CSAW - rock - rev 100

gistfile1.py

# @_hugsy_
# $ python bf.py
# Pass 0
# [...]
# Pass 27
# Pass 28
# Pass 29
# /////////////////////////////////
# Do not be angry. Happy Hacking :)
# /////////////////////////////////
# Flag{IoDJuvwxy\tuvyxwxvwzx{\z{vwxyz}

from pwn import *
import string

context.log_level = "critical"


def guess_char(prefix, i):
    for c in string.printable:
        r = process("./rock")
        line = prefix + c + "A"*(29-len(prefix))
        r.sendline(line)
        r.recvuntil("Checking....\n")
        l = r.recv(1024)
        if "Pass %d"%i in l:
            print l
            r.close()
            return c
        r.close()
    return ""

f = ""
for i in range(30):
    c = guess_char(f, i)
    if c == "":
        raise Exception("fooooooo")
    f+= c
    print f