X-Git-Url: http://git.bitcoin.ninja/index.cgi?a=blobdiff_plain;f=lightning%2Fsrc%2Fln%2Fonion_utils.rs;h=953313955a50220ed9b7d9693897facc35fbf7e6;hb=6ca49948c169a297144d5d1474a2cef3827237e1;hp=598edcf0367952b011e290bfe48938ec92364ecb;hpb=f4f1093edc506314484c8d52a40dd155e692394b;p=rust-lightning

diff --git a/lightning/src/ln/onion_utils.rs b/lightning/src/ln/onion_utils.rs
index 598edcf0..95331395 100644
--- a/lightning/src/ln/onion_utils.rs
+++ b/lightning/src/ln/onion_utils.rs
@@ -589,31 +589,6 @@ pub(super) fn process_onion_failure<T: secp256k1::Signing, L: Deref>(secp_ctx: &
 	} else { unreachable!(); }
 }
 
-/// An input used when decoding an onion packet.
-pub(crate) trait DecodeInput {
-	type Arg;
-	/// If Some, this is the input when checking the hmac of the onion packet.
-	fn payment_hash(&self) -> Option<&PaymentHash>;
-	/// Read argument when decrypting our hop payload.
-	fn read_arg(self) -> Self::Arg;
-}
-
-impl DecodeInput for PaymentHash {
-	type Arg = ();
-	fn payment_hash(&self) -> Option<&PaymentHash> {
-		Some(self)
-	}
-	fn read_arg(self) -> Self::Arg { () }
-}
-
-impl DecodeInput for SharedSecret {
-	type Arg = SharedSecret;
-	fn payment_hash(&self) -> Option<&PaymentHash> {
-		None
-	}
-	fn read_arg(self) -> Self::Arg { self }
-}
-
 /// Allows `decode_next_hop` to return the next hop packet bytes for either payments or onion
 /// message forwards.
 pub(crate) trait NextPacketBytes: AsMut<[u8]> {
@@ -664,7 +639,7 @@ pub(crate) enum OnionDecodeErr {
 }
 
 pub(crate) fn decode_next_payment_hop(shared_secret: [u8; 32], hop_data: &[u8], hmac_bytes: [u8; 32], payment_hash: PaymentHash) -> Result<Hop, OnionDecodeErr> {
-	match decode_next_hop(shared_secret, hop_data, hmac_bytes, payment_hash) {
+	match decode_next_hop(shared_secret, hop_data, hmac_bytes, Some(payment_hash), ()) {
 		Ok((next_hop_data, None)) => Ok(Hop::Receive(next_hop_data)),
 		Ok((next_hop_data, Some((next_hop_hmac, FixedSizeOnionPacket(new_packet_bytes))))) => {
 			Ok(Hop::Forward {
@@ -677,12 +652,16 @@ pub(crate) fn decode_next_payment_hop(shared_secret: [u8; 32], hop_data: &[u8],
 	}
 }
 
-pub(crate) fn decode_next_hop<D: DecodeInput, R: ReadableArgs<D::Arg>, N: NextPacketBytes>(shared_secret: [u8; 32], hop_data: &[u8], hmac_bytes: [u8; 32], decode_input: D) -> Result<(R, Option<([u8; 32], N)>), OnionDecodeErr> {
+pub(crate) fn decode_next_untagged_hop<T, R: ReadableArgs<T>, N: NextPacketBytes>(shared_secret: [u8; 32], hop_data: &[u8], hmac_bytes: [u8; 32], read_args: T) -> Result<(R, Option<([u8; 32], N)>), OnionDecodeErr> {
+	decode_next_hop(shared_secret, hop_data, hmac_bytes, None, read_args)
+}
+
+fn decode_next_hop<T, R: ReadableArgs<T>, N: NextPacketBytes>(shared_secret: [u8; 32], hop_data: &[u8], hmac_bytes: [u8; 32], payment_hash: Option<PaymentHash>, read_args: T) -> Result<(R, Option<([u8; 32], N)>), OnionDecodeErr> {
 	let (rho, mu) = gen_rho_mu_from_shared_secret(&shared_secret);
 	let mut hmac = HmacEngine::<Sha256>::new(&mu);
 	hmac.input(hop_data);
-	if let Some(payment_hash) = decode_input.payment_hash() {
-		hmac.input(&payment_hash.0[..]);
+	if let Some(tag) = payment_hash {
+		hmac.input(&tag.0[..]);
 	}
 	if !fixed_time_eq(&Hmac::from_engine(hmac).into_inner(), &hmac_bytes) {
 		return Err(OnionDecodeErr::Malformed {
@@ -693,7 +672,7 @@ pub(crate) fn decode_next_hop<D: DecodeInput, R: ReadableArgs<D::Arg>, N: NextPa
 
 	let mut chacha = ChaCha20::new(&rho, &[0u8; 8]);
 	let mut chacha_stream = ChaChaReader { chacha: &mut chacha, read: Cursor::new(&hop_data[..]) };
-	match R::read(&mut chacha_stream, decode_input.read_arg()) {
+	match R::read(&mut chacha_stream, read_args) {
 		Err(err) => {
 			let error_code = match err {
 				msgs::DecodeError::UnknownVersion => 0x4000 | 1, // unknown realm byte