.. _security: Security: Verified HTTPS with SSL/TLS ===================================== Very important fact: **By default, urllib3 does not verify HTTPS requests.** The historic reason for this is that we rely on ``httplib`` for some of the HTTP protocol implementation, and ``httplib`` does not verify requests out of the box. This is not a good reason, but here we are. Luckily, it's not too hard to enable verified HTTPS requests and there are a few ways to do it. Python with SSL enabled ----------------------- First we need to make sure your Python installation has SSL enabled. Easiest way to check is to simply open a Python shell and type `import ssl`:: >>> import ssl Traceback (most recent call last): ... ImportError: No module named _ssl If you got an ``ImportError``, then your Python is not compiled with SSL support and you'll need to re-install it. Read `this StackOverflow thread `_ for details. Otherwise, if ``ssl`` imported cleanly, then we're ready to setup our certificates: :ref:`certifi-with-urllib3`. Enabling SSL on Google AppEngine ++++++++++++++++++++++++++++++++ If you're using Google App Engine, you'll need to add ``ssl`` as a library dependency to your yaml file, like this:: libraries: - name: ssl version: latest If it's still not working, you may need to enable billing on your account to `enable using sockets `_. .. _certifi-with-urllib3: Using Certifi with urllib3 -------------------------- `Certifi `_ is a package which ships with Mozilla's root certificates for easy programmatic access. 1. Install the Python ``certifi`` package:: $ pip install certifi 2. Setup your pool to require a certificate and provide the certifi bundle:: import urllib3 import certifi http = urllib3.PoolManager( cert_reqs='CERT_REQUIRED', # Force certificate check. ca_certs=certifi.where(), # Path to the Certifi bundle. ) # You're ready to make verified HTTPS requests. try: r = http.request('GET', 'https://example.com/') except urllib3.exceptions.SSLError as e: # Handle incorrect certificate error. ... Make sure to update your ``certifi`` package regularly to get the latest root certificates. Using your system's root certificates ------------------------------------- Your system's root certificates may be more up-to-date than maintaining your own, but the trick is finding where they live. Different operating systems have them in different places. For example, on most Linux distributions they're at ``/etc/ssl/certs/ca-certificates.crt``. On Windows and OS X? `It's not so simple `_. Once you find your root certificate file:: import urllib3 ca_certs = "/etc/ssl/certs/ca-certificates.crt" # Or wherever it lives. http = urllib3.PoolManager( cert_reqs='CERT_REQUIRED', # Force certificate check. ca_certs=ca_certs, # Path to your certificate bundle. ) # You're ready to make verified HTTPS requests. try: r = http.request('GET', 'https://example.com/') except urllib3.exceptions.SSLError as e: # Handle incorrect certificate error. ... .. _pyopenssl: OpenSSL / PyOpenSSL ------------------- By default, we use the standard library's ``ssl`` module. Unfortunately, there are several limitations which are addressed by PyOpenSSL: - (Python 2.x) SNI support. - (Python 2.x-3.2) Disabling compression to mitigate `CRIME attack `_. To use the Python OpenSSL bindings instead, you'll need to install the required packages:: $ pip install pyopenssl ndg-httpsclient pyasn1 If ``cryptography`` fails to install as a dependency, make sure you have `libffi `_ available on your system and run ``pip install cryptography``. Once the packages are installed, you can tell urllib3 to switch the ssl backend to PyOpenSSL with :func:`~urllib3.contrib.pyopenssl.inject_into_urllib3`:: import urllib3.contrib.pyopenssl urllib3.contrib.pyopenssl.inject_into_urllib3() Now you can continue using urllib3 as you normally would. For more details, check the :mod:`~urllib3.contrib.pyopenssl` module. Installing urllib3 with SNI support and certificates ---------------------------------------------------- By default, if you need to use SNI on Python 2.6 or Python 2.7.0-2.7.8, you have to install PyOpenSSL, ndghttpsclient, and pyasn1 separately. Further, to use certifi you have to install it separately. If you know that you want these dependencies when you install urllib3, you can now do:: pip install urllib3[secure] This will install the SNI dependencies on Python 2.6 and 2.7 (we cannot yet restrict the microversion for 2.7) and certifi on all versions of Python. .. note:: If you do this on linux, e.g., Ubuntu 14.04, you will need extra system dependencies for PyOpenSSL. Specifically, PyOpenSSL requires cryptography which will require you to install: - build-essential - python-dev - libffi-dev - libssl-dev The package names may vary depending on the distribution of linux you are using. .. _insecurerequestwarning: InsecureRequestWarning ---------------------- .. versionadded:: 1.9 Unverified HTTPS requests will trigger a warning via Python's ``warnings`` module:: urllib3/connectionpool.py:736: InsecureRequestWarning: Unverified HTTPS request is being made. Adding certificate verification is strongly advised. See: https://urllib3.readthedocs.org/en/latest/security.html This would be a great time to enable HTTPS verification: :ref:`certifi-with-urllib3`. For info about disabling warnings, see `Disabling Warnings`_. InsecurePlatformWarning ----------------------- .. versionadded:: 1.11 Certain Python platforms (specifically, versions of Python earlier than 2.7.9) have restrictions in their ``ssl`` module that limit the configuration that ``urllib3`` can apply. In particular, this can cause HTTPS requests that would succeed on more featureful platforms to fail, and can cause certain security features to be unavailable. If you encounter this warning, it is strongly recommended you upgrade to a newer Python version, or that you use pyOpenSSL as described in the :ref:`pyopenssl` section. For info about disabling warnings, see `Disabling Warnings`_. SNIMissingWarning ----------------- .. versionadded:: 1.13 Certain Python distributions (specifically, versions of Python earlier than 2.7.9) and older OpenSSLs have restrictions that prevent them from using the SNI (Server Name Indication) extension. This can cause unexpected behaviour when making some HTTPS requests, usually causing the server to present the a TLS certificate that is not valid for the website you're trying to access. If you encounter this warning, it is strongly recommended that you upgrade to a newer Python version, or that you use pyOpenSSL as described in the :ref:`pyopenssl` section. For info about disabling warnings, see `Disabling Warnings`_. Disabling Warnings ------------------ Making unverified HTTPS requests is strongly discouraged. ˙ ͜ʟ˙ But if you understand the ramifications and still want to do it... Within the code +++++++++++++++ If you know what you're doing and would like to disable all ``urllib3`` warnings, you can use :func:`~urllib3.disable_warnings`:: import urllib3 urllib3.disable_warnings() Alternatively, if you are using Python's ``logging`` module, you can capture the warnings to your own log:: logging.captureWarnings(True) Capturing the warnings to your own log is much preferred over simply disabling the warnings. Without modifying code ++++++++++++++++++++++ If you are using a program that uses ``urllib3`` and don't want to change the code, you can suppress warnings by setting the ``PYTHONWARNINGS`` environment variable in Python 2.7+ or by using the ``-W`` flag with the Python interpreter (see `docs `_), such as:: PYTHONWARNINGS="ignore:Unverified HTTPS request" ./do-insecure-request.py