From: Matt Corallo <git@bluematt.me>
Date: Wed, 29 Aug 2018 18:31:50 +0000 (-0400)
Subject: Correct excess-data handling in ChannelAnnouncement verif in Router
X-Git-Tag: v0.0.12~334^2~5
X-Git-Url: http://git.bitcoin.ninja/index.cgi?a=commitdiff_plain;h=0881bf4b7460921eff425f0b4833b994922064a5;p=rust-lightning

Correct excess-data handling in ChannelAnnouncement verif in Router
---

diff --git a/src/ln/channel.rs b/src/ln/channel.rs
index b59379aa7..f890f0396 100644
--- a/src/ln/channel.rs
+++ b/src/ln/channel.rs
@@ -2303,6 +2303,7 @@ impl Channel {
 			node_id_2: if were_node_one { self.get_their_node_id() } else { our_node_id },
 			bitcoin_key_1: if were_node_one { our_bitcoin_key } else { self.their_funding_pubkey.unwrap() },
 			bitcoin_key_2: if were_node_one { self.their_funding_pubkey.unwrap() } else { our_bitcoin_key },
+			excess_data: Vec::new(),
 		};
 
 		let msghash = Message::from_slice(&Sha256dHash::from_data(&msg.encode()[..])[..]).unwrap();
diff --git a/src/ln/msgs.rs b/src/ln/msgs.rs
index 6a005f528..00095cd15 100644
--- a/src/ln/msgs.rs
+++ b/src/ln/msgs.rs
@@ -352,6 +352,7 @@ pub struct UnsignedChannelAnnouncement {
 	pub node_id_2: PublicKey,
 	pub bitcoin_key_1: PublicKey,
 	pub bitcoin_key_2: PublicKey,
+	pub excess_data: Vec<u8>,
 }
 #[derive(PartialEq, Clone)]
 pub struct ChannelAnnouncement {
@@ -1369,6 +1370,8 @@ impl MsgDecodable for UnsignedChannelAnnouncement {
 		}
 		let start = features.encoded_len();
 		let secp_ctx = Secp256k1::without_caps();
+		let mut excess_data = Vec::with_capacity(v.len() - start - 172);
+		excess_data.extend_from_slice(&v[start + 172..]);
 		Ok(Self {
 			features,
 			chain_hash: deserialize(&v[start..start + 32]).unwrap(),
@@ -1377,13 +1380,14 @@ impl MsgDecodable for UnsignedChannelAnnouncement {
 			node_id_2: secp_pubkey!(&secp_ctx, &v[start + 73..start + 106]),
 			bitcoin_key_1: secp_pubkey!(&secp_ctx, &v[start + 106..start + 139]),
 			bitcoin_key_2: secp_pubkey!(&secp_ctx, &v[start + 139..start + 172]),
+			excess_data,
 		})
 	}
 }
 impl MsgEncodable for UnsignedChannelAnnouncement {
 	fn encode(&self) -> Vec<u8> {
 		let features = self.features.encode();
-		let mut res = Vec::with_capacity(172 + features.len());
+		let mut res = Vec::with_capacity(172 + features.len() + self.excess_data.len());
 		res.extend_from_slice(&features[..]);
 		res.extend_from_slice(&self.chain_hash[..]);
 		res.extend_from_slice(&byte_utils::be64_to_array(self.short_channel_id));
@@ -1391,6 +1395,7 @@ impl MsgEncodable for UnsignedChannelAnnouncement {
 		res.extend_from_slice(&self.node_id_2.serialize());
 		res.extend_from_slice(&self.bitcoin_key_1.serialize());
 		res.extend_from_slice(&self.bitcoin_key_2.serialize());
+		res.extend_from_slice(&self.excess_data[..]);
 		res
 	}
 }
diff --git a/src/ln/router.rs b/src/ln/router.rs
index 1ca55fa26..1f713f69d 100644
--- a/src/ln/router.rs
+++ b/src/ln/router.rs
@@ -263,7 +263,7 @@ impl RoutingMessageHandler for Router {
 		add_channel_to_node!(msg.contents.node_id_1);
 		add_channel_to_node!(msg.contents.node_id_2);
 
-		Ok(!msg.contents.features.supports_unknown_bits())
+		Ok(msg.contents.excess_data.is_empty() && !msg.contents.features.supports_unknown_bits())
 	}
 
 	fn handle_htlc_fail_channel_update(&self, update: &msgs::HTLCFailChannelUpdate) {