Python code not stopping, getting stuck at a certain point

Question

I have written a small piece of code to encrypt a file and decrypt it. However It is getting stuck somewhere, I think it is after it initially decrypts it as it creates the encrypted file but does not print 'Encrypted!'. What am I doing wrong? Is it one of the loops?

Code:

from hashlib import md5
from Crypto import Random
from Crypto.Cipher import AES
import os
from Crypto import *

def encrypt(in_file, out_file, key, iv):
    bs = AES.block_size
    cipher = AES.new(key, AES.MODE_CBC, iv)
    finished = False
    print('check001')
    while not finished:
     chunk = in_file.read(1024 * bs)
     print('check002')
    if len(chunk) == 0 or len(chunk) % bs != 0:
        padding_length = bs - (len(chunk) % bs)
        chunk += padding_length * chr(padding_length)
        finished = True
        out_file.write(cipher.encrypt(chunk))
        print('check003')

def decrypt(in_file, out_file, key, iv):
    bs = AES.block_size
    cipher = AES.new(key, AES.MODE_CBC, iv)
    next_chunk = ''
    finished = False
    while not finished:
        chunk, next_chunk = next_chunk, cipher.decrypt(in_file.read(1024 * bs))
        if len(next_chunk) == 0:
            padding_length = ord(chunk[-1])
        if padding_length < 1 or padding_length > bs:
            raise ValueError("bad decrypt pad (%d)" % padding_length)
        if chunk[-padding_length:] != (padding_length * chr(padding_length)):
            raise ValueError("bad decrypt")
        chunk = chunk[:-padding_length]
        finished = True
    out_file.write(chunk)

encFile= input('Enter the path of the file you would like to encrypt: ')
doneFile= encFile + '.enc'
unFile = encFile + '.dec'

in_file = open(encFile, 'rb')
print('check004')
out_file = open(doneFile, 'wb')
print('check005')
key = os.urandom(32)
iv = os.urandom(16)
print('check006')
encrypt(in_file, out_file, key, iv)
print('check007')
in_file.close()
out_file.close()
print('Encrypted!')

in_file = open(doneFile, 'rb')
out_file = open(unFile, 'wb')
decrypt(in_file, out_file, key, iv)
in_file.close()
out_file.close()
print('Decrypted!')

Answer 1

This might just be a mistake in posting the code to the question, but the indentation looks incorrect:

while not finished:
 chunk = in_file.read(1024 * bs)
if len(chunk) == 0 or len(chunk) % bs != 0:
    padding_length = bs - (len(chunk) % bs)
    chunk += padding_length * chr(padding_length)
    finished = True
    out_file.write(cipher.encrypt(chunk))

shouldn't the if statement be indented to be:

while not finished:
 chunk = in_file.read(1024 * bs)
 if len(chunk) == 0 or len(chunk) % bs != 0:
    padding_length = bs - (len(chunk) % bs)
    chunk += padding_length * chr(padding_length)
    finished = True
    out_file.write(cipher.encrypt(chunk))

otherwise you are forever reading in