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// Copyright (c) 2009 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_frame/chrome_launcher.h"
#include <windows.h>
#include <shellapi.h>
#include <shlwapi.h>
// Herein lies stuff selectively stolen from Chrome. We don't pull it in
// directly because all of it results in many things we don't want being
// included as well.
namespace {
// These are the switches we will allow (along with their values) in the
// safe-for-Low-Integrity version of the Chrome command line.
// Including the chrome switch files pulls in a bunch of dependencies sadly, so
// we redefine things here:
const wchar_t* kAllowedSwitches[] = {
L"automation-channel",
L"chrome-frame",
L"disable-renderer-accessibility",
L"enable-experimental-extension-apis",
L"force-renderer-accessibility",
L"lang",
L"no-default-browser-check",
L"noerrdialogs",
L"no-first-run",
L"user-data-dir",
L"disable-popup-blocking",
L"full-memory-crash-report",
};
const wchar_t kWhitespaceChars[] = {
0x0009, /* <control-0009> to <control-000D> */
0x000A,
0x000B,
0x000C,
0x000D,
0x0020, /* Space */
0x0085, /* <control-0085> */
0x00A0, /* No-Break Space */
0x1680, /* Ogham Space Mark */
0x180E, /* Mongolian Vowel Separator */
0x2000, /* En Quad to Hair Space */
0x2001,
0x2002,
0x2003,
0x2004,
0x2005,
0x2006,
0x2007,
0x2008,
0x2009,
0x200A,
0x200C, /* Zero Width Non-Joiner */
0x2028, /* Line Separator */
0x2029, /* Paragraph Separator */
0x202F, /* Narrow No-Break Space */
0x205F, /* Medium Mathematical Space */
0x3000, /* Ideographic Space */
0
};
const wchar_t kLauncherExeBaseName[] = L"chrome_launcher.exe";
const wchar_t kBrowserProcessExecutableName[] = L"chrome.exe";
} // end namespace
namespace chrome_launcher {
std::wstring TrimWhiteSpace(const wchar_t* input_str) {
std::wstring output;
if (input_str != NULL) {
std::wstring str(input_str);
const std::wstring::size_type first_good_char =
str.find_first_not_of(kWhitespaceChars);
const std::wstring::size_type last_good_char =
str.find_last_not_of(kWhitespaceChars);
if (first_good_char != std::wstring::npos &&
last_good_char != std::wstring::npos &&
last_good_char >= first_good_char) {
// + 1 because find_last_not_of returns the index, and we want the count
output = str.substr(first_good_char,
last_good_char - first_good_char + 1);
}
}
return output;
}
bool IsValidArgument(const std::wstring& arg) {
if (arg.length() < 2) {
return false;
}
for (int i = 0; i < arraysize(kAllowedSwitches); ++i) {
size_t arg_length = lstrlenW(kAllowedSwitches[i]);
if (arg.find(kAllowedSwitches[i], 2) == 2) {
// The argument starts off right, now it must either end here, or be
// followed by an equals sign.
if (arg.length() == (arg_length + 2) ||
(arg.length() > (arg_length + 2) && arg[arg_length+2] == L'=')) {
return true;
}
}
}
return false;
}
bool IsValidCommandLine(const wchar_t* command_line) {
if (command_line == NULL) {
return false;
}
int num_args = 0;
wchar_t** args = NULL;
args = CommandLineToArgvW(command_line, &num_args);
bool success = true;
// Note that we skip args[0] since that is just our executable name and
// doesn't get passed through to Chrome.
for (int i = 1; i < num_args; ++i) {
std::wstring trimmed_arg = TrimWhiteSpace(args[i]);
if (!IsValidArgument(trimmed_arg.c_str())) {
success = false;
break;
}
}
return success;
}
bool SanitizeAndLaunchChrome(const wchar_t* command_line) {
bool success = false;
if (IsValidCommandLine(command_line)) {
std::wstring chrome_path;
if (GetChromeExecutablePath(&chrome_path)) {
const wchar_t* args = PathGetArgs(command_line);
if (args != NULL) {
chrome_path += L" ";
chrome_path += args;
}
STARTUPINFO startup_info = {0};
startup_info.cb = sizeof(startup_info);
startup_info.dwFlags = STARTF_USESHOWWINDOW;
startup_info.wShowWindow = SW_SHOW;
PROCESS_INFORMATION process_info = {0};
if (CreateProcess(NULL, &chrome_path[0],
NULL, NULL, FALSE, 0, NULL, NULL,
&startup_info, &process_info)) {
// Close handles.
CloseHandle(process_info.hThread);
CloseHandle(process_info.hProcess);
success = true;
} else {
_ASSERT(FALSE);
}
}
}
return success;
}
bool GetChromeExecutablePath(std::wstring* chrome_path) {
_ASSERT(chrome_path);
wchar_t cur_path[MAX_PATH * 4] = {0};
// Assume that we are always built into an exe.
GetModuleFileName(NULL, cur_path, arraysize(cur_path) / 2);
PathRemoveFileSpec(cur_path);
bool success = false;
if (PathAppend(cur_path, kBrowserProcessExecutableName)) {
if (!PathFileExists(cur_path)) {
// The installation model for Chrome places the DLLs in a versioned
// sub-folder one down from the Chrome executable. If we fail to find
// chrome.exe in the current path, try looking one up and launching that
// instead. In practice, that means we back up two and append the
// executable name again.
PathRemoveFileSpec(cur_path);
PathRemoveFileSpec(cur_path);
PathAppend(cur_path, kBrowserProcessExecutableName);
}
if (PathFileExists(cur_path)) {
*chrome_path = cur_path;
success = true;
}
}
return success;
}
} // namespace chrome_launcher
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