The crypto was a simple substitution cipher over the printable characters. After running it 50 times, the flag was printed
```

import socket

class Netcat:

""" Python 'netcat like' module """

def __init__(self, ip, port):

self.buff = ""
self.socket = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
self.socket.connect((ip, port))

def read(self, length = 1024):

""" Read 1024 bytes off the socket """

return self.socket.recv(length)

def read_until(self, data):

""" Read data into the buffer until we have data """

while not data in self.buff:
self.buff += self.socket.recv(1024)

pos = self.buff.find(data)
rval = self.buff[:pos + len(data)]
self.buff = self.buff[pos + len(data):]

return rval

def write(self, data):

self.socket.send(data)

def close(self):

self.socket.close()

# below is a extract from a sample exploit that
# interfaces with a tcp socket
print "YES"
# start a new Netcat() instance
nc = Netcat('neverending.tuctf.com', 12345)
while True:
print nc.read()
nc.write(" \n")
x=nc.read().split("is ")
b=ord(x[1][0])
ble=b-32
yo=x[2].split(" d")[0]
s=""
for i in yo:
ye=ord(i)-ble
if ye<32:
ye=ye-32+127
s=s+chr(ye)
print s
nc.write(s+"\n")

```