Modified Server to create and use SSLContext

Author: michalpokusa

Diff for: adafruit_httpserver/server.py

@@ -12,6 +12,7 @@
 except ImportError:
     pass
 
+from ssl import SSLContext, create_default_context
 from errno import EAGAIN, ECONNRESET, ETIMEDOUT
 from sys import implementation
 from time import monotonic, sleep
@@ -39,6 +40,9 @@
 REQUEST_HANDLED_NO_RESPONSE = "request_handled_no_response"
 REQUEST_HANDLED_RESPONSE_SENT = "request_handled_response_sent"
 
+# CircuitPython does not have these error codes
+MBEDTLS_ERR_SSL_FATAL_ALERT_MESSAGE = -30592
+
 
 class Server:  # pylint: disable=too-many-instance-attributes
     """A basic socket-based HTTP server."""
@@ -52,25 +56,57 @@ class Server:  # pylint: disable=too-many-instance-attributes
     root_path: str
     """Root directory to serve files from. ``None`` if serving files is disabled."""
 
+    @staticmethod
+    def _validate_https_cert_provided(certfile: str, keyfile: str) -> None:
+        if not certfile or not keyfile:
+            raise ValueError("Both certfile and keyfile must be specified for HTTPS")
+
+    @staticmethod
+    def _create_ssl_context(certfile: str, keyfile: str) -> SSLContext:
+        ssl_context = create_default_context()
+        ssl_context.load_verify_locations(cadata="")
+        ssl_context.load_cert_chain(certfile, keyfile)
+
+        return ssl_context
+
     def __init__(
-        self, socket_source: _ISocketPool, root_path: str = None, *, debug: bool = False
+        self,
+        socket_source: _ISocketPool,
+        root_path: str = None,
+        *,
+        https: bool = False,
+        certfile: str = None,
+        keyfile: str = None,
+        debug: bool = False,
     ) -> None:
         """Create a server, and get it ready to run.
 
         :param socket: An object that is a source of sockets. This could be a `socketpool`
           in CircuitPython or the `socket` module in CPython.
         :param str root_path: Root directory to serve files from
         :param bool debug: Enables debug messages useful during development
+        :param bool https: If True, the server will use HTTPS
+        :param str certfile: Path to the certificate file, required if ``https`` is True
+        :param str keyfile: Path to the private key file, required if ``https`` is True
         """
-        self._auths = []
         self._buffer = bytearray(1024)
         self._timeout = 1
+
+        self._auths = []
         self._routes: "List[Route]" = []
+        self.headers = Headers()
+
         self._socket_source = socket_source
         self._sock = None
-        self.headers = Headers()
+
         self.host, self.port = None, None
         self.root_path = root_path
+        self.https = https
+
+        if https:
+            self._validate_https_cert_provided(certfile, keyfile)
+            self._ssl_context = self._create_ssl_context(certfile, keyfile)
+
         if root_path in ["", "/"] and debug:
             _debug_warning_exposed_files(root_path)
         self.stopped = True
@@ -197,6 +233,7 @@ def serve_forever(
     @staticmethod
     def _create_server_socket(
         socket_source: _ISocketPool,
+        ssl_context: SSLContext,
         host: str,
         port: int,
     ) -> _ISocket:
@@ -206,6 +243,9 @@ def _create_server_socket(
         if implementation.version >= (9,) or implementation.name != "circuitpython":
             sock.setsockopt(socket_source.SOL_SOCKET, socket_source.SO_REUSEADDR, 1)
 
+        if ssl_context is not None:
+            sock = ssl_context.wrap_socket(sock, server_side=True)
+
         sock.bind((host, port))
         sock.listen(10)
         sock.setblocking(False)  # Non-blocking socket
@@ -225,7 +265,9 @@ def start(self, host: str = "0.0.0.0", port: int = 5000) -> None:
         self.host, self.port = host, port
 
         self.stopped = False
-        self._sock = self._create_server_socket(self._socket_source, host, port)
+        self._sock = self._create_server_socket(
+            self._socket_source, self._ssl_context, host, port
+        )
 
         if self.debug:
             _debug_started_server(self)
@@ -439,6 +481,8 @@ def poll(self) -> str:
                 # Connection reset by peer, try again later.
                 if error.errno == ECONNRESET:
                     return NO_REQUEST
+                if error.errno == MBEDTLS_ERR_SSL_FATAL_ALERT_MESSAGE:
+                    return NO_REQUEST
 
             if self.debug:
                 _debug_exception_in_handler(error)
@@ -547,9 +591,10 @@ def _debug_warning_exposed_files(root_path: str):
 
 def _debug_started_server(server: "Server"):
     """Prints a message when the server starts."""
+    scheme = "https" if server.https else "http"
     host, port = server.host, server.port
 
-    print(f"Started development server on http://{host}:{port}")
+    print(f"Started development server on {scheme}://{host}:{port}")
 
 
 def _debug_response_sent(response: "Response", time_elapsed: float):