# python – urllib and “SSL: CERTIFICATE_VERIFY_FAILED” Error

## The Question :

311 people think this question is useful

I am getting the following error:

Exception in thread Thread-3:
Traceback (most recent call last):
File "/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/threading.py", line 810, in        __bootstrap_inner
self.run()
File "/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/threading.py", line 763, in  run
self.__target(*self.__args, **self.__kwargs)
File "/Users/Matthew/Desktop/Skypebot 2.0/bot.py", line 271, in process
File "/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/urllib2.py", line 154, in urlopen
return opener.open(url, data, timeout)
File "/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/urllib2.py", line 431, in open
response = self._open(req, data)
File "/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/urllib2.py", line 449, in _open
'_open', req)
File "/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/urllib2.py", line 409, in _call_chain
result = func(*args)
File "/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/urllib2.py", line 1240, in https_open
context=self._context)
File "/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/urllib2.py", line 1197, in do_open
raise URLError(err)
URLError: <urlopen error [SSL: CERTIFICATE_VERIFY_FAILED] certificate verify failed (_ssl.c:581)>



This is the code that is causing this error:

if input.startswith("!web"):
input = input.replace("!web ", "")
url = "https://domainsearch.p.mashape.com/index.php?name=" + input
req = urllib2.Request(url, headers={ 'X-Mashape-Key': 'XXXXXXXXXXXXXXXXXXXX' })
Message.Chat.SendMessage ("" + info)



The API I’m using requires me to use HTTPS. How can I make it bypass the verification?

• There is nothing wrong with the URL and it can be successfully verified with the common trusted certificates. So you should better not try to bypass certificate validation, but to fix it. Which version of python you are using?
• This might be related to stackoverflow.com/a/27826829/3081018. The server uses the same kind of certificate chain with multiple trust path. See there which cafile you might need to use for verification.
• This error also occurs on Python 3.5 after upgrading to yosemite
• This explains the situation. access.redhat.com/articles/2039753
• “How can I make it bypass the verification?” is the wrong question. You should probably ask how to validate the certificate provided by the domain.

324 people think this answer is useful

If you just want to bypass verification, you can create a new SSLContext. By default newly created contexts use CERT_NONE.

Be careful with this as stated in section 17.3.7.2.1

When calling the SSLContext constructor directly, CERT_NONE is the default. Since it does not authenticate the other peer, it can be insecure, especially in client mode where most of time you would like to ensure the authenticity of the server you’re talking to. Therefore, when in client mode, it is highly recommended to use CERT_REQUIRED.

But if you just want it to work now for some other reason you can do the following, you’ll have to import ssl as well:

input = input.replace("!web ", "")
url = "https://domainsearch.p.mashape.com/index.php?name=" + input
req = urllib2.Request(url, headers={ 'X-Mashape-Key': 'XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX' })
gcontext = ssl.SSLContext()  # Only for gangstars
Message.Chat.SendMessage ("" + info)



This should get round your problem but you’re not really solving any of the issues, but you won’t see the [SSL: CERTIFICATE_VERIFY_FAILED] because you now aren’t verifying the cert!

To add to the above, if you want to know more about why you are seeing these issues you will want to have a look at PEP 476.

This PEP proposes to enable verification of X509 certificate signatures, as well as hostname verification for Python’s HTTP clients by default, subject to opt-out on a per-call basis. This change would be applied to Python 2.7, Python 3.4, and Python 3.5.

There is an advised opt out which isn’t dissimilar to my advice above:

import ssl

# This restores the same behavior as before.
context = ssl._create_unverified_context()
urllib.urlopen("https://no-valid-cert", context=context)



It also features a highly discouraged option via monkeypatching which you don’t often see in python:

import ssl

ssl._create_default_https_context = ssl._create_unverified_context



Which overrides the default function for context creation with the function to create an unverified context.

Please note with this as stated in the PEP:

This guidance is aimed primarily at system administrators that wish to adopt newer versions of Python that implement this PEP in legacy environments that do not yet support certificate verification on HTTPS connections. For example, an administrator may opt out by adding the monkeypatch above to sitecustomize.py in their Standard Operating Environment for Python. Applications and libraries SHOULD NOT be making this change process wide (except perhaps in response to a system administrator controlled configuration setting).

If you want to read a paper on why not validating certs is bad in software you can find it here!

418 people think this answer is useful

This isn’t a solution to your specific problem, but I’m putting it here because this thread is the top Google result for “SSL: CERTIFICATE_VERIFY_FAILED”, and it lead me on a wild goose chase.

If you have installed Python 3.6 on OSX and are getting the “SSL: CERTIFICATE_VERIFY_FAILED” error when trying to connect to an https:// site, it’s probably because Python 3.6 on OSX has no certificates at all, and can’t validate any SSL connections. This is a change for 3.6 on OSX, and requires a post-install step, which installs the certifi package of certificates. This is documented in the ReadMe, which you should find at /Applications/Python\ 3.6/ReadMe.rtf

The ReadMe will have you run this post-install script, which just installs certifi: /Applications/Python\ 3.6/Install\ Certificates.command

76 people think this answer is useful

To expand on Craig Glennie’s answer:

in Python 3.6.1 on MacOs Sierra

Entering this in the bash terminal solved the problem:

pip install certifi
/Applications/Python\ 3.6/Install\ Certificates.command



49 people think this answer is useful

On Windows, Python does not look at the system certificate, it uses its own located at ?\lib\site-packages\certifi\cacert.pem.

2. open the file in editor and copy it’s content to clipboard
3. find your cacert.pem location: from requests.utils import DEFAULT_CA_BUNDLE_PATH; print(DEFAULT_CA_BUNDLE_PATH)
4. edit the cacert.pem file and paste your domain validation certificate at the end of the file.
5. Save the file and enjoy requests!

44 people think this answer is useful

My solution for Mac OS X:

I’ve found that this installer is taking care of updating the links and symlinks for the new Python a lot better than homebrew.

2) Install a new certificate using “./Install Certificates.command” which is in the refreshed Python 3.6 directory

> cd "/Applications/Python 3.6/"
> sudo "./Install Certificates.command"



38 people think this answer is useful

I was having a similar problem, though I was using urllib.request.urlopen in Python 3.4, 3.5, and 3.6. (This is a portion of the Python 3 equivalent of urllib2, per the note at the head of Python 2’s urllib2 documentation page.)

My solution was to pip install certifi to install certifi, which has:

… a carefully curated collection of Root Certificates for validating the trustworthiness of SSL certificates while verifying the identity of TLS hosts.

Then, in my code where I previously just had:

import urllib.request as urlrq

resp = urlrq.urlopen('https://example.com/bar/baz.html')



I revised it to:

import urllib.request as urlrq
import certifi

resp = urlrq.urlopen('https://example.com/bar/baz.html', cafile=certifi.where())



If I read the urllib2.urlopen documentation correctly, it also has a cafile argument. So, urllib2.urlopen([...], certifi.where()) might work for Python 2.7 as well.

UPDATE (2020-01-01): As of Python 3.6, the cafile argument to urlopen has been deprecated, with the context argument supposed to be specified instead. I found the following to work equally well on 3.5 through 3.8:

import urllib.request as urlrq
import certifi
import ssl

resp = urlrq.urlopen('https://example.com/bar/baz.html', context=ssl.create_default_context(cafile=certifi.where()))



33 people think this answer is useful

PYTHONHTTPSVERIFY=0



Note that this will disable all HTTP verification so is a bit of a sledgehammer approach, however if verification isn’t required it may be an effective solution.

13 people think this answer is useful
import requests
requests.packages.urllib3.disable_warnings()

import ssl

try:
_create_unverified_https_context = ssl._create_unverified_context
except AttributeError:
# Legacy Python that doesn't verify HTTPS certificates by default
pass
else:
# Handle target environment that doesn't support HTTPS verification
ssl._create_default_https_context = _create_unverified_https_context



Taken from here https://gist.github.com/michaelrice/a6794a017e349fc65d01

9 people think this answer is useful

Like I’ve written in a comment, this problem is probably related to this SO answer.

In short: there are multiple ways to verify the certificate. The verification used by OpenSSL is incompatible with the trusted root certificates you have on your system. OpenSSL is used by Python.

You could try to get the missing certificate for Verisign Class 3 Public Primary Certification Authority and then use the cafile option according to the Python documentation:

urllib2.urlopen(req, cafile="verisign.pem")



9 people think this answer is useful

I had a similar problem on one of my Linux machines. Generating fresh certificates and exporting an environment variable pointing to the certificates directory fixed it for me:

$sudo update-ca-certificates --fresh$ export SSL_CERT_DIR=/etc/ssl/certs



7 people think this answer is useful

I need to add another answer because just like Craig Glennie, I went on a wild goose chase due to the many posts referring to this problem across the Web.

I am using MacPorts, and what I originally thought was a Python problem was in fact a MacPorts problem: it does not install a root certificate with its installation of openssl. The solution is to port install curl-ca-bundle, as mentioned in this blog post.

6 people think this answer is useful

# Solution for Anaconda

My setup is Anaconda Python 3.7 on MacOS with a proxy. The paths are different.

• This is how you get the correct certificates path:
import ssl
ssl.get_default_verify_paths()



which on my system produced

Out[35]: DefaultVerifyPaths(cafile='/miniconda3/ssl/cert.pem', capath=None,
openssl_cafile_env='SSL_CERT_FILE', openssl_cafile='/miniconda3/ssl/cert.pem',
openssl_capath_env='SSL_CERT_DIR', openssl_capath='/miniconda3/ssl/certs')



Once you know where the certificate goes, then you concatenate the certificate used by the proxy to the end of that file.

I had already set up conda to work with my proxy, by running:

conda config --set ssl_verify <pathToYourFile>.crt



If you don’t remember where your cert is, you can find it in ~/.condarc:

ssl_verify: <pathToYourFile>.crt



Now concatenate that file to the end of /miniconda3/ssl/cert.pem and requests should work, and in particular sklearn.datasets and similar tools should work.

# Further Caveats

The other solutions did not work because the Anaconda setup is slightly different:

• The path Applications/Python\ 3.X simply doesn’t exist.

• The path provided by the commands below is the WRONG path

from requests.utils import DEFAULT_CA_BUNDLE_PATH
DEFAULT_CA_BUNDLE_PATH



6 people think this answer is useful
$cd$HOME
$wget --quiet https://curl.haxx.se/ca/cacert.pem$ export SSL_CERT_FILE=\$HOME/cacert.pem



4 people think this answer is useful

Python 2.7.12 (default, Jul 29 2016, 15:26:22) fixed the mentioned issue. This information might help someone else.

4 people think this answer is useful

For Python 3.4+ on Centos 6/7,Fedora, just install the trusted CA this way :

1. Copy the CA.crt to /etc/pki/ca-trust/source/anchors/
2. update-ca-trust force-enable
3. update-ca-trust extract

4 people think this answer is useful

I am surprised all these instruction didn’t solved my problem. Nonetheless, the diagnostic is correct (BTW, I am using Mac and Python3.6.1). So, to summarize the correct part :

• On Mac, Apple is dropping OpenSSL
• Python now uses it own set of CA Root Certificate
• Binary Python installation provided a script to install the CA Root certificate Python needs (“/Applications/Python 3.6/Install Certificates.command”)

For me, the script doesn’t work, and all those certifi and openssl installation failed to fix too. Maybe because I have multiple python 2 and 3 installations, as well as many virtualenv. At the end, I need to fix it by hand.

pip install certifi   # for your virtualenv
mkdir -p /Library/Frameworks/Python.framework/Versions/3.6/etc/openssl
/Library/Frameworks/Python.framework/Versions/3.6/etc/openssl/cert.pem



If that still fails you. Then re/install OpenSSL as well.

port install openssl



4 people think this answer is useful

I have found this over here

I found this solution, insert this code at the beginning of your source file:

import ssl

try:
_create_unverified_https_context = ssl._create_unverified_context
except AttributeError:
# Legacy Python that doesn't verify HTTPS certificates by default
pass
else:
# Handle target environment that doesn't support HTTPS verification
ssl._create_default_https_context = _create_unverified_https_context



This code makes the verification undone so that the ssl certification is not verified.

3 people think this answer is useful

I hang my head in semi-shame, as I had the same issue, except that in my case, the URL I was hitting was valid, the certificate was valid. What wasn’t valid was my connection out to the web. I had failed to add proxy details into the browser (IE in this case). This stopped the verification process from happening correctly.
Added in the proxy details and my python was then very happy .

2 people think this answer is useful

Like you, I am using python 2.7 on my old iMac (OS X 10.6.8), I met the problem too, using urllib2.urlopen :

urlopen error [SSL: CERTIFICATE_VERIFY_FAILED]



My programs were running fine without SSL certificate problems and suddently (after dowloading programs), they crashed with this SSL error.

The problem was the version of python used :

2. problem with the one instaled by Homebrew tool : “brew install python”, version located in /usr/local/bin.

A chapter, called Certificate verification and OpenSSL [CHANGED for Python 2.7.9], in /Applications/Python 2.7/ReadMe.rtf explains the problem with many details.

2 people think this answer is useful

Python 2.7 on Amazon EC2 with centOS 7

I had to set the env variable SSL_CERT_DIR to point to my ca-bundle which was located at /etc/ssl/certs/ca-bundle.crt

2 people think this answer is useful

The SSL: CERTIFICATE_VERIFY_FAILED error could also occur because an Intermediate Certificate is missing in the ca-certificates package on Linux. For example, in my case the intermediate certificate “DigiCert SHA2 Secure Server CA” was missing in the ca-certificates package even though the Firefox browser includes it. You can find out which certificate is missing by directly running the wget command on the URL causing this error. Then you can search for the corresponding link to the CRT file for this certificate from the official website (e.g. https://www.digicert.com/digicert-root-certificates.htm in my case) of the Certificate Authority. Now, to include the certificate that is missing in your case, you may run the below commands using your CRT file download link instead:

wget https://cacerts.digicert.com/DigiCertSHA2SecureServerCA.crt

mv DigiCertSHA2SecureServerCA.crt DigiCertSHA2SecureServerCA.der

openssl x509 -inform DER -outform PEM -in DigiCertSHA2SecureServerCA.der -out DigicertSHA2SecureServerCA.pem.crt

sudo mkdir /usr/share/ca-certificates/extra

sudo cp DigicertSHA2SecureServerCA.pem.crt /usr/share/ca-certificates/extra/

sudo dpkg-reconfigure ca-certificates



After this you may test again with wget for your URL as well as by using the python urllib package. For more details, refer to: https://bugs.launchpad.net/ubuntu/+source/ca-certificates/+bug/1795242

1 people think this answer is useful

Try

pip install –trusted-host pypi.python.org packagename

It worked for me.

1 people think this answer is useful

Take a look at

/Applications/Python 3.6/Install Certificates.command

You can also go to Aplications ans click on Certificates.command

1 people think this answer is useful

In my case I was getting this error because requests and urllib3 versions were incompatible, giving the following error during installation:

ERROR: requests 2.21.0 has requirement urllib3<1.25,>=1.21.1, but you'll have urllib3 1.25 which is incompatible.


pip install 'urllib3<1.25' --force-reinstall



did the trick.

1 people think this answer is useful

Another Anaconda solution. I was getting CERTIFICATE_VERIFY_FAILED in my Python 2.7 environment on macOS. It turns out the conda paths were bad:

base (3.7) environment:

>>> import ssl
>>> ssl.get_default_verify_paths()
DefaultVerifyPaths(cafile='/usr/local/anaconda3/ssl/cert.pem', capath=None, openssl_cafile_env='SSL_CERT_FILE', openssl_cafile='/usr/local/anaconda3/ssl/cert.pem', openssl_capath_env='SSL_CERT_DIR', openssl_capath='/usr/local/anaconda3/ssl/certs')



2.7 environment (paths did not exist!):

DefaultVerifyPaths(cafile='', capath=None, openssl_cafile_env='SSL_CERT_FILE', openssl_cafile='/usr/local/anaconda3/envs/py27/ssl/cert.pem', openssl_capath_env='SSL_CERT_DIR', openssl_capath='/usr/local/anaconda3/envs/py27/ssl/certs')



The fix:

cd /usr/local/anaconda3/envs/py27/
mkdir ssl
cd ssl
ln -s ../../../ssl/cert.pem



1 people think this answer is useful

There are cases when you can not use insecure connections or pass ssl context into urllib request. Here my solution based on https://stackoverflow.com/a/28052583/6709778

In a case if you want use your own cert file

import ssl

def new_ssl_context_decorator(*args, **kwargs):
kwargs['cafile'] = '/etc/ssl/certs/ca-certificates.crt'
return ssl.create_default_context(*args, **kwargs)

ssl._create_default_https_context = ssl._create_unverified_context



or you can use shared file from certifi

def new_ssl_context_decorator(*args, **kwargs):
import certifi
kwargs['cafile'] = certifi.where()
return ssl.create_default_context(*args, **kwargs)



0 people think this answer is useful

2. Navigate to https://

On Fedora

1. unzip and change the extension from .0 to .cer
2. Copy it to the /etc/pki/ca-trust/source/anchors/
3. run the update-ca-trust command.

0 people think this answer is useful

# installing steps for nltk (I had python3 (3.6.2) installed already in MAC OS X

sudo easy_install pip



use ignore installed option to ignore uninstalling previous version of six, else, it gives an error while uninstalling and does not movie forward

sudo pip3 install -U nltk --ignore-installed six



Check the installation of pip and python, use the ‘3’ versions

which python python2 python3
which pip pip2 pip3



Check if NLTK is installed

python3
import nltk
nltk.__path__
['/Library/Frameworks/Python.framework/Versions/3.6/lib/python3.6/site-packages/nltk']



Install SSL certificate prior to installing the examples book, else we will certificate error while installing the examples

/Applications/Python\ 3.6/Install\ Certificates.command



That completed the installation successfully of nltk and nltk_ata for book examples

0 people think this answer is useful

Installing PyOpenSSL using pip worked for me (without converting to PEM):

pip install PyOpenSSL