diff --git a/src/Tahoe/SDMF/Internal/Encoding.hs b/src/Tahoe/SDMF/Internal/Encoding.hs
index 6414741681c0a38d3b430ecc20f33d65f90e9fbe..f7c5c89fa248d61b28d0600f8183533d98f49d1b 100644
--- a/src/Tahoe/SDMF/Internal/Encoding.hs
+++ b/src/Tahoe/SDMF/Internal/Encoding.hs
@@ -76,7 +76,7 @@ makeShare shareSequenceNumber shareIV shareRequiredShares shareTotalShares share
decode :: (MonadFail m, MonadIO m) => Reader -> [(Word16, Share)] -> m LB.ByteString
decode _ [] = fail "Cannot decode with no shares"
decode _ s@((_, Share{shareRequiredShares, shareTotalShares, shareSegmentSize}) : shares)
- | length shares < fromIntegral shareRequiredShares = fail $ "got " <> show (length shares) <> " shares, required " <> show shareRequiredShares
+ | length s < fromIntegral shareRequiredShares = fail $ "got " <> show (length shares) <> " shares, required " <> show shareRequiredShares
| otherwise = do
ciphertext <- liftIO $ zunfec (fromIntegral shareRequiredShares) (fromIntegral shareTotalShares) (take (fromIntegral shareRequiredShares) blocks)
pure . LB.take (fromIntegral shareSegmentSize) . LB.fromStrict $ ciphertext
diff --git a/src/Tahoe/SDMF/Internal/Keys.hs b/src/Tahoe/SDMF/Internal/Keys.hs
index f82a31608eb0adc873e1cd70f902f5e4433e068b..2617bb4efe65ad2bc5ab7bc8423bbe47647f4b76 100644
--- a/src/Tahoe/SDMF/Internal/Keys.hs
+++ b/src/Tahoe/SDMF/Internal/Keys.hs
@@ -8,14 +8,17 @@ import Prelude hiding (Read)
import Control.Monad (when)
import Crypto.Cipher.AES (AES128)
-import Crypto.Cipher.Types (BlockCipher (ctrCombine), Cipher (cipherInit, cipherKeySize), IV, KeySizeSpecifier (KeySizeFixed), nullIV)
-import Crypto.Error (maybeCryptoError)
+import Crypto.Cipher.Types (BlockCipher (ctrCombine), Cipher (cipherInit, cipherKeySize), IV, KeySizeSpecifier (KeySizeFixed), makeIV, nullIV)
+import Crypto.Error (CryptoFailable (CryptoPassed), maybeCryptoError)
import qualified Crypto.PubKey.RSA as RSA
import Crypto.Random (MonadRandom)
import Data.ASN1.BinaryEncoding (DER (DER))
import Data.ASN1.Encoding (ASN1Encoding (encodeASN1), decodeASN1')
import Data.ASN1.Types (ASN1 (End, IntVal, Null, OID, OctetString, Start), ASN1ConstructionType (Sequence), ASN1Object (fromASN1, toASN1))
import Data.Bifunctor (Bifunctor (first))
+import Data.Binary (Binary (get, put))
+import Data.Binary.Get (getByteString)
+import Data.Binary.Put (putByteString)
import qualified Data.ByteArray as ByteArray
import qualified Data.ByteString as B
import Data.ByteString.Base32 (encodeBase32Unpadded)
@@ -43,6 +46,13 @@ newtype Signature = Signature {unSignature :: RSA.PrivateKey}
data Write = Write {unWrite :: AES128, writeKeyBytes :: ByteArray.ScrubbedBytes}
+instance Binary Write where
+ put = putByteString . ByteArray.convert . writeKeyBytes
+ get = do
+ writeKeyBytes <- ByteArray.convert <$> getByteString 16
+ let (CryptoPassed unWrite) = cipherInit writeKeyBytes
+ pure Write{..}
+
instance Show Write where
show (Write _ bs) = T.unpack $ T.concat ["<WriteKey ", encodeBase32Unpadded (ByteArray.convert bs), ">"]
diff --git a/test/Spec.hs b/test/Spec.hs
index df71c875c4f39c6e82dbc66b52bdd3df7324827b..7f2bd9f947888afcc65427d2db54a5dd99282516 100644
--- a/test/Spec.hs
+++ b/test/Spec.hs
@@ -11,6 +11,7 @@ import Hedgehog (
tripping,
)
+import Control.Monad (when)
import Control.Monad.IO.Class (liftIO)
import Crypto.Cipher.Types (makeIV)
import Data.ASN1.BinaryEncoding (DER (DER))
@@ -19,7 +20,7 @@ import qualified Data.Binary as Binary
import Data.Binary.Get (ByteOffset)
import qualified Data.ByteArray as ByteArray
import qualified Data.ByteString as B
-import Data.ByteString.Base32 (encodeBase32Unpadded)
+import Data.ByteString.Base32 (decodeBase32Unpadded, encodeBase32Unpadded)
import qualified Data.ByteString.Lazy as LB
import qualified Data.Text as T
import Generators (encodingParameters, genRSAKeys, shareHashChains, shares)
@@ -171,8 +172,33 @@ tests =
Keys.deriveDataKey iv readKey
plaintext <- forAll $ LB.fromStrict <$> Gen.bytes (Range.exponential 1 1024)
tripping plaintext (Tahoe.SDMF.encrypt dataKey iv) (Just . Tahoe.SDMF.decrypt dataKey iv)
+ , testCase "Recover plaintext from a known-correct slot" $ do
+ s0 <- liftIO $ Binary.decode <$> (LB.readFile "test/data/3of10.0" >>= readShareFromBucket)
+ s6 <- liftIO $ Binary.decode <$> (LB.readFile "test/data/3of10.6" >>= readShareFromBucket)
+ s9 <- liftIO $ Binary.decode <$> (LB.readFile "test/data/3of10.9" >>= readShareFromBucket)
+
+ let (Right writeKey) = Binary.decode . LB.fromStrict <$> decodeBase32Unpadded "vdv6pcqkblsguvkagrblr3gopu"
+ (Just readerReadKey) = Keys.deriveReadKey writeKey
+ readerVerificationKeyHash = "junk"
+ reader = Tahoe.SDMF.Reader{..}
+ ciphertext <- Tahoe.SDMF.decode reader [(0, s0), (6, s6), (9, s9)]
+ let (Just dataKey) = Keys.deriveDataKey (Tahoe.SDMF.shareIV s0) readerReadKey
+ plaintext = Tahoe.SDMF.decrypt dataKey (Tahoe.SDMF.shareIV s0) ciphertext
+
+ print plaintext
+ pure ()
]
+readShareFromBucket :: MonadFail m => LB.ByteString -> m LB.ByteString
+readShareFromBucket bucket =
+ let withoutPrefix = LB.drop (32 + 20 + 32 + 8 + 8 + 368) bucket
+ dataSize = LB.length withoutPrefix - 4
+ shareData = LB.take dataSize withoutPrefix
+ suffix = LB.drop dataSize withoutPrefix
+ in do
+ when (suffix /= "\0\0\0\0") (fail "Cannot account for extra leases")
+ pure shareData
+
{- | Load a known-correct SDMF bucket and assert that bytes in the slot it
contains deserializes to a Share and then serializes back to the same bytes
@@ -187,13 +213,14 @@ knownCorrectRoundTrip n = do
-- having to parse the prefix, we assert that the suffix is a
-- predictable size.
bucket <- LB.readFile ("test/data/3of10." <> show n)
- let withoutPrefix = LB.drop (32 + 20 + 32 + 8 + 8 + 368) bucket
- dataSize = LB.length withoutPrefix - 4
- shareData = LB.take dataSize withoutPrefix
- suffix = LB.drop dataSize withoutPrefix
-
- -- Our assumption about the data we're working on...
- assertEqual "Cannot account for extra leases" suffix "\0\0\0\0"
+ shareData <- readShareFromBucket bucket
+ -- let withoutPrefix = LB.drop (32 + 20 + 32 + 8 + 8 + 368) bucket
+ -- dataSize = LB.length withoutPrefix - 4
+ -- shareData = LB.take dataSize withoutPrefix
+ -- suffix = LB.drop dataSize withoutPrefix
+
+ -- -- Our assumption about the data we're working on...
+ -- assertEqual "Cannot account for extra leases" suffix "\0\0\0\0"
let decoded = decode' shareData
let encoded = (Binary.encode :: Tahoe.SDMF.Share -> LB.ByteString) <$> decoded