add intercept fake_scid namespace

Author: johncantrell97

lightning/src/util/scid_utils.rs

@@ -91,6 +91,7 @@ pub(crate) mod fake_scid {
 	pub(crate) enum Namespace {
 		Phantom,
 		OutboundAlias,
+		Intercept
 	}
 
 	impl Namespace {
@@ -151,14 +152,25 @@ pub(crate) mod fake_scid {
 	}
 
 	/// Returns whether the given fake scid falls into the given namespace.
-	pub fn is_valid_phantom(fake_scid_rand_bytes: &[u8; 32], scid: u64) -> bool {
+	pub fn is_in_namespace(namespace: Namespace, fake_scid_rand_bytes: &[u8; 32], scid: u64) -> bool {
 		let block_height = scid_utils::block_from_scid(&scid);
 		let tx_index = scid_utils::tx_index_from_scid(&scid);
-		let namespace = Namespace::Phantom;
 		let valid_vout = namespace.get_encrypted_vout(block_height, tx_index, fake_scid_rand_bytes);
 		valid_vout == scid_utils::vout_from_scid(&scid) as u8
 	}
 
+	/// Returns whether the given fake scid falls into the phantom namespace.
+	pub fn is_valid_phantom(fake_scid_rand_bytes: &[u8; 32], scid: u64) -> bool {
+		is_in_namespace(Namespace::Phantom, fake_scid_rand_bytes, scid)
+	}
+
+	/// Returns whether the given fake scid falls into the intercept namespace.
+	pub fn is_valid_intercept(fake_scid_rand_bytes: &[u8; 32], scid: u64) -> bool {
+		is_in_namespace(Namespace::Intercept, fake_scid_rand_bytes, scid)
+	}
+
+
+
 	#[cfg(test)]
 	mod tests {
 		use bitcoin::blockdata::constants::genesis_block;
@@ -168,6 +180,8 @@ pub(crate) mod fake_scid {
 		use util::test_utils;
 		use sync::Arc;
 
+use crate::util::scid_utils::fake_scid::is_valid_intercept;
+
 		#[test]
 		fn namespace_identifier_is_within_range() {
 			let phantom_namespace = Namespace::Phantom;
@@ -201,6 +215,16 @@ pub(crate) mod fake_scid {
 			assert!(!is_valid_phantom(&fake_scid_rand_bytes, invalid_fake_scid));
 		}
 
+		fn test_is_valid_intercept() {
+			let namespace = Namespace::Intercept;
+			let fake_scid_rand_bytes = [0; 32];
+			let valid_encrypted_vout = namespace.get_encrypted_vout(0, 0, &fake_scid_rand_bytes);
+			let valid_fake_scid = scid_utils::scid_from_parts(0, 0, valid_encrypted_vout as u64).unwrap();
+			assert!(is_valid_intercept(&fake_scid_rand_bytes, valid_fake_scid));
+			let invalid_fake_scid = scid_utils::scid_from_parts(0, 0, 12).unwrap();
+			assert!(!is_valid_intercept(&fake_scid_rand_bytes, invalid_fake_scid));
+		}
+
 		#[test]
 		fn test_get_fake_scid() {
 			let mainnet_genesis = genesis_block(Network::Bitcoin).header.block_hash();