blob: 2577c6b057780ffc3a881303eb5fd1eeee75b059 (
plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
|
{-# LANGUAGE FlexibleInstances, OverloadedStrings #-}
module Hash where
import Types
import qualified Data.ByteString as B
import qualified Data.ByteString.Char8 as C8
import qualified Crypto.Hash as H
class Hashable a where
hash :: a -> Hash
instance Hashable B.ByteString where
-- Encodes the SHA256 using base16 format
hash = Hash SHA256 . Val . C8.pack . show . sha256
instance Hashable Val where
hash (Val v) = hash v
instance Hashable Hash where
hash = id
sha256 :: B.ByteString -> H.Digest H.SHA256
sha256 = H.hash
-- | A value tagged with a ByteString describing the type of value.
-- This is hashed by hashing the concacenation of the hash of the
-- bytestring and the hash of the value. This way, items of different types
-- but with the same internal content will hash differently. For example,
-- a Seen "foo" and a Entered "foo" should not hash the same.
data Tagged a = Tagged B.ByteString a
instance Hashable a => Hashable (Tagged a) where
hash (Tagged b a) = hash [hash b, hash a]
instance Hashable a => Hashable (Activity a) where
hash (Activity a mp s) = hash $ Tagged "Activity"
[hash a, hash mp, hash s]
instance Hashable a => Hashable (Proto a) where
hash (Proto a) = hash $ Tagged "Proto" a
hash (Rejected a) = hash $ Tagged "Rejected" (hash a)
instance Hashable Entered where
hash v = hash $ Tagged "Entered"
[hash (enteredData v), hash (echoData v)]
instance Hashable Seen where
hash v = hash $ Tagged "Seen" [hash (seenData v)]
instance Hashable Signature where
hash (Ed25519 s) = hash $ Tagged "Ed25519" s
hash Unsigned = hash $ Tagged "Unsigned" (mempty :: B.ByteString)
-- | Hash a list of hashes by hashing the concacenation of the hashes.
instance Hashable [Hash] where
hash = hash . B.concat . map (val . hashValue)
-- | Hash empty string for Nothing
instance Hashable v => Hashable (Maybe v) where
hash Nothing = hash (mempty :: B.ByteString)
hash (Just v) = hash v
|