implement Hash function for block announce handshake

ChainSafe · Apr 1, 2022 · 41d1f45 · 41d1f45
1 parent 1fcfb7f
commit 41d1f45
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Showing 3 changed files with 15 additions and 5 deletions.
diff --git a/dot/network/block_announce.go b/dot/network/block_announce.go
@@ -147,9 +147,15 @@ func (*BlockAnnounceHandshake) Type() byte {
 	return 0
 }
 
-// Hash ...
-func (*BlockAnnounceHandshake) Hash() (common.Hash, error) {
-	return common.Hash{}, nil
+// Hash returns blake2b hash of block announce handshake.
+func (hs *BlockAnnounceHandshake) Hash() (common.Hash, error) {
+	// scale encode each extrinsic
+	encMsg, err := hs.Encode()
+	if err != nil {
+		return common.Hash{}, fmt.Errorf("cannot encode handshake: %w", err)
+	}
+
+	return common.Blake2bHash(encMsg)
 }
 
 // IsHandshake returns true

diff --git a/dot/network/gossip.go b/dot/network/gossip.go
@@ -40,7 +40,9 @@ func (g *gossip) hasSeen(msg NotificationsMessage) (bool, error) {
 	_, ok := g.seenMap[msgHash]
 	if !ok {
 		// set message to has been seen
-		g.seenMap[msgHash] = struct{}{}
+		if !msg.IsHandshake() {
+			g.seenMap[msgHash] = struct{}{}
+		}
 		return false, nil
 	}
 

diff --git a/dot/network/notifications_test.go b/dot/network/notifications_test.go
@@ -189,7 +189,9 @@ func TestCreateNotificationsMessageHandler_BlockAnnounceHandshake(t *testing.T)
 		Roles:           4,
 		BestBlockNumber: 77,
 		BestBlockHash:   common.Hash{1},
-		GenesisHash:     common.Hash{2},
+		// we are using a different genesis here, thus this
+		// handshake would be validated to be incorrect.
+		GenesisHash: common.Hash{2},
 	}
 
 	err = handler(stream, testHandshake)