1 // This file is Copyright its original authors, visible in version control
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
10 //! A very simple serialization framework which is used to serialize/deserialize messages as well
11 //! as ChannelsManagers and ChannelMonitors.
13 use std::io::{Read, Write};
14 use std::collections::HashMap;
19 use bitcoin::secp256k1::Signature;
20 use bitcoin::secp256k1::key::{PublicKey, SecretKey};
21 use bitcoin::secp256k1::constants::{PUBLIC_KEY_SIZE, COMPACT_SIGNATURE_SIZE};
22 use bitcoin::blockdata::script::Script;
23 use bitcoin::blockdata::transaction::{OutPoint, Transaction, TxOut};
24 use bitcoin::consensus;
25 use bitcoin::consensus::Encodable;
26 use bitcoin::hashes::sha256d::Hash as Sha256dHash;
27 use bitcoin::hash_types::{Txid, BlockHash};
28 use std::marker::Sized;
29 use ln::msgs::DecodeError;
30 use ln::channelmanager::{PaymentPreimage, PaymentHash, PaymentSecret};
33 use util::byte_utils::{be64_to_array, be48_to_array, be32_to_array, be16_to_array, slice_to_be16, slice_to_be32, slice_to_be48, slice_to_be64};
35 /// serialization buffer size
36 pub const MAX_BUF_SIZE: usize = 64 * 1024;
38 /// A trait that is similar to std::io::Write but has one extra function which can be used to size
39 /// buffers being written into.
40 /// An impl is provided for any type that also impls std::io::Write which simply ignores size
43 /// (C-not exported) as we only export serialization to/from byte arrays instead
45 /// Writes the given buf out. See std::io::Write::write_all for more
46 fn write_all(&mut self, buf: &[u8]) -> Result<(), ::std::io::Error>;
47 /// Hints that data of the given size is about the be written. This may not always be called
48 /// prior to data being written and may be safely ignored.
49 fn size_hint(&mut self, size: usize);
52 impl<W: Write> Writer for W {
54 fn write_all(&mut self, buf: &[u8]) -> Result<(), ::std::io::Error> {
55 <Self as ::std::io::Write>::write_all(self, buf)
58 fn size_hint(&mut self, _size: usize) { }
61 pub(crate) struct WriterWriteAdaptor<'a, W: Writer + 'a>(pub &'a mut W);
62 impl<'a, W: Writer + 'a> Write for WriterWriteAdaptor<'a, W> {
63 fn write_all(&mut self, buf: &[u8]) -> Result<(), ::std::io::Error> {
66 fn write(&mut self, buf: &[u8]) -> Result<usize, ::std::io::Error> {
67 self.0.write_all(buf)?;
70 fn flush(&mut self) -> Result<(), ::std::io::Error> {
75 pub(crate) struct VecWriter(pub Vec<u8>);
76 impl Writer for VecWriter {
77 fn write_all(&mut self, buf: &[u8]) -> Result<(), ::std::io::Error> {
78 self.0.extend_from_slice(buf);
81 fn size_hint(&mut self, size: usize) {
82 self.0.reserve_exact(size);
86 /// Writer that only tracks the amount of data written - useful if you need to calculate the length
87 /// of some data when serialized but don't yet need the full data.
88 pub(crate) struct LengthCalculatingWriter(pub usize);
89 impl Writer for LengthCalculatingWriter {
91 fn write_all(&mut self, buf: &[u8]) -> Result<(), ::std::io::Error> {
96 fn size_hint(&mut self, _size: usize) {}
99 /// Essentially std::io::Take but a bit simpler and with a method to walk the underlying stream
100 /// forward to ensure we always consume exactly the fixed length specified.
101 pub(crate) struct FixedLengthReader<R: Read> {
106 impl<R: Read> FixedLengthReader<R> {
107 pub fn new(read: R, total_bytes: u64) -> Self {
108 Self { read, bytes_read: 0, total_bytes }
111 pub fn bytes_remain(&mut self) -> bool {
112 self.bytes_read != self.total_bytes
115 pub fn eat_remaining(&mut self) -> Result<(), DecodeError> {
116 ::std::io::copy(self, &mut ::std::io::sink()).unwrap();
117 if self.bytes_read != self.total_bytes {
118 Err(DecodeError::ShortRead)
124 impl<R: Read> Read for FixedLengthReader<R> {
125 fn read(&mut self, dest: &mut [u8]) -> Result<usize, ::std::io::Error> {
126 if self.total_bytes == self.bytes_read {
129 let read_len = cmp::min(dest.len() as u64, self.total_bytes - self.bytes_read);
130 match self.read.read(&mut dest[0..(read_len as usize)]) {
132 self.bytes_read += v as u64;
141 /// A Read which tracks whether any bytes have been read at all. This allows us to distinguish
142 /// between "EOF reached before we started" and "EOF reached mid-read".
143 pub(crate) struct ReadTrackingReader<R: Read> {
147 impl<R: Read> ReadTrackingReader<R> {
148 pub fn new(read: R) -> Self {
149 Self { read, have_read: false }
152 impl<R: Read> Read for ReadTrackingReader<R> {
153 fn read(&mut self, dest: &mut [u8]) -> Result<usize, ::std::io::Error> {
154 match self.read.read(dest) {
157 self.have_read = true;
165 /// A trait that various rust-lightning types implement allowing them to be written out to a Writer
167 /// (C-not exported) as we only export serialization to/from byte arrays instead
168 pub trait Writeable {
169 /// Writes self out to the given Writer
170 fn write<W: Writer>(&self, writer: &mut W) -> Result<(), ::std::io::Error>;
172 /// Writes self out to a Vec<u8>
173 fn encode(&self) -> Vec<u8> {
174 let mut msg = VecWriter(Vec::new());
175 self.write(&mut msg).unwrap();
179 /// Writes self out to a Vec<u8>
180 fn encode_with_len(&self) -> Vec<u8> {
181 let mut msg = VecWriter(Vec::new());
182 0u16.write(&mut msg).unwrap();
183 self.write(&mut msg).unwrap();
184 let len = msg.0.len();
185 msg.0[..2].copy_from_slice(&byte_utils::be16_to_array(len as u16 - 2));
190 impl<'a, T: Writeable> Writeable for &'a T {
191 fn write<W: Writer>(&self, writer: &mut W) -> Result<(), ::std::io::Error> { (*self).write(writer) }
194 /// A trait that various rust-lightning types implement allowing them to be read in from a Read
196 /// (C-not exported) as we only export serialization to/from byte arrays instead
200 /// Reads a Self in from the given Read
201 fn read<R: Read>(reader: &mut R) -> Result<Self, DecodeError>;
204 /// A trait that various higher-level rust-lightning types implement allowing them to be read in
205 /// from a Read given some additional set of arguments which is required to deserialize.
207 /// (C-not exported) as we only export serialization to/from byte arrays instead
208 pub trait ReadableArgs<P>
211 /// Reads a Self in from the given Read
212 fn read<R: Read>(reader: &mut R, params: P) -> Result<Self, DecodeError>;
215 /// A trait that various rust-lightning types implement allowing them to (maybe) be read in from a Read
217 /// (C-not exported) as we only export serialization to/from byte arrays instead
218 pub trait MaybeReadable
221 /// Reads a Self in from the given Read
222 fn read<R: Read>(reader: &mut R) -> Result<Option<Self>, DecodeError>;
225 pub(crate) struct U48(pub u64);
226 impl Writeable for U48 {
228 fn write<W: Writer>(&self, writer: &mut W) -> Result<(), ::std::io::Error> {
229 writer.write_all(&be48_to_array(self.0))
232 impl Readable for U48 {
234 fn read<R: Read>(reader: &mut R) -> Result<U48, DecodeError> {
235 let mut buf = [0; 6];
236 reader.read_exact(&mut buf)?;
237 Ok(U48(slice_to_be48(&buf)))
241 /// Lightning TLV uses a custom variable-length integer called BigSize. It is similar to Bitcoin's
242 /// variable-length integers except that it is serialized in big-endian instead of little-endian.
244 /// Like Bitcoin's variable-length integer, it exhibits ambiguity in that certain values can be
245 /// encoded in several different ways, which we must check for at deserialization-time. Thus, if
246 /// you're looking for an example of a variable-length integer to use for your own project, move
247 /// along, this is a rather poor design.
248 pub(crate) struct BigSize(pub u64);
249 impl Writeable for BigSize {
251 fn write<W: Writer>(&self, writer: &mut W) -> Result<(), ::std::io::Error> {
254 (self.0 as u8).write(writer)
257 0xFDu8.write(writer)?;
258 (self.0 as u16).write(writer)
260 0x10000...0xFFFFFFFF => {
261 0xFEu8.write(writer)?;
262 (self.0 as u32).write(writer)
265 0xFFu8.write(writer)?;
266 (self.0 as u64).write(writer)
271 impl Readable for BigSize {
273 fn read<R: Read>(reader: &mut R) -> Result<BigSize, DecodeError> {
274 let n: u8 = Readable::read(reader)?;
277 let x: u64 = Readable::read(reader)?;
279 Err(DecodeError::InvalidValue)
285 let x: u32 = Readable::read(reader)?;
287 Err(DecodeError::InvalidValue)
289 Ok(BigSize(x as u64))
293 let x: u16 = Readable::read(reader)?;
295 Err(DecodeError::InvalidValue)
297 Ok(BigSize(x as u64))
300 n => Ok(BigSize(n as u64))
305 /// In TLV we occasionally send fields which only consist of, or potentially end with, a
306 /// variable-length integer which is simply truncated by skipping high zero bytes. This type
307 /// encapsulates such integers implementing Readable/Writeable for them.
308 #[cfg_attr(test, derive(PartialEq, Debug))]
309 pub(crate) struct HighZeroBytesDroppedVarInt<T>(pub T);
311 macro_rules! impl_writeable_primitive {
312 ($val_type:ty, $meth_write:ident, $len: expr, $meth_read:ident) => {
313 impl Writeable for $val_type {
315 fn write<W: Writer>(&self, writer: &mut W) -> Result<(), ::std::io::Error> {
316 writer.write_all(&$meth_write(*self))
319 impl Writeable for HighZeroBytesDroppedVarInt<$val_type> {
321 fn write<W: Writer>(&self, writer: &mut W) -> Result<(), ::std::io::Error> {
322 // Skip any full leading 0 bytes when writing (in BE):
323 writer.write_all(&$meth_write(self.0)[(self.0.leading_zeros()/8) as usize..$len])
326 impl Readable for $val_type {
328 fn read<R: Read>(reader: &mut R) -> Result<$val_type, DecodeError> {
329 let mut buf = [0; $len];
330 reader.read_exact(&mut buf)?;
334 impl Readable for HighZeroBytesDroppedVarInt<$val_type> {
336 fn read<R: Read>(reader: &mut R) -> Result<HighZeroBytesDroppedVarInt<$val_type>, DecodeError> {
337 // We need to accept short reads (read_len == 0) as "EOF" and handle them as simply
338 // the high bytes being dropped. To do so, we start reading into the middle of buf
339 // and then convert the appropriate number of bytes with extra high bytes out of
341 let mut buf = [0; $len*2];
342 let mut read_len = reader.read(&mut buf[$len..])?;
343 let mut total_read_len = read_len;
344 while read_len != 0 && total_read_len != $len {
345 read_len = reader.read(&mut buf[($len + total_read_len)..])?;
346 total_read_len += read_len;
348 if total_read_len == 0 || buf[$len] != 0 {
349 let first_byte = $len - ($len - total_read_len);
350 Ok(HighZeroBytesDroppedVarInt($meth_read(&buf[first_byte..first_byte + $len])))
352 // If the encoding had extra zero bytes, return a failure even though we know
353 // what they meant (as the TLV test vectors require this)
354 Err(DecodeError::InvalidValue)
361 impl_writeable_primitive!(u64, be64_to_array, 8, slice_to_be64);
362 impl_writeable_primitive!(u32, be32_to_array, 4, slice_to_be32);
363 impl_writeable_primitive!(u16, be16_to_array, 2, slice_to_be16);
365 impl Writeable for u8 {
367 fn write<W: Writer>(&self, writer: &mut W) -> Result<(), ::std::io::Error> {
368 writer.write_all(&[*self])
371 impl Readable for u8 {
373 fn read<R: Read>(reader: &mut R) -> Result<u8, DecodeError> {
374 let mut buf = [0; 1];
375 reader.read_exact(&mut buf)?;
380 impl Writeable for bool {
382 fn write<W: Writer>(&self, writer: &mut W) -> Result<(), ::std::io::Error> {
383 writer.write_all(&[if *self {1} else {0}])
386 impl Readable for bool {
388 fn read<R: Read>(reader: &mut R) -> Result<bool, DecodeError> {
389 let mut buf = [0; 1];
390 reader.read_exact(&mut buf)?;
391 if buf[0] != 0 && buf[0] != 1 {
392 return Err(DecodeError::InvalidValue);
399 macro_rules! impl_array {
401 impl Writeable for [u8; $size]
404 fn write<W: Writer>(&self, w: &mut W) -> Result<(), ::std::io::Error> {
409 impl Readable for [u8; $size]
412 fn read<R: Read>(r: &mut R) -> Result<Self, DecodeError> {
413 let mut buf = [0u8; $size];
414 r.read_exact(&mut buf)?;
421 //TODO: performance issue with [u8; size] with impl_array!()
422 impl_array!(3); // for rgb
423 impl_array!(4); // for IPv4
424 impl_array!(10); // for OnionV2
425 impl_array!(16); // for IPv6
426 impl_array!(32); // for channel id & hmac
427 impl_array!(PUBLIC_KEY_SIZE); // for PublicKey
428 impl_array!(COMPACT_SIGNATURE_SIZE); // for Signature
429 impl_array!(1300); // for OnionPacket.hop_data
432 impl<K, V> Writeable for HashMap<K, V>
433 where K: Writeable + Eq + Hash,
437 fn write<W: Writer>(&self, w: &mut W) -> Result<(), ::std::io::Error> {
438 (self.len() as u16).write(w)?;
439 for (key, value) in self.iter() {
447 impl<K, V> Readable for HashMap<K, V>
448 where K: Readable + Eq + Hash,
452 fn read<R: Read>(r: &mut R) -> Result<Self, DecodeError> {
453 let len: u16 = Readable::read(r)?;
454 let mut ret = HashMap::with_capacity(len as usize);
456 ret.insert(K::read(r)?, V::read(r)?);
463 impl Writeable for Vec<u8> {
465 fn write<W: Writer>(&self, w: &mut W) -> Result<(), ::std::io::Error> {
466 (self.len() as u16).write(w)?;
471 impl Readable for Vec<u8> {
473 fn read<R: Read>(r: &mut R) -> Result<Self, DecodeError> {
474 let len: u16 = Readable::read(r)?;
475 let mut ret = Vec::with_capacity(len as usize);
476 ret.resize(len as usize, 0);
477 r.read_exact(&mut ret)?;
481 impl Writeable for Vec<Signature> {
483 fn write<W: Writer>(&self, w: &mut W) -> Result<(), ::std::io::Error> {
484 (self.len() as u16).write(w)?;
485 for e in self.iter() {
492 impl Readable for Vec<Signature> {
494 fn read<R: Read>(r: &mut R) -> Result<Self, DecodeError> {
495 let len: u16 = Readable::read(r)?;
496 let byte_size = (len as usize)
497 .checked_mul(COMPACT_SIGNATURE_SIZE)
498 .ok_or(DecodeError::BadLengthDescriptor)?;
499 if byte_size > MAX_BUF_SIZE {
500 return Err(DecodeError::BadLengthDescriptor);
502 let mut ret = Vec::with_capacity(len as usize);
503 for _ in 0..len { ret.push(Signature::read(r)?); }
508 impl Writeable for Script {
509 fn write<W: Writer>(&self, w: &mut W) -> Result<(), ::std::io::Error> {
510 (self.len() as u16).write(w)?;
511 w.write_all(self.as_bytes())
515 impl Readable for Script {
516 fn read<R: Read>(r: &mut R) -> Result<Self, DecodeError> {
517 let len = <u16 as Readable>::read(r)? as usize;
518 let mut buf = vec![0; len];
519 r.read_exact(&mut buf)?;
520 Ok(Script::from(buf))
524 impl Writeable for PublicKey {
525 fn write<W: Writer>(&self, w: &mut W) -> Result<(), ::std::io::Error> {
526 self.serialize().write(w)
530 impl Readable for PublicKey {
531 fn read<R: Read>(r: &mut R) -> Result<Self, DecodeError> {
532 let buf: [u8; PUBLIC_KEY_SIZE] = Readable::read(r)?;
533 match PublicKey::from_slice(&buf) {
535 Err(_) => return Err(DecodeError::InvalidValue),
540 impl Writeable for SecretKey {
541 fn write<W: Writer>(&self, w: &mut W) -> Result<(), ::std::io::Error> {
542 let mut ser = [0; 32];
543 ser.copy_from_slice(&self[..]);
548 impl Readable for SecretKey {
549 fn read<R: Read>(r: &mut R) -> Result<Self, DecodeError> {
550 let buf: [u8; 32] = Readable::read(r)?;
551 match SecretKey::from_slice(&buf) {
553 Err(_) => return Err(DecodeError::InvalidValue),
558 impl Writeable for Sha256dHash {
559 fn write<W: Writer>(&self, w: &mut W) -> Result<(), ::std::io::Error> {
560 w.write_all(&self[..])
564 impl Readable for Sha256dHash {
565 fn read<R: Read>(r: &mut R) -> Result<Self, DecodeError> {
566 use bitcoin::hashes::Hash;
568 let buf: [u8; 32] = Readable::read(r)?;
569 Ok(Sha256dHash::from_slice(&buf[..]).unwrap())
573 impl Writeable for Signature {
574 fn write<W: Writer>(&self, w: &mut W) -> Result<(), ::std::io::Error> {
575 self.serialize_compact().write(w)
579 impl Readable for Signature {
580 fn read<R: Read>(r: &mut R) -> Result<Self, DecodeError> {
581 let buf: [u8; COMPACT_SIGNATURE_SIZE] = Readable::read(r)?;
582 match Signature::from_compact(&buf) {
584 Err(_) => return Err(DecodeError::InvalidValue),
589 impl Writeable for PaymentPreimage {
590 fn write<W: Writer>(&self, w: &mut W) -> Result<(), ::std::io::Error> {
595 impl Readable for PaymentPreimage {
596 fn read<R: Read>(r: &mut R) -> Result<Self, DecodeError> {
597 let buf: [u8; 32] = Readable::read(r)?;
598 Ok(PaymentPreimage(buf))
602 impl Writeable for PaymentHash {
603 fn write<W: Writer>(&self, w: &mut W) -> Result<(), ::std::io::Error> {
608 impl Readable for PaymentHash {
609 fn read<R: Read>(r: &mut R) -> Result<Self, DecodeError> {
610 let buf: [u8; 32] = Readable::read(r)?;
615 impl Writeable for PaymentSecret {
616 fn write<W: Writer>(&self, w: &mut W) -> Result<(), ::std::io::Error> {
621 impl Readable for PaymentSecret {
622 fn read<R: Read>(r: &mut R) -> Result<Self, DecodeError> {
623 let buf: [u8; 32] = Readable::read(r)?;
624 Ok(PaymentSecret(buf))
628 impl<T: Writeable> Writeable for Option<T> {
629 fn write<W: Writer>(&self, w: &mut W) -> Result<(), ::std::io::Error> {
631 None => 0u8.write(w)?,
633 let mut len_calc = LengthCalculatingWriter(0);
634 data.write(&mut len_calc).expect("No in-memory data may fail to serialize");
635 BigSize(len_calc.0 as u64 + 1).write(w)?;
643 impl<T: Readable> Readable for Option<T>
645 fn read<R: Read>(r: &mut R) -> Result<Self, DecodeError> {
646 match BigSize::read(r)?.0 {
649 let mut reader = FixedLengthReader::new(r, len - 1);
650 Ok(Some(Readable::read(&mut reader)?))
656 impl Writeable for Txid {
657 fn write<W: Writer>(&self, w: &mut W) -> Result<(), ::std::io::Error> {
658 w.write_all(&self[..])
662 impl Readable for Txid {
663 fn read<R: Read>(r: &mut R) -> Result<Self, DecodeError> {
664 use bitcoin::hashes::Hash;
666 let buf: [u8; 32] = Readable::read(r)?;
667 Ok(Txid::from_slice(&buf[..]).unwrap())
671 impl Writeable for BlockHash {
672 fn write<W: Writer>(&self, w: &mut W) -> Result<(), ::std::io::Error> {
673 w.write_all(&self[..])
677 impl Readable for BlockHash {
678 fn read<R: Read>(r: &mut R) -> Result<Self, DecodeError> {
679 use bitcoin::hashes::Hash;
681 let buf: [u8; 32] = Readable::read(r)?;
682 Ok(BlockHash::from_slice(&buf[..]).unwrap())
686 impl Writeable for OutPoint {
687 fn write<W: Writer>(&self, w: &mut W) -> Result<(), ::std::io::Error> {
694 impl Readable for OutPoint {
695 fn read<R: Read>(r: &mut R) -> Result<Self, DecodeError> {
696 let txid = Readable::read(r)?;
697 let vout = Readable::read(r)?;
705 macro_rules! impl_consensus_ser {
706 ($bitcoin_type: ty) => {
707 impl Writeable for $bitcoin_type {
708 fn write<W: Writer>(&self, writer: &mut W) -> Result<(), ::std::io::Error> {
709 match self.consensus_encode(WriterWriteAdaptor(writer)) {
716 impl Readable for $bitcoin_type {
717 fn read<R: Read>(r: &mut R) -> Result<Self, DecodeError> {
718 match consensus::encode::Decodable::consensus_decode(r) {
720 Err(consensus::encode::Error::Io(ref e)) if e.kind() == ::std::io::ErrorKind::UnexpectedEof => Err(DecodeError::ShortRead),
721 Err(consensus::encode::Error::Io(e)) => Err(DecodeError::Io(e.kind())),
722 Err(_) => Err(DecodeError::InvalidValue),
728 impl_consensus_ser!(Transaction);
729 impl_consensus_ser!(TxOut);
731 impl<T: Readable> Readable for Mutex<T> {
732 fn read<R: Read>(r: &mut R) -> Result<Self, DecodeError> {
733 let t: T = Readable::read(r)?;
737 impl<T: Writeable> Writeable for Mutex<T> {
738 fn write<W: Writer>(&self, w: &mut W) -> Result<(), ::std::io::Error> {
739 self.lock().unwrap().write(w)
743 impl<A: Readable, B: Readable> Readable for (A, B) {
744 fn read<R: Read>(r: &mut R) -> Result<Self, DecodeError> {
745 let a: A = Readable::read(r)?;
746 let b: B = Readable::read(r)?;
750 impl<A: Writeable, B: Writeable> Writeable for (A, B) {
751 fn write<W: Writer>(&self, w: &mut W) -> Result<(), ::std::io::Error> {