Using SSL With Eventlet

Eventlet makes it easy to use non-blocking SSL sockets. If you’re using Python 2.6 or later, you’re all set, eventlet wraps the built-in ssl module. If on Python 2.5 or 2.4, you have to install pyOpenSSL to use eventlet.

In either case, the green modules handle SSL sockets transparently, just like their standard counterparts. As an example, can be used to fetch https urls in as non-blocking a fashion as you please:

from import urllib2
from eventlet import spawn
bodies = [spawn(urllib2.urlopen, url)
     for url in ("","")]
for b in bodies:

With Python 2.6

To use ssl sockets directly in Python 2.6, use, which is a non-blocking wrapper around the standard Python ssl module, and which has the same interface. See the standard documentation for instructions on use.

With Python 2.5 or Earlier

Prior to Python 2.6, there is no ssl, so SSL support is much weaker. Eventlet relies on pyOpenSSL to implement its SSL support on these older versions, so be sure to install pyOpenSSL, or you’ll get an ImportError whenever your system tries to make an SSL connection.

Once pyOpenSSL is installed, you can then use the modules, like to fetch https urls. You can also use, which is a nonblocking wrapper for socket.ssl().

PyOpenSSL has exactly the same interface as pyOpenSSL (docs), and works in all versions of Python. This module is much more powerful than socket.ssl(), and may have some advantages over ssl, depending on your needs.

Here’s an example of a server:

from import socket
from import SSL

# insecure context, only for example purposes
context = SSL.Context(SSL.SSLv23_METHOD)
context.set_verify(SSL.VERIFY_NONE, lambda *x: True))

# create underlying green socket and wrap it in ssl
sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
connection = SSL.Connection(context, sock)

# configure as server
connection.bind(('', 80443))

# accept one client connection then close up shop
client_conn, addr = connection.accept()