Develop Reference

Connecting to a Postgres Database over SSL using Sockets in Python

I am trying to connect to a Postgres Database using sockets to enforce a particular TLS version from the client in order to verify that the Database does not accept connections from the client which uses an older version of TLS like tlsv1.1. The connection is failing on handshake with the following error :
python test2.py
Traceback (most recent call last): File "test2.py", line 12, in
ssl_version=ssl.PROTOCOL_TLSv1_2) File "<>/python3.6/lib/python3.6/ssl.py", line 1232, in
get_server_certificate
with context.wrap_socket(sock) as sslsock: File "<>/python3.6/lib/python3.6/ssl.py", line 407, in wrap_socket
_context=self, _session=session) File "<>/python3.6/lib/python3.6/ssl.py", line 817, in init
self.do_handshake() File "<>/python3.6/lib/python3.6/ssl.py", line 1077, in do_handshake
self._sslobj.do_handshake() File "<>/python3.6/lib/python3.6/ssl.py", line 689, in do_handshake
self._sslobj.do_handshake() ssl.SSLEOFError: EOF occurred in violation of protocol (_ssl.c:852)
The following is a snippet of the code:
import socket
import ssl
hostname = <DB_Endpoint>
context = ssl.create_default_context()
with socket.create_connection((hostname, 8200)) as sock:
with context.wrap_socket(sock, server_hostname=hostname) as ssock:
print(ssock.version())

How to make https server on sockets

I am trying to make a web server on sockets in python. I saw how to make https support for server from module http.server in python by wrapping its socket with a .pem certificate. I would like to make https support on my socket server. I have a self-signed certificate for a localhost and it worked for a ready-made server, but my server has an error:
Traceback(most recent call last):
File "webserver.py", line 84, in main
server.start_server()
File "C:\b\nw\12t\http_lite.py", line 103, in start_server
conn, addr = ssock.accept()
File "C:\Python37\lib\ssl.py", line 1188, in accept
server_side=True)
File "C:\Python37\lib\ssl.py", line 423, in wrap_socket
session = session
File "C:\Python37\lib\ssl.py", line 870, in _create
self.do_handshake()
File "C:\Python37\lib\ssl.py", line 1139, in do_handshake
self._sslobj.do_handshake()
ssl.SSLError: [SSL: SSLV3_ALERT_CERTIFICATE_UNKNOWN] sslv3 alert certificate unknown (_ssl.c: 1076)
And also if I allow to open a site in a browser:
Traceback (most recent call last):
File "webserver.py", line 84, in main
server.start_server()
File "C:\b\nw\12t\http_lite.py", line 100, in start_server
conn, addr = ssock.accept()
File "C:\Python37\lib\ssl.py", line 1188, in accept
server_side=True)
File "C:\Python37\lib\ssl.py", line 423, in wrap_socket
session = session
File "C:\Python37\lib\ssl.py", line 870, in _create
self.do_handshake()
File "C:\Python37\lib\ssl.py", line 1139, in do_handshake
self._sslobj.do_handshake()
OSError: [Errno 0] Error
My connection setup code looks like this:
s = socket.socket(socket.AF_INET, socket.SOCK_STREAM, proto=0)
s.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
s.bind ((self.host, self.port))
s.listen(self.backlog)
ssock = ssl.wrap_socket(s,
server_side=True,
certfile='localhost.pem',
ssl_version=ssl.PROTOCOL_TLSv1)
in the while loop
conn, addr = ssock.accept()
....
Please help me figure out what I am doing wrong.
Sorry for my bad English.

kafka-python SASL/SCRAM-SHA-256 auth

I need to connect to Kafka broker in python using SASL/SCRAM-SHA-256 authentication.
I use the kafka-python (2.0.1) python library which allows this kind of connection/authentication.
This is an example of code, but i get the error ... not Brokers available
prod = KafkaProducer(bootstrap_servers='server:9093',
security_protocol='SASL_SSL',
ssl_certfile='path to ca in pem format',
sasl_mechanism='SCRAM-SHA-256',
sasl_plain_username='xxx',
sasl_plain_password='xxx')
Getting the following error
ssl.SSLError: [SSL: CERTIFICATE_VERIFY_FAILED] certificate verify failed (_ssl.c:897)
20-04-06 09:58:52 - root - 1 - 140658864072256 - MainThread - ERROR - Error in connection to kafka
Traceback (most recent call last):
File "/*****/*****/dao/kafka_dao.py", line 44, in __init__
**self.consumer_additional_params)
File "/opt/app-root/lib/python3.6/site-packages/kafka/consumer/group.py", line 355, in __init__
self._client = KafkaClient(metrics=self._metrics, **self.config)
File "/opt/app-root/lib/python3.6/site-packages/kafka/client_async.py", line 242, in __init__
self.config['api_version'] = self.check_version(timeout=check_timeout)
File "/opt/app-root/lib/python3.6/site-packages/kafka/client_async.py", line 907, in check_version
version = conn.check_version(timeout=remaining, strict=strict, topics=list(self.config['bootstrap_topics_filter']))
File "/opt/app-root/lib/python3.6/site-packages/kafka/conn.py", line 1228, in check_version
if not self.connect_blocking(timeout_at - time.time()):
File "/opt/app-root/lib/python3.6/site-packages/kafka/conn.py", line 337, in connect_blocking
self.connect()
File "/opt/app-root/lib/python3.6/site-packages/kafka/conn.py", line 426, in connect
if self._try_handshake():
File "/opt/app-root/lib/python3.6/site-packages/kafka/conn.py", line 505, in _try_handshake
self._sock.do_handshake()
File "/usr/lib64/python3.6/ssl.py", line 1033, in do_handshake
self._sslobj.do_handshake()
File "/usr/lib64/python3.6/ssl.py", line 645, in do_handshake
self._sslobj.do_handshake()
Where am I doing wrong??

Python connecting to FTPS server filezilla violation of protocol error

Question I want to be able to connect to and download a file from my remote FTP filezilla. I am able to connect however as soon as it executes "ftp.retrlines('LIST')" I get an error as described below. Any help would be greatly appreciated!!!
Here is my script
from ftplib import FTP_TLS
ftp = FTP_TLS('111.111.111.111) # Hidden IP for my FTP SERVER
ftp.login('ftpuser', 'ftppassword12345')
ftp.prot_p() # securing data connection explicitly
ftp.cwd('/') # change working directory to the root
ftp.retrlines('LIST') # This is where it fails
Here is the error
Traceback (most recent call last):
File "ftps_.py", line 7, in <module>
ftp.retrlines('LIST')
File "/usr/local/Cellar/python/2.7.11/Frameworks/Python.framework/Versions/2.7/lib/python2.7/ftplib.py", line 735, in retrlines
conn = self.transfercmd(cmd)
File "/usr/local/Cellar/python/2.7.11/Frameworks/Python.framework/Versions/2.7/lib/python2.7/ftplib.py", line 376, in transfercmd
return self.ntransfercmd(cmd, rest)[0]
File "/usr/local/Cellar/python/2.7.11/Frameworks/Python.framework/Versions/2.7/lib/python2.7/ftplib.py", line 713, in ntransfercmd
server_hostname=self.host)
File "/usr/local/Cellar/python/2.7.11/Frameworks/Python.framework/Versions/2.7/lib/python2.7/ssl.py", line 352, in wrap_socket
_context=self)
File "/usr/local/Cellar/python/2.7.11/Frameworks/Python.framework/Versions/2.7/lib/python2.7/ssl.py", line 579, in __init__
self.do_handshake()
File "/usr/local/Cellar/python/2.7.11/Frameworks/Python.framework/Versions/2.7/lib/python2.7/ssl.py", line 808, in do_handshake
self._sslobj.do_handshake()
ssl.SSLEOFError: EOF occurred in violation of protocol (_ssl.c:590)

Socket error using the validate_email 1.1 package

I trying to get validate_email package (https://pypi.python.org/pypi/validate_email) to verify an email for me on a Windows 7/Python 2.7 device. The following works:
>>> validate_email('example#example.com')
True
>>> validate_email('example#example.com',check_mx=True)
True
>>> validate_email('example#example.com',verify=True)
True
But when I try a commercial email server example to check if the host has SMPT Server and/or the email really exists, it fails as follows:
>>> validate_email('example#gmail.com')
True
>>> validate_email('example#gmail.com',check_mx=True)
Traceback (most recent call last):
File "<interactive input>", line 1, in <module>
File "C:\Python27\lib\site-packages\validate_email.py", line 104, in validate_email
smtp.connect(mx[1])
File "C:\Python27\lib\smtplib.py", line 309, in connect
self.sock = self._get_socket(host, port, self.timeout)
File "C:\Python27\lib\smtplib.py", line 284, in _get_socket
return socket.create_connection((port, host), timeout)
File "C:\Python27\lib\socket.py", line 571, in create_connection
raise err
error: [Errno 10013] An attempt was made to access a socket in a way forbidden by its access permissions
>>> validate_email('example#gmail.com',verify=True)
Traceback (most recent call last):
File "<interactive input>", line 1, in <module>
File "C:\Python27\lib\site-packages\validate_email.py", line 104, in validate_email
smtp.connect(mx[1])
File "C:\Python27\lib\smtplib.py", line 309, in connect
self.sock = self._get_socket(host, port, self.timeout)
File "C:\Python27\lib\smtplib.py", line 284, in _get_socket
return socket.create_connection((port, host), timeout)
File "C:\Python27\lib\socket.py", line 571, in create_connection
raise err
error: [Errno 10013] An attempt was made to access a socket in a way forbidden by its access permissions
It appears that I'm trying to access a port that I don't have permission to, but I don't know how to change to a port that would work and has the correct permissions.
Any suggestions?

It looks like this could be a problem with Windows Firewall blocking access to certain ports.
https://stackoverflow.com/a/15628078/1308566