攻防世界-reverse-666

Posted 2021-02-20 banpingcu

加密代码

int __fastcall encode(const char *a1, __int64 a2)
{
  char v3[32]; // [rsp+10h] [rbp-70h]
  char v4[32]; // [rsp+30h] [rbp-50h]
  char v5[40]; // [rsp+50h] [rbp-30h]
  int v6; // [rsp+78h] [rbp-8h]
  int i; // [rsp+7Ch] [rbp-4h]

  i = 0;
  v6 = 0;
  if ( strlen(a1) != key )
    return puts("Your Length is Wrong");
  for ( i = 0; i < key; i += 3 )
  {
    v5[i] = key ^ (a1[i] + 6);
    v4[i + 1] = (a1[i + 1] - 6) ^ key;
    v3[i + 2] = a1[i + 2] ^ 6 ^ key;
    *(_BYTE *)(a2 + i) = v5[i];
    *(_BYTE *)(a2 + i + 1LL) = v4[i + 1];
    *(_BYTE *)(a2 + i + 2LL) = v3[i + 2];
  }
  return a2;
}

db="izwhroz""w"v.K".Ni"
flag=‘‘
for i in range(0,18,3):
    flag+=chr((18^ord(db[i]))-6)
    flag+=chr((18^ord(db[i+1]))+6)
    flag+=chr(18^ord(db[i+2])^6)    
print(flag)

unctf{b66_6b6_66b}