Require any Router also implements MessageRouter
[rust-lightning] / lightning / src / util / scid_utils.rs
index 79ef415c7b24f39e0034ad0d299ef8492172fd71..fbbcc69a133e0966e8bd937d1838ac8dc4fd5c17 100644 (file)
@@ -63,17 +63,19 @@ pub fn scid_from_parts(block: u64, tx_index: u64, vout_index: u64) -> Result<u64
 /// LDK has multiple reasons to generate fake short channel ids:
 /// 1) outbound SCID aliases we use for private channels
 /// 2) phantom node payments, to get an scid for the phantom node's phantom channel
+/// 3) payments intended to be intercepted will route using a fake scid (this is typically used so
+///    the forwarding node can open a JIT channel to the next hop)
 pub(crate) mod fake_scid {
-       use bitcoin::hash_types::BlockHash;
-       use bitcoin::hashes::hex::FromHex;
-       use chain::keysinterface::{Sign, KeysInterface};
-       use util::chacha20::ChaCha20;
-       use util::scid_utils;
+       use bitcoin::blockdata::constants::ChainHash;
+       use bitcoin::network::constants::Network;
+       use crate::sign::EntropySource;
+       use crate::util::chacha20::ChaCha20;
+       use crate::util::scid_utils;
 
        use core::convert::TryInto;
        use core::ops::Deref;
 
-       const TEST_SEGWIT_ACTIVATION_HEIGHT: u32 = 0;
+       const TEST_SEGWIT_ACTIVATION_HEIGHT: u32 = 1;
        const MAINNET_SEGWIT_ACTIVATION_HEIGHT: u32 = 481_824;
        const MAX_TX_INDEX: u32 = 2_500;
        const MAX_NAMESPACES: u8 = 8; // We allocate 3 bits for the namespace identifier.
@@ -91,6 +93,7 @@ pub(crate) mod fake_scid {
        pub(crate) enum Namespace {
                Phantom,
                OutboundAlias,
+               Intercept
        }
 
        impl Namespace {
@@ -98,15 +101,15 @@ pub(crate) mod fake_scid {
                /// between segwit activation and the current best known height, and the tx index and output
                /// index are also selected from a "reasonable" range. We add this logic because it makes it
                /// non-obvious at a glance that the scid is fake, e.g. if it appears in invoice route hints.
-               pub(crate) fn get_fake_scid<Signer: Sign, K: Deref>(&self, highest_seen_blockheight: u32, genesis_hash: &BlockHash, fake_scid_rand_bytes: &[u8; 32], keys_manager: &K) -> u64
-                       where K::Target: KeysInterface<Signer = Signer>,
+               pub(crate) fn get_fake_scid<ES: Deref>(&self, highest_seen_blockheight: u32, chain_hash: &ChainHash, fake_scid_rand_bytes: &[u8; 32], entropy_source: &ES) -> u64
+                       where ES::Target: EntropySource,
                {
                        // Ensure we haven't created a namespace that doesn't fit into the 3 bits we've allocated for
                        // namespaces.
                        assert!((*self as u8) < MAX_NAMESPACES);
-                       let rand_bytes = keys_manager.get_secure_random_bytes();
+                       let rand_bytes = entropy_source.get_secure_random_bytes();
 
-                       let segwit_activation_height = segwit_activation_height(genesis_hash);
+                       let segwit_activation_height = segwit_activation_height(chain_hash);
                        let mut blocks_since_segwit_activation = highest_seen_blockheight.saturating_sub(segwit_activation_height);
 
                        // We want to ensure that this fake channel won't conflict with any transactions we haven't
@@ -141,52 +144,66 @@ pub(crate) mod fake_scid {
                }
        }
 
-       fn segwit_activation_height(genesis: &BlockHash) -> u32 {
-               const MAINNET_GENESIS_STR: &'static str = "000000000019d6689c085ae165831e934ff763ae46a2a6c172b3f1b60a8ce26f";
-               if BlockHash::from_hex(MAINNET_GENESIS_STR).unwrap() == *genesis {
+       fn segwit_activation_height(chain_hash: &ChainHash) -> u32 {
+               if *chain_hash == ChainHash::using_genesis_block(Network::Bitcoin) {
                        MAINNET_SEGWIT_ACTIVATION_HEIGHT
                } else {
                        TEST_SEGWIT_ACTIVATION_HEIGHT
                }
        }
 
-       /// 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 {
+       /// Returns whether the given fake scid falls into the phantom namespace.
+       pub fn is_valid_phantom(fake_scid_rand_bytes: &[u8; 32], scid: u64, chain_hash: &ChainHash) -> 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
+               block_height >= segwit_activation_height(chain_hash)
+                       && valid_vout == scid_utils::vout_from_scid(&scid) as u8
+       }
+
+       /// Returns whether the given fake scid falls into the intercept namespace.
+       pub fn is_valid_intercept(fake_scid_rand_bytes: &[u8; 32], scid: u64, chain_hash: &ChainHash) -> bool {
+               let block_height = scid_utils::block_from_scid(&scid);
+               let tx_index = scid_utils::tx_index_from_scid(&scid);
+               let namespace = Namespace::Intercept;
+               let valid_vout = namespace.get_encrypted_vout(block_height, tx_index, fake_scid_rand_bytes);
+               block_height >= segwit_activation_height(chain_hash)
+                       && valid_vout == scid_utils::vout_from_scid(&scid) as u8
        }
 
        #[cfg(test)]
        mod tests {
-               use bitcoin::blockdata::constants::genesis_block;
+               use bitcoin::blockdata::constants::ChainHash;
                use bitcoin::network::constants::Network;
-               use util::scid_utils::fake_scid::{is_valid_phantom, MAINNET_SEGWIT_ACTIVATION_HEIGHT, MAX_TX_INDEX, MAX_NAMESPACES, Namespace, NAMESPACE_ID_BITMASK, segwit_activation_height, TEST_SEGWIT_ACTIVATION_HEIGHT};
-               use util::scid_utils;
-               use util::test_utils;
-               use sync::Arc;
+               use crate::util::scid_utils::fake_scid::{is_valid_intercept, is_valid_phantom, MAINNET_SEGWIT_ACTIVATION_HEIGHT, MAX_TX_INDEX, MAX_NAMESPACES, Namespace, NAMESPACE_ID_BITMASK, segwit_activation_height, TEST_SEGWIT_ACTIVATION_HEIGHT};
+               use crate::util::scid_utils;
+               use crate::util::test_utils;
+               use crate::sync::Arc;
 
                #[test]
                fn namespace_identifier_is_within_range() {
                        let phantom_namespace = Namespace::Phantom;
                        assert!((phantom_namespace as u8) < MAX_NAMESPACES);
                        assert!((phantom_namespace as u8) <= NAMESPACE_ID_BITMASK);
+
+                       let intercept_namespace = Namespace::Intercept;
+                       assert!((intercept_namespace as u8) < MAX_NAMESPACES);
+                       assert!((intercept_namespace as u8) <= NAMESPACE_ID_BITMASK);
                }
 
                #[test]
                fn test_segwit_activation_height() {
-                       let mainnet_genesis = genesis_block(Network::Bitcoin).header.block_hash();
+                       let mainnet_genesis = ChainHash::using_genesis_block(Network::Bitcoin);
                        assert_eq!(segwit_activation_height(&mainnet_genesis), MAINNET_SEGWIT_ACTIVATION_HEIGHT);
 
-                       let testnet_genesis = genesis_block(Network::Testnet).header.block_hash();
+                       let testnet_genesis = ChainHash::using_genesis_block(Network::Testnet);
                        assert_eq!(segwit_activation_height(&testnet_genesis), TEST_SEGWIT_ACTIVATION_HEIGHT);
 
-                       let signet_genesis = genesis_block(Network::Signet).header.block_hash();
+                       let signet_genesis = ChainHash::using_genesis_block(Network::Signet);
                        assert_eq!(segwit_activation_height(&signet_genesis), TEST_SEGWIT_ACTIVATION_HEIGHT);
 
-                       let regtest_genesis = genesis_block(Network::Regtest).header.block_hash();
+                       let regtest_genesis = ChainHash::using_genesis_block(Network::Regtest);
                        assert_eq!(segwit_activation_height(&regtest_genesis), TEST_SEGWIT_ACTIVATION_HEIGHT);
                }
 
@@ -194,16 +211,29 @@ pub(crate) mod fake_scid {
                fn test_is_valid_phantom() {
                        let namespace = Namespace::Phantom;
                        let fake_scid_rand_bytes = [0; 32];
+                       let testnet_genesis = ChainHash::using_genesis_block(Network::Testnet);
+                       let valid_encrypted_vout = namespace.get_encrypted_vout(0, 0, &fake_scid_rand_bytes);
+                       let valid_fake_scid = scid_utils::scid_from_parts(1, 0, valid_encrypted_vout as u64).unwrap();
+                       assert!(is_valid_phantom(&fake_scid_rand_bytes, valid_fake_scid, &testnet_genesis));
+                       let invalid_fake_scid = scid_utils::scid_from_parts(1, 0, 12).unwrap();
+                       assert!(!is_valid_phantom(&fake_scid_rand_bytes, invalid_fake_scid, &testnet_genesis));
+               }
+
+               #[test]
+               fn test_is_valid_intercept() {
+                       let namespace = Namespace::Intercept;
+                       let fake_scid_rand_bytes = [0; 32];
+                       let testnet_genesis = ChainHash::using_genesis_block(Network::Testnet);
                        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_phantom(&fake_scid_rand_bytes, valid_fake_scid));
-                       let invalid_fake_scid = scid_utils::scid_from_parts(0, 0, 12).unwrap();
-                       assert!(!is_valid_phantom(&fake_scid_rand_bytes, invalid_fake_scid));
+                       let valid_fake_scid = scid_utils::scid_from_parts(1, 0, valid_encrypted_vout as u64).unwrap();
+                       assert!(is_valid_intercept(&fake_scid_rand_bytes, valid_fake_scid, &testnet_genesis));
+                       let invalid_fake_scid = scid_utils::scid_from_parts(1, 0, 12).unwrap();
+                       assert!(!is_valid_intercept(&fake_scid_rand_bytes, invalid_fake_scid, &testnet_genesis));
                }
 
                #[test]
                fn test_get_fake_scid() {
-                       let mainnet_genesis = genesis_block(Network::Bitcoin).header.block_hash();
+                       let mainnet_genesis = ChainHash::using_genesis_block(Network::Bitcoin);
                        let seed = [0; 32];
                        let fake_scid_rand_bytes = [1; 32];
                        let keys_manager = Arc::new(test_utils::TestKeysInterface::new(&seed, Network::Testnet));