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Diffstat (limited to 'src/Data/Digest/Internal.chs')
| -rw-r--r-- | src/Data/Digest/Internal.chs | 122 |
1 files changed, 0 insertions, 122 deletions
diff --git a/src/Data/Digest/Internal.chs b/src/Data/Digest/Internal.chs deleted file mode 100644 index 6478810..0000000 --- a/src/Data/Digest/Internal.chs +++ /dev/null @@ -1,122 +0,0 @@ --- Copyright 2017 Google LLC --- --- Licensed under the Apache License, Version 2.0 (the "License"); you may not --- use this file except in compliance with the License. You may obtain a copy of --- the License at --- --- https://www.apache.org/licenses/LICENSE-2.0 --- --- Unless required by applicable law or agreed to in writing, software --- distributed under the License is distributed on an "AS IS" BASIS, WITHOUT --- WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the --- License for the specific language governing permissions and limitations under --- the License. - -module Data.Digest.Internal where - -import Data.Bits (Bits((.&.)), shiftR) -import Data.ByteString (ByteString) -import qualified Data.ByteString as ByteString -import qualified Data.ByteString.Lazy as ByteString.Lazy -import qualified Data.ByteString.Unsafe as ByteString -import Data.Char (intToDigit) -import Data.Word (Word8) -import Foreign - (FinalizerPtr, ForeignPtr, Ptr, Storable(peek), addForeignPtrFinalizer, - alloca, allocaArray, mallocForeignPtr, withForeignPtr) -import Foreign.C.Types -import Foreign.Marshal.Unsafe (unsafeLocalState) -import Unsafe.Coerce (unsafeCoerce) - -{#import Internal.Base#} -{#import Internal.Digest#} () -import Foreign.Ptr.Cast (asVoidPtr) -import Result - -type LazyByteString = ByteString.Lazy.ByteString - -#include <openssl/digest.h> - --- First, we build basic bindings to the BoringSSL EVP interface. - --- Imported functions from BoringSSL. See --- https://commondatastorage.googleapis.com/chromium-boringssl-docs/digest.h.html --- for documentation. - -evpMaxMdSize :: Int -evpMaxMdSize = {#const EVP_MAX_MD_SIZE#} - --- Some of these functions return 'CInt' even though they can never fail. Wrap --- them to prevent warnings. - -evpDigestUpdate :: Ptr EvpMdCtx -> Ptr a -> CULong -> IO () -evpDigestUpdate ctx md bytes = - alwaysSucceeds $ {#call EVP_DigestUpdate as ^#} ctx (asVoidPtr md) bytes - -evpDigestFinalEx :: Ptr EvpMdCtx -> Ptr CUChar -> Ptr CUInt -> IO () -evpDigestFinalEx ctx mdOut outSize = - alwaysSucceeds $ {#call EVP_DigestFinal_ex as ^#} ctx mdOut outSize - --- Convert functions that can in fact fail to throw exceptions instead. - -evpDigestInitEx :: Ptr EvpMdCtx -> Ptr EvpMd -> Ptr Engine -> IO () -evpDigestInitEx ctx md engine = - requireSuccess $ {#call EVP_DigestInit_ex as ^#} ctx md engine - --- Now we can build a memory-safe allocator. - --- | Memory-safe allocator for 'EvpMdCtx'. -mallocEvpMdCtx :: IO (ForeignPtr EvpMdCtx) -mallocEvpMdCtx = do - fp <- mallocForeignPtr - withForeignPtr fp {#call EVP_MD_CTX_init as ^#} - addForeignPtrFinalizer btlsFinalizeEvpMdCtxPtr fp - return fp - -foreign import ccall "&btlsFinalizeEvpMdCtx" - btlsFinalizeEvpMdCtxPtr :: FinalizerPtr EvpMdCtx - --- Finally, we're ready to actually implement the hashing interface. - --- | A cryptographic hash function. -newtype Algorithm = Algorithm (Ptr EvpMd) - --- | The result of a hash operation. -newtype Digest = - Digest ByteString - deriving (Eq, Ord) - -instance Show Digest where - show (Digest d) = ByteString.foldr showHexPadded [] d - where - showHexPadded b xs = - hexit (b `shiftR` 4 .&. 0x0f) : hexit (b .&. 0x0f) : xs - hexit = intToDigit . fromIntegral :: Word8 -> Char - --- | Hashes according to the given 'Algorithm'. -hash :: Algorithm -> LazyByteString -> Digest -hash (Algorithm md) bytes = - unsafeLocalState $ do - ctxFP <- mallocEvpMdCtx - withForeignPtr ctxFP $ \ctx -> do - evpDigestInitEx ctx md noEngine - mapM_ (updateBytes ctx) (ByteString.Lazy.toChunks bytes) - d <- - allocaArray evpMaxMdSize $ \mdOut -> - alloca $ \pOutSize -> do - evpDigestFinalEx ctx mdOut pOutSize - outSize <- fromIntegral <$> peek pOutSize - -- 'mdOut' is a 'Ptr CUChar'. However, to make life more - -- interesting, 'CString' is a 'Ptr CChar', and 'CChar' is signed. - -- This is especially unfortunate given that all we really want to - -- do is convert to a 'ByteString', which is unsigned. To work - -- around it, we're going to cheat and let Haskell reinterpret-cast - -- 'mdOut' to 'Ptr CChar' before it does its 'ByteString' ingestion. - ByteString.packCStringLen (unsafeCoerce mdOut, outSize) - return (Digest d) - where - updateBytes ctx chunk = - -- 'mdUpdate' treats its @buf@ argument as @const@, so the sharing - -- inherent in 'ByteString.unsafeUseAsCStringLen' is fine. - ByteString.unsafeUseAsCStringLen chunk $ \(buf, len) -> - evpDigestUpdate ctx buf (fromIntegral len) |