Add a `payment_metadata` field to `RecipientOnionFields`

[rust-lightning] / lightning / src / onion_message / utils.rs

diff --git a/lightning/src/onion_message/utils.rs b/lightning/src/onion_message/utils.rs
index 785a373caa4c80d7783dc062208af9da28e087b3..ae9e0a7f6fee3e23b27c1aa9b1c63c51d1ea26cf 100644 (file)
--- a/lightning/src/onion_message/utils.rs
+++ b/lightning/src/onion_message/utils.rs
@@ -12,18 +12,20 @@
 use bitcoin::hashes::{Hash, HashEngine};
 use bitcoin::hashes::hmac::{Hmac, HmacEngine};
 use bitcoin::hashes::sha256::Hash as Sha256;
-use bitcoin::secp256k1::{self, PublicKey, Secp256k1, SecretKey};
+use bitcoin::secp256k1::{self, PublicKey, Secp256k1, SecretKey, Scalar};
 use bitcoin::secp256k1::ecdh::SharedSecret;
 
-use ln::onion_utils;
+use crate::ln::onion_utils;
+use super::blinded_path::BlindedPath;
+use super::messenger::Destination;
 
-use prelude::*;
+use crate::prelude::*;
 
 // TODO: DRY with onion_utils::construct_onion_keys_callback
 #[inline]
 pub(super) fn construct_keys_callback<T: secp256k1::Signing + secp256k1::Verification,
-       FType: FnMut(PublicKey, SharedSecret, PublicKey, [u8; 32], Option<PublicKey>)>(
-       secp_ctx: &Secp256k1<T>, unblinded_path: &[PublicKey],
+       FType: FnMut(PublicKey, SharedSecret, PublicKey, [u8; 32], Option<PublicKey>, Option<Vec<u8>>)>(
+       secp_ctx: &Secp256k1<T>, unblinded_path: &[PublicKey], destination: Option<Destination>,
        session_priv: &SecretKey, mut callback: FType
 ) -> Result<(), secp256k1::Error> {
        let mut msg_blinding_point_priv = session_priv.clone();
@@ -32,7 +34,7 @@ pub(super) fn construct_keys_callback<T: secp256k1::Signing + secp256k1::Verific
        let mut onion_packet_pubkey = msg_blinding_point.clone();
 
        macro_rules! build_keys {
-               ($pk: expr, $blinded: expr) => {
+               ($pk: expr, $blinded: expr, $encrypted_payload: expr) => {{
                        let encrypted_data_ss = SharedSecret::new(&$pk, &msg_blinding_point_priv);
 
                        let blinded_hop_pk = if $blinded { $pk } else {
@@ -41,15 +43,20 @@ pub(super) fn construct_keys_callback<T: secp256k1::Signing + secp256k1::Verific
                                        hmac.input(encrypted_data_ss.as_ref());
                                        Hmac::from_engine(hmac).into_inner()
                                };
-                               let mut unblinded_pk = $pk;
-                               unblinded_pk.mul_assign(secp_ctx, &hop_pk_blinding_factor)?;
-                               unblinded_pk
+                               $pk.mul_tweak(secp_ctx, &Scalar::from_be_bytes(hop_pk_blinding_factor).unwrap())?
                        };
                        let onion_packet_ss = SharedSecret::new(&blinded_hop_pk, &onion_packet_pubkey_priv);
 
                        let rho = onion_utils::gen_rho_from_shared_secret(encrypted_data_ss.as_ref());
                        let unblinded_pk_opt = if $blinded { None } else { Some($pk) };
-                       callback(blinded_hop_pk, onion_packet_ss, onion_packet_pubkey, rho, unblinded_pk_opt);
+                       callback(blinded_hop_pk, onion_packet_ss, onion_packet_pubkey, rho, unblinded_pk_opt, $encrypted_payload);
+                       (encrypted_data_ss, onion_packet_ss)
+               }}
+       }
+
+       macro_rules! build_keys_in_loop {
+               ($pk: expr, $blinded: expr, $encrypted_payload: expr) => {
+                       let (encrypted_data_ss, onion_packet_ss) = build_keys!($pk, $blinded, $encrypted_payload);
 
                        let msg_blinding_point_blinding_factor = {
                                let mut sha = Sha256::engine();
@@ -58,7 +65,7 @@ pub(super) fn construct_keys_callback<T: secp256k1::Signing + secp256k1::Verific
                                Sha256::from_engine(sha).into_inner()
                        };
 
-                       msg_blinding_point_priv.mul_assign(&msg_blinding_point_blinding_factor)?;
+                       msg_blinding_point_priv = msg_blinding_point_priv.mul_tweak(&Scalar::from_be_bytes(msg_blinding_point_blinding_factor).unwrap())?;
                        msg_blinding_point = PublicKey::from_secret_key(secp_ctx, &msg_blinding_point_priv);
 
                        let onion_packet_pubkey_blinding_factor = {
@@ -67,13 +74,25 @@ pub(super) fn construct_keys_callback<T: secp256k1::Signing + secp256k1::Verific
                                sha.input(onion_packet_ss.as_ref());
                                Sha256::from_engine(sha).into_inner()
                        };
-                       onion_packet_pubkey_priv.mul_assign(&onion_packet_pubkey_blinding_factor)?;
+                       onion_packet_pubkey_priv = onion_packet_pubkey_priv.mul_tweak(&Scalar::from_be_bytes(onion_packet_pubkey_blinding_factor).unwrap())?;
                        onion_packet_pubkey = PublicKey::from_secret_key(secp_ctx, &onion_packet_pubkey_priv);
                };
        }
 
        for pk in unblinded_path {
-               build_keys!(*pk, false);
+               build_keys_in_loop!(*pk, false, None);
+       }
+       if let Some(dest) = destination {
+               match dest {
+                       Destination::Node(pk) => {
+                               build_keys!(pk, false, None);
+                       },
+                       Destination::BlindedPath(BlindedPath { blinded_hops, .. }) => {
+                               for hop in blinded_hops {
+                                       build_keys_in_loop!(hop.blinded_node_id, true, Some(hop.encrypted_payload));
+                               }
+                       },
+               }
        }
        Ok(())
 }