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