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// Copyright 2011 The Chromium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#ifdef UNSAFE_BUFFERS_BUILD
// TODO(crbug.com/40285824): Remove this and convert code to safer constructs.
#pragma allow_unsafe_buffers
#endif
#include "chrome/installer/util/set_reg_value_work_item.h"
#include "base/logging.h"
#include "base/strings/string_util.h"
#include "base/strings/utf_string_conversions.h"
#include "base/win/registry.h"
namespace {
// Transforms |str_value| into the byte-by-byte representation of its underlying
// string, stores the result in |binary_data|.
void StringToBinaryData(const std::wstring& str_value,
std::vector<uint8_t>* binary_data) {
DCHECK(binary_data);
const uint8_t* data = reinterpret_cast<const uint8_t*>(str_value.c_str());
binary_data->assign(data, data + (str_value.length() + 1) * sizeof(wchar_t));
}
// Transforms |binary_data| into its wstring representation (assuming
// |binary_data| is a sequence of wchar_t's).
void BinaryDataToString(const std::vector<uint8_t>& binary_data,
std::wstring* str_value) {
DCHECK(str_value);
if (binary_data.size() < sizeof(wchar_t)) {
str_value->clear();
return;
}
str_value->assign(reinterpret_cast<const wchar_t*>(&binary_data[0]),
binary_data.size() / sizeof(wchar_t));
// Trim off a trailing string terminator, if present.
if (!str_value->empty()) {
auto iter = str_value->end();
if (*--iter == L'\0')
str_value->erase(iter);
}
}
} // namespace
SetRegValueWorkItem::~SetRegValueWorkItem() = default;
SetRegValueWorkItem::SetRegValueWorkItem(HKEY predefined_root,
const std::wstring& key_path,
REGSAM wow64_access,
const std::wstring& value_name,
const std::wstring& value_data,
bool overwrite)
: predefined_root_(predefined_root),
key_path_(key_path),
value_name_(value_name),
overwrite_(overwrite),
wow64_access_(wow64_access),
type_(REG_SZ),
previous_type_(0),
status_(SET_VALUE) {
DCHECK(wow64_access == 0 || wow64_access == KEY_WOW64_32KEY ||
wow64_access == KEY_WOW64_64KEY);
StringToBinaryData(value_data, &value_);
}
SetRegValueWorkItem::SetRegValueWorkItem(HKEY predefined_root,
const std::wstring& key_path,
REGSAM wow64_access,
const std::wstring& value_name,
DWORD value_data,
bool overwrite)
: predefined_root_(predefined_root),
key_path_(key_path),
value_name_(value_name),
overwrite_(overwrite),
wow64_access_(wow64_access),
type_(REG_DWORD),
previous_type_(0),
status_(SET_VALUE) {
DCHECK(wow64_access == 0 || wow64_access == KEY_WOW64_32KEY ||
wow64_access == KEY_WOW64_64KEY);
const uint8_t* data = reinterpret_cast<const uint8_t*>(&value_data);
value_.assign(data, data + sizeof(value_data));
}
SetRegValueWorkItem::SetRegValueWorkItem(HKEY predefined_root,
const std::wstring& key_path,
REGSAM wow64_access,
const std::wstring& value_name,
int64_t value_data,
bool overwrite)
: predefined_root_(predefined_root),
key_path_(key_path),
value_name_(value_name),
overwrite_(overwrite),
wow64_access_(wow64_access),
type_(REG_QWORD),
previous_type_(0),
status_(SET_VALUE) {
DCHECK(wow64_access == 0 || wow64_access == KEY_WOW64_32KEY ||
wow64_access == KEY_WOW64_64KEY);
const uint8_t* data = reinterpret_cast<const uint8_t*>(&value_data);
value_.assign(data, data + sizeof(value_data));
}
SetRegValueWorkItem::SetRegValueWorkItem(
HKEY predefined_root,
const std::wstring& key_path,
REGSAM wow64_access,
const std::wstring& value_name,
GetValueFromExistingCallback get_value_callback)
: predefined_root_(predefined_root),
key_path_(key_path),
value_name_(value_name),
get_value_callback_(std::move(get_value_callback)),
overwrite_(true),
wow64_access_(wow64_access),
type_(REG_SZ),
previous_type_(0),
status_(SET_VALUE) {
DCHECK(wow64_access == 0 || wow64_access == KEY_WOW64_32KEY ||
wow64_access == KEY_WOW64_64KEY);
// Nothing to do, |get_value_callback| will fill |value_| later.
}
bool SetRegValueWorkItem::DoImpl() {
DCHECK_EQ(SET_VALUE, status_);
status_ = VALUE_UNCHANGED;
base::win::RegKey key;
LONG result = key.Open(predefined_root_, key_path_.c_str(),
KEY_READ | KEY_SET_VALUE | wow64_access_);
if (result != ERROR_SUCCESS) {
VLOG(1) << "can not open " << key_path_ << " error: " << result;
return false;
}
DWORD type = 0;
DWORD size = 0;
result = key.ReadValue(value_name_.c_str(), nullptr, &size, &type);
// If the value exists but we don't want to overwrite then there's
// nothing more to do.
if ((result != ERROR_FILE_NOT_FOUND) && !overwrite_) {
return true;
}
// If there's something to be saved, save it.
if (result == ERROR_SUCCESS && (rollback_enabled() || get_value_callback_)) {
if (!size) {
previous_type_ = type;
} else {
previous_value_.resize(size);
result = key.ReadValue(value_name_.c_str(), &previous_value_[0], &size,
&previous_type_);
if (result != ERROR_SUCCESS) {
previous_value_.clear();
VLOG(1) << "Failed to save original value. Error: " << result;
}
}
}
if (!get_value_callback_.is_null()) {
// Although this could be made more generic, for now this assumes the
// |type_| of |value_| is REG_SZ.
DCHECK_EQ(static_cast<DWORD>(REG_SZ), type_);
// Fill |previous_value_str| with the wstring representation of the binary
// data in |previous_value_| as long as it's of type REG_SZ (leave it empty
// otherwise).
std::wstring previous_value_str;
if (previous_type_ == REG_SZ)
BinaryDataToString(previous_value_, &previous_value_str);
StringToBinaryData(std::move(get_value_callback_).Run(previous_value_str),
&value_);
}
result = key.WriteValue(value_name_.c_str(), &value_[0],
static_cast<DWORD>(value_.size()), type_);
if (result != ERROR_SUCCESS) {
VLOG(1) << "Failed to write value " << key_path_ << " error: " << result;
return false;
}
if (VLOG_IS_ON(1)) {
if (type_ == REG_SZ) {
std::wstring value_str;
BinaryDataToString(value_, &value_str);
VLOG(1) << "Successfully wrote value " << value_str << " into "
<< key_path_;
} else {
VLOG(1) << "Successfully wrote into " << key_path_;
}
}
status_ = previous_type_ ? VALUE_OVERWRITTEN : NEW_VALUE_CREATED;
return true;
}
void SetRegValueWorkItem::RollbackImpl() {
DCHECK_NE(SET_VALUE, status_);
DCHECK_NE(VALUE_ROLL_BACK, status_);
if (status_ == VALUE_UNCHANGED) {
status_ = VALUE_ROLL_BACK;
VLOG(1) << "rollback: setting unchanged, nothing to do";
return;
}
base::win::RegKey key;
LONG result = key.Open(predefined_root_, key_path_.c_str(),
KEY_SET_VALUE | wow64_access_);
if (result != ERROR_SUCCESS) {
VLOG(1) << "rollback: can not open " << key_path_ << " error: " << result;
return;
}
if (status_ == NEW_VALUE_CREATED) {
result = key.DeleteValue(value_name_.c_str());
VLOG(1) << "rollback: deleting " << value_name_ << " error: " << result;
} else if (status_ == VALUE_OVERWRITTEN) {
const unsigned char* previous_value =
previous_value_.empty() ? nullptr : &previous_value_[0];
result = key.WriteValue(value_name_.c_str(), previous_value,
static_cast<DWORD>(previous_value_.size()),
previous_type_);
VLOG(1) << "rollback: restoring " << value_name_ << " error: " << result;
} else {
NOTREACHED();
}
status_ = VALUE_ROLL_BACK;
}
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