GFSJ0366-【reverse-for-the-holy-grail-350】

int __fastcall main(int argc, const char **argv, const char **envp)
{
  int valid; // ebx
  int v4; // ebx
  __int64 v5; // rbx
  void *v7[2]; // [rsp+0h] [rbp-70h] BYREF
  _BYTE v8[16]; // [rsp+10h] [rbp-60h] BYREF
  void *v9[2]; // [rsp+20h] [rbp-50h] BYREF
  _BYTE v10[16]; // [rsp+30h] [rbp-40h] BYREF
  void *v11[2]; // [rsp+40h] [rbp-30h] BYREF
  _BYTE v12[24]; // [rsp+50h] [rbp-20h] BYREF

  v11[0] = v12;
  v11[1] = nullptr;
  v12[0] = 0;
  std::__ostream_insert<char,std::char_traits<char>>(&std::cout, "What... is your name?", 21);
  std::endl<char,std::char_traits<char>>(&std::cout);
  std::operator>><char>(&std::cin, v11);
  std::__ostream_insert<char,std::char_traits<char>>(&std::cout, "What... is your quest?", 22);
  std::endl<char,std::char_traits<char>>(&std::cout);
  std::istream::ignore((std::istream *)&std::cin);
  std::getline<char,std::char_traits<char>,std::allocator<char>>(&std::cin, v11);
  std::__ostream_insert<char,std::char_traits<char>>(&std::cout, "What...  is the secret password?", 32);
  std::endl<char,std::char_traits<char>>(&std::cout);
  std::operator>><char>(&std::cin, &userIn[abi:cxx11]);
  v7[0] = v8;
  std::string::_M_construct<char *>(v7, userIn[abi:cxx11], qword_601AE8 + userIn[abi:cxx11]);
  valid = validChars(v7);
  if ( v7[0] != v8 )
    operator delete(v7[0]);
  if ( valid < 0 )
    goto LABEL_8;
  v9[0] = v10;
  std::string::_M_construct<char *>(v9, userIn[abi:cxx11], qword_601AE8 + userIn[abi:cxx11]);
  v4 = stringMod(v9);
  if ( v9[0] != v10 )
    operator delete(v9[0]);
  if ( v4 < 0 )
  {
LABEL_8:
    std::__ostream_insert<char,std::char_traits<char>>(&std::cout, "Auuuuuuuugh", 11);
    std::endl<char,std::char_traits<char>>(&std::cout);
  }
  else
  {
    std::__ostream_insert<char,std::char_traits<char>>(&std::cout, "Go on. Off you go. tuctf{", 25);
    v5 = std::__ostream_insert<char,std::char_traits<char>>(&std::cout, userIn[abi:cxx11], qword_601AE8);
    std::__ostream_insert<char,std::char_traits<char>>(v5, "}", 1);
    std::endl<char,std::char_traits<char>>(v5);
  }
  if ( v11[0] != v12 )
    operator delete(v11[0]);
  return 0;
}

__int64 __fastcall stringMod(__int64 *a1)
{
  __int64 v1; // r9
  __int64 v2; // r10
  __int64 v3; // rcx
  int v4; // r8d
  _DWORD *v5; // rdi
  __int64 *v6; // rsi
  int v7; // ecx
  int v8; // r9d
  int v9; // r10d
  unsigned int v10; // eax
  int v11; // esi
  int v12; // esi
  _DWORD v14[18]; // [rsp+0h] [rbp-60h] BYREF
  __int64 v15; // [rsp+48h] [rbp-18h] BYREF

  memset(v14, 0, sizeof(v14));
  v1 = a1[1];
  if ( v1 )
  {
    v2 = *a1;
    v3 = 0;
    v4 = 0;
    do
    {
      v12 = *(char *)(v2 + v3);
      v14[v3] = v12;
      if ( 3 * ((unsigned int)v3 / 3) == (_DWORD)v3 && v12 != firstchar[(unsigned int)v3 / 3] )
        v4 = -1;
      ++v3;
    }
    while ( v3 != v1 );
  }
  else
  {
    v4 = 0;
  }
  v5 = v14;
  v6 = (__int64 *)v14;
  v7 = 666;
  do
  {
    *(_DWORD *)v6 = v7 ^ *(unsigned __int8 *)v6;
    v7 += v7 % 5;
    v6 = (__int64 *)((char *)v6 + 4);
  }
  while ( &v15 != v6 );
  v8 = 1;
  v9 = 0;
  v10 = 1;
  v11 = 0;
  do
  {
    if ( v11 == 2 )
    {
      if ( *v5 != thirdchar[v9] )
        v4 = -1;
      if ( v10 % *v5 != masterArray[v9] )
        v4 = -1;
      ++v9;
      v10 = 1;
      v11 = 0;
    }
    else
    {
      v10 *= *v5;
      if ( ++v11 == 3 )
        v11 = 0;
    }
    ++v8;
    ++v5;
  }
  while ( v8 != 19 );
  return (unsigned int)(v7 * v4);
}

password[3*i]     = firstchar[i]
(password[3*i] ^ key[3*i]) * (password[3*i+1] ^ key[3*i+1])
    % thirdchar[i] == masterArray[i]
password[3*i+2] ^ key[3*i+2] == thirdchar[i]

firstchar = [65, 105, 110, 69, 111, 97]
thirdchar = [751, 708, 732, 711, 734, 764]
masterArray = [471, 12, 580, 606, 147, 108]

first = [65, 105, 110, 69, 111, 97]
third = [751, 708, 732, 711, 734, 764]
master = [471, 12, 580, 606, 147, 108]

k = []
x = 666
for _ in range(18):
    k.append(x)
    x += x % 5

flag = ""

for i in range(6):
    a = first[i]
    c = k[i * 3 + 2] ^ third[i]

    for b in range(32, 127):
        if ((a ^ k[i * 3]) * (b ^ k[i * 3 + 1])) % third[i] == master[i]:
            flag += chr(a) + chr(b) + chr(c)
            break

print(f"tuctf{{{flag}}}")

tuctf{AfricanOrEuropean?}