diff --git a/examples/debugServer.hs b/examples/debugServer.hs
new file mode 100644
--- /dev/null
+++ b/examples/debugServer.hs
@@ -0,0 +1,43 @@
+{-# LANGUAGE OverloadedStrings, PackageImports #-}
+
+import Control.Applicative
+import Control.Monad
+import "monads-tf" Control.Monad.State
+import Control.Concurrent
+import Data.HandleLike
+import System.Environment
+import Network
+import Network.PeyoTLS.Server
+import Network.PeyoTLS.ReadFile
+import "crypto-random" Crypto.Random
+
+import qualified Data.ByteString as BS
+import qualified Data.ByteString.Char8 as BSC
+
+main :: IO ()
+main = do
+	d : _ <- getArgs
+	k <- readKey $ d ++ "/localhost.sample_key"
+	c <- readCertificateChain $ d ++ "/localhost.sample_crt"
+	g0 <- cprgCreate <$> createEntropyPool :: IO SystemRNG
+	soc <- listenOn $ PortNumber 443
+	void . (`runStateT` g0) . forever $ do
+		(h, _, _) <- liftIO $ accept soc
+		g <- StateT $ return . cprgFork
+		liftIO . forkIO . (`run` g) $ do
+			p <- open (DebugHandle h $ Just "medium") ["TLS_RSA_WITH_AES_128_CBC_SHA"] [(k, c)]
+				Nothing
+			doUntil BS.null (hlGetLine p) >>= liftIO . mapM_ BSC.putStrLn
+			hlPut p $ BS.concat [
+				"HTTP/1.1 200 OK\r\n",
+				"Transfer-Encoding: chunked\r\n",
+				"Content-Type: text/plain\r\n\r\n",
+				"5\r\nHello0\r\n\r\n" ]
+			hlClose p
+
+doUntil :: Monad m => (a -> Bool) -> m a -> m [a]
+doUntil p rd = rd >>= \x ->
+	(if p x then return . (: []) else (`liftM` doUntil p rd) . (:)) x
+
+instance ValidateHandle h => ValidateHandle (DebugHandle h) where
+	validate (DebugHandle h _) = validate h
diff --git a/peyotls.cabal b/peyotls.cabal
--- a/peyotls.cabal
+++ b/peyotls.cabal
@@ -2,7 +2,7 @@
 cabal-version:	>= 1.8
 
 name:		peyotls
-version:	0.0.0.12
+version:	0.0.0.13
 stability:	Experimental
 author:		Yoshikuni Jujo <PAF01143@nifty.ne.jp>
 maintainer:	Yoshikuni Jujo <PAF01143@nifty.ne.jp>
@@ -252,6 +252,7 @@
     examples/clcertEcdsaClient.hs
     examples/eccServer.hs
     examples/eccClient.hs
+    examples/debugServer.hs
 
 data-dir: data
 data-files:
@@ -272,7 +273,7 @@
 source-repository	this
     type:	git
     location:	git://github.com/YoshikuniJujo/peyotls.git
-    tag:	peyotls-0.0.0.12
+    tag:	peyotls-0.0.0.13
 
 library
     hs-source-dirs:	src
@@ -297,7 +298,7 @@
         cryptohash == 0.11.*,
         crypto-pubkey == 0.2.*, crypto-pubkey-types == 0.4.*,
         cipher-aes == 0.2.*,
-        bytable == 0.1.*, handle-like == 0.0.0.*
+        bytable == 0.1.*, handle-like == 0.1.*
     ghc-options:	-Wall
     extensions:		PatternGuards, DoAndIfThenElse
 
@@ -305,7 +306,7 @@
     type: exitcode-stdio-1.0
     main-is: testClient.hs
     hs-source-dirs: test
-    build-depends: peyotls, handle-like == 0.0.0.*,
+    build-depends: peyotls, handle-like == 0.1.*,
         base == 4.*, bytestring == 0.10.*, network == 2.4.*, stm == 2.4.*,
         x509 == 1.4.*, x509-store == 1.4.*, crypto-random == 0.0.*
     ghc-options: -Wall
diff --git a/src/Network/PeyoTLS/HandshakeBase.hs b/src/Network/PeyoTLS/HandshakeBase.hs
--- a/src/Network/PeyoTLS/HandshakeBase.hs
+++ b/src/Network/PeyoTLS/HandshakeBase.hs
@@ -78,10 +78,10 @@
 type PeyotlsM = HM.TlsM Handle SystemRNG
 type PeyotlsHandle = HM.TlsHandle Handle SystemRNG
 
-debug :: (HandleLike h, Show a) => a -> HM.HandshakeM h g ()
-debug x = do
+debug :: (HandleLike h, Show a) => DebugLevel h -> a -> HM.HandshakeM h g ()
+debug p x = do
 	h <- gets $ HM.tlsHandle . fst
-	lift . lift . lift . hlDebug h "critical" . BSC.pack . (++ "\n") $ show x
+	lift . lift . lift . hlDebug h p . BSC.pack . (++ "\n") $ show x
 
 readHandshake :: (HandleLike h, CPRG g, HandshakeItem hi) => HM.HandshakeM h g hi
 readHandshake = do
diff --git a/src/Network/PeyoTLS/HandshakeMonad.hs b/src/Network/PeyoTLS/HandshakeMonad.hs
--- a/src/Network/PeyoTLS/HandshakeMonad.hs
+++ b/src/Network/PeyoTLS/HandshakeMonad.hs
@@ -90,7 +90,7 @@
 handshakeValidate cs cc@(X509.CertificateChain c) = gets fst >>= \t -> do
 	modify . first $ const t { TH.names = certNames $ X509.getCertificate $ last c }
 	lift . lift . lift $ validate (TH.tlsHandle t) cs cc
-handshakeValidate _ _ = error "empty certificate chain"
+-- handshakeValidate _ _ = error "empty certificate chain"
 
 setCipherSuite :: HandleLike h => TH.CipherSuite -> HandshakeM h g ()
 setCipherSuite cs = do
diff --git a/src/Network/PeyoTLS/Server.hs b/src/Network/PeyoTLS/Server.hs
--- a/src/Network/PeyoTLS/Server.hs
+++ b/src/Network/PeyoTLS/Server.hs
@@ -10,7 +10,7 @@
 	ValidateHandle(..), CertSecretKey ) where
 
 import Control.Monad (unless, liftM, ap)
-import "monads-tf" Control.Monad.Error (catchError, lift)
+import "monads-tf" Control.Monad.Error (catchError)
 import qualified "monads-tf" Control.Monad.Error as E (throwError)
 import "monads-tf" Control.Monad.Error.Class (strMsg)
 import Data.List (find)
@@ -19,7 +19,6 @@
 import "crypto-random" Crypto.Random (CPRG)
 
 import qualified Data.ByteString as BS
-import qualified Data.ByteString.Char8 as BSC
 import qualified Data.X509 as X509
 import qualified Data.X509.Validation as X509
 import qualified Data.X509.CertificateStore as X509
@@ -87,8 +86,7 @@
 		AES_128_CBC_SHA256 -> return Sha256
 		_ -> E.throwError
 			"TlsServer.open: not implemented bulk encryption type"
-	lift . lift . lift . hlDebug h "critical" . BSC.pack . (++ "\n") . show .
-		RSA.public_size $ RSA.private_pub rsk
+--	debug "medium" . RSA.public_size $ RSA.private_pub rsk
 	mpk <- (\kep -> kep (cr, sr) mcs) $ case ke of
 		RSA -> rsaKeyExchange rsk cv
 		DHE_RSA -> dhKeyExchange ha dh3072Modp rsk
@@ -130,15 +128,16 @@
 clientHello :: (HandleLike h, CPRG g) =>
 	[CipherSuite] -> HandshakeM h g (CipherSuite, BS.ByteString, Version, Bool)
 clientHello cssv = do
-	ClientHello cv cr _sid cscl cms e <- readHandshake
-	debug e
+	ch@(ClientHello cv cr _sid cscl cms e) <- readHandshake
+	debug "medium" ch
+--	debug "medium" e
 	let rn = maybe False (ERenegoInfo "" `elem`) e
-	debug rn
+--	debug "medium" rn
 	chk cv cscl cms >> return (merge cssv cscl, cr, cv, rn)
 	where
 	merge sv cl = case find (`elem` cl) sv of
 		Just cs -> cs; _ -> CipherSuite RSA AES_128_CBC_SHA
-	chk cv css cms
+	chk cv _css cms
 		| cv < version = throwError ALFatal ADProtocolVersion $
 			pmsg ++ "client version should 3.3 or more"
 			{-
diff --git a/src/Network/PeyoTLS/TlsHandle.hs b/src/Network/PeyoTLS/TlsHandle.hs
--- a/src/Network/PeyoTLS/TlsHandle.hs
+++ b/src/Network/PeyoTLS/TlsHandle.hs
@@ -105,6 +105,9 @@
 	e <- read t =<< either (throwError . strMsg) return . B.decode =<< read t 2
 	when (BS.null e) $ throwError "TlsHandle.getWholeWithCt: e is null"
 	p <- decrypt t ct e
+	thlDebug (tlsHandle t) "high" . BSC.pack . (++ ": ") $ show ct
+	thlDebug (tlsHandle t) "high" . BSC.pack . (++  "\n") . show $ BS.head p
+	thlDebug (tlsHandle t) "low" . BSC.pack . (++ "\n") $ show p
 	return (ct, p)
 
 read :: (HandleLike h, CPRG g) => TlsHandle h g -> Int -> TlsM h g BS.ByteString
@@ -230,7 +233,7 @@
 debugCipherSuite :: HandleLike h => TlsHandle h g -> String -> TlsM h g ()
 debugCipherSuite t a = do
 	k <- getKeys $ clientId t
-	thlDebug (tlsHandle t) "moderate" . BSC.pack
+	thlDebug (tlsHandle t) "high" . BSC.pack
 		. (++ (" - VERIFY WITH " ++ a ++ "\n")) . lenSpace 50
 		. show $ kCachedCS k
 	where lenSpace n str = str ++ replicate (n - length str) ' '
diff --git a/test/testClient.hs b/test/testClient.hs
--- a/test/testClient.hs
+++ b/test/testClient.hs
@@ -1,4 +1,4 @@
-{-# LANGUAGE TypeFamilies, PackageImports #-}
+{-# LANGUAGE OverloadedStrings, TypeFamilies, PackageImports #-}
 
 import Control.Applicative
 import Control.Monad
@@ -90,7 +90,9 @@
 					return (False, l, x)
 		if b	then (bs `BS.append`) <$> hlGet h (n - l)
 			else return bs
-	hlDebug _ _ = BS.putStr
+	hlDebug _ dl
+		| dl >= "high" = BS.putStr
+		| otherwise = const $ return ()
 	hlClose _ = return ()
 
 instance ValidateHandle ChanHandle where