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
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
|
module Pairing (
PairingService(..),
PairingState(..),
PairingResult(..),
pairingRequest,
) where
import Control.Monad.Except
import Control.Monad.Reader
import Crypto.Random
import Data.Bits
import Data.ByteArray (Bytes, convert)
import qualified Data.ByteArray as BA
import qualified Data.ByteString.Char8 as BC
import Data.Maybe
import qualified Data.Text as T
import Data.Typeable
import Data.Word
import Identity
import Network
import Service
import State
import Storage
data PairingService a = PairingRequest RefDigest
| PairingResponse Bytes
| PairingRequestNonce Bytes
| PairingAccept a
| PairingDecline
data PairingState a = NoPairing
| OurRequest Bytes
| OurRequestConfirm (Maybe a)
| OurRequestReady
| PeerRequest Bytes RefDigest
| PeerRequestConfirm
| PairingDone
| PairingFailed
class (Typeable a, Storable a) => PairingResult a where
pairingServiceID :: proxy a -> ServiceID
pairingHookRequest :: ServiceHandler (PairingService a) ()
pairingHookResponse :: String -> ServiceHandler (PairingService a) ()
pairingHookRequestNonce :: String -> ServiceHandler (PairingService a) ()
pairingHookRequestNonceFailed :: ServiceHandler (PairingService a) ()
pairingHookConfirm :: a -> ServiceHandler (PairingService a) (Maybe a)
pairingHookAccept :: a -> ServiceHandler (PairingService a) ()
instance Storable a => Storable (PairingService a) where
store' (PairingRequest x) = storeRec $ storeBinary "request" x
store' (PairingResponse x) = storeRec $ storeBinary "response" x
store' (PairingRequestNonce x) = storeRec $ storeBinary "reqnonce" x
store' (PairingAccept x) = store' x
store' (PairingDecline) = storeRec $ storeText "decline" ""
load' = do
res <- loadRec $ do
(req :: Maybe Bytes) <- loadMbBinary "request"
rsp <- loadMbBinary "response"
rnonce <- loadMbBinary "reqnonce"
(decline :: Maybe T.Text) <- loadMbText "decline"
return $ catMaybes
[ PairingRequest <$> (refDigestFromByteString =<< req)
, PairingResponse <$> rsp
, PairingRequestNonce <$> rnonce
, const PairingDecline <$> decline
]
case res of
x:_ -> return x
[] -> PairingAccept <$> load'
instance PairingResult a => Service (PairingService a) where
serviceID _ = pairingServiceID @a Proxy
type ServiceState (PairingService a) = PairingState a
emptyServiceState _ = NoPairing
serviceHandler spacket = ((,fromStored spacket) <$> svcGet) >>= \case
(NoPairing, PairingRequest confirm) -> do
pairingHookRequest
nonce <- liftIO $ getRandomBytes 32
svcSet $ PeerRequest nonce confirm
replyPacket $ PairingResponse nonce
(NoPairing, _) -> return ()
(OurRequest nonce, PairingResponse pnonce) -> do
peer <- asks $ svcPeerIdentity
self <- maybe (throwError "failed to validate own identity") return .
validateIdentity . lsIdentity . fromStored =<< svcGetLocal
pairingHookResponse $ confirmationNumber $ nonceDigest self peer nonce pnonce
svcSet $ OurRequestConfirm Nothing
replyPacket $ PairingRequestNonce nonce
(OurRequest _, _) -> do
svcSet $ PairingFailed
replyPacket PairingDecline
(OurRequestConfirm _, PairingAccept x) -> do
(svcSet . OurRequestConfirm =<< pairingHookConfirm x) `catchError` \_ -> do
svcSet $ PairingFailed
replyPacket PairingDecline
(OurRequestConfirm _, _) -> do
svcSet $ PairingFailed
replyPacket PairingDecline
(OurRequestReady, PairingAccept x) -> do
pairingHookAccept x `catchError` \_ -> do
svcSet $ PairingFailed
replyPacket PairingDecline
(OurRequestReady, _) -> do
svcSet $ PairingFailed
replyPacket PairingDecline
(PeerRequest nonce dgst, PairingRequestNonce pnonce) -> do
peer <- asks $ svcPeerIdentity
self <- maybe (throwError "failed to verify own identity") return .
validateIdentity . lsIdentity . fromStored =<< svcGetLocal
if dgst == nonceDigest peer self pnonce BA.empty
then do pairingHookRequestNonce $ confirmationNumber $ nonceDigest peer self pnonce nonce
svcSet PeerRequestConfirm
else do pairingHookRequestNonceFailed
svcSet PairingFailed
replyPacket PairingDecline
(PeerRequest _ _, _) -> do
svcSet $ PairingFailed
replyPacket PairingDecline
(PeerRequestConfirm, _) -> do
svcSet $ PairingFailed
replyPacket PairingDecline
(PairingDone, _) -> return ()
(PairingFailed, _) -> return ()
nonceDigest :: UnifiedIdentity -> UnifiedIdentity -> Bytes -> Bytes -> RefDigest
nonceDigest id1 id2 nonce1 nonce2 = hashToRefDigest $ serializeObject $ Rec
[ (BC.pack "id", RecRef $ storedRef $ idData id1)
, (BC.pack "id", RecRef $ storedRef $ idData id2)
, (BC.pack "nonce", RecBinary $ convert nonce1)
, (BC.pack "nonce", RecBinary $ convert nonce2)
]
confirmationNumber :: RefDigest -> String
confirmationNumber dgst = let (a:b:c:d:_) = map fromIntegral $ BA.unpack dgst :: [Word32]
str = show $ ((a `shift` 24) .|. (b `shift` 16) .|. (c `shift` 8) .|. d) `mod` (10 ^ len)
in replicate (len - length str) '0' ++ str
where len = 6
pairingRequest :: forall a m proxy. (PairingResult a, MonadIO m, MonadError String m) => proxy a -> UnifiedIdentity -> Peer -> m ()
pairingRequest _ self peer = do
nonce <- liftIO $ getRandomBytes 32
pid <- peerIdentity peer >>= \case
PeerIdentityFull pid -> return pid
_ -> throwError "incomplete peer identity"
sendToPeerWith @(PairingService a) self peer $ \case
NoPairing -> return (Just $ PairingRequest (nonceDigest self pid nonce BA.empty), OurRequest nonce)
_ -> throwError "alredy in progress"
|