Unity的windows版本Assembly-CSharp.dll的加密实现

小鱼儿 2023-10-17 18:03 14阅读 0赞

转载自:[http://blog.csdn.net/glunoy/article/details/62231825][http_blog.csdn.net_glunoy_article_details_62231825]  
加密Unity的windows版本Assembly-CSharp.dll的实现  
原创 2017年03月15日 17:28:15 标签：Unity3d 1755  
参考文章：  
[http://www.cppcourse.com/u3d-encryption.html][http_www.cppcourse.com_u3d-encryption.html]  
[http://www.cnblogs.com/lixiang-share/p/5979981.html][http_www.cnblogs.com_lixiang-share_p_5979981.html]

1.先到[https://github.com/Unity-Technologies/mono][https_github.com_Unity-Technologies_mono] 下载版本对应的分支。我的是[https://github.com/Unity-Technologies/mono/tree/unity-5.5][https_github.com_Unity-Technologies_mono_tree_unity-5.5]  
2.解压文件，进入msvc文件夹，可以看到它的工程目录用的是vs2010. 为了避免各种问题，我们也使用VS2010来编译。  
3.选择Release\_eglib，执行编译。不一会，编译成功。先不要急着搞什么加密代码。用此mono.dll 替换你生成的exe下的xx\_Data/Mono/mono.dll  
如果运行不成功，说明你下到了错误的分支。运行成功继续步骤4.  
4.先到以上参考文章中提到的xxtea中下载源码。创建任意控制台程序并加入此xxtea.c xxtea.h编写如下程序。

#include "stdafx.h"  
    
    #include <stdio.h>  
    #include <string.h>  
    #include <stdlib.h>  
    #include "xxtea.h"  
    
    #define SIZE 1024*1024*10  
    
    int Decrypt()   
    {  
        FILE *infp = 0;//判断命令行是否正确  
        if ((infp = fopen("Assembly-CSharp_encrypt.dll", "rb")) == NULL)  
        {  
            printf("Assembly-CSharp.dll Read Error\n");//打开操作不成功  
            return 0;//结束程序的执行  
        }  
    
        //char buffer[SIZE];  
        char* buffer = (char*)malloc(sizeof(char)*SIZE);  
        memset(buffer, 0, sizeof(char)*SIZE);  
    
        int rc = 0;  
        int total_len = 0;  
    
        total_len = fread(buffer, sizeof(unsigned char), SIZE, infp);  
        printf("Read Assembly-CSharp Successfully and total_len : %d \n", total_len);  
    
        //加密DLL  
        size_t len;  
        char* key = "123456";  
        char *decrypt_data = (char*)xxtea_decrypt(buffer, total_len, key, &len);  
    
        printf("Encrypt Dll Successfully and len : %d\n", len);  
    
        //写Dll  
        FILE* outfp = 0;  
        if ((outfp = fopen("Assembly-CSharp_decrypt.dll", "wb+")) == NULL)  
        {  
            printf("Assembly-CSharp_encrypt.dll Read Error\n");//打开操作不成功  
            return 0;//结束程序的执行  
        }  
    
        int rstCount = fwrite(decrypt_data, sizeof(unsigned char), len, outfp);  
    
        fflush(outfp);  
    
        printf("Write len : %d\n", rstCount);  
    
        fclose(infp);  
        fclose(outfp);  
    
        free(buffer);  
        free(decrypt_data);  
    }  
    
    int main() //命令行参数  
    {  
        FILE *infp = 0;//判断命令行是否正确  
        if ((infp = fopen("Assembly-CSharp.dll", "rb")) == NULL)  
        {  
            printf("Assembly-CSharp.dll Read Error\n");//打开操作不成功  
            return 0;//结束程序的执行  
        }  
    
        //char buffer[SIZE];  
        char* buffer = (char*)malloc(sizeof(char)*SIZE);  
        memset(buffer, 0, sizeof(char)*SIZE);  
    
        int rc = 0;  
        int total_len = 0;  
    
        total_len = fread(buffer, sizeof(unsigned char), SIZE, infp);  
        printf("Read Assembly-CSharp Successfully and total_len : %d \n", total_len);  
    
        //加密DLL  
        size_t len;  
        char* key = "123456";  
        char *encrypt_data = (char*)xxtea_encrypt(buffer, total_len, key, &len);  
    
        printf("Encrypt Dll Successfully and len : %d\n", len);  
    
        //写Dll  
        FILE* outfp = 0;  
        if ((outfp = fopen("Assembly-CSharp_encrypt.dll", "wb+")) == NULL)  
        {  
            printf("Assembly-CSharp_encrypt.dll Read Error\n");//打开操作不成功  
            return 0;//结束程序的执行  
        }  
    
        int rstCount = fwrite(encrypt_data, sizeof(unsigned char), len, outfp);  
    
        fflush(outfp);  
    
        printf("Write len : %d\n", rstCount);  
    
        fclose(infp);  
        fclose(outfp);  
    
        free(buffer);  
        free(encrypt_data);  
    
        //test decrpyt  
        {  
            Decrypt();  
        }  
    
    
        return 0;  
    }

5.编译，并将要加密的Assembly-CSharp.dll 放到生成的exe目录下，执行双击。 OK 现在你可以看到有  
Assembly-CSharp\_decrypt.dll  
Assembly-CSharp\_encrypt.dll  
使用任意文件对比工具，检查  
Assembly-CSharp.dll  
Assembly-CSharp\_decrypt.dll  
完全匹配。OK。说明加密解密均没问题。

6.切换回mono源码目录 将xxtea.c xxtea.h放入mono-unity-5.5\\mono\\metadata 下，并将2个文件加入工程。  
7.打开mono-unity-5.5/mono/metadata/image.c  
加入如下2行代码

#include <stdlib.h>
    #include "mono/metadata/xxtea.h"

定位到mono\_image\_open\_from\_data\_with\_name  
在data检查是否为空 return null的下面 加入

if(strstr(name ,"Assembly-CSharp.dll")){  
    
            char* key = "123456";  
            size_t len;  
            char* decryptData = (char*)xxtea_decrypt(data , data_len, key, &len);//换成对应的解密函数  
            int i = 0;  
            for ( i = 0; i < len; ++i)  
            {  
              data[i] = decryptData[i];  
            }  
            g_free(decryptData);  
        data_len = len;  
        }

OK，编译。mono-unity-5.5\\builds\\embedruntimes\\win32 下的mono.dll 替换掉我们的xx\_Data/Mono/mono.dll。将上文生成的Assembly-CSharp\_encrypt.dll，改名Assembly-CSharp.dll覆盖掉xx\_Data\\Managed\\Assembly-CSharp.dll

运行游戏，可以看到稍微卡了一下，然后游戏正常执行。至此加密完毕。  
==========================这是用于商业游戏的情况下加密源码======================  
本人希望各位兄弟前辈们积极开源一些不重要的工程，方便后来人提高技术，这样才有良好的技术环境。  
这也是撰写本文的初衷。谢谢大家

[http_blog.csdn.net_glunoy_article_details_62231825]: http://blog.csdn.net/glunoy/article/details/62231825
[http_www.cppcourse.com_u3d-encryption.html]: http://www.cppcourse.com/u3d-encryption.html
[http_www.cnblogs.com_lixiang-share_p_5979981.html]: http://www.cnblogs.com/lixiang-share/p/5979981.html
[https_github.com_Unity-Technologies_mono]: https://github.com/Unity-Technologies/mono
[https_github.com_Unity-Technologies_mono_tree_unity-5.5]: https://github.com/Unity-Technologies/mono/tree/unity-5.5