axmol/core/base/ZipUtils.h

/****************************************************************************
Copyright (c) 2010-2012 cocos2d-x.org
Copyright (c) 2013-2016 Chukong Technologies Inc.
Copyright (c) 2017-2018 Xiamen Yaji Software Co., Ltd.
Copyright (c) 2020 C4games Ltd

https://axmolengine.github.io/

Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to deal
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****************************************************************************/

#ifndef __SUPPORT_ZIPUTILS_H__
#define __SUPPORT_ZIPUTILS_H__
/// @cond DO_NOT_SHOW

#include "platform/PlatformMacros.h"
#include "platform/FileUtils.h"
#include <string>

#if (AX_TARGET_PLATFORM == AX_PLATFORM_ANDROID)
#    include "platform/android/FileUtils-android.h"
#elif (AX_TARGET_PLATFORM == AX_PLATFORM_WIN32)
// for import ssize_t on win32 platform
#    include "platform/StdC.h"
#endif

#ifndef _unz64_H
struct unz_file_info_s;
#endif

/**
 * @addtogroup base
 * @{
 */
NS_AX_BEGIN

/** XXX: pragma pack ???
 * @struct CCZHeader
 */
struct CCZHeader
{
    unsigned char sig[4];            /** Signature. Should be 'CCZ!' 4 bytes. */
    unsigned short compression_type; /** Should be 0. */
    unsigned short version;          /** Should be 2 (although version type==1 is also supported). */
    unsigned int reserved;           /** Reserved for users. */
    unsigned int len;                /** Size of the uncompressed file. */
};

enum
{
    CCZ_COMPRESSION_ZLIB,  /** zlib format. */
    CCZ_COMPRESSION_BZIP2, /** bzip2 format (not supported yet). */
    CCZ_COMPRESSION_GZIP,  /** gzip format (not supported yet). */
    CCZ_COMPRESSION_NONE,  /** plain (not supported yet). */
};

class AX_DLL ZipUtils
{
public:
    /**
     * Inflates either zlib or gzip deflated memory. The inflated memory is expected to be freed by the caller.
     *
     * It will allocate 256k for the destination buffer. If it is not enough it will multiply the previous buffer size
     * per 2, until there is enough memory.
     *
     * @return The length of the deflated buffer.
     * @since v0.8.1
     */
    static ssize_t inflateMemory(unsigned char* in, ssize_t inLength, unsigned char** out);

    /**
     * Inflates either zlib or gzip deflated memory. The inflated memory is expected to be freed by the caller.
     *
     * @param outLengthHint It is assumed to be the needed room to allocate the inflated buffer.
     *
     * @return The length of the deflated buffer.
     * @since v1.0.0
     */
    static ssize_t inflateMemoryWithHint(unsigned char* in,
                                         ssize_t inLength,
                                         unsigned char** out,
                                         ssize_t outLengthHint);

    /**
     * Inflates a GZip file into memory.
     *
     * @return The length of the deflated buffer.
     * @since v0.99.5
     */
    static int inflateGZipFile(const char* filename, unsigned char** out);

    /**
     * Test a file is a GZip format file or not.
     *
     * @return True is a GZip format file. false is not.
     * @since v3.0
     */
    static bool isGZipFile(const char* filename);

    /**
     * Test the buffer is GZip format or not.
     *
     * @return True is GZip format. false is not.
     * @since v3.0
     */
    static bool isGZipBuffer(const unsigned char* buffer, ssize_t len);

    /**
     * Inflates a CCZ file into memory.
     *
     * @return The length of the deflated buffer.
     * @since v0.99.5
     */
    static int inflateCCZFile(const char* filename, unsigned char** out);

    /**
     * Inflates a buffer with CCZ format into memory.
     *
     * @return The length of the deflated buffer.
     * @since v3.0
     */
    static int inflateCCZBuffer(const unsigned char* buffer, ssize_t len, unsigned char** out);

    /**
     * Test a file is a CCZ format file or not.
     *
     * @return True is a CCZ format file. false is not.
     * @since v3.0
     */
    static bool isCCZFile(const char* filename);

    /**
     * Test the buffer is CCZ format or not.
     *
     * @return True is CCZ format. false is not.
     * @since v3.0
     */
    static bool isCCZBuffer(const unsigned char* buffer, ssize_t len);

    /**
     * Sets the pvr.ccz encryption key parts separately for added security.
     *
     * Example: If the key used to encrypt the pvr.ccz file is
     * 0xaaaaaaaabbbbbbbbccccccccdddddddd you will call this function 4
     * different times, preferably from 4 different source files, as follows
     *
     * ZipUtils::setPvrEncryptionKeyPart(0, 0xaaaaaaaa);
     * ZipUtils::setPvrEncryptionKeyPart(1, 0xbbbbbbbb);
     * ZipUtils::setPvrEncryptionKeyPart(2, 0xcccccccc);
     * ZipUtils::setPvrEncryptionKeyPart(3, 0xdddddddd);
     *
     * Splitting the key into 4 parts and calling the function from 4 different source
     * files increases the difficulty to reverse engineer the encryption key.
     * Be aware that encryption is *never* 100% secure and the key code
     * can be cracked by knowledgable persons.
     *
     * IMPORTANT: Be sure to call setPvrEncryptionKey or
     * setPvrEncryptionKeyPart with all of the key parts *before* loading
     * the sprite sheet or decryption will fail and the sprite sheet
     * will fail to load.
     *
     * @param index Part of the key [0..3].
     * @param value Value of the key part.
     */
    static void setPvrEncryptionKeyPart(int index, unsigned int value);

    /**
     * Sets the pvr.ccz encryption key.
     *
     * Example: If the key used to encrypt the pvr.ccz file is
     * 0xaaaaaaaabbbbbbbbccccccccdddddddd you will call this function with
     * the key split into 4 parts as follows
     *
     * ZipUtils::setPvrEncryptionKey(0xaaaaaaaa, 0xbbbbbbbb, 0xcccccccc, 0xdddddddd);
     *
     * Note that using this function makes it easier to reverse engineer and discover
     * the complete key because the key parts are present in one function call.
     *
     * IMPORTANT: Be sure to call setPvrEncryptionKey or setPvrEncryptionKeyPart
     * with all of the key parts *before* loading the spritesheet or decryption
     * will fail and the sprite sheet will fail to load.
     *
     * @param keyPart1 The key value part 1.
     * @param keyPart2 The key value part 2.
     * @param keyPart3 The key value part 3.
     * @param keyPart4 The key value part 4.
     */
    static void setPvrEncryptionKey(unsigned int keyPart1,
                                    unsigned int keyPart2,
                                    unsigned int keyPart3,
                                    unsigned int keyPart4);

private:
    static int inflateMemoryWithHint(unsigned char* in,
                                     ssize_t inLength,
                                     unsigned char** out,
                                     ssize_t* outLength,
                                     ssize_t outLengthHint);
    static inline void decodeEncodedPvr(unsigned int* data, ssize_t len);
    static inline unsigned int checksumPvr(const unsigned int* data, ssize_t len);

    static unsigned int s_uEncryptedPvrKeyParts[4];
    static unsigned int s_uEncryptionKey[1024];
    static bool s_bEncryptionKeyIsValid;
};

// forward declaration
struct ZipEntryInfo;
struct ZipFilePrivate;

/**
 * Zip file - reader helper class.
 *
 * It will cache the file list of a particular zip file with positions inside an archive,
 * so it would be much faster to read some particular files or to check their existence.
 *
 * @since v2.0.5
 */
class AX_DLL ZipFile
{
public:
    static ZipFile* createFromFile(std::string_view zipFile, std::string_view filter = ""sv);

    virtual ~ZipFile();

    bool initWithFile(std::string_view zipFile, std::string_view filter = ""sv);

    /**
     * Regenerate accessible file list based on a new filter string.
     *
     * @param filter New filter string (first part of files names)
     * @return true whenever zip file is open successfully and it is possible to locate
     *              at least the first file, false otherwise
     *
     * @since v2.0.5
     */
    bool setFilter(std::string_view filter);

    /**
     * Check does a file exists or not in zip file
     *
     * @param fileName File to be checked on existence
     * @return true whenever file exists, false otherwise
     *
     * @since v2.0.5
     */
    bool fileExists(std::string_view fileName) const;

    /**
     * Get files and folders in pathname
     *
     * @param dirname
     * @return
     */
    std::vector<std::string> listFiles(std::string_view pathname) const;

    /**
     * Get resource file data from a zip file.
     * @param fileName File name
     * @param[out] buffer If the file read operation succeeds, if will contain the file data.
     * @return True if successful.
     */
    bool getFileData(std::string_view fileName, ResizableBuffer* buffer);

    std::string getFirstFilename();
    std::string getNextFilename();

    /**
     * zipFile Streaming support, !!!important, the file in zip must no compress level, otherwise
     *  stream seek doesn't work.
     */
    ZipEntryInfo* vopen(std::string_view fileName);
    int vread(ZipEntryInfo*, void* buf, unsigned int size);
    int64_t vseek(ZipEntryInfo*, int64_t offset, int origin);
    void vclose(ZipEntryInfo*);
    int64_t vsize(ZipEntryInfo*);

private:
    ZipFile();

    int getCurrentFileInfo(std::string* filename, unz_file_info_s* info);

    /** Internal data like zip file pointer / file list array and so on */
    ZipFilePrivate* _data;
};

NS_AX_END // end of namespace ax

// end group
/// @}

/// @endcond
#endif  // __SUPPORT_ZIPUTILS_H__