diff -r b9b521efeba3 Doc/library/hmac.rst
--- a/Doc/library/hmac.rst	Sat May 18 17:56:42 2013 +0200
+++ b/Doc/library/hmac.rst	Mon Jun 17 22:16:45 2013 +0200
@@ -16,18 +16,18 @@
 
 .. function:: new(key, msg=None, digestmod=None)
 
-   Return a new hmac object.  *key* is a bytes object giving the secret key.  If
-   *msg* is present, the method call ``update(msg)`` is made.  *digestmod* is
-   the digest constructor or module for the HMAC object to use. It defaults to
-   the :func:`hashlib.md5` constructor.
+   Return a new hmac object.  *key* is a bytes or bytearray object giving the
+   secret key.  If *msg* is present, the method call ``update(msg)`` is made.
+   *digestmod* is the digest constructor or module for the HMAC object to use.
+   It defaults to the :func:`hashlib.md5` constructor.
 
 
 An HMAC object has the following methods:
 
 .. method:: HMAC.update(msg)
 
-   Update the hmac object with the bytes object *msg*.  Repeated calls are
-   equivalent to a single call with the concatenation of all the arguments:
+   Update the hmac object with *msg*.  Repeated calls are equivalent to a
+   single call with the concatenation of all the arguments:
    ``m.update(a); m.update(b)`` is equivalent to ``m.update(a + b)``.
 
 
diff -r b9b521efeba3 Lib/hmac.py
--- a/Lib/hmac.py	Sat May 18 17:56:42 2013 +0200
+++ b/Lib/hmac.py	Mon Jun 17 22:16:45 2013 +0200
@@ -29,11 +29,11 @@
                    A hashlib constructor returning a new hash object.
                    Defaults to hashlib.md5.
 
-        Note: key and msg must be bytes objects.
+        Note: key must be a bytes or bytearray object.
         """
 
-        if not isinstance(key, bytes):
-            raise TypeError("expected bytes, but got %r" % type(key).__name__)
+        if not isinstance(key, (bytes, bytearray)):
+            raise TypeError("expected bytes or bytearray, but got %r" % type(key).__name__)
 
         if digestmod is None:
             import hashlib
@@ -73,8 +73,6 @@
     def update(self, msg):
         """Update this hashing object with the string msg.
         """
-        if not isinstance(msg, bytes):
-            raise TypeError("expected bytes, but got %r" % type(msg).__name__)
         self.inner.update(msg)
 
     def copy(self):