diff --git a/OpenSSL/Digest.hs b/OpenSSL/Digest.hs
--- a/OpenSSL/Digest.hs
+++ b/OpenSSL/Digest.hs
@@ -1,9 +1,8 @@
-{-# INCLUDE <openssl/evp.h> #-}
-{-# LANGUAGE ForeignFunctionInterface, GeneralizedNewtypeDeriving, DeriveDataTypeable #-}
+{-# LANGUAGE ForeignFunctionInterface #-}
 
 {- |
    Module      :  OpenSSL.Digest
-   Copyright   :  (c) 2009 by Peter Simons
+   Copyright   :  (c) 2010 by Peter Simons
    License     :  BSD3
 
    Maintainer  :  simons@cryp.to
@@ -44,7 +43,6 @@
 import Foreign.C
 import Control.Monad.State
 import Numeric ( showHex )
-import Data.Typeable
 
 -- * High-level API
 
@@ -77,7 +75,6 @@
 -- |The internal EVP context.
 
 newtype DigestState = DST (Ptr OpaqueContext)
-  deriving (Typeable)
 
 -- |Run an 'IO' computation with an initialized
 -- 'DigestState'. All resources will be freed when the
diff --git a/OpenSSL/Digest/ByteString.hs b/OpenSSL/Digest/ByteString.hs
new file mode 100644
--- /dev/null
+++ b/OpenSSL/Digest/ByteString.hs
@@ -0,0 +1,44 @@
+{- |
+   Module      :  OpenSSL.Digest.ByteString
+   Copyright   :  (c) 2010 by Peter Simons
+   License     :  BSD3
+
+   Maintainer  :  simons@cryp.to
+   Stability   :  provisional
+   Portability :  portable
+
+   Wrappers for "OpenSSL.Digest" that supports 'ByteString'.
+ -}
+
+module OpenSSL.Digest.ByteString where
+
+import OpenSSL.Digest hiding ( update )
+import Control.Monad.State ( evalStateT, lift, get )
+import Foreign.Ptr ( castPtr )
+import Data.Word ( Word8 )
+import Data.ByteString ( ByteString )
+import Data.ByteString.Unsafe ( unsafeUseAsCStringLen )
+
+-- |A convenience wrapper which computes the given digest type of a
+-- 'ByteString'. Unlike the monadic interface, this function does not
+-- allow the computation to be restarted.
+
+digest :: MessageDigest -> ByteString -> IO [Word8]
+digest mdType xs =
+  mkDigest mdType $ evalStateT (update xs >> final)
+
+-- |Update the internal state with a block of data.
+
+update :: ByteString -> Digest Int
+update bs = do
+    DST ctx <- get
+    l <- lift $
+      unsafeUseAsCStringLen bs $ \(ptr, len) ->
+        digestUpdate ctx (castPtr ptr) (fromIntegral len)
+    return (fromEnum l)
+
+-- ----- Configure Emacs -----
+--
+-- Local Variables: ***
+-- haskell-program-name: "ghci -ignore-package hopenssl -Wall -lcrypto" ***
+-- End: ***
diff --git a/OpenSSL/Digest/ByteString/Lazy.hs b/OpenSSL/Digest/ByteString/Lazy.hs
new file mode 100644
--- /dev/null
+++ b/OpenSSL/Digest/ByteString/Lazy.hs
@@ -0,0 +1,38 @@
+{- |
+   Module      :  OpenSSL.Digest.ByteString.Lazy
+   Copyright   :  (c) 2010 by Peter Simons
+   License     :  BSD3
+
+   Maintainer  :  simons@cryp.to
+   Stability   :  provisional
+   Portability :  portable
+
+   Wrappers for "OpenSSL.Digest" that supports lazy 'ByteString'.
+ -}
+
+module OpenSSL.Digest.ByteString.Lazy where
+
+import OpenSSL.Digest hiding ( update )
+import Data.Word ( Word8 )
+import Control.Monad.State ( evalStateT )
+import qualified OpenSSL.Digest.ByteString as BS ( update )
+import Data.ByteString.Lazy ( ByteString, toChunks )
+
+-- |A convenience wrapper which computes the given digest type of a
+-- 'ByteString'. Unlike the monadic interface, this function does not
+-- allow the computation to be restarted.
+
+digest :: MessageDigest -> ByteString -> IO [Word8]
+digest mdType xs =
+  mkDigest mdType $ evalStateT (update xs >> final)
+
+-- |Update the internal state with a block of data.
+
+update :: ByteString -> Digest Int
+update = fmap sum . mapM BS.update . toChunks
+
+-- ----- Configure Emacs -----
+--
+-- Local Variables: ***
+-- haskell-program-name: "ghci -ignore-package hopenssl -Wall -lcrypto" ***
+-- End: ***
diff --git a/hopenssl.cabal b/hopenssl.cabal
--- a/hopenssl.cabal
+++ b/hopenssl.cabal
@@ -1,9 +1,9 @@
 Name:                   hopenssl
-Version:                1.3
+Version:                1.4
 Copyright:              (c) 2004-2010 Peter Simons
 License:                BSD3
 License-File:           LICENSE
-Author:                 Peter Simons <simons@cryp.to>
+Author:                 Peter Simons <simons@cryp.to>, Jesper Louis Andersen <jesper.louis.andersen@gmail.com>
 Maintainer:             Peter Simons <simons@cryp.to>
 Homepage:               http://gitorious.org/hopenssl
 Category:               Foreign, Cryptography
@@ -17,19 +17,14 @@
 Build-Type:             Simple
 Tested-With:            GHC == 6.12.1
 
-Source-Repository this
-  Tag:                  v1.3
-  Type:                 git
-  Location:             git://gitorious.org/hopenssl/mainline.git
-
 Source-Repository head
   Type:                 git
   Location:             git://gitorious.org/hopenssl/mainline.git
 
 Library
-  Build-Depends:        base >= 3 && < 5, mtl
+  Build-Depends:        base >= 3 && < 5, mtl, bytestring
   Extensions:           ForeignFunctionInterface
   Extra-Libraries:      crypto
   Includes:             "openssl/evp.h"
-  Exposed-Modules:      OpenSSL.Digest
+  Exposed-Modules:      OpenSSL.Digest, OpenSSL.Digest.ByteString, OpenSSL.Digest.ByteString.Lazy
   Ghc-Options:          -Wall