Merge pull request #3435 from jkczyz/2024-12-hmac-payment-context

Authenticate blinded payment paths

fuzz/src/chanmon_consistency.rs

@@ -50,6 +50,7 @@ use lightning::ln::channelmanager::{
 	ChainParameters, ChannelManager, ChannelManagerReadArgs, PaymentId, RecipientOnionFields, Retry,
 };
 use lightning::ln::functional_test_utils::*;
+use lightning::ln::inbound_payment::ExpandedKey;
 use lightning::ln::msgs::{
 	self, ChannelMessageHandler, CommitmentUpdate, DecodeError, Init, UpdateAddHTLC,
 };
@@ -60,9 +61,7 @@ use lightning::onion_message::messenger::{Destination, MessageRouter, OnionMessa
 use lightning::routing::router::{
 	InFlightHtlcs, Path, PaymentParameters, Route, RouteHop, RouteParameters, Router,
 };
-use lightning::sign::{
-	EntropySource, InMemorySigner, KeyMaterial, NodeSigner, Recipient, SignerProvider,
-};
+use lightning::sign::{EntropySource, InMemorySigner, NodeSigner, Recipient, SignerProvider};
 use lightning::types::payment::{PaymentHash, PaymentPreimage, PaymentSecret};
 use lightning::util::config::UserConfig;
 use lightning::util::errors::APIError;
@@ -334,10 +333,10 @@ impl NodeSigner for KeyProvider {
 		Ok(SharedSecret::new(other_key, &node_secret))
 	}
 
-	fn get_inbound_payment_key_material(&self) -> KeyMaterial {
+	fn get_inbound_payment_key(&self) -> ExpandedKey {
 		#[rustfmt::skip]
 		let random_bytes = [0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, self.node_secret[31]];
-		KeyMaterial(random_bytes)
+		ExpandedKey::new(random_bytes)
 	}
 
 	fn sign_invoice(

fuzz/src/full_stack.rs

@@ -43,6 +43,7 @@ use lightning::ln::channelmanager::{
 	ChainParameters, ChannelManager, InterceptId, PaymentId, RecipientOnionFields, Retry,
 };
 use lightning::ln::functional_test_utils::*;
+use lightning::ln::inbound_payment::ExpandedKey;
 use lightning::ln::msgs::{self, DecodeError};
 use lightning::ln::peer_handler::{
 	IgnoringMessageHandler, MessageHandler, PeerManager, SocketDescriptor,
@@ -56,9 +57,7 @@ use lightning::routing::router::{
 	InFlightHtlcs, PaymentParameters, Route, RouteParameters, Router,
 };
 use lightning::routing::utxo::UtxoLookup;
-use lightning::sign::{
-	EntropySource, InMemorySigner, KeyMaterial, NodeSigner, Recipient, SignerProvider,
-};
+use lightning::sign::{EntropySource, InMemorySigner, NodeSigner, Recipient, SignerProvider};
 use lightning::types::payment::{PaymentHash, PaymentPreimage, PaymentSecret};
 use lightning::util::config::{ChannelConfig, UserConfig};
 use lightning::util::errors::APIError;
@@ -79,7 +78,6 @@ use bitcoin::secp256k1::{self, Message, PublicKey, Scalar, Secp256k1, SecretKey}
 
 use std::cell::RefCell;
 use std::cmp;
-use std::convert::TryInto;
 use std::sync::atomic::{AtomicBool, AtomicU64, AtomicUsize, Ordering};
 use std::sync::{Arc, Mutex};
 
@@ -364,7 +362,7 @@ impl<'a> Drop for MoneyLossDetector<'a> {
 
 struct KeyProvider {
 	node_secret: SecretKey,
-	inbound_payment_key: KeyMaterial,
+	inbound_payment_key: ExpandedKey,
 	counter: AtomicU64,
 	signer_state: RefCell<HashMap<u8, (bool, Arc<Mutex<EnforcementState>>)>>,
 }
@@ -402,8 +400,8 @@ impl NodeSigner for KeyProvider {
 		Ok(SharedSecret::new(other_key, &node_secret))
 	}
 
-	fn get_inbound_payment_key_material(&self) -> KeyMaterial {
-		self.inbound_payment_key.clone()
+	fn get_inbound_payment_key(&self) -> ExpandedKey {
+		self.inbound_payment_key
 	}
 
 	fn sign_invoice(
@@ -636,7 +634,7 @@ pub fn do_test(mut data: &[u8], logger: &Arc<dyn Logger>) {
 
 	let keys_manager = Arc::new(KeyProvider {
 		node_secret: our_network_key.clone(),
-		inbound_payment_key: KeyMaterial(inbound_payment_key.try_into().unwrap()),
+		inbound_payment_key: ExpandedKey::new(inbound_payment_key),
 		counter: AtomicU64::new(0),
 		signer_state: RefCell::new(new_hash_map()),
 	});

fuzz/src/invoice_request_deser.rs

@@ -12,11 +12,13 @@ use bitcoin::secp256k1::{self, Keypair, Parity, PublicKey, Secp256k1, SecretKey}
 use core::convert::TryFrom;
 use lightning::blinded_path::payment::{
 	BlindedPaymentPath, Bolt12OfferContext, ForwardTlvs, PaymentConstraints, PaymentContext,
-	PaymentForwardNode, PaymentRelay, ReceiveTlvs,
+	PaymentForwardNode, PaymentRelay, UnauthenticatedReceiveTlvs,
 };
 use lightning::ln::channelmanager::MIN_FINAL_CLTV_EXPIRY_DELTA;
+use lightning::ln::inbound_payment::ExpandedKey;
 use lightning::offers::invoice::UnsignedBolt12Invoice;
 use lightning::offers::invoice_request::{InvoiceRequest, InvoiceRequestFields};
+use lightning::offers::nonce::Nonce;
 use lightning::offers::offer::OfferId;
 use lightning::offers::parse::Bolt12SemanticError;
 use lightning::sign::EntropySource;
@@ -80,7 +82,9 @@ fn privkey(byte: u8) -> SecretKey {
 fn build_response<T: secp256k1::Signing + secp256k1::Verification>(
 	invoice_request: &InvoiceRequest, secp_ctx: &Secp256k1<T>,
 ) -> Result<UnsignedBolt12Invoice, Bolt12SemanticError> {
+	let expanded_key = ExpandedKey::new([42; 32]);
 	let entropy_source = Randomness {};
+	let nonce = Nonce::from_entropy_source(&entropy_source);
 	let payment_context = PaymentContext::Bolt12Offer(Bolt12OfferContext {
 		offer_id: OfferId([42; 32]),
 		invoice_request: InvoiceRequestFields {
@@ -92,14 +96,15 @@ fn build_response<T: secp256k1::Signing + secp256k1::Verification>(
 			human_readable_name: None,
 		},
 	});
-	let payee_tlvs = ReceiveTlvs {
+	let payee_tlvs = UnauthenticatedReceiveTlvs {
 		payment_secret: PaymentSecret([42; 32]),
 		payment_constraints: PaymentConstraints {
 			max_cltv_expiry: 1_000_000,
 			htlc_minimum_msat: 1,
 		},
 		payment_context,
 	};
+	let payee_tlvs = payee_tlvs.authenticate(nonce, &expanded_key);
 	let intermediate_nodes = [PaymentForwardNode {
 		tlvs: ForwardTlvs {
 			short_channel_id: 43,
@@ -109,7 +114,7 @@ fn build_response<T: secp256k1::Signing + secp256k1::Verification>(
 				fee_base_msat: 1,
 			},
 			payment_constraints: PaymentConstraints {
-				max_cltv_expiry: payee_tlvs.payment_constraints.max_cltv_expiry + 40,
+				max_cltv_expiry: payee_tlvs.tlvs().payment_constraints.max_cltv_expiry + 40,
 				htlc_minimum_msat: 100,
 			},
 			features: BlindedHopFeatures::empty(),

fuzz/src/offer_deser.rs

@@ -16,7 +16,7 @@ use lightning::offers::invoice_request::InvoiceRequest;
 use lightning::offers::nonce::Nonce;
 use lightning::offers::offer::{Amount, Offer, Quantity};
 use lightning::offers::parse::Bolt12SemanticError;
-use lightning::sign::{EntropySource, KeyMaterial};
+use lightning::sign::EntropySource;
 use lightning::util::ser::Writeable;
 
 #[inline]
@@ -43,7 +43,7 @@ impl EntropySource for FixedEntropy {
 }
 
 fn build_request(offer: &Offer) -> Result<InvoiceRequest, Bolt12SemanticError> {
-	let expanded_key = ExpandedKey::new(&KeyMaterial([42; 32]));
+	let expanded_key = ExpandedKey::new([42; 32]);
 	let entropy = FixedEntropy {};
 	let nonce = Nonce::from_entropy_source(&entropy);
 	let secp_ctx = Secp256k1::new();

fuzz/src/onion_message.rs

@@ -9,6 +9,7 @@ use lightning::blinded_path::message::{
 	AsyncPaymentsContext, BlindedMessagePath, MessageContext, OffersContext,
 };
 use lightning::blinded_path::EmptyNodeIdLookUp;
+use lightning::ln::inbound_payment::ExpandedKey;
 use lightning::ln::msgs::{self, DecodeError, OnionMessageHandler};
 use lightning::ln::peer_handler::IgnoringMessageHandler;
 use lightning::ln::script::ShutdownScript;
@@ -22,7 +23,7 @@ use lightning::onion_message::messenger::{
 };
 use lightning::onion_message::offers::{OffersMessage, OffersMessageHandler};
 use lightning::onion_message::packet::OnionMessageContents;
-use lightning::sign::{EntropySource, KeyMaterial, NodeSigner, Recipient, SignerProvider};
+use lightning::sign::{EntropySource, NodeSigner, Recipient, SignerProvider};
 use lightning::types::features::InitFeatures;
 use lightning::util::logger::Logger;
 use lightning::util::ser::{Readable, Writeable, Writer};
@@ -223,7 +224,7 @@ impl NodeSigner for KeyProvider {
 		Ok(SharedSecret::new(other_key, &node_secret))
 	}
 
-	fn get_inbound_payment_key_material(&self) -> KeyMaterial {
+	fn get_inbound_payment_key(&self) -> ExpandedKey {
 		unreachable!()
 	}
 

fuzz/src/refund_deser.rs

@@ -12,10 +12,12 @@ use bitcoin::secp256k1::{self, Keypair, PublicKey, Secp256k1, SecretKey};
 use core::convert::TryFrom;
 use lightning::blinded_path::payment::{
 	BlindedPaymentPath, Bolt12RefundContext, ForwardTlvs, PaymentConstraints, PaymentContext,
-	PaymentForwardNode, PaymentRelay, ReceiveTlvs,
+	PaymentForwardNode, PaymentRelay, UnauthenticatedReceiveTlvs,
 };
 use lightning::ln::channelmanager::MIN_FINAL_CLTV_EXPIRY_DELTA;
+use lightning::ln::inbound_payment::ExpandedKey;
 use lightning::offers::invoice::UnsignedBolt12Invoice;
+use lightning::offers::nonce::Nonce;
 use lightning::offers::parse::Bolt12SemanticError;
 use lightning::offers::refund::Refund;
 use lightning::sign::EntropySource;
@@ -67,16 +69,19 @@ fn privkey(byte: u8) -> SecretKey {
 fn build_response<T: secp256k1::Signing + secp256k1::Verification>(
 	refund: &Refund, signing_pubkey: PublicKey, secp_ctx: &Secp256k1<T>,
 ) -> Result<UnsignedBolt12Invoice, Bolt12SemanticError> {
+	let expanded_key = ExpandedKey::new([42; 32]);
 	let entropy_source = Randomness {};
+	let nonce = Nonce::from_entropy_source(&entropy_source);
 	let payment_context = PaymentContext::Bolt12Refund(Bolt12RefundContext {});
-	let payee_tlvs = ReceiveTlvs {
+	let payee_tlvs = UnauthenticatedReceiveTlvs {
 		payment_secret: PaymentSecret([42; 32]),
 		payment_constraints: PaymentConstraints {
 			max_cltv_expiry: 1_000_000,
 			htlc_minimum_msat: 1,
 		},
 		payment_context,
 	};
+	let payee_tlvs = payee_tlvs.authenticate(nonce, &expanded_key);
 	let intermediate_nodes = [PaymentForwardNode {
 		tlvs: ForwardTlvs {
 			short_channel_id: 43,
@@ -86,7 +91,7 @@ fn build_response<T: secp256k1::Signing + secp256k1::Verification>(
 				fee_base_msat: 1,
 			},
 			payment_constraints: PaymentConstraints {
-				max_cltv_expiry: payee_tlvs.payment_constraints.max_cltv_expiry + 40,
+				max_cltv_expiry: payee_tlvs.tlvs().payment_constraints.max_cltv_expiry + 40,
 				htlc_minimum_msat: 100,
 			},
 			features: BlindedHopFeatures::empty(),

lightning-invoice/src/lib.rs

@@ -1086,6 +1086,7 @@ impl RawBolt11Invoice {
 
 	/// Calculate the hash of the encoded `RawBolt11Invoice` which should be signed.
 	pub fn signable_hash(&self) -> [u8; 32] {
+		#[cfg(not(fuzzing))]
 		use crate::ser::Base32Iterable;
 
 		Self::hash_from_parts(self.hrp.to_string().as_bytes(), self.data.fe_iter())