{-# OPTIONS_GHC -fno-warn-name-shadowing #-} {-# LANGUAGE DeriveFunctor #-} {-# LANGUAGE DeriveFoldable #-} {-# LANGUAGE DeriveTraversable #-} {-# LANGUAGE NamedFieldPuns #-} -- | Functions for handling SSL connections. These functions use GHC specific -- calls to cooperative the with the scheduler so that 'blocking' functions -- only actually block the Haskell thread, not a whole OS thread. module OpenSSL.Session ( -- * Contexts SSLContext , context , contextSetPrivateKey , contextSetCertificate , contextSetPrivateKeyFile , contextSetCertificateFile , contextSetCiphers , contextSetDefaultCiphers , contextCheckPrivateKey , VerificationMode(..) , contextSetVerificationMode , contextSetCAFile , contextSetCADirectory , contextGetCAStore -- * SSL connections , SSL , SSLResult(..) , connection , fdConnection , accept , tryAccept , connect , tryConnect , read , tryRead , write , tryWrite , lazyRead , lazyWrite , shutdown , tryShutdown , ShutdownType(..) , getPeerCertificate , getVerifyResult , sslSocket , sslFd -- * SSL Exceptions , SomeSSLException , ConnectionAbruptlyTerminated , ProtocolError(..) ) where #include "openssl/ssl.h" import Prelude hiding (catch, read, ioError, mapM, mapM_) import Control.Concurrent (threadWaitWrite, threadWaitRead, runInBoundThread) import Control.Concurrent.QSem import Control.Exception import Control.Applicative ((<$>), (<$)) import Control.Monad (unless) import Data.Typeable import Data.Foldable (Foldable, mapM_, forM_) import Data.Traversable (Traversable, mapM) import Data.Maybe (fromMaybe) import Data.IORef import Foreign import Foreign.C import qualified Foreign.Concurrent as FC import qualified Data.ByteString as B import qualified Data.ByteString.Internal as B import qualified Data.ByteString.Unsafe as B import qualified Data.ByteString.Lazy as L import qualified Data.ByteString.Lazy.Internal as L import System.IO.Unsafe import System.Posix.Types (Fd(..)) import Network.Socket (Socket(..)) import OpenSSL.ERR import OpenSSL.EVP.PKey import OpenSSL.EVP.Internal import OpenSSL.Utils import OpenSSL.X509 (X509, X509_, wrapX509, withX509Ptr) import OpenSSL.X509.Store type VerifyCb = Bool -> Ptr X509_STORE_CTX -> IO Bool foreign import ccall "wrapper" mkVerifyCb :: VerifyCb -> IO (FunPtr VerifyCb) data SSLContext_ -- | An SSL context. Contexts carry configuration such as a server's private -- key, root CA certiifcates etc. Contexts are stateful IO objects; they -- start empty and various options are set on them by the functions in this -- module. Note that an empty context will pretty much cause any operation to -- fail since it doesn't even have any ciphers enabled. -- -- Contexts are not thread safe so they carry a QSem with them which only -- lets a single thread work inside them at a time. Thus, one must always use -- withContext, not withForeignPtr directly. data SSLContext = SSLContext { ctxSem :: QSem , ctxPtr :: ForeignPtr SSLContext_ , ctxVfCb :: IORef (Maybe (FunPtr VerifyCb)) } deriving Typeable data SSLMethod_ foreign import ccall unsafe "SSL_CTX_new" _ssl_ctx_new :: Ptr SSLMethod_ -> IO (Ptr SSLContext_) foreign import ccall unsafe "SSL_CTX_free" _ssl_ctx_free :: Ptr SSLContext_ -> IO () foreign import ccall unsafe "SSLv23_method" _ssl_method :: IO (Ptr SSLMethod_) -- | Create a new SSL context. context :: IO SSLContext context = do ctx <- _ssl_method >>= _ssl_ctx_new cbRef <- newIORef Nothing ptr <- FC.newForeignPtr ctx $ do _ssl_ctx_free ctx readIORef cbRef >>= mapM_ freeHaskellFunPtr sem <- newQSem 1 return $ SSLContext { ctxSem = sem, ctxPtr = ptr, ctxVfCb = cbRef } -- | Run the given action with the raw context pointer and obtain the lock -- while doing so. withContext :: SSLContext -> (Ptr SSLContext_ -> IO a) -> IO a withContext (SSLContext {ctxSem, ctxPtr}) action = do waitQSem ctxSem finally (withForeignPtr ctxPtr action) $ signalQSem ctxSem touchContext :: SSLContext -> IO () touchContext = touchForeignPtr . ctxPtr contextLoadFile :: (Ptr SSLContext_ -> CString -> CInt -> IO CInt) -> SSLContext -> String -> IO () contextLoadFile f context path = withContext context $ \ctx -> withCString path $ \cpath -> do result <- f ctx cpath (#const SSL_FILETYPE_PEM) unless (result == 1) $ f ctx cpath (#const SSL_FILETYPE_ASN1) >>= failIf_ (/= 1) foreign import ccall unsafe "SSL_CTX_use_PrivateKey" _ssl_ctx_use_privatekey :: Ptr SSLContext_ -> Ptr EVP_PKEY -> IO CInt foreign import ccall unsafe "SSL_CTX_use_certificate" _ssl_ctx_use_certificate :: Ptr SSLContext_ -> Ptr X509_ -> IO CInt -- | Install a private key into a context. contextSetPrivateKey :: KeyPair k => SSLContext -> k -> IO () contextSetPrivateKey context key = withContext context $ \ ctx -> withPKeyPtr' key $ \ keyPtr -> _ssl_ctx_use_privatekey ctx keyPtr >>= failIf_ (/= 1) -- | Install a certificate (public key) into a context. contextSetCertificate :: SSLContext -> X509 -> IO () contextSetCertificate context cert = withContext context $ \ ctx -> withX509Ptr cert $ \ certPtr -> _ssl_ctx_use_certificate ctx certPtr >>= failIf_ (/= 1) foreign import ccall unsafe "SSL_CTX_use_PrivateKey_file" _ssl_ctx_use_privatekey_file :: Ptr SSLContext_ -> CString -> CInt -> IO CInt foreign import ccall unsafe "SSL_CTX_use_certificate_file" _ssl_ctx_use_certificate_file :: Ptr SSLContext_ -> CString -> CInt -> IO CInt -- | Install a private key file in a context. The key is given as a path to the -- file which contains the key. The file is parsed first as PEM and, if that -- fails, as ASN1. If both fail, an exception is raised. contextSetPrivateKeyFile :: SSLContext -> FilePath -> IO () contextSetPrivateKeyFile = contextLoadFile _ssl_ctx_use_privatekey_file -- | Install a certificate (public key) file in a context. The key is given as -- a path to the file which contains the key. The file is parsed first as PEM -- and, if that fails, as ASN1. If both fail, an exception is raised. contextSetCertificateFile :: SSLContext -> FilePath -> IO () contextSetCertificateFile = contextLoadFile _ssl_ctx_use_certificate_file foreign import ccall unsafe "SSL_CTX_set_cipher_list" _ssl_ctx_set_cipher_list :: Ptr SSLContext_ -> CString -> IO CInt -- | Set the ciphers to be used by the given context. The string argument is a -- list of ciphers, comma separated, as given at -- http://www.openssl.org/docs/apps/ciphers.html -- -- Unrecognised ciphers are ignored. If no ciphers from the list are -- recognised, an exception is raised. contextSetCiphers :: SSLContext -> String -> IO () contextSetCiphers context list = withContext context $ \ctx -> withCString list $ \cpath -> _ssl_ctx_set_cipher_list ctx cpath >>= failIf_ (/= 1) contextSetDefaultCiphers :: SSLContext -> IO () contextSetDefaultCiphers = flip contextSetCiphers "DEFAULT" foreign import ccall unsafe "SSL_CTX_check_private_key" _ssl_ctx_check_private_key :: Ptr SSLContext_ -> IO CInt -- | Return true iff the private key installed in the given context matches the -- certificate also installed. contextCheckPrivateKey :: SSLContext -> IO Bool contextCheckPrivateKey context = withContext context $ \ctx -> fmap (== 1) (_ssl_ctx_check_private_key ctx) -- | See data VerificationMode = VerifyNone | VerifyPeer { vpFailIfNoPeerCert :: Bool -- ^ is a certificate required , vpClientOnce :: Bool -- ^ only request once per connection , vpCallback :: Maybe (Bool -> X509StoreCtx -> IO Bool) -- ^ optional callback } deriving Typeable foreign import ccall unsafe "SSL_CTX_set_verify" _ssl_set_verify_mode :: Ptr SSLContext_ -> CInt -> FunPtr VerifyCb -> IO () contextSetVerificationMode :: SSLContext -> VerificationMode -> IO () contextSetVerificationMode context VerifyNone = withContext context $ \ctx -> _ssl_set_verify_mode ctx (#const SSL_VERIFY_NONE) nullFunPtr >> return () contextSetVerificationMode context (VerifyPeer reqp oncep cbp) = do let mode = (#const SSL_VERIFY_PEER) .|. (if reqp then (#const SSL_VERIFY_FAIL_IF_NO_PEER_CERT) else 0) .|. (if oncep then (#const SSL_VERIFY_CLIENT_ONCE) else 0) withContext context $ \ctx -> do let cbRef = ctxVfCb context newCb <- mapM mkVerifyCb $ (<$> cbp) $ \cb pvf pStoreCtx -> cb pvf =<< wrapX509StoreCtx (return ()) pStoreCtx oldCb <- readIORef cbRef writeIORef cbRef newCb forM_ oldCb freeHaskellFunPtr _ssl_set_verify_mode ctx mode $ fromMaybe nullFunPtr newCb return () foreign import ccall unsafe "SSL_CTX_load_verify_locations" _ssl_load_verify_locations :: Ptr SSLContext_ -> Ptr CChar -> Ptr CChar -> IO CInt -- | Set the location of a PEM encoded list of CA certificates to be used when -- verifying a server's certificate contextSetCAFile :: SSLContext -> FilePath -> IO () contextSetCAFile context path = withContext context $ \ctx -> withCString path $ \cpath -> _ssl_load_verify_locations ctx cpath nullPtr >>= failIf_ (/= 1) -- | Set the path to a directory which contains the PEM encoded CA root -- certificates. This is an alternative to 'contextSetCAFile'. See -- for -- details of the file naming scheme contextSetCADirectory :: SSLContext -> FilePath -> IO () contextSetCADirectory context path = withContext context $ \ctx -> withCString path $ \cpath -> _ssl_load_verify_locations ctx nullPtr cpath >>= failIf_ (/= 1) foreign import ccall unsafe "SSL_CTX_get_cert_store" _ssl_get_cert_store :: Ptr SSLContext_ -> IO (Ptr X509_STORE) -- | Get a reference to, not a copy of, the X.509 certificate storage -- in the SSL context. contextGetCAStore :: SSLContext -> IO X509Store contextGetCAStore context = withContext context $ \ ctx -> _ssl_get_cert_store ctx >>= wrapX509Store (touchContext context) data SSL_ -- | This is the type of an SSL connection -- -- SSL objects are not thread safe, so they carry a QSem around with them -- which only lets a single thread work inside them at a time. Thus, one must -- always use withSSL, rather than withForeignPtr directly. -- -- IO with SSL objects is non-blocking and many SSL functions return a error -- code which signifies that it needs to read or write more data. We handle -- these calls and call threadWaitRead and threadWaitWrite at the correct -- times. Thus multiple OS threads can be 'blocked' inside IO in the same SSL -- object at a time, because they aren't really in the SSL object, they are -- waiting for the RTS to wake the Haskell thread. data SSL = SSL { sslSem :: QSem , sslPtr :: ForeignPtr SSL_ , sslFd :: Fd -- ^ Get the underlying socket Fd , sslSocket :: Maybe Socket -- ^ Get the socket underlying an SSL connection } deriving Typeable foreign import ccall unsafe "SSL_new" _ssl_new :: Ptr SSLContext_ -> IO (Ptr SSL_) foreign import ccall unsafe "&SSL_free" _ssl_free :: FunPtr (Ptr SSL_ -> IO ()) foreign import ccall unsafe "SSL_set_fd" _ssl_set_fd :: Ptr SSL_ -> CInt -> IO () connection' :: SSLContext -> Fd -> Maybe Socket -> IO SSL connection' context fd@(Fd fdInt) sock = do sem <- newQSem 1 ssl <- withContext context $ \ctx -> do ssl <- _ssl_new ctx >>= failIfNull _ssl_set_fd ssl fdInt return ssl fpssl <- newForeignPtr _ssl_free ssl return $ SSL { sslSem = sem , sslPtr = fpssl , sslFd = fd , sslSocket = sock } -- | Wrap a Socket in an SSL connection. Reading and writing to the Socket -- after this will cause weird errors in the SSL code. The SSL object -- carries a handle to the Socket so you need not worry about the garbage -- collector closing the file descriptor out from under you. connection :: SSLContext -> Socket -> IO SSL connection context sock@(MkSocket fd _ _ _ _) = connection' context (Fd fd) (Just sock) -- | Wrap a socket Fd in an SSL connection. fdConnection :: SSLContext -> Fd -> IO SSL fdConnection context fd = connection' context fd Nothing withSSL :: SSL -> (Ptr SSL_ -> IO a) -> IO a withSSL (SSL {sslSem, sslPtr}) action = do waitQSem sslSem finally (withForeignPtr sslPtr action) $ signalQSem sslSem foreign import ccall "SSL_accept" _ssl_accept :: Ptr SSL_ -> IO CInt foreign import ccall "SSL_connect" _ssl_connect :: Ptr SSL_ -> IO CInt foreign import ccall unsafe "SSL_get_error" _ssl_get_error :: Ptr SSL_ -> CInt -> IO CInt throwSSLException :: String -> CInt -> IO a throwSSLException loc ret = do e <- getError if e == 0 then case ret of 0 -> throwIO ConnectionAbruptlyTerminated _ -> throwErrno loc else errorString e >>= throwIO . ProtocolError -- | This is the type of an SSL IO operation. Errors are handled by -- exceptions while everything else is one of these. Note that reading -- from an SSL socket can result in WantWrite and vice versa. data SSLResult a = SSLDone a -- ^ operation finished successfully | WantRead -- ^ needs more data from the network | WantWrite -- ^ needs more outgoing buffer space deriving (Eq, Show, Functor, Foldable, Traversable, Typeable) -- | Block until the operation is finished. sslBlock :: (SSL -> IO (SSLResult a)) -> SSL -> IO a sslBlock action ssl = do result <- action ssl case result of SSLDone r -> return r WantRead -> threadWaitRead (sslFd ssl) >> sslBlock action ssl WantWrite -> threadWaitWrite (sslFd ssl) >> sslBlock action ssl -- | Perform an SSL operation which can return non-blocking error codes, thus -- requesting that the operation be performed when data or buffer space is -- availible. sslTryHandshake :: String -> (Ptr SSL_ -> IO CInt) -> SSL -> IO (SSLResult CInt) sslTryHandshake loc action ssl = runInBoundThread $ withSSL ssl $ \sslPtr -> do n <- action sslPtr if n == 1 then return $ SSLDone n else do err <- _ssl_get_error sslPtr n case err of (#const SSL_ERROR_WANT_READ ) -> return WantRead (#const SSL_ERROR_WANT_WRITE) -> return WantWrite _ -> throwSSLException loc n -- | Perform an SSL server handshake accept :: SSL -> IO () accept = sslBlock tryAccept -- | Try to perform an SSL server handshake without blocking tryAccept :: SSL -> IO (SSLResult ()) tryAccept ssl = (() <$) <$> sslTryHandshake "SSL_accept" _ssl_accept ssl -- | Perform an SSL client handshake connect :: SSL -> IO () connect = sslBlock tryConnect -- | Try to perform an SSL client handshake without blocking tryConnect :: SSL -> IO (SSLResult ()) tryConnect ssl = (() <$) <$> sslTryHandshake "SSL_connect" _ssl_connect ssl foreign import ccall "SSL_read" _ssl_read :: Ptr SSL_ -> Ptr Word8 -> CInt -> IO CInt foreign import ccall unsafe "SSL_get_shutdown" _ssl_get_shutdown :: Ptr SSL_ -> IO CInt -- | Perform an SSL operation which operates of a buffer and can return -- non-blocking error codes, thus requesting that it be performed again when -- more data or buffer space is available. -- -- Note that these SSL functions generally require that the arguments to the -- repeated call be exactly the same. This presents an issue because multiple -- threads could try writing at the same time (with different buffers) so the -- calling function should probably hold the lock on the SSL object over the -- whole time (include repeated calls) sslIOInner :: String -- ^ the name of SSL IO function to call -> (Ptr SSL_ -> Ptr Word8 -> CInt -> IO CInt) -- ^ the SSL IO function to call -> Ptr CChar -- ^ the buffer to pass -> Int -- ^ the length to pass -> SSL -> IO (SSLResult CInt) sslIOInner loc f ptr nbytes ssl = runInBoundThread $ withSSL ssl $ \sslPtr -> do n <- f sslPtr (castPtr ptr) $ fromIntegral nbytes if n > 0 then return $ SSLDone $ fromIntegral n else do err <- _ssl_get_error sslPtr n case err of (#const SSL_ERROR_ZERO_RETURN) -> return $ SSLDone $ 0 (#const SSL_ERROR_WANT_READ ) -> return WantRead (#const SSL_ERROR_WANT_WRITE ) -> return WantWrite _ -> throwSSLException loc n -- | Try to read the given number of bytes from an SSL connection. On EOF an -- empty ByteString is returned. If the connection dies without a graceful -- SSL shutdown, an exception is raised. read :: SSL -> Int -> IO B.ByteString read ssl nBytes = sslBlock (`tryRead` nBytes) ssl -- | Try to read the given number of bytes from an SSL connection -- without blocking. tryRead :: SSL -> Int -> IO (SSLResult B.ByteString) tryRead ssl nBytes = do (bs, result) <- B.createAndTrim' nBytes $ \bufPtr -> do result <- sslIOInner "SSL_read" _ssl_read (castPtr bufPtr) nBytes ssl case result of SSLDone n -> return (0, fromIntegral n, SSLDone ()) WantRead -> return (0, 0, WantRead ) WantWrite -> return (0, 0, WantWrite ) return $ bs <$ result foreign import ccall "SSL_write" _ssl_write :: Ptr SSL_ -> Ptr Word8 -> CInt -> IO CInt -- | Write a given ByteString to the SSL connection. Either all the data is -- written or an exception is raised because of an error. write :: SSL -> B.ByteString -> IO () write ssl bs = sslBlock (`tryWrite` bs) ssl >> return () -- | Try to write a given ByteString to the SSL connection without blocking. tryWrite :: SSL -> B.ByteString -> IO (SSLResult ()) tryWrite ssl bs | B.null bs = return $ SSLDone () | otherwise = B.unsafeUseAsCStringLen bs $ \(ptr, len) -> do result <- sslIOInner "SSL_write" _ssl_write ptr len ssl case result of SSLDone 0 -> ioError $ errnoToIOError "SSL_write" ePIPE Nothing Nothing SSLDone _ -> return $ SSLDone () WantRead -> return WantRead WantWrite -> return WantWrite -- | Lazily read all data until reaching EOF. If the connection dies -- without a graceful SSL shutdown, an exception is raised. lazyRead :: SSL -> IO L.ByteString lazyRead ssl = fmap L.fromChunks lazyRead' where chunkSize = L.defaultChunkSize lazyRead' = unsafeInterleaveIO loop loop = do bs <- read ssl chunkSize if B.null bs then -- got EOF return [] else do bss <- lazyRead' return (bs:bss) -- | Write a lazy ByteString to the SSL connection. In contrast to -- 'write', there is a chance that the string is written partway and -- then an exception is raised for an error. The string doesn't -- necessarily have to be finite. lazyWrite :: SSL -> L.ByteString -> IO () lazyWrite ssl lbs = mapM_ (write ssl) $ L.toChunks lbs foreign import ccall "SSL_shutdown" _ssl_shutdown :: Ptr SSL_ -> IO CInt data ShutdownType = Bidirectional -- ^ wait for the peer to also shutdown | Unidirectional -- ^ only send our shutdown deriving (Eq, Show, Typeable) -- | Cleanly shutdown an SSL connection. Note that SSL has a concept of a -- secure shutdown, which is distinct from just closing the TCP connection. -- This performs the former and should always be preferred. -- -- This can either just send a shutdown, or can send and wait for the peer's -- shutdown message. shutdown :: SSL -> ShutdownType -> IO () shutdown ssl ty = sslBlock (`tryShutdown` ty) ssl -- | Try to cleanly shutdown an SSL connection without blocking. tryShutdown :: SSL -> ShutdownType -> IO (SSLResult ()) tryShutdown ssl ty = runInBoundThread $ withSSL ssl $ \sslPtr -> do n <- _ssl_shutdown sslPtr case n of 1 -> return $ SSLDone () 0 -> if ty == Bidirectional then tryShutdown ssl ty else return $ SSLDone () _ -> do err <- _ssl_get_error sslPtr n case err of (#const SSL_ERROR_WANT_READ ) -> return WantRead (#const SSL_ERROR_WANT_WRITE) -> return WantWrite -- SSL_ERROR_SYSCALL/-1 happens when we are -- trying to send the remote peer a "close -- notify" alert but the underlying socket was -- closed at the time. We don't treat this an -- error /if and only if/ we have already -- received a "close notify" from the peer. (#const SSL_ERROR_SYSCALL) -> do sd <- _ssl_get_shutdown sslPtr if sd .&. (#const SSL_RECEIVED_SHUTDOWN) == 0 then throwSSLException "SSL_shutdown" n else return $ SSLDone () _ -> throwSSLException "SSL_shutdown" n foreign import ccall "SSL_get_peer_certificate" _ssl_get_peer_cert :: Ptr SSL_ -> IO (Ptr X509_) -- | After a successful connection, get the certificate of the other party. If -- this is a server connection, you probably won't get a certificate unless -- you asked for it with contextSetVerificationMode getPeerCertificate :: SSL -> IO (Maybe X509) getPeerCertificate ssl = withSSL ssl $ \ssl -> do cert <- _ssl_get_peer_cert ssl if cert == nullPtr then return Nothing else fmap Just (wrapX509 cert) foreign import ccall "SSL_get_verify_result" _ssl_get_verify_result :: Ptr SSL_ -> IO CLong -- | Get the result of verifing the peer's certificate. This is mostly for -- clients to verify the certificate of the server that they have connected -- it. You must set a list of root CA certificates with contextSetCA... for -- this to make sense. -- -- Note that this returns True iff the peer's certificate has a valid chain -- to a root CA. You also need to check that the certificate is correct (i.e. -- has the correct hostname in it) with getPeerCertificate. getVerifyResult :: SSL -> IO Bool getVerifyResult ssl = withSSL ssl $ \ssl -> do r <- _ssl_get_verify_result ssl return $ r == (#const X509_V_OK) -- | The root exception type for all SSL exceptions. data SomeSSLException = forall e. Exception e => SomeSSLException e deriving Typeable instance Show SomeSSLException where show (SomeSSLException e) = show e instance Exception SomeSSLException sslExceptionToException :: Exception e => e -> SomeException sslExceptionToException = toException . SomeSSLException sslExceptionFromException :: Exception e => SomeException -> Maybe e sslExceptionFromException x = do SomeSSLException a <- fromException x cast a -- | The peer uncleanly terminated the connection without sending the -- \"close notify\" alert. data ConnectionAbruptlyTerminated = ConnectionAbruptlyTerminated deriving (Typeable, Show, Eq) instance Exception ConnectionAbruptlyTerminated where toException = sslExceptionToException fromException = sslExceptionFromException -- | A failure in the SSL library occurred, usually a protocol -- error. data ProtocolError = ProtocolError !String deriving (Typeable, Show, Eq) instance Exception ProtocolError where toException = sslExceptionToException fromException = sslExceptionFromException