[原创]BUUCTF逆向题：特殊的 BASE64-CTF对抗-看雪-安全社区|安全招聘|kanxue.com

[原创]BUUCTF逆向题：特殊的 BASE64

发表于: 2022-3-27 18:09 5543

[原创]BUUCTF逆向题：特殊的 BASE64

宇宙大魔王

2022-3-27 18:09

5543

1.基本信息探查：

1.EXEinfo：

2.运行一下：

2.IDA分析：

1.主函数分析：

int __cdecl main(int argc, const char **argv, const char **envp)
{
  __int64 v3; // rax
  __int64 v4; // rax
  std::string result; // [rsp+20h] [rbp-60h] BYREF
  std::string rightFlag; // [rsp+30h] [rbp-50h] BYREF
  std::string str; // [rsp+40h] [rbp-40h] BYREF
  char v9; // [rsp+4Fh] [rbp-31h] BYREF
  std::string v10; // [rsp+50h] [rbp-30h] BYREF
 
  _main();
  std::string::string(&str);
  std::allocator<char>::allocator(&v9);
  std::string::string(&rightFlag, "mTyqm7wjODkrNLcWl0eqO8K8gc1BPk1GNLgUpI==", &v9);
  std::allocator<char>::~allocator(&v9);
  v3 = std::operator<<<std::char_traits<char>>(refptr__ZSt4cout, "Please input your flag!!!!");
  std::ostream::operator<<(v3, refptr__ZSt4endlIcSt11char_traitsIcEERSt13basic_ostreamIT_T0_ES6_);
  std::operator>><char>(refptr__ZSt3cin, &str);
  std::string::string(&v10, &str);
  base64Encode(&result);                //调用base64Encode函数
  std::string::~string(&v10);
  if ( std::operator==<char>(&result, &rightFlag) )     //字符串的比较
    v4 = std::operator<<<std::char_traits<char>>(refptr__ZSt4cout, "The flag is right!!!!!!!!!");
  else
    v4 = std::operator<<<std::char_traits<char>>(refptr__ZSt4cout, "This is a wrong flag!!!!!!!!");
  std::ostream::operator<<(v4, refptr__ZSt4endlIcSt11char_traitsIcEERSt13basic_ostreamIT_T0_ES6_);
  std::string::~string(&result);
  std::string::~string(&rightFlag);
  std::string::~string(&str);
  return 0;
}