From ca207acb4fdea344bb3a775d44aa0d9f59ad31a1 Mon Sep 17 00:00:00 2001
From: Toshio Kuratomi <toshio@fedoraproject.org>
Date: Mon, 15 Jul 2013 10:58:20 -0700
Subject: [PATCH] fix for http://bugs.python.org/issue17980 in code backported
 from the python3 stdlib

---
 pip/backwardcompat/ssl_match_hostname.py | 10 +++++++++-
 1 file changed, 9 insertions(+), 1 deletion(-)

diff --git a/pip/backwardcompat/ssl_match_hostname.py b/pip/backwardcompat/ssl_match_hostname.py
index 5707649..a6fadf4 100644
--- a/pip/backwardcompat/ssl_match_hostname.py
+++ b/pip/backwardcompat/ssl_match_hostname.py
@@ -7,9 +7,17 @@ __version__ = '3.2a3'
 class CertificateError(ValueError):
     pass
 
-def _dnsname_to_pat(dn):
+def _dnsname_to_pat(dn, max_wildcards=1):
     pats = []
     for frag in dn.split(r'.'):
+        if frag.count('*') > max_wildcards:
+            # Issue #17980: avoid denials of service by refusing more
+            # than one wildcard per fragment.  A survery of established
+            # policy among SSL implementations showed it to be a
+            # reasonable choice.
+            raise CertificateError(
+                "too many wildcards in certificate DNS name: " + repr(dn))
+
         if frag == '*':
             # When '*' is a fragment by itself, it matches a non-empty dotless
             # fragment.
-- 
1.7.11.7