[3.11] pythongh-103848: Adds checks to ensure that bracketed hosts found by urlsplit are of IPv6 or IPvFuture format (pythonGH-103849) (python#104349)

pythongh-103848: Adds checks to ensure that bracketed hosts found by urlsplit are of IPv6 or IPvFuture format (pythonGH-103849)

* Adds checks to ensure that bracketed hosts found by urlsplit are of IPv6 or IPvFuture format

---------

(cherry picked from commit 29f348e)

Co-authored-by: JohnJamesUtley <[email protected]>
Co-authored-by: Gregory P. Smith <[email protected]>

Author: 3 people

Lib/test/test_urlparse.py

@@ -1162,6 +1162,32 @@ def test_issue14072(self):
         self.assertEqual(p2.scheme, 'tel')
         self.assertEqual(p2.path, '+31641044153')
 
+    def test_invalid_bracketed_hosts(self):
+        self.assertRaises(ValueError, urllib.parse.urlsplit, 'Scheme://user@[192.0.2.146]/Path?Query')
+        self.assertRaises(ValueError, urllib.parse.urlsplit, 'Scheme://user@[important.com:8000]/Path?Query')
+        self.assertRaises(ValueError, urllib.parse.urlsplit, 'Scheme://user@[v123r.IP]/Path?Query')
+        self.assertRaises(ValueError, urllib.parse.urlsplit, 'Scheme://user@[v12ae]/Path?Query')
+        self.assertRaises(ValueError, urllib.parse.urlsplit, 'Scheme://user@[v.IP]/Path?Query')
+        self.assertRaises(ValueError, urllib.parse.urlsplit, 'Scheme://user@[v123.]/Path?Query')
+        self.assertRaises(ValueError, urllib.parse.urlsplit, 'Scheme://user@[v]/Path?Query')
+        self.assertRaises(ValueError, urllib.parse.urlsplit, 'Scheme://user@[0439:23af::2309::fae7:1234]/Path?Query')
+        self.assertRaises(ValueError, urllib.parse.urlsplit, 'Scheme://user@[0439:23af:2309::fae7:1234:2342:438e:192.0.2.146]/Path?Query')
+        self.assertRaises(ValueError, urllib.parse.urlsplit, 'Scheme://user@]v6a.ip[/Path')
+
+    def test_splitting_bracketed_hosts(self):
+        p1 = urllib.parse.urlsplit('scheme://user@[v6a.ip]/path?query')
+        self.assertEqual(p1.hostname, 'v6a.ip')
+        self.assertEqual(p1.username, 'user')
+        self.assertEqual(p1.path, '/path')
+        p2 = urllib.parse.urlsplit('scheme://user@[0439:23af:2309::fae7%test]/path?query')
+        self.assertEqual(p2.hostname, '0439:23af:2309::fae7%test')
+        self.assertEqual(p2.username, 'user')
+        self.assertEqual(p2.path, '/path')
+        p3 = urllib.parse.urlsplit('scheme://user@[0439:23af:2309::fae7:1234:192.0.2.146%test]/path?query')
+        self.assertEqual(p3.hostname, '0439:23af:2309::fae7:1234:192.0.2.146%test')
+        self.assertEqual(p3.username, 'user')
+        self.assertEqual(p3.path, '/path')
+
     def test_port_casting_failure_message(self):
         message = "Port could not be cast to integer value as 'oracle'"
         p1 = urllib.parse.urlparse('http://Server=sde; Service=sde:oracle')

Lib/urllib/parse.py

@@ -35,6 +35,7 @@
 import sys
 import collections
 import warnings
+import ipaddress
 
 __all__ = ["urlparse", "urlunparse", "urljoin", "urldefrag",
            "urlsplit", "urlunsplit", "urlencode", "parse_qs",
@@ -430,6 +431,18 @@ def _remove_unsafe_bytes_from_url(url):
         url = url.replace(b, "")
     return url
 
+
+# Valid bracketed hosts are defined in
+# https://www.rfc-editor.org/rfc/rfc3986#page-49 and https://url.spec.whatwg.org/
+def _check_bracketed_host(hostname):
+    if hostname.startswith('v'):
+        if not re.match(r"\Av[a-fA-F0-9]+\..+\Z", hostname):
+            raise ValueError(f"IPvFuture address is invalid")
+    else:
+        ip = ipaddress.ip_address(hostname) # Throws Value Error if not IPv6 or IPv4
+        if isinstance(ip, ipaddress.IPv4Address):
+            raise ValueError(f"An IPv4 address cannot be in brackets")
+
 def urlsplit(url, scheme='', allow_fragments=True):
     """Parse a URL into 5 components:
     <scheme>://<netloc>/<path>?<query>#<fragment>
@@ -484,6 +497,9 @@ def urlsplit(url, scheme='', allow_fragments=True):
         if (('[' in netloc and ']' not in netloc) or
                 (']' in netloc and '[' not in netloc)):
             raise ValueError("Invalid IPv6 URL")
+        if '[' in netloc and ']' in netloc:
+            bracketed_host = netloc.partition('[')[2].partition(']')[0]
+            _check_bracketed_host(bracketed_host)
     if allow_fragments and '#' in url:
         url, fragment = url.split('#', 1)
     if '?' in url: