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-rw-r--r--browser/app/winlauncher/LaunchUnelevated.cpp290
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diff --git a/browser/app/winlauncher/LaunchUnelevated.cpp b/browser/app/winlauncher/LaunchUnelevated.cpp
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index 0000000000..3cf6ac837c
--- /dev/null
+++ b/browser/app/winlauncher/LaunchUnelevated.cpp
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+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=2 et sw=2 tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at https://mozilla.org/MPL/2.0/. */
+
+#include "LaunchUnelevated.h"
+
+#include "mozilla/Assertions.h"
+#include "mozilla/CmdLineAndEnvUtils.h"
+#include "mozilla/mscom/ProcessRuntime.h"
+#include "mozilla/RefPtr.h"
+#include "mozilla/ShellHeaderOnlyUtils.h"
+#include "mozilla/WinHeaderOnlyUtils.h"
+#include "../BrowserDefines.h"
+#include "nsWindowsHelpers.h"
+
+#include <windows.h>
+
+#if !defined(RRF_SUBKEY_WOW6464KEY)
+# define RRF_SUBKEY_WOW6464KEY 0x00010000
+#endif // !defined(RRF_SUBKEY_WOW6464KEY)
+
+static mozilla::LauncherResult<bool> IsHighIntegrity(
+ const nsAutoHandle& aToken) {
+ DWORD reqdLen;
+ if (!::GetTokenInformation(aToken.get(), TokenIntegrityLevel, nullptr, 0,
+ &reqdLen)) {
+ DWORD err = ::GetLastError();
+ if (err != ERROR_INSUFFICIENT_BUFFER) {
+ return LAUNCHER_ERROR_FROM_WIN32(err);
+ }
+ }
+
+ auto buf = mozilla::MakeUnique<char[]>(reqdLen);
+
+ if (!::GetTokenInformation(aToken.get(), TokenIntegrityLevel, buf.get(),
+ reqdLen, &reqdLen)) {
+ return LAUNCHER_ERROR_FROM_LAST();
+ }
+
+ auto tokenLabel = reinterpret_cast<PTOKEN_MANDATORY_LABEL>(buf.get());
+
+ DWORD subAuthCount = *::GetSidSubAuthorityCount(tokenLabel->Label.Sid);
+ DWORD integrityLevel =
+ *::GetSidSubAuthority(tokenLabel->Label.Sid, subAuthCount - 1);
+ return integrityLevel > SECURITY_MANDATORY_MEDIUM_RID;
+}
+
+static mozilla::LauncherResult<HANDLE> GetMediumIntegrityToken(
+ const nsAutoHandle& aProcessToken) {
+ HANDLE rawResult;
+ if (!::DuplicateTokenEx(aProcessToken.get(), 0, nullptr,
+ SecurityImpersonation, TokenPrimary, &rawResult)) {
+ return LAUNCHER_ERROR_FROM_LAST();
+ }
+
+ nsAutoHandle result(rawResult);
+
+ BYTE mediumIlSid[SECURITY_MAX_SID_SIZE];
+ DWORD mediumIlSidSize = sizeof(mediumIlSid);
+ if (!::CreateWellKnownSid(WinMediumLabelSid, nullptr, mediumIlSid,
+ &mediumIlSidSize)) {
+ return LAUNCHER_ERROR_FROM_LAST();
+ }
+
+ TOKEN_MANDATORY_LABEL integrityLevel = {};
+ integrityLevel.Label.Attributes = SE_GROUP_INTEGRITY;
+ integrityLevel.Label.Sid = reinterpret_cast<PSID>(mediumIlSid);
+
+ if (!::SetTokenInformation(rawResult, TokenIntegrityLevel, &integrityLevel,
+ sizeof(integrityLevel))) {
+ return LAUNCHER_ERROR_FROM_LAST();
+ }
+
+ return result.disown();
+}
+
+static mozilla::LauncherResult<bool> IsAdminByAppCompat(
+ HKEY aRootKey, const wchar_t* aExecutablePath) {
+ static const wchar_t kPathToLayers[] =
+ L"SOFTWARE\\Microsoft\\Windows NT\\CurrentVersion\\"
+ L"AppCompatFlags\\Layers";
+
+ DWORD dataLength = 0;
+ LSTATUS status = ::RegGetValueW(aRootKey, kPathToLayers, aExecutablePath,
+ RRF_RT_REG_SZ | RRF_SUBKEY_WOW6464KEY,
+ nullptr, nullptr, &dataLength);
+ if (status == ERROR_FILE_NOT_FOUND) {
+ return false;
+ } else if (status != ERROR_SUCCESS) {
+ return LAUNCHER_ERROR_FROM_WIN32(status);
+ }
+
+ auto valueData = mozilla::MakeUnique<wchar_t[]>(dataLength);
+ if (!valueData) {
+ return LAUNCHER_ERROR_FROM_WIN32(ERROR_OUTOFMEMORY);
+ }
+
+ status = ::RegGetValueW(aRootKey, kPathToLayers, aExecutablePath,
+ RRF_RT_REG_SZ | RRF_SUBKEY_WOW6464KEY, nullptr,
+ valueData.get(), &dataLength);
+ if (status != ERROR_SUCCESS) {
+ return LAUNCHER_ERROR_FROM_WIN32(status);
+ }
+
+ const wchar_t kRunAsAdmin[] = L"RUNASADMIN";
+ const wchar_t kDelimiters[] = L" ";
+ wchar_t* tokenContext = nullptr;
+ const wchar_t* token = wcstok_s(valueData.get(), kDelimiters, &tokenContext);
+ while (token) {
+ if (!_wcsnicmp(token, kRunAsAdmin, mozilla::ArrayLength(kRunAsAdmin))) {
+ return true;
+ }
+ token = wcstok_s(nullptr, kDelimiters, &tokenContext);
+ }
+
+ return false;
+}
+
+namespace mozilla {
+
+// If we're running at an elevated integrity level, re-run ourselves at the
+// user's normal integrity level. We do this by locating the active explorer
+// shell, and then asking it to do a ShellExecute on our behalf. We do it this
+// way to ensure that the child process runs as the original user in the active
+// session; an elevated process could be running with different credentials than
+// those of the session.
+// See https://devblogs.microsoft.com/oldnewthing/20131118-00/?p=2643
+
+LauncherVoidResult LaunchUnelevated(int aArgc, wchar_t* aArgv[]) {
+ // We need COM to talk to Explorer. Using ProcessRuntime so that
+ // process-global COM configuration is done correctly
+ mozilla::mscom::ProcessRuntime mscom(
+ mozilla::mscom::ProcessRuntime::ProcessCategory::Launcher);
+ if (!mscom) {
+ return LAUNCHER_ERROR_FROM_HRESULT(mscom.GetHResult());
+ }
+
+ // Omit the original argv[0] because ShellExecute doesn't need it. Insert
+ // ATTEMPTING_DEELEVATION_FLAG so that we know not to attempt to restart
+ // ourselves if deelevation fails.
+ UniquePtr<wchar_t[]> cmdLine = [&]() {
+ constexpr wchar_t const* kTagArg = L"--" ATTEMPTING_DEELEVATION_FLAG;
+
+ // This should have already been checked, but just in case...
+ EnsureBrowserCommandlineSafe(aArgc, aArgv);
+
+ if (mozilla::CheckArg(aArgc, aArgv, "osint", nullptr, CheckArgFlag::None)) {
+ // If the command line contains -osint, we have to arrange things in a
+ // particular order.
+ //
+ // (We can't just replace -osint with kTagArg, unfortunately: there is
+ // code in the browser which behaves differently in the presence of an
+ // `-osint` tag, but which will not have had a chance to react to this.
+ // See, _e.g._, bug 1243603.)
+ auto const aArgvCopy = MakeUnique<wchar_t const*[]>(aArgc + 1);
+ aArgvCopy[0] = aArgv[1];
+ aArgvCopy[1] = kTagArg;
+ for (int i = 2; i < aArgc; ++i) {
+ aArgvCopy[i] = aArgv[i];
+ }
+ aArgvCopy[aArgc] = nullptr; // because argv[argc] is NULL
+ return MakeCommandLine(aArgc, aArgvCopy.get(), 0, nullptr);
+ } else {
+ // Otherwise, just tack it on at the end.
+ constexpr wchar_t const* const kTagArgArray[] = {kTagArg};
+ return MakeCommandLine(aArgc - 1, aArgv + 1, 1, kTagArgArray);
+ }
+ }();
+ if (!cmdLine) {
+ return LAUNCHER_ERROR_GENERIC();
+ }
+
+ _bstr_t cmd;
+
+ UniquePtr<wchar_t[]> packageFamilyName = mozilla::GetPackageFamilyName();
+ if (packageFamilyName) {
+ int cmdLen =
+ // 22 for the prefix + suffix + null terminator below
+ 22 + wcslen(packageFamilyName.get());
+ wchar_t appCmd[cmdLen];
+ swprintf(appCmd, cmdLen, L"shell:appsFolder\\%s!App",
+ packageFamilyName.get());
+ cmd = appCmd;
+ } else {
+ cmd = aArgv[0];
+ }
+
+ _variant_t args(cmdLine.get());
+ _variant_t operation(L"open");
+ _variant_t directory;
+ _variant_t showCmd(SW_SHOWNORMAL);
+ return ShellExecuteByExplorer(cmd, args, operation, directory, showCmd);
+}
+
+LauncherResult<ElevationState> GetElevationState(
+ const wchar_t* aExecutablePath, mozilla::LauncherFlags aFlags,
+ nsAutoHandle& aOutMediumIlToken) {
+ aOutMediumIlToken.reset();
+
+ const DWORD tokenFlags = TOKEN_QUERY | TOKEN_DUPLICATE |
+ TOKEN_ADJUST_DEFAULT | TOKEN_ASSIGN_PRIMARY;
+ HANDLE rawToken;
+ if (!::OpenProcessToken(::GetCurrentProcess(), tokenFlags, &rawToken)) {
+ return LAUNCHER_ERROR_FROM_LAST();
+ }
+
+ nsAutoHandle token(rawToken);
+
+ LauncherResult<TOKEN_ELEVATION_TYPE> elevationType = GetElevationType(token);
+ if (elevationType.isErr()) {
+ return elevationType.propagateErr();
+ }
+
+ Maybe<ElevationState> elevationState;
+ switch (elevationType.unwrap()) {
+ case TokenElevationTypeLimited:
+ return ElevationState::eNormalUser;
+ case TokenElevationTypeFull:
+ elevationState = Some(ElevationState::eElevated);
+ break;
+ case TokenElevationTypeDefault: {
+ // In this case, UAC is disabled. We do not yet know whether or not we
+ // are running at high integrity. If we are at high integrity, we can't
+ // relaunch ourselves in a non-elevated state via Explorer, as we would
+ // just end up in an infinite loop of launcher processes re-launching
+ // themselves.
+ LauncherResult<bool> isHighIntegrity = IsHighIntegrity(token);
+ if (isHighIntegrity.isErr()) {
+ return isHighIntegrity.propagateErr();
+ }
+
+ if (!isHighIntegrity.unwrap()) {
+ return ElevationState::eNormalUser;
+ }
+
+ elevationState = Some(ElevationState::eHighIntegrityNoUAC);
+ break;
+ }
+ default:
+ MOZ_ASSERT_UNREACHABLE("Was a new value added to the enumeration?");
+ return LAUNCHER_ERROR_GENERIC();
+ }
+
+ MOZ_ASSERT(elevationState.isSome() &&
+ elevationState.value() != ElevationState::eNormalUser,
+ "Should have returned earlier for the eNormalUser case.");
+
+ LauncherResult<bool> isAdminByAppCompat =
+ IsAdminByAppCompat(HKEY_CURRENT_USER, aExecutablePath);
+ if (isAdminByAppCompat.isErr()) {
+ return isAdminByAppCompat.propagateErr();
+ }
+
+ if (isAdminByAppCompat.unwrap()) {
+ elevationState = Some(ElevationState::eHighIntegrityByAppCompat);
+ } else {
+ isAdminByAppCompat =
+ IsAdminByAppCompat(HKEY_LOCAL_MACHINE, aExecutablePath);
+ if (isAdminByAppCompat.isErr()) {
+ return isAdminByAppCompat.propagateErr();
+ }
+
+ if (isAdminByAppCompat.unwrap()) {
+ elevationState = Some(ElevationState::eHighIntegrityByAppCompat);
+ }
+ }
+
+ // A medium IL token is not needed in the following cases.
+ // 1) We keep the process elevated (= LauncherFlags::eNoDeelevate)
+ // 2) The process was elevated by UAC (= ElevationState::eElevated)
+ // AND the launcher process doesn't wait for the browser process
+ if ((aFlags & mozilla::LauncherFlags::eNoDeelevate) ||
+ (elevationState.value() == ElevationState::eElevated &&
+ !(aFlags & mozilla::LauncherFlags::eWaitForBrowser))) {
+ return elevationState.value();
+ }
+
+ LauncherResult<HANDLE> tokenResult = GetMediumIntegrityToken(token);
+ if (tokenResult.isOk()) {
+ aOutMediumIlToken.own(tokenResult.unwrap());
+ } else {
+ return tokenResult.propagateErr();
+ }
+
+ return elevationState.value();
+}
+
+} // namespace mozilla