X-Git-Url: http://git.bitcoin.ninja/index.cgi?a=blobdiff_plain;f=lightning%2Fsrc%2Fln%2Fonion_utils.rs;h=ea906c9e32af86b2b1d21e3322eba082a4c195ea;hb=a1c92820b0800881e7f4289e3e77dae44f0a0cad;hp=31f2f7827bcb57c42d7b2a625a842abdaa00ab17;hpb=a0183d7ef1bdf95eb009b1c85849585e3faa0217;p=rust-lightning diff --git a/lightning/src/ln/onion_utils.rs b/lightning/src/ln/onion_utils.rs index 31f2f782..ea906c9e 100644 --- a/lightning/src/ln/onion_utils.rs +++ b/lightning/src/ln/onion_utils.rs @@ -242,6 +242,8 @@ pub(super) fn build_onion_payloads(path: &Path, total_msat: u64, mut recipient_o /// the hops can be of variable length. pub(crate) const ONION_DATA_LEN: usize = 20*65; +pub(super) const INVALID_ONION_BLINDING: u16 = 0x8000 | 0x4000 | 24; + #[inline] fn shift_slice_right(arr: &mut [u8], amt: usize) { for i in (amt..arr.len()).rev() { @@ -321,8 +323,6 @@ fn construct_onion_packet_with_init_noise( let mut pos = 0; for (i, (payload, keys)) in payloads.iter().zip(onion_keys.iter()).enumerate() { - if i == payloads.len() - 1 { break; } - let mut chacha = ChaCha20::new(&keys.rho, &[0u8; 8]); for _ in 0..(packet_data.len() - pos) { // TODO: Batch this. let mut dummy = [0; 1]; @@ -336,6 +336,8 @@ fn construct_onion_packet_with_init_noise( return Err(()); } + if i == payloads.len() - 1 { break; } + res.resize(pos, 0u8); chacha.process_in_place(&mut res); } @@ -433,11 +435,22 @@ pub(crate) struct DecodedOnionFailure { pub(crate) onion_error_data: Option>, } +/// Note that we always decrypt `packet` in-place here even if the deserialization into +/// [`msgs::DecodedOnionErrorPacket`] ultimately fails. +fn decrypt_onion_error_packet( + packet: &mut Vec, shared_secret: SharedSecret +) -> Result { + let ammag = gen_ammag_from_shared_secret(shared_secret.as_ref()); + let mut chacha = ChaCha20::new(&ammag, &[0u8; 8]); + chacha.process_in_place(packet); + msgs::DecodedOnionErrorPacket::read(&mut Cursor::new(packet)) +} + /// Process failure we got back from upstream on a payment we sent (implying htlc_source is an /// OutboundRoute). #[inline] pub(super) fn process_onion_failure( - secp_ctx: &Secp256k1, logger: &L, htlc_source: &HTLCSource, mut packet_decrypted: Vec + secp_ctx: &Secp256k1, logger: &L, htlc_source: &HTLCSource, mut encrypted_packet: Vec ) -> DecodedOnionFailure where L::Target: Logger { let (path, session_priv, first_hop_htlc_msat) = if let &HTLCSource::OutboundRoute { ref path, ref session_priv, ref first_hop_htlc_msat, .. @@ -491,8 +504,21 @@ pub(super) fn process_onion_failure( Some(hop) => hop, None => { // The failing hop is within a multi-hop blinded path. - error_code_ret = Some(BADONION | PERM | 24); // invalid_onion_blinding - error_packet_ret = Some(vec![0; 32]); + #[cfg(not(test))] { + error_code_ret = Some(BADONION | PERM | 24); // invalid_onion_blinding + error_packet_ret = Some(vec![0; 32]); + } + #[cfg(test)] { + // Actually parse the onion error data in tests so we can check that blinded hops fail + // back correctly. + let err_packet = decrypt_onion_error_packet( + &mut encrypted_packet, shared_secret + ).unwrap(); + error_code_ret = + Some(u16::from_be_bytes(err_packet.failuremsg.get(0..2).unwrap().try_into().unwrap())); + error_packet_ret = Some(err_packet.failuremsg[2..].to_vec()); + } + res = Some(FailureLearnings { network_update: None, short_channel_id: None, payment_failed_permanently: false }); @@ -504,15 +530,7 @@ pub(super) fn process_onion_failure( let amt_to_forward = htlc_msat - route_hop.fee_msat; htlc_msat = amt_to_forward; - let ammag = gen_ammag_from_shared_secret(shared_secret.as_ref()); - - let mut decryption_tmp = Vec::with_capacity(packet_decrypted.len()); - decryption_tmp.resize(packet_decrypted.len(), 0); - let mut chacha = ChaCha20::new(&ammag, &[0u8; 8]); - chacha.process(&packet_decrypted, &mut decryption_tmp[..]); - packet_decrypted = decryption_tmp; - - let err_packet = match msgs::DecodedOnionErrorPacket::read(&mut Cursor::new(&packet_decrypted)) { + let err_packet = match decrypt_onion_error_packet(&mut encrypted_packet, shared_secret) { Ok(p) => p, Err(_) => return }; @@ -722,9 +740,11 @@ pub(super) fn process_onion_failure( } #[derive(Clone)] // See Channel::revoke_and_ack for why, tl;dr: Rust bug +#[cfg_attr(test, derive(PartialEq))] pub(super) struct HTLCFailReason(HTLCFailReasonRepr); #[derive(Clone)] // See Channel::revoke_and_ack for why, tl;dr: Rust bug +#[cfg_attr(test, derive(PartialEq))] enum HTLCFailReasonRepr { LightningError { err: msgs::OnionErrorPacket, @@ -1001,18 +1021,20 @@ fn decode_next_hop, N: NextPacketBytes>(shared_secret: [u8 if hmac == [0; 32] { #[cfg(test)] { - // In tests, make sure that the initial onion packet data is, at least, non-0. - // We could do some fancy randomness test here, but, ehh, whatever. - // This checks for the issue where you can calculate the path length given the - // onion data as all the path entries that the originator sent will be here - // as-is (and were originally 0s). - // Of course reverse path calculation is still pretty easy given naive routing - // algorithms, but this fixes the most-obvious case. - let mut next_bytes = [0; 32]; - chacha_stream.read_exact(&mut next_bytes).unwrap(); - assert_ne!(next_bytes[..], [0; 32][..]); - chacha_stream.read_exact(&mut next_bytes).unwrap(); - assert_ne!(next_bytes[..], [0; 32][..]); + if chacha_stream.read.position() < hop_data.len() as u64 - 64 { + // In tests, make sure that the initial onion packet data is, at least, non-0. + // We could do some fancy randomness test here, but, ehh, whatever. + // This checks for the issue where you can calculate the path length given the + // onion data as all the path entries that the originator sent will be here + // as-is (and were originally 0s). + // Of course reverse path calculation is still pretty easy given naive routing + // algorithms, but this fixes the most-obvious case. + let mut next_bytes = [0; 32]; + chacha_stream.read_exact(&mut next_bytes).unwrap(); + assert_ne!(next_bytes[..], [0; 32][..]); + chacha_stream.read_exact(&mut next_bytes).unwrap(); + assert_ne!(next_bytes[..], [0; 32][..]); + } } return Ok((msg, None)); // We are the final destination for this packet } else {