Develop Reference

some problems of using Python's Cryptography on Windows

I would like to use the cryptography's module on Windows, I am using version 1.12 and Python 3.10.6, and I have some problems. Actually, when I run my script, I receive the error :
`
Traceback (most recent call last):
File "C:/Users/edoua/Documents/cryptographie.py", line 1, in <module>
from cryptography.fernet import Fernet
File "C:\Users\edoua\AppData\Local\Programs\Python\Python310\lib\site-packages\cryptography\fernet.py", line 16, in <module>
from cryptography.hazmat.primitives.hmac import HMAC
File "C:\Users\edoua\AppData\Local\Programs\Python\Python310\lib\site-packages\cryptography\hazmat\primitives\hmac.py", line 10, in <module>
from cryptography.hazmat.backends.openssl.hmac import _HMACContext
File "C:\Users\edoua\AppData\Local\Programs\Python\Python310\lib\site-packages\cryptography\hazmat\backends\openssl\__init__.py", line 6, in <module>
from cryptography.hazmat.backends.openssl.backend import backend
File "C:\Users\edoua\AppData\Local\Programs\Python\Python310\lib\site-packages\cryptography\hazmat\backends\openssl\backend.py", line 13, in <module>
from cryptography import utils, x509
File "C:\Users\edoua\AppData\Local\Programs\Python\Python310\lib\site-packages\cryptography\x509\__init__.py", line 7, in <module>
from cryptography.x509.base import (
File "C:\Users\edoua\AppData\Local\Programs\Python\Python310\lib\site-packages\cryptography\x509\base.py", line 28, in <module>
from cryptography.x509.extensions import (
File "C:\Users\edoua\AppData\Local\Programs\Python\Python310\lib\site-packages\cryptography\x509\extensions.py", line 25, in <module>
from cryptography.x509.general_name import (
File "C:\Users\edoua\AppData\Local\Programs\Python\Python310\lib\site-packages\cryptography\x509\general_name.py", line 9, in <module>
from email.utils import parseaddr
File "C:\Users/edoua/Documents\email.py", line 18, in <module>
server.login(email_address, email_password)
File "C:\Users\edoua\AppData\Local\Programs\Python\Python310\lib\smtplib.py", line 739, in login
(code, resp) = self.auth(
File "C:\Users\edoua\AppData\Local\Programs\Python\Python310\lib\smtplib.py", line 641, in auth
response = encode_base64(initial_response.encode('ascii'), eol='')
NameError: name 'encode_base64' is not defined
`
It is coming from the smtplib.py file. Also, I precise that the module works perfectly, I can use all the functions of the module base64. So the problem is coming from the word 'encode_base64'. Please help !
I tried to launch my program, and that error occures, I expected that it was going to work.

You have a local module C:\Users/edoua/Documents\email.py that is shadowing the email module from the Python standard library. Rename email.py to something else, or move it to somewhere that isn't on the Python path.

Error in pox controller in sdn using python2 and python3 for detectionEntropy

I am trying to run pox controller using the command
python2 ./pox.py forwarding.​ l3_detectionEntropyemphasized text
Then I got this error.
` Traceback (most recent call last):
File "./pox.py", line 43, in <module>
from pox.boot import boot
File "/home/name/pox/pox/boot.py", line 38, in <module>
import pox.core
File "/home/name/pox/pox/core.py", line 182, in <module>
import pox.lib.recoco as recoco
File "/home/name/pox/pox/lib/recoco/__init__.py", line 1, in <module>
from .recoco import *
File "/home/name/pox/pox/lib/recoco/recoco.py", line 17, in <module>
from queue import PriorityQueue
ImportError: No module named queue`
Also I have tried to run it in python3 by converting it into python3 Then i got this error.
`Traceback (most recent call last):
File "/home/shivani/pox/pox/boot.py", line 74, in do_import2
__import__(name, level=0)
File "/home/shivani/pox/pox/forwarding/l3_detectionEntropy.py", line 129
print "dpid port and its packet count: ", str(event.connection.dpid),
str(diction[event.connection.dpid]), str(diction[event.connection.dpid][event.port])
^
SyntaxError: invalid syntax
Could not import module: forwarding.l3_detectionEntropy`
How to solve these error??

Adding paranthesis around the print statement should fix the issue.
Python 3 would raise a SyntaxError if we called the print function the Python 2-way without the parentheses.

Python 2.6 -- paramiko import error

I have some scripts that run every 30 minutes in cron that import paramiko. Seemingly at random, I will get one of these two errors during import:
Traceback (most recent call last):
...
File "build/bdist.linux-x86_64/egg/paramiko/__init__.py", line 65, in <module>
File "build/bdist.linux-x86_64/egg/paramiko/transport.py", line 42, in <module>
File "build/bdist.linux-x86_64/egg/paramiko/packet.py", line 39, in <module>
File "build/bdist.linux-x86_64/egg/Crypto/Hash/HMAC.py", line 66, in <module>
File "build/bdist.linux-x86_64/egg/Crypto/Util/strxor.py", line 7, in <module>
File "build/bdist.linux-x86_64/egg/Crypto/Util/strxor.py", line 6, in __bootstrap__
ImportError: dynamic module does not define init function (initstrxor)
-- OR --
Traceback (most recent call last):
...
File "build/bdist.linux-x86_64/egg/paramiko/__init__.py", line 65, in <module>
File "build/bdist.linux-x86_64/egg/paramiko/transport.py", line 53, in <module>
File "build/bdist.linux-x86_64/egg/Crypto/Cipher/ARC4.py", line 66, in <module>
File "build/bdist.linux-x86_64/egg/Crypto/Cipher/_ARC4.py", line 7, in <module>
File "build/bdist.linux-x86_64/egg/Crypto/Cipher/_ARC4.py", line 6, in __bootstrap__
ImportError: dynamic module does not define init function (init_ARC4)
Every time that I have seen this issue, simply rerunning the script allows paramiko to import correctly and the script to finish.
What can cause this issue? Any help is greatly appreciated.

While I have no idea what may be causing the error, it seems it's failing on the native parts of pycrypto, so you may want to retry a couple of times:
from time import sleep
n_tries= 3
import_success= False
while not import_success:
try:
from Crypto.Cipher import Blowfish, AES, DES3, ARC4
from Crypto.Hash import MD5, SHA, SHA256, HMAC
from Crypto import Random
from Crypto.PublicKey import DSA, RSA
from Crypto.Util import Counter, number
import_success= True
except ImportError:
if not n_tries:
raise #re-raise ImportError
n_tries-=1
sleep(1)

Why am I getting an import error upon importing multiprocessing?

I have a script which requires multiprocessing. What I found from this script is that there is a problem with the multiprocessing module. To test this theory, I copied and pasted
from multiprocessing import Process
def f(name):
print('hello', name)
if __name__ == '__main__':
p = Process(target=f, args=('bob',))
p.start()
p.join()
into a test script and received the following traceback
Traceback (most recent call last):
File "a.py", line 1, in <module>
from multiprocessing import Process
File "/usr/lib64/python3.3/multiprocessing/__init__.py", line 40, in <module>
from multiprocessing.util import SUBDEBUG, SUBWARNING
File "/usr/lib64/python3.3/multiprocessing/util.py", line 16, in <module>
import threading # we want threading to install it's
File "/usr/lib64/python3.3/threading.py", line 11, in <module>
from traceback import format_exc as _format_exc
File "/usr/lib64/python3.3/traceback.py", line 3, in <module>
import linecache
File "/usr/lib64/python3.3/linecache.py", line 10, in <module>
import tokenize
File "/usr/lib64/python3.3/tokenize.py", line 30, in <module>
from token import *
File "/home/lucas/Server/ClinApp/weblabs/utils/token.py", line 1, in <module>
from django.conf import settings
File "/usr/lib/python3.3/site-packages/django/conf/__init__.py", line 9, in <module>
import logging
File "/usr/lib64/python3.3/logging/__init__.py", line 195, in <module>
_lock = threading.RLock()
AttributeError: 'module' object has no attribute 'RLock'
Also, I am running fedora 18 64-bit on a quad core ivy bridge. Why am I receiving this traceback error?
Suggestion
Here is what happens when I run RLock
$ python3
>>> import threading
>>> threading.RLock()
<_thread.RLock owner=0 count=0>
>>>

File "/usr/lib64/python3.3/tokenize.py", line 30, in <module>
from token import *
File "/home/lucas/Server/ClinApp/weblabs/utils/token.py", line 1, in <module>
from django.conf import settings
Your /home/lucas/Server/ClinApp/weblabs/utils/token.py script is being imported instead of the standard python 'token.py'. Its got a bug in it or it simply shouldn.t be imported as a top level script. You probably have /home/lucas/Server/ClinApp/weblabs/utils/ in your python path in some way.
Generally, its not a good idea to name python scripts after builtin scripts.

After you rename token.py to something else (get_token.py), remember to delete token.pyc in your local working directory. Or else, you will continue to get the Traceback error message you listed above.

Python Error : cannot import name scanner

System : XP, work with python 2.7
Traceback (most recent call last):
File "<pyshell#2>", line 1, in <module>
import json
File "C:\Python27\ArcGIS10.1\lib\json\__init__.py", line 108, in <module>
from .decoder import JSONDecoder
File "C:\Python27\ArcGIS10.1\lib\json\decoder.py", line 7, in <module>
from json import scanner
ImportError: cannot import name scanner
Anyone can explain me how to manage this error please ???
this morning I haven't got this problem, but this afternoon my script won't work ((

I think this is caused by relative import path,
File "C:\Python27\ArcGIS10.1\lib\json\decoder.py", line 7,
from json import scanner
it's trying to import scanner from
C:\Python27\ArcGIS10.1\lib\json