From: Valentine Wallace Date: Fri, 25 Feb 2022 03:19:20 +0000 (-0500) Subject: Fix phantom malformed onion error packet X-Git-Tag: v0.0.105~5^2~2 X-Git-Url: http://git.bitcoin.ninja/index.cgi?a=commitdiff_plain;h=3faea334389a2cf92b2122a8aa464d63de21ca70;p=rust-lightning Fix phantom malformed onion error packet Ensure we fail back phantom malformed payments with an update_fail_htlc s.t. the error contains the sha256 of the onion, per LN protocol. --- diff --git a/lightning/src/ln/channelmanager.rs b/lightning/src/ln/channelmanager.rs index a6856b41..373b0a19 100644 --- a/lightning/src/ln/channelmanager.rs +++ b/lightning/src/ln/channelmanager.rs @@ -358,7 +358,7 @@ mod inbound_payment { // our payment, which we can use to decode errors or inform the user that the payment was sent. #[derive(Clone)] // See Channel::revoke_and_ack for why, tl;dr: Rust bug -enum PendingHTLCRouting { +pub(super) enum PendingHTLCRouting { Forward { onion_packet: msgs::OnionPacket, short_channel_id: u64, // This should be NonZero eventually when we bump MSRV @@ -376,8 +376,8 @@ enum PendingHTLCRouting { #[derive(Clone)] // See Channel::revoke_and_ack for why, tl;dr: Rust bug pub(super) struct PendingHTLCInfo { - routing: PendingHTLCRouting, - incoming_shared_secret: [u8; 32], + pub(super) routing: PendingHTLCRouting, + pub(super) incoming_shared_secret: [u8; 32], payment_hash: PaymentHash, pub(super) amt_to_forward: u64, pub(super) outgoing_cltv_value: u32, @@ -3043,7 +3043,12 @@ impl ChannelMana let next_hop = match onion_utils::decode_next_hop(phantom_shared_secret, &onion_packet.hop_data, onion_packet.hmac, payment_hash) { Ok(res) => res, Err(onion_utils::OnionDecodeErr::Malformed { err_msg, err_code }) => { - fail_forward!(err_msg, err_code, Vec::new(), None); + let sha256_of_onion = Sha256::hash(&onion_packet.hop_data).into_inner(); + // In this scenario, the phantom would have sent us an + // `update_fail_malformed_htlc`, meaning here we encrypt the error as + // if it came from us (the second-to-last hop) but contains the sha256 + // of the onion. + fail_forward!(err_msg, err_code, sha256_of_onion.to_vec(), None); }, Err(onion_utils::OnionDecodeErr::Relay { err_msg, err_code }) => { fail_forward!(err_msg, err_code, Vec::new(), Some(phantom_shared_secret)); diff --git a/lightning/src/ln/onion_route_tests.rs b/lightning/src/ln/onion_route_tests.rs index 4feae104..4936941e 100644 --- a/lightning/src/ln/onion_route_tests.rs +++ b/lightning/src/ln/onion_route_tests.rs @@ -12,25 +12,28 @@ //! returned errors decode to the correct thing. use chain::channelmonitor::{CLTV_CLAIM_BUFFER, LATENCY_GRACE_PERIOD_BLOCKS}; +use chain::keysinterface::{KeysInterface, Recipient}; use ln::{PaymentHash, PaymentSecret}; -use ln::channelmanager::{HTLCForwardInfo, CLTV_FAR_FAR_AWAY}; +use ln::channelmanager::{HTLCForwardInfo, CLTV_FAR_FAR_AWAY, MIN_CLTV_EXPIRY_DELTA, PendingHTLCInfo, PendingHTLCRouting}; use ln::onion_utils; -use routing::network_graph::NetworkUpdate; -use routing::router::Route; -use ln::features::InitFeatures; +use routing::network_graph::{NetworkUpdate, RoutingFees}; +use routing::router::{get_route, PaymentParameters, Route, RouteHint, RouteHintHop}; +use ln::features::{InitFeatures, InvoiceFeatures}; use ln::msgs; use ln::msgs::{ChannelMessageHandler, ChannelUpdate, OptionalField}; use util::events::{Event, MessageSendEvent, MessageSendEventsProvider}; use util::ser::{Writeable, Writer}; +use util::test_utils; use util::config::UserConfig; use bitcoin::hash_types::BlockHash; use bitcoin::hashes::Hash; +use bitcoin::hashes::sha256::Hash as Sha256; use bitcoin::secp256k1; use bitcoin::secp256k1::Secp256k1; -use bitcoin::secp256k1::key::SecretKey; +use bitcoin::secp256k1::key::{PublicKey, SecretKey}; use io; use prelude::*; @@ -573,3 +576,104 @@ fn test_onion_failure() { nodes[2].node.fail_htlc_backwards(&payment_hash); }, true, Some(23), None, None); } + +macro_rules! get_phantom_route { + ($nodes: expr, $amt: expr, $channel: expr) => {{ + let secp_ctx = Secp256k1::new(); + let phantom_secret = $nodes[1].keys_manager.get_node_secret(Recipient::PhantomNode).unwrap(); + let phantom_pubkey = PublicKey::from_secret_key(&secp_ctx, &phantom_secret); + let phantom_route_hint = $nodes[1].node.get_phantom_route_hints(); + let payment_params = PaymentParameters::from_node_id(phantom_pubkey) + .with_features(InvoiceFeatures::known()) + .with_route_hints(vec![RouteHint(vec![ + RouteHintHop { + src_node_id: $nodes[0].node.get_our_node_id(), + short_channel_id: $channel.0.contents.short_channel_id, + fees: RoutingFees { + base_msat: $channel.0.contents.fee_base_msat, + proportional_millionths: $channel.0.contents.fee_proportional_millionths, + }, + cltv_expiry_delta: $channel.0.contents.cltv_expiry_delta, + htlc_minimum_msat: None, + htlc_maximum_msat: None, + }, + RouteHintHop { + src_node_id: phantom_route_hint.real_node_pubkey, + short_channel_id: phantom_route_hint.phantom_scid, + fees: RoutingFees { + base_msat: 0, + proportional_millionths: 0, + }, + cltv_expiry_delta: MIN_CLTV_EXPIRY_DELTA, + htlc_minimum_msat: None, + htlc_maximum_msat: None, + } + ])]); + let scorer = test_utils::TestScorer::with_penalty(0); + (get_route( + &$nodes[0].node.get_our_node_id(), &payment_params, $nodes[0].network_graph, + Some(&$nodes[0].node.list_usable_channels().iter().collect::>()), + $amt, TEST_FINAL_CLTV, $nodes[0].logger, &scorer + ).unwrap(), phantom_route_hint.phantom_scid) + } +}} + +#[test] +fn test_phantom_onion_hmac_failure() { + let chanmon_cfgs = create_chanmon_cfgs(2); + let node_cfgs = create_node_cfgs(2, &chanmon_cfgs); + let node_chanmgrs = create_node_chanmgrs(2, &node_cfgs, &[None, None]); + let nodes = create_network(2, &node_cfgs, &node_chanmgrs); + + let channel = create_announced_chan_between_nodes(&nodes, 0, 1, InitFeatures::known(), InitFeatures::known()); + + // Get the route. + let recv_value_msat = 10_000; + let (_, payment_hash, payment_secret) = get_payment_preimage_hash!(nodes[1], Some(recv_value_msat)); + let (route, phantom_scid) = get_phantom_route!(nodes, recv_value_msat, channel); + + // Route the HTLC through to the destination. + nodes[0].node.send_payment(&route, payment_hash.clone(), &Some(payment_secret)).unwrap(); + check_added_monitors!(nodes[0], 1); + let update_0 = get_htlc_update_msgs!(nodes[0], nodes[1].node.get_our_node_id()); + let mut update_add = update_0.update_add_htlcs[0].clone(); + + nodes[1].node.handle_update_add_htlc(&nodes[0].node.get_our_node_id(), &update_add); + commitment_signed_dance!(nodes[1], nodes[0], &update_0.commitment_signed, false, true); + + // Modify the payload so the phantom hop's HMAC is bogus. + let sha256_of_onion = { + let mut channel_state = nodes[1].node.channel_state.lock().unwrap(); + let mut pending_forward = channel_state.forward_htlcs.get_mut(&phantom_scid).unwrap(); + match pending_forward[0] { + HTLCForwardInfo::AddHTLC { + forward_info: PendingHTLCInfo { + routing: PendingHTLCRouting::Forward { ref mut onion_packet, .. }, + .. + }, .. + } => { + onion_packet.hmac[onion_packet.hmac.len() - 1] ^= 1; + Sha256::hash(&onion_packet.hop_data).into_inner().to_vec() + }, + _ => panic!("Unexpected forward"), + } + }; + expect_pending_htlcs_forwardable_ignore!(nodes[1]); + nodes[1].node.process_pending_htlc_forwards(); + expect_pending_htlcs_forwardable_ignore!(nodes[1]); + nodes[1].node.process_pending_htlc_forwards(); + let update_1 = get_htlc_update_msgs!(nodes[1], nodes[0].node.get_our_node_id()); + check_added_monitors!(&nodes[1], 1); + assert!(update_1.update_fail_htlcs.len() == 1); + let fail_msg = update_1.update_fail_htlcs[0].clone(); + nodes[0].node.handle_update_fail_htlc(&nodes[1].node.get_our_node_id(), &fail_msg); + commitment_signed_dance!(nodes[0], nodes[1], update_1.commitment_signed, false); + + // Ensure the payment fails with the expected error. + let mut fail_conditions = PaymentFailedConditions::new() + .blamed_scid(phantom_scid) + .blamed_chan_closed(true) + .expected_htlc_error_data(0x8000 | 0x4000 | 5, &sha256_of_onion); + expect_payment_failed_conditions!(nodes[0], payment_hash, false, fail_conditions); +} +