diff --git a/happstack-server.cabal b/happstack-server.cabal
--- a/happstack-server.cabal
+++ b/happstack-server.cabal
@@ -1,5 +1,5 @@
 Name:                happstack-server
-Version:             7.5.3
+Version:             7.5.4
 Synopsis:            Web related tools and services.
 Description:         Happstack Server provides an HTTP server and a rich set of functions for routing requests, handling query parameters, generating responses, working with cookies, serving files, and more. For in-depth documentation see the Happstack Crash Course <http://happstack.com/docs/crashcourse/index.html>
 License:             BSD3
diff --git a/src/Happstack/Server/Auth.hs b/src/Happstack/Server/Auth.hs
--- a/src/Happstack/Server/Auth.hs
+++ b/src/Happstack/Server/Auth.hs
@@ -25,26 +25,56 @@
    -> M.Map String String -- ^ the username password map
    -> m a -- ^ the part to guard
    -> m a
-basicAuth realmName authMap xs = basicAuthImpl `mplus` xs
+basicAuth realmName authMap = basicAuthBy (validLoginPlaintext authMap) realmName
+
+
+-- | Generalized version of 'basicAuth'.
+--
+-- The function that checks the username password combination must be
+-- supplied as first argument.
+--
+-- example:
+--
+-- > main = simpleHTTP nullConf $
+-- >  msum [ basicAuth' (validLoginPlaintext (fromList [("happstack","rocks")])) "127.0.0.1" $ ok "You are in the secret club"
+-- >       , ok "You are not in the secret club."
+-- >       ]
+--
+basicAuthBy :: (Happstack m) =>
+   (B.ByteString -> B.ByteString -> Bool) -- ^ function that returns true if the name password combination is valid
+   -> String -- ^ the realm name
+   -> m a -- ^ the part to guard
+   -> m a
+basicAuthBy validLogin realmName xs = basicAuthImpl `mplus` xs
   where
     basicAuthImpl = do
         aHeader <- getHeaderM "authorization"
         case aHeader of
             Nothing -> err
-            Just x -> 
-                do r <- parseHeader x 
-                   case r of
-                     (name, ':':password) | validLogin name password -> mzero
-                                          | otherwise -> err
-                     _  -> err
-    validLogin name password = M.lookup name authMap == Just password
-    parseHeader h = 
+            Just x ->
+                do (name, password) <- parseHeader x
+                   if B.length password > 0
+                      && B.head password == ':'
+                      && validLogin name (B.tail password)
+                     then mzero
+                     else err
+    parseHeader h =
       case Base64.decode . B.drop 6 $ h of
         (Left _)   -> err
-        (Right bs) -> return (break (':'==) (B.unpack bs))
+        (Right bs) -> return (B.break (':'==) bs)
     headerName  = "WWW-Authenticate"
     headerValue = "Basic realm=\"" ++ realmName ++ "\""
     err :: (Happstack m) => m a
     err = escape $ do
             setHeaderM headerName headerValue
             unauthorized $ toResponse "Not authorized"
+
+
+-- | Function that looks up the plain text password for username in a
+-- Map and returns True if it matches with the given password.
+validLoginPlaintext ::
+  M.Map String String -- ^ the username password map
+  -> B.ByteString -- ^ the username
+  -> B.ByteString -- ^ the password
+  -> Bool
+validLoginPlaintext authMap name password = M.lookup (B.unpack name) authMap == Just (B.unpack password)