Raaz.Core.ByteSource

Module define byte sources.

Byte sources.

Cryptographic input come from various sources; they can come from network sockets or might be just a string in the Haskell. To give a uniform interfaces for all such inputs, we define the abstract concept of a byte source. Essentially a byte source is one from which we can fill a buffer with bytes.

Among instances of ByteSource, some like for example ByteString are pure in the sense filling a buffer with bytes from such a source has no other side-effects. This is in contrast to a source like a sockets. The type class PureByteSource captures such byte sources.

class ByteSource src where

Abstract byte sources. A bytesource is something that you can use to fill a buffer.

WARNING: The source is required to return Exhausted in the boundary case where it has exactly the number of bytes requested. In other words, if the source returns Remaining on any particular request, there should be at least 1 additional byte left on the source for the next request. Cryptographic block primitives have do certain special processing for the last block and it is required to know whether the last block has been read or not.

Minimal complete definition

fillBytes

Methods

fillBytes :: BYTES Int -> src -> Pointer -> IO (FillResult src)

Fills a buffer from the source.

Instances

ByteSource Handle

__WARNING:_ The fillBytes may block.

Methods

fillBytes :: BYTES Int -> Handle -> Pointer -> IO (FillResult Handle)

ByteSource ByteString

Methods

fillBytes :: BYTES Int -> ByteString -> Pointer -> IO (FillResult ByteString)

ByteSource ByteString

Methods

fillBytes :: BYTES Int -> ByteString -> Pointer -> IO (FillResult ByteString)

ByteSource src => ByteSource [src]

Methods

fillBytes :: BYTES Int -> [src] -> Pointer -> IO (FillResult [src])

ByteSource src => ByteSource (Maybe src)

Methods

fillBytes :: BYTES Int -> Maybe src -> Pointer -> IO (FillResult (Maybe src))

class ByteSource src => PureByteSource src

A byte source src is pure if filling from it does not have any other side effect on the state of the byte source. Formally, two different fills form the same source should fill the buffer with the same bytes. This additional constraint on the source helps to purify certain crypto computations like computing the hash or mac of the source. Usualy sources like ByteString etc are pure byte sources. A file handle is a byte source that is not a pure source.

Instances

PureByteSource ByteString

PureByteSource ByteString

PureByteSource src => PureByteSource [src]

PureByteSource src => PureByteSource (Maybe src)

data FillResult a

This type captures the result of a fill operation.

Constructors

Remaining a

There is still bytes left.

Exhausted (BYTES Int)

source exhausted with so much bytes read.

Instances

Functor FillResult

Methods

fmap :: (a -> b) -> FillResult a -> FillResult b

(<$) :: a -> FillResult b -> FillResult a

Eq a => Eq (FillResult a)

Methods

(==) :: FillResult a -> FillResult a -> Bool

(/=) :: FillResult a -> FillResult a -> Bool

Show a => Show (FillResult a)

Methods

showsPrec :: Int -> FillResult a -> ShowS

show :: FillResult a -> String

showList :: [FillResult a] -> ShowS

fill :: (LengthUnit len, ByteSource src) => len -> src -> Pointer -> IO (FillResult src)

A version of fillBytes that takes type safe lengths as input.

processChunks :: (MonadIO m, LengthUnit chunkSize, ByteSource src) => m a -> (BYTES Int -> m b) -> src -> chunkSize -> Pointer -> m b

Process data from a source in chunks of a particular size.

withFillResult

Arguments

:: (a -> b)

stuff to do when filled

-> (BYTES Int -> b)

stuff to do when exhausted

-> FillResult a

the fill result to process

-> b

Combinator to handle a fill result.