Reversing Challenge.Challenge binary from TryHackMe's room Classic Passwd using Ghidra

passwd.c

// https://0xsanz.medium.com/classic-passwd-tryhackme-60b2ad5c5008
undefined8 main(void)

{
  vuln();
  gfl();
  return 0;
}


void vuln(void)

{
  int iVar1;
  char local_2c8 [130];
  undefined8 local_246;
  undefined4 local_23e;
  undefined2 local_23a;
  char local_238 [512];
  undefined8 local_38;
  undefined8 local_30;
  undefined8 local_28;
  undefined2 local_20;
  undefined local_1e;
  undefined8 local_15;
  undefined4 local_d;
  undefined local_9;
  
  local_15 = 0x207962206564614d;
  local_d = 0x6e6f6e34;
  local_9 = 0;
  local_38 = 0x2f2f3a7370747468;
  local_30 = 0x632e627568746967;
  local_28 = 0x69626f306e2f6d6f;
  local_20 = 0x3474;
  local_1e = 0;
  local_246 = 0x6435736a36424741;
  local_23e = 0x476b6439;
  local_23a = 0x37;
  printf("Insert your username: ");
  __isoc99_scanf(&DAT_0010201b,local_238);
  strcpy(local_2c8,local_238);
  iVar1 = strcmp(local_2c8,(char *)&local_246);
  if (iVar1 == 0) {
    puts("\nWelcome");
    return;
  }
  puts("\nAuthentication Error");
                    /* WARNING: Subroutine does not return */
  exit(0);
}


void gfl(void)

{
  int local_10;
  int local_c;
  
  local_c = 0x52c8d5;
  do {
    if (0x77d088 < local_c) {
      return;
    }
    if (local_c == 0x638a78) {
      local_10 = 0x1474;
      while (local_10 < 9999) {
        if (local_10 == 0x2130) {
          printf("THM{%d%d}",0x638a78,0x2130);
                    /* WARNING: Subroutine does not return */
          exit(0);
        }
        local_10 = local_10 + 1;
      }
    }
    local_c = local_c + 1;
  } while( true );
}