diff options
| -rw-r--r-- | src/Codec/Crypto/HKDF.hs | 29 | ||||
| -rw-r--r-- | src/Types.hs | 8 | ||||
| -rw-r--r-- | tests/Codec/Crypto/HKDFTests.hs | 29 |
3 files changed, 56 insertions, 10 deletions
diff --git a/src/Codec/Crypto/HKDF.hs b/src/Codec/Crypto/HKDF.hs index 8e81fd1..1c1dbda 100644 --- a/src/Codec/Crypto/HKDF.hs +++ b/src/Codec/Crypto/HKDF.hs @@ -13,8 +13,8 @@ -- the License. module Codec.Crypto.HKDF - ( Salt(Salt), SecretKey(SecretKey), noSalt - , extract + ( AssociatedData(AssociatedData), Salt(Salt), SecretKey(SecretKey), noSalt + , extract, expand ) where import qualified Data.ByteString as ByteString @@ -27,7 +27,8 @@ import Unsafe.Coerce (unsafeCoerce) import Data.Digest.Internal (Algorithm(Algorithm)) import Internal.Digest (evpMaxMDSize) import Internal.HKDF -import Types (Salt(Salt), SecretKey(SecretKey), noSalt) +import Types + (AssociatedData(AssociatedData), Salt(Salt), SecretKey(SecretKey), noSalt) -- | Computes an HKDF pseudorandom key (PRK) as specified by RFC 5869. extract :: Algorithm -> Salt -> SecretKey -> SecretKey @@ -46,6 +47,22 @@ extract (Algorithm md) (Salt salt) (SecretKey secret) = (asCUCharBuf pSalt) (fromIntegral saltLen) outLen <- fromIntegral <$> peek pOutLen SecretKey <$> ByteString.packCStringLen (pOutKey, outLen) - where - asCUCharBuf :: Ptr CChar -> Ptr CUChar - asCUCharBuf = unsafeCoerce + +-- | Computes HKDF output key material (OKM) as specified by RFC 5869. +expand :: Algorithm -> AssociatedData -> Int -> SecretKey -> SecretKey +expand (Algorithm md) (AssociatedData info) outLen (SecretKey secret) = + unsafeLocalState $ + allocaArray outLen $ \pOutKey -> do + -- @HKDF_expand@ won't mutate @secret@ or @info@, so the sharing inherent + -- in 'ByteString.unsafeUseAsCStringLen' is fine. + ByteString.unsafeUseAsCStringLen secret $ \(pSecret, secretLen) -> + ByteString.unsafeUseAsCStringLen info $ \(pInfo, infoLen) -> + hkdfExpand + (asCUCharBuf pOutKey) (fromIntegral outLen) + md + (asCUCharBuf pSecret) (fromIntegral secretLen) + (asCUCharBuf pInfo) (fromIntegral infoLen) + SecretKey <$> ByteString.packCStringLen (pOutKey, outLen) + +asCUCharBuf :: Ptr CChar -> Ptr CUChar +asCUCharBuf = unsafeCoerce diff --git a/src/Types.hs b/src/Types.hs index 6b430c2..3c0f350 100644 --- a/src/Types.hs +++ b/src/Types.hs @@ -13,13 +13,19 @@ -- the License. module Types - ( Salt(Salt), noSalt + ( AssociatedData(AssociatedData) + , Salt(Salt), noSalt , SecretKey(SecretKey) ) where import Data.ByteString (ByteString) import qualified Data.ByteString as ByteString +-- | Context or application-specific information. Equality comparisons on this +-- type are variable-time. +newtype AssociatedData = AssociatedData ByteString + deriving (Eq, Ord, Show) + -- | A salt. Equality comparisons on this type are variable-time. newtype Salt = Salt ByteString deriving (Eq, Ord, Show) diff --git a/tests/Codec/Crypto/HKDFTests.hs b/tests/Codec/Crypto/HKDFTests.hs index 995518c..b3b2a28 100644 --- a/tests/Codec/Crypto/HKDFTests.hs +++ b/tests/Codec/Crypto/HKDFTests.hs @@ -23,7 +23,7 @@ import qualified Data.ByteString.Char8 as ByteString.Char8 import Test.Tasty (TestTree, testGroup) import Test.Tasty.HUnit ((@?=), testCase) -import Codec.Crypto.HKDF (Salt(Salt), SecretKey(SecretKey), noSalt) +import Codec.Crypto.HKDF (AssociatedData(AssociatedData), Salt(Salt), SecretKey(SecretKey), noSalt) import qualified Codec.Crypto.HKDF as HKDF import Data.Digest (sha1, sha256) @@ -36,41 +36,64 @@ testRFC5869 = testGroup "RFC 5869 examples" sha256 (SecretKey $ ByteString.replicate 22 0x0b) (Salt $ ByteString.pack [0x00 .. 0x0c]) + (AssociatedData $ ByteString.pack [0xf0 .. 0xf9]) + 42 (SecretKey $ hex "077709362c2e32df0ddc3f0dc47bba6390b6c73bb50f9c3122ec844ad7c2b3e5") + (SecretKey $ hex "3cb25f25faacd57a90434f64d0362f2a2d2d0a90cf1a5a4c5db02d56ecc4c5bf34007208d5b887185865") , t "test case 2" sha256 (SecretKey $ ByteString.pack [0x00 .. 0x4f]) (Salt $ ByteString.pack [0x60 .. 0xaf]) + (AssociatedData $ ByteString.pack [0xb0 .. 0xff]) + 82 (SecretKey $ hex "06a6b88c5853361a06104c9ceb35b45cef760014904671014a193f40c15fc244") + (SecretKey $ hex "b11e398dc80327a1c8e7f78c596a49344f012eda2d4efad8a050cc4c19afa97c59045a99cac7827271cb41c65e590e09da3275600c2f09b8367793a9aca3db71cc30c58179ec3e87c14c01d5c1f3434f1d87") , t "test case 3" sha256 (SecretKey $ ByteString.replicate 22 0x0b) (Salt "") + (AssociatedData "") + 42 (SecretKey $ hex "19ef24a32c717b167f33a91d6f648bdf96596776afdb6377ac434c1c293ccb04") + (SecretKey $ hex "8da4e775a563c18f715f802a063c5a31b8a11f5c5ee1879ec3454e5f3c738d2d9d201395faa4b61a96c8") , t "test case 4" sha1 (SecretKey $ ByteString.replicate 11 0x0b) (Salt $ ByteString.pack [0x00 .. 0x0c]) + (AssociatedData $ ByteString.pack [0xf0 .. 0xf9]) + 42 (SecretKey $ hex "9b6c18c432a7bf8f0e71c8eb88f4b30baa2ba243") + (SecretKey $ hex "085a01ea1b10f36933068b56efa5ad81a4f14b822f5b091568a9cdd4f155fda2c22e422478d305f3f896") , t "test case 5" sha1 (SecretKey $ ByteString.pack [0x00 .. 0x4f]) (Salt $ ByteString.pack [0x60 .. 0xaf]) + (AssociatedData $ ByteString.pack [0xb0 .. 0xff]) + 82 (SecretKey $ hex "8adae09a2a307059478d309b26c4115a224cfaf6") + (SecretKey $ hex "0bd770a74d1160f7c9f12cd5912a06ebff6adcae899d92191fe4305673ba2ffe8fa3f1a4e5ad79f3f334b3b202b2173c486ea37ce3d397ed034c7f9dfeb15c5e927336d0441f4c4300e2cff0d0900b52d3b4") , t "test case 6" sha1 (SecretKey $ ByteString.replicate 22 0x0b) (Salt "") + (AssociatedData "") + 42 (SecretKey $ hex "da8c8a73c7fa77288ec6f5e7c297786aa0d32d01") + (SecretKey $ hex "0ac1af7002b3d761d1e55298da9d0506b9ae52057220a306e07b6b87e8df21d0ea00033de03984d34918") , t "test case 7" sha1 (SecretKey $ ByteString.replicate 22 0x0c) noSalt + (AssociatedData "") + 42 (SecretKey $ hex "2adccada18779e7c2077ad2eb19d3f3e731385dd") + (SecretKey $ hex "2c91117204d745f3500d636a62f64f0ab3bae548aa53d423b0d1f27ebba6f5e5673a081d70cce7acfc48") ] where - t name hash ikm salt prk = - testGroup name [testCase "extract" $ HKDF.extract hash salt ikm @?= prk] + t name hash ikm salt info len prk okm = + testGroup name [ testCase "extract" $ HKDF.extract hash salt ikm @?= prk + , testCase "expand" $ HKDF.expand hash info len prk @?= okm + ] hex :: ByteString -> ByteString hex s = |