SimpleAuthServer: A IPv6 Python 3 SimpleHTTPServer with authentication

SimpleAuthServer.py

import base64
from http.server import HTTPServer
from http.server import SimpleHTTPRequestHandler
import socket

key = base64.b64encode(b"user:password")

class HTTPServerV6(HTTPServer):
    address_family = socket.AF_INET6


class AuthHandler(SimpleHTTPRequestHandler):
    ''' Main class to present webpages and authentication. '''
    def do_HEAD(self):
        print("send header")
        self.send_response(200)
        self.send_header('Content-type', 'text/html')
        self.end_headers()

    def do_AUTHHEAD(self):
        print("send header")
        self.send_response(401)
        self.send_header('WWW-Authenticate', 'Basic realm=\"Test\"')
        self.send_header('Content-type', 'text/html')
        self.end_headers()

    def do_GET(self):
        global key
        ''' Present frontpage with user authentication. '''
        if self.headers.get('Authorization') == None:
            self.do_AUTHHEAD()
            self.wfile.write('no auth header received')
        elif self.headers.get('Authorization') == 'Basic '+key.decode():
            super().do_GET()
        else:
            self.do_AUTHHEAD()
            self.wfile.write(self.headers.get('Authorization'))
            self.wfile.write('not authenticated')


server = HTTPServerV6(('::', 8080), AuthHandler)
server.serve_forever()