Merge pull request #2146 from valentinewallace/2023-03-blinded-pathfinding-groundwork

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

diff --git a/lightning/src/onion_message/utils.rs b/lightning/src/onion_message/utils.rs
deleted file mode 100644 (file)
index ae9e0a7..0000000
--- a/lightning/src/onion_message/utils.rs
+++ /dev/null
@@ -1,98 +0,0 @@
-// This file is Copyright its original authors, visible in version control
-// history.
-//
-// This file is licensed under the Apache License, Version 2.0 <LICENSE-APACHE
-// or http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
-// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your option.
-// You may not use this file except in accordance with one or both of these
-// licenses.
-
-//! Onion message utility methods live here.
-
-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, Scalar};
-use bitcoin::secp256k1::ecdh::SharedSecret;
-
-use crate::ln::onion_utils;
-use super::blinded_path::BlindedPath;
-use super::messenger::Destination;
-
-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>, 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();
-       let mut msg_blinding_point = PublicKey::from_secret_key(secp_ctx, &msg_blinding_point_priv);
-       let mut onion_packet_pubkey_priv = msg_blinding_point_priv.clone();
-       let mut onion_packet_pubkey = msg_blinding_point.clone();
-
-       macro_rules! build_keys {
-               ($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 {
-                               let hop_pk_blinding_factor = {
-                                       let mut hmac = HmacEngine::<Sha256>::new(b"blinded_node_id");
-                                       hmac.input(encrypted_data_ss.as_ref());
-                                       Hmac::from_engine(hmac).into_inner()
-                               };
-                               $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, $encrypted_payload);
-                       (encrypted_data_ss, onion_packet_ss)
-               }}
-       }
-
-       macro_rules! build_keys_in_loop {
-               ($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();
-                               sha.input(&msg_blinding_point.serialize()[..]);
-                               sha.input(encrypted_data_ss.as_ref());
-                               Sha256::from_engine(sha).into_inner()
-                       };
-
-                       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 = {
-                               let mut sha = Sha256::engine();
-                               sha.input(&onion_packet_pubkey.serialize()[..]);
-                               sha.input(onion_packet_ss.as_ref());
-                               Sha256::from_engine(sha).into_inner()
-                       };
-                       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_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(())
-}