fix(lab-ops-hub): refuse DEL/C1/NBSP and WHATWG-forbidden hosts in container validator (#510)

pkgs/lab-ops-hub/container/app.py

@@ -65,12 +65,16 @@ def validate_crawl_url(raw):
     # the zone id). Refuse every % host, fail-closed (#505).
     if "%" in host:
         raise ValueError(f"refusing to crawl percent-encoded host {host}")
-    # A space or control character in the host is not a DNS name: WHATWG
-    # rejects it outright, urlparse hands it through verbatim, and
-    # http.client only raises for it deep inside the fetcher — the same
-    # lazy-failure shape #502 fixed for ports. Refuse up front (#507).
-    if any(ord(c) <= 0x20 for c in host):
-        raise ValueError(f"refusing to crawl host with whitespace {host!r}")
+    # A space, control or WHATWG-forbidden character in the host is not
+    # a DNS name: WHATWG rejects it outright, urlparse hands it through
+    # verbatim, and http.client only raises for it deep inside the
+    # fetcher — the same lazy-failure shape #502 fixed for ports. Refuse
+    # up front: C0 controls and space (#507), plus DEL, the C1 controls
+    # and NBSP (0x7F-0xA0) and the forbidden host codepoints < > ^ |
+    # (#510). Non-ASCII above NBSP (a valid IDN host, e.g. é) is
+    # untouched.
+    if any(ord(c) <= 0x20 or 0x7F <= ord(c) <= 0xA0 or c in "<>^|" for c in host):
+        raise ValueError(f"refusing to crawl host with a forbidden character {host!r}")
     if host == "localhost" or host.endswith(_BLOCKED_SUFFIXES):
         raise ValueError(f"refusing to crawl local host {host}")
     try:

pkgs/lab-ops-hub/test/test_container_validate.py

@@ -248,6 +248,29 @@ def test_refuses_space_hosts_and_ipvfuture_literals(self):
         ):
             self.assertRefused(url)
 
+    def test_refuses_del_c1_nbsp_and_forbidden_host_characters(self):
+        # The #507 check stopped at 0x20, one codepoint short of
+        # http.client's own set and short of the rest of the WHATWG
+        # forbidden-host set: DEL, the C1 controls, NBSP and < > ^ |
+        # still fell through as "a public DNS name", while the
+        # Worker's WHATWG validator refuses every one (#510).
+        for url in (
+            "http://exam\x7fple.com/",  # DEL
+            "http://exam\x80ple.com/",  # C1 control, low end
+            "http://exam\x85ple.com/",  # C1 control (NEL)
+            "http://exam\x9fple.com/",  # C1 control, high end
+            "http://exam\xa0ple.com/",  # NBSP
+            "http://exam<ple.com/",
+            "http://exam>ple.com/",
+            "http://exam^ple.com/",
+            "http://exam|ple.com/",
+        ):
+            self.assertRefused(url)
+        # Controls: characters above NBSP and ordinary DNS punctuation
+        # are not forbidden — valid IDN hosts stay crawlable.
+        self.assertAccepted("http://exam_ple.com/")
+        self.assertAccepted("http://examéple.com/")
+
     def test_accepts_public_targets(self):
         for url in (
             "https://example.com/page",