gnutls (empty) → 0.1
raw patch · 6 files changed
+1313/−0 lines, 6 filesdep +basedep +bytestringdep +monads-tfsetup-changed
Dependencies added: base, bytestring, monads-tf, transformers
Files
- Network/Protocol/TLS/GNU.hs +251/−0
- Network/Protocol/TLS/GNU/ErrorT.hs +66/−0
- Network/Protocol/TLS/GNU/Foreign.hs +283/−0
- Setup.hs +2/−0
- gnutls.cabal +37/−0
- license.txt +674/−0
+ Network/Protocol/TLS/GNU.hs view
@@ -0,0 +1,251 @@+-- Copyright (C) 2010 John Millikin <jmillikin@gmail.com>+-- +-- This program is free software: you can redistribute it and/or modify+-- it under the terms of the GNU General Public License as published by+-- the Free Software Foundation, either version 3 of the License, or+-- any later version.+-- +-- This program is distributed in the hope that it will be useful,+-- but WITHOUT ANY WARRANTY; without even the implied warranty of+-- MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the+-- GNU General Public License for more details.+-- +-- You should have received a copy of the GNU General Public License+-- along with this program. If not, see <http://www.gnu.org/licenses/>.++{-# LANGUAGE TypeFamilies #-}+module Network.Protocol.TLS.GNU+ ( TLS+ , Session+ , Error (..)+ + , runTLS+ , runClient+ , getSession+ , handshake+ , putBytes+ , getBytes+ , checkPending+ + -- * Settings+ , Transport (..)+ , handleTransport+ + , Credentials+ , setCredentials+ , certificateCredentials+ + , Prioritised+ , setPriority+ , CertificateType (..)+ ) where+import Control.Monad (when, foldM, foldM_)+import Control.Monad.Trans (MonadIO, liftIO)+import qualified Control.Monad.Error as E+import qualified Control.Monad.Reader as R+import qualified Control.Concurrent.MVar as M+import qualified Data.ByteString as B+import qualified Data.ByteString.Unsafe as B+import qualified Data.ByteString.Lazy as BL+import qualified System.IO as IO+import qualified Foreign as F+import qualified Foreign.C as F+import qualified Network.Protocol.TLS.GNU.Foreign as F+import Foreign.Concurrent as FC+import Network.Protocol.TLS.GNU.ErrorT+import System.IO.Unsafe (unsafePerformIO)++data Error = Error Integer+ deriving (Show)++globalInitMVar :: M.MVar ()+{-# NOINLINE globalInitMVar #-}+globalInitMVar = unsafePerformIO $ M.newMVar ()++newtype GlobalState = GlobalState (F.ForeignPtr ())++globalInit :: ErrorT Error IO GlobalState+globalInit = do+ let init = M.withMVar globalInitMVar $ \_ -> F.gnutls_global_init+ let deinit = M.withMVar globalInitMVar $ \_ -> F.gnutls_global_deinit+ F.ReturnCode rc <- liftIO $ init+ when (rc < 0) $ E.throwError $ mapError rc+ fp <- liftIO $ FC.newForeignPtr F.nullPtr deinit+ return $ GlobalState fp++data Session = Session+ { sessionPtr :: F.ForeignPtr F.Session+ , sessionGlobalState :: GlobalState+ }++newtype TLS a = TLS { unTLS :: ErrorT Error (R.ReaderT Session IO) a }++instance Functor TLS where+ fmap f = TLS . fmap f . unTLS++instance Monad TLS where+ return = TLS . return+ m >>= f = TLS $ unTLS m >>= unTLS . f++instance MonadIO TLS where+ liftIO = TLS . liftIO++instance E.MonadError TLS where+ type E.ErrorType TLS = Error+ throwError = TLS . E.throwError+ catchError m h = TLS $ E.catchError (unTLS m) (unTLS . h)++runTLS :: Session -> TLS a -> IO (Either Error a)+runTLS s tls = R.runReaderT (runErrorT (unTLS tls)) s++runClient :: Transport -> TLS a -> IO (Either Error a)+runClient transport tls = do+ eitherSession <- newSession transport (F.ConnectionEnd 2)+ case eitherSession of+ Left err -> return (Left err)+ Right session -> runTLS session tls++newSession :: Transport -> F.ConnectionEnd -> IO (Either Error Session)+newSession transport end = F.alloca $ \sPtr -> runErrorT $ do+ global <- globalInit+ F.ReturnCode rc <- liftIO $ F.gnutls_init sPtr end+ when (rc < 0) $ E.throwError $ mapError rc+ liftIO $ do+ ptr <- F.peek sPtr+ let session = F.Session ptr+ push <- F.wrapTransportFunc (pushImpl transport)+ pull <- F.wrapTransportFunc (pullImpl transport)+ F.gnutls_transport_set_push_function session push+ F.gnutls_transport_set_pull_function session pull+ F.gnutls_set_default_priority session+ fp <- FC.newForeignPtr ptr $ do+ F.gnutls_deinit session+ F.freeHaskellFunPtr push+ F.freeHaskellFunPtr pull+ return $ Session fp global++getSession :: TLS Session+getSession = TLS R.ask++handshake :: TLS ()+handshake = withSession F.gnutls_handshake >>= checkRC++rehandshake :: TLS ()+rehandshake = withSession F.gnutls_rehandshake >>= checkRC++putBytes :: BL.ByteString -> TLS ()+putBytes = putChunks . BL.toChunks where+ putChunks chunks = do+ maybeErr <- withSession $ \s -> foldM (putChunk s) Nothing chunks+ case maybeErr of+ Nothing -> return ()+ Just err -> E.throwError $ mapError $ fromIntegral err+ + putChunk s Nothing chunk = B.unsafeUseAsCStringLen chunk $ uncurry loop where+ loop ptr len = do+ let len' = fromIntegral len+ sent <- F.gnutls_record_send s ptr len'+ let sent' = fromIntegral sent+ case len - sent' of+ 0 -> return Nothing+ x | x > 0 -> loop (F.plusPtr ptr sent') x+ | otherwise -> return $ Just x+ + putChunk _ err _ = return err++getBytes :: Integer -> TLS BL.ByteString+getBytes count = do+ (bytes, len) <- withSession $ \s ->+ F.allocaBytes (fromInteger count) $ \ptr -> do+ len <- F.gnutls_record_recv s ptr (fromInteger count)+ bytes <- if len >= 0+ then do+ chunk <- B.packCStringLen (ptr, fromIntegral len)+ return $ Just $ BL.fromChunks [chunk]+ else return Nothing+ return (bytes, len)+ + case bytes of+ Just bytes -> return bytes+ Nothing -> E.throwError $ mapError $ fromIntegral len++checkPending :: TLS Integer+checkPending = withSession $ \s -> do+ pending <- F.gnutls_record_check_pending s+ return $ toInteger pending++data Transport = Transport+ { transportPush :: BL.ByteString -> IO ()+ , transportPull :: Integer -> IO BL.ByteString+ }++pullImpl :: Transport -> F.TransportFunc+pullImpl t _ buf bufSize = do+ bytes <- transportPull t $ toInteger bufSize+ let loop ptr chunk =+ B.unsafeUseAsCStringLen chunk $ \(cstr, len) -> do+ F.copyArray (F.castPtr ptr) cstr len+ return $ F.plusPtr ptr len+ foldM_ loop buf $ BL.toChunks bytes+ return $ fromIntegral $ BL.length bytes++pushImpl :: Transport -> F.TransportFunc+pushImpl t _ buf bufSize = do+ let buf' = F.castPtr buf+ bytes <- B.unsafePackCStringLen (buf', fromIntegral bufSize)+ transportPush t $ BL.fromChunks [bytes]+ return bufSize++handleTransport :: IO.Handle -> Transport+handleTransport h = Transport (BL.hPut h) (BL.hGet h . fromInteger)++data Credentials = Credentials F.CredentialsType (F.ForeignPtr F.Credentials)++setCredentials :: Credentials -> TLS ()+setCredentials (Credentials ctype fp) = do+ rc <- withSession $ \s ->+ F.withForeignPtr fp $ \ptr -> do+ F.gnutls_credentials_set s ctype ptr+ checkRC rc++certificateCredentials :: TLS Credentials+certificateCredentials = do+ (rc, ptr) <- liftIO $ F.alloca $ \ptr -> do+ rc <- F.gnutls_certificate_allocate_credentials ptr+ ptr <- if F.unRC rc < 0+ then return F.nullPtr+ else F.peek ptr+ return (rc, ptr)+ checkRC rc+ fp <- liftIO $ F.newForeignPtr F.gnutls_certificate_free_credentials_funptr ptr+ return $ Credentials (F.CredentialsType 1) fp++class Prioritised a where+ priorityInt :: a -> F.CInt+ priorityProc :: a -> F.Session -> F.Ptr F.CInt -> IO F.ReturnCode++data CertificateType = X509 | OpenPGP+ deriving (Show)++instance Prioritised CertificateType where+ priorityProc = const F.gnutls_certificate_type_set_priority+ priorityInt x = case x of+ X509 -> 1+ OpenPGP -> 2++setPriority :: Prioritised a => [a] -> TLS ()+setPriority xs = do+ let fake = head $ [undefined] ++ xs+ rc <- withSession $ F.withArray0 0 (map priorityInt xs) . priorityProc fake+ checkRC rc++withSession :: (F.Session -> IO a) -> TLS a+withSession io = do+ s <- getSession+ liftIO $ F.withForeignPtr (sessionPtr s) $ io . F.Session++checkRC :: F.ReturnCode -> TLS ()+checkRC (F.ReturnCode x) = when (x < 0) $ E.throwError $ mapError x++mapError :: F.CInt -> Error+mapError = Error . toInteger
+ Network/Protocol/TLS/GNU/ErrorT.hs view
@@ -0,0 +1,66 @@+-- Copyright (C) 2010 John Millikin <jmillikin@gmail.com>+-- +-- This program is free software: you can redistribute it and/or modify+-- it under the terms of the GNU General Public License as published by+-- the Free Software Foundation, either version 3 of the License, or+-- any later version.+-- +-- This program is distributed in the hope that it will be useful,+-- but WITHOUT ANY WARRANTY; without even the implied warranty of+-- MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the+-- GNU General Public License for more details.+-- +-- You should have received a copy of the GNU General Public License+-- along with this program. If not, see <http://www.gnu.org/licenses/>.++{-# LANGUAGE TypeFamilies #-}+module Network.Protocol.TLS.GNU.ErrorT+ ( ErrorT (..)+ , mapErrorT+ ) where++import Control.Monad (liftM)+import Control.Monad.Trans (MonadIO, liftIO)+import Control.Monad.Trans.Class (MonadTrans, lift)+import qualified Control.Monad.Error as E+import qualified Control.Monad.Reader as R++-- A custom version of ErrorT, without the 'Error' class restriction.++newtype ErrorT e m a = ErrorT { runErrorT :: m (Either e a) }++instance Functor m => Functor (ErrorT e m) where+ fmap f = ErrorT . fmap (fmap f) . runErrorT++instance Monad m => Monad (ErrorT e m) where+ return = ErrorT . return . Right+ (>>=) m k = ErrorT $ do+ x <- runErrorT m+ case x of+ Left l -> return $ Left l+ Right r -> runErrorT $ k r++instance Monad m => E.MonadError (ErrorT e m) where+ type E.ErrorType (ErrorT e m) = e+ throwError = ErrorT . return . Left+ catchError m h = ErrorT $ do+ x <- runErrorT m+ case x of+ Left l -> runErrorT $ h l+ Right r -> return $ Right r++instance MonadTrans (ErrorT e) where+ lift = ErrorT . liftM Right++instance R.MonadReader m => R.MonadReader (ErrorT e m) where+ type R.EnvType (ErrorT e m) = R.EnvType m+ ask = lift R.ask+ local = mapErrorT . R.local++instance MonadIO m => MonadIO (ErrorT e m) where+ liftIO = lift . liftIO++mapErrorT :: (m (Either e a) -> n (Either e' b))+ -> ErrorT e m a+ -> ErrorT e' n b+mapErrorT f m = ErrorT $ f (runErrorT m)
+ Network/Protocol/TLS/GNU/Foreign.hs view
@@ -0,0 +1,283 @@+-- Copyright (C) 2010 John Millikin <jmillikin@gmail.com>+-- +-- This program is free software: you can redistribute it and/or modify+-- it under the terms of the GNU General Public License as published by+-- the Free Software Foundation, either version 3 of the License, or+-- any later version.+-- +-- This program is distributed in the hope that it will be useful,+-- but WITHOUT ANY WARRANTY; without even the implied warranty of+-- MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the+-- GNU General Public License for more details.+-- +-- You should have received a copy of the GNU General Public License+-- along with this program. If not, see <http://www.gnu.org/licenses/>.++{-# LANGUAGE ForeignFunctionInterface #-}+module Network.Protocol.TLS.GNU.Foreign where+import Foreign+import Foreign.C++-- Type aliases {{{++newtype ReturnCode = ReturnCode { unRC :: CInt }+ deriving (Show, Eq)++newtype CipherAlgorithm = CipherAlgorithm CInt+ deriving (Show, Eq)++newtype KXAlgorithm = KXAlgorithm CInt+ deriving (Show, Eq)++newtype ParamsType = ParamsType CInt+ deriving (Show, Eq)++newtype CredentialsType = CredentialsType CInt+ deriving (Show, Eq)++newtype MACAlgorithm = MACAlgorithm CInt+ deriving (Show, Eq)++newtype DigestAlgorithm = DigestAlgorithm CInt+ deriving (Show, Eq)++newtype CompressionMethod = CompressionMethod CInt+ deriving (Show, Eq)++newtype ConnectionEnd = ConnectionEnd CInt+ deriving (Show, Eq)++newtype AlertLevel = AlertLevel CInt+ deriving (Show, Eq)++newtype AlertDescription = AlertDescription CInt+ deriving (Show, Eq)++newtype HandshakeDescription = HandshakeDescription CInt+ deriving (Show, Eq)++newtype CertificateStatus = CertificateStatus CInt+ deriving (Show, Eq)++newtype CertificateRequest = CertificateRequest CInt+ deriving (Show, Eq)++newtype OpenPGPCrtStatus = OpenPGPCrtStatus CInt+ deriving (Show, Eq)++newtype CloseRequest = CloseRequest CInt+ deriving (Show, Eq)++newtype Protocol = Protocol CInt+ deriving (Show, Eq)++newtype CertificateType = CertificateType CInt+ deriving (Show, Eq)++newtype X509CrtFormat = X509CrtFormat CInt+ deriving (Show, Eq)++newtype CertificatePrintFormats = CertificatePrintFormats CInt+ deriving (Show, Eq)++newtype PKAlgorithm = PKAlgorithm CInt+ deriving (Show, Eq)++newtype SignAlgorithm = SignAlgorithm CInt+ deriving (Show, Eq)++newtype Credentials = Credentials (Ptr Credentials)+newtype Transport = Transport (Ptr Transport)+newtype Session = Session (Ptr Session)+newtype DHParams = DHParams (Ptr DHParams)+newtype RSAParams = RSAParams (Ptr RSAParams)+newtype Priority = Priority (Ptr Priority)++newtype Datum = Datum (Ptr Word8, CUInt)++-- }}}++-- Global library info / state {{{++foreign import ccall safe "gnutls_check_version"+ gnutls_check_version :: CString -> IO CString++foreign import ccall safe "gnutls_extra_check_version"+ gnutls_extra_check_version :: CString -> IO CString++foreign import ccall safe "gnutls_global_init"+ gnutls_global_init :: IO ReturnCode++foreign import ccall safe "gnutls_global_init_extra"+ gnutls_global_init_extra :: IO ReturnCode++foreign import ccall safe "gnutls_global_deinit"+ gnutls_global_deinit :: IO ()++foreign import ccall safe "gnutls_global_set_log_function"+ gnutls_global_set_log_function :: FunPtr (CInt -> CString -> IO ()) -> IO ()++foreign import ccall safe "gnutls_global_set_log_level"+ gnutls_global_set_log_level :: CInt -> IO ()++-- }}}++-- Error handling {{{++foreign import ccall safe "gnutls_error_is_fatal"+ gnutls_error_is_fatal :: ReturnCode -> IO CInt++foreign import ccall safe "gnutls_perror"+ gnutls_perror :: ReturnCode -> IO ()++foreign import ccall safe "gnutls_strerror"+ gnutls_strerror :: ReturnCode -> IO CString++foreign import ccall safe "gnutls_strerror_name"+ gnutls_strerror_name :: ReturnCode -> IO CString++-- }}}++-- Sessions {{{++foreign import ccall safe "gnutls_init"+ gnutls_init :: Ptr (Ptr Session) -> ConnectionEnd -> IO ReturnCode++foreign import ccall safe "gnutls_deinit"+ gnutls_deinit :: Session -> IO ()++foreign import ccall safe "gnutls_handshake"+ gnutls_handshake :: Session -> IO ReturnCode++foreign import ccall safe "gnutls_rehandshake"+ gnutls_rehandshake :: Session -> IO ReturnCode++foreign import ccall safe "gnutls_bye"+ gnutls_bye :: Session -> CloseRequest -> IO ReturnCode++foreign import ccall safe "gnutls_set_default_priority"+ gnutls_set_default_priority :: Session -> IO ReturnCode++-- }}}++-- Alerts {{{++foreign import ccall safe "gnutls_alert_get_name"+ gnutls_alert_get_name :: AlertDescription -> IO CString++foreign import ccall safe "gnutls_error_to_alert"+ gnutls_error_to_alert :: ReturnCode -> Ptr AlertLevel -> IO AlertDescription++foreign import ccall safe "gnutls_alert_get"+ gnutls_alert_get :: Session -> IO AlertDescription++foreign import ccall safe "gnutls_alert_send_appropriate"+ gnutls_alert_send_appropriate :: Session -> ReturnCode -> IO ReturnCode++foreign import ccall safe "gnutls_alert_send"+ gnutls_alert_send :: Session -> AlertLevel -> AlertDescription -> IO ReturnCode++-- }}}++-- Certificates {{{++foreign import ccall safe "gnutls_certificate_allocate_credentials"+ gnutls_certificate_allocate_credentials :: Ptr (Ptr Credentials) -> IO ReturnCode++foreign import ccall safe "&gnutls_certificate_free_credentials"+ gnutls_certificate_free_credentials_funptr :: FunPtr (Ptr Credentials -> IO ())++foreign import ccall safe "gnutls_certificate_type_get_id"+ gnutls_certificate_type_get_id :: CString -> IO CertificateType++foreign import ccall safe "gnutls_certificate_type_get_name"+ gnutls_certificate_type_get_name :: CertificateType -> IO CString++foreign import ccall safe "gnutls_certificate_type_get"+ gnutls_certificate_type_get :: Session -> IO CertificateType++foreign import ccall safe "gnutls_certificate_type_list"+ gnutls_certificate_type_list :: IO (Ptr CertificateType)++foreign import ccall safe "gnutls_certificate_type_set_priority"+ gnutls_certificate_type_set_priority :: Session -> Ptr CInt -> IO ReturnCode++-- }}}++-- Credentials {{{++foreign import ccall safe "gnutls_credentials_clear"+ gnutls_credentials_clear :: Session -> IO ()++foreign import ccall safe "gnutls_credentials_set"+ gnutls_credentials_set :: Session -> CredentialsType -> Ptr a -> IO ReturnCode++-- }}}++-- Records {{{++foreign import ccall safe "gnutls_record_check_pending"+ gnutls_record_check_pending :: Session -> IO CSize++foreign import ccall safe "gnutls_record_disable_padding"+ gnutls_record_disable_padding :: Session -> IO ()++foreign import ccall safe "gnutls_record_get_direction"+ gnutls_record_get_direction :: Session -> IO CInt++foreign import ccall safe "gnutls_record_get_max_size"+ gnutls_record_get_max_size :: Session -> IO CSize++foreign import ccall safe "gnutls_record_recv"+ gnutls_record_recv :: Session -> Ptr a -> CSize -> IO CSize++foreign import ccall safe "gnutls_record_send"+ gnutls_record_send :: Session -> Ptr a -> CSize -> IO CSize++foreign import ccall safe "gnutls_record_set_max_size"+ gnutls_record_set_max_size :: Session -> CSize -> IO CSize++-- }}}++-- Transports {{{++type TransportFunc = Transport -> Ptr () -> CSize -> IO CSize++foreign import ccall safe "gnutls_transport_set_push_function"+ gnutls_transport_set_push_function :: Session -> FunPtr TransportFunc -> IO ()++foreign import ccall safe "gnutls_transport_set_pull_function"+ gnutls_transport_set_pull_function :: Session -> FunPtr TransportFunc -> IO ()++foreign import ccall "wrapper"+ wrapTransportFunc :: TransportFunc -> IO (FunPtr TransportFunc)++-- }}}++-- Utility {{{++foreign import ccall safe "gnutls_global_set_mem_functions"+ gnutls_global_set_mem_functions+ :: FunPtr (CSize -> IO (Ptr ()))+ -> FunPtr (CSize -> CSize -> IO (Ptr ()))+ -> FunPtr (Ptr () -> IO CInt)+ -> FunPtr (Ptr () -> CSize -> IO (Ptr ()))+ -> FunPtr (Ptr () -> IO ())+ -> IO ()++foreign import ccall safe "gnutls_malloc"+ gnutls_malloc :: CSize -> IO (Ptr a)++foreign import ccall safe "gnutls_free"+ gnutls_free :: Ptr a -> IO ()++foreign import ccall safe "gnutls_hex2bin"+ gnutls_hex2bin :: CString -> CSize -> Ptr Word8 -> Ptr CSize -> IO ReturnCode++foreign import ccall safe "gnutls_hex_decode"+ gnutls_hex_decode :: Ptr Datum -> Ptr Word8 -> Ptr CSize -> IO ReturnCode++foreign import ccall safe "gnutls_hex_encode"+ gnutls_hex_encode :: Ptr Datum -> CString -> Ptr CSize -> IO ReturnCode++-- }}}
+ Setup.hs view
@@ -0,0 +1,2 @@+import Distribution.Simple+main = defaultMain
+ gnutls.cabal view
@@ -0,0 +1,37 @@+name: gnutls+version: 0.1+stability: experimental+synopsis: Bindings for GNU TLS+license: GPL-3+license-file: license.txt+author: John Millikin+maintainer: jmillikin@gmail.com+build-type: Simple+cabal-version: >=1.6+category: Network++description:+ You almost certainly don't want to depend on this release.+ .+ This is a pre-alpha, almost useless release; its only purpose is to enable+ TLS support in some of my other libraries. More complete bindings for GNU TLS+ will be released at a later date.++library+ ghc-options: -Wall -fno-warn-unused-do-bind++ build-depends:+ base >=3 && < 5+ , bytestring >= 0.9 && < 0.10+ , transformers >= 0.2 && < 0.3+ , monads-tf >= 0.1 && < 0.2++ extra-libraries: gnutls, gnutls-extra+ pkgconfig-depends: gnutls, gnutls-extra++ exposed-modules:+ Network.Protocol.TLS.GNU++ other-modules:+ Network.Protocol.TLS.GNU.Foreign+ Network.Protocol.TLS.GNU.ErrorT
+ license.txt view
@@ -0,0 +1,674 @@+ GNU GENERAL PUBLIC LICENSE+ Version 3, 29 June 2007++ Copyright (C) 2007 Free Software Foundation, Inc. <http://fsf.org/>+ Everyone is permitted to copy and distribute verbatim copies+ of this license document, but changing it is not allowed.++ Preamble++ The GNU General Public License is a free, copyleft license for+software and other kinds of works.++ The licenses for most software and other practical works are designed+to take away your freedom to share and change the works. By contrast,+the GNU General Public License is intended to guarantee your freedom to+share and change all versions of a program--to make sure it remains free+software for all its users. We, the Free Software Foundation, use the+GNU General Public License for most of our software; it applies also to+any other work released this way by its authors. You can apply it to+your programs, too.++ When we speak of free software, we are referring to freedom, not+price. Our General Public Licenses are designed to make sure that you+have the freedom to distribute copies of free software (and charge for+them if you wish), that you receive source code or can get it if you+want it, that you can change the software or use pieces of it in new+free programs, and that you know you can do these things.++ To protect your rights, we need to prevent others from denying you+these rights or asking you to surrender the rights. Therefore, you have+certain responsibilities if you distribute copies of the software, or if+you modify it: responsibilities to respect the freedom of others.++ For example, if you distribute copies of such a program, whether+gratis or for a fee, you must pass on to the recipients the same+freedoms that you received. You must make sure that they, too, receive+or can get the source code. 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EXCEPT WHEN OTHERWISE STATED IN WRITING THE COPYRIGHT+HOLDERS AND/OR OTHER PARTIES PROVIDE THE PROGRAM "AS IS" WITHOUT WARRANTY+OF ANY KIND, EITHER EXPRESSED OR IMPLIED, INCLUDING, BUT NOT LIMITED TO,+THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR+PURPOSE. THE ENTIRE RISK AS TO THE QUALITY AND PERFORMANCE OF THE PROGRAM+IS WITH YOU. SHOULD THE PROGRAM PROVE DEFECTIVE, YOU ASSUME THE COST OF+ALL NECESSARY SERVICING, REPAIR OR CORRECTION.++ 16. 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Interpretation of Sections 15 and 16.++ If the disclaimer of warranty and limitation of liability provided+above cannot be given local legal effect according to their terms,+reviewing courts shall apply local law that most closely approximates+an absolute waiver of all civil liability in connection with the+Program, unless a warranty or assumption of liability accompanies a+copy of the Program in return for a fee.++ END OF TERMS AND CONDITIONS++ How to Apply These Terms to Your New Programs++ If you develop a new program, and you want it to be of the greatest+possible use to the public, the best way to achieve this is to make it+free software which everyone can redistribute and change under these terms.++ To do so, attach the following notices to the program. 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If not, see <http://www.gnu.org/licenses/>.++Also add information on how to contact you by electronic and paper mail.++ If the program does terminal interaction, make it output a short+notice like this when it starts in an interactive mode:++ <program> Copyright (C) <year> <name of author>+ This program comes with ABSOLUTELY NO WARRANTY; for details type `show w'.+ This is free software, and you are welcome to redistribute it+ under certain conditions; type `show c' for details.++The hypothetical commands `show w' and `show c' should show the appropriate+parts of the General Public License. Of course, your program's commands+might be different; for a GUI interface, you would use an "about box".++ You should also get your employer (if you work as a programmer) or school,+if any, to sign a "copyright disclaimer" for the program, if necessary.+For more information on this, and how to apply and follow the GNU GPL, see+<http://www.gnu.org/licenses/>.++ The GNU General Public License does not permit incorporating your program+into proprietary programs. If your program is a subroutine library, you+may consider it more useful to permit linking proprietary applications with+the library. If this is what you want to do, use the GNU Lesser General+Public License instead of this License. But first, please read+<http://www.gnu.org/philosophy/why-not-lgpl.html>.