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Merge pull request #1972 from jkczyz/2023-01-bolt12-spec-updates
[rust-lightning] / 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 }