A module containing SHA-256 bindings

This API is based on 4 different functions, similar to the lowlevel operations of a typical hash:

• init: create a new hash context
• update: update non-destructively a new hash context with a strict bytestring
• updates: same as update, except that it takes a list of strict bytestrings
• finalize: finalize the context and returns a digest bytestring.

all those operations are completely pure, and instead of changing the context as usual in others language, it re-allocates a new context each time.

Example:

import qualified Data.ByteString
import qualified Crypto.Hash.SHA256 as SHA256

main = print digest
  where
    digest = SHA256.finalize ctx
    ctx    = foldl SHA256.update ctx0 (map Data.ByteString.pack [ [1,2,3], [4,5,6] ])
    ctx0   = SHA256.init

This API use the incremental API under the hood to provide the common all-in-one operations to create digests out of a ByteString and lazy ByteString.

• hash: create a digest (init + update + finalize) from a strict ByteString
• hashlazy: create a digest (init + update + finalize) from a lazy ByteString
• hashlazyAndLength: create a digest (init + update + finalizeAndLength) from a lazy ByteString

Example:

import qualified Data.ByteString
import qualified Crypto.Hash.SHA256 as SHA256

main = print $ SHA256.hash (Data.ByteString.pack [0..255])

NOTE: The returned digest is a binary ByteString. For converting to a base16/hex encoded digest the base16-bytestring package is recommended.

RFC2104-compatible HMAC-SHA-256 digests

RFC5869-compatible HKDF-SHA-256 key derivation function