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main函数代码

void __fastcall __noreturn main(int a1, char **a2, char **a3)
{
  size_t v3; // rsi
  int i; // [rsp+3Ch] [rbp-54h]
  char s[36]; // [rsp+40h] [rbp-50h] BYREF
  int n7; // [rsp+64h] [rbp-2Ch]``
  __int64 v7; // [rsp+68h] [rbp-28h]
  char v1[28]; // [rsp+70h] [rbp-20h] BYREF
  int v9; // [rsp+8Ch] [rbp-4h]
  v9 = 0;
  strcpy(v1, ":\"AL_RT^L*.?+6/46");
  v7 = 0x65626D61726168LL;
  n7 = 7;
  printf("Welcome to the RC3 secure password guesser.\n");
  printf("To continue, you must enter the correct password.\n");
  printf("Enter your guess: ");
  __isoc99_scanf("%32s", s);
  v3 = strlen(s);
  if ( v3 < strlen(v1) )
    sub_4007C0();
  for ( i = 0; i < strlen(s); ++i )
  {
    if ( i >= strlen(v1) )
      sub_4007C0();
    if ( s[i] != (char)(v1[i % n7 - 8] ^ v1[i]) )
      sub_4007C0();
  }
  sub_4007F0();
}

v1和v7的内存是连在一起的，所以v1[i % n7 - 8] 就相当于v7[i] 所以解密代码是

a=r':"AL_RT^L*.?+6/46'
key='harambe'
flag=''
b=[0]*len(a)
for i in range(len(a)):
    b[i]=ord(a[i])^ord(key[i%7])
    flag+=chr(b[i])
print(flag)