Python中真正无阻塞的HTTPS服务器

Question

I'm trying to build a truly non-blocking HTTPS server in Python. The following minimal code works just fine if everyone is playing nice:

import BaseHTTPServer
import SimpleHTTPServer
import SocketServer
import ssl 

class ThreadedHTTPServer(SocketServer.ThreadingMixIn, BaseHTTPServer.HTTPServer):
    pass

httpd = ThreadedHTTPServer(('localhost', 4443), SimpleHTTPServer.SimpleHTTPRequestHandler)
httpd.socket = ssl.wrap_socket(httpd.socket, keyfile="localhost.key", certfile="localhost.pem", server_side=True)
httpd.serve_forever()

However, the problem is that this server blocks at least during the TLS handshake.

Test with:

$ nc localhost 4443  # leave this open

And then (in another terminal):

$ wget --no-check-certificate https://localhost:4443/
--2014-10-23 16:55:54--  https://localhost:4443/
Resolving localhost (localhost)... 127.0.0.1
Connecting to localhost (localhost)|127.0.0.1|:4443... connected.

The wget process blocks, indicating that something is blocked in the server. Once I close the nc process, wget continues. This is obviously not practical at all.

How do I get a truly non-blocking HTTPS server in Python, preferably without additional third-party software?

I should mention that the very same code works as expected without TLS (ie, without the wrap_socket line).

---

Steffen Ullrich pointed out how to do it: pass do_handshake_on_connect=False to wrap_socket , then do the handshake yourself. In this case, subclass BaseHTTPServer.HTTPServer , override handle , and then do the handshake as shown in the Python docs (the socket is called self.request ) followed by calling the super method.

Answer 1

You have to do a non-blocking SSL accept by calling ssl.wrap_socket with do_handshake_on_connect=False and later calling do_handshake yourself until it succeeds. See https://docs.python.org/3/library/ssl.html#notes-on-non-blocking-sockets .

You might also simply use Tornado which is a web server written in python and which also does fully non-blocking SSL handling. Even if you don't want to use it yourself you might have a look at the source code to see how this is done (search for do_handshake ).