From afb7ee6ff4809796a56877efd3ef1bcd50603542 Mon Sep 17 00:00:00 2001
From: amiremohamadi <amiremohamadi@yahoo.com>
Date: Wed, 12 Feb 2020 17:22:08 +0330
Subject: [PATCH 1/4] reject control characters within http method name

---
 Lib/http/client.py                                 | 14 ++++++++++++++
 .../2020-02-12-14-17-39.bpo-39603.Gt3RSg.rst       |  2 ++
 2 files changed, 16 insertions(+)
 create mode 100644 Misc/NEWS.d/next/Security/2020-02-12-14-17-39.bpo-39603.Gt3RSg.rst

diff --git a/Lib/http/client.py b/Lib/http/client.py
index 33a434733f8a46..76550d43208b41 100644
--- a/Lib/http/client.py
+++ b/Lib/http/client.py
@@ -147,6 +147,10 @@
 #  _is_allowed_url_pchars_re = re.compile(r"^[/!$&'()*+,;=:@%a-zA-Z0-9._~-]+$")
 # We are more lenient for assumed real world compatibility purposes.
 
+# These characters are not allowed within HTTP method names
+# to prevent http header injection.
+_contains_disallowed_method_pchar_re = re.compile('[\x00-\x1f]')
+
 # We always set the Content-Length header for these methods because some
 # servers will otherwise respond with a 411
 _METHODS_EXPECTING_BODY = {'PATCH', 'POST', 'PUT'}
@@ -1086,6 +1090,7 @@ def putrequest(self, method, url, skip_host=False,
             raise CannotSendRequest(self.__state)
 
         # Save the method for use later in the response phase
+        self._validate_method(method)
         self._method = method
 
         url = url or '/'
@@ -1175,6 +1180,15 @@ def _encode_request(self, request):
         # ASCII also helps prevent CVE-2019-9740.
         return request.encode('ascii')
 
+    def _validate_method(self, method):
+        """Validate a method name for putrequest."""
+        # prevent http header injection
+        match = _contains_disallowed_method_pchar_re.search(method)
+        if match:
+            raise ValueError(
+                    f"method can't contain control characters. {method!r} "
+                    f"(found at least {match.group()!r})")
+
     def _validate_path(self, url):
         """Validate a url for putrequest."""
         # Prevent CVE-2019-9740.
diff --git a/Misc/NEWS.d/next/Security/2020-02-12-14-17-39.bpo-39603.Gt3RSg.rst b/Misc/NEWS.d/next/Security/2020-02-12-14-17-39.bpo-39603.Gt3RSg.rst
new file mode 100644
index 00000000000000..2fd85da3a42731
--- /dev/null
+++ b/Misc/NEWS.d/next/Security/2020-02-12-14-17-39.bpo-39603.Gt3RSg.rst
@@ -0,0 +1,2 @@
+Prevent http header injection by encoding method parameter in
+http.client.putrequest(...) to ASCII.

From b14bd482de4ccabca8a37863014c38f7db4fd74a Mon Sep 17 00:00:00 2001
From: AMIR <31338382+amiremohamadi@users.noreply.github.com>
Date: Wed, 12 Feb 2020 17:28:19 +0330
Subject: [PATCH 2/4] Update 2020-02-12-14-17-39.bpo-39603.Gt3RSg.rst

---
 .../next/Security/2020-02-12-14-17-39.bpo-39603.Gt3RSg.rst    | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/Misc/NEWS.d/next/Security/2020-02-12-14-17-39.bpo-39603.Gt3RSg.rst b/Misc/NEWS.d/next/Security/2020-02-12-14-17-39.bpo-39603.Gt3RSg.rst
index 2fd85da3a42731..990affc3edd9d8 100644
--- a/Misc/NEWS.d/next/Security/2020-02-12-14-17-39.bpo-39603.Gt3RSg.rst
+++ b/Misc/NEWS.d/next/Security/2020-02-12-14-17-39.bpo-39603.Gt3RSg.rst
@@ -1,2 +1,2 @@
-Prevent http header injection by encoding method parameter in
-http.client.putrequest(...) to ASCII.
+Prevent http header injection by rejecting control characters in
+http.client.putrequest(...).

From 31ae5136bbe2ef614a6ee1c798edb4c2e93bdaa1 Mon Sep 17 00:00:00 2001
From: amiremohamadi <amiremohamadi@yahoo.com>
Date: Wed, 12 Feb 2020 22:54:13 +0330
Subject: [PATCH 3/4] add test for rejecting bad HTTP method names

---
 Lib/test/test_httplib.py | 22 ++++++++++++++++++++++
 1 file changed, 22 insertions(+)

diff --git a/Lib/test/test_httplib.py b/Lib/test/test_httplib.py
index e1aa41421febf4..249c5fafc77e98 100644
--- a/Lib/test/test_httplib.py
+++ b/Lib/test/test_httplib.py
@@ -364,6 +364,28 @@ def test_headers_debuglevel(self):
         self.assertEqual(lines[3], "header: Second: val2")
 
 
+class HttpMethodTests(TestCase):
+    def test_invalid_method_names(self):
+        methods = (
+            'GET\r',
+            'POST\n',
+            'PUT\n\r',
+            'POST\nValue',
+            'POST\nHOST:abc',
+            'GET\nrHost:abc\n',
+            'POST\rRemainder:\r',
+            'GET\rHOST:\n',
+            '\nPUT'
+        )
+
+        for method in methods:
+            with self.assertRaisesRegex(
+                    ValueError, "method can't contain control characters"):
+                conn = client.HTTPConnection('example.com')
+                conn.sock = FakeSocket(None)
+                conn.request(method=method, url="/")
+
+
 class TransferEncodingTest(TestCase):
     expected_body = b"It's just a flesh wound"
 

From 26ae13000de2d616f9e33c77c953db1a938fefc6 Mon Sep 17 00:00:00 2001
From: amiremohamadi <amiremohamadi@yahoo.com>
Date: Sat, 18 Jul 2020 22:35:58 +0430
Subject: [PATCH 4/4] fix comment position

---
 Lib/http/client.py | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/Lib/http/client.py b/Lib/http/client.py
index 76550d43208b41..c708ec2218c426 100644
--- a/Lib/http/client.py
+++ b/Lib/http/client.py
@@ -1089,8 +1089,9 @@ def putrequest(self, method, url, skip_host=False,
         else:
             raise CannotSendRequest(self.__state)
 
-        # Save the method for use later in the response phase
         self._validate_method(method)
+
+        # Save the method for use later in the response phase
         self._method = method
 
         url = url or '/'