_ Git - rust-lightning/blob - lightning/src/ln/onion_utils.rs

   1 // This file is Copyright its original authors, visible in version control
   2 // history.
   3 //
   4 // This file is licensed under the Apache License, Version 2.0 <LICENSE-APACHE
   5 // or http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
   6 // <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your option.
   7 // You may not use this file except in accordance with one or both of these
   8 // licenses.
   9
  10 use crate::ln::{PaymentHash, PaymentPreimage};
  11 use crate::ln::channelmanager::{HTLCSource, RecipientOnionFields};
  12 use crate::ln::msgs;
  13 use crate::ln::wire::Encode;
  14 use crate::routing::gossip::NetworkUpdate;
  15 use crate::routing::router::{BlindedTail, Path, RouteHop};
  16 use crate::sign::NodeSigner;
  17 use crate::util::chacha20::{ChaCha20, ChaChaReader};
  18 use crate::util::errors::{self, APIError};
  19 use crate::util::ser::{Readable, ReadableArgs, Writeable, Writer, LengthCalculatingWriter};
  20 use crate::util::logger::Logger;
  21
  22 use bitcoin::hashes::{Hash, HashEngine};
  23 use bitcoin::hashes::cmp::fixed_time_eq;
  24 use bitcoin::hashes::hmac::{Hmac, HmacEngine};
  25 use bitcoin::hashes::sha256::Hash as Sha256;
  26
  27 use bitcoin::secp256k1::{SecretKey, PublicKey, Scalar};
  28 use bitcoin::secp256k1::Secp256k1;
  29 use bitcoin::secp256k1::ecdh::SharedSecret;
  30 use bitcoin::secp256k1;
  31
  32 use crate::prelude::*;
  33 use crate::io::{Cursor, Read};
  34 use core::convert::{AsMut, TryInto};
  35 use core::ops::Deref;
  36
  37 pub(crate) struct OnionKeys {
  38         #[cfg(test)]
  39         pub(crate) shared_secret: SharedSecret,
  40         #[cfg(test)]
  41         pub(crate) blinding_factor: [u8; 32],
  42         pub(crate) ephemeral_pubkey: PublicKey,
  43         pub(crate) rho: [u8; 32],
  44         pub(crate) mu: [u8; 32],
  45 }
  46
  47 #[inline]
  48 pub(crate) fn gen_rho_from_shared_secret(shared_secret: &[u8]) -> [u8; 32] {
  49         assert_eq!(shared_secret.len(), 32);
  50         let mut hmac = HmacEngine::<Sha256>::new(&[0x72, 0x68, 0x6f]); // rho
  51         hmac.input(&shared_secret);
  52         Hmac::from_engine(hmac).to_byte_array()
  53 }
  54
  55 #[inline]
  56 pub(crate) fn gen_rho_mu_from_shared_secret(shared_secret: &[u8]) -> ([u8; 32], [u8; 32]) {
  57         assert_eq!(shared_secret.len(), 32);
  58         ({
  59                 let mut hmac = HmacEngine::<Sha256>::new(&[0x72, 0x68, 0x6f]); // rho
  60                 hmac.input(&shared_secret);
  61                 Hmac::from_engine(hmac).to_byte_array()
  62         },
  63         {
  64                 let mut hmac = HmacEngine::<Sha256>::new(&[0x6d, 0x75]); // mu
  65                 hmac.input(&shared_secret);
  66                 Hmac::from_engine(hmac).to_byte_array()
  67         })
  68 }
  69
  70 #[inline]
  71 pub(super) fn gen_um_from_shared_secret(shared_secret: &[u8]) -> [u8; 32] {
  72         assert_eq!(shared_secret.len(), 32);
  73         let mut hmac = HmacEngine::<Sha256>::new(&[0x75, 0x6d]); // um
  74         hmac.input(&shared_secret);
  75         Hmac::from_engine(hmac).to_byte_array()
  76 }
  77
  78 #[inline]
  79 pub(super) fn gen_ammag_from_shared_secret(shared_secret: &[u8]) -> [u8; 32] {
  80         assert_eq!(shared_secret.len(), 32);
  81         let mut hmac = HmacEngine::<Sha256>::new(&[0x61, 0x6d, 0x6d, 0x61, 0x67]); // ammag
  82         hmac.input(&shared_secret);
  83         Hmac::from_engine(hmac).to_byte_array()
  84 }
  85
  86 #[cfg(test)]
  87 #[inline]
  88 pub(super) fn gen_pad_from_shared_secret(shared_secret: &[u8]) -> [u8; 32] {
  89         assert_eq!(shared_secret.len(), 32);
  90         let mut hmac = HmacEngine::<Sha256>::new(&[0x70, 0x61, 0x64]); // pad
  91         hmac.input(&shared_secret);
  92         Hmac::from_engine(hmac).to_byte_array()
  93 }
  94
  95 /// Calculates a pubkey for the next hop, such as the next hop's packet pubkey or blinding point.
  96 pub(crate) fn next_hop_pubkey<T: secp256k1::Verification>(
  97         secp_ctx: &Secp256k1<T>, curr_pubkey: PublicKey, shared_secret: &[u8]
  98 ) -> Result<PublicKey, secp256k1::Error> {
  99         let blinding_factor = {
 100                 let mut sha = Sha256::engine();
 101                 sha.input(&curr_pubkey.serialize()[..]);
 102                 sha.input(shared_secret);
 103                 Sha256::from_engine(sha).to_byte_array()
 104         };
 105
 106         curr_pubkey.mul_tweak(secp_ctx, &Scalar::from_be_bytes(blinding_factor).unwrap())
 107 }
 108
 109 // can only fail if an intermediary hop has an invalid public key or session_priv is invalid
 110 #[inline]
 111 pub(super) fn construct_onion_keys_callback<T, FType>(
 112         secp_ctx: &Secp256k1<T>, path: &Path, session_priv: &SecretKey, mut callback: FType
 113 ) -> Result<(), secp256k1::Error>
 114 where
 115         T: secp256k1::Signing,
 116         FType: FnMut(SharedSecret, [u8; 32], PublicKey, Option<&RouteHop>, usize)
 117 {
 118         let mut blinded_priv = session_priv.clone();
 119         let mut blinded_pub = PublicKey::from_secret_key(secp_ctx, &blinded_priv);
 120
 121         let unblinded_hops_iter = path.hops.iter().map(|h| (&h.pubkey, Some(h)));
 122         let blinded_pks_iter = path.blinded_tail.as_ref()
 123                 .map(|t| t.hops.iter()).unwrap_or([].iter())
 124                 .skip(1) // Skip the intro node because it's included in the unblinded hops
 125                 .map(|h| (&h.blinded_node_id, None));
 126         for (idx, (pubkey, route_hop_opt)) in unblinded_hops_iter.chain(blinded_pks_iter).enumerate() {
 127                 let shared_secret = SharedSecret::new(pubkey, &blinded_priv);
 128
 129                 let mut sha = Sha256::engine();
 130                 sha.input(&blinded_pub.serialize()[..]);
 131                 sha.input(shared_secret.as_ref());
 132                 let blinding_factor = Sha256::from_engine(sha).to_byte_array();
 133
 134                 let ephemeral_pubkey = blinded_pub;
 135
 136                 blinded_priv = blinded_priv.mul_tweak(&Scalar::from_be_bytes(blinding_factor).unwrap())?;
 137                 blinded_pub = PublicKey::from_secret_key(secp_ctx, &blinded_priv);
 138
 139                 callback(shared_secret, blinding_factor, ephemeral_pubkey, route_hop_opt, idx);
 140         }
 141
 142         Ok(())
 143 }
 144
 145 // can only fail if an intermediary hop has an invalid public key or session_priv is invalid
 146 pub(super) fn construct_onion_keys<T: secp256k1::Signing>(secp_ctx: &Secp256k1<T>, path: &Path, session_priv: &SecretKey) -> Result<Vec<OnionKeys>, secp256k1::Error> {
 147         let mut res = Vec::with_capacity(path.hops.len());
 148
 149         construct_onion_keys_callback(secp_ctx, &path, session_priv,
 150                 |shared_secret, _blinding_factor, ephemeral_pubkey, _, _|
 151         {
 152                 let (rho, mu) = gen_rho_mu_from_shared_secret(shared_secret.as_ref());
 153
 154                 res.push(OnionKeys {
 155                         #[cfg(test)]
 156                         shared_secret,
 157                         #[cfg(test)]
 158                         blinding_factor: _blinding_factor,
 159                         ephemeral_pubkey,
 160                         rho,
 161                         mu,
 162                 });
 163         })?;
 164
 165         Ok(res)
 166 }
 167
 168 /// returns the hop data, as well as the first-hop value_msat and CLTV value we should send.
 169 pub(super) fn build_onion_payloads(path: &Path, total_msat: u64, mut recipient_onion: RecipientOnionFields, starting_htlc_offset: u32, keysend_preimage: &Option<PaymentPreimage>) -> Result<(Vec<msgs::OutboundOnionPayload>, u64, u32), APIError> {
 170         let mut cur_value_msat = 0u64;
 171         let mut cur_cltv = starting_htlc_offset;
 172         let mut last_short_channel_id = 0;
 173         let mut res: Vec<msgs::OutboundOnionPayload> = Vec::with_capacity(
 174                 path.hops.len() + path.blinded_tail.as_ref().map_or(0, |t| t.hops.len())
 175         );
 176
 177         for (idx, hop) in path.hops.iter().rev().enumerate() {
 178                 // First hop gets special values so that it can check, on receipt, that everything is
 179                 // exactly as it should be (and the next hop isn't trying to probe to find out if we're
 180                 // the intended recipient).
 181                 let value_msat = if cur_value_msat == 0 { hop.fee_msat } else { cur_value_msat };
 182                 let cltv = if cur_cltv == starting_htlc_offset { hop.cltv_expiry_delta + starting_htlc_offset } else { cur_cltv };
 183                 if idx == 0 {
 184                         if let Some(BlindedTail {
 185                                 blinding_point, hops, final_value_msat, excess_final_cltv_expiry_delta, ..
 186                         }) = &path.blinded_tail {
 187                                 let mut blinding_point = Some(*blinding_point);
 188                                 for (i, blinded_hop) in hops.iter().enumerate() {
 189                                         if i == hops.len() - 1 {
 190                                                 cur_value_msat += final_value_msat;
 191                                                 cur_cltv += excess_final_cltv_expiry_delta;
 192                                                 res.push(msgs::OutboundOnionPayload::BlindedReceive {
 193                                                         amt_msat: *final_value_msat,
 194                                                         total_msat,
 195                                                         outgoing_cltv_value: cltv,
 196                                                         encrypted_tlvs: blinded_hop.encrypted_payload.clone(),
 197                                                         intro_node_blinding_point: blinding_point.take(),
 198                                                 });
 199                                         } else {
 200                                                 res.push(msgs::OutboundOnionPayload::BlindedForward {
 201                                                         encrypted_tlvs: blinded_hop.encrypted_payload.clone(),
 202                                                         intro_node_blinding_point: blinding_point.take(),
 203                                                 });
 204                                         }
 205                                 }
 206                         } else {
 207                                 res.push(msgs::OutboundOnionPayload::Receive {
 208                                         payment_data: if let Some(secret) = recipient_onion.payment_secret.take() {
 209                                                 Some(msgs::FinalOnionHopData {
 210                                                         payment_secret: secret,
 211                                                         total_msat,
 212                                                 })
 213                                         } else { None },
 214                                         payment_metadata: recipient_onion.payment_metadata.take(),
 215                                         keysend_preimage: *keysend_preimage,
 216                                         custom_tlvs: recipient_onion.custom_tlvs.clone(),
 217                                         amt_msat: value_msat,
 218                                         outgoing_cltv_value: cltv,
 219                                 });
 220                         }
 221                 } else {
 222                         res.insert(0, msgs::OutboundOnionPayload::Forward {
 223                                 short_channel_id: last_short_channel_id,
 224                                 amt_to_forward: value_msat,
 225                                 outgoing_cltv_value: cltv,
 226                         });
 227                 }
 228                 cur_value_msat += hop.fee_msat;
 229                 if cur_value_msat >= 21000000 * 100000000 * 1000 {
 230                         return Err(APIError::InvalidRoute{err: "Channel fees overflowed?".to_owned()});
 231                 }
 232                 cur_cltv += hop.cltv_expiry_delta as u32;
 233                 if cur_cltv >= 500000000 {
 234                         return Err(APIError::InvalidRoute{err: "Channel CLTV overflowed?".to_owned()});
 235                 }
 236                 last_short_channel_id = hop.short_channel_id;
 237         }
 238         Ok((res, cur_value_msat, cur_cltv))
 239 }
 240
 241 /// Length of the onion data packet. Before TLV-based onions this was 20 65-byte hops, though now
 242 /// the hops can be of variable length.
 243 pub(crate) const ONION_DATA_LEN: usize = 20*65;
 244
 245 pub(super) const INVALID_ONION_BLINDING: u16 = 0x8000 | 0x4000 | 24;
 246
 247 #[inline]
 248 fn shift_slice_right(arr: &mut [u8], amt: usize) {
 249         for i in (amt..arr.len()).rev() {
 250                 arr[i] = arr[i-amt];
 251         }
 252         for i in 0..amt {
 253                 arr[i] = 0;
 254         }
 255 }
 256
 257 pub(super) fn construct_onion_packet(
 258         payloads: Vec<msgs::OutboundOnionPayload>, onion_keys: Vec<OnionKeys>, prng_seed: [u8; 32],
 259         associated_data: &PaymentHash
 260 ) -> Result<msgs::OnionPacket, ()> {
 261         let mut packet_data = [0; ONION_DATA_LEN];
 262
 263         let mut chacha = ChaCha20::new(&prng_seed, &[0; 8]);
 264         chacha.process(&[0; ONION_DATA_LEN], &mut packet_data);
 265
 266         construct_onion_packet_with_init_noise::<_, _>(
 267                 payloads, onion_keys, FixedSizeOnionPacket(packet_data), Some(associated_data))
 268 }
 269
 270 #[cfg(test)]
 271 /// Used in testing to write bogus `BogusOnionHopData` as well as `RawOnionHopData`, which is
 272 /// otherwise not representable in `msgs::OnionHopData`.
 273 pub(super) fn construct_onion_packet_with_writable_hopdata<HD: Writeable>(payloads: Vec<HD>, onion_keys: Vec<OnionKeys>, prng_seed: [u8; 32], associated_data: &PaymentHash) -> Result<msgs::OnionPacket, ()> {
 274         let mut packet_data = [0; ONION_DATA_LEN];
 275
 276         let mut chacha = ChaCha20::new(&prng_seed, &[0; 8]);
 277         chacha.process(&[0; ONION_DATA_LEN], &mut packet_data);
 278
 279         construct_onion_packet_with_init_noise::<_, _>(
 280                 payloads, onion_keys, FixedSizeOnionPacket(packet_data), Some(associated_data))
 281 }
 282
 283 /// Since onion message packets and onion payment packets have different lengths but are otherwise
 284 /// identical, we use this trait to allow `construct_onion_packet_with_init_noise` to return either
 285 /// type.
 286 pub(crate) trait Packet {
 287         type Data: AsMut<[u8]>;
 288         fn new(pubkey: PublicKey, hop_data: Self::Data, hmac: [u8; 32]) -> Self;
 289 }
 290
 291 // Needed for rustc versions older than 1.47 to avoid E0277: "arrays only have std trait
 292 // implementations for lengths 0..=32".
 293 pub(crate) struct FixedSizeOnionPacket(pub(crate) [u8; ONION_DATA_LEN]);
 294
 295 impl AsMut<[u8]> for FixedSizeOnionPacket {
 296         fn as_mut(&mut self) -> &mut [u8] {
 297                 &mut self.0
 298         }
 299 }
 300
 301 pub(crate) fn payloads_serialized_length<HD: Writeable>(payloads: &Vec<HD>) -> usize {
 302         payloads.iter().map(|p| p.serialized_length() + 32 /* HMAC */).sum()
 303 }
 304
 305 pub(crate) fn construct_onion_message_packet<HD: Writeable, P: Packet<Data = Vec<u8>>>(
 306         payloads: Vec<HD>, onion_keys: Vec<OnionKeys>, prng_seed: [u8; 32], packet_data_len: usize) -> Result<P, ()>
 307 {
 308         let mut packet_data = vec![0; packet_data_len];
 309
 310         let mut chacha = ChaCha20::new(&prng_seed, &[0; 8]);
 311         chacha.process_in_place(&mut packet_data);
 312
 313         construct_onion_packet_with_init_noise::<_, _>(payloads, onion_keys, packet_data, None)
 314 }
 315
 316 fn construct_onion_packet_with_init_noise<HD: Writeable, P: Packet>(
 317         mut payloads: Vec<HD>, onion_keys: Vec<OnionKeys>, mut packet_data: P::Data, associated_data: Option<&PaymentHash>) -> Result<P, ()>
 318 {
 319         let filler = {
 320                 let packet_data = packet_data.as_mut();
 321                 const ONION_HOP_DATA_LEN: usize = 65; // We may decrease this eventually after TLV is common
 322                 let mut res = Vec::with_capacity(ONION_HOP_DATA_LEN * (payloads.len() - 1));
 323
 324                 let mut pos = 0;
 325                 for (i, (payload, keys)) in payloads.iter().zip(onion_keys.iter()).enumerate() {
 326                         let mut chacha = ChaCha20::new(&keys.rho, &[0u8; 8]);
 327                         for _ in 0..(packet_data.len() - pos) { // TODO: Batch this.
 328                                 let mut dummy = [0; 1];
 329                                 chacha.process_in_place(&mut dummy); // We don't have a seek function :(
 330                         }
 331
 332                         let mut payload_len = LengthCalculatingWriter(0);
 333                         payload.write(&mut payload_len).expect("Failed to calculate length");
 334                         pos += payload_len.0 + 32;
 335                         if pos > packet_data.len() {
 336                                 return Err(());
 337                         }
 338
 339                         if i == payloads.len() - 1 { break; }
 340
 341                         res.resize(pos, 0u8);
 342                         chacha.process_in_place(&mut res);
 343                 }
 344                 res
 345         };
 346
 347         let mut hmac_res = [0; 32];
 348         for (i, (payload, keys)) in payloads.iter_mut().zip(onion_keys.iter()).rev().enumerate() {
 349                 let mut payload_len = LengthCalculatingWriter(0);
 350                 payload.write(&mut payload_len).expect("Failed to calculate length");
 351
 352                 let packet_data = packet_data.as_mut();
 353                 shift_slice_right(packet_data, payload_len.0 + 32);
 354                 packet_data[0..payload_len.0].copy_from_slice(&payload.encode()[..]);
 355                 packet_data[payload_len.0..(payload_len.0 + 32)].copy_from_slice(&hmac_res);
 356
 357                 let mut chacha = ChaCha20::new(&keys.rho, &[0u8; 8]);
 358                 chacha.process_in_place(packet_data);
 359
 360                 if i == 0 {
 361                         let stop_index = packet_data.len();
 362                         let start_index = stop_index.checked_sub(filler.len()).ok_or(())?;
 363                         packet_data[start_index..stop_index].copy_from_slice(&filler[..]);
 364                 }
 365
 366                 let mut hmac = HmacEngine::<Sha256>::new(&keys.mu);
 367                 hmac.input(packet_data);
 368                 if let Some(associated_data) = associated_data {
 369                         hmac.input(&associated_data.0[..]);
 370                 }
 371                 hmac_res = Hmac::from_engine(hmac).to_byte_array();
 372         }
 373
 374         Ok(P::new(onion_keys.first().unwrap().ephemeral_pubkey, packet_data, hmac_res))
 375 }
 376
 377 /// Encrypts a failure packet. raw_packet can either be a
 378 /// msgs::DecodedOnionErrorPacket.encode() result or a msgs::OnionErrorPacket.data element.
 379 pub(super) fn encrypt_failure_packet(shared_secret: &[u8], raw_packet: &[u8]) -> msgs::OnionErrorPacket {
 380         let ammag = gen_ammag_from_shared_secret(&shared_secret);
 381
 382         let mut packet_crypted = Vec::with_capacity(raw_packet.len());
 383         packet_crypted.resize(raw_packet.len(), 0);
 384         let mut chacha = ChaCha20::new(&ammag, &[0u8; 8]);
 385         chacha.process(&raw_packet, &mut packet_crypted[..]);
 386         msgs::OnionErrorPacket {
 387                 data: packet_crypted,
 388         }
 389 }
 390
 391 pub(super) fn build_failure_packet(shared_secret: &[u8], failure_type: u16, failure_data: &[u8]) -> msgs::DecodedOnionErrorPacket {
 392         assert_eq!(shared_secret.len(), 32);
 393         assert!(failure_data.len() <= 256 - 2);
 394
 395         let um = gen_um_from_shared_secret(&shared_secret);
 396
 397         let failuremsg = {
 398                 let mut res = Vec::with_capacity(2 + failure_data.len());
 399                 res.push(((failure_type >> 8) & 0xff) as u8);
 400                 res.push(((failure_type >> 0) & 0xff) as u8);
 401                 res.extend_from_slice(&failure_data[..]);
 402                 res
 403         };
 404         let pad = {
 405                 let mut res = Vec::with_capacity(256 - 2 - failure_data.len());
 406                 res.resize(256 - 2 - failure_data.len(), 0);
 407                 res
 408         };
 409         let mut packet = msgs::DecodedOnionErrorPacket {
 410                 hmac: [0; 32],
 411                 failuremsg,
 412                 pad,
 413         };
 414
 415         let mut hmac = HmacEngine::<Sha256>::new(&um);
 416         hmac.input(&packet.encode()[32..]);
 417         packet.hmac = Hmac::from_engine(hmac).to_byte_array();
 418
 419         packet
 420 }
 421
 422 #[cfg(test)]
 423 pub(super) fn build_first_hop_failure_packet(shared_secret: &[u8], failure_type: u16, failure_data: &[u8]) -> msgs::OnionErrorPacket {
 424         let failure_packet = build_failure_packet(shared_secret, failure_type, failure_data);
 425         encrypt_failure_packet(shared_secret, &failure_packet.encode()[..])
 426 }
 427
 428 pub(crate) struct DecodedOnionFailure {
 429         pub(crate) network_update: Option<NetworkUpdate>,
 430         pub(crate) short_channel_id: Option<u64>,
 431         pub(crate) payment_failed_permanently: bool,
 432         #[cfg(test)]
 433         pub(crate) onion_error_code: Option<u16>,
 434         #[cfg(test)]
 435         pub(crate) onion_error_data: Option<Vec<u8>>,
 436 }
 437
 438 /// Note that we always decrypt `packet` in-place here even if the deserialization into
 439 /// [`msgs::DecodedOnionErrorPacket`] ultimately fails.
 440 fn decrypt_onion_error_packet(
 441         packet: &mut Vec<u8>, shared_secret: SharedSecret
 442 ) -> Result<msgs::DecodedOnionErrorPacket, msgs::DecodeError> {
 443         let ammag = gen_ammag_from_shared_secret(shared_secret.as_ref());
 444         let mut chacha = ChaCha20::new(&ammag, &[0u8; 8]);
 445         chacha.process_in_place(packet);
 446         msgs::DecodedOnionErrorPacket::read(&mut Cursor::new(packet))
 447 }
 448
 449 /// Process failure we got back from upstream on a payment we sent (implying htlc_source is an
 450 /// OutboundRoute).
 451 #[inline]
 452 pub(super) fn process_onion_failure<T: secp256k1::Signing, L: Deref>(
 453         secp_ctx: &Secp256k1<T>, logger: &L, htlc_source: &HTLCSource, mut encrypted_packet: Vec<u8>
 454 ) -> DecodedOnionFailure where L::Target: Logger {
 455         let (path, session_priv, first_hop_htlc_msat) = if let &HTLCSource::OutboundRoute {
 456                 ref path, ref session_priv, ref first_hop_htlc_msat, ..
 457         } = htlc_source {
 458                 (path, session_priv, first_hop_htlc_msat)
 459         } else { unreachable!() };
 460
 461         // Learnings from the HTLC failure to inform future payment retries and scoring.
 462         struct FailureLearnings {
 463                 network_update: Option<NetworkUpdate>,
 464                 short_channel_id: Option<u64>,
 465                 payment_failed_permanently: bool,
 466         }
 467         let mut res: Option<FailureLearnings> = None;
 468         let mut htlc_msat = *first_hop_htlc_msat;
 469         let mut error_code_ret = None;
 470         let mut error_packet_ret = None;
 471         let mut is_from_final_node = false;
 472
 473         const BADONION: u16 = 0x8000;
 474         const PERM: u16 = 0x4000;
 475         const NODE: u16 = 0x2000;
 476         const UPDATE: u16 = 0x1000;
 477
 478         // Handle packed channel/node updates for passing back for the route handler
 479         construct_onion_keys_callback(secp_ctx, &path, session_priv,
 480                 |shared_secret, _, _, route_hop_opt, route_hop_idx|
 481         {
 482                 if res.is_some() { return; }
 483
 484                 let route_hop = match route_hop_opt {
 485                         Some(hop) => hop,
 486                         None => {
 487                                 // Got an error from within a blinded route.
 488                                 error_code_ret = Some(BADONION | PERM | 24); // invalid_onion_blinding
 489                                 error_packet_ret = Some(vec![0; 32]);
 490                                 res = Some(FailureLearnings {
 491                                         network_update: None, short_channel_id: None, payment_failed_permanently: false
 492                                 });
 493                                 return
 494                         },
 495                 };
 496
 497                 // The failing hop includes either the inbound channel to the recipient or the outbound channel
 498                 // from the current hop (i.e., the next hop's inbound channel).
 499                 let num_blinded_hops = path.blinded_tail.as_ref().map_or(0, |bt| bt.hops.len());
 500                 // For 1-hop blinded paths, the final `path.hops` entry is the recipient.
 501                 is_from_final_node = route_hop_idx + 1 == path.hops.len() && num_blinded_hops <= 1;
 502                 let failing_route_hop = if is_from_final_node { route_hop } else {
 503                         match path.hops.get(route_hop_idx + 1) {
 504                                 Some(hop) => hop,
 505                                 None => {
 506                                         // The failing hop is within a multi-hop blinded path.
 507                                         #[cfg(not(test))] {
 508                                                 error_code_ret = Some(BADONION | PERM | 24); // invalid_onion_blinding
 509                                                 error_packet_ret = Some(vec![0; 32]);
 510                                         }
 511                                         #[cfg(test)] {
 512                                                 // Actually parse the onion error data in tests so we can check that blinded hops fail
 513                                                 // back correctly.
 514                                                 let err_packet = decrypt_onion_error_packet(
 515                                                         &mut encrypted_packet, shared_secret
 516                                                 ).unwrap();
 517                                                 error_code_ret =
 518                                                         Some(u16::from_be_bytes(err_packet.failuremsg.get(0..2).unwrap().try_into().unwrap()));
 519                                                 error_packet_ret = Some(err_packet.failuremsg[2..].to_vec());
 520                                         }
 521
 522                                         res = Some(FailureLearnings {
 523                                                 network_update: None, short_channel_id: None, payment_failed_permanently: false
 524                                         });
 525                                         return
 526                                 }
 527                         }
 528                 };
 529
 530                 let amt_to_forward = htlc_msat - route_hop.fee_msat;
 531                 htlc_msat = amt_to_forward;
 532
 533                 let err_packet = match decrypt_onion_error_packet(&mut encrypted_packet, shared_secret) {
 534                         Ok(p) => p,
 535                         Err(_) => return
 536                 };
 537                 let um = gen_um_from_shared_secret(shared_secret.as_ref());
 538                 let mut hmac = HmacEngine::<Sha256>::new(&um);
 539                 hmac.input(&err_packet.encode()[32..]);
 540
 541                 if !fixed_time_eq(&Hmac::from_engine(hmac).to_byte_array(), &err_packet.hmac) { return }
 542                 let error_code_slice = match err_packet.failuremsg.get(0..2) {
 543                         Some(s) => s,
 544                         None => {
 545                                 // Useless packet that we can't use but it passed HMAC, so it definitely came from the peer
 546                                 // in question
 547                                 let network_update = Some(NetworkUpdate::NodeFailure {
 548                                         node_id: route_hop.pubkey,
 549                                         is_permanent: true,
 550                                 });
 551                                 let short_channel_id = Some(route_hop.short_channel_id);
 552                                 res = Some(FailureLearnings {
 553                                         network_update, short_channel_id, payment_failed_permanently: is_from_final_node
 554                                 });
 555                                 return
 556                         }
 557                 };
 558
 559                 let error_code = u16::from_be_bytes(error_code_slice.try_into().expect("len is 2"));
 560                 error_code_ret = Some(error_code);
 561                 error_packet_ret = Some(err_packet.failuremsg[2..].to_vec());
 562
 563                 let (debug_field, debug_field_size) = errors::get_onion_debug_field(error_code);
 564
 565                 // indicate that payment parameter has failed and no need to update Route object
 566                 let payment_failed = match error_code & 0xff {
 567                         15|16|17|18|19|23 => true,
 568                         _ => false,
 569                 } && is_from_final_node; // PERM bit observed below even if this error is from the intermediate nodes
 570
 571                 let mut network_update = None;
 572                 let mut short_channel_id = None;
 573
 574                 if error_code & BADONION == BADONION {
 575                         // If the error code has the BADONION bit set, always blame the channel from the node
 576                         // "originating" the error to its next hop. The "originator" is ultimately actually claiming
 577                         // that its counterparty is the one who is failing the HTLC.
 578                         // If the "originator" here isn't lying we should really mark the next-hop node as failed
 579                         // entirely, but we can't be confident in that, as it would allow any node to get us to
 580                         // completely ban one of its counterparties. Instead, we simply remove the channel in
 581                         // question.
 582                         network_update = Some(NetworkUpdate::ChannelFailure {
 583                                 short_channel_id: failing_route_hop.short_channel_id,
 584                                 is_permanent: true,
 585                         });
 586                 } else if error_code & NODE == NODE {
 587                         let is_permanent = error_code & PERM == PERM;
 588                         network_update = Some(NetworkUpdate::NodeFailure { node_id: route_hop.pubkey, is_permanent });
 589                         short_channel_id = Some(route_hop.short_channel_id);
 590                 } else if error_code & PERM == PERM {
 591                         if !payment_failed {
 592                                 network_update = Some(NetworkUpdate::ChannelFailure {
 593                                         short_channel_id: failing_route_hop.short_channel_id,
 594                                         is_permanent: true,
 595                                 });
 596                                 short_channel_id = Some(failing_route_hop.short_channel_id);
 597                         }
 598                 } else if error_code & UPDATE == UPDATE {
 599                         if let Some(update_len_slice) = err_packet.failuremsg.get(debug_field_size+2..debug_field_size+4) {
 600                                 let update_len = u16::from_be_bytes(update_len_slice.try_into().expect("len is 2")) as usize;
 601                                 if let Some(mut update_slice) = err_packet.failuremsg.get(debug_field_size + 4..debug_field_size + 4 + update_len) {
 602                                         // Historically, the BOLTs were unclear if the message type
 603                                         // bytes should be included here or not. The BOLTs have now
 604                                         // been updated to indicate that they *are* included, but many
 605                                         // nodes still send messages without the type bytes, so we
 606                                         // support both here.
 607                                         // TODO: Switch to hard require the type prefix, as the current
 608                                         // permissiveness introduces the (although small) possibility
 609                                         // that we fail to decode legitimate channel updates that
 610                                         // happen to start with ChannelUpdate::TYPE, i.e., [0x01, 0x02].
 611                                         if update_slice.len() > 2 && update_slice[0..2] == msgs::ChannelUpdate::TYPE.to_be_bytes() {
 612                                                 update_slice = &update_slice[2..];
 613                                         } else {
 614                                                 log_trace!(logger, "Failure provided features a channel update without type prefix. Deprecated, but allowing for now.");
 615                                         }
 616                                         let update_opt = msgs::ChannelUpdate::read(&mut Cursor::new(&update_slice));
 617                                         if update_opt.is_ok() || update_slice.is_empty() {
 618                                                 // if channel_update should NOT have caused the failure:
 619                                                 // MAY treat the channel_update as invalid.
 620                                                 let is_chan_update_invalid = match error_code & 0xff {
 621                                                         7 => false,
 622                                                         11 => update_opt.is_ok() &&
 623                                                                 amt_to_forward >
 624                                                                         update_opt.as_ref().unwrap().contents.htlc_minimum_msat,
 625                                                         12 => update_opt.is_ok() && amt_to_forward
 626                                                                 .checked_mul(update_opt.as_ref().unwrap()
 627                                                                         .contents.fee_proportional_millionths as u64)
 628                                                                 .map(|prop_fee| prop_fee / 1_000_000)
 629                                                                 .and_then(|prop_fee| prop_fee.checked_add(
 630                                                                         update_opt.as_ref().unwrap().contents.fee_base_msat as u64))
 631                                                                 .map(|fee_msats| route_hop.fee_msat >= fee_msats)
 632                                                                 .unwrap_or(false),
 633                                                         13 => update_opt.is_ok() &&
 634                                                                 route_hop.cltv_expiry_delta as u16 >=
 635                                                                         update_opt.as_ref().unwrap().contents.cltv_expiry_delta,
 636                                                         14 => false, // expiry_too_soon; always valid?
 637                                                         20 => update_opt.as_ref().unwrap().contents.flags & 2 == 0,
 638                                                         _ => false, // unknown error code; take channel_update as valid
 639                                                 };
 640                                                 if is_chan_update_invalid {
 641                                                         // This probably indicates the node which forwarded
 642                                                         // to the node in question corrupted something.
 643                                                         network_update = Some(NetworkUpdate::ChannelFailure {
 644                                                                 short_channel_id: route_hop.short_channel_id,
 645                                                                 is_permanent: true,
 646                                                         });
 647                                                 } else {
 648                                                         if let Ok(chan_update) = update_opt {
 649                                                                 // Make sure the ChannelUpdate contains the expected
 650                                                                 // short channel id.
 651                                                                 if failing_route_hop.short_channel_id == chan_update.contents.short_channel_id {
 652                                                                         short_channel_id = Some(failing_route_hop.short_channel_id);
 653                                                                 } else {
 654                                                                         log_info!(logger, "Node provided a channel_update for which it was not authoritative, ignoring.");
 655                                                                 }
 656                                                                 network_update = Some(NetworkUpdate::ChannelUpdateMessage {
 657                                                                         msg: chan_update,
 658                                                                 })
 659                                                         } else {
 660                                                                 // The node in question intentionally encoded a 0-length channel update. This is
 661                                                                 // likely due to https://github.com/ElementsProject/lightning/issues/6200.
 662                                                                 short_channel_id = Some(failing_route_hop.short_channel_id);
 663                                                                 network_update = Some(NetworkUpdate::ChannelFailure {
 664                                                                         short_channel_id: failing_route_hop.short_channel_id,
 665                                                                         is_permanent: false,
 666                                                                 });
 667                                                         }
 668                                                 };
 669                                         } else {
 670                                                 // If the channel_update had a non-zero length (i.e. was
 671                                                 // present) but we couldn't read it, treat it as a total
 672                                                 // node failure.
 673                                                 log_info!(logger,
 674                                                         "Failed to read a channel_update of len {} in an onion",
 675                                                         update_slice.len());
 676                                         }
 677                                 }
 678                         }
 679                         if network_update.is_none() {
 680                                 // They provided an UPDATE which was obviously bogus, not worth
 681                                 // trying to relay through them anymore.
 682                                 network_update = Some(NetworkUpdate::NodeFailure {
 683                                         node_id: route_hop.pubkey,
 684                                         is_permanent: true,
 685                                 });
 686                         }
 687                         if short_channel_id.is_none() {
 688                                 short_channel_id = Some(route_hop.short_channel_id);
 689                         }
 690                 } else if payment_failed {
 691                         // Only blame the hop when a value in the HTLC doesn't match the corresponding value in the
 692                         // onion.
 693                         short_channel_id = match error_code & 0xff {
 694                                 18|19 => Some(route_hop.short_channel_id),
 695                                 _ => None,
 696                         };
 697                 } else {
 698                         // We can't understand their error messages and they failed to forward...they probably can't
 699                         // understand our forwards so it's really not worth trying any further.
 700                         network_update = Some(NetworkUpdate::NodeFailure {
 701                                 node_id: route_hop.pubkey,
 702                                 is_permanent: true,
 703                         });
 704                         short_channel_id = Some(route_hop.short_channel_id);
 705                 }
 706
 707                 res = Some(FailureLearnings {
 708                         network_update, short_channel_id,
 709                         payment_failed_permanently: error_code & PERM == PERM && is_from_final_node
 710                 });
 711
 712                 let (description, title) = errors::get_onion_error_description(error_code);
 713                 if debug_field_size > 0 && err_packet.failuremsg.len() >= 4 + debug_field_size {
 714                         log_info!(logger, "Onion Error[from {}: {}({:#x}) {}({})] {}", route_hop.pubkey, title, error_code, debug_field, log_bytes!(&err_packet.failuremsg[4..4+debug_field_size]), description);
 715                 } else {
 716                         log_info!(logger, "Onion Error[from {}: {}({:#x})] {}", route_hop.pubkey, title, error_code, description);
 717                 }
 718         }).expect("Route that we sent via spontaneously grew invalid keys in the middle of it?");
 719         if let Some(FailureLearnings {
 720                 network_update, short_channel_id, payment_failed_permanently
 721         }) = res {
 722                 DecodedOnionFailure {
 723                         network_update, short_channel_id, payment_failed_permanently,
 724                         #[cfg(test)]
 725                         onion_error_code: error_code_ret,
 726                         #[cfg(test)]
 727                         onion_error_data: error_packet_ret
 728                 }
 729         } else {
 730                 // only not set either packet unparseable or hmac does not match with any
 731                 // payment not retryable only when garbage is from the final node
 732                 DecodedOnionFailure {
 733                         network_update: None, short_channel_id: None, payment_failed_permanently: is_from_final_node,
 734                         #[cfg(test)]
 735                         onion_error_code: None,
 736                         #[cfg(test)]
 737                         onion_error_data: None
 738                 }
 739         }
 740 }
 741
 742 #[derive(Clone)] // See Channel::revoke_and_ack for why, tl;dr: Rust bug
 743 #[cfg_attr(test, derive(PartialEq))]
 744 pub(super) struct HTLCFailReason(HTLCFailReasonRepr);
 745
 746 #[derive(Clone)] // See Channel::revoke_and_ack for why, tl;dr: Rust bug
 747 #[cfg_attr(test, derive(PartialEq))]
 748 enum HTLCFailReasonRepr {
 749         LightningError {
 750                 err: msgs::OnionErrorPacket,
 751         },
 752         Reason {
 753                 failure_code: u16,
 754                 data: Vec<u8>,
 755         }
 756 }
 757
 758 impl core::fmt::Debug for HTLCFailReason {
 759         fn fmt(&self, f: &mut core::fmt::Formatter) -> Result<(), core::fmt::Error> {
 760                 match self.0 {
 761                         HTLCFailReasonRepr::Reason { ref failure_code, .. } => {
 762                                 write!(f, "HTLC error code {}", failure_code)
 763                         },
 764                         HTLCFailReasonRepr::LightningError { .. } => {
 765                                 write!(f, "pre-built LightningError")
 766                         }
 767                 }
 768         }
 769 }
 770
 771 impl Writeable for HTLCFailReason {
 772         fn write<W: Writer>(&self, writer: &mut W) -> Result<(), crate::io::Error> {
 773                 self.0.write(writer)
 774         }
 775 }
 776 impl Readable for HTLCFailReason {
 777         fn read<R: Read>(reader: &mut R) -> Result<Self, msgs::DecodeError> {
 778                 Ok(Self(Readable::read(reader)?))
 779         }
 780 }
 781
 782 impl_writeable_tlv_based_enum!(HTLCFailReasonRepr,
 783         (0, LightningError) => {
 784                 (0, err, required),
 785         },
 786         (1, Reason) => {
 787                 (0, failure_code, required),
 788                 (2, data, required_vec),
 789         },
 790 ;);
 791
 792 impl HTLCFailReason {
 793         pub(super) fn reason(failure_code: u16, data: Vec<u8>) -> Self {
 794                 const BADONION: u16 = 0x8000;
 795                 const PERM: u16 = 0x4000;
 796                 const NODE: u16 = 0x2000;
 797                 const UPDATE: u16 = 0x1000;
 798
 799                      if failure_code == 1  | PERM { debug_assert!(data.is_empty()) }
 800                 else if failure_code == 2  | NODE { debug_assert!(data.is_empty()) }
 801                 else if failure_code == 2  | PERM | NODE { debug_assert!(data.is_empty()) }
 802                 else if failure_code == 3  | PERM | NODE { debug_assert!(data.is_empty()) }
 803                 else if failure_code == 4  | BADONION | PERM { debug_assert_eq!(data.len(), 32) }
 804                 else if failure_code == 5  | BADONION | PERM { debug_assert_eq!(data.len(), 32) }
 805                 else if failure_code == 6  | BADONION | PERM { debug_assert_eq!(data.len(), 32) }
 806                 else if failure_code == 7  | UPDATE {
 807                         debug_assert_eq!(data.len() - 2, u16::from_be_bytes(data[0..2].try_into().unwrap()) as usize) }
 808                 else if failure_code == 8  | PERM { debug_assert!(data.is_empty()) }
 809                 else if failure_code == 9  | PERM { debug_assert!(data.is_empty()) }
 810                 else if failure_code == 10 | PERM { debug_assert!(data.is_empty()) }
 811                 else if failure_code == 11 | UPDATE {
 812                         debug_assert_eq!(data.len() - 2 - 8, u16::from_be_bytes(data[8..10].try_into().unwrap()) as usize) }
 813                 else if failure_code == 12 | UPDATE {
 814                         debug_assert_eq!(data.len() - 2 - 8, u16::from_be_bytes(data[8..10].try_into().unwrap()) as usize) }
 815                 else if failure_code == 13 | UPDATE {
 816                         debug_assert_eq!(data.len() - 2 - 4, u16::from_be_bytes(data[4..6].try_into().unwrap()) as usize) }
 817                 else if failure_code == 14 | UPDATE {
 818                         debug_assert_eq!(data.len() - 2, u16::from_be_bytes(data[0..2].try_into().unwrap()) as usize) }
 819                 else if failure_code == 15 | PERM { debug_assert_eq!(data.len(), 12) }
 820                 else if failure_code == 18 { debug_assert_eq!(data.len(), 4) }
 821                 else if failure_code == 19 { debug_assert_eq!(data.len(), 8) }
 822                 else if failure_code == 20 | UPDATE {
 823                         debug_assert_eq!(data.len() - 2 - 2, u16::from_be_bytes(data[2..4].try_into().unwrap()) as usize) }
 824                 else if failure_code == 21 { debug_assert!(data.is_empty()) }
 825                 else if failure_code == 22 | PERM { debug_assert!(data.len() <= 11) }
 826                 else if failure_code == 23 { debug_assert!(data.is_empty()) }
 827                 else if failure_code & BADONION != 0 {
 828                         // We set some bogus BADONION failure codes in test, so ignore unknown ones.
 829                 }
 830                 else { debug_assert!(false, "Unknown failure code: {}", failure_code) }
 831
 832                 Self(HTLCFailReasonRepr::Reason { failure_code, data })
 833         }
 834
 835         pub(super) fn from_failure_code(failure_code: u16) -> Self {
 836                 Self::reason(failure_code, Vec::new())
 837         }
 838
 839         pub(super) fn from_msg(msg: &msgs::UpdateFailHTLC) -> Self {
 840                 Self(HTLCFailReasonRepr::LightningError { err: msg.reason.clone() })
 841         }
 842
 843         pub(super) fn get_encrypted_failure_packet(&self, incoming_packet_shared_secret: &[u8; 32], phantom_shared_secret: &Option<[u8; 32]>)
 844         -> msgs::OnionErrorPacket {
 845                 match self.0 {
 846                         HTLCFailReasonRepr::Reason { ref failure_code, ref data } => {
 847                                 if let Some(phantom_ss) = phantom_shared_secret {
 848                                         let phantom_packet = build_failure_packet(phantom_ss, *failure_code, &data[..]).encode();
 849                                         let encrypted_phantom_packet = encrypt_failure_packet(phantom_ss, &phantom_packet);
 850                                         encrypt_failure_packet(incoming_packet_shared_secret, &encrypted_phantom_packet.data[..])
 851                                 } else {
 852                                         let packet = build_failure_packet(incoming_packet_shared_secret, *failure_code, &data[..]).encode();
 853                                         encrypt_failure_packet(incoming_packet_shared_secret, &packet)
 854                                 }
 855                         },
 856                         HTLCFailReasonRepr::LightningError { ref err } => {
 857                                 encrypt_failure_packet(incoming_packet_shared_secret, &err.data)
 858                         }
 859                 }
 860         }
 861
 862         pub(super) fn decode_onion_failure<T: secp256k1::Signing, L: Deref>(
 863                 &self, secp_ctx: &Secp256k1<T>, logger: &L, htlc_source: &HTLCSource
 864         ) -> DecodedOnionFailure where L::Target: Logger {
 865                 match self.0 {
 866                         HTLCFailReasonRepr::LightningError { ref err } => {
 867                                 process_onion_failure(secp_ctx, logger, &htlc_source, err.data.clone())
 868                         },
 869                         #[allow(unused)]
 870                         HTLCFailReasonRepr::Reason { ref failure_code, ref data, .. } => {
 871                                 // we get a fail_malformed_htlc from the first hop
 872                                 // TODO: We'd like to generate a NetworkUpdate for temporary
 873                                 // failures here, but that would be insufficient as find_route
 874                                 // generally ignores its view of our own channels as we provide them via
 875                                 // ChannelDetails.
 876                                 if let &HTLCSource::OutboundRoute { ref path, .. } = htlc_source {
 877                                         DecodedOnionFailure {
 878                                                 network_update: None,
 879                                                 payment_failed_permanently: false,
 880                                                 short_channel_id: Some(path.hops[0].short_channel_id),
 881                                                 #[cfg(test)]
 882                                                 onion_error_code: Some(*failure_code),
 883                                                 #[cfg(test)]
 884                                                 onion_error_data: Some(data.clone()),
 885                                         }
 886                                 } else { unreachable!(); }
 887                         }
 888                 }
 889         }
 890 }
 891
 892 /// Allows `decode_next_hop` to return the next hop packet bytes for either payments or onion
 893 /// message forwards.
 894 pub(crate) trait NextPacketBytes: AsMut<[u8]> {
 895         fn new(len: usize) -> Self;
 896 }
 897
 898 impl NextPacketBytes for FixedSizeOnionPacket {
 899         fn new(_len: usize) -> Self  {
 900                 Self([0 as u8; ONION_DATA_LEN])
 901         }
 902 }
 903
 904 impl NextPacketBytes for Vec<u8> {
 905         fn new(len: usize) -> Self {
 906                 vec![0 as u8; len]
 907         }
 908 }
 909
 910 /// Data decrypted from a payment's onion payload.
 911 pub(crate) enum Hop {
 912         /// This onion payload was for us, not for forwarding to a next-hop. Contains information for
 913         /// verifying the incoming payment.
 914         Receive(msgs::InboundOnionPayload),
 915         /// This onion payload needs to be forwarded to a next-hop.
 916         Forward {
 917                 /// Onion payload data used in forwarding the payment.
 918                 next_hop_data: msgs::InboundOnionPayload,
 919                 /// HMAC of the next hop's onion packet.
 920                 next_hop_hmac: [u8; 32],
 921                 /// Bytes of the onion packet we're forwarding.
 922                 new_packet_bytes: [u8; ONION_DATA_LEN],
 923         },
 924 }
 925
 926 /// Error returned when we fail to decode the onion packet.
 927 #[derive(Debug)]
 928 pub(crate) enum OnionDecodeErr {
 929         /// The HMAC of the onion packet did not match the hop data.
 930         Malformed {
 931                 err_msg: &'static str,
 932                 err_code: u16,
 933         },
 934         /// We failed to decode the onion payload.
 935         Relay {
 936                 err_msg: &'static str,
 937                 err_code: u16,
 938         },
 939 }
 940
 941 pub(crate) fn decode_next_payment_hop<NS: Deref>(
 942         shared_secret: [u8; 32], hop_data: &[u8], hmac_bytes: [u8; 32], payment_hash: PaymentHash,
 943         blinding_point: Option<PublicKey>, node_signer: &NS,
 944 ) -> Result<Hop, OnionDecodeErr> where NS::Target: NodeSigner {
 945         match decode_next_hop(
 946                 shared_secret, hop_data, hmac_bytes, Some(payment_hash), (blinding_point, node_signer)
 947         ) {
 948                 Ok((next_hop_data, None)) => Ok(Hop::Receive(next_hop_data)),
 949                 Ok((next_hop_data, Some((next_hop_hmac, FixedSizeOnionPacket(new_packet_bytes))))) => {
 950                         Ok(Hop::Forward {
 951                                 next_hop_data,
 952                                 next_hop_hmac,
 953                                 new_packet_bytes
 954                         })
 955                 },
 956                 Err(e) => Err(e),
 957         }
 958 }
 959
 960 /// Build a payment onion, returning the first hop msat and cltv values as well.
 961 /// `cur_block_height` should be set to the best known block height + 1.
 962 pub fn create_payment_onion<T: secp256k1::Signing>(
 963         secp_ctx: &Secp256k1<T>, path: &Path, session_priv: &SecretKey, total_msat: u64,
 964         recipient_onion: RecipientOnionFields, cur_block_height: u32, payment_hash: &PaymentHash,
 965         keysend_preimage: &Option<PaymentPreimage>, prng_seed: [u8; 32]
 966 ) -> Result<(msgs::OnionPacket, u64, u32), APIError> {
 967         let onion_keys = construct_onion_keys(&secp_ctx, &path, &session_priv)
 968                 .map_err(|_| APIError::InvalidRoute{
 969                         err: "Pubkey along hop was maliciously selected".to_owned()
 970                 })?;
 971         let (onion_payloads, htlc_msat, htlc_cltv) = build_onion_payloads(
 972                 &path, total_msat, recipient_onion, cur_block_height, keysend_preimage
 973         )?;
 974         let onion_packet = construct_onion_packet(onion_payloads, onion_keys, prng_seed, payment_hash)
 975                 .map_err(|_| APIError::InvalidRoute{
 976                         err: "Route size too large considering onion data".to_owned()
 977                 })?;
 978         Ok((onion_packet, htlc_msat, htlc_cltv))
 979 }
 980
 981 pub(crate) fn decode_next_untagged_hop<T, R: ReadableArgs<T>, N: NextPacketBytes>(shared_secret: [u8; 32], hop_data: &[u8], hmac_bytes: [u8; 32], read_args: T) -> Result<(R, Option<([u8; 32], N)>), OnionDecodeErr> {
 982         decode_next_hop(shared_secret, hop_data, hmac_bytes, None, read_args)
 983 }
 984
 985 fn decode_next_hop<T, R: ReadableArgs<T>, N: NextPacketBytes>(shared_secret: [u8; 32], hop_data: &[u8], hmac_bytes: [u8; 32], payment_hash: Option<PaymentHash>, read_args: T) -> Result<(R, Option<([u8; 32], N)>), OnionDecodeErr> {
 986         let (rho, mu) = gen_rho_mu_from_shared_secret(&shared_secret);
 987         let mut hmac = HmacEngine::<Sha256>::new(&mu);
 988         hmac.input(hop_data);
 989         if let Some(tag) = payment_hash {
 990                 hmac.input(&tag.0[..]);
 991         }
 992         if !fixed_time_eq(&Hmac::from_engine(hmac).to_byte_array(), &hmac_bytes) {
 993                 return Err(OnionDecodeErr::Malformed {
 994                         err_msg: "HMAC Check failed",
 995                         err_code: 0x8000 | 0x4000 | 5,
 996                 });
 997         }
 998
 999         let mut chacha = ChaCha20::new(&rho, &[0u8; 8]);
1000         let mut chacha_stream = ChaChaReader { chacha: &mut chacha, read: Cursor::new(&hop_data[..]) };
1001         match R::read(&mut chacha_stream, read_args) {
1002                 Err(err) => {
1003                         let error_code = match err {
1004                                 msgs::DecodeError::UnknownVersion => 0x4000 | 1, // unknown realm byte
1005                                 msgs::DecodeError::UnknownRequiredFeature|
1006                                 msgs::DecodeError::InvalidValue|
1007                                 msgs::DecodeError::ShortRead => 0x4000 | 22, // invalid_onion_payload
1008                                 _ => 0x2000 | 2, // Should never happen
1009                         };
1010                         return Err(OnionDecodeErr::Relay {
1011                                 err_msg: "Unable to decode our hop data",
1012                                 err_code: error_code,
1013                         });
1014                 },
1015                 Ok(msg) => {
1016                         let mut hmac = [0; 32];
1017                         if let Err(_) = chacha_stream.read_exact(&mut hmac[..]) {
1018                                 return Err(OnionDecodeErr::Relay {
1019                                         err_msg: "Unable to decode our hop data",
1020                                         err_code: 0x4000 | 22,
1021                                 });
1022                         }
1023                         if hmac == [0; 32] {
1024                                 #[cfg(test)]
1025                                 {
1026                                         if chacha_stream.read.position() < hop_data.len() as u64 - 64 {
1027                                                 // In tests, make sure that the initial onion packet data is, at least, non-0.
1028                                                 // We could do some fancy randomness test here, but, ehh, whatever.
1029                                                 // This checks for the issue where you can calculate the path length given the
1030                                                 // onion data as all the path entries that the originator sent will be here
1031                                                 // as-is (and were originally 0s).
1032                                                 // Of course reverse path calculation is still pretty easy given naive routing
1033                                                 // algorithms, but this fixes the most-obvious case.
1034                                                 let mut next_bytes = [0; 32];
1035                                                 chacha_stream.read_exact(&mut next_bytes).unwrap();
1036                                                 assert_ne!(next_bytes[..], [0; 32][..]);
1037                                                 chacha_stream.read_exact(&mut next_bytes).unwrap();
1038                                                 assert_ne!(next_bytes[..], [0; 32][..]);
1039                                         }
1040                                 }
1041                                 return Ok((msg, None)); // We are the final destination for this packet
1042                         } else {
1043                                 let mut new_packet_bytes = N::new(hop_data.len());
1044                                 let read_pos = hop_data.len() - chacha_stream.read.position() as usize;
1045                                 chacha_stream.read_exact(&mut new_packet_bytes.as_mut()[..read_pos]).unwrap();
1046                                 #[cfg(debug_assertions)]
1047                                 {
1048                                         // Check two things:
1049                                         // a) that the behavior of our stream here will return Ok(0) even if the TLV
1050                                         //    read above emptied out our buffer and the unwrap() wont needlessly panic
1051                                         // b) that we didn't somehow magically end up with extra data.
1052                                         let mut t = [0; 1];
1053                                         debug_assert!(chacha_stream.read(&mut t).unwrap() == 0);
1054                                 }
1055                                 // Once we've emptied the set of bytes our peer gave us, encrypt 0 bytes until we
1056                                 // fill the onion hop data we'll forward to our next-hop peer.
1057                                 chacha_stream.chacha.process_in_place(&mut new_packet_bytes.as_mut()[read_pos..]);
1058                                 return Ok((msg, Some((hmac, new_packet_bytes)))) // This packet needs forwarding
1059                         }
1060                 },
1061         }
1062 }
1063
1064 #[cfg(test)]
1065 mod tests {
1066         use crate::io;
1067         use crate::prelude::*;
1068         use crate::ln::PaymentHash;
1069         use crate::ln::features::{ChannelFeatures, NodeFeatures};
1070         use crate::routing::router::{Path, Route, RouteHop};
1071         use crate::ln::msgs;
1072         use crate::util::ser::{Writeable, Writer, VecWriter};
1073
1074         use bitcoin::hashes::hex::FromHex;
1075         use bitcoin::secp256k1::Secp256k1;
1076         use bitcoin::secp256k1::{PublicKey,SecretKey};
1077
1078         use super::OnionKeys;
1079
1080         fn get_test_session_key() -> SecretKey {
1081                 SecretKey::from_slice(&<Vec<u8>>::from_hex("4141414141414141414141414141414141414141414141414141414141414141").unwrap()[..]).unwrap()
1082         }
1083
1084         fn build_test_onion_keys() -> Vec<OnionKeys> {
1085                 // Keys from BOLT 4, used in both test vector tests
1086                 let secp_ctx = Secp256k1::new();
1087
1088                 let route = Route {
1089                         paths: vec![Path { hops: vec![
1090                                         RouteHop {
1091                                                 pubkey: PublicKey::from_slice(&<Vec<u8>>::from_hex("02eec7245d6b7d2ccb30380bfbe2a3648cd7a942653f5aa340edcea1f283686619").unwrap()[..]).unwrap(),
1092                                                 channel_features: ChannelFeatures::empty(), node_features: NodeFeatures::empty(),
1093                                                 short_channel_id: 0, fee_msat: 0, cltv_expiry_delta: 0, maybe_announced_channel: true, // We fill in the payloads manually instead of generating them from RouteHops.
1094                                         },
1095                                         RouteHop {
1096                                                 pubkey: PublicKey::from_slice(&<Vec<u8>>::from_hex("0324653eac434488002cc06bbfb7f10fe18991e35f9fe4302dbea6d2353dc0ab1c").unwrap()[..]).unwrap(),
1097                                                 channel_features: ChannelFeatures::empty(), node_features: NodeFeatures::empty(),
1098                                                 short_channel_id: 0, fee_msat: 0, cltv_expiry_delta: 0, maybe_announced_channel: true, // We fill in the payloads manually instead of generating them from RouteHops.
1099                                         },
1100                                         RouteHop {
1101                                                 pubkey: PublicKey::from_slice(&<Vec<u8>>::from_hex("027f31ebc5462c1fdce1b737ecff52d37d75dea43ce11c74d25aa297165faa2007").unwrap()[..]).unwrap(),
1102                                                 channel_features: ChannelFeatures::empty(), node_features: NodeFeatures::empty(),
1103                                                 short_channel_id: 0, fee_msat: 0, cltv_expiry_delta: 0, maybe_announced_channel: true, // We fill in the payloads manually instead of generating them from RouteHops.
1104                                         },
1105                                         RouteHop {
1106                                                 pubkey: PublicKey::from_slice(&<Vec<u8>>::from_hex("032c0b7cf95324a07d05398b240174dc0c2be444d96b159aa6c7f7b1e668680991").unwrap()[..]).unwrap(),
1107                                                 channel_features: ChannelFeatures::empty(), node_features: NodeFeatures::empty(),
1108                                                 short_channel_id: 0, fee_msat: 0, cltv_expiry_delta: 0, maybe_announced_channel: true, // We fill in the payloads manually instead of generating them from RouteHops.
1109                                         },
1110                                         RouteHop {
1111                                                 pubkey: PublicKey::from_slice(&<Vec<u8>>::from_hex("02edabbd16b41c8371b92ef2f04c1185b4f03b6dcd52ba9b78d9d7c89c8f221145").unwrap()[..]).unwrap(),
1112                                                 channel_features: ChannelFeatures::empty(), node_features: NodeFeatures::empty(),
1113                                                 short_channel_id: 0, fee_msat: 0, cltv_expiry_delta: 0, maybe_announced_channel: true, // We fill in the payloads manually instead of generating them from RouteHops.
1114                                         },
1115                         ], blinded_tail: None }],
1116                         route_params: None,
1117                 };
1118
1119                 let onion_keys = super::construct_onion_keys(&secp_ctx, &route.paths[0], &get_test_session_key()).unwrap();
1120                 assert_eq!(onion_keys.len(), route.paths[0].hops.len());
1121                 onion_keys
1122         }
1123
1124         #[test]
1125         fn onion_vectors() {
1126                 let onion_keys = build_test_onion_keys();
1127
1128                 // Test generation of ephemeral keys and secrets. These values used to be part of the BOLT4
1129                 // test vectors, but have since been removed. We keep them as they provide test coverage.
1130                 assert_eq!(onion_keys[0].shared_secret.secret_bytes(), <Vec<u8>>::from_hex("53eb63ea8a3fec3b3cd433b85cd62a4b145e1dda09391b348c4e1cd36a03ea66").unwrap()[..]);
1131                 assert_eq!(onion_keys[0].blinding_factor[..], <Vec<u8>>::from_hex("2ec2e5da605776054187180343287683aa6a51b4b1c04d6dd49c45d8cffb3c36").unwrap()[..]);
1132                 assert_eq!(onion_keys[0].ephemeral_pubkey.serialize()[..], <Vec<u8>>::from_hex("02eec7245d6b7d2ccb30380bfbe2a3648cd7a942653f5aa340edcea1f283686619").unwrap()[..]);
1133                 assert_eq!(onion_keys[0].rho, <Vec<u8>>::from_hex("ce496ec94def95aadd4bec15cdb41a740c9f2b62347c4917325fcc6fb0453986").unwrap()[..]);
1134                 assert_eq!(onion_keys[0].mu, <Vec<u8>>::from_hex("b57061dc6d0a2b9f261ac410c8b26d64ac5506cbba30267a649c28c179400eba").unwrap()[..]);
1135
1136                 assert_eq!(onion_keys[1].shared_secret.secret_bytes(), <Vec<u8>>::from_hex("a6519e98832a0b179f62123b3567c106db99ee37bef036e783263602f3488fae").unwrap()[..]);
1137                 assert_eq!(onion_keys[1].blinding_factor[..], <Vec<u8>>::from_hex("bf66c28bc22e598cfd574a1931a2bafbca09163df2261e6d0056b2610dab938f").unwrap()[..]);
1138                 assert_eq!(onion_keys[1].ephemeral_pubkey.serialize()[..], <Vec<u8>>::from_hex("028f9438bfbf7feac2e108d677e3a82da596be706cc1cf342b75c7b7e22bf4e6e2").unwrap()[..]);
1139                 assert_eq!(onion_keys[1].rho, <Vec<u8>>::from_hex("450ffcabc6449094918ebe13d4f03e433d20a3d28a768203337bc40b6e4b2c59").unwrap()[..]);
1140                 assert_eq!(onion_keys[1].mu, <Vec<u8>>::from_hex("05ed2b4a3fb023c2ff5dd6ed4b9b6ea7383f5cfe9d59c11d121ec2c81ca2eea9").unwrap()[..]);
1141
1142                 assert_eq!(onion_keys[2].shared_secret.secret_bytes(), <Vec<u8>>::from_hex("3a6b412548762f0dbccce5c7ae7bb8147d1caf9b5471c34120b30bc9c04891cc").unwrap()[..]);
1143                 assert_eq!(onion_keys[2].blinding_factor[..], <Vec<u8>>::from_hex("a1f2dadd184eb1627049673f18c6325814384facdee5bfd935d9cb031a1698a5").unwrap()[..]);
1144                 assert_eq!(onion_keys[2].ephemeral_pubkey.serialize()[..], <Vec<u8>>::from_hex("03bfd8225241ea71cd0843db7709f4c222f62ff2d4516fd38b39914ab6b83e0da0").unwrap()[..]);
1145                 assert_eq!(onion_keys[2].rho, <Vec<u8>>::from_hex("11bf5c4f960239cb37833936aa3d02cea82c0f39fd35f566109c41f9eac8deea").unwrap()[..]);
1146                 assert_eq!(onion_keys[2].mu, <Vec<u8>>::from_hex("caafe2820fa00eb2eeb78695ae452eba38f5a53ed6d53518c5c6edf76f3f5b78").unwrap()[..]);
1147
1148                 assert_eq!(onion_keys[3].shared_secret.secret_bytes(), <Vec<u8>>::from_hex("21e13c2d7cfe7e18836df50872466117a295783ab8aab0e7ecc8c725503ad02d").unwrap()[..]);
1149                 assert_eq!(onion_keys[3].blinding_factor[..], <Vec<u8>>::from_hex("7cfe0b699f35525029ae0fa437c69d0f20f7ed4e3916133f9cacbb13c82ff262").unwrap()[..]);
1150                 assert_eq!(onion_keys[3].ephemeral_pubkey.serialize()[..], <Vec<u8>>::from_hex("031dde6926381289671300239ea8e57ffaf9bebd05b9a5b95beaf07af05cd43595").unwrap()[..]);
1151                 assert_eq!(onion_keys[3].rho, <Vec<u8>>::from_hex("cbe784ab745c13ff5cffc2fbe3e84424aa0fd669b8ead4ee562901a4a4e89e9e").unwrap()[..]);
1152                 assert_eq!(onion_keys[3].mu, <Vec<u8>>::from_hex("5052aa1b3d9f0655a0932e50d42f0c9ba0705142c25d225515c45f47c0036ee9").unwrap()[..]);
1153
1154                 assert_eq!(onion_keys[4].shared_secret.secret_bytes(), <Vec<u8>>::from_hex("b5756b9b542727dbafc6765a49488b023a725d631af688fc031217e90770c328").unwrap()[..]);
1155                 assert_eq!(onion_keys[4].blinding_factor[..], <Vec<u8>>::from_hex("c96e00dddaf57e7edcd4fb5954be5b65b09f17cb6d20651b4e90315be5779205").unwrap()[..]);
1156                 assert_eq!(onion_keys[4].ephemeral_pubkey.serialize()[..], <Vec<u8>>::from_hex("03a214ebd875aab6ddfd77f22c5e7311d7f77f17a169e599f157bbcdae8bf071f4").unwrap()[..]);
1157                 assert_eq!(onion_keys[4].rho, <Vec<u8>>::from_hex("034e18b8cc718e8af6339106e706c52d8df89e2b1f7e9142d996acf88df8799b").unwrap()[..]);
1158                 assert_eq!(onion_keys[4].mu, <Vec<u8>>::from_hex("8e45e5c61c2b24cb6382444db6698727afb063adecd72aada233d4bf273d975a").unwrap()[..]);
1159
1160                 // Packet creation test vectors from BOLT 4 (see
1161                 // https://github.com/lightning/bolts/blob/16973e2b857e853308cafd59e42fa830d75b1642/bolt04/onion-test.json).
1162                 // Note that we represent the test vector payloads 2 and 5 through RawOnionHopData::data
1163                 // with raw hex instead of our in-memory enums, as the payloads contains custom types, and
1164                 // we have no way of representing that with our enums.
1165                 let payloads = vec!(
1166                         RawOnionHopData::new(msgs::OutboundOnionPayload::Forward {
1167                                 short_channel_id: 1,
1168                                 amt_to_forward: 15000,
1169                                 outgoing_cltv_value: 1500,
1170                         }),
1171                         /*
1172                         The second payload is represented by raw hex as it contains custom type data. Content:
1173                         1. length "52" (payload_length 82).
1174
1175                         The first part of the payload has the `NonFinalNode` format, with content as follows:
1176                         2. amt_to_forward "020236b0"
1177                            02 (type amt_to_forward) 02 (length 2) 36b0 (value 14000)
1178                         3. outgoing_cltv_value "04020578"
1179                            04 (type outgoing_cltv_value) 02 (length 2) 0578 (value 1400)
1180                         4. short_channel_id "06080000000000000002"
1181                            06 (type short_channel_id) 08 (length 8) 0000000000000002 (value 2)
1182
1183                         The rest of the payload is custom type data:
1184                         5. custom_record "fd02013c0102030405060708090a0b0c0d0e0f0102030405060708090a0b0c0d0e0f0102030405060708090a0b0c0d0e0f0102030405060708090a0b0c0d0e0f"
1185                         */
1186                         RawOnionHopData {
1187                                 data: <Vec<u8>>::from_hex("52020236b00402057806080000000000000002fd02013c0102030405060708090a0b0c0d0e0f0102030405060708090a0b0c0d0e0f0102030405060708090a0b0c0d0e0f0102030405060708090a0b0c0d0e0f").unwrap(),
1188                         },
1189                         RawOnionHopData::new(msgs::OutboundOnionPayload::Forward {
1190                                 short_channel_id: 3,
1191                                 amt_to_forward: 12500,
1192                                 outgoing_cltv_value: 1250,
1193                         }),
1194                         RawOnionHopData::new(msgs::OutboundOnionPayload::Forward {
1195                                 short_channel_id: 4,
1196                                 amt_to_forward: 10000,
1197                                 outgoing_cltv_value: 1000,
1198                         }),
1199                         /*
1200                         The fifth payload is represented by raw hex as it contains custom type data. Content:
1201                         1. length "fd0110" (payload_length 272).
1202
1203                         The first part of the payload has the `FinalNode` format, with content as follows:
1204                         1. amt_to_forward "02022710"
1205                            02 (type amt_to_forward) 02 (length 2) 2710 (value 10000)
1206                         2. outgoing_cltv_value "040203e8"
1207                            04 (type outgoing_cltv_value) 02 (length 2) 03e8 (value 1000)
1208                         3. payment_data "082224a33562c54507a9334e79f0dc4f17d407e6d7c61f0e2f3d0d38599502f617042710"
1209                            08 (type short_channel_id) 22 (length 34) 24a33562c54507a9334e79f0dc4f17d407e6d7c61f0e2f3d0d38599502f61704 (payment_secret) 2710 (total_msat value 10000)
1210
1211                         The rest of the payload is custom type data:
1212                         4. custom_record "fd012de02a2a2a2a2a2a2a2a2a2a2a2a2a2a2a2a2a2a2a2a2a2a2a2a2a2a2a2a2a2a2a2a2a2a2a2a2a2a2a2a2a2a2a2a2a2a2a2a2a2a2a2a2a2a2a2a2a2a2a2a2a2a2a2a2a2a2a2a2a2a2a2a2a2a2a2a2a2a2a2a2a2a2a2a2a2a2a2a2a2a2a2a2a2a2a2a2a2a2a2a2a2a2a2a2a2a2a2a2a2a2a2a2a2a2a2a2a2a2a2a2a2a2a2a2a2a2a2a2a2a2a2a2a2a2a2a2a2a2a2a2a2a2a2a2a2a2a2a2a2a2a2a2a2a2a2a2a2a2a2a2a2a2a2a2a2a2a2a2a2a2a2a2a2a2a2a2a2a2a2a2a2a2a2a2a2a2a2a2a2a2a2a2a2a2a2a2a2a2a2a2a2a2a2a2a2a2a2a2a2a2a2a2a2a2a2a2a2a2a2a2a2a2a2a"
1213                         */
1214                         RawOnionHopData {
1215                                 data: <Vec<u8>>::from_hex("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").unwrap(),
1216                         },
1217                 );
1218
1219                 // Verify that the serialized OnionHopDataFormat::NonFinalNode tlv payloads matches the test vectors
1220                 let mut w = VecWriter(Vec::new());
1221                 payloads[0].write(&mut w).unwrap();
1222                 let hop_1_serialized_payload = w.0;
1223                 let expected_serialized_hop_1_payload = &<Vec<u8>>::from_hex("1202023a98040205dc06080000000000000001").unwrap()[..];
1224                 assert_eq!(hop_1_serialized_payload, expected_serialized_hop_1_payload);
1225
1226                 w = VecWriter(Vec::new());
1227                 payloads[2].write(&mut w).unwrap();
1228                 let hop_3_serialized_payload = w.0;
1229                 let expected_serialized_hop_3_payload = &<Vec<u8>>::from_hex("12020230d4040204e206080000000000000003").unwrap()[..];
1230                 assert_eq!(hop_3_serialized_payload, expected_serialized_hop_3_payload);
1231
1232                 w = VecWriter(Vec::new());
1233                 payloads[3].write(&mut w).unwrap();
1234                 let hop_4_serialized_payload = w.0;
1235                 let expected_serialized_hop_4_payload = &<Vec<u8>>::from_hex("1202022710040203e806080000000000000004").unwrap()[..];
1236                 assert_eq!(hop_4_serialized_payload, expected_serialized_hop_4_payload);
1237
1238                 let pad_keytype_seed = super::gen_pad_from_shared_secret(&get_test_session_key().secret_bytes());
1239
1240                 let packet: msgs::OnionPacket = super::construct_onion_packet_with_writable_hopdata::<_>(payloads, onion_keys, pad_keytype_seed, &PaymentHash([0x42; 32])).unwrap();
1241
1242                 assert_eq!(packet.encode(), <Vec<u8>>::from_hex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unwrap());
1243         }
1244
1245         #[test]
1246         fn test_failure_packet_onion() {
1247                 // Returning Errors test vectors from BOLT 4
1248
1249                 let onion_keys = build_test_onion_keys();
1250                 let onion_error = super::build_failure_packet(onion_keys[4].shared_secret.as_ref(), 0x2002, &[0; 0]);
1251                 assert_eq!(onion_error.encode(), <Vec<u8>>::from_hex("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").unwrap());
1252
1253                 let onion_packet_1 = super::encrypt_failure_packet(onion_keys[4].shared_secret.as_ref(), &onion_error.encode()[..]);
1254                 assert_eq!(onion_packet_1.data, <Vec<u8>>::from_hex("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").unwrap());
1255
1256                 let onion_packet_2 = super::encrypt_failure_packet(onion_keys[3].shared_secret.as_ref(), &onion_packet_1.data[..]);
1257                 assert_eq!(onion_packet_2.data, <Vec<u8>>::from_hex("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").unwrap());
1258
1259                 let onion_packet_3 = super::encrypt_failure_packet(onion_keys[2].shared_secret.as_ref(), &onion_packet_2.data[..]);
1260                 assert_eq!(onion_packet_3.data, <Vec<u8>>::from_hex("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").unwrap());
1261
1262                 let onion_packet_4 = super::encrypt_failure_packet(onion_keys[1].shared_secret.as_ref(), &onion_packet_3.data[..]);
1263                 assert_eq!(onion_packet_4.data, <Vec<u8>>::from_hex("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").unwrap());
1264
1265                 let onion_packet_5 = super::encrypt_failure_packet(onion_keys[0].shared_secret.as_ref(), &onion_packet_4.data[..]);
1266                 assert_eq!(onion_packet_5.data, <Vec<u8>>::from_hex("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").unwrap());
1267         }
1268
1269         struct RawOnionHopData {
1270                 data: Vec<u8>
1271         }
1272         impl RawOnionHopData {
1273                 fn new(orig: msgs::OutboundOnionPayload) -> Self {
1274                         Self { data: orig.encode() }
1275                 }
1276         }
1277         impl Writeable for RawOnionHopData {
1278                 fn write<W: Writer>(&self, writer: &mut W) -> Result<(), io::Error> {
1279                         writer.write_all(&self.data[..])
1280                 }
1281         }
1282 }