求助大佬们，某三国游戏解密

[edolia]

游戏下载链接：https://yjsg.gamecomb.com/

读so后找到了这个函数EJ::EJAES::DecryptFile，但是文件字节不满足

然后加密的文件有统一的文件头，看起来又像xxtea，我使用里面硬编码的密匙也解不开

这是加密后的样本，为pvr.ccz格式
样本.zip (175.2 KB)
谢谢~

[yjzyl9008]

只对前32个字节进行了两轮循环异或

参考加密函数可以得知

int __fastcall cocos2d::CCFileUtils::encrypt(cocos2d::CCFileUtils *this, char *a2, unsigned int a3)
{
  int v4; // r0
  int v5; // r3
  bool v6; // cc
  int v8; // [sp+0h] [bp-28h]
  char v10[4]; // [sp+8h] [bp-20h] BYREF
  int v11; // [sp+Ch] [bp-1Ch]
  int v12; // [sp+10h] [bp-18h]
  int v13; // [sp+14h] [bp-14h]
  int v14; // [sp+18h] [bp-10h]

  if ( *((_BYTE *)this + 44) )
  {
    v13 = 0;
    v12 = 0;
    v11 = 0;
    *(_DWORD *)v10 = 0;
    strncpy(v10, *((const char **)this + 10), 0x10u);
    v4 = 0;
    v8 = 0;
LABEL_3:
    v5 = 0;
    while ( v4 + v5 < a3 )
    {
      a2[v4 + v5] ^= v10[v5];
      v6 = v5++ < 15;
      if ( !v6 )
      {
        v4 += 16;
        v6 = v8++ < 1;
        if ( v6 )
          goto LABEL_3;
        return _stack_chk_guard - v14;
      }
    }
  }
  return _stack_chk_guard - v14;
}

解密函数如下：

def decrypt_file(input_file, output_file, key="wzwlqyyl2013win"):
    key = key.ljust(16, '\0')[:16]
    key_bytes = key.encode('utf-8')
    
    with open(input_file, 'rb') as f_in:
        data = bytearray(f_in.read())
    
    for i in range(min(32, len(data))):
        data[i] ^= key_bytes[i % 16]
    
    with open(output_file, 'wb') as f_out:
        f_out.write(data)
    
    return True

if __name__ == "__main__":
    import sys
    input_file = sys.argv[1]
    output_file = sys.argv[2]
    decrypt_file(input_file, output_file)

需要用TexturePacker之类的打开并转换图片

[edolia]

好滴，谢谢大佬~