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// Copyright (c) 2013 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 "sandbox/win/src/named_pipe_dispatcher.h"
#include <stdint.h>
#include "base/strings/string_split.h"
#include "base/strings/string_util.h"
#include "sandbox/win/src/crosscall_client.h"
#include "sandbox/win/src/interception.h"
#include "sandbox/win/src/interceptors.h"
#include "sandbox/win/src/ipc_tags.h"
#include "sandbox/win/src/named_pipe_interception.h"
#include "sandbox/win/src/named_pipe_policy.h"
#include "sandbox/win/src/policy_broker.h"
#include "sandbox/win/src/policy_params.h"
#include "sandbox/win/src/sandbox.h"
namespace sandbox {
NamedPipeDispatcher::NamedPipeDispatcher(PolicyBase* policy_base)
: policy_base_(policy_base) {
static const IPCCall create_params = {
{IpcTag::CREATENAMEDPIPEW,
{WCHAR_TYPE, UINT32_TYPE, UINT32_TYPE, UINT32_TYPE, UINT32_TYPE,
UINT32_TYPE, UINT32_TYPE}},
reinterpret_cast<CallbackGeneric>(&NamedPipeDispatcher::CreateNamedPipe)};
ipc_calls_.push_back(create_params);
}
bool NamedPipeDispatcher::SetupService(InterceptionManager* manager,
IpcTag service) {
if (IpcTag::CREATENAMEDPIPEW == service)
return INTERCEPT_EAT(manager, kKerneldllName, CreateNamedPipeW,
CREATE_NAMED_PIPE_ID, 36);
return false;
}
bool NamedPipeDispatcher::CreateNamedPipe(IPCInfo* ipc,
std::wstring* name,
uint32_t open_mode,
uint32_t pipe_mode,
uint32_t max_instances,
uint32_t out_buffer_size,
uint32_t in_buffer_size,
uint32_t default_timeout) {
ipc->return_info.win32_result = ERROR_ACCESS_DENIED;
ipc->return_info.handle = INVALID_HANDLE_VALUE;
base::StringPiece16 dotdot(STRING16_LITERAL(".."));
for (const base::StringPiece16& path : base::SplitStringPiece(
base::AsStringPiece16(*name), STRING16_LITERAL("/"),
base::TRIM_WHITESPACE, base::SPLIT_WANT_ALL)) {
for (const base::StringPiece16& inner :
base::SplitStringPiece(path, STRING16_LITERAL("\\"),
base::TRIM_WHITESPACE, base::SPLIT_WANT_ALL)) {
if (inner == dotdot)
return true;
}
}
const wchar_t* pipe_name = name->c_str();
CountedParameterSet<NameBased> params;
params[NameBased::NAME] = ParamPickerMake(pipe_name);
EvalResult eval =
policy_base_->EvalPolicy(IpcTag::CREATENAMEDPIPEW, params.GetBase());
// "For file I/O, the "\\?\" prefix to a path string tells the Windows APIs to
// disable all string parsing and to send the string that follows it straight
// to the file system."
// http://msdn.microsoft.com/en-us/library/aa365247(VS.85).aspx
// This ensures even if there is a path traversal in the pipe name, and it is
// able to get past the checks above, it will still not be allowed to escape
// our allowed namespace.
if (name->compare(0, 4, L"\\\\.\\") == 0)
name->replace(0, 4, L"\\\\\?\\");
HANDLE pipe;
DWORD ret = NamedPipePolicy::CreateNamedPipeAction(
eval, *ipc->client_info, *name, open_mode, pipe_mode, max_instances,
out_buffer_size, in_buffer_size, default_timeout, &pipe);
ipc->return_info.win32_result = ret;
ipc->return_info.handle = pipe;
return true;
}
} // namespace sandbox
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