Issue #15225: improve error message when hmac is passed a wrong key type.
Patch by Marc Abramowitz.
diff --git a/Lib/hmac.py b/Lib/hmac.py
index 9c08023..4297a71 100644
--- a/Lib/hmac.py
+++ b/Lib/hmac.py
@@ -35,7 +35,7 @@
         """
 
         if not isinstance(key, bytes):
-            raise TypeError("expected bytes, but got %r" % type(key).__name__)
+            raise TypeError("key: expected bytes, but got %r" % type(key).__name__)
 
         if digestmod is None:
             import hashlib
diff --git a/Lib/test/test_hmac.py b/Lib/test/test_hmac.py
index 11cacb4..4ca7cec 100644
--- a/Lib/test/test_hmac.py
+++ b/Lib/test/test_hmac.py
@@ -234,6 +234,18 @@
         except:
             self.fail("Standard constructor call raised exception.")
 
+    def test_with_str_key(self):
+        # Pass a key of type str, which is an error, because it expects a key
+        # of type bytes
+        with self.assertRaises(TypeError):
+            h = hmac.HMAC("key")
+
+    def test_dot_new_with_str_key(self):
+        # Pass a key of type str, which is an error, because it expects a key
+        # of type bytes
+        with self.assertRaises(TypeError):
+            h = hmac.new("key")
+
     def test_withtext(self):
         # Constructor call with text.
         try:
diff --git a/Misc/ACKS b/Misc/ACKS
index e2a4f9b..9af9dcd 100644
--- a/Misc/ACKS
+++ b/Misc/ACKS
@@ -13,6 +13,7 @@
 
 Rajiv Abraham
 David Abrahams
+Marc Abramowitz
 Ron Adam
 Ali Afshar
 Jim Ahlstrom