Cocos图片加密与解密

#!/usr/bin/env python
#coding=utf-8
# 2019-12-28 by LeiTao
#
import sys
import os

FileEncrpyEnum = { 
   ".png"}  #这里填入你需要加密图片的后缀名，这里我只加密png
EncrpyKey = 58   #异或加密秘钥
HeadSize = 8	 #添加8个byte在文件头
EncrySize = 100  #为了更快的解密,只加密文件的100个字节流
def MakeEncrpy(pahtName,FileName):
	oldfile = open(os.path.join(pahtName, FileName),'rb')
	oldConten = oldfile.read()
	oldfile.close()

	li_out=[]
	#添加加密标识
	for index in range(HeadSize):
		li_out.append(chr(0x01))

	for i in range(len(oldConten)):
		if i < EncrySize:
			li_out.append(chr(ord(oldConten[i])^EncrpyKey)) #异或Key进行加密
		else:
			li_out.append(chr(ord(oldConten[i])))
	newfile = open(os.path.join(pahtName, FileName), 'wb')
	newfile.truncate()
	newfile.write(''.join(li_out))
	newfile.close()
	return
	
def main():
	dirPath = sys.argv[1]
	print dirPath
	print "==============GameEncrpy Begin"
	for root, dirs, files in os.walk(dirPath):

        # root 表示当前正在访问的文件夹路径
        # dirs 表示该文件夹下的子目录名list
        # files 表示该文件夹下的文件list
        # 遍历文件
   		for f in files:
   			ExtensionName = os.path.splitext(f)[1]
   			if ExtensionName in FileEncrpyEnum :
				MakeEncrpy(root,f)

	print "==============GameEncrpy End"


# -------------- main --------------
if __name__ == '__main__':
	try:
		main()
	except Exception as e:
		sys.exit(1)

static Data getData(const std::string& filename, bool forString)
{ 
   
    if (filename.empty())
    { 
   
        return Data::Null;
    }
	CCLOG("FileUtils getData Now"); 
    Data ret;
    unsigned char* buffer = nullptr;
    size_t size = 0;
    size_t readsize;
    const char* mode = nullptr;

    if (forString)
        mode = "rt";
    else
        mode = "rb";

    auto fileutils = FileUtils::getInstance();
    do
    { 
   
        // Read the file from hardware
        std::string fullPath = fileutils->fullPathForFilename(filename);
        FILE *fp = fopen(fileutils->getSuitableFOpen(fullPath).c_str(), mode);
        CC_BREAK_IF(!fp);
        fseek(fp,0,SEEK_END);
        size = ftell(fp);
        fseek(fp,0,SEEK_SET);

        if (forString)
        { 
   
            buffer = (unsigned char*)malloc(sizeof(unsigned char) * (size + 1));
            buffer[size] = '\0';
        }
        else
        { 
   
            buffer = (unsigned char*)malloc(sizeof(unsigned char) * size);
        }

        readsize = fread(buffer, sizeof(unsigned char), size, fp);
        fclose(fp);

        if (forString && readsize < size)
        { 
   
            buffer[readsize] = '\0';
        }
    } while (0);

    if (nullptr == buffer || 0 == readsize)
    { 
   
        CCLOG("Get data from file %s failed", filename.c_str());
    }
    else
    { 
   
    	//这里实际上就是最终文件读取后的buffer
    	//所以我们需要再这里进行校验文件是否需要解密
    	///
		//检查是否需要解密
		std::string::size_type index = fullPath.find_last_of(".") + 1;
		std::string fileType = fullPath.substr(index, fullPath.length() - index);
		if(fileType.compare("png")==0)  //png类型进行解密
		{ 
   
			CCLOG("Decode Now");
			unsigned char encry_head[8] = { 
    0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01};//添加的头
			size_t HeadSize = 8;
			if (memcmp(buffer, encry_head, HeadSize) == 0) //比较是否我们添加的头，来判断是否需要解密
			{ 
   
				int Key = 58;
				int EncrySize = 100;
				
				unsigned char *new_buffer = nullptr;
				if (forString)
				{ 
   
					new_buffer = (unsigned char*)malloc(size - HeadSize + 1);
					new_buffer[size - HeadSize] = '\0';
				}
				else
				{ 
   
					new_buffer = (unsigned char*)malloc(size - HeadSize);
				}
				for (int i = HeadSize; i < size; i++) { 
   

					if (i < EncrySize + HeadSize) { 
     //加密部分进行解密
						new_buffer[i - HeadSize] = buffer[i] ^ Key; //异或Key进行解密
					}
					else { 
   
						new_buffer[i - HeadSize] = buffer[i];
					}
				}
				free(buffer);
				buffer = new_buffer;
				size = size - HeadSize;  //去掉加密头长度
			}
		}
        ret.fastSet(buffer, readsize);
    }

    return ret;
}