Add the option to disable SSL (#8)

This allows the webserver to handle TLS, which is more flexible than the solution used internally. This is the approach used by nvdaremote.com

---------

Co-authored-by: Tyler Spivey <tspivey@pcdesk.net>

Author: SaschaCowley

server.py

@@ -6,17 +6,18 @@
 import time
 from collections import OrderedDict
 from logging import getLogger
+from typing import Any, TypedDict, cast
 
 from OpenSSL import crypto
 from twisted.internet import reactor, ssl
+from twisted.internet.defer import Deferred
 from twisted.internet.interfaces import ITCPTransport
-from twisted.internet.protocol import Factory, defer, connectionDone
+from twisted.internet.protocol import Factory, connectionDone, defer
 from twisted.internet.task import LoopingCall
 from twisted.protocols.basic import LineReceiver
+from twisted.protocols.haproxy._wrapper import HAProxyWrappingFactory
 from twisted.python import log, usage
-from twisted.internet.defer import Deferred
 from twisted.python.failure import Failure
-from typing import Any, TypedDict, cast
 
 logger = getLogger("remote-server")
 
@@ -363,27 +364,32 @@ class Options(usage.Options):
 		["network-interface", "i", "::", "Interface to listen on"],
 		["port", "p", "6837", "Server port"],
 	]
+	optFlags = [
+		["no-ssl", "n", "Disable SSL"],
+	]
 
 
 # Exclude from coverage as it's hard to unit test.
 def main() -> Deferred[None]:  # pragma: no cover
+	sslContext: ssl.CertificateOptions | None = None
 	# Read options from CLI.
 	config = Options()
 	config.parseOptions()
-	# Open SSL keys.
-	privkey = open(config["privkey"]).read()
-	certData = open(config["certificate"], "rb").read()
-	chain = open(config["chain"], "rb").read()
 	log.startLogging(sys.stdout)
-	# Initialise encryption
-	privkey = crypto.load_privatekey(crypto.FILETYPE_PEM, privkey)
-	certificate = crypto.load_certificate(crypto.FILETYPE_PEM, certData)
-	chain = crypto.load_certificate(crypto.FILETYPE_PEM, chain)
-	contextFactory = ssl.CertificateOptions(
-		privateKey=privkey,
-		certificate=certificate,
-		extraCertChain=[chain],
-	)
+	if not config["no-ssl"]:
+		# Initialise encryption
+		# Open SSL keys.
+		privkey = open(config["privkey"]).read()
+		certData = open(config["certificate"], "rb").read()
+		chain = open(config["chain"], "rb").read()
+		privkey = crypto.load_privatekey(crypto.FILETYPE_PEM, privkey)
+		certificate = crypto.load_certificate(crypto.FILETYPE_PEM, certData)
+		chain = crypto.load_certificate(crypto.FILETYPE_PEM, chain)
+		sslContext = ssl.CertificateOptions(
+			privateKey=privkey,
+			certificate=certificate,
+			extraCertChain=[chain],
+		)
 	# Initialise the server state machine
 	state = ServerState()
 	if os.path.isfile(config["motd"]):
@@ -393,11 +399,15 @@ def main() -> Deferred[None]:  # pragma: no cover
 		state.motd = None
 	# Set up the machinery of the server.
 	factory = RemoteServerFactory(state)
+	wrappedFactory = HAProxyWrappingFactory(factory)
 	looper = LoopingCall(factory.pingConnectedClients)
 	looper.start(PING_INTERVAL)
 	factory.protocol = Handler
 	# Start running the server.
-	reactor.listenSSL(int(config["port"]), factory, contextFactory, interface=config["network-interface"])
+	if config["no-ssl"]:
+		reactor.listenTCP(int(config["port"]), wrappedFactory, interface=config["network-interface"])
+	else:
+		reactor.listenSSL(int(config["port"]), factory, sslContext, interface=config["network-interface"])
 	reactor.run()
 	return defer.Deferred()