node: Implement signed refs

Signed-off-by: Alexis Sellier <self@cloudhead.io>

node/src/protocol/message.rs

@@ -7,6 +7,7 @@ use crate::crypto;
 use crate::identity::{ProjId, UserId};
 use crate::protocol::{Context, NodeId, Timestamp, PROTOCOL_VERSION};
 use crate::storage;
+use crate::storage::refs::SignedRefs;
 
 /// Message envelope. All messages sent over the network are wrapped in this type.
 #[derive(Debug, Serialize, Deserialize)]
@@ -104,9 +105,7 @@ pub enum Message {
         /// User signing.
         user: UserId,
         /// Updated refs.
-        refs: storage::Refs,
-        /// Signature over the refs.
-        signature: crypto::Signature,
+        refs: SignedRefs<crypto::Unverified>,
     },
 }
 

node/src/protocol/peer.rs

@@ -194,18 +194,8 @@ impl Peer {
                     }));
                 }
             }
-            (
-                PeerState::Negotiated { git, .. },
-                Message::RefsUpdate {
-                    proj,
-                    user,
-                    refs,
-                    signature,
-                },
-            ) => {
-                let bytes = serde_json::to_vec(&refs).unwrap();
-
-                if user.verify(&signature, &bytes).is_ok() {
+            (PeerState::Negotiated { git, .. }, Message::RefsUpdate { proj, user, refs }) => {
+                if refs.verified(&user).is_ok() {
                     // TODO: Buffer/throttle fetches.
                     // TODO: Also pass the updated refs so that we can check whether
                     // we need to fetch or not.