Add serverCertificateHashes test server

Add a second webtransport server, in order to test connection with a
server, that has a self-signed certificate together with
serverCertificateHashes.

See web-platform-tests/rfcs#216

Author: jgraham

tools/serve/serve.py

@@ -15,6 +15,7 @@
 import traceback
 import urllib
 import uuid
+import datetime
 from collections import defaultdict, OrderedDict
 from io import IOBase
 from itertools import chain, product
@@ -991,7 +992,7 @@ def start_servers(logger, host, ports, paths, routes, bind_address, config,
             continue
 
         # Skip WebTransport over HTTP/3 server unless if is enabled explicitly.
-        if scheme == 'webtransport-h3' and not kwargs.get("webtransport_h3"):
+        if scheme in ['webtransport-h3', 'webtransport-h3-cert-hash'] and not kwargs.get("webtransport_h3"):
             continue
 
         for port in ports:
@@ -1009,6 +1010,7 @@ def start_servers(logger, host, ports, paths, routes, bind_address, config,
                 "ws": start_ws_server,
                 "wss": start_wss_server,
                 "webtransport-h3": start_webtransport_h3_server,
+                "webtransport-h3-cert-hash": start_webtransport_h3_server_cert_hash,
             }[scheme]
 
             server_proc = ServerProc(mp_context, scheme=scheme)
@@ -1174,18 +1176,40 @@ def start_webtransport_h3_server(logger, host, port, paths, routes, bind_address
     try:
         # TODO(bashi): Move the following import to the beginning of this file
         # once WebTransportH3Server is enabled by default.
-        from webtransport.h3.webtransport_h3_server import WebTransportH3Server  # type: ignore
+        from webtransport.h3.webtransport_h3_server import WebTransportH3Server, WebTransportCertificateGeneration  # type: ignore
         return WebTransportH3Server(host=host,
                                     port=port,
                                     doc_root=paths["doc_root"],
+                                    cert_mode=WebTransportCertificateGeneration.USEPREGENERATED,
                                     cert_path=config.ssl_config["cert_path"],
                                     key_path=config.ssl_config["key_path"],
-                                    logger=logger)
+                                    logger=logger,
+                                    cert_hash_info=None
+                                    )
     except Exception as error:
         logger.critical(
             f"Failed to start WebTransport over HTTP/3 server: {error}")
         sys.exit(0)
 
+def start_webtransport_h3_server_cert_hash(logger, host, port, paths, routes, bind_address, config, **kwargs):
+    try:
+        # TODO(bashi): Move the following import to the beginning of this file
+        # once WebTransportH3Server is enabled by default.
+        from webtransport.h3.webtransport_h3_server import WebTransportH3Server, WebTransportCertificateGeneration
+        return WebTransportH3Server(host=host,
+                                    port=port,
+                                    doc_root=paths["doc_root"],
+                                    cert_mode=WebTransportCertificateGeneration.GENERATEDVALIDSERVERCERTIFICATEHASHCERT,
+                                    cert_path=None,
+                                    key_path=None,
+                                    logger=logger,
+                                    cert_hash_info=config["cert_hash_info"]
+                                    )
+    except Exception as error:
+        logger.critical(
+            f"Failed to start WebTransport over HTTP/3 server with certificate hashes: {error}")
+        sys.exit(0)
+
 
 def start(logger, config, routes, mp_context, log_handlers, **kwargs):
     host = config["server_host"]
@@ -1249,6 +1273,7 @@ class ConfigBuilder(config.ConfigBuilder):
             "ws": ["auto"],
             "wss": ["auto"],
             "webtransport-h3": ["auto"],
+            "webtransport-h3-cert-hash": ["auto"],
         },
         "check_subdomains": True,
         "bind_address": True,
@@ -1372,7 +1397,7 @@ def get_parser():
     parser.add_argument("--no-h2", action="store_false", dest="h2", default=None,
                         help="Disable the HTTP/2.0 server")
     parser.add_argument("--webtransport-h3", action="store_true",
-                        help="Enable WebTransport over HTTP/3 server")
+                        help="Enable WebTransport over HTTP/3 servers")
     parser.add_argument("--exit-after-start", action="store_true",
                         help="Exit after starting servers")
     parser.add_argument("--verbose", action="store_true", help="Enable verbose logging")

tools/webtransport/h3/webtransport_h3_server.py

@@ -8,10 +8,13 @@
 import sys
 import threading
 import traceback
-from enum import IntEnum
+from enum import IntEnum, Enum
 from urllib.parse import urlparse
 from typing import Any, Dict, List, Optional, Tuple, cast
 
+from cryptography import x509
+from cryptography.hazmat.primitives import serialization
+
 # TODO(bashi): Remove import check suppressions once aioquic dependency is resolved.
 from aioquic.buffer import Buffer  # type: ignore
 from aioquic.asyncio import QuicConnectionProtocol, serve  # type: ignore
@@ -31,6 +34,7 @@
 from tools import localpaths  # noqa: F401
 from wptserve import stash
 from .capsule import H3Capsule, H3CapsuleDecoder, CapsuleType
+from http.server import BaseHTTPRequestHandler, HTTPServer
 
 """
 A WebTransport over HTTP/3 server for testing.
@@ -499,6 +503,16 @@ def add(self, ticket: SessionTicket) -> None:
     def pop(self, label: bytes) -> Optional[SessionTicket]:
         return self.tickets.pop(label, None)
 
+class WebTransportCertificateGeneration(Enum):
+    """
+    Specify, if the server should generate a certificate or use an existing certificate
+     USEPREGENERATED: use existing certificate
+     GENERATEDVALIDSERVERCERTIFICATEHASHCERT: generate a certificate compatible to server cert hashes
+    """
+    USEPREGENERATED = 1,
+    GENERATEDVALIDSERVERCERTIFICATEHASHCERT = 2
+# TODO add cases for invalid certificates
+
 
 class WebTransportH3Server:
     """
@@ -507,18 +521,31 @@ class WebTransportH3Server:
     :param host: Host from which to serve.
     :param port: Port from which to serve.
     :param doc_root: Document root for serving handlers.
+    :paran cert_mode: The used certificate mode can be
+       USEPREGENERATED or GENERATEDVALIDSERVERCERTIFICATEHASHCERT
     :param cert_path: Path to certificate file to use.
     :param key_path: Path to key file to use.
     :param logger: a Logger object for this server.
     """
 
-    def __init__(self, host: str, port: int, doc_root: str, cert_path: str,
-                 key_path: str, logger: Optional[logging.Logger]) -> None:
+    def __init__(self, host: str, port: int, doc_root: str, cert_mode: WebTransportCertificateGeneration,
+                 cert_path: Optional[str], key_path: Optional[str], logger: Optional[logging.Logger],
+                 cert_hash_info: Optional[Dict]) -> None:
         self.host = host
         self.port = port
         self.doc_root = doc_root
-        self.cert_path = cert_path
-        self.key_path = key_path
+        if cert_path is not None:
+            self.cert_path = cert_path
+        if key_path is not None:
+            self.key_path = key_path
+        if cert_hash_info is not None:
+            self.cert_hash_info = cert_hash_info
+        self.cert_mode = cert_mode
+        if (cert_path is None or key_path is None) and cert_mode == WebTransportCertificateGeneration.USEPREGENERATED:
+            raise ValueError("Both cert_path and key_path must be provided, if cert_mode is USEPREGENERATED")
+        if (cert_hash_info is None and cert_mode == WebTransportCertificateGeneration.GENERATEDVALIDSERVERCERTIFICATEHASHCERT):
+            raise ValueError("cert_hash_info  must be provided, if cert_mode is GENERATEDVALIDSERVERCERTIFICATEHASHCERT")
+
         self.started = False
         global _doc_root
         _doc_root = self.doc_root
@@ -551,7 +578,16 @@ def _start_on_server_thread(self) -> None:
         _logger.info("Starting WebTransport over HTTP/3 server on %s:%s",
                      self.host, self.port)
 
-        configuration.load_cert_chain(self.cert_path, self.key_path)
+        if self.cert_mode == WebTransportCertificateGeneration.USEPREGENERATED:
+            configuration.load_cert_chain(self.cert_path, self.key_path)
+        else: # GENERATEDVALIDSERVERCERTIFICATEHASHCERT case
+            configuration.private_key =  serialization.load_pem_private_key(self.cert_hash_info["private_key"],
+                                                                            password=None
+                                                                            )
+            configuration.certificate = x509.load_pem_x509_certificate(self.cert_hash_info["certificate"])
+            configuration.certificate_chain = []
+
+
 
         ticket_store = SessionTicketStore()
 

tools/webtransport/requirements.txt

@@ -1 +1,2 @@
 aioquic==1.2.0
+cryptography

tools/wptrunner/wptrunner/environment.py

@@ -9,8 +9,14 @@
 import socket
 import sys
 import time
+import datetime
 from typing import Optional
 
+from cryptography.hazmat.primitives.asymmetric import ec
+from cryptography.hazmat.primitives import hashes, serialization
+from cryptography.x509.oid import NameOID
+from cryptography import x509
+
 import mozprocess
 from mozlog import get_default_logger, handlers
 from mozlog.structuredlog import StructuredLogger
@@ -46,6 +52,37 @@ def do_delayed_imports(logger, test_paths):
             (", ".join(failed), serve_root))
         sys.exit(1)
 
+def generate_hash_certificate(host: str) -> str:
+    private_key = ec.generate_private_key(ec.SECP256R1())
+    subject = issuer = x509.Name([
+        x509.NameAttribute(NameOID.COUNTRY_NAME, "DE"),
+        x509.NameAttribute(NameOID.STATE_OR_PROVINCE_NAME, "Berlin"),
+        x509.NameAttribute(NameOID.LOCALITY_NAME, "Berlin"),
+        x509.NameAttribute(NameOID.ORGANIZATION_NAME, "Wpt tests"),
+        x509.NameAttribute(NameOID.COMMON_NAME, host),
+    ])
+    now = datetime.datetime.now(datetime.timezone.utc)
+    certificate = (
+        x509.CertificateBuilder()
+        .subject_name(subject)
+        .issuer_name(issuer)
+        .public_key(private_key.public_key())
+        .serial_number(x509.random_serial_number())
+        .not_valid_before(now)
+        .not_valid_after(now + datetime.timedelta(days=13))
+        .sign(private_key, hashes.SHA256())
+    )
+    fingerprint = certificate.fingerprint(hashes.SHA256())
+    server_certificate_hash = ":".join(f"{byte:02x}" for byte in fingerprint)
+    return { "certificate": certificate.public_bytes(
+             encoding=serialization.Encoding.PEM
+             ),
+             "private_key": private_key.private_bytes(
+                encoding=serialization.Encoding.PEM,
+                format=serialization.PrivateFormat.TraditionalOpenSSL,
+                encryption_algorithm=serialization.NoEncryption()),
+             "hash": server_certificate_hash
+            }
 
 def serve_path(test_paths):
     return test_paths["/"].tests_path
@@ -150,7 +187,8 @@ def __enter__(self):
                                    self.get_routes(),
                                    mp_context=mpcontext.get_context(),
                                    log_handlers=[server_log_handler],
-                                   webtransport_h3=self.enable_webtransport)
+                                   webtransport_h3=self.enable_webtransport,
+                                   webtransport_h3_cert_hash=self.enable_webtransport)
 
         if self.options.get("supports_debugger") and self.debug_info and self.debug_info.interactive:
             self._stack.enter_context(self.ignore_interrupts())
@@ -197,6 +235,7 @@ def build_config(self):
             "wss": [8889],
             "h2": [9000],
             "webtransport-h3": [11000],
+            "webtransport-h3-cert-hash": [11001],
         }
         config.ports = ports
 
@@ -221,6 +260,8 @@ def build_config(self):
         config.doc_root = serve_path(self.test_paths)
         config.inject_script = self.inject_script
 
+        config.cert_hash_info = generate_hash_certificate(config.server_host)
+
         if self.suppress_handler_traceback is not None:
             config.logging["suppress_handler_traceback"] = self.suppress_handler_traceback
 
@@ -323,10 +364,15 @@ def test_servers(self):
             for port, server in self.servers.get("webtransport-h3", []):
                 if not webtranport_h3_server_is_running(host, port, timeout=5):
                     pending.append((host, port))
+            for port, server in self.servers.get("webtransport-h3-cert-hash", []):
+                if not webtranport_h3_server_is_running(host, port, timeout=5):
+                    pending.append((host, port))
 
             for scheme, servers in self.servers.items():
                 if scheme == "webtransport-h3":
                     continue
+                if scheme == "webtransport-h3-cert-hash":
+                    continue
                 for port, server in servers:
                     s = socket.socket()
                     s.settimeout(0.1)

tools/wptserve/wptserve/config.py

@@ -128,6 +128,7 @@ class ConfigBuilder:
 
     _default = {
         "browser_host": "localhost",
+        "certificate_hash": {},
         "alternate_hosts": {},
         "doc_root": os.path.dirname("__file__"),
         "server_host": None,

tools/wptserve/wptserve/pipes.py

@@ -478,6 +478,8 @@ def config_replacement(match):
             value = variables[field]
         elif hasattr(SubFunctions, field):
             value = getattr(SubFunctions, field)
+        elif field == "server_certificate_hash":
+            value = request.server.config["cert_hash_info"]["hash"]
         elif field == "headers":
             value = request.headers
         elif field == "GET":

webtransport/resources/webtransport-test-helpers.sub.js

@@ -3,16 +3,23 @@
 
 const HOST = get_host_info().ORIGINAL_HOST;
 const PORT = '{{ports[webtransport-h3][0]}}';
+const PORT_CERT_HASH = '{{ports[webtransport-h3-cert-hash][0]}}';
 const BASE = `https://${HOST}:${PORT}`;
+const BASE_CERT_HASH = `https://${HOST}:${PORT_CERT_HASH}`;
 
 // Wait for the given number of milliseconds (ms).
 function wait(ms) { return new Promise(res => step_timeout(res, ms)); }
 
 // Create URL for WebTransport session.
-function webtransport_url(handler) {
+function webtransport_url(handler, options) {
+  if (options?.cert_hashes) {
+    return `${BASE_CERT_HASH}/webtransport/handlers/${handler}`;
+  }
   return `${BASE}/webtransport/handlers/${handler}`;
 }
 
+const cert_hash = new Uint8Array('{{server_certificate_hash}}'.split(':').map((el) => parseInt(el, 16)));
+const cert_hash_str = '{{server_certificate_hash}}'
 // Converts WebTransport stream error code to HTTP/3 error code.
 // https://ietf-wg-webtrans.github.io/draft-ietf-webtrans-http3/draft-ietf-webtrans-http3.html#section-4.3
 function webtransport_code_to_http_code(n) {