diff options
| -rw-r--r-- | Doc/library/urllib.parse.rst | 18 | ||||
| -rw-r--r-- | Lib/test/test_urlparse.py | 23 | ||||
| -rw-r--r-- | Lib/urllib/parse.py | 17 | ||||
| -rw-r--r-- | Misc/NEWS.d/next/Security/2019-03-06-09-38-40.bpo-36216.6q1m4a.rst | 3 |
4 files changed, 61 insertions, 0 deletions
diff --git a/Doc/library/urllib.parse.rst b/Doc/library/urllib.parse.rst index 913e933..af15f5b 100644 --- a/Doc/library/urllib.parse.rst +++ b/Doc/library/urllib.parse.rst @@ -124,6 +124,11 @@ or on combining URL components into a URL string. Unmatched square brackets in the :attr:`netloc` attribute will raise a :exc:`ValueError`. + Characters in the :attr:`netloc` attribute that decompose under NFKC + normalization (as used by the IDNA encoding) into any of ``/``, ``?``, + ``#``, ``@``, or ``:`` will raise a :exc:`ValueError`. If the URL is + decomposed before parsing, no error will be raised. + .. versionchanged:: 3.2 Added IPv6 URL parsing capabilities. @@ -136,6 +141,10 @@ or on combining URL components into a URL string. Out-of-range port numbers now raise :exc:`ValueError`, instead of returning :const:`None`. + .. versionchanged:: 3.8 + Characters that affect netloc parsing under NFKC normalization will + now raise :exc:`ValueError`. + .. function:: parse_qs(qs, keep_blank_values=False, strict_parsing=False, encoding='utf-8', errors='replace', max_num_fields=None) @@ -259,10 +268,19 @@ or on combining URL components into a URL string. Unmatched square brackets in the :attr:`netloc` attribute will raise a :exc:`ValueError`. + Characters in the :attr:`netloc` attribute that decompose under NFKC + normalization (as used by the IDNA encoding) into any of ``/``, ``?``, + ``#``, ``@``, or ``:`` will raise a :exc:`ValueError`. If the URL is + decomposed before parsing, no error will be raised. + .. versionchanged:: 3.6 Out-of-range port numbers now raise :exc:`ValueError`, instead of returning :const:`None`. + .. versionchanged:: 3.8 + Characters that affect netloc parsing under NFKC normalization will + now raise :exc:`ValueError`. + .. function:: urlunsplit(parts) diff --git a/Lib/test/test_urlparse.py b/Lib/test/test_urlparse.py index 9c71be5..0faf2bb 100644 --- a/Lib/test/test_urlparse.py +++ b/Lib/test/test_urlparse.py @@ -1,3 +1,5 @@ +import sys +import unicodedata import unittest import urllib.parse @@ -994,6 +996,27 @@ class UrlParseTestCase(unittest.TestCase): expected.append(name) self.assertCountEqual(urllib.parse.__all__, expected) + def test_urlsplit_normalization(self): + # Certain characters should never occur in the netloc, + # including under normalization. + # Ensure that ALL of them are detected and cause an error + illegal_chars = '/:#?@' + hex_chars = {'{:04X}'.format(ord(c)) for c in illegal_chars} + denorm_chars = [ + c for c in map(chr, range(128, sys.maxunicode)) + if (hex_chars & set(unicodedata.decomposition(c).split())) + and c not in illegal_chars + ] + # Sanity check that we found at least one such character + self.assertIn('\u2100', denorm_chars) + self.assertIn('\uFF03', denorm_chars) + + for scheme in ["http", "https", "ftp"]: + for c in denorm_chars: + url = "{}://netloc{}false.netloc/path".format(scheme, c) + with self.subTest(url=url, char='{:04X}'.format(ord(c))): + with self.assertRaises(ValueError): + urllib.parse.urlsplit(url) class Utility_Tests(unittest.TestCase): """Testcase to test the various utility functions in the urllib.""" diff --git a/Lib/urllib/parse.py b/Lib/urllib/parse.py index dc21711..8b6c9b1 100644 --- a/Lib/urllib/parse.py +++ b/Lib/urllib/parse.py @@ -396,6 +396,21 @@ def _splitnetloc(url, start=0): delim = min(delim, wdelim) # use earliest delim position return url[start:delim], url[delim:] # return (domain, rest) +def _checknetloc(netloc): + if not netloc or netloc.isascii(): + return + # looking for characters like \u2100 that expand to 'a/c' + # IDNA uses NFKC equivalence, so normalize for this check + import unicodedata + netloc2 = unicodedata.normalize('NFKC', netloc) + if netloc == netloc2: + return + _, _, netloc = netloc.rpartition('@') # anything to the left of '@' is okay + for c in '/?#@:': + if c in netloc2: + raise ValueError("netloc '" + netloc2 + "' contains invalid " + + "characters under NFKC normalization") + def urlsplit(url, scheme='', allow_fragments=True): """Parse a URL into 5 components: <scheme>://<netloc>/<path>?<query>#<fragment> @@ -424,6 +439,7 @@ def urlsplit(url, scheme='', allow_fragments=True): url, fragment = url.split('#', 1) if '?' in url: url, query = url.split('?', 1) + _checknetloc(netloc) v = SplitResult('http', netloc, url, query, fragment) _parse_cache[key] = v return _coerce_result(v) @@ -447,6 +463,7 @@ def urlsplit(url, scheme='', allow_fragments=True): url, fragment = url.split('#', 1) if '?' in url: url, query = url.split('?', 1) + _checknetloc(netloc) v = SplitResult(scheme, netloc, url, query, fragment) _parse_cache[key] = v return _coerce_result(v) diff --git a/Misc/NEWS.d/next/Security/2019-03-06-09-38-40.bpo-36216.6q1m4a.rst b/Misc/NEWS.d/next/Security/2019-03-06-09-38-40.bpo-36216.6q1m4a.rst new file mode 100644 index 0000000..5546394 --- /dev/null +++ b/Misc/NEWS.d/next/Security/2019-03-06-09-38-40.bpo-36216.6q1m4a.rst @@ -0,0 +1,3 @@ +Changes urlsplit() to raise ValueError when the URL contains characters that +decompose under IDNA encoding (NFKC-normalization) into characters that +affect how the URL is parsed. |