Allow(unused_imports) on prelude imports

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

diff --git a/lightning/src/blinded_path/utils.rs b/lightning/src/blinded_path/utils.rs
index 1993ad932267db8f2d2c8a98f999f2726530b833..7e43f31453637a6fdea2309d4713f2b34567693f 100644 (file)
--- a/lightning/src/blinded_path/utils.rs
+++ b/lightning/src/blinded_path/utils.rs
@@ -15,19 +15,29 @@ use bitcoin::hashes::sha256::Hash as Sha256;
 use bitcoin::secp256k1::{self, PublicKey, Secp256k1, SecretKey, Scalar};
 use bitcoin::secp256k1::ecdh::SharedSecret;
 
-use super::BlindedPath;
+use super::{BlindedHop, BlindedPath};
+use crate::ln::msgs::DecodeError;
 use crate::ln::onion_utils;
-use crate::onion_message::Destination;
+use crate::onion_message::messenger::Destination;
+use crate::crypto::streams::ChaChaPolyWriteAdapter;
+use crate::util::ser::{Readable, Writeable};
 
+use crate::io;
+
+#[allow(unused_imports)]
 use crate::prelude::*;
 
 // TODO: DRY with onion_utils::construct_onion_keys_callback
 #[inline]
-pub(crate) 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> {
+pub(crate) fn construct_keys_callback<'a, T, I, F>(
+       secp_ctx: &Secp256k1<T>, unblinded_path: I, destination: Option<Destination>,
+       session_priv: &SecretKey, mut callback: F
+) -> Result<(), secp256k1::Error>
+where
+       T: secp256k1::Signing + secp256k1::Verification,
+       I: Iterator<Item=&'a PublicKey>,
+       F: FnMut(PublicKey, SharedSecret, PublicKey, [u8; 32], Option<PublicKey>, Option<Vec<u8>>),
+{
        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();
@@ -41,7 +51,7 @@ pub(crate) fn construct_keys_callback<T: secp256k1::Signing + secp256k1::Verific
                                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()
+                                       Hmac::from_engine(hmac).to_byte_array()
                                };
                                $pk.mul_tweak(secp_ctx, &Scalar::from_be_bytes(hop_pk_blinding_factor).unwrap())?
                        };
@@ -62,7 +72,7 @@ pub(crate) fn construct_keys_callback<T: secp256k1::Signing + secp256k1::Verific
                                let mut sha = Sha256::engine();
                                sha.input(&msg_blinding_point.serialize()[..]);
                                sha.input(encrypted_data_ss.as_ref());
-                               Sha256::from_engine(sha).into_inner()
+                               Sha256::from_engine(sha).to_byte_array()
                        };
 
                        msg_blinding_point_priv = msg_blinding_point_priv.mul_tweak(&Scalar::from_be_bytes(msg_blinding_point_blinding_factor).unwrap())?;
@@ -72,7 +82,7 @@ pub(crate) fn construct_keys_callback<T: secp256k1::Signing + secp256k1::Verific
                                let mut sha = Sha256::engine();
                                sha.input(&onion_packet_pubkey.serialize()[..]);
                                sha.input(onion_packet_ss.as_ref());
-                               Sha256::from_engine(sha).into_inner()
+                               Sha256::from_engine(sha).to_byte_array()
                        };
                        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);
@@ -96,3 +106,46 @@ pub(crate) fn construct_keys_callback<T: secp256k1::Signing + secp256k1::Verific
        }
        Ok(())
 }
+
+// Panics if `unblinded_tlvs` length is less than `unblinded_pks` length
+pub(super) fn construct_blinded_hops<'a, T, I1, I2>(
+       secp_ctx: &Secp256k1<T>, unblinded_pks: I1, mut unblinded_tlvs: I2, session_priv: &SecretKey
+) -> Result<Vec<BlindedHop>, secp256k1::Error>
+where
+       T: secp256k1::Signing + secp256k1::Verification,
+       I1: Iterator<Item=&'a PublicKey>,
+       I2: Iterator,
+       I2::Item: Writeable
+{
+       let mut blinded_hops = Vec::with_capacity(unblinded_pks.size_hint().0);
+       construct_keys_callback(
+               secp_ctx, unblinded_pks, None, session_priv,
+               |blinded_node_id, _, _, encrypted_payload_rho, _, _| {
+                       blinded_hops.push(BlindedHop {
+                               blinded_node_id,
+                               encrypted_payload: encrypt_payload(unblinded_tlvs.next().unwrap(), encrypted_payload_rho),
+                       });
+               })?;
+       Ok(blinded_hops)
+}
+
+/// Encrypt TLV payload to be used as a [`crate::blinded_path::BlindedHop::encrypted_payload`].
+fn encrypt_payload<P: Writeable>(payload: P, encrypted_tlvs_rho: [u8; 32]) -> Vec<u8> {
+       let write_adapter = ChaChaPolyWriteAdapter::new(encrypted_tlvs_rho, &payload);
+       write_adapter.encode()
+}
+
+/// Blinded path encrypted payloads may be padded to ensure they are equal length.
+///
+/// Reads padding to the end, ignoring what's read.
+pub(crate) struct Padding {}
+impl Readable for Padding {
+       #[inline]
+       fn read<R: io::Read>(reader: &mut R) -> Result<Self, DecodeError> {
+               loop {
+                       let mut buf = [0; 8192];
+                       if reader.read(&mut buf[..])? == 0 { break; }
+               }
+               Ok(Self {})
+       }
+}