babyre.py

from pwn import *
import string

payload=string.printable[:-5]

enc_payload=[]

t=len(payload)/30
t=int(t)+1
for i in range(t):
  io=process('./babyre')
  sleep(0.1)
  io.sendline('15')
  sleep(0.1)
  io.sendline('15')
  sleep(0.1)
  data=payload[i*30:i*30+30]
  io.sendline(data)
  for j in range(len(data)):
    enc_payload.append(io.recvline().strip()[-8:])
  io.close()

enc=open('out','r').read().lower()
enc=enc.replace('\n','').replace('\r','')

flag=''
for i in range(len(enc)/8):
  pos=enc_payload.index(enc[i*8:i*8+8])
  flag+=payload[pos]
print flag