Python Requests requests.exceptions.SSLError: [Errno 8] _ssl.c:504: EOF occurred in violation of protocol

Question:

I’m on Ubuntu 12.10 with OpenSSL 1.0.1c, python 2.7.3, Requests 1.0.3 and 1.0.4 (tried both), and when attempting to connect to the website in the url variable with the following code.

def SendInitialRequest(xmlmessage, redirecturl):
    url = 'https://centineltest.cardinalcommerce.com/maps/txns.asp'

    payload = 'cmpi_msg=' + ET.tostring(xmlmessage)
    headers = {
        'Content-Type': 'application/x-www-form-urlencoded',
    }
    r = requests.post(url, data=payload, headers=headers, verify=None)
    print r.text

It throws the following error:

Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "clams/libs/centinel/thinclient.py", line 134, in SendInitialRequest
    r = requests.post(url, data=payload, headers=headers, verify=None)
  File "/home/jasonamyers/.virtualenv/clams/lib/python2.7/site-packages/requests/api.py", line 87, in post
    return request('post', url, data=data, **kwargs)
  File "/home/jasonamyers/.virtualenv/clams/lib/python2.7/site-packages/requests/api.py", line 44, in request
    return session.request(method=method, url=url, **kwargs)
  File "/home/jasonamyers/.virtualenv/clams/lib/python2.7/site-packages/requests/sessions.py", line 269, in request
    resp = self.send(prep, stream=stream, timeout=timeout, verify=verify, cert=cert, proxies=proxies)
  File "/home/jasonamyers/.virtualenv/clams/lib/python2.7/site-packages/requests/sessions.py", line 364, in send
    r = adapter.send(request, **kwargs)
  File "/home/jasonamyers/.virtualenv/clams/lib/python2.7/site-packages/requests/adapters.py", line 163, in send
    raise SSLError(e)
requests.exceptions.SSLError: [Errno 8] _ssl.c:504: EOF occurred in violation of protocol

Attempting the connection with openssl returns the following:

$ openssl s_client -connect centineltest.cardinalcommerce.com:443
CONNECTED(00000003)
140019346777760:error:140790E5:SSL routines:SSL23_WRITE:ssl handshake failure:s23_lib.c:177:
---
no peer certificate available
---
No client certificate CA names sent
---
SSL handshake has read 0 bytes and written 226 bytes
---
New, (NONE), Cipher is (NONE)
Secure Renegotiation IS NOT supported
Compression: NONE
Expansion: NONE
---

If I force it to use tls1 it works (output truncated):

$ openssl s_client -tls1 -connect centineltest.cardinalcommerce.com:443
CONNECTED(00000003)
depth=2 C = US, O = "thawte, Inc.", OU = Certification Services Division, OU
verify error_num=20:unable to get local issuer certificate
verify return:0
---

I’ve seen numerous bug reports for this; however, I’ve not found a way to get around it using the python requests library. Any assistance would be greatly appreciated.

Asked By: jasonamyers

||

Answers:

This is a known bug, you can work it around with a hack:

Open up site-packages/requests/packages/urllib3/connectionpool.py (or otherwise just make a local copy of requests inside your own project), and change the block that says:

def connect(self):
    # Add certificate verification
    sock = socket.create_connection((self.host, self.port), self.timeout)

    # Wrap socket using verification with the root certs in
    # trusted_root_certs
    self.sock = ssl_wrap_socket(sock, self.key_file, self.cert_file,
                                cert_reqs=self.cert_reqs,
                                ca_certs=self.ca_certs,
                                server_hostname=self.host,
                                ssl_version=self.ssl_version)

to:

def connect(self):
    # Add certificate verification
    sock = socket.create_connection((self.host, self.port), self.timeout)

    # Wrap socket using verification with the root certs in
    # trusted_root_certs
    self.sock = ssl_wrap_socket(sock, self.key_file, self.cert_file,
                                cert_reqs=self.cert_reqs,
                                ca_certs=self.ca_certs,
                                server_hostname=self.host,
                                ssl_version=ssl.PROTOCOL_TLSv1)

Otherwise, I suppose there’s an override somewhere which is less hacky, but I couldn’t find one with a few glances.

NOTE: On a sidenote, requests from PIP (1.0.4) on a MacOS just works with the URL you provided.

Answered By: favoretti

Reposting this here for others from the requests issue page:

Requests’ does not support doing this before version 1. Subsequent to version 1, you are expected to subclass the HTTPAdapter, like so:

from requests.adapters import HTTPAdapter
from requests.packages.urllib3.poolmanager import PoolManager
import ssl

class MyAdapter(HTTPAdapter):
    def init_poolmanager(self, connections, maxsize, block=False):
        self.poolmanager = PoolManager(num_pools=connections,
                                       maxsize=maxsize,
                                       block=block,
                                       ssl_version=ssl.PROTOCOL_TLSv1)

When you’ve done that, you can do this:

import requests
s = requests.Session()
s.mount('https://', MyAdapter())

Any request through that session object will then use TLSv1.

Answered By: jasonamyers

Unfortunately the accepted answer did not work for me. As a temporary workaround you could also use verify=False when connecting to the secure website.

From Python Requests throwing up SSLError

requests.get('https://example.com', verify=True)
Answered By: Bibek Shrestha

I had the same issue:

raise SSLError(e)
requests.exceptions.SSLError: [Errno 8] _ssl.c:504: EOF occurred in violation of protocol

I had fiddler running, I stopped fiddler capture and did not see this error. Could be because of fiddler.

Answered By: fd98279

I encountered this error, and the fix appears to be turning off SNI, which Python 2.7 does not support:

http://bugs.python.org/issue5639

urllib3 on python 2.7 SNI error on Google App Engine

Answered By: Chris Pushbullet

Setting verify=False only skips verifying the server certificate, but will not help to resolve SSL protocol errors.

This issue is likely due to SSLv2 being disabled on the web server, but Python 2.x tries to establish a connection with PROTOCOL_SSLv23 by default. This happens at https://github.com/python/cpython/blob/360aa60b2a36f5f6e9e20325efd8d472f7559b1e/Lib/ssl.py#L1057

You can monkey-patch ssl.wrap_socket() in the ssl module by overriding the ssl_version keyword parameter. The following code can be used as-is. Put this at the start of your program before making any requests.

import ssl
from functools import wraps
def sslwrap(func):
    @wraps(func)
    def bar(*args, **kw):
        kw['ssl_version'] = ssl.PROTOCOL_TLSv1
        return func(*args, **kw)
    return bar

ssl.wrap_socket = sslwrap(ssl.wrap_socket)
Answered By: chnrxn

Installing the "security" package extras for requests solved for me:

sudo apt-get install libffi-dev
sudo pip install -U requests[security]
Answered By: Ricardo Cabral

I have had this error when connecting to a RabbitMQ MQTT server via TLS. I’m pretty sure the server is broken but anyway it worked with OpenSSL 1.0.1, but not OpenSSL 1.0.2.

You can check your version in Python using this:

import ssl
ssl.OPENSSL_VERSION

I’m not sure how to downgrade OpenSSL within Python (it seems to be statically linked on Windows at least), other than using an older version of Python.

Answered By: Timmmm

To people that can’t get above fixes working.

Had to change file ssl.py to fix it.
Look for function create_default_context and change line:

context = SSLContext(PROTOCOL_SSLv23)

to

context = SSLContext(PROTOCOL_TLSv1)

Maybe someone can create easier solution without editing ssl.py?

Answered By: Zhack

I was having similar issue and I think if we simply ignore the ssl verification will work like charm as it worked for me. So connecting to server with https scheme but directing them not to verify the certificate.

Using requests. Just mention verify=False instead of None

    requests.post(url, data=payload, headers=headers, verify=False)

Hoping this will work for those who needs :).

Answered By: MaNKuR