/*
 * Copyright (C) Ascensio System SIA, 2009-2026
 *
 * 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, together with the
 * additional terms provided in the LICENSE file.
 *
 * 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: https://www.gnu.org/licenses/agpl-3.0.html
 *
 * You can contact Ascensio System SIA by email at info@onlyoffice.com
 * or by postal mail at 20A-6 Ernesta Birznieka-Upisha Street, Riga,
 * LV-1050, Latvia, European Union.
 *
 * The interactive user interfaces in modified versions of the Program
 * are required to display Appropriate Legal Notices in accordance with
 * Section 5 of the GNU AGPL version 3.
 *
 * No trademark rights are granted under this License.
 *
 * All non-code elements of the Product, including illustrations,
 * icon sets, and technical writing content, are licensed under the
 * Creative Commons Attribution-ShareAlike 4.0 International License:
 * https://creativecommons.org/licenses/by-sa/4.0/legalcode
 *
 * This license applies only to such non-code elements and does not
 * modify or replace the licensing terms applicable to the Program's
 * source code, which remains licensed under the GNU Affero General
 * Public License v3.
 *
 * SPDX-License-Identifier: AGPL-3.0-only
 */
#ifndef _PDF_WRITER_SRC_ENCRYPT_H
#define _PDF_WRITER_SRC_ENCRYPT_H

#include "Utils.h"

#define ID_LEN              16
#define PERMISSION_PAD      0xFFFFFFC0

#define SET_BYTE_FUNC(Name, m_memory) \
void Name(const BYTE* pSrc, unsigned int unLen)\
{\
    memcpy(m_memory, pSrc, unLen);\
}
#define SET_UN_FUNC(Name, m_memory) \
void Name(unsigned int unVal)\
{\
    m_memory = unVal;\
}

namespace PdfWriter
{
	class CEncrypt
	{
	public:

        CEncrypt();
        virtual ~CEncrypt();

		void CreateUserKey();
		void CreateOwnerKey();
		void CreateEncryptionKey();
		void InitKey(unsigned int unObjectId, unsigned short unGenNo);
		void Reset();
        unsigned int CryptBuf(const BYTE* pSrc, BYTE* pDst, unsigned int unLen);
        void SetKeyLength(unsigned int unLen);
        void SetPasswords(const std::string &sUserPassword, const std::string &sOwnerPassword);
        bool MakeFileKey(int nCryptAlgorithm);

        SET_BYTE_FUNC(SetID, m_anEncryptID);
        SET_BYTE_FUNC(SetO,  m_anOwnerKey);
        SET_BYTE_FUNC(SetU,  m_anUserKey);
        SET_BYTE_FUNC(SetOE, m_anOwnerEncryptKey);
        SET_BYTE_FUNC(SetUE, m_anUserEncryptKey);
        SET_BYTE_FUNC(SetPerms, m_anPermEncrypt);

        SET_UN_FUNC(SetPermission, m_unPermission);
        SET_UN_FUNC(SetRevision, m_unRevision);
        SET_UN_FUNC(SetVersion, m_unVersion);
	private:
        class Impl;
        Impl *impl;

        bool MakeFileKey3(const std::string &sPassword, unsigned char *pHash, int nHashSize, unsigned char *pHash2 = NULL, int nHashSize2 = 0);
        bool MakeFileKey2(BYTE* sUserPassword, int nLength);
		
        unsigned int    m_unKeyLen;

        BYTE            m_anOwnerKey[48];           //O
        BYTE            m_anUserKey[48];            //U
        BYTE            m_anOwnerEncryptKey[32];    //OE
        BYTE            m_anUserEncryptKey[32];     //UE
        unsigned int    m_unPermission;             //P
        BYTE            m_anPermEncrypt[16];        //Perm
        unsigned int    m_unVersion;                //V
        unsigned int    m_unRevision;               //R

        BYTE            m_anEncryptID[ID_LEN];
        unsigned int    m_unIDLength;

		friend class CEncryptDict;
		friend class CDocument;
	};
}

#endif // _PDF_WRITER_SRC_ENCRYPT_H