diff --git a/Crypto/Pbkdf2.hs b/Crypto/Pbkdf2.hs --- a/Crypto/Pbkdf2.hs +++ b/Crypto/Pbkdf2.hs @@ -1,5 +1,5 @@ {-# LANGUAGE Safe #-} -module Crypto.Pbkdf2 (pbkdf2, pbkdf2_iterative) where +module Crypto.Pbkdf2 (pbkdf2, pbkdf2_blocks, pbkdf2_iterative, pbkdf2_iterative_blocks) where import Data.Bits (shiftR) import Data.Bits(xor) @@ -20,7 +20,7 @@ | B.length x == B.length y = B.pack $ B.zipWith xor x y | otherwise = error "xor bytestrings are not of equal length" -pbkdf2_internal createBlocks prf password salt iterations = LB.concat $ map LB.fromStrict $ createBlocks $ first_iteration . hash' +pbkdf2_internal createBlocks prf password salt iterations = createBlocks $ first_iteration . hash' where hash' = prf password first_iteration hash = additional_iterations hash hash 1 @@ -46,6 +46,27 @@ -- calculated as (PRF output input), where output is the output of the previous -- block and input is the added salt for the previous block. Notice that the -- output from the previous block is put in the password filed of the PRF. +pbkdf2_iterative_blocks :: (B.ByteString -> B.ByteString -> B.ByteString) + -- ^ @PRF@, the PRF function to be used for the + -- iterative PBKDF2. The first argument is secret, the + -- second argument is not. + -> B.ByteString -- ^ @Password@, the secret to use in the PBKDF2 computations. + -> B.ByteString -- ^ @Salt@, the not neccesarily secret data to use in the PBKDF2 computations. + -> Integer -- ^ @c@, number of iterations for the the PBKDF2 computations. + -> [B.ByteString] -- ^ @DK@, the output data in the + -- format of an unlimited lazy list of strict + -- ByteStrings, each of which is a block from + -- @PRF@. This can be useful for precalculations of + -- the next block, but by the design of this + -- algorithm it cannot be used to compute blocks in + -- parallel. +pbkdf2_iterative_blocks prf password salt iterations = pbkdf2_internal (createBlocks (B.pack []) 1) prf password salt iterations + where + createBlocks :: B.ByteString -> Bin.Word32 -> (B.ByteString -> B.ByteString) -> [B.ByteString] + createBlocks blockSalt i hash = let prev = (hash $ B.concat [blockSalt, salt, B.pack $ octetsBE i]) + in prev:(createBlocks (prf prev blockSalt) (i + 1) hash) + +-- | This is the same as 'pbkdf2_iterative_blocks', except that it returns a lazy bytestring instead. pbkdf2_iterative :: (B.ByteString -> B.ByteString -> B.ByteString) -- ^ @PRF@, the PRF function to be used for the -- iterative PBKDF2. The first argument is secret, the @@ -54,21 +75,31 @@ -> B.ByteString -- ^ @Salt@, the not neccesarily secret data to use in the PBKDF2 computations. -> Integer -- ^ @c@, number of iterations for the the PBKDF2 computations. -> LB.ByteString -- ^ @DK@, the output data in the format of an unlimited lazy ByteString. -pbkdf2_iterative prf password salt iterations = pbkdf2_internal (createBlocks (B.pack []) 1) prf password salt iterations - where - createBlocks :: B.ByteString -> Bin.Word32 -> (B.ByteString -> B.ByteString) -> [B.ByteString] - createBlocks blockSalt i hash = let prev = (hash $ B.concat [blockSalt, salt, B.pack $ octetsBE i]) - in prev:(createBlocks (prf prev blockSalt) (i + 1) hash) +pbkdf2_iterative prf password salt iterations = LB.concat $ map LB.fromStrict $ pbkdf2_iterative_blocks prf password salt iterations -pbkdf2 :: (B.ByteString -> B.ByteString -> B.ByteString) +-- | This is the standard PBKDF2 algorithm. +pbkdf2_blocks :: (B.ByteString -> B.ByteString -> B.ByteString) -- ^ @PRF@, the PRF function to be used for PBKDF2. The first -- argument is secret, the second argument is not. -> B.ByteString -- ^ @Password@, the secret to use in the PBKDF2 computations. -> B.ByteString -- ^ @Salt@, the not neccesarily secret data to use in the PBKDF2 computations. -> Integer -- ^ @c@, number of iterations for the the PBKDF2 computations. - -> LB.ByteString -- ^ @DK@, the output data in the format of an unlimited lazy ByteString. -pbkdf2 prf password salt iterations = pbkdf2_internal (createBlocks True 1) prf password salt iterations + -> [B.ByteString] -- ^ @DK@, the output data in the + -- format of an unlimited lazy list of strict + -- ByteStrings, each of which is a block from + -- @PRF@. These can be calculated in parallel. +pbkdf2_blocks prf password salt iterations = pbkdf2_internal (createBlocks True 1) prf password salt iterations where createBlocks :: Bool -> Bin.Word32 -> (B.ByteString -> B.ByteString) -> [B.ByteString] createBlocks False 1 _ = error "Hashing algorithm looped, stopping to maintain security of data" -- Paranoia, but that's useful when doing crypto createBlocks _ i hash = (hash $ B.concat [salt, B.pack $ octetsBE i]):(createBlocks False (i + 1) hash) + +-- | This is the same as 'pbkdf2_blocks', except that it returns a lazy bytestring instead. +pbkdf2 :: (B.ByteString -> B.ByteString -> B.ByteString) + -- ^ @PRF@, the PRF function to be used for PBKDF2. The first + -- argument is secret, the second argument is not. + -> B.ByteString -- ^ @Password@, the secret to use in the PBKDF2 computations. + -> B.ByteString -- ^ @Salt@, the not neccesarily secret data to use in the PBKDF2 computations. + -> Integer -- ^ @c@, number of iterations for the the PBKDF2 computations. + -> LB.ByteString -- ^ @DK@, the output data in the format of an unlimited lazy ByteString. +pbkdf2 prf password salt iterations = LB.concat $ map LB.fromStrict $ pbkdf2_blocks prf password salt iterations diff --git a/Lazy-Pbkdf2.cabal b/Lazy-Pbkdf2.cabal --- a/Lazy-Pbkdf2.cabal +++ b/Lazy-Pbkdf2.cabal @@ -1,12 +1,12 @@ Name: Lazy-Pbkdf2 -Version: 3.0.0 +Version: 3.1.0 Author: Marcus Ofenhed Maintainer: Marcus Ofenhed License: MIT License-File: LICENSE Synopsis: Lazy PBKDF2 generator. -Description: A PBKDF2 generator that generates a lazy ByteString - of PRNG data. +Description: A PBKDF2 generator that generates either a lazy ByteString of + PRNG data or a lazy list of strict ByteStrings. Category: Cryptography Build-Type: Simple cabal-version: >= 1.10