4 files changed, 71 insertions, 18 deletions
diff --git a/urllib3/util/connection.py b/urllib3/util/connection.py
index 859aec6..9ed5a64 100644
--- a/urllib3/util/connection.py
+++ b/urllib3/util/connection.py
@@ -60,6 +60,8 @@ def create_connection(address, timeout=socket._GLOBAL_DEFAULT_TIMEOUT,
     """
 
     host, port = address
+    if host.startswith('['):
+        host = host.strip('[]')
     err = None
     for res in socket.getaddrinfo(host, port, 0, socket.SOCK_STREAM):
         af, socktype, proto, canonname, sa = res
diff --git a/urllib3/util/response.py b/urllib3/util/response.py
index 45fff55..767ee15 100644
--- a/urllib3/util/response.py
+++ b/urllib3/util/response.py
@@ -1,3 +1,11 @@
+try:
+    import http.client as httplib
+except ImportError:
+    import httplib
+
+from ..exceptions import HeaderParsingError
+
+
 def is_fp_closed(obj):
     """
     Checks whether a given file-like object is closed.
@@ -20,3 +28,49 @@ def is_fp_closed(obj):
         pass
 
     raise ValueError("Unable to determine whether fp is closed.")
+
+
+def assert_header_parsing(headers):
+    """
+    Asserts whether all headers have been successfully parsed.
+    Extracts encountered errors from the result of parsing headers.
+
+    Only works on Python 3.
+
+    :param headers: Headers to verify.
+    :type headers: `httplib.HTTPMessage`.
+
+    :raises urllib3.exceptions.HeaderParsingError:
+        If parsing errors are found.
+    """
+
+    # This will fail silently if we pass in the wrong kind of parameter.
+    # To make debugging easier add an explicit check.
+    if not isinstance(headers, httplib.HTTPMessage):
+        raise TypeError('expected httplib.Message, got {}.'.format(
+            type(headers)))
+
+    defects = getattr(headers, 'defects', None)
+    get_payload = getattr(headers, 'get_payload', None)
+
+    unparsed_data = None
+    if get_payload:  # Platform-specific: Python 3.
+        unparsed_data = get_payload()
+
+    if defects or unparsed_data:
+        raise HeaderParsingError(defects=defects, unparsed_data=unparsed_data)
+
+
+def is_response_to_head(response):
+    """
+    Checks, wether a the request of a response has been a HEAD-request.
+    Handles the quirks of AppEngine.
+
+    :param conn:
+    :type conn: :class:`httplib.HTTPResponse`
+    """
+    # FIXME: Can we do this somehow without accessing private httplib _method?
+    method = response._method
+    if isinstance(method, int):  # Platform-specific: Appengine
+        return method == 3
+    return method.upper() == 'HEAD'
diff --git a/urllib3/util/retry.py b/urllib3/util/retry.py
index 7e0959d..1fb1f23 100644
--- a/urllib3/util/retry.py
+++ b/urllib3/util/retry.py
@@ -94,7 +94,7 @@ class Retry(object):
 
         seconds. If the backoff_factor is 0.1, then :func:`.sleep` will sleep
         for [0.1s, 0.2s, 0.4s, ...] between retries. It will never be longer
-        than :attr:`Retry.MAX_BACKOFF`.
+        than :attr:`Retry.BACKOFF_MAX`.
 
         By default, backoff is disabled (set to 0).
 
diff --git a/urllib3/util/ssl_.py b/urllib3/util/ssl_.py
index b846d42..311378b 100644
--- a/urllib3/util/ssl_.py
+++ b/urllib3/util/ssl_.py
@@ -8,6 +8,13 @@ SSLContext = None
 HAS_SNI = False
 create_default_context = None
 
+# Maps the length of a digest to a possible hash function producing this digest
+HASHFUNC_MAP = {
+    32: md5,
+    40: sha1,
+    64: sha256,
+}
+
 import errno
 import warnings
 
@@ -112,31 +119,21 @@ def assert_fingerprint(cert, 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,
-        32: sha256,
-    }
-
     fingerprint = fingerprint.replace(':', '').lower()
-    digest_length, odd = divmod(len(fingerprint), 2)
-
-    if odd or digest_length not in hashfunc_map:
-        raise SSLError('Fingerprint is of invalid length.')
+    digest_length = len(fingerprint)
+    hashfunc = HASHFUNC_MAP.get(digest_length)
+    if not hashfunc:
+        raise SSLError(
+            'Fingerprint of invalid length: {0}'.format(fingerprint))
 
     # 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:
+    if cert_digest != fingerprint_bytes:
         raise SSLError('Fingerprints did not match. Expected "{0}", got "{1}".'
-                       .format(hexlify(fingerprint_bytes),
-                               hexlify(cert_digest)))
+                       .format(fingerprint, hexlify(cert_digest)))
 
 
 def resolve_cert_reqs(candidate):