use routing::router::RouteHop;
use util::chacha20::{ChaCha20, ChaChaReader};
use util::errors::{self, APIError};
-use util::ser::{Readable, Writeable, LengthCalculatingWriter};
+use util::ser::{Readable, ReadableArgs, Writeable, LengthCalculatingWriter};
use util::logger::Logger;
use bitcoin::hashes::{Hash, HashEngine};
Hmac::from_engine(hmac).into_inner()
}
-pub(
super) fn next_hop_packet_pubkey<T: secp256k1::Signing + secp256k1::Verification>(secp_ctx: &Secp256k1<T>, mut packet_pubkey: PublicKey, packet_shared_secret: &[u8; 32]) -> Result<PublicKey, secp256k1::Error> {
+pub(
crate) fn next_hop_packet_pubkey<T: secp256k1::Signing + secp256k1::Verification>(secp_ctx: &Secp256k1<T>, mut packet_pubkey: PublicKey, packet_shared_secret: &[u8; 32]) -> Result<PublicKey, secp256k1::Error> {
let blinding_factor = {
let mut sha = Sha256::engine();
sha.input(&packet_pubkey.serialize()[..]);
} else { unreachable!(); }
}
-/// Data decrypted from the onion payload.
+/// 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]> {
+ fn new(len: usize) -> Self;
+}
+
+impl NextPacketBytes for FixedSizeOnionPacket {
+ fn new(_len: usize) -> Self {
+ Self([0 as u8; ONION_DATA_LEN])
+ }
+}
+
+impl NextPacketBytes for Vec<u8> {
+ fn new(len: usize) -> Self {
+ vec![0 as u8; len]
+ }
+}
+
+/// Data decrypted from a payment's onion payload.
pub(crate) enum Hop {
/// This onion payload was for us, not for forwarding to a next-hop. Contains information for
/// verifying the incoming payment.
/// HMAC of the next hop's onion packet.
next_hop_hmac: [u8; 32],
/// Bytes of the onion packet we're forwarding.
- new_packet_bytes: [u8; 20*65],
+ new_packet_bytes: [u8; ONION_DATA_LEN],
},
}
/// Error returned when we fail to decode the onion packet.
+#[derive(Debug)]
pub(crate) enum OnionDecodeErr {
/// The HMAC of the onion packet did not match the hop data.
Malformed {
},
}
-pub(crate) fn decode_next_hop(shared_secret: [u8; 32], hop_data: &[u8], hmac_bytes: [u8; 32], payment_hash: PaymentHash) -> Result<Hop, 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) {
+ 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 {
+ next_hop_data,
+ next_hop_hmac,
+ new_packet_bytes
+ })
+ },
+ Err(e) => Err(e),
+ }
+}
+
+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> {
let (rho, mu) = gen_rho_mu_from_shared_secret(&shared_secret);
let mut hmac = HmacEngine::<Sha256>::new(&mu);
hmac.input(hop_data);
- hmac.input(&payment_hash.0[..]);
+ if let Some(payment_hash) = decode_input.payment_hash() {
+ hmac.input(&payment_hash.0[..]);
+ }
if !fixed_time_eq(&Hmac::from_engine(hmac).into_inner(), &hmac_bytes) {
return Err(OnionDecodeErr::Malformed {
err_msg: "HMAC Check failed",
let mut chacha = ChaCha20::new(&rho, &[0u8; 8]);
let mut chacha_stream = ChaChaReader { chacha: &mut chacha, read: Cursor::new(&hop_data[..]) };
- match <msgs::OnionHopData as Readable>::read(&mut chacha_stream) {
+ match R::read(&mut chacha_stream, decode_input.read_arg()) {
Err(err) => {
let error_code = match err {
msgs::DecodeError::UnknownVersion => 0x4000 | 1, // unknown realm byte
chacha_stream.read_exact(&mut next_bytes).unwrap();
assert_ne!(next_bytes[..], [0; 32][..]);
}
- return Ok(Hop::Receive(msg));
+ return Ok((msg, None)); // We are the final destination for this packet
} else {
- let mut new_packet_bytes = [0; 20*65];
- let read_pos = chacha_stream.read(&mut new_packet_bytes).unwrap();
+ let mut new_packet_bytes = N::new(hop_data.len());
+ let read_pos = hop_data.len() - chacha_stream.read.position() as usize;
+ chacha_stream.read_exact(&mut new_packet_bytes.as_mut()[..read_pos]).unwrap();
#[cfg(debug_assertions)]
{
// Check two things:
}
// Once we've emptied the set of bytes our peer gave us, encrypt 0 bytes until we
// fill the onion hop data we'll forward to our next-hop peer.
- chacha_stream.chacha.process_in_place(&mut new_packet_bytes[read_pos..]);
- return Ok(Hop::Forward {
- next_hop_data: msg,
- next_hop_hmac: hmac,
- new_packet_bytes,
- })
+ chacha_stream.chacha.process_in_place(&mut new_packet_bytes.as_mut()[read_pos..]);
+ return Ok((msg, Some((hmac, new_packet_bytes)))) // This packet needs forwarding
}
},
}
projects / rust-lightning / blobdiff