improve documentation on HandshakeData

1 files changed, 12 insertions, 4 deletions

diff --git a/src/Network/Tox/Crypto/Transport.hs b/src/Network/Tox/Crypto/Transport.hs
index e23d1865..22a1b795 100644
--- a/src/Network/Tox/Crypto/Transport.hs
+++ b/src/Network/Tox/Crypto/Transport.hs
@@ -113,10 +113,18 @@ instance Serialize (Handshake Encrypted) where
     put (Handshake cookie n24 dta) = put cookie >> put n24 >> put dta
 
 data HandshakeData = HandshakeData
-    { baseNonce   :: Nonce24          -- ^ [24 bytes base nonce]
-    , sessionKey  :: PublicKey        -- ^ [session public key of the peer (32 bytes)]
-    , cookieHash  :: Digest SHA512    -- ^ [sha512 hash of the entire Cookie sitting outside the encrypted part]
-    , otherCookie :: Cookie Encrypted -- ^ [Other Cookie (used by the other to respond to the handshake packet)]
+    { baseNonce :: Nonce24
+    -- ^ 24 bytes base nonce, recipient uses this to encrypt packets sent to the one who sent this handshake
+    --   adding one each time, so it can double as something like an approximate packet number
+    , sessionKey :: PublicKey
+    -- ^ session public key of the peer (32 bytes)
+    -- The recipient of the handshake encrypts using this public key when sending CryptoPackets
+    , cookieHash :: Digest SHA512
+    -- ^ sha512 hash of the entire Cookie sitting outside the encrypted part
+    --  This prevents a replay attack where a new cookie is inserted into
+    --  an old valid handshake packet
+    , otherCookie :: Cookie Encrypted
+    -- ^ Other Cookie (used by the repient to respond to the handshake packet)
     }
 
 instance Sized HandshakeData where