Add commandline arguments for supplying a client CA

examples/echo_server.py

@@ -14,11 +14,13 @@ def echo(environ, send_status):
 
 if __name__ == "__main__":
     args = jetforce.command_line_parser().parse_args()
+    ssl_context = jetforce.make_ssl_context(
+        args.hostname, args.certfile, args.keyfile, args.cafile, args.capath
+    )
     server = jetforce.GeminiServer(
         host=args.host,
         port=args.port,
-        certfile=args.certfile,
+        ssl_context=ssl_context,
-        keyfile=args.keyfile,
         hostname=args.hostname,
         app=echo,
     )

examples/guestbook.py

@@ -24,7 +24,6 @@ def index(request):
         for line in fp:
             line = line.strip()
             if line.startswith("=>"):
-                # Protect guests from writing messages that contain links
                 data.append(line[2:])
             else:
                 data.append(line)
@@ -40,6 +39,7 @@ def submit(request):
         created = datetime.utcnow()
         with guestbook.open("a") as fp:
             fp.write(f"\n[{created:%Y-%m-%d %I:%M %p}]\n{message}\n")
+
         return Response(Status.REDIRECT_TEMPORARY, "")
     else:
         return Response(Status.INPUT, "Enter your message (max 256 characters)")
@@ -47,11 +47,13 @@ def submit(request):
 
 if __name__ == "__main__":
     args = jetforce.command_line_parser().parse_args()
+    ssl_context = jetforce.make_ssl_context(
+        args.hostname, args.certfile, args.keyfile, args.cafile, args.capath
+    )
     server = jetforce.GeminiServer(
         host=args.host,
         port=args.port,
-        certfile=args.certfile,
+        ssl_context=ssl_context,
-        keyfile=args.keyfile,
         hostname=args.hostname,
         app=app,
     )

examples/http_proxy.py

@@ -27,11 +27,13 @@ def proxy_request(request):
 
 if __name__ == "__main__":
     args = jetforce.command_line_parser().parse_args()
+    ssl_context = jetforce.make_ssl_context(
+        args.hostname, args.certfile, args.keyfile, args.cafile, args.capath
+    )
     server = jetforce.GeminiServer(
         host=args.host,
         port=args.port,
-        certfile=args.certfile,
+        ssl_context=ssl_context,
-        keyfile=args.keyfile,
         hostname=args.hostname,
         app=app,
     )

jetforce.py

@@ -1,4 +1,6 @@
 #!/usr/bin/env python3.7
+from __future__ import annotations
+
 import argparse
 import asyncio
 import codecs
@@ -83,7 +85,6 @@ class Request:
 
     def __init__(self, environ: dict):
         self.environ = environ
-
         self.url = environ["GEMINI_URL"]
 
         url_parts = urllib.parse.urlparse(self.url)
@@ -92,7 +93,7 @@ class Request:
         self.port = url_parts.port
         self.path = url_parts.path
         self.params = url_parts.params
-        self.query = url_parts.query
+        self.query = urllib.parse.unquote(url_parts.query)
         self.fragment = url_parts.fragment
 
 
@@ -258,11 +259,17 @@ class StaticDirectoryApplication(JetforceApplication):
             return Response(Status.NOT_FOUND, "Not Found")
 
     def run_cgi_script(self, filesystem_path: pathlib.Path, environ: dict) -> Response:
+        """
+        Execute the given file as a CGI script and return the script's stdout
+        stream to the client.
+        """
         script_name = str(filesystem_path)
         cgi_env = environ.copy()
         cgi_env["GATEWAY_INTERFACE"] = "GCI/1.1"
         cgi_env["SCRIPT_NAME"] = script_name
 
+        # Decode the stream as unicode so we can parse the status line
+        # Use surrogateescape to preserve any non-UTF8 byte sequences.
         out = subprocess.Popen(
             [script_name],
             stdout=subprocess.PIPE,
@@ -334,7 +341,7 @@ class GeminiRequestHandler:
     removed or slimmed-down.
     """
 
-    def __init__(self, server: "GeminiServer", app: typing.Callable) -> None:
+    def __init__(self, server: GeminiServer, app: typing.Callable) -> None:
         self.server = server
         self.app = app
         self.reader: typing.Optional[asyncio.StreamReader] = None
@@ -488,8 +495,7 @@ class GeminiServer:
         app: typing.Callable,
         host: str = "127.0.0.1",
         port: int = 1965,
-        certfile: typing.Optional[str] = None,
+        ssl_context: ssl.SSLContext = None,
-        keyfile: typing.Optional[str] = None,
         hostname: str = "localhost",
     ) -> None:
 
@@ -497,14 +503,7 @@ class GeminiServer:
         self.port = port
         self.hostname = hostname
         self.app = app
-
+        self.ssl_context = ssl_context
-        if not certfile:
-            certfile, keyfile = self.generate_tls_certificate(hostname)
-
-        self.ssl_context = ssl.SSLContext()
-        self.ssl_context.verify_mode = ssl.CERT_OPTIONAL
-        self.ssl_context.check_hostname = False
-        self.ssl_context.load_cert_chain(certfile, keyfile)
 
     async def run(self) -> None:
         """
@@ -540,8 +539,8 @@ class GeminiServer:
         """
         print(message, file=sys.stderr)
 
-    @staticmethod
+
-    def generate_tls_certificate(hostname: str) -> typing.Tuple[str, str]:
+def generate_ad_hoc_certificate(hostname: str) -> typing.Tuple[str, str]:
     """
     Utility function to generate a self-signed SSL certificate key pair if
     one isn't provided. Results may vary depending on your version of OpenSSL.
@@ -561,10 +560,50 @@ class GeminiServer:
     return str(certfile), str(keyfile)
 
 
+def make_ssl_context(
+    hostname: str = "localhost",
+    certfile: typing.Optional[str] = None,
+    keyfile: typing.Optional[str] = None,
+    cafile: typing.Optional[str] = None,
+    capath: typing.Optional[str] = None,
+) -> ssl.SSLContext:
+    """
+    Generate a sane default SSL context for a Gemini server.
+
+    For more information on what these variables mean and what values they can
+    contain, see the python standard library documentation:
+
+        https://docs.python.org/3/library/ssl.html#ssl-contexts
+
+    verify_mode: ssl.CERT_OPTIONAL
+        A client certificate request is sent to the client. The client may
+        either ignore the request or send a certificate in order perform TLS
+        client cert authentication. If the client chooses to send a certificate,
+        it is verified. Any verification error immediately aborts the TLS
+        handshake.
+    """
+    if certfile is None:
+        certfile, keyfile = generate_ad_hoc_certificate(hostname)
+
+    context = ssl.SSLContext()
+    context.verify_mode = ssl.CERT_OPTIONAL
+    context.load_cert_chain(certfile, keyfile)
+
+    if not cafile and not capath:
+        # Load from the system's default client CA directory
+        context.load_default_certs(purpose=ssl.Purpose.CLIENT_AUTH)
+    else:
+        # Use a custom CA for validating client certificates
+        context.load_verify_locations(cafile, capath)
+
+    return context
+
+
 def command_line_parser() -> argparse.ArgumentParser:
     """
     Construct the default argument parser when launching the server from
-    the command line.
+    the command line. These are meant to be application-agnostic arguments
+    that could apply to any subclass of the JetforceApplication.
     """
     parser = argparse.ArgumentParser(
         prog="jetforce",
@@ -574,6 +613,7 @@ def command_line_parser() -> argparse.ArgumentParser:
     )
     parser.add_argument("--host", help="Server address to bind to", default="127.0.0.1")
     parser.add_argument("--port", help="Server port to bind to", type=int, default=1965)
+    parser.add_argument("--hostname", help="Server hostname", default="localhost")
     parser.add_argument(
         "--tls-certfile",
         dest="certfile",
@@ -586,7 +626,18 @@ def command_line_parser() -> argparse.ArgumentParser:
         help="Server TLS private key file",
         metavar="FILE",
     )
-    parser.add_argument("--hostname", help="Server hostname", default="localhost")
+    parser.add_argument(
+        "--tls-cafile",
+        dest="cafile",
+        help="A CA file to use for validating clients",
+        metavar="FILE",
+    )
+    parser.add_argument(
+        "--tls-capath",
+        dest="capath",
+        help="A directory containing CA files for validating clients",
+        metavar="DIR",
+    )
     return parser
 
 
@@ -617,11 +668,13 @@ def run_server() -> None:
     args = parser.parse_args()
 
     app = StaticDirectoryApplication(args.dir, args.index_file, args.cgi_dir)
+    ssl_context = make_ssl_context(
+        args.hostname, args.certfile, args.keyfile, args.cafile, args.capath
+    )
     server = GeminiServer(
         host=args.host,
         port=args.port,
-        certfile=args.certfile,
+        ssl_context=ssl_context,
-        keyfile=args.keyfile,
         hostname=args.hostname,
         app=app,
     )