.
  10
  11 #include "chrome/installer/gcapi/gcapi.h"
  12
  13 #include <sddl.h>
  14 #define STRSAFE_NO_DEPRECATE
  15 #include <windows.h>
  16 #include <strsafe.h>
  17 #include <tlhelp32.h>
  18
  19 #include <cstdlib>
  20 #include <iterator>
  21 #include <limits>
  22 #include <set>
  23 #include <string>
  24
  25 #include "base/basictypes.h"
  26 #include "base/command_line.h"
  27 #include "base/files/file_path.h"
  28 #include "base/process/launch.h"
  29 #include "base/strings/string16.h"
  30 #include "base/strings/string_number_conversions.h"
  31 #include "base/strings/string_util.h"
  32 #include "base/time/time.h"
  33 #include "base/win/registry.h"
  34 #include "base/win/scoped_com_initializer.h"
  35 #include "base/win/scoped_comptr.h"
  36 #include "base/win/scoped_handle.h"
  37 #include "chrome/installer/gcapi/gcapi_omaha_experiment.h"
  38 #include "chrome/installer/gcapi/gcapi_reactivation.h"
  39 #include "chrome/installer/launcher_support/chrome_launcher_support.h"
  40 #include "chrome/installer/util/google_update_constants.h"
  41 #include "chrome/installer/util/google_update_settings.h"
  42 #include "chrome/installer/util/util_constants.h"
  43 #include "chrome/installer/util/wmi.h"
  44 #include "google_update/google_update_idl.h"
  45
  46 using base::Time;
  47 using base::TimeDelta;
  48 using base::win::RegKey;
  49 using base::win::ScopedCOMInitializer;
  50 using base::win::ScopedComPtr;
  51 using base::win::ScopedHandle;
  52
  53 namespace {
  54
  55 const wchar_t kChromeRegClientsKey[] =
  56     L"Software\\Google\\Update\\Clients\\"
  57     L"{8A69D345-D564-463c-AFF1-A69D9E530F96}";
  58 const wchar_t kChromeRegClientStateKey[] =
  59     L"Software\\Google\\Update\\ClientState\\"
  60     L"{8A69D345-D564-463c-AFF1-A69D9E530F96}";
  61
  62 const wchar_t kGCAPITempKey[] = L"Software\\Google\\GCAPITemp";
  63
  64 const wchar_t kChromeRegVersion[] = L"pv";
  65 const wchar_t kNoChromeOfferUntil[] =
  66     L"SOFTWARE\\Google\\No Chrome Offer Until";
  67
  68 const wchar_t kC1FPendingKey[] =
  69     L"Software\\Google\\Common\\Rlz\\Events\\C";
  70 const wchar_t kC1FSentKey[] =
  71     L"Software\\Google\\Common\\Rlz\\StatefulEvents\\C";
  72 const wchar_t kC1FKey[] = L"C1F";
  73
  74 const wchar_t kRelaunchBrandcodeValue[] = L"RelaunchBrandcode";
  75 const wchar_t kRelaunchAllowedAfterValue[] = L"RelaunchAllowedAfter";
  76
  77 // Prefix used to match the window class for Chrome windows.
  78 const wchar_t kChromeWindowClassPrefix[] = L"Chrome_WidgetWin_";
  79
  80 // Return the company name specified in the file version info resource.
  81 bool GetCompanyName(const wchar_t* filename, wchar_t* buffer, DWORD out_len) {
  82   wchar_t file_version_info[8192];
  83   DWORD handle = 0;
  84   DWORD buffer_size = 0;
  85
  86   buffer_size = ::GetFileVersionInfoSize(filename, &handle);
  87   // Cannot stats the file or our buffer size is too small (very unlikely).
  88   if (buffer_size == 0 || buffer_size > _countof(file_version_info))
  89     return false;
  90
  91   buffer_size = _countof(file_version_info);
  92   memset(file_version_info, 0, buffer_size);
  93   if (!::GetFileVersionInfo(filename, handle, buffer_size, file_version_info))
  94     return false;
  95
  96   DWORD data_len = 0;
  97   LPVOID data = NULL;
  98   // Retrieve the language and codepage code if exists.
  99   buffer_size = 0;
 100   if (!::VerQueryValue(file_version_info, TEXT("\\VarFileInfo\\Translation"),
 101       reinterpret_cast<LPVOID *>(&data), reinterpret_cast<UINT *>(&data_len)))
 102     return false;
 103   if (data_len != 4)
 104     return false;
 105
 106   wchar_t info_name[256];
 107   DWORD lang = 0;
 108   // Formulate the string to retrieve the company name of the specific
 109   // language codepage.
 110   memcpy(&lang, data, 4);
 111   ::StringCchPrintf(info_name, _countof(info_name),
 112       L"\\StringFileInfo\\%02X%02X%02X%02X\\CompanyName",
 113       (lang & 0xff00)>>8, (lang & 0xff), (lang & 0xff000000)>>24,
 114       (lang & 0xff0000)>>16);
 115
 116   data_len = 0;
 117   if (!::VerQueryValue(file_version_info, info_name,
 118       reinterpret_cast<LPVOID *>(&data), reinterpret_cast<UINT *>(&data_len)))
 119     return false;
 120   if (data_len <= 0 || data_len >= (out_len / sizeof(wchar_t)))
 121     return false;
 122
 123   memset(buffer, 0, out_len);
 124   ::StringCchCopyN(buffer,
 125                    (out_len / sizeof(wchar_t)),
 126                    reinterpret_cast<const wchar_t*>(data),
 127                    data_len);
 128   return true;
 129 }
 130
 131 // Offsets the current date by |months|. |months| must be between 0 and 12.
 132 // The returned date is in the YYYYMMDD format.
 133 DWORD FormatDateOffsetByMonths(int months) {
 134   DCHECK(months >= 0 && months <= 12);
 135
 136   SYSTEMTIME now;
 137   GetLocalTime(&now);
 138   now.wMonth += months;
 139   if (now.wMonth > 12) {
 140     now.wMonth -= 12;
 141     now.wYear += 1;
 142   }
 143
 144   return now.wYear * 10000 + now.wMonth * 100 + now.wDay;
 145 }
 146
 147 // Return true if we can re-offer Chrome; false, otherwise.
 148 // Each partner can only offer Chrome once every six months.
 149 bool CanReOfferChrome(BOOL set_flag) {
 150   wchar_t filename[MAX_PATH+1];
 151   wchar_t company[MAX_PATH];
 152
 153   // If we cannot retrieve the version info of the executable or company
 154   // name, we allow the Chrome to be offered because there is no past
 155   // history to be found.
 156   if (::GetModuleFileName(NULL, filename, MAX_PATH) == 0)
 157     return true;
 158   if (!GetCompanyName(filename, company, sizeof(company)))
 159     return true;
 160
 161   bool can_re_offer = true;
 162   DWORD disposition = 0;
 163   HKEY key = NULL;
 164   if (::RegCreateKeyEx(HKEY_LOCAL_MACHINE, kNoChromeOfferUntil,
 165       0, NULL, REG_OPTION_NON_VOLATILE, KEY_READ | KEY_WRITE,
 166       NULL, &key, &disposition) == ERROR_SUCCESS) {
 167     // Get today's date, and format it as YYYYMMDD numeric value.
 168     DWORD today = FormatDateOffsetByMonths(0);
 169
 170     // Cannot re-offer, if the timer already exists and is not expired yet.
 171     DWORD value_type = REG_DWORD;
 172     DWORD value_data = 0;
 173     DWORD value_length = sizeof(DWORD);
 174     if (::RegQueryValueEx(key, company, 0, &value_type,
 175                           reinterpret_cast<LPBYTE>(&value_data),
 176                           &value_length) == ERROR_SUCCESS &&
 177         REG_DWORD == value_type &&
 178         value_data > today) {
 179       // The time has not expired, we cannot offer Chrome.
 180       can_re_offer = false;
 181     } else {
 182       // Delete the old or invalid value.
 183       ::RegDeleteValue(key, company);
 184       if (set_flag) {
 185         // Set expiration date for offer as six months from today,
 186         // represented as a YYYYMMDD numeric value.
 187         DWORD value = FormatDateOffsetByMonths(6);
 188         ::RegSetValueEx(key, company, 0, REG_DWORD, (LPBYTE)&value,
 189                         sizeof(DWORD));
 190       }
 191     }
 192
 193     ::RegCloseKey(key);
 194   }
 195
 196   return can_re_offer;
 197 }
 198
 199 bool IsChromeInstalled(HKEY root_key) {
 200   RegKey key;
 201   return key.Open(root_key,
 202                   kChromeRegClientsKey,
 203                   KEY_READ | KEY_WOW64_32KEY) == ERROR_SUCCESS &&
 204          key.HasValue(kChromeRegVersion);
 205 }
 206
 207 // Returns true if the |subkey| in |root| has the kC1FKey entry set to 1.
 208 bool RegKeyHasC1F(HKEY root, const wchar_t* subkey) {
 209   RegKey key;
 210   DWORD value;
 211   return key.Open(root, subkey, KEY_READ | KEY_WOW64_32KEY) == ERROR_SUCCESS &&
 212       key.ReadValueDW(kC1FKey, &value) == ERROR_SUCCESS &&
 213       value == static_cast<DWORD>(1);
 214 }
 215
 216 bool IsC1FSent() {
 217   // The C1F RLZ key can either be in HKCU or in HKLM (the HKLM RLZ key is made
 218   // readable to all-users via rlz_lib::CreateMachineState()) and can either be
 219   // in sent or pending state. Return true if there is a match for any of these
 220   // 4 states.
 221   return RegKeyHasC1F(HKEY_CURRENT_USER, kC1FSentKey) ||
 222       RegKeyHasC1F(HKEY_CURRENT_USER, kC1FPendingKey) ||
 223       RegKeyHasC1F(HKEY_LOCAL_MACHINE, kC1FSentKey) ||
 224       RegKeyHasC1F(HKEY_LOCAL_MACHINE, kC1FPendingKey);
 225 }
 226
 227 enum WindowsVersion {
 228   VERSION_BELOW_XP_SP2,
 229   VERSION_XP_SP2_UP_TO_VISTA,  // "but not including"
 230   VERSION_VISTA_OR_HIGHER,
 231 };
 232 WindowsVersion GetWindowsVersion() {
 233   OSVERSIONINFOEX version_info = { sizeof version_info };
 234   GetVersionEx(reinterpret_cast<OSVERSIONINFO*>(&version_info));
 235
 236   // Windows Vista is version 6.0.
 237   if (version_info.dwMajorVersion >= 6)
 238     return VERSION_VISTA_OR_HIGHER;
 239
 240   // Windows XP is version 5.1.  (5.2 is Windows Server 2003/XP Pro x64.)
 241   if ((version_info.dwMajorVersion < 5) || (version_info.dwMinorVersion < 1))
 242     return VERSION_BELOW_XP_SP2;
 243
 244   // For XP itself, we only support SP2 and above.
 245   return ((version_info.dwMinorVersion > 1) ||
 246           (version_info.wServicePackMajor >= 2)) ?
 247       VERSION_XP_SP2_UP_TO_VISTA : VERSION_BELOW_XP_SP2;
 248 }
 249
 250 // Note this function should not be called on old Windows versions where these
 251 // Windows API are not available. We always invoke this function after checking
 252 // that current OS is Vista or later.
 253 bool VerifyAdminGroup() {
 254   SID_IDENTIFIER_AUTHORITY NtAuthority = {SECURITY_NT_AUTHORITY};
 255   PSID Group;
 256   BOOL check = ::AllocateAndInitializeSid(&NtAuthority, 2,
 257                                           SECURITY_BUILTIN_DOMAIN_RID,
 258                                           DOMAIN_ALIAS_RID_ADMINS, 0, 0, 0,
 259                                           0, 0, 0,
 260                                           &Group);
 261   if (check) {
 262     if (!::CheckTokenMembership(NULL, Group, &check))
 263       check = FALSE;
 264   }
 265   ::FreeSid(Group);
 266   return (check == TRUE);
 267 }
 268
 269 bool VerifyHKLMAccess() {
 270   wchar_t str[] = L"test";
 271   bool result = false;
 272   DWORD disposition = 0;
 273   HKEY key = NULL;
 274
 275   if (::RegCreateKeyEx(HKEY_LOCAL_MACHINE, kGCAPITempKey, 0, NULL,
 276                        REG_OPTION_NON_VOLATILE,
 277                        KEY_READ | KEY_WRITE | KEY_WOW64_32KEY, NULL,
 278                        &key, &disposition) == ERROR_SUCCESS) {
 279     if (::RegSetValueEx(key, str, 0, REG_SZ, (LPBYTE)str,
 280         (DWORD)lstrlen(str)) == ERROR_SUCCESS) {
 281       result = true;
 282       RegDeleteValue(key, str);
 283     }
 284
 285     RegCloseKey(key);
 286
 287     //  If we create the main key, delete the entire key.
 288     if (disposition == REG_CREATED_NEW_KEY)
 289       RegDeleteKey(HKEY_LOCAL_MACHINE, kGCAPITempKey);
 290   }
 291
 292   return result;
 293 }
 294
 295 bool IsRunningElevated() {
 296   // This method should be called only for Vista or later.
 297   if ((GetWindowsVersion() < VERSION_VISTA_OR_HIGHER) ||
 298       !VerifyAdminGroup())
 299     return false;
 300
 301   HANDLE process_token;
 302   if (!::OpenProcessToken(GetCurrentProcess(), TOKEN_QUERY, &process_token))
 303     return false;
 304
 305   TOKEN_ELEVATION_TYPE elevation_type = TokenElevationTypeDefault;
 306   DWORD size_returned = 0;
 307   if (!::GetTokenInformation(process_token, TokenElevationType,
 308                              &elevation_type, sizeof(elevation_type),
 309                              &size_returned)) {
 310     ::CloseHandle(process_token);
 311     return false;
 312   }
 313
 314   ::CloseHandle(process_token);
 315   return (elevation_type == TokenElevationTypeFull);
 316 }
 317
 318 bool GetUserIdForProcess(size_t pid, wchar_t** user_sid) {
 319   HANDLE process_handle = ::OpenProcess(PROCESS_QUERY_INFORMATION, TRUE, pid);
 320   if (process_handle == NULL)
 321     return false;
 322
 323   HANDLE process_token;
 324   bool result = false;
 325   if (::OpenProcessToken(process_handle, TOKEN_QUERY, &process_token)) {
 326     DWORD size = 0;
 327     ::GetTokenInformation(process_token, TokenUser, NULL, 0, &size);
 328     if (::GetLastError() == ERROR_INSUFFICIENT_BUFFER ||
 329         ::GetLastError() == ERROR_SUCCESS) {
 330       DWORD actual_size = 0;
 331       BYTE* token_user = new BYTE[size];
 332       if ((::GetTokenInformation(process_token, TokenUser, token_user, size,
 333                                 &actual_size)) &&
 334           (actual_size <= size)) {
 335         PSID sid = reinterpret_cast<TOKEN_USER*>(token_user)->User.Sid;
 336         if (::ConvertSidToStringSid(sid, user_sid))
 337           result = true;
 338       }
 339       delete[] token_user;
 340     }
 341     ::CloseHandle(process_token);
 342   }
 343   ::CloseHandle(process_handle);
 344   return result;
 345 }
 346
 347 struct SetWindowPosParams {
 348   int x;
 349   int y;
 350   int width;
 351   int height;
 352   DWORD flags;
 353   HWND window_insert_after;
 354   bool success;
 355   std::set<HWND> shunted_hwnds;
 356 };
 357
 358 BOOL CALLBACK ChromeWindowEnumProc(HWND hwnd, LPARAM lparam) {
 359   wchar_t window_class[MAX_PATH] = {};
 360   SetWindowPosParams* params = reinterpret_cast<SetWindowPosParams*>(lparam);
 361
 362   if (!params->shunted_hwnds.count(hwnd) &&
 363       ::GetClassName(hwnd, window_class, arraysize(window_class)) &&
 364       base::StartsWith(window_class, kChromeWindowClassPrefix,
 365                        base::CompareCase::INSENSITIVE_ASCII) &&
 366       ::SetWindowPos(hwnd, params->window_insert_after, params->x, params->y,
 367                      params->width, params->height, params->flags)) {
 368     params->shunted_hwnds.insert(hwnd);
 369     params->success = true;
 370   }
 371
 372   // Return TRUE to ensure we hit all possible top-level Chrome windows as per
 373   // http://msdn.microsoft.com/en-us/library/windows/desktop/ms633498.aspx
 374   return TRUE;
 375 }
 376
 377 // Returns true and populates |chrome_exe_path| with the path to chrome.exe if
 378 // a valid installation can be found.
 379 bool GetGoogleChromePath(base::FilePath* chrome_exe_path) {
 380   HKEY install_key = HKEY_LOCAL_MACHINE;
 381   if (!IsChromeInstalled(install_key)) {
 382     install_key = HKEY_CURRENT_USER;
 383     if (!IsChromeInstalled(install_key)) {
 384       return false;
 385     }
 386   }
 387
 388   // Now grab the uninstall string from the appropriate ClientState key
 389   // and use that as the base for a path to chrome.exe.
 390   *chrome_exe_path = chrome_launcher_support::GetChromePathForInstallationLevel(
 391       install_key == HKEY_LOCAL_MACHINE
 392           ? chrome_launcher_support::SYSTEM_LEVEL_INSTALLATION
 393           : chrome_launcher_support::USER_LEVEL_INSTALLATION,
 394       false /* is_sxs */);
 395   return !chrome_exe_path->empty();
 396 }
 397
 398 }  // namespace
 399
 400 BOOL __stdcall GoogleChromeCompatibilityCheck(BOOL set_flag,
 401                                               int shell_mode,
 402                                               DWORD* reasons) {
 403   DWORD local_reasons = 0;
 404
 405   WindowsVersion windows_version = GetWindowsVersion();
 406   // System requirements?
 407   if (windows_version == VERSION_BELOW_XP_SP2)
 408     local_reasons |= GCCC_ERROR_OSNOTSUPPORTED;
 409
 410   if (IsChromeInstalled(HKEY_LOCAL_MACHINE))
 411     local_reasons |= GCCC_ERROR_SYSTEMLEVELALREADYPRESENT;
 412
 413   if (IsChromeInstalled(HKEY_CURRENT_USER))
 414     local_reasons |= GCCC_ERROR_USERLEVELALREADYPRESENT;
 415
 416   if (shell_mode == GCAPI_INVOKED_UAC_ELEVATION) {
 417     // Only check that we have HKLM write permissions if we specify that
 418     // GCAPI is being invoked from an elevated shell, or in admin mode
 419     if (!VerifyHKLMAccess()) {
 420     local_reasons |= GCCC_ERROR_ACCESSDENIED;
 421     } else if ((windows_version == VERSION_VISTA_OR_HIGHER) &&
 422          !VerifyAdminGroup()) {
 423     // For Vista or later check for elevation since even for admin user we could
 424     // be running in non-elevated mode. We require integrity level High.
 425     local_reasons |= GCCC_ERROR_INTEGRITYLEVEL;
 426     }
 427   }
 428
 429   // Then only check whether we can re-offer, if everything else is OK.
 430   if (local_reasons == 0 && !CanReOfferChrome(set_flag))
 431     local_reasons |= GCCC_ERROR_ALREADYOFFERED;
 432
 433   // Done. Copy/return results.
 434   if (reasons != NULL)
 435     *reasons = local_reasons;
 436
 437   return (local_reasons == 0);
 438 }
 439
 440 BOOL __stdcall LaunchGoogleChrome() {
 441   base::FilePath chrome_exe_path;
 442   if (!GetGoogleChromePath(&chrome_exe_path))
 443     return false;
 444
 445   ScopedCOMInitializer com_initializer;
 446   if (::CoInitializeSecurity(NULL, -1, NULL, NULL,
 447                              RPC_C_AUTHN_LEVEL_PKT_PRIVACY,
 448                              RPC_C_IMP_LEVEL_IDENTIFY, NULL,
 449                              EOAC_DYNAMIC_CLOAKING, NULL) != S_OK) {
 450     return false;
 451   }
 452
 453   bool impersonation_success = false;
 454   if (IsRunningElevated()) {
 455     wchar_t* curr_proc_sid;
 456     if (!GetUserIdForProcess(GetCurrentProcessId(), &curr_proc_sid)) {
 457       return false;
 458     }
 459
 460     DWORD pid = 0;
 461     ::GetWindowThreadProcessId(::GetShellWindow(), &pid);
 462     if (pid <= 0) {
 463       ::LocalFree(curr_proc_sid);
 464       return false;
 465     }
 466
 467     wchar_t* exp_proc_sid;
 468     if (GetUserIdForProcess(pid, &exp_proc_sid)) {
 469       if (_wcsicmp(curr_proc_sid, exp_proc_sid) == 0) {
 470         ScopedHandle process_handle(
 471             ::OpenProcess(PROCESS_DUP_HANDLE | PROCESS_QUERY_INFORMATION,
 472                           TRUE,
 473                           pid));
 474         if (process_handle.IsValid()) {
 475           HANDLE process_token = NULL;
 476           HANDLE user_token = NULL;
 477           if (::OpenProcessToken(process_handle.Get(),
 478                                  TOKEN_DUPLICATE | TOKEN_QUERY,
 479                                  &process_token) &&
 480               ::DuplicateTokenEx(process_token,
 481                                  TOKEN_IMPERSONATE | TOKEN_QUERY |
 482                                      TOKEN_ASSIGN_PRIMARY | TOKEN_DUPLICATE,
 483                                  NULL, SecurityImpersonation,
 484                                  TokenPrimary, &user_token) &&
 485               (::ImpersonateLoggedOnUser(user_token) != 0)) {
 486             impersonation_success = true;
 487           }
 488           if (user_token)
 489             ::CloseHandle(user_token);
 490           if (process_token)
 491             ::CloseHandle(process_token);
 492         }
 493       }
 494       ::LocalFree(exp_proc_sid);
 495     }
 496
 497     ::LocalFree(curr_proc_sid);
 498     if (!impersonation_success) {
 499       return false;
 500     }
 501   }
 502
 503   base::CommandLine chrome_command(chrome_exe_path);
 504
 505   bool ret = false;
 506   ScopedComPtr<IProcessLauncher> ipl;
 507   if (SUCCEEDED(ipl.CreateInstance(__uuidof(ProcessLauncherClass),
 508                                    NULL,
 509                                    CLSCTX_LOCAL_SERVER))) {
 510     if (SUCCEEDED(ipl->LaunchCmdLine(
 511             chrome_command.GetCommandLineString().c_str())))
 512       ret = true;
 513     ipl.Release();
 514   } else {
 515     // Couldn't get Omaha's process launcher, Omaha may not be installed at
 516     // system level. Try just running Chrome instead.
 517     ret = base::LaunchProcess(chrome_command.GetCommandLineString(),
 518                               base::LaunchOptions()).IsValid();
 519   }
 520
 521   if (impersonation_success)
 522     ::RevertToSelf();
 523   return ret;
 524 }
 525
 526 BOOL __stdcall LaunchGoogleChromeWithDimensions(int x,
 527                                                 int y,
 528                                                 int width,
 529                                                 int height,
 530                                                 bool in_background) {
 531   if (in_background) {
 532     base::FilePath chrome_exe_path;
 533     if (!GetGoogleChromePath(&chrome_exe_path))
 534       return false;
 535
 536     // When launching in the background, use WMI to ensure that chrome.exe is
 537     // is not our child process. This prevents it from pushing itself to
 538     // foreground.
 539     base::CommandLine chrome_command(chrome_exe_path);
 540
 541     ScopedCOMInitializer com_initializer;
 542     if (!installer::WMIProcess::Launch(chrome_command.GetCommandLineString(),
 543                                        NULL)) {
 544       // For some reason WMI failed. Try and launch the old fashioned way,
 545       // knowing that visual glitches will occur when the window pops up.
 546       if (!LaunchGoogleChrome())
 547         return false;
 548     }
 549
 550   } else {
 551     if (!LaunchGoogleChrome())
 552       return false;
 553   }
 554
 555   HWND hwnd_insert_after = in_background ? HWND_BOTTOM : NULL;
 556   DWORD set_window_flags = in_background ? SWP_NOACTIVATE : SWP_NOZORDER;
 557
 558   if (x == -1 && y == -1)
 559     set_window_flags |= SWP_NOMOVE;
 560
 561   if (width == -1 && height == -1)
 562     set_window_flags |= SWP_NOSIZE;
 563
 564   SetWindowPosParams enum_params = { x, y, width, height, set_window_flags,
 565                                      hwnd_insert_after, false };
 566
 567   // Chrome may have been launched, but the window may not have appeared
 568   // yet. Wait for it to appear for 10 seconds, but exit if it takes longer
 569   // than that.
 570   int ms_elapsed = 0;
 571   int timeout = 10000;
 572   bool found_window = false;
 573   while (ms_elapsed < timeout) {
 574     // Enum all top-level windows looking for Chrome windows.
 575     ::EnumWindows(ChromeWindowEnumProc, reinterpret_cast<LPARAM>(&enum_params));
 576
 577     // Give it five more seconds after finding the first window until we stop
 578     // shoving new windows into the background.
 579     if (!found_window && enum_params.success) {
 580       found_window = true;
 581       timeout = ms_elapsed + 5000;
 582     }
 583
 584     Sleep(10);
 585     ms_elapsed += 10;
 586   }
 587
 588   return found_window;
 589 }
 590
 591 BOOL __stdcall LaunchGoogleChromeInBackground() {
 592   return LaunchGoogleChromeWithDimensions(-1, -1, -1, -1, true);
 593 }
 594
 595 int __stdcall GoogleChromeDaysSinceLastRun() {
 596   int days_since_last_run = std::numeric_limits<int>::max();
 597
 598   if (IsChromeInstalled(HKEY_LOCAL_MACHINE) ||
 599       IsChromeInstalled(HKEY_CURRENT_USER)) {
 600     RegKey client_state(HKEY_CURRENT_USER,
 601                         kChromeRegClientStateKey,
 602                         KEY_QUERY_VALUE | KEY_WOW64_32KEY);
 603     if (client_state.Valid()) {
 604       base::string16 last_run;
 605       int64 last_run_value = 0;
 606       if (client_state.ReadValue(google_update::kRegLastRunTimeField,
 607                                  &last_run) == ERROR_SUCCESS &&
 608           base::StringToInt64(last_run, &last_run_value)) {
 609         Time last_run_time = Time::FromInternalValue(last_run_value);
 610         TimeDelta difference = Time::NowFromSystemTime() - last_run_time;
 611
 612         // We can end up with negative numbers here, given changes in system
 613         // clock time or due to TimeDelta's int64 -> int truncation.
 614         int new_days_since_last_run = difference.InDays();
 615         if (new_days_since_last_run >= 0 &&
 616             new_days_since_last_run < days_since_last_run) {
 617           days_since_last_run = new_days_since_last_run;
 618         }
 619       }
 620     }
 621   }
 622
 623   if (days_since_last_run == std::numeric_limits<int>::max()) {
 624     days_since_last_run = -1;
 625   }
 626
 627   return days_since_last_run;
 628 }
 629
 630 BOOL __stdcall CanOfferReactivation(const wchar_t* brand_code,
 631                                     int shell_mode,
 632                                     DWORD* error_code) {
 633   DCHECK(error_code);
 634
 635   if (!brand_code) {
 636     if (error_code)
 637       *error_code = REACTIVATE_ERROR_INVALID_INPUT;
 638     return FALSE;
 639   }
 640
 641   int days_since_last_run = GoogleChromeDaysSinceLastRun();
 642   if (days_since_last_run >= 0 &&
 643       days_since_last_run < kReactivationMinDaysDormant) {
 644     if (error_code)
 645       *error_code = REACTIVATE_ERROR_NOTDORMANT;
 646     return FALSE;
 647   }
 648
 649   // Only run the code below when this function is invoked from a standard,
 650   // non-elevated cmd shell.  This is because this section of code looks at
 651   // values in HKEY_CURRENT_USER, and we only want to look at the logged-in
 652   // user's HKCU, not the admin user's HKCU.
 653   if (shell_mode == GCAPI_INVOKED_STANDARD_SHELL) {
 654     if (!IsChromeInstalled(HKEY_LOCAL_MACHINE) &&
 655         !IsChromeInstalled(HKEY_CURRENT_USER)) {
 656       if (error_code)
 657         *error_code = REACTIVATE_ERROR_NOTINSTALLED;
 658       return FALSE;
 659     }
 660
 661     if (HasBeenReactivated()) {
 662       if (error_code)
 663         *error_code = REACTIVATE_ERROR_ALREADY_REACTIVATED;
 664       return FALSE;
 665     }
 666   }
 667
 668   return TRUE;
 669 }
 670
 671 BOOL __stdcall ReactivateChrome(const wchar_t* brand_code,
 672                                 int shell_mode,
 673                                 DWORD* error_code) {
 674   BOOL result = FALSE;
 675   if (CanOfferReactivation(brand_code,
 676                            shell_mode,
 677                            error_code)) {
 678     if (SetReactivationBrandCode(brand_code, shell_mode)) {
 679       // Currently set this as a best-effort thing. We return TRUE if
 680       // reactivation succeeded regardless of the experiment label result.
 681       SetReactivationExperimentLabels(brand_code, shell_mode);
 682
 683       result = TRUE;
 684     } else {
 685       if (error_code)
 686         *error_code = REACTIVATE_ERROR_REACTIVATION_FAILED;
 687     }
 688   }
 689
 690   return result;
 691 }
 692
 693 BOOL __stdcall CanOfferRelaunch(const wchar_t** partner_brandcode_list,
 694                                 int partner_brandcode_list_length,
 695                                 int shell_mode,
 696                                 DWORD* error_code) {
 697   DCHECK(error_code);
 698
 699   if (!partner_brandcode_list || partner_brandcode_list_length <= 0) {
 700     if (error_code)
 701       *error_code = RELAUNCH_ERROR_INVALID_INPUT;
 702     return FALSE;
 703   }
 704
 705   // These conditions need to be satisfied for relaunch:
 706   // a) Chrome should be installed;
 707   if (!IsChromeInstalled(HKEY_LOCAL_MACHINE) &&
 708       (shell_mode != GCAPI_INVOKED_STANDARD_SHELL ||
 709           !IsChromeInstalled(HKEY_CURRENT_USER))) {
 710     if (error_code)
 711       *error_code = RELAUNCH_ERROR_NOTINSTALLED;
 712     return FALSE;
 713   }
 714
 715   // b) the installed brandcode should belong to that partner (in
 716   // brandcode_list);
 717   base::string16 installed_brandcode;
 718   bool valid_brandcode = false;
 719   if (GoogleUpdateSettings::GetBrand(&installed_brandcode)) {
 720     for (int i = 0; i < partner_brandcode_list_length; ++i) {
 721       if (!_wcsicmp(installed_brandcode.c_str(), partner_brandcode_list[i])) {
 722         valid_brandcode = true;
 723         break;
 724       }
 725     }
 726   }
 727
 728   if (!valid_brandcode) {
 729     if (error_code)
 730       *error_code = RELAUNCH_ERROR_INVALID_PARTNER;
 731     return FALSE;
 732   }
 733
 734   // c) C1F ping should not have been sent;
 735   if (IsC1FSent()) {
 736     if (error_code)
 737       *error_code = RELAUNCH_ERROR_PINGS_SENT;
 738     return FALSE;
 739   }
 740
 741   // d) a minimum period (30 days) must have passed since Chrome was last used;
 742   int days_since_last_run = GoogleChromeDaysSinceLastRun();
 743   if (days_since_last_run >= 0 &&
 744       days_since_last_run < kRelaunchMinDaysDormant) {
 745     if (error_code)
 746       *error_code = RELAUNCH_ERROR_NOTDORMANT;
 747     return FALSE;
 748   }
 749
 750   // e) a minimum period (6 months) must have passed since the previous
 751   // relaunch offer for the current user;
 752   RegKey key;
 753   DWORD min_relaunch_date;
 754   if (key.Open(HKEY_CURRENT_USER,
 755                kChromeRegClientStateKey,
 756                KEY_QUERY_VALUE | KEY_WOW64_32KEY) == ERROR_SUCCESS &&
 757       key.ReadValueDW(kRelaunchAllowedAfterValue,
 758                       &min_relaunch_date) == ERROR_SUCCESS &&
 759       FormatDateOffsetByMonths(0) < min_relaunch_date) {
 760     if (error_code)
 761       *error_code = RELAUNCH_ERROR_ALREADY_RELAUNCHED;
 762     return FALSE;
 763   }
 764
 765   return TRUE;
 766 }
 767
 768 BOOL __stdcall SetRelaunchOffered(const wchar_t** partner_brandcode_list,
 769                                   int partner_brandcode_list_length,
 770                                   const wchar_t* relaunch_brandcode,
 771                                   int shell_mode,
 772                                   DWORD* error_code) {
 773   if (!CanOfferRelaunch(partner_brandcode_list, partner_brandcode_list_length,
 774                         shell_mode, error_code))
 775     return FALSE;
 776
 777   // Store the relaunched brand code and the minimum date for relaunch (6 months
 778   // from now), and set the Omaha experiment label.
 779   RegKey key;
 780   if (key.Create(HKEY_CURRENT_USER,
 781                  kChromeRegClientStateKey,
 782                  KEY_SET_VALUE | KEY_WOW64_32KEY) != ERROR_SUCCESS ||
 783       key.WriteValue(kRelaunchBrandcodeValue,
 784                      relaunch_brandcode) != ERROR_SUCCESS ||
 785       key.WriteValue(kRelaunchAllowedAfterValue,
 786                      FormatDateOffsetByMonths(6)) != ERROR_SUCCESS ||
 787       !SetRelaunchExperimentLabels(relaunch_brandcode, shell_mode)) {
 788     if (error_code)
 789       *error_code = RELAUNCH_ERROR_RELAUNCH_FAILED;
 790     return FALSE;
 791   }
 792
 793   return TRUE;
 794 }