blob: 49d4693fbd3d661313d22e883285e8ace955af7e [file] [log] [blame]
// Copyright 2021 The Chromium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#include "base/win/security_util.h"
#include <windows.h>
#include <winternl.h>
#include "base/check.h"
#include "base/files/file_path.h"
#include "base/logging.h"
#include "base/win/access_control_list.h"
#include "base/win/scoped_handle.h"
#include "base/win/security_descriptor.h"
#include "third_party/abseil-cpp/absl/types/optional.h"
namespace base {
namespace win {
namespace {
bool AddACEToPath(const FilePath& path,
const std::vector<Sid>& sids,
DWORD access_mask,
DWORD inheritance,
bool recursive,
SecurityAccessMode access_mode) {
DCHECK(!path.empty());
if (sids.empty()) {
return true;
}
absl::optional<SecurityDescriptor> sd =
SecurityDescriptor::FromFile(path, DACL_SECURITY_INFORMATION);
if (!sd) {
return false;
}
std::vector<ExplicitAccessEntry> entries;
for (const Sid& sid : sids) {
entries.emplace_back(sid, access_mode, access_mask, inheritance);
}
if (!sd->SetDaclEntries(entries)) {
return false;
}
if (recursive) {
return sd->WriteToFile(path, DACL_SECURITY_INFORMATION);
}
ScopedHandle handle(::CreateFile(path.value().c_str(), WRITE_DAC, 0, nullptr,
OPEN_EXISTING, FILE_FLAG_BACKUP_SEMANTICS,
nullptr));
if (!handle.is_valid()) {
DPLOG(ERROR) << "Failed opening path \"" << path.value()
<< "\" to write DACL";
return false;
}
return sd->WriteToHandle(handle.get(), SecurityObjectType::kKernel,
DACL_SECURITY_INFORMATION);
}
} // namespace
bool GrantAccessToPath(const FilePath& path,
const std::vector<Sid>& sids,
DWORD access_mask,
DWORD inheritance,
bool recursive) {
return AddACEToPath(path, sids, access_mask, inheritance, recursive,
SecurityAccessMode::kGrant);
}
bool DenyAccessToPath(const FilePath& path,
const std::vector<Sid>& sids,
DWORD access_mask,
DWORD inheritance,
bool recursive) {
return AddACEToPath(path, sids, access_mask, inheritance, recursive,
SecurityAccessMode::kDeny);
}
std::vector<Sid> CloneSidVector(const std::vector<Sid>& sids) {
std::vector<Sid> clone;
clone.reserve(sids.size());
for (const Sid& sid : sids) {
clone.push_back(sid.Clone());
}
return clone;
}
void AppendSidVector(std::vector<Sid>& base_sids,
const std::vector<Sid>& append_sids) {
for (const Sid& sid : append_sids) {
base_sids.push_back(sid.Clone());
}
}
absl::optional<ACCESS_MASK> GetGrantedAccess(HANDLE handle) {
PUBLIC_OBJECT_BASIC_INFORMATION basic_info = {};
if (!NT_SUCCESS(::NtQueryObject(handle, ObjectBasicInformation, &basic_info,
sizeof(basic_info), nullptr))) {
return absl::nullopt;
}
return basic_info.GrantedAccess;
}
} // namespace win
} // namespace base