Raise ValueError if method contains control characters (#1800)

CHANGES.rst

@@ -1,6 +1,13 @@
 Changes
 =======
 
+master (dev)
+------------
+
+* Raise ``ValueError`` if control characters are given in
+  the ``method`` parameter of ``HTTPConnection.request()`` (Pull #1800)
+
+
 1.25.8 (2020-01-20)
 -------------------
 

src/urllib3/connection.py

@@ -1,4 +1,5 @@
 from __future__ import absolute_import
+import re
 import datetime
 import logging
 import os
@@ -58,6 +59,8 @@ class ConnectionError(Exception):
 # (ie test_recent_date is failing) update it to ~6 months before the current date.
 RECENT_DATE = datetime.date(2019, 1, 1)
 
+_CONTAINS_CONTROL_CHAR_RE = re.compile(r"[^-!#$%&'*+.^_`|~0-9a-zA-Z]")
+
 
 class DummyConnection(object):
     """Used to detect a failed ConnectionCls import."""
@@ -184,6 +187,17 @@ def connect(self):
         conn = self._new_conn()
         self._prepare_conn(conn)
 
+    def putrequest(self, method, url, *args, **kwargs):
+        """Send a request to the server"""
+        match = _CONTAINS_CONTROL_CHAR_RE.search(method)
+        if match:
+            raise ValueError(
+                "Method cannot contain non-token characters %r (found at least %r)"
+                % (method, match.group())
+            )
+
+        return _HTTPConnection.putrequest(self, method, url, *args, **kwargs)
+
     def request_chunked(self, method, url, body=None, headers=None):
         """
         Alternative to the common request method, which sends the

test/with_dummyserver/test_connectionpool.py

@@ -677,6 +677,12 @@ def test_dns_error(self):
             with pytest.raises(MaxRetryError):
                 pool.request("GET", "/test", retries=2)
 
+    @pytest.mark.parametrize("char", [" ", "\r", "\n", "\x00"])
+    def test_invalid_method_not_allowed(self, char):
+        with pytest.raises(ValueError):
+            with HTTPConnectionPool(self.host, self.port) as pool:
+                pool.request("GET" + char, "/")
+
     def test_percent_encode_invalid_target_chars(self):
         with HTTPConnectionPool(self.host, self.port) as pool:
             r = pool.request("GET", "/echo_params?q=\r&k=\n \n")