_ Git - rust-lightning/blob - lightning/src/ln/peer_channel_encryptor.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::prelude::*;
  11
  12 use crate::chain::keysinterface::{NodeSigner, Recipient};
  13 use crate::ln::msgs::LightningError;
  14 use crate::ln::msgs;
  15 use crate::ln::wire;
  16
  17 use bitcoin::hashes::{Hash, HashEngine};
  18 use bitcoin::hashes::sha256::Hash as Sha256;
  19
  20 use bitcoin::secp256k1::Secp256k1;
  21 use bitcoin::secp256k1::{PublicKey,SecretKey};
  22 use bitcoin::secp256k1::ecdh::SharedSecret;
  23 use bitcoin::secp256k1;
  24
  25 use crate::util::chacha20poly1305rfc::ChaCha20Poly1305RFC;
  26 use crate::util::crypto::hkdf_extract_expand_twice;
  27 use crate::util::ser::VecWriter;
  28 use bitcoin::hashes::hex::ToHex;
  29
  30 use core::ops::Deref;
  31
  32 /// Maximum Lightning message data length according to
  33 /// [BOLT-8](https://github.com/lightning/bolts/blob/v1.0/08-transport.md#lightning-message-specification)
  34 /// and [BOLT-1](https://github.com/lightning/bolts/blob/master/01-messaging.md#lightning-message-format):
  35 pub const LN_MAX_MSG_LEN: usize = ::core::u16::MAX as usize; // Must be equal to 65535
  36
  37 // Sha256("Noise_XK_secp256k1_ChaChaPoly_SHA256")
  38 const NOISE_CK: [u8; 32] = [0x26, 0x40, 0xf5, 0x2e, 0xeb, 0xcd, 0x9e, 0x88, 0x29, 0x58, 0x95, 0x1c, 0x79, 0x42, 0x50, 0xee, 0xdb, 0x28, 0x00, 0x2c, 0x05, 0xd7, 0xdc, 0x2e, 0xa0, 0xf1, 0x95, 0x40, 0x60, 0x42, 0xca, 0xf1];
  39 // Sha256(NOISE_CK || "lightning")
  40 const NOISE_H: [u8; 32] = [0xd1, 0xfb, 0xf6, 0xde, 0xe4, 0xf6, 0x86, 0xf1, 0x32, 0xfd, 0x70, 0x2c, 0x4a, 0xbf, 0x8f, 0xba, 0x4b, 0xb4, 0x20, 0xd8, 0x9d, 0x2a, 0x04, 0x8a, 0x3c, 0x4f, 0x4c, 0x09, 0x2e, 0x37, 0xb6, 0x76];
  41
  42 enum NoiseSecretKey<'a, 'b, NS: Deref> where NS::Target: NodeSigner {
  43         InMemory(&'a SecretKey),
  44         NodeSigner(&'b NS)
  45 }
  46
  47 pub enum NextNoiseStep {
  48         ActOne,
  49         ActTwo,
  50         ActThree,
  51         NoiseComplete,
  52 }
  53
  54 #[derive(PartialEq)]
  55 enum NoiseStep {
  56         PreActOne,
  57         PostActOne,
  58         PostActTwo,
  59         // When done swap noise_state for NoiseState::Finished
  60 }
  61
  62 struct BidirectionalNoiseState {
  63         h: [u8; 32],
  64         ck: [u8; 32],
  65 }
  66 enum DirectionalNoiseState {
  67         Outbound {
  68                 ie: SecretKey,
  69         },
  70         Inbound {
  71                 ie: Option<PublicKey>, // filled in if state >= PostActOne
  72                 re: Option<SecretKey>, // filled in if state >= PostActTwo
  73                 temp_k2: Option<[u8; 32]>, // filled in if state >= PostActTwo
  74         }
  75 }
  76 enum NoiseState {
  77         InProgress {
  78                 state: NoiseStep,
  79                 directional_state: DirectionalNoiseState,
  80                 bidirectional_state: BidirectionalNoiseState,
  81         },
  82         Finished {
  83                 sk: [u8; 32],
  84                 sn: u64,
  85                 sck: [u8; 32],
  86                 rk: [u8; 32],
  87                 rn: u64,
  88                 rck: [u8; 32],
  89         }
  90 }
  91
  92 pub struct PeerChannelEncryptor {
  93         their_node_id: Option<PublicKey>, // filled in for outbound, or inbound after noise_state is Finished
  94
  95         noise_state: NoiseState,
  96 }
  97
  98 impl PeerChannelEncryptor {
  99         pub fn new_outbound(their_node_id: PublicKey, ephemeral_key: SecretKey) -> PeerChannelEncryptor {
 100                 let mut sha = Sha256::engine();
 101                 sha.input(&NOISE_H);
 102                 sha.input(&their_node_id.serialize()[..]);
 103                 let h = Sha256::from_engine(sha).into_inner();
 104
 105                 PeerChannelEncryptor {
 106                         their_node_id: Some(their_node_id),
 107                         noise_state: NoiseState::InProgress {
 108                                 state: NoiseStep::PreActOne,
 109                                 directional_state: DirectionalNoiseState::Outbound {
 110                                         ie: ephemeral_key,
 111                                 },
 112                                 bidirectional_state: BidirectionalNoiseState {
 113                                         h,
 114                                         ck: NOISE_CK,
 115                                 },
 116                         }
 117                 }
 118         }
 119
 120         pub fn new_inbound<NS: Deref>(node_signer: &NS) -> PeerChannelEncryptor where NS::Target: NodeSigner {
 121                 let mut sha = Sha256::engine();
 122                 sha.input(&NOISE_H);
 123                 let our_node_id = node_signer.get_node_id(Recipient::Node).unwrap();
 124                 sha.input(&our_node_id.serialize()[..]);
 125                 let h = Sha256::from_engine(sha).into_inner();
 126
 127                 PeerChannelEncryptor {
 128                         their_node_id: None,
 129                         noise_state: NoiseState::InProgress {
 130                                 state: NoiseStep::PreActOne,
 131                                 directional_state: DirectionalNoiseState::Inbound {
 132                                         ie: None,
 133                                         re: None,
 134                                         temp_k2: None,
 135                                 },
 136                                 bidirectional_state: BidirectionalNoiseState {
 137                                         h,
 138                                         ck: NOISE_CK,
 139                                 },
 140                         }
 141                 }
 142         }
 143
 144         #[inline]
 145         fn encrypt_with_ad(res: &mut[u8], n: u64, key: &[u8; 32], h: &[u8], plaintext: &[u8]) {
 146                 let mut nonce = [0; 12];
 147                 nonce[4..].copy_from_slice(&n.to_le_bytes()[..]);
 148
 149                 let mut chacha = ChaCha20Poly1305RFC::new(key, &nonce, h);
 150                 let mut tag = [0; 16];
 151                 chacha.encrypt(plaintext, &mut res[0..plaintext.len()], &mut tag);
 152                 res[plaintext.len()..].copy_from_slice(&tag);
 153         }
 154
 155         #[inline]
 156         /// Encrypts the message in res[offset..] in-place and pushes a 16-byte tag onto the end of
 157         /// res.
 158         fn encrypt_in_place_with_ad(res: &mut Vec<u8>, offset: usize, n: u64, key: &[u8; 32], h: &[u8]) {
 159                 let mut nonce = [0; 12];
 160                 nonce[4..].copy_from_slice(&n.to_le_bytes()[..]);
 161
 162                 let mut chacha = ChaCha20Poly1305RFC::new(key, &nonce, h);
 163                 let mut tag = [0; 16];
 164                 chacha.encrypt_full_message_in_place(&mut res[offset..], &mut tag);
 165                 res.extend_from_slice(&tag);
 166         }
 167
 168         #[inline]
 169         fn decrypt_with_ad(res: &mut[u8], n: u64, key: &[u8; 32], h: &[u8], cyphertext: &[u8]) -> Result<(), LightningError> {
 170                 let mut nonce = [0; 12];
 171                 nonce[4..].copy_from_slice(&n.to_le_bytes()[..]);
 172
 173                 let mut chacha = ChaCha20Poly1305RFC::new(key, &nonce, h);
 174                 if !chacha.decrypt(&cyphertext[0..cyphertext.len() - 16], res, &cyphertext[cyphertext.len() - 16..]) {
 175                         return Err(LightningError{err: "Bad MAC".to_owned(), action: msgs::ErrorAction::DisconnectPeer{ msg: None }});
 176                 }
 177                 Ok(())
 178         }
 179
 180         #[inline]
 181         fn hkdf(state: &mut BidirectionalNoiseState, ss: SharedSecret) -> [u8; 32] {
 182                 let (t1, t2) = hkdf_extract_expand_twice(&state.ck, ss.as_ref());
 183                 state.ck = t1;
 184                 t2
 185         }
 186
 187         #[inline]
 188         fn outbound_noise_act<T: secp256k1::Signing>(secp_ctx: &Secp256k1<T>, state: &mut BidirectionalNoiseState, our_key: &SecretKey, their_key: &PublicKey) -> ([u8; 50], [u8; 32]) {
 189                 let our_pub = PublicKey::from_secret_key(secp_ctx, &our_key);
 190
 191                 let mut sha = Sha256::engine();
 192                 sha.input(&state.h);
 193                 sha.input(&our_pub.serialize()[..]);
 194                 state.h = Sha256::from_engine(sha).into_inner();
 195
 196                 let ss = SharedSecret::new(&their_key, &our_key);
 197                 let temp_k = PeerChannelEncryptor::hkdf(state, ss);
 198
 199                 let mut res = [0; 50];
 200                 res[1..34].copy_from_slice(&our_pub.serialize()[..]);
 201                 PeerChannelEncryptor::encrypt_with_ad(&mut res[34..], 0, &temp_k, &state.h, &[0; 0]);
 202
 203                 let mut sha = Sha256::engine();
 204                 sha.input(&state.h);
 205                 sha.input(&res[34..]);
 206                 state.h = Sha256::from_engine(sha).into_inner();
 207
 208                 (res, temp_k)
 209         }
 210
 211         #[inline]
 212         fn inbound_noise_act<'a, 'b, NS: Deref>(
 213                 state: &mut BidirectionalNoiseState, act: &[u8], secret_key: NoiseSecretKey<'a, 'b, NS>
 214         ) -> Result<(PublicKey, [u8; 32]), LightningError> where NS::Target: NodeSigner {
 215                 assert_eq!(act.len(), 50);
 216
 217                 if act[0] != 0 {
 218                         return Err(LightningError{err: format!("Unknown handshake version number {}", act[0]), action: msgs::ErrorAction::DisconnectPeer{ msg: None }});
 219                 }
 220
 221                 let their_pub = match PublicKey::from_slice(&act[1..34]) {
 222                         Err(_) => return Err(LightningError{err: format!("Invalid public key {}", &act[1..34].to_hex()), action: msgs::ErrorAction::DisconnectPeer{ msg: None }}),
 223                         Ok(key) => key,
 224                 };
 225
 226                 let mut sha = Sha256::engine();
 227                 sha.input(&state.h);
 228                 sha.input(&their_pub.serialize()[..]);
 229                 state.h = Sha256::from_engine(sha).into_inner();
 230
 231                 let ss = match secret_key {
 232                         NoiseSecretKey::InMemory(secret_key) => SharedSecret::new(&their_pub, secret_key),
 233                         NoiseSecretKey::NodeSigner(node_signer) => node_signer
 234                                 .ecdh(Recipient::Node, &their_pub, None)
 235                                 .map_err(|_| LightningError {
 236                                         err: "Failed to derive shared secret".to_owned(),
 237                                         action: msgs::ErrorAction::DisconnectPeer { msg: None }
 238                                 })?,
 239                 };
 240                 let temp_k = PeerChannelEncryptor::hkdf(state, ss);
 241
 242                 let mut dec = [0; 0];
 243                 PeerChannelEncryptor::decrypt_with_ad(&mut dec, 0, &temp_k, &state.h, &act[34..])?;
 244
 245                 let mut sha = Sha256::engine();
 246                 sha.input(&state.h);
 247                 sha.input(&act[34..]);
 248                 state.h = Sha256::from_engine(sha).into_inner();
 249
 250                 Ok((their_pub, temp_k))
 251         }
 252
 253         pub fn get_act_one<C: secp256k1::Signing>(&mut self, secp_ctx: &Secp256k1<C>) -> [u8; 50] {
 254                 match self.noise_state {
 255                         NoiseState::InProgress { ref mut state, ref directional_state, ref mut bidirectional_state } =>
 256                                 match directional_state {
 257                                         &DirectionalNoiseState::Outbound { ref ie } => {
 258                                                 if *state != NoiseStep::PreActOne {
 259                                                         panic!("Requested act at wrong step");
 260                                                 }
 261
 262                                                 let (res, _) = PeerChannelEncryptor::outbound_noise_act(secp_ctx, bidirectional_state, &ie, &self.their_node_id.unwrap());
 263                                                 *state = NoiseStep::PostActOne;
 264                                                 res
 265                                         },
 266                                         _ => panic!("Wrong direction for act"),
 267                                 },
 268                         _ => panic!("Cannot get act one after noise handshake completes"),
 269                 }
 270         }
 271
 272         pub fn process_act_one_with_keys<C: secp256k1::Signing, NS: Deref>(
 273                 &mut self, act_one: &[u8], node_signer: &NS, our_ephemeral: SecretKey, secp_ctx: &Secp256k1<C>)
 274         -> Result<[u8; 50], LightningError> where NS::Target: NodeSigner {
 275                 assert_eq!(act_one.len(), 50);
 276
 277                 match self.noise_state {
 278                         NoiseState::InProgress { ref mut state, ref mut directional_state, ref mut bidirectional_state } =>
 279                                 match directional_state {
 280                                         &mut DirectionalNoiseState::Inbound { ref mut ie, ref mut re, ref mut temp_k2 } => {
 281                                                 if *state != NoiseStep::PreActOne {
 282                                                         panic!("Requested act at wrong step");
 283                                                 }
 284
 285                                                 let (their_pub, _) = PeerChannelEncryptor::inbound_noise_act(bidirectional_state, act_one, NoiseSecretKey::NodeSigner(node_signer))?;
 286                                                 ie.get_or_insert(their_pub);
 287
 288                                                 re.get_or_insert(our_ephemeral);
 289
 290                                                 let (res, temp_k) =
 291                                                         PeerChannelEncryptor::outbound_noise_act(secp_ctx, bidirectional_state, &re.unwrap(), &ie.unwrap());
 292                                                 *temp_k2 = Some(temp_k);
 293                                                 *state = NoiseStep::PostActTwo;
 294                                                 Ok(res)
 295                                         },
 296                                         _ => panic!("Wrong direction for act"),
 297                                 },
 298                         _ => panic!("Cannot get act one after noise handshake completes"),
 299                 }
 300         }
 301
 302         pub fn process_act_two<NS: Deref>(
 303                 &mut self, act_two: &[u8], node_signer: &NS)
 304         -> Result<([u8; 66], PublicKey), LightningError> where NS::Target: NodeSigner {
 305                 assert_eq!(act_two.len(), 50);
 306
 307                 let final_hkdf;
 308                 let ck;
 309                 let res: [u8; 66] = match self.noise_state {
 310                         NoiseState::InProgress { ref state, ref directional_state, ref mut bidirectional_state } =>
 311                                 match directional_state {
 312                                         &DirectionalNoiseState::Outbound { ref ie } => {
 313                                                 if *state != NoiseStep::PostActOne {
 314                                                         panic!("Requested act at wrong step");
 315                                                 }
 316
 317                                                 let (re, temp_k2) = PeerChannelEncryptor::inbound_noise_act(bidirectional_state, act_two, NoiseSecretKey::<NS>::InMemory(&ie))?;
 318
 319                                                 let mut res = [0; 66];
 320                                                 let our_node_id = node_signer.get_node_id(Recipient::Node).map_err(|_| LightningError {
 321                                                         err: "Failed to encrypt message".to_owned(),
 322                                                         action: msgs::ErrorAction::DisconnectPeer { msg: None }
 323                                                 })?;
 324
 325                                                 PeerChannelEncryptor::encrypt_with_ad(&mut res[1..50], 1, &temp_k2, &bidirectional_state.h, &our_node_id.serialize()[..]);
 326
 327                                                 let mut sha = Sha256::engine();
 328                                                 sha.input(&bidirectional_state.h);
 329                                                 sha.input(&res[1..50]);
 330                                                 bidirectional_state.h = Sha256::from_engine(sha).into_inner();
 331
 332                                                 let ss = node_signer.ecdh(Recipient::Node, &re, None).map_err(|_| LightningError {
 333                                                         err: "Failed to derive shared secret".to_owned(),
 334                                                         action: msgs::ErrorAction::DisconnectPeer { msg: None }
 335                                                 })?;
 336                                                 let temp_k = PeerChannelEncryptor::hkdf(bidirectional_state, ss);
 337
 338                                                 PeerChannelEncryptor::encrypt_with_ad(&mut res[50..], 0, &temp_k, &bidirectional_state.h, &[0; 0]);
 339                                                 final_hkdf = hkdf_extract_expand_twice(&bidirectional_state.ck, &[0; 0]);
 340                                                 ck = bidirectional_state.ck.clone();
 341                                                 res
 342                                         },
 343                                         _ => panic!("Wrong direction for act"),
 344                                 },
 345                         _ => panic!("Cannot get act one after noise handshake completes"),
 346                 };
 347
 348                 let (sk, rk) = final_hkdf;
 349                 self.noise_state = NoiseState::Finished {
 350                         sk,
 351                         sn: 0,
 352                         sck: ck.clone(),
 353                         rk,
 354                         rn: 0,
 355                         rck: ck,
 356                 };
 357
 358                 Ok((res, self.their_node_id.unwrap().clone()))
 359         }
 360
 361         pub fn process_act_three(&mut self, act_three: &[u8]) -> Result<PublicKey, LightningError> {
 362                 assert_eq!(act_three.len(), 66);
 363
 364                 let final_hkdf;
 365                 let ck;
 366                 match self.noise_state {
 367                         NoiseState::InProgress { ref state, ref directional_state, ref mut bidirectional_state } =>
 368                                 match directional_state {
 369                                         &DirectionalNoiseState::Inbound { ie: _, ref re, ref temp_k2 } => {
 370                                                 if *state != NoiseStep::PostActTwo {
 371                                                         panic!("Requested act at wrong step");
 372                                                 }
 373                                                 if act_three[0] != 0 {
 374                                                         return Err(LightningError{err: format!("Unknown handshake version number {}", act_three[0]), action: msgs::ErrorAction::DisconnectPeer{ msg: None }});
 375                                                 }
 376
 377                                                 let mut their_node_id = [0; 33];
 378                                                 PeerChannelEncryptor::decrypt_with_ad(&mut their_node_id, 1, &temp_k2.unwrap(), &bidirectional_state.h, &act_three[1..50])?;
 379                                                 self.their_node_id = Some(match PublicKey::from_slice(&their_node_id) {
 380                                                         Ok(key) => key,
 381                                                         Err(_) => return Err(LightningError{err: format!("Bad node_id from peer, {}", &their_node_id.to_hex()), action: msgs::ErrorAction::DisconnectPeer{ msg: None }}),
 382                                                 });
 383
 384                                                 let mut sha = Sha256::engine();
 385                                                 sha.input(&bidirectional_state.h);
 386                                                 sha.input(&act_three[1..50]);
 387                                                 bidirectional_state.h = Sha256::from_engine(sha).into_inner();
 388
 389                                                 let ss = SharedSecret::new(&self.their_node_id.unwrap(), &re.unwrap());
 390                                                 let temp_k = PeerChannelEncryptor::hkdf(bidirectional_state, ss);
 391
 392                                                 PeerChannelEncryptor::decrypt_with_ad(&mut [0; 0], 0, &temp_k, &bidirectional_state.h, &act_three[50..])?;
 393                                                 final_hkdf = hkdf_extract_expand_twice(&bidirectional_state.ck, &[0; 0]);
 394                                                 ck = bidirectional_state.ck.clone();
 395                                         },
 396                                         _ => panic!("Wrong direction for act"),
 397                                 },
 398                         _ => panic!("Cannot get act one after noise handshake completes"),
 399                 }
 400
 401                 let (rk, sk) = final_hkdf;
 402                 self.noise_state = NoiseState::Finished {
 403                         sk,
 404                         sn: 0,
 405                         sck: ck.clone(),
 406                         rk,
 407                         rn: 0,
 408                         rck: ck,
 409                 };
 410
 411                 Ok(self.their_node_id.unwrap().clone())
 412         }
 413
 414         /// Encrypts the given pre-serialized message, returning the encrypted version.
 415         /// panics if msg.len() > 65535 or Noise handshake has not finished.
 416         pub fn encrypt_buffer(&mut self, msg: &[u8]) -> Vec<u8> {
 417                 if msg.len() > LN_MAX_MSG_LEN {
 418                         panic!("Attempted to encrypt message longer than 65535 bytes!");
 419                 }
 420
 421                 let mut res = Vec::with_capacity(msg.len() + 16*2 + 2);
 422                 res.resize(msg.len() + 16*2 + 2, 0);
 423
 424                 match self.noise_state {
 425                         NoiseState::Finished { ref mut sk, ref mut sn, ref mut sck, rk: _, rn: _, rck: _ } => {
 426                                 if *sn >= 1000 {
 427                                         let (new_sck, new_sk) = hkdf_extract_expand_twice(sck, sk);
 428                                         *sck = new_sck;
 429                                         *sk = new_sk;
 430                                         *sn = 0;
 431                                 }
 432
 433                                 Self::encrypt_with_ad(&mut res[0..16+2], *sn, sk, &[0; 0], &(msg.len() as u16).to_be_bytes());
 434                                 *sn += 1;
 435
 436                                 Self::encrypt_with_ad(&mut res[16+2..], *sn, sk, &[0; 0], msg);
 437                                 *sn += 1;
 438                         },
 439                         _ => panic!("Tried to encrypt a message prior to noise handshake completion"),
 440                 }
 441
 442                 res
 443         }
 444
 445         /// Encrypts the given message, returning the encrypted version.
 446         /// panics if the length of `message`, once encoded, is greater than 65535 or if the Noise
 447         /// handshake has not finished.
 448         pub fn encrypt_message<M: wire::Type>(&mut self, message: &M) -> Vec<u8> {
 449                 // Allocate a buffer with 2KB, fitting most common messages. Reserve the first 16+2 bytes
 450                 // for the 2-byte message type prefix and its MAC.
 451                 let mut res = VecWriter(Vec::with_capacity(2048));
 452                 res.0.resize(16 + 2, 0);
 453                 wire::write(message, &mut res).expect("In-memory messages must never fail to serialize");
 454
 455                 let msg_len = res.0.len() - 16 - 2;
 456                 if msg_len > LN_MAX_MSG_LEN {
 457                         panic!("Attempted to encrypt message longer than 65535 bytes!");
 458                 }
 459
 460                 match self.noise_state {
 461                         NoiseState::Finished { ref mut sk, ref mut sn, ref mut sck, rk: _, rn: _, rck: _ } => {
 462                                 if *sn >= 1000 {
 463                                         let (new_sck, new_sk) = hkdf_extract_expand_twice(sck, sk);
 464                                         *sck = new_sck;
 465                                         *sk = new_sk;
 466                                         *sn = 0;
 467                                 }
 468
 469                                 Self::encrypt_with_ad(&mut res.0[0..16+2], *sn, sk, &[0; 0], &(msg_len as u16).to_be_bytes());
 470                                 *sn += 1;
 471
 472                                 Self::encrypt_in_place_with_ad(&mut res.0, 16+2, *sn, sk, &[0; 0]);
 473                                 *sn += 1;
 474                         },
 475                         _ => panic!("Tried to encrypt a message prior to noise handshake completion"),
 476                 }
 477
 478                 res.0
 479         }
 480
 481         /// Decrypts a message length header from the remote peer.
 482         /// panics if noise handshake has not yet finished or msg.len() != 18
 483         pub fn decrypt_length_header(&mut self, msg: &[u8]) -> Result<u16, LightningError> {
 484                 assert_eq!(msg.len(), 16+2);
 485
 486                 match self.noise_state {
 487                         NoiseState::Finished { sk: _, sn: _, sck: _, ref mut rk, ref mut rn, ref mut rck } => {
 488                                 if *rn >= 1000 {
 489                                         let (new_rck, new_rk) = hkdf_extract_expand_twice(rck, rk);
 490                                         *rck = new_rck;
 491                                         *rk = new_rk;
 492                                         *rn = 0;
 493                                 }
 494
 495                                 let mut res = [0; 2];
 496                                 Self::decrypt_with_ad(&mut res, *rn, rk, &[0; 0], msg)?;
 497                                 *rn += 1;
 498                                 Ok(u16::from_be_bytes(res))
 499                         },
 500                         _ => panic!("Tried to decrypt a message prior to noise handshake completion"),
 501                 }
 502         }
 503
 504         /// Decrypts the given message.
 505         /// panics if msg.len() > 65535 + 16
 506         pub fn decrypt_message(&mut self, msg: &[u8]) -> Result<Vec<u8>, LightningError> {
 507                 if msg.len() > LN_MAX_MSG_LEN + 16 {
 508                         panic!("Attempted to decrypt message longer than 65535 + 16 bytes!");
 509                 }
 510
 511                 match self.noise_state {
 512                         NoiseState::Finished { sk: _, sn: _, sck: _, ref rk, ref mut rn, rck: _ } => {
 513                                 let mut res = Vec::with_capacity(msg.len() - 16);
 514                                 res.resize(msg.len() - 16, 0);
 515                                 Self::decrypt_with_ad(&mut res[..], *rn, rk, &[0; 0], msg)?;
 516                                 *rn += 1;
 517
 518                                 Ok(res)
 519                         },
 520                         _ => panic!("Tried to decrypt a message prior to noise handshake completion"),
 521                 }
 522         }
 523
 524         pub fn get_noise_step(&self) -> NextNoiseStep {
 525                 match self.noise_state {
 526                         NoiseState::InProgress {ref state, ..} => {
 527                                 match state {
 528                                         &NoiseStep::PreActOne => NextNoiseStep::ActOne,
 529                                         &NoiseStep::PostActOne => NextNoiseStep::ActTwo,
 530                                         &NoiseStep::PostActTwo => NextNoiseStep::ActThree,
 531                                 }
 532                         },
 533                         NoiseState::Finished {..} => NextNoiseStep::NoiseComplete,
 534                 }
 535         }
 536
 537         pub fn is_ready_for_encryption(&self) -> bool {
 538                 match self.noise_state {
 539                         NoiseState::InProgress {..} => { false },
 540                         NoiseState::Finished {..} => { true }
 541                 }
 542         }
 543 }
 544
 545 #[cfg(test)]
 546 mod tests {
 547         use super::LN_MAX_MSG_LEN;
 548
 549         use bitcoin::secp256k1::{PublicKey, SecretKey};
 550         use bitcoin::secp256k1::Secp256k1;
 551
 552         use hex;
 553
 554         use crate::ln::peer_channel_encryptor::{PeerChannelEncryptor,NoiseState};
 555         use crate::util::test_utils::TestNodeSigner;
 556
 557         fn get_outbound_peer_for_initiator_test_vectors() -> PeerChannelEncryptor {
 558                 let their_node_id = PublicKey::from_slice(&hex::decode("028d7500dd4c12685d1f568b4c2b5048e8534b873319f3a8daa612b469132ec7f7").unwrap()[..]).unwrap();
 559                 let secp_ctx = Secp256k1::signing_only();
 560
 561                 let mut outbound_peer = PeerChannelEncryptor::new_outbound(their_node_id, SecretKey::from_slice(&hex::decode("1212121212121212121212121212121212121212121212121212121212121212").unwrap()[..]).unwrap());
 562                 assert_eq!(outbound_peer.get_act_one(&secp_ctx)[..], hex::decode("00036360e856310ce5d294e8be33fc807077dc56ac80d95d9cd4ddbd21325eff73f70df6086551151f58b8afe6c195782c6a").unwrap()[..]);
 563                 outbound_peer
 564         }
 565
 566         fn get_inbound_peer_for_test_vectors() -> PeerChannelEncryptor {
 567                 // transport-responder successful handshake
 568                 let our_node_id = SecretKey::from_slice(&hex::decode("2121212121212121212121212121212121212121212121212121212121212121").unwrap()[..]).unwrap();
 569                 let our_ephemeral = SecretKey::from_slice(&hex::decode("2222222222222222222222222222222222222222222222222222222222222222").unwrap()[..]).unwrap();
 570                 let secp_ctx = Secp256k1::new();
 571                 let node_signer = TestNodeSigner::new(our_node_id);
 572
 573                 let mut inbound_peer = PeerChannelEncryptor::new_inbound(&&node_signer);
 574
 575                 let act_one = hex::decode("00036360e856310ce5d294e8be33fc807077dc56ac80d95d9cd4ddbd21325eff73f70df6086551151f58b8afe6c195782c6a").unwrap().to_vec();
 576                 assert_eq!(inbound_peer.process_act_one_with_keys(&act_one[..], &&node_signer, our_ephemeral.clone(), &secp_ctx).unwrap()[..], hex::decode("0002466d7fcae563e5cb09a0d1870bb580344804617879a14949cf22285f1bae3f276e2470b93aac583c9ef6eafca3f730ae").unwrap()[..]);
 577
 578                 let act_three = hex::decode("00b9e3a702e93e3a9948c2ed6e5fd7590a6e1c3a0344cfc9d5b57357049aa22355361aa02e55a8fc28fef5bd6d71ad0c38228dc68b1c466263b47fdf31e560e139ba").unwrap().to_vec();
 579                 // test vector doesn't specify the initiator static key, but it's the same as the one
 580                 // from transport-initiator successful handshake
 581                 assert_eq!(inbound_peer.process_act_three(&act_three[..]).unwrap().serialize()[..], hex::decode("034f355bdcb7cc0af728ef3cceb9615d90684bb5b2ca5f859ab0f0b704075871aa").unwrap()[..]);
 582
 583                 match inbound_peer.noise_state {
 584                         NoiseState::Finished { sk, sn, sck, rk, rn, rck } => {
 585                                 assert_eq!(sk, hex::decode("bb9020b8965f4df047e07f955f3c4b88418984aadc5cdb35096b9ea8fa5c3442").unwrap()[..]);
 586                                 assert_eq!(sn, 0);
 587                                 assert_eq!(sck, hex::decode("919219dbb2920afa8db80f9a51787a840bcf111ed8d588caf9ab4be716e42b01").unwrap()[..]);
 588                                 assert_eq!(rk, hex::decode("969ab31b4d288cedf6218839b27a3e2140827047f2c0f01bf5c04435d43511a9").unwrap()[..]);
 589                                 assert_eq!(rn, 0);
 590                                 assert_eq!(rck, hex::decode("919219dbb2920afa8db80f9a51787a840bcf111ed8d588caf9ab4be716e42b01").unwrap()[..]);
 591                         },
 592                         _ => panic!()
 593                 }
 594
 595                 inbound_peer
 596         }
 597
 598         #[test]
 599         fn noise_initiator_test_vectors() {
 600                 let our_node_id = SecretKey::from_slice(&hex::decode("1111111111111111111111111111111111111111111111111111111111111111").unwrap()[..]).unwrap();
 601                 let node_signer = TestNodeSigner::new(our_node_id);
 602
 603                 {
 604                         // transport-initiator successful handshake
 605                         let mut outbound_peer = get_outbound_peer_for_initiator_test_vectors();
 606
 607                         let act_two = hex::decode("0002466d7fcae563e5cb09a0d1870bb580344804617879a14949cf22285f1bae3f276e2470b93aac583c9ef6eafca3f730ae").unwrap().to_vec();
 608                         assert_eq!(outbound_peer.process_act_two(&act_two[..], &&node_signer).unwrap().0[..], hex::decode("00b9e3a702e93e3a9948c2ed6e5fd7590a6e1c3a0344cfc9d5b57357049aa22355361aa02e55a8fc28fef5bd6d71ad0c38228dc68b1c466263b47fdf31e560e139ba").unwrap()[..]);
 609
 610                         match outbound_peer.noise_state {
 611                                 NoiseState::Finished { sk, sn, sck, rk, rn, rck } => {
 612                                         assert_eq!(sk, hex::decode("969ab31b4d288cedf6218839b27a3e2140827047f2c0f01bf5c04435d43511a9").unwrap()[..]);
 613                                         assert_eq!(sn, 0);
 614                                         assert_eq!(sck, hex::decode("919219dbb2920afa8db80f9a51787a840bcf111ed8d588caf9ab4be716e42b01").unwrap()[..]);
 615                                         assert_eq!(rk, hex::decode("bb9020b8965f4df047e07f955f3c4b88418984aadc5cdb35096b9ea8fa5c3442").unwrap()[..]);
 616                                         assert_eq!(rn, 0);
 617                                         assert_eq!(rck, hex::decode("919219dbb2920afa8db80f9a51787a840bcf111ed8d588caf9ab4be716e42b01").unwrap()[..]);
 618                                 },
 619                                 _ => panic!()
 620                         }
 621                 }
 622                 {
 623                         // transport-initiator act2 short read test
 624                         // Can't actually test this cause process_act_two requires you pass the right length!
 625                 }
 626                 {
 627                         // transport-initiator act2 bad version test
 628                         let mut outbound_peer = get_outbound_peer_for_initiator_test_vectors();
 629
 630                         let act_two = hex::decode("0102466d7fcae563e5cb09a0d1870bb580344804617879a14949cf22285f1bae3f276e2470b93aac583c9ef6eafca3f730ae").unwrap().to_vec();
 631                         assert!(outbound_peer.process_act_two(&act_two[..], &&node_signer).is_err());
 632                 }
 633
 634                 {
 635                         // transport-initiator act2 bad key serialization test
 636                         let mut outbound_peer = get_outbound_peer_for_initiator_test_vectors();
 637
 638                         let act_two = hex::decode("0004466d7fcae563e5cb09a0d1870bb580344804617879a14949cf22285f1bae3f276e2470b93aac583c9ef6eafca3f730ae").unwrap().to_vec();
 639                         assert!(outbound_peer.process_act_two(&act_two[..], &&node_signer).is_err());
 640                 }
 641
 642                 {
 643                         // transport-initiator act2 bad MAC test
 644                         let mut outbound_peer = get_outbound_peer_for_initiator_test_vectors();
 645
 646                         let act_two = hex::decode("0002466d7fcae563e5cb09a0d1870bb580344804617879a14949cf22285f1bae3f276e2470b93aac583c9ef6eafca3f730af").unwrap().to_vec();
 647                         assert!(outbound_peer.process_act_two(&act_two[..], &&node_signer).is_err());
 648                 }
 649         }
 650
 651         #[test]
 652         fn noise_responder_test_vectors() {
 653                 let our_node_id = SecretKey::from_slice(&hex::decode("2121212121212121212121212121212121212121212121212121212121212121").unwrap()[..]).unwrap();
 654                 let our_ephemeral = SecretKey::from_slice(&hex::decode("2222222222222222222222222222222222222222222222222222222222222222").unwrap()[..]).unwrap();
 655                 let secp_ctx = Secp256k1::new();
 656                 let node_signer = TestNodeSigner::new(our_node_id);
 657
 658                 {
 659                         let _ = get_inbound_peer_for_test_vectors();
 660                 }
 661                 {
 662                         // transport-responder act1 short read test
 663                         // Can't actually test this cause process_act_one requires you pass the right length!
 664                 }
 665                 {
 666                         // transport-responder act1 bad version test
 667                         let mut inbound_peer = PeerChannelEncryptor::new_inbound(&&node_signer);
 668
 669                         let act_one = hex::decode("01036360e856310ce5d294e8be33fc807077dc56ac80d95d9cd4ddbd21325eff73f70df6086551151f58b8afe6c195782c6a").unwrap().to_vec();
 670                         assert!(inbound_peer.process_act_one_with_keys(&act_one[..], &&node_signer, our_ephemeral.clone(), &secp_ctx).is_err());
 671                 }
 672                 {
 673                         // transport-responder act1 bad key serialization test
 674                         let mut inbound_peer = PeerChannelEncryptor::new_inbound(&&node_signer);
 675
 676                         let act_one =hex::decode("00046360e856310ce5d294e8be33fc807077dc56ac80d95d9cd4ddbd21325eff73f70df6086551151f58b8afe6c195782c6a").unwrap().to_vec();
 677                         assert!(inbound_peer.process_act_one_with_keys(&act_one[..], &&node_signer, our_ephemeral.clone(), &secp_ctx).is_err());
 678                 }
 679                 {
 680                         // transport-responder act1 bad MAC test
 681                         let mut inbound_peer = PeerChannelEncryptor::new_inbound(&&node_signer);
 682
 683                         let act_one = hex::decode("00036360e856310ce5d294e8be33fc807077dc56ac80d95d9cd4ddbd21325eff73f70df6086551151f58b8afe6c195782c6b").unwrap().to_vec();
 684                         assert!(inbound_peer.process_act_one_with_keys(&act_one[..], &&node_signer, our_ephemeral.clone(), &secp_ctx).is_err());
 685                 }
 686                 {
 687                         // transport-responder act3 bad version test
 688                         let mut inbound_peer = PeerChannelEncryptor::new_inbound(&&node_signer);
 689
 690                         let act_one = hex::decode("00036360e856310ce5d294e8be33fc807077dc56ac80d95d9cd4ddbd21325eff73f70df6086551151f58b8afe6c195782c6a").unwrap().to_vec();
 691                         assert_eq!(inbound_peer.process_act_one_with_keys(&act_one[..], &&node_signer, our_ephemeral.clone(), &secp_ctx).unwrap()[..], hex::decode("0002466d7fcae563e5cb09a0d1870bb580344804617879a14949cf22285f1bae3f276e2470b93aac583c9ef6eafca3f730ae").unwrap()[..]);
 692
 693                         let act_three = hex::decode("01b9e3a702e93e3a9948c2ed6e5fd7590a6e1c3a0344cfc9d5b57357049aa22355361aa02e55a8fc28fef5bd6d71ad0c38228dc68b1c466263b47fdf31e560e139ba").unwrap().to_vec();
 694                         assert!(inbound_peer.process_act_three(&act_three[..]).is_err());
 695                 }
 696                 {
 697                         // transport-responder act3 short read test
 698                         // Can't actually test this cause process_act_three requires you pass the right length!
 699                 }
 700                 {
 701                         // transport-responder act3 bad MAC for ciphertext test
 702                         let mut inbound_peer = PeerChannelEncryptor::new_inbound(&&node_signer);
 703
 704                         let act_one = hex::decode("00036360e856310ce5d294e8be33fc807077dc56ac80d95d9cd4ddbd21325eff73f70df6086551151f58b8afe6c195782c6a").unwrap().to_vec();
 705                         assert_eq!(inbound_peer.process_act_one_with_keys(&act_one[..], &&node_signer, our_ephemeral.clone(), &secp_ctx).unwrap()[..], hex::decode("0002466d7fcae563e5cb09a0d1870bb580344804617879a14949cf22285f1bae3f276e2470b93aac583c9ef6eafca3f730ae").unwrap()[..]);
 706
 707                         let act_three = hex::decode("00c9e3a702e93e3a9948c2ed6e5fd7590a6e1c3a0344cfc9d5b57357049aa22355361aa02e55a8fc28fef5bd6d71ad0c38228dc68b1c466263b47fdf31e560e139ba").unwrap().to_vec();
 708                         assert!(inbound_peer.process_act_three(&act_three[..]).is_err());
 709                 }
 710                 {
 711                         // transport-responder act3 bad rs test
 712                         let mut inbound_peer = PeerChannelEncryptor::new_inbound(&&node_signer);
 713
 714                         let act_one = hex::decode("00036360e856310ce5d294e8be33fc807077dc56ac80d95d9cd4ddbd21325eff73f70df6086551151f58b8afe6c195782c6a").unwrap().to_vec();
 715                         assert_eq!(inbound_peer.process_act_one_with_keys(&act_one[..], &&node_signer, our_ephemeral.clone(), &secp_ctx).unwrap()[..], hex::decode("0002466d7fcae563e5cb09a0d1870bb580344804617879a14949cf22285f1bae3f276e2470b93aac583c9ef6eafca3f730ae").unwrap()[..]);
 716
 717                         let act_three = hex::decode("00bfe3a702e93e3a9948c2ed6e5fd7590a6e1c3a0344cfc9d5b57357049aa2235536ad09a8ee351870c2bb7f78b754a26c6cef79a98d25139c856d7efd252c2ae73c").unwrap().to_vec();
 718                         assert!(inbound_peer.process_act_three(&act_three[..]).is_err());
 719                 }
 720                 {
 721                         // transport-responder act3 bad MAC test
 722                         let mut inbound_peer = PeerChannelEncryptor::new_inbound(&&node_signer);
 723
 724                         let act_one = hex::decode("00036360e856310ce5d294e8be33fc807077dc56ac80d95d9cd4ddbd21325eff73f70df6086551151f58b8afe6c195782c6a").unwrap().to_vec();
 725                         assert_eq!(inbound_peer.process_act_one_with_keys(&act_one[..], &&node_signer, our_ephemeral.clone(), &secp_ctx).unwrap()[..], hex::decode("0002466d7fcae563e5cb09a0d1870bb580344804617879a14949cf22285f1bae3f276e2470b93aac583c9ef6eafca3f730ae").unwrap()[..]);
 726
 727                         let act_three = hex::decode("00b9e3a702e93e3a9948c2ed6e5fd7590a6e1c3a0344cfc9d5b57357049aa22355361aa02e55a8fc28fef5bd6d71ad0c38228dc68b1c466263b47fdf31e560e139bb").unwrap().to_vec();
 728                         assert!(inbound_peer.process_act_three(&act_three[..]).is_err());
 729                 }
 730         }
 731
 732
 733         #[test]
 734         fn message_encryption_decryption_test_vectors() {
 735                 // We use the same keys as the initiator and responder test vectors, so we copy those tests
 736                 // here and use them to encrypt.
 737                 let mut outbound_peer = get_outbound_peer_for_initiator_test_vectors();
 738
 739                 {
 740                         let our_node_id = SecretKey::from_slice(&hex::decode("1111111111111111111111111111111111111111111111111111111111111111").unwrap()[..]).unwrap();
 741                         let node_signer = TestNodeSigner::new(our_node_id);
 742
 743                         let act_two = hex::decode("0002466d7fcae563e5cb09a0d1870bb580344804617879a14949cf22285f1bae3f276e2470b93aac583c9ef6eafca3f730ae").unwrap().to_vec();
 744                         assert_eq!(outbound_peer.process_act_two(&act_two[..], &&node_signer).unwrap().0[..], hex::decode("00b9e3a702e93e3a9948c2ed6e5fd7590a6e1c3a0344cfc9d5b57357049aa22355361aa02e55a8fc28fef5bd6d71ad0c38228dc68b1c466263b47fdf31e560e139ba").unwrap()[..]);
 745
 746                         match outbound_peer.noise_state {
 747                                 NoiseState::Finished { sk, sn, sck, rk, rn, rck } => {
 748                                         assert_eq!(sk, hex::decode("969ab31b4d288cedf6218839b27a3e2140827047f2c0f01bf5c04435d43511a9").unwrap()[..]);
 749                                         assert_eq!(sn, 0);
 750                                         assert_eq!(sck, hex::decode("919219dbb2920afa8db80f9a51787a840bcf111ed8d588caf9ab4be716e42b01").unwrap()[..]);
 751                                         assert_eq!(rk, hex::decode("bb9020b8965f4df047e07f955f3c4b88418984aadc5cdb35096b9ea8fa5c3442").unwrap()[..]);
 752                                         assert_eq!(rn, 0);
 753                                         assert_eq!(rck, hex::decode("919219dbb2920afa8db80f9a51787a840bcf111ed8d588caf9ab4be716e42b01").unwrap()[..]);
 754                                 },
 755                                 _ => panic!()
 756                         }
 757                 }
 758
 759                 let mut inbound_peer = get_inbound_peer_for_test_vectors();
 760
 761                 for i in 0..1005 {
 762                         let msg = [0x68, 0x65, 0x6c, 0x6c, 0x6f];
 763                         let res = outbound_peer.encrypt_buffer(&msg);
 764                         assert_eq!(res.len(), 5 + 2*16 + 2);
 765
 766                         let len_header = res[0..2+16].to_vec();
 767                         assert_eq!(inbound_peer.decrypt_length_header(&len_header[..]).unwrap() as usize, msg.len());
 768                         assert_eq!(inbound_peer.decrypt_message(&res[2+16..]).unwrap()[..], msg[..]);
 769
 770                         if i == 0 {
 771                                 assert_eq!(res, hex::decode("cf2b30ddf0cf3f80e7c35a6e6730b59fe802473180f396d88a8fb0db8cbcf25d2f214cf9ea1d95").unwrap());
 772                         } else if i == 1 {
 773                                 assert_eq!(res, hex::decode("72887022101f0b6753e0c7de21657d35a4cb2a1f5cde2650528bbc8f837d0f0d7ad833b1a256a1").unwrap());
 774                         } else if i == 500 {
 775                                 assert_eq!(res, hex::decode("178cb9d7387190fa34db9c2d50027d21793c9bc2d40b1e14dcf30ebeeeb220f48364f7a4c68bf8").unwrap());
 776                         } else if i == 501 {
 777                                 assert_eq!(res, hex::decode("1b186c57d44eb6de4c057c49940d79bb838a145cb528d6e8fd26dbe50a60ca2c104b56b60e45bd").unwrap());
 778                         } else if i == 1000 {
 779                                 assert_eq!(res, hex::decode("4a2f3cc3b5e78ddb83dcb426d9863d9d9a723b0337c89dd0b005d89f8d3c05c52b76b29b740f09").unwrap());
 780                         } else if i == 1001 {
 781                                 assert_eq!(res, hex::decode("2ecd8c8a5629d0d02ab457a0fdd0f7b90a192cd46be5ecb6ca570bfc5e268338b1a16cf4ef2d36").unwrap());
 782                         }
 783                 }
 784         }
 785
 786         #[test]
 787         fn max_msg_len_limit_value() {
 788                 assert_eq!(LN_MAX_MSG_LEN, 65535);
 789                 assert_eq!(LN_MAX_MSG_LEN, ::core::u16::MAX as usize);
 790         }
 791
 792         #[test]
 793         #[should_panic(expected = "Attempted to encrypt message longer than 65535 bytes!")]
 794         fn max_message_len_encryption() {
 795                 let mut outbound_peer = get_outbound_peer_for_initiator_test_vectors();
 796                 let msg = [4u8; LN_MAX_MSG_LEN + 1];
 797                 outbound_peer.encrypt_buffer(&msg);
 798         }
 799
 800         #[test]
 801         #[should_panic(expected = "Attempted to decrypt message longer than 65535 + 16 bytes!")]
 802         fn max_message_len_decryption() {
 803                 let mut inbound_peer = get_inbound_peer_for_test_vectors();
 804
 805                 // MSG should not exceed LN_MAX_MSG_LEN + 16
 806                 let msg = [4u8; LN_MAX_MSG_LEN + 17];
 807                 inbound_peer.decrypt_message(&msg).unwrap();
 808         }
 809 }