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DocumentServer-v-9.2.0/core/PdfFile/SrcWriter/EncryptDictionary.cpp
Yajbir Singh f1b860b25c
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/*
* (c) Copyright Ascensio System SIA 2010-2023
*
* This program is a free software product. You can redistribute it and/or
* modify it under the terms of the GNU Affero General Public License (AGPL)
* version 3 as published by the Free Software Foundation. In accordance with
* Section 7(a) of the GNU AGPL its Section 15 shall be amended to the effect
* that Ascensio System SIA expressly excludes the warranty of non-infringement
* of any third-party rights.
*
* This program is distributed WITHOUT ANY WARRANTY; without even the implied
* warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. For
* details, see the GNU AGPL at: http://www.gnu.org/licenses/agpl-3.0.html
*
* You can contact Ascensio System SIA at 20A-6 Ernesta Birznieka-Upish
* street, Riga, Latvia, EU, LV-1050.
*
* The interactive user interfaces in modified source and object code versions
* of the Program must display Appropriate Legal Notices, as required under
* Section 5 of the GNU AGPL version 3.
*
* Pursuant to Section 7(b) of the License you must retain the original Product
* logo when distributing the program. Pursuant to Section 7(e) we decline to
* grant you any rights under trademark law for use of our trademarks.
*
* All the Product's GUI elements, including illustrations and icon sets, as
* well as technical writing content are licensed under the terms of the
* Creative Commons Attribution-ShareAlike 4.0 International. See the License
* terms at http://creativecommons.org/licenses/by-sa/4.0/legalcode
*
*/
#include "EncryptDictionary.h"
#include "Encrypt.h"
#include "Info.h"
#include "Streams.h"
#include <ctime>
#include "../../Common/3dParty/cryptopp/md5.h"
#include "../../UnicodeConverter/UnicodeConverter.h"
#define SET_BINARY_PARAM(Name, set_func) \
pObj = Get(Name);\
if (pObj && pObj->GetType() == object_type_BINARY)\
m_pEncrypt->set_func(((CBinaryObject*)pObj)->GetValue(), ((CBinaryObject*)pObj)->GetLength());
#define SET_NUMBER_PARAM(Name, set_func) \
pObj = Get(Name);\
if (pObj && pObj->GetType() == object_type_NUMBER)\
m_pEncrypt->set_func(((CNumberObject*)pObj)->Get());
namespace PdfWriter
{
//----------------------------------------------------------------------------------------
// CEncryptDict
//----------------------------------------------------------------------------------------
CEncryptDict::CEncryptDict()
{
m_pEncrypt = new CEncrypt();
}
CEncryptDict::CEncryptDict(CXref* pXref)
{
m_pEncrypt = new CEncrypt();
pXref->Add(this);
}
void CEncryptDict::Fix()
{
CObjectBase* pObj = NULL;
SET_BINARY_PARAM("O", SetO);
SET_BINARY_PARAM("U", SetU);
SET_BINARY_PARAM("OE", SetOE);
SET_BINARY_PARAM("UE", SetUE);
SET_BINARY_PARAM("Perms", SetPerms);
SET_BINARY_PARAM("ID", SetID);
pObj = Get("ID");
if (pObj && pObj->GetType() == object_type_BINARY)
m_pEncrypt->m_unIDLength = ((CBinaryObject*)pObj)->GetLength();
Remove("ID");
SET_NUMBER_PARAM("P", SetPermission);
SET_NUMBER_PARAM("R", SetRevision);
SET_NUMBER_PARAM("V", SetVersion);
SET_NUMBER_PARAM("Length", SetKeyLength);
}
CEncryptDict::~CEncryptDict()
{
if (m_pEncrypt)
delete m_pEncrypt;
}
void CEncryptDict::CreateId(CInfoDict* pInfo, CXref* pXref, BYTE* pBuffer)
{
CryptoPP::MD5 hash;
std::time_t oTime = time(0);
hash.Update( (BYTE*)&oTime, sizeof(oTime));
// Создаем идентификатор файла по элементам библиотеки Info.
if (pInfo)
{
const char *sTemp = NULL;
unsigned int nLen = 0;
// Author
sTemp = pInfo->GetInfo(InfoAuthor);
if ((nLen = StrLen(sTemp, -1)) > 0)
hash.Update( (const BYTE *)sTemp, nLen );
// Creator
sTemp = pInfo->GetInfo(InfoCreator);
if ((nLen = StrLen(sTemp, -1)) > 0)
hash.Update( (const BYTE *)sTemp, nLen);
// Producer
sTemp = pInfo->GetInfo(InfoProducer);
if ((nLen = StrLen(sTemp, -1)) > 0)
hash.Update( (const BYTE *)sTemp, nLen);
// Title
sTemp = pInfo->GetInfo(InfoTitle);
if ((nLen = StrLen(sTemp, -1)) > 0)
hash.Update( (const BYTE *)sTemp, nLen);
// Subject
sTemp = pInfo->GetInfo(InfoSubject);
if ((nLen = StrLen(sTemp, -1)) > 0)
hash.Update( (const BYTE *)sTemp, nLen);
// Keywords
sTemp = pInfo->GetInfo(InfoKeyWords);
if ((nLen = StrLen(sTemp, -1)) > 0)
hash.Update( (const BYTE *)sTemp, nLen);
int nXrefEntriesCount = pXref->GetCount();
hash.Update( (const BYTE *)&nXrefEntriesCount, sizeof(unsigned int));
}
CryptoPP::SecByteBlock buffer(hash.DigestSize());
hash.Final(buffer);
memcpy(pBuffer, buffer.BytePtr(), buffer.size());
}
std::string CEncryptDict::PadOrTrancatePassword(const std::wstring & wsPassword)
{
NSUnicodeConverter::CUnicodeConverter conv;
std::string sNewPassword = conv.SASLprepToUtf8(wsPassword);
if (sNewPassword.length() > 127)
sNewPassword = sNewPassword.substr(0, 127);
return sNewPassword;
}
void CEncryptDict::SetPasswords(const std::wstring & wsOwnerPassword, const std::wstring & wsUserPassword)
{
std::string sOwnerPassword = PadOrTrancatePassword(wsOwnerPassword);
std::string sUserPassword = PadOrTrancatePassword(wsUserPassword);
m_pEncrypt->SetPasswords(sUserPassword, sOwnerPassword);
}
void CEncryptDict::Prepare(CInfoDict* pInfo, CXref* pXref)
{
CreateId(pInfo, pXref, (BYTE*)m_pEncrypt->m_anEncryptID);
m_pEncrypt->CreateEncryptionKey();
m_pEncrypt->CreateUserKey();
m_pEncrypt->CreateOwnerKey();
Add("Filter", "Standard");
Add("V", 5);
Add("Length", m_pEncrypt->m_unKeyLen * 8);
Add("R", 6);
Add("P", m_pEncrypt->m_unPermission);
CDictObject* pCF = new CDictObject();
CDictObject* pStdCF = new CDictObject();
pCF->Add("StdCF", pStdCF);
pStdCF->Add("CFM", "AESV3");
pStdCF->Add("AuthEvent", "DocOpen");
pStdCF->Add("Length", m_pEncrypt->m_unKeyLen);
Add("CF", pCF);
Add("StmF", "StdCF");
Add("StrF", "StdCF");
CBinaryObject* pUserKey = new CBinaryObject(m_pEncrypt->m_anUserKey, 48);
if (!pUserKey)
return;
CBinaryObject* pUserEncryptKey = new CBinaryObject(m_pEncrypt->m_anUserEncryptKey, 32);
if (!pUserKey)
return;
Add("U", pUserKey);
Add("UE", pUserEncryptKey);
CBinaryObject* pOwnerKey = new CBinaryObject(m_pEncrypt->m_anOwnerKey, 48);
if (!pOwnerKey)
return;
CBinaryObject* pOwnerEncryptKey = new CBinaryObject(m_pEncrypt->m_anOwnerEncryptKey, 32);
if (!pOwnerKey)
return;
Add("O", pOwnerKey);
Add("OE", pOwnerEncryptKey);
CBinaryObject* pEncryptPerm = new CBinaryObject(m_pEncrypt->m_anPermEncrypt, 16);
Add("Perms", pEncryptPerm);
}
bool CEncryptDict::UpdateKey(int nCryptAlgorithm)
{
return m_pEncrypt->MakeFileKey(nCryptAlgorithm);
}
//----------------------------------------------------------------------------------------
// CSignatureDict
//----------------------------------------------------------------------------------------
CSignatureDict::CSignatureDict(CXref* pXref)
{
pXref->Add(this);
Add("Type", "Sig");
Add("Filter", "Adobe.PPKLite");
Add("SubFilter", "adbe.pkcs7.detached");
unsigned int unDigestLength = 15000;
BYTE* pDigest = new BYTE[unDigestLength];
memset(pDigest, 0, unDigestLength);
Add("Contents", new CBinaryObject(pDigest, unDigestLength));
RELEASEARRAYOBJECTS(pDigest);
CArrayObject* pByteRange = new CArrayObject();
if (!pByteRange)
return;
Add("ByteRange", pByteRange);
pByteRange->Add(0);
pByteRange->Add(1234567890);
pByteRange->Add(1234567890);
pByteRange->Add(1234567890);
// Reference - Массив справочных словарей сигнатур
// Changes - Массив из трех чисел, который указывает изменения в документе в порядке: количество измененных страниц,
// количество измененных полей и количество заполненных полей
// Порядок подписей определяется значением ByteRange. Поскольку каждая подпись приводит к добавочному сохранению,
// более поздние подписи имеют большее значение длины
// Prop_Build - Словарь, который может использоваться обработчиком подписи для записи информации о состоянии компьютерной среды,
// используемой для подписи, такой как имя обработчика, используемого для создания подписи, дата сборки программного обеспечения,
// версия, и операционная система. Спецификация словаря PDF Signature Build содержит рекомендации по использованию этого словаря
m_nLen1 = 0;
m_nOffset2 = 0;
m_nByteRangeBegin = 0;
m_nByteRangeEnd = 0;
}
CSignatureDict::~CSignatureDict()
{
}
void CSignatureDict::WriteToStream(CStream* pStream, CEncrypt* pEncrypt)
{
for (auto const &oIter : m_mList)
{
CObjectBase* pObject = oIter.second;
if (!pObject)
continue;
if (pObject->IsHidden())
{
// ничего не делаем
}
else
{
int nBegin, nEnd;
pStream->WriteEscapeName(oIter.first.c_str());
pStream->WriteChar(' ');
nBegin = pStream->Tell();
// Цифровая подпись не шифруется
pStream->Write(pObject, oIter.first == "Contents" ? NULL : pEncrypt);
nEnd = pStream->Tell();
pStream->WriteStr("\012");
if (oIter.first == "Contents")
{
m_nLen1 = nBegin;
m_nOffset2 = nEnd;
}
if (oIter.first == "ByteRange")
{
m_nByteRangeBegin = nBegin;
m_nByteRangeEnd = nEnd;
}
}
}
}
void CSignatureDict::WriteToStream(CStream* pStream, int nFileEnd)
{
// Запись ByteRange
if (m_nByteRangeBegin > 0 && m_nByteRangeEnd > 0 && m_nByteRangeBegin < m_nByteRangeEnd && m_nByteRangeEnd < nFileEnd)
{
CArrayObject* pByteRange = new CArrayObject();
if (!pByteRange)
return;
if (m_nLen1 > 0 && m_nOffset2 > 0 && m_nLen1 < m_nOffset2 && m_nOffset2 < nFileEnd)
{
pByteRange->Add(0);
pByteRange->Add(m_nLen1);
pByteRange->Add(m_nOffset2);
pByteRange->Add(nFileEnd - m_nOffset2);
pStream->Seek(m_nByteRangeBegin, EWhenceMode::SeekSet);
pStream->Write(pByteRange, NULL);
int nEnd = pStream->Tell();
if (nEnd < m_nByteRangeEnd)
{
unsigned int nLength = m_nByteRangeEnd - nEnd;
BYTE* pDifference = new BYTE[nLength];
MemSet(pDifference, ' ', nLength);
pStream->Write(pDifference, nLength);
RELEASEARRAYOBJECTS(pDifference);
}
}
RELEASEOBJECT(pByteRange);
}
// Запись Contents
if (m_pCertificate && m_nLen1 > 0 && m_nOffset2 > 0 && m_nLen1 < m_nOffset2 && m_nOffset2 < nFileEnd)
{
DWORD dwLenDataForSignature = m_nLen1 + nFileEnd - m_nOffset2;
BYTE* pDataForSignature = new BYTE[dwLenDataForSignature];
if (!pDataForSignature)
return;
pStream->Seek(0, EWhenceMode::SeekSet);
unsigned int dwLenReadData = m_nLen1;
pStream->Read(pDataForSignature, &dwLenReadData);
if ((int)dwLenReadData != m_nLen1)
{
RELEASEARRAYOBJECTS(pDataForSignature);
return;
}
pStream->Seek(m_nOffset2, EWhenceMode::SeekSet);
dwLenReadData = nFileEnd - m_nOffset2;
pStream->Read(pDataForSignature + m_nLen1, &dwLenReadData);
if ((int)dwLenReadData != nFileEnd - m_nOffset2)
{
RELEASEARRAYOBJECTS(pDataForSignature);
return;
}
BYTE* pDatatoWrite = NULL;
unsigned int dwLenDatatoWrite;
m_pCertificate->SignPKCS7(pDataForSignature, dwLenDataForSignature, pDatatoWrite, dwLenDatatoWrite);
RELEASEARRAYOBJECTS(pDataForSignature);
if (!pDatatoWrite)
return;
pStream->Seek(m_nLen1, EWhenceMode::SeekSet);
CBinaryObject* pContents = new CBinaryObject(pDatatoWrite, dwLenDatatoWrite);
RELEASEARRAYOBJECTS(pDatatoWrite);
if (!pContents)
return;
// Цифровая подпись не шифруется
pStream->Write(pContents, NULL);
RELEASEOBJECT(pContents);
// Стереть лишний >
BYTE cChar = '0';
pStream->Seek(pStream->Tell() - 1, EWhenceMode::SeekSet);
pStream->Write(&cChar, 1);
}
}
void CSignatureDict::SetCert(ICertificate* pCert)
{
m_pCertificate = pCert;
}
void CSignatureDict::SetName(const std::string& sName)
{
// Name - Cтрока, Имя лица или органа, подписавшего документ.
// Значение следует использовать когда невозможно извлечь имя из подписи или сертификата подписавшего.
Add("Name", new CStringObject(sName.c_str()));
}
void CSignatureDict::SetReason(const std::string& sReason)
{
// Reason - Строка, Причина подписания, например (Я согласен)
Add("Reason", new CStringObject(sReason.c_str()));
}
void CSignatureDict::SetContact(const std::string& sContacts)
{
// ContactInfo - Строка, Информация, предоставленная подписывающей стороной,
// чтобы получатель мог связаться с подписывающей стороной для проверки подписи, например (номерелефона)
Add("ContactInfo", new CStringObject(sContacts.c_str()));
}
void CSignatureDict::SetDate()
{
// M - Дата, Время подписания
// Значение следует использовать когда время подписания недоступно в подписи
Add("M", new CStringObject(DateNow().c_str()));
}
}