axmol/cocos/base/ZipUtils.h

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Copyright (c) 2017-2018 Xiamen Yaji Software Co., Ltd.

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

#include "platform/CCPlatformMacros.h"
#include "platform/CCFileUtils.h"
#include <string>

#if (CC_TARGET_PLATFORM == CC_PLATFORM_ANDROID)
#include "platform/android/CCFileUtils-android.h"
#elif(CC_TARGET_PLATFORM == CC_PLATFORM_WIN32)
// for import ssize_t on win32 platform
#include "platform/CCStdC.h"
#endif

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

namespace cocos2d
{
#ifndef _unz64_H
typedef struct unz_file_info_s unz_file_info;
#endif
    /** 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 CC_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;
    class ZipFilePrivate;
    struct unz_file_info_s;

    struct ZipFileStream
    {
        ZipEntryInfo* entry;
        long offset;
    };
    /**
    * 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 CC_DLL ZipFile
    {
    public:
        /**
        * Constructor, open zip file and store file list.
        *
        * @param zipFile Zip file name
        * @param filter The first part of file names, which should be accessible.
        *               For example, "assets/". Other files will be missed.
        *
        * @since v2.0.5
        */
        ZipFile(const std::string &zipFile, const std::string &filter = std::string());
        virtual ~ZipFile();

        /**
        * 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(const std::string &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(const std::string &fileName) const;


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


        /**
        * Get resource file data from a zip file.
        * @param fileName File name
        * @param[out] size If the file read operation succeeds, it will be the data size, otherwise 0.
        * @return Upon success, a pointer to the data is returned, otherwise nullptr.
        * @warning Recall: you are responsible for calling free() on any Non-nullptr pointer returned.
        *
        * @since v2.0.5
        */
        unsigned char *getFileData(const std::string &fileName, ssize_t *size);
        
        /**
        * 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(const std::string &fileName, ResizableBuffer* buffer);

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

        static ZipFile *createWithBuffer(const void* buffer, unsigned long size);

        /**
        * zipFile Streaming support, !!!important, the file in zip must no compress level, otherwise
        *  stream seek doesn't work.
        */
        bool zfopen(const std::string& fileName, ZipFileStream* zfs);
        int zfread(ZipFileStream* zfs, void* buf, unsigned int size);
        long zfseek(ZipFileStream* zfs, long offset, int origin);
        void zfclose(ZipFileStream* zfs);
        
    private:
        /* Only used internal for createWithBuffer() */
        ZipFile();
        
        bool initWithBuffer(const void *buffer, unsigned long size);
        int getCurrentFileInfo(std::string *filename, unz_file_info *info);
        
        /** Internal data like zip file pointer / file list array and so on */
        ZipFilePrivate *_data;
    };
} // end of namespace cocos2d

// end group
/// @}

/// @endcond
#endif // __SUPPORT_ZIPUTILS_H__