1 files changed, 45 insertions, 5 deletions
diff --git a/requests/packages/urllib3/util.py b/requests/packages/urllib3/util.py
index b827bc4..544f9ed 100644
--- a/requests/packages/urllib3/util.py
+++ b/requests/packages/urllib3/util.py
@@ -1,5 +1,5 @@
 # urllib3/util.py
-# Copyright 2008-2012 Andrey Petrov and contributors (see CONTRIBUTORS.txt)
+# Copyright 2008-2013 Andrey Petrov and contributors (see CONTRIBUTORS.txt)
 #
 # This module is part of urllib3 and is released under
 # the MIT License: http://www.opensource.org/licenses/mit-license.php
@@ -8,6 +8,8 @@
 from base64 import b64encode
 from collections import namedtuple
 from socket import error as SocketError
+from hashlib import md5, sha1
+from binascii import hexlify, unhexlify
 
 try:
     from select import poll, POLLIN
@@ -23,7 +25,7 @@ try:  # Test for SSL features
     HAS_SNI = False
 
     import ssl
-    from ssl import wrap_socket, CERT_NONE, SSLError, PROTOCOL_SSLv23
+    from ssl import wrap_socket, CERT_NONE, PROTOCOL_SSLv23
     from ssl import SSLContext  # Modern SSL?
     from ssl import HAS_SNI  # Has SNI?
 except ImportError:
@@ -31,7 +33,7 @@ except ImportError:
 
 
 from .packages import six
-from .exceptions import LocationParseError
+from .exceptions import LocationParseError, SSLError
 
 
 class Url(namedtuple('Url', ['scheme', 'auth', 'host', 'port', 'path', 'query', 'fragment'])):
@@ -232,7 +234,7 @@ def make_headers(keep_alive=None, accept_encoding=None, user_agent=None,
     return headers
 
 
-def is_connection_dropped(conn):
+def is_connection_dropped(conn):  # Platform-specific
     """
     Returns True if the connection is dropped and should be closed.
 
@@ -246,7 +248,7 @@ def is_connection_dropped(conn):
     if not sock: # Platform-specific: AppEngine
         return False
 
-    if not poll: # Platform-specific
+    if not poll:
         if not select: # Platform-specific: AppEngine
             return False
 
@@ -302,6 +304,44 @@ def resolve_ssl_version(candidate):
 
     return candidate
 
+
+def assert_fingerprint(cert, fingerprint):
+    """
+    Checks if given fingerprint matches the supplied certificate.
+
+    :param cert:
+        Certificate as bytes object.
+    :param fingerprint:
+        Fingerprint as string of hexdigits, can be interspersed by colons.
+    """
+
+    # Maps the length of a digest to a possible hash function producing
+    # this digest.
+    hashfunc_map = {
+        16: md5,
+        20: sha1
+    }
+
+    fingerprint = fingerprint.replace(':', '').lower()
+
+    digest_length, rest = divmod(len(fingerprint), 2)
+
+    if rest or digest_length not in hashfunc_map:
+        raise SSLError('Fingerprint is of invalid length.')
+
+    # We need encode() here for py32; works on py2 and p33.
+    fingerprint_bytes = unhexlify(fingerprint.encode())
+
+    hashfunc = hashfunc_map[digest_length]
+
+    cert_digest = hashfunc(cert).digest()
+
+    if not cert_digest == fingerprint_bytes:
+        raise SSLError('Fingerprints did not match. Expected "{0}", got "{1}".'
+                       .format(hexlify(fingerprint_bytes),
+                               hexlify(cert_digest)))
+
+
 if SSLContext is not None:  # Python 3.2+
     def ssl_wrap_socket(sock, keyfile=None, certfile=None, cert_reqs=None,
                         ca_certs=None, server_hostname=None,