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// Copyright 2014 The PDFium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
// Original code copyright 2014 Foxit Software Inc. http://www.foxitsoftware.com
#include "fxjs/cfx_globaldata.h"
#include <utility>
#include "core/fdrm/fx_crypt.h"
#include "core/fxcrt/stl_util.h"
#include "third_party/base/numerics/safe_conversions.h"
namespace {
constexpr size_t kMinGlobalDataBytes = 12;
constexpr size_t kMaxGlobalDataBytes = 4 * 1024 - 8;
constexpr uint16_t kMagic = ('X' << 8) | 'F';
constexpr uint16_t kMaxVersion = 2;
const uint8_t kRC4KEY[] = {
0x19, 0xa8, 0xe8, 0x01, 0xf6, 0xa8, 0xb6, 0x4d, 0x82, 0x04, 0x45, 0x6d,
0xb4, 0xcf, 0xd7, 0x77, 0x67, 0xf9, 0x75, 0x9f, 0xf0, 0xe0, 0x1e, 0x51,
0xee, 0x46, 0xfd, 0x0b, 0xc9, 0x93, 0x25, 0x55, 0x4a, 0xee, 0xe0, 0x16,
0xd0, 0xdf, 0x8c, 0xfa, 0x2a, 0xa9, 0x49, 0xfd, 0x97, 0x1c, 0x0e, 0x22,
0x13, 0x28, 0x7c, 0xaf, 0xc4, 0xfc, 0x9c, 0x12, 0x65, 0x8c, 0x4e, 0x5b,
0x04, 0x75, 0x89, 0xc9, 0xb1, 0xed, 0x50, 0xca, 0x96, 0x6f, 0x1a, 0x7a,
0xfe, 0x58, 0x5d, 0xec, 0x19, 0x4a, 0xf6, 0x35, 0x6a, 0x97, 0x14, 0x00,
0x0e, 0xd0, 0x6b, 0xbb, 0xd5, 0x75, 0x55, 0x8b, 0x6e, 0x6b, 0x19, 0xa0,
0xf8, 0x77, 0xd5, 0xa3};
CFX_GlobalData* g_pInstance = nullptr;
// Returns true if non-empty, setting sPropName
bool TrimPropName(ByteString* sPropName) {
sPropName->Trim();
return sPropName->GetLength() != 0;
}
void MakeNameTypeString(const ByteString& name,
CFX_Value::DataType eType,
BinaryBuffer* result) {
uint32_t dwNameLen = pdfium::base::checked_cast<uint32_t>(name.GetLength());
result->AppendUint32(dwNameLen);
result->AppendString(name);
result->AppendUint16(static_cast<uint16_t>(eType));
}
bool MakeByteString(const ByteString& name,
const CFX_KeyValue& pData,
BinaryBuffer* result) {
switch (pData.nType) {
case CFX_Value::DataType::kNumber: {
MakeNameTypeString(name, pData.nType, result);
result->AppendDouble(pData.dData);
return true;
}
case CFX_Value::DataType::kBoolean: {
MakeNameTypeString(name, pData.nType, result);
result->AppendUint16(static_cast<uint16_t>(pData.bData));
return true;
}
case CFX_Value::DataType::kString: {
MakeNameTypeString(name, pData.nType, result);
uint32_t dwDataLen =
pdfium::base::checked_cast<uint32_t>(pData.sData.GetLength());
result->AppendUint32(dwDataLen);
result->AppendString(pData.sData);
return true;
}
case CFX_Value::DataType::kNull: {
MakeNameTypeString(name, pData.nType, result);
return true;
}
// Arrays don't get persisted per JS spec page 484.
case CFX_Value::DataType::kObject:
default:
break;
}
return false;
}
} // namespace
// static
CFX_GlobalData* CFX_GlobalData::GetRetainedInstance(Delegate* pDelegate) {
if (!g_pInstance) {
g_pInstance = new CFX_GlobalData(pDelegate);
}
++g_pInstance->m_RefCount;
return g_pInstance;
}
bool CFX_GlobalData::Release() {
if (--m_RefCount)
return false;
delete g_pInstance;
g_pInstance = nullptr;
return true;
}
CFX_GlobalData::CFX_GlobalData(Delegate* pDelegate) : m_pDelegate(pDelegate) {
LoadGlobalPersistentVariables();
}
CFX_GlobalData::~CFX_GlobalData() {
SaveGlobalPersisitentVariables();
}
CFX_GlobalData::iterator CFX_GlobalData::FindGlobalVariable(
const ByteString& propname) {
for (auto it = m_arrayGlobalData.begin(); it != m_arrayGlobalData.end();
++it) {
if ((*it)->data.sKey == propname)
return it;
}
return m_arrayGlobalData.end();
}
CFX_GlobalData::Element* CFX_GlobalData::GetGlobalVariable(
const ByteString& propname) {
auto iter = FindGlobalVariable(propname);
return iter != m_arrayGlobalData.end() ? iter->get() : nullptr;
}
void CFX_GlobalData::SetGlobalVariableNumber(ByteString sPropName,
double dData) {
if (!TrimPropName(&sPropName))
return;
CFX_GlobalData::Element* pData = GetGlobalVariable(sPropName);
if (pData) {
pData->data.nType = CFX_Value::DataType::kNumber;
pData->data.dData = dData;
return;
}
auto pNewData = std::make_unique<CFX_GlobalData::Element>();
pNewData->data.sKey = std::move(sPropName);
pNewData->data.nType = CFX_Value::DataType::kNumber;
pNewData->data.dData = dData;
m_arrayGlobalData.push_back(std::move(pNewData));
}
void CFX_GlobalData::SetGlobalVariableBoolean(ByteString sPropName,
bool bData) {
if (!TrimPropName(&sPropName))
return;
CFX_GlobalData::Element* pData = GetGlobalVariable(sPropName);
if (pData) {
pData->data.nType = CFX_Value::DataType::kBoolean;
pData->data.bData = bData;
return;
}
auto pNewData = std::make_unique<CFX_GlobalData::Element>();
pNewData->data.sKey = std::move(sPropName);
pNewData->data.nType = CFX_Value::DataType::kBoolean;
pNewData->data.bData = bData;
m_arrayGlobalData.push_back(std::move(pNewData));
}
void CFX_GlobalData::SetGlobalVariableString(ByteString sPropName,
const ByteString& sData) {
if (!TrimPropName(&sPropName))
return;
CFX_GlobalData::Element* pData = GetGlobalVariable(sPropName);
if (pData) {
pData->data.nType = CFX_Value::DataType::kString;
pData->data.sData = sData;
return;
}
auto pNewData = std::make_unique<CFX_GlobalData::Element>();
pNewData->data.sKey = std::move(sPropName);
pNewData->data.nType = CFX_Value::DataType::kString;
pNewData->data.sData = sData;
m_arrayGlobalData.push_back(std::move(pNewData));
}
void CFX_GlobalData::SetGlobalVariableObject(
ByteString sPropName,
std::vector<std::unique_ptr<CFX_KeyValue>> array) {
if (!TrimPropName(&sPropName))
return;
CFX_GlobalData::Element* pData = GetGlobalVariable(sPropName);
if (pData) {
pData->data.nType = CFX_Value::DataType::kObject;
pData->data.objData = std::move(array);
return;
}
auto pNewData = std::make_unique<CFX_GlobalData::Element>();
pNewData->data.sKey = std::move(sPropName);
pNewData->data.nType = CFX_Value::DataType::kObject;
pNewData->data.objData = std::move(array);
m_arrayGlobalData.push_back(std::move(pNewData));
}
void CFX_GlobalData::SetGlobalVariableNull(ByteString sPropName) {
if (!TrimPropName(&sPropName))
return;
CFX_GlobalData::Element* pData = GetGlobalVariable(sPropName);
if (pData) {
pData->data.nType = CFX_Value::DataType::kNull;
return;
}
auto pNewData = std::make_unique<CFX_GlobalData::Element>();
pNewData->data.sKey = std::move(sPropName);
pNewData->data.nType = CFX_Value::DataType::kNull;
m_arrayGlobalData.push_back(std::move(pNewData));
}
bool CFX_GlobalData::SetGlobalVariablePersistent(ByteString sPropName,
bool bPersistent) {
if (!TrimPropName(&sPropName))
return false;
CFX_GlobalData::Element* pData = GetGlobalVariable(sPropName);
if (!pData)
return false;
pData->bPersistent = bPersistent;
return true;
}
bool CFX_GlobalData::DeleteGlobalVariable(ByteString sPropName) {
if (!TrimPropName(&sPropName))
return false;
auto iter = FindGlobalVariable(sPropName);
if (iter == m_arrayGlobalData.end())
return false;
m_arrayGlobalData.erase(iter);
return true;
}
int32_t CFX_GlobalData::GetSize() const {
return fxcrt::CollectionSize<int32_t>(m_arrayGlobalData);
}
CFX_GlobalData::Element* CFX_GlobalData::GetAt(int index) {
if (index < 0 || index >= GetSize())
return nullptr;
return m_arrayGlobalData[index].get();
}
bool CFX_GlobalData::LoadGlobalPersistentVariables() {
if (!m_pDelegate)
return false;
bool ret;
{
// Span can't outlive call to BufferDone().
absl::optional<pdfium::span<uint8_t>> buffer = m_pDelegate->LoadBuffer();
if (!buffer.has_value() || buffer.value().empty())
return false;
ret = LoadGlobalPersistentVariablesFromBuffer(buffer.value());
}
m_pDelegate->BufferDone();
return ret;
}
bool CFX_GlobalData::LoadGlobalPersistentVariablesFromBuffer(
pdfium::span<uint8_t> buffer) {
if (buffer.size() < kMinGlobalDataBytes)
return false;
CRYPT_ArcFourCryptBlock(buffer, kRC4KEY);
uint8_t* p = buffer.data();
uint16_t wType = *((uint16_t*)p);
p += sizeof(uint16_t);
if (wType != kMagic)
return false;
uint16_t wVersion = *((uint16_t*)p);
p += sizeof(uint16_t);
if (wVersion > kMaxVersion)
return false;
uint32_t dwCount = *((uint32_t*)p);
p += sizeof(uint32_t);
uint32_t dwSize = *((uint32_t*)p);
p += sizeof(uint32_t);
if (dwSize != buffer.size() - sizeof(uint16_t) * 2 - sizeof(uint32_t) * 2)
return false;
for (int32_t i = 0, sz = dwCount; i < sz; i++) {
if (p > buffer.end())
break;
uint32_t dwNameLen = *((uint32_t*)p);
p += sizeof(uint32_t);
if (p + dwNameLen > buffer.end())
break;
ByteString sEntry = ByteString(p, dwNameLen);
p += sizeof(char) * dwNameLen;
CFX_Value::DataType wDataType =
static_cast<CFX_Value::DataType>(*((uint16_t*)p));
p += sizeof(uint16_t);
switch (wDataType) {
case CFX_Value::DataType::kNumber: {
double dData = 0;
switch (wVersion) {
case 1: {
uint32_t dwData = *((uint32_t*)p);
p += sizeof(uint32_t);
dData = dwData;
} break;
case 2: {
dData = *((double*)p);
p += sizeof(double);
} break;
}
SetGlobalVariableNumber(sEntry, dData);
SetGlobalVariablePersistent(sEntry, true);
} break;
case CFX_Value::DataType::kBoolean: {
uint16_t wData = *((uint16_t*)p);
p += sizeof(uint16_t);
SetGlobalVariableBoolean(sEntry, (bool)(wData == 1));
SetGlobalVariablePersistent(sEntry, true);
} break;
case CFX_Value::DataType::kString: {
uint32_t dwLength = *((uint32_t*)p);
p += sizeof(uint32_t);
if (p + dwLength > buffer.end())
break;
SetGlobalVariableString(sEntry, ByteString(p, dwLength));
SetGlobalVariablePersistent(sEntry, true);
p += sizeof(char) * dwLength;
} break;
case CFX_Value::DataType::kNull: {
SetGlobalVariableNull(sEntry);
SetGlobalVariablePersistent(sEntry, true);
} break;
case CFX_Value::DataType::kObject:
default:
// Arrays aren't allowed in these buffers, nor are unrecoginzed tags.
return false;
}
}
return true;
}
bool CFX_GlobalData::SaveGlobalPersisitentVariables() {
if (!m_pDelegate)
return false;
uint32_t nCount = 0;
BinaryBuffer sData;
for (const auto& pElement : m_arrayGlobalData) {
if (!pElement->bPersistent)
continue;
BinaryBuffer sElement;
if (!MakeByteString(pElement->data.sKey, pElement->data, &sElement))
continue;
if (sData.GetSize() + sElement.GetSize() > kMaxGlobalDataBytes)
break;
sData.AppendSpan(sElement.GetSpan());
nCount++;
}
BinaryBuffer sFile;
sFile.AppendUint16(kMagic);
sFile.AppendUint16(kMaxVersion);
sFile.AppendUint32(nCount);
uint32_t dwSize = pdfium::base::checked_cast<uint32_t>(sData.GetSize());
sFile.AppendUint32(dwSize);
sFile.AppendSpan(sData.GetSpan());
CRYPT_ArcFourCryptBlock(sFile.GetMutableSpan(), kRC4KEY);
return m_pDelegate->StoreBuffer(sFile.GetSpan());
}
CFX_GlobalData::Element::Element() = default;
CFX_GlobalData::Element::~Element() = default;