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[rust-lightning] / lightning / src / util / ser.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 //! A very simple serialization framework which is used to serialize/deserialize messages as well
11 //! as ChannelsManagers and ChannelMonitors.
12
13 use prelude::*;
14 use io::{self, Read, Write};
15 use io_extras::{copy, sink};
16 use core::hash::Hash;
17 use sync::Mutex;
18 use core::cmp;
19
20 use bitcoin::secp256k1::Signature;
21 use bitcoin::secp256k1::key::{PublicKey, SecretKey};
22 use bitcoin::secp256k1::constants::{PUBLIC_KEY_SIZE, SECRET_KEY_SIZE, COMPACT_SIGNATURE_SIZE};
23 use bitcoin::blockdata::script::Script;
24 use bitcoin::blockdata::transaction::{OutPoint, Transaction, TxOut};
25 use bitcoin::consensus;
26 use bitcoin::consensus::Encodable;
27 use bitcoin::hashes::sha256d::Hash as Sha256dHash;
28 use bitcoin::hash_types::{Txid, BlockHash};
29 use core::marker::Sized;
30 use ln::msgs::DecodeError;
31 use ln::{PaymentPreimage, PaymentHash, PaymentSecret};
32
33 use util::byte_utils::{be48_to_array, slice_to_be48};
34
35 /// serialization buffer size
36 pub const MAX_BUF_SIZE: usize = 64 * 1024;
37
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
41 /// hints.
42 ///
43 /// (C-not exported) as we only export serialization to/from byte arrays instead
44 pub trait Writer {
45         /// Writes the given buf out. See std::io::Write::write_all for more
46         fn write_all(&mut self, buf: &[u8]) -> Result<(), 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);
50 }
51
52 impl<W: Write> Writer for W {
53         #[inline]
54         fn write_all(&mut self, buf: &[u8]) -> Result<(), io::Error> {
55                 <Self as io::Write>::write_all(self, buf)
56         }
57         #[inline]
58         fn size_hint(&mut self, _size: usize) { }
59 }
60
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         #[inline]
64         fn write_all(&mut self, buf: &[u8]) -> Result<(), io::Error> {
65                 self.0.write_all(buf)
66         }
67         #[inline]
68         fn write(&mut self, buf: &[u8]) -> Result<usize, io::Error> {
69                 self.0.write_all(buf)?;
70                 Ok(buf.len())
71         }
72         #[inline]
73         fn flush(&mut self) -> Result<(), io::Error> {
74                 Ok(())
75         }
76 }
77
78 pub(crate) struct VecWriter(pub Vec<u8>);
79 impl Writer for VecWriter {
80         #[inline]
81         fn write_all(&mut self, buf: &[u8]) -> Result<(), io::Error> {
82                 self.0.extend_from_slice(buf);
83                 Ok(())
84         }
85         #[inline]
86         fn size_hint(&mut self, size: usize) {
87                 self.0.reserve_exact(size);
88         }
89 }
90
91 /// Writer that only tracks the amount of data written - useful if you need to calculate the length
92 /// of some data when serialized but don't yet need the full data.
93 pub(crate) struct LengthCalculatingWriter(pub usize);
94 impl Writer for LengthCalculatingWriter {
95         #[inline]
96         fn write_all(&mut self, buf: &[u8]) -> Result<(), io::Error> {
97                 self.0 += buf.len();
98                 Ok(())
99         }
100         #[inline]
101         fn size_hint(&mut self, _size: usize) {}
102 }
103
104 /// Essentially std::io::Take but a bit simpler and with a method to walk the underlying stream
105 /// forward to ensure we always consume exactly the fixed length specified.
106 pub(crate) struct FixedLengthReader<R: Read> {
107         read: R,
108         bytes_read: u64,
109         total_bytes: u64,
110 }
111 impl<R: Read> FixedLengthReader<R> {
112         pub fn new(read: R, total_bytes: u64) -> Self {
113                 Self { read, bytes_read: 0, total_bytes }
114         }
115
116         #[inline]
117         pub fn bytes_remain(&mut self) -> bool {
118                 self.bytes_read != self.total_bytes
119         }
120
121         #[inline]
122         pub fn eat_remaining(&mut self) -> Result<(), DecodeError> {
123                 copy(self, &mut sink()).unwrap();
124                 if self.bytes_read != self.total_bytes {
125                         Err(DecodeError::ShortRead)
126                 } else {
127                         Ok(())
128                 }
129         }
130 }
131 impl<R: Read> Read for FixedLengthReader<R> {
132         #[inline]
133         fn read(&mut self, dest: &mut [u8]) -> Result<usize, io::Error> {
134                 if self.total_bytes == self.bytes_read {
135                         Ok(0)
136                 } else {
137                         let read_len = cmp::min(dest.len() as u64, self.total_bytes - self.bytes_read);
138                         match self.read.read(&mut dest[0..(read_len as usize)]) {
139                                 Ok(v) => {
140                                         self.bytes_read += v as u64;
141                                         Ok(v)
142                                 },
143                                 Err(e) => Err(e),
144                         }
145                 }
146         }
147 }
148
149 /// A Read which tracks whether any bytes have been read at all. This allows us to distinguish
150 /// between "EOF reached before we started" and "EOF reached mid-read".
151 pub(crate) struct ReadTrackingReader<R: Read> {
152         read: R,
153         pub have_read: bool,
154 }
155 impl<R: Read> ReadTrackingReader<R> {
156         pub fn new(read: R) -> Self {
157                 Self { read, have_read: false }
158         }
159 }
160 impl<R: Read> Read for ReadTrackingReader<R> {
161         #[inline]
162         fn read(&mut self, dest: &mut [u8]) -> Result<usize, io::Error> {
163                 match self.read.read(dest) {
164                         Ok(0) => Ok(0),
165                         Ok(len) => {
166                                 self.have_read = true;
167                                 Ok(len)
168                         },
169                         Err(e) => Err(e),
170                 }
171         }
172 }
173
174 /// A trait that various rust-lightning types implement allowing them to be written out to a Writer
175 ///
176 /// (C-not exported) as we only export serialization to/from byte arrays instead
177 pub trait Writeable {
178         /// Writes self out to the given Writer
179         fn write<W: Writer>(&self, writer: &mut W) -> Result<(), io::Error>;
180
181         /// Writes self out to a Vec<u8>
182         fn encode(&self) -> Vec<u8> {
183                 let mut msg = VecWriter(Vec::new());
184                 self.write(&mut msg).unwrap();
185                 msg.0
186         }
187
188         /// Writes self out to a Vec<u8>
189         fn encode_with_len(&self) -> Vec<u8> {
190                 let mut msg = VecWriter(Vec::new());
191                 0u16.write(&mut msg).unwrap();
192                 self.write(&mut msg).unwrap();
193                 let len = msg.0.len();
194                 msg.0[..2].copy_from_slice(&(len as u16 - 2).to_be_bytes());
195                 msg.0
196         }
197
198         /// Gets the length of this object after it has been serialized. This can be overridden to
199         /// optimize cases where we prepend an object with its length.
200         // Note that LLVM optimizes this away in most cases! Check that it isn't before you override!
201         #[inline]
202         fn serialized_length(&self) -> usize {
203                 let mut len_calc = LengthCalculatingWriter(0);
204                 self.write(&mut len_calc).expect("No in-memory data may fail to serialize");
205                 len_calc.0
206         }
207 }
208
209 impl<'a, T: Writeable> Writeable for &'a T {
210         fn write<W: Writer>(&self, writer: &mut W) -> Result<(), io::Error> { (*self).write(writer) }
211 }
212
213 /// A trait that various rust-lightning types implement allowing them to be read in from a Read
214 ///
215 /// (C-not exported) as we only export serialization to/from byte arrays instead
216 pub trait Readable
217         where Self: Sized
218 {
219         /// Reads a Self in from the given Read
220         fn read<R: Read>(reader: &mut R) -> Result<Self, DecodeError>;
221 }
222
223 /// A trait that various higher-level rust-lightning types implement allowing them to be read in
224 /// from a Read given some additional set of arguments which is required to deserialize.
225 ///
226 /// (C-not exported) as we only export serialization to/from byte arrays instead
227 pub trait ReadableArgs<P>
228         where Self: Sized
229 {
230         /// Reads a Self in from the given Read
231         fn read<R: Read>(reader: &mut R, params: P) -> Result<Self, DecodeError>;
232 }
233
234 /// A trait that various rust-lightning types implement allowing them to (maybe) be read in from a Read
235 ///
236 /// (C-not exported) as we only export serialization to/from byte arrays instead
237 pub trait MaybeReadable
238         where Self: Sized
239 {
240         /// Reads a Self in from the given Read
241         fn read<R: Read>(reader: &mut R) -> Result<Option<Self>, DecodeError>;
242 }
243
244 impl<T: Readable> MaybeReadable for T {
245         #[inline]
246         fn read<R: Read>(reader: &mut R) -> Result<Option<T>, DecodeError> {
247                 Ok(Some(Readable::read(reader)?))
248         }
249 }
250
251 pub(crate) struct OptionDeserWrapper<T: Readable>(pub Option<T>);
252 impl<T: Readable> Readable for OptionDeserWrapper<T> {
253         #[inline]
254         fn read<R: Read>(reader: &mut R) -> Result<Self, DecodeError> {
255                 Ok(Self(Some(Readable::read(reader)?)))
256         }
257 }
258
259 /// Wrapper to write each element of a Vec with no length prefix
260 pub(crate) struct VecWriteWrapper<'a, T: Writeable>(pub &'a Vec<T>);
261 impl<'a, T: Writeable> Writeable for VecWriteWrapper<'a, T> {
262         #[inline]
263         fn write<W: Writer>(&self, writer: &mut W) -> Result<(), io::Error> {
264                 for ref v in self.0.iter() {
265                         v.write(writer)?;
266                 }
267                 Ok(())
268         }
269 }
270
271 /// Wrapper to read elements from a given stream until it reaches the end of the stream.
272 pub(crate) struct VecReadWrapper<T>(pub Vec<T>);
273 impl<T: MaybeReadable> Readable for VecReadWrapper<T> {
274         #[inline]
275         fn read<R: Read>(mut reader: &mut R) -> Result<Self, DecodeError> {
276                 let mut values = Vec::new();
277                 loop {
278                         let mut track_read = ReadTrackingReader::new(&mut reader);
279                         match MaybeReadable::read(&mut track_read) {
280                                 Ok(Some(v)) => { values.push(v); },
281                                 Ok(None) => { },
282                                 // If we failed to read any bytes at all, we reached the end of our TLV
283                                 // stream and have simply exhausted all entries.
284                                 Err(ref e) if e == &DecodeError::ShortRead && !track_read.have_read => break,
285                                 Err(e) => return Err(e),
286                         }
287                 }
288                 Ok(Self(values))
289         }
290 }
291
292 pub(crate) struct U48(pub u64);
293 impl Writeable for U48 {
294         #[inline]
295         fn write<W: Writer>(&self, writer: &mut W) -> Result<(), io::Error> {
296                 writer.write_all(&be48_to_array(self.0))
297         }
298 }
299 impl Readable for U48 {
300         #[inline]
301         fn read<R: Read>(reader: &mut R) -> Result<U48, DecodeError> {
302                 let mut buf = [0; 6];
303                 reader.read_exact(&mut buf)?;
304                 Ok(U48(slice_to_be48(&buf)))
305         }
306 }
307
308 /// Lightning TLV uses a custom variable-length integer called BigSize. It is similar to Bitcoin's
309 /// variable-length integers except that it is serialized in big-endian instead of little-endian.
310 ///
311 /// Like Bitcoin's variable-length integer, it exhibits ambiguity in that certain values can be
312 /// encoded in several different ways, which we must check for at deserialization-time. Thus, if
313 /// you're looking for an example of a variable-length integer to use for your own project, move
314 /// along, this is a rather poor design.
315 pub(crate) struct BigSize(pub u64);
316 impl Writeable for BigSize {
317         #[inline]
318         fn write<W: Writer>(&self, writer: &mut W) -> Result<(), io::Error> {
319                 match self.0 {
320                         0...0xFC => {
321                                 (self.0 as u8).write(writer)
322                         },
323                         0xFD...0xFFFF => {
324                                 0xFDu8.write(writer)?;
325                                 (self.0 as u16).write(writer)
326                         },
327                         0x10000...0xFFFFFFFF => {
328                                 0xFEu8.write(writer)?;
329                                 (self.0 as u32).write(writer)
330                         },
331                         _ => {
332                                 0xFFu8.write(writer)?;
333                                 (self.0 as u64).write(writer)
334                         },
335                 }
336         }
337 }
338 impl Readable for BigSize {
339         #[inline]
340         fn read<R: Read>(reader: &mut R) -> Result<BigSize, DecodeError> {
341                 let n: u8 = Readable::read(reader)?;
342                 match n {
343                         0xFF => {
344                                 let x: u64 = Readable::read(reader)?;
345                                 if x < 0x100000000 {
346                                         Err(DecodeError::InvalidValue)
347                                 } else {
348                                         Ok(BigSize(x))
349                                 }
350                         }
351                         0xFE => {
352                                 let x: u32 = Readable::read(reader)?;
353                                 if x < 0x10000 {
354                                         Err(DecodeError::InvalidValue)
355                                 } else {
356                                         Ok(BigSize(x as u64))
357                                 }
358                         }
359                         0xFD => {
360                                 let x: u16 = Readable::read(reader)?;
361                                 if x < 0xFD {
362                                         Err(DecodeError::InvalidValue)
363                                 } else {
364                                         Ok(BigSize(x as u64))
365                                 }
366                         }
367                         n => Ok(BigSize(n as u64))
368                 }
369         }
370 }
371
372 /// In TLV we occasionally send fields which only consist of, or potentially end with, a
373 /// variable-length integer which is simply truncated by skipping high zero bytes. This type
374 /// encapsulates such integers implementing Readable/Writeable for them.
375 #[cfg_attr(test, derive(PartialEq, Debug))]
376 pub(crate) struct HighZeroBytesDroppedVarInt<T>(pub T);
377
378 macro_rules! impl_writeable_primitive {
379         ($val_type:ty, $len: expr) => {
380                 impl Writeable for $val_type {
381                         #[inline]
382                         fn write<W: Writer>(&self, writer: &mut W) -> Result<(), io::Error> {
383                                 writer.write_all(&self.to_be_bytes())
384                         }
385                 }
386                 impl Writeable for HighZeroBytesDroppedVarInt<$val_type> {
387                         #[inline]
388                         fn write<W: Writer>(&self, writer: &mut W) -> Result<(), io::Error> {
389                                 // Skip any full leading 0 bytes when writing (in BE):
390                                 writer.write_all(&self.0.to_be_bytes()[(self.0.leading_zeros()/8) as usize..$len])
391                         }
392                 }
393                 impl Readable for $val_type {
394                         #[inline]
395                         fn read<R: Read>(reader: &mut R) -> Result<$val_type, DecodeError> {
396                                 let mut buf = [0; $len];
397                                 reader.read_exact(&mut buf)?;
398                                 Ok(<$val_type>::from_be_bytes(buf))
399                         }
400                 }
401                 impl Readable for HighZeroBytesDroppedVarInt<$val_type> {
402                         #[inline]
403                         fn read<R: Read>(reader: &mut R) -> Result<HighZeroBytesDroppedVarInt<$val_type>, DecodeError> {
404                                 // We need to accept short reads (read_len == 0) as "EOF" and handle them as simply
405                                 // the high bytes being dropped. To do so, we start reading into the middle of buf
406                                 // and then convert the appropriate number of bytes with extra high bytes out of
407                                 // buf.
408                                 let mut buf = [0; $len*2];
409                                 let mut read_len = reader.read(&mut buf[$len..])?;
410                                 let mut total_read_len = read_len;
411                                 while read_len != 0 && total_read_len != $len {
412                                         read_len = reader.read(&mut buf[($len + total_read_len)..])?;
413                                         total_read_len += read_len;
414                                 }
415                                 if total_read_len == 0 || buf[$len] != 0 {
416                                         let first_byte = $len - ($len - total_read_len);
417                                         let mut bytes = [0; $len];
418                                         bytes.copy_from_slice(&buf[first_byte..first_byte + $len]);
419                                         Ok(HighZeroBytesDroppedVarInt(<$val_type>::from_be_bytes(bytes)))
420                                 } else {
421                                         // If the encoding had extra zero bytes, return a failure even though we know
422                                         // what they meant (as the TLV test vectors require this)
423                                         Err(DecodeError::InvalidValue)
424                                 }
425                         }
426                 }
427         }
428 }
429
430 impl_writeable_primitive!(u64, 8);
431 impl_writeable_primitive!(u32, 4);
432 impl_writeable_primitive!(u16, 2);
433
434 impl Writeable for u8 {
435         #[inline]
436         fn write<W: Writer>(&self, writer: &mut W) -> Result<(), io::Error> {
437                 writer.write_all(&[*self])
438         }
439 }
440 impl Readable for u8 {
441         #[inline]
442         fn read<R: Read>(reader: &mut R) -> Result<u8, DecodeError> {
443                 let mut buf = [0; 1];
444                 reader.read_exact(&mut buf)?;
445                 Ok(buf[0])
446         }
447 }
448
449 impl Writeable for bool {
450         #[inline]
451         fn write<W: Writer>(&self, writer: &mut W) -> Result<(), io::Error> {
452                 writer.write_all(&[if *self {1} else {0}])
453         }
454 }
455 impl Readable for bool {
456         #[inline]
457         fn read<R: Read>(reader: &mut R) -> Result<bool, DecodeError> {
458                 let mut buf = [0; 1];
459                 reader.read_exact(&mut buf)?;
460                 if buf[0] != 0 && buf[0] != 1 {
461                         return Err(DecodeError::InvalidValue);
462                 }
463                 Ok(buf[0] == 1)
464         }
465 }
466
467 // u8 arrays
468 macro_rules! impl_array {
469         ( $size:expr ) => (
470                 impl Writeable for [u8; $size]
471                 {
472                         #[inline]
473                         fn write<W: Writer>(&self, w: &mut W) -> Result<(), io::Error> {
474                                 w.write_all(self)
475                         }
476                 }
477
478                 impl Readable for [u8; $size]
479                 {
480                         #[inline]
481                         fn read<R: Read>(r: &mut R) -> Result<Self, DecodeError> {
482                                 let mut buf = [0u8; $size];
483                                 r.read_exact(&mut buf)?;
484                                 Ok(buf)
485                         }
486                 }
487         );
488 }
489
490 //TODO: performance issue with [u8; size] with impl_array!()
491 impl_array!(3); // for rgb
492 impl_array!(4); // for IPv4
493 impl_array!(10); // for OnionV2
494 impl_array!(16); // for IPv6
495 impl_array!(32); // for channel id & hmac
496 impl_array!(PUBLIC_KEY_SIZE); // for PublicKey
497 impl_array!(COMPACT_SIGNATURE_SIZE); // for Signature
498 impl_array!(1300); // for OnionPacket.hop_data
499
500 // HashMap
501 impl<K, V> Writeable for HashMap<K, V>
502         where K: Writeable + Eq + Hash,
503               V: Writeable
504 {
505         #[inline]
506         fn write<W: Writer>(&self, w: &mut W) -> Result<(), io::Error> {
507         (self.len() as u16).write(w)?;
508                 for (key, value) in self.iter() {
509                         key.write(w)?;
510                         value.write(w)?;
511                 }
512                 Ok(())
513         }
514 }
515
516 impl<K, V> Readable for HashMap<K, V>
517         where K: Readable + Eq + Hash,
518               V: Readable
519 {
520         #[inline]
521         fn read<R: Read>(r: &mut R) -> Result<Self, DecodeError> {
522                 let len: u16 = Readable::read(r)?;
523                 let mut ret = HashMap::with_capacity(len as usize);
524                 for _ in 0..len {
525                         ret.insert(K::read(r)?, V::read(r)?);
526                 }
527                 Ok(ret)
528         }
529 }
530
531 // Vectors
532 impl Writeable for Vec<u8> {
533         #[inline]
534         fn write<W: Writer>(&self, w: &mut W) -> Result<(), io::Error> {
535                 (self.len() as u16).write(w)?;
536                 w.write_all(&self)
537         }
538 }
539
540 impl Readable for Vec<u8> {
541         #[inline]
542         fn read<R: Read>(r: &mut R) -> Result<Self, DecodeError> {
543                 let len: u16 = Readable::read(r)?;
544                 let mut ret = Vec::with_capacity(len as usize);
545                 ret.resize(len as usize, 0);
546                 r.read_exact(&mut ret)?;
547                 Ok(ret)
548         }
549 }
550 impl Writeable for Vec<Signature> {
551         #[inline]
552         fn write<W: Writer>(&self, w: &mut W) -> Result<(), io::Error> {
553                 (self.len() as u16).write(w)?;
554                 for e in self.iter() {
555                         e.write(w)?;
556                 }
557                 Ok(())
558         }
559 }
560
561 impl Readable for Vec<Signature> {
562         #[inline]
563         fn read<R: Read>(r: &mut R) -> Result<Self, DecodeError> {
564                 let len: u16 = Readable::read(r)?;
565                 let byte_size = (len as usize)
566                                 .checked_mul(COMPACT_SIGNATURE_SIZE)
567                                 .ok_or(DecodeError::BadLengthDescriptor)?;
568                 if byte_size > MAX_BUF_SIZE {
569                         return Err(DecodeError::BadLengthDescriptor);
570                 }
571                 let mut ret = Vec::with_capacity(len as usize);
572                 for _ in 0..len { ret.push(Readable::read(r)?); }
573                 Ok(ret)
574         }
575 }
576
577 impl Writeable for Script {
578         fn write<W: Writer>(&self, w: &mut W) -> Result<(), io::Error> {
579                 (self.len() as u16).write(w)?;
580                 w.write_all(self.as_bytes())
581         }
582 }
583
584 impl Readable for Script {
585         fn read<R: Read>(r: &mut R) -> Result<Self, DecodeError> {
586                 let len = <u16 as Readable>::read(r)? as usize;
587                 let mut buf = vec![0; len];
588                 r.read_exact(&mut buf)?;
589                 Ok(Script::from(buf))
590         }
591 }
592
593 impl Writeable for PublicKey {
594         fn write<W: Writer>(&self, w: &mut W) -> Result<(), io::Error> {
595                 self.serialize().write(w)
596         }
597         #[inline]
598         fn serialized_length(&self) -> usize {
599                 PUBLIC_KEY_SIZE
600         }
601 }
602
603 impl Readable for PublicKey {
604         fn read<R: Read>(r: &mut R) -> Result<Self, DecodeError> {
605                 let buf: [u8; PUBLIC_KEY_SIZE] = Readable::read(r)?;
606                 match PublicKey::from_slice(&buf) {
607                         Ok(key) => Ok(key),
608                         Err(_) => return Err(DecodeError::InvalidValue),
609                 }
610         }
611 }
612
613 impl Writeable for SecretKey {
614         fn write<W: Writer>(&self, w: &mut W) -> Result<(), io::Error> {
615                 let mut ser = [0; SECRET_KEY_SIZE];
616                 ser.copy_from_slice(&self[..]);
617                 ser.write(w)
618         }
619         #[inline]
620         fn serialized_length(&self) -> usize {
621                 SECRET_KEY_SIZE
622         }
623 }
624
625 impl Readable for SecretKey {
626         fn read<R: Read>(r: &mut R) -> Result<Self, DecodeError> {
627                 let buf: [u8; SECRET_KEY_SIZE] = Readable::read(r)?;
628                 match SecretKey::from_slice(&buf) {
629                         Ok(key) => Ok(key),
630                         Err(_) => return Err(DecodeError::InvalidValue),
631                 }
632         }
633 }
634
635 impl Writeable for Sha256dHash {
636         fn write<W: Writer>(&self, w: &mut W) -> Result<(), io::Error> {
637                 w.write_all(&self[..])
638         }
639 }
640
641 impl Readable for Sha256dHash {
642         fn read<R: Read>(r: &mut R) -> Result<Self, DecodeError> {
643                 use bitcoin::hashes::Hash;
644
645                 let buf: [u8; 32] = Readable::read(r)?;
646                 Ok(Sha256dHash::from_slice(&buf[..]).unwrap())
647         }
648 }
649
650 impl Writeable for Signature {
651         fn write<W: Writer>(&self, w: &mut W) -> Result<(), io::Error> {
652                 self.serialize_compact().write(w)
653         }
654         #[inline]
655         fn serialized_length(&self) -> usize {
656                 COMPACT_SIGNATURE_SIZE
657         }
658 }
659
660 impl Readable for Signature {
661         fn read<R: Read>(r: &mut R) -> Result<Self, DecodeError> {
662                 let buf: [u8; COMPACT_SIGNATURE_SIZE] = Readable::read(r)?;
663                 match Signature::from_compact(&buf) {
664                         Ok(sig) => Ok(sig),
665                         Err(_) => return Err(DecodeError::InvalidValue),
666                 }
667         }
668 }
669
670 impl Writeable for PaymentPreimage {
671         fn write<W: Writer>(&self, w: &mut W) -> Result<(), io::Error> {
672                 self.0.write(w)
673         }
674 }
675
676 impl Readable for PaymentPreimage {
677         fn read<R: Read>(r: &mut R) -> Result<Self, DecodeError> {
678                 let buf: [u8; 32] = Readable::read(r)?;
679                 Ok(PaymentPreimage(buf))
680         }
681 }
682
683 impl Writeable for PaymentHash {
684         fn write<W: Writer>(&self, w: &mut W) -> Result<(), io::Error> {
685                 self.0.write(w)
686         }
687 }
688
689 impl Readable for PaymentHash {
690         fn read<R: Read>(r: &mut R) -> Result<Self, DecodeError> {
691                 let buf: [u8; 32] = Readable::read(r)?;
692                 Ok(PaymentHash(buf))
693         }
694 }
695
696 impl Writeable for PaymentSecret {
697         fn write<W: Writer>(&self, w: &mut W) -> Result<(), io::Error> {
698                 self.0.write(w)
699         }
700 }
701
702 impl Readable for PaymentSecret {
703         fn read<R: Read>(r: &mut R) -> Result<Self, DecodeError> {
704                 let buf: [u8; 32] = Readable::read(r)?;
705                 Ok(PaymentSecret(buf))
706         }
707 }
708
709 impl<T: Writeable> Writeable for Box<T> {
710         fn write<W: Writer>(&self, w: &mut W) -> Result<(), io::Error> {
711                 T::write(&**self, w)
712         }
713 }
714
715 impl<T: Readable> Readable for Box<T> {
716         fn read<R: Read>(r: &mut R) -> Result<Self, DecodeError> {
717                 Ok(Box::new(Readable::read(r)?))
718         }
719 }
720
721 impl<T: Writeable> Writeable for Option<T> {
722         fn write<W: Writer>(&self, w: &mut W) -> Result<(), io::Error> {
723                 match *self {
724                         None => 0u8.write(w)?,
725                         Some(ref data) => {
726                                 BigSize(data.serialized_length() as u64 + 1).write(w)?;
727                                 data.write(w)?;
728                         }
729                 }
730                 Ok(())
731         }
732 }
733
734 impl<T: Readable> Readable for Option<T>
735 {
736         fn read<R: Read>(r: &mut R) -> Result<Self, DecodeError> {
737                 let len: BigSize = Readable::read(r)?;
738                 match len.0 {
739                         0 => Ok(None),
740                         len => {
741                                 let mut reader = FixedLengthReader::new(r, len - 1);
742                                 Ok(Some(Readable::read(&mut reader)?))
743                         }
744                 }
745         }
746 }
747
748 impl Writeable for Txid {
749         fn write<W: Writer>(&self, w: &mut W) -> Result<(), io::Error> {
750                 w.write_all(&self[..])
751         }
752 }
753
754 impl Readable for Txid {
755         fn read<R: Read>(r: &mut R) -> Result<Self, DecodeError> {
756                 use bitcoin::hashes::Hash;
757
758                 let buf: [u8; 32] = Readable::read(r)?;
759                 Ok(Txid::from_slice(&buf[..]).unwrap())
760         }
761 }
762
763 impl Writeable for BlockHash {
764         fn write<W: Writer>(&self, w: &mut W) -> Result<(), io::Error> {
765                 w.write_all(&self[..])
766         }
767 }
768
769 impl Readable for BlockHash {
770         fn read<R: Read>(r: &mut R) -> Result<Self, DecodeError> {
771                 use bitcoin::hashes::Hash;
772
773                 let buf: [u8; 32] = Readable::read(r)?;
774                 Ok(BlockHash::from_slice(&buf[..]).unwrap())
775         }
776 }
777
778 impl Writeable for OutPoint {
779         fn write<W: Writer>(&self, w: &mut W) -> Result<(), io::Error> {
780                 self.txid.write(w)?;
781                 self.vout.write(w)?;
782                 Ok(())
783         }
784 }
785
786 impl Readable for OutPoint {
787         fn read<R: Read>(r: &mut R) -> Result<Self, DecodeError> {
788                 let txid = Readable::read(r)?;
789                 let vout = Readable::read(r)?;
790                 Ok(OutPoint {
791                         txid,
792                         vout,
793                 })
794         }
795 }
796
797 macro_rules! impl_consensus_ser {
798         ($bitcoin_type: ty) => {
799                 impl Writeable for $bitcoin_type {
800                         fn write<W: Writer>(&self, writer: &mut W) -> Result<(), io::Error> {
801                                 match self.consensus_encode(WriterWriteAdaptor(writer)) {
802                                         Ok(_) => Ok(()),
803                                         Err(e) => Err(e),
804                                 }
805                         }
806                 }
807
808                 impl Readable for $bitcoin_type {
809                         fn read<R: Read>(r: &mut R) -> Result<Self, DecodeError> {
810                                 match consensus::encode::Decodable::consensus_decode(r) {
811                                         Ok(t) => Ok(t),
812                                         Err(consensus::encode::Error::Io(ref e)) if e.kind() == io::ErrorKind::UnexpectedEof => Err(DecodeError::ShortRead),
813                                         Err(consensus::encode::Error::Io(e)) => Err(DecodeError::Io(e.kind())),
814                                         Err(_) => Err(DecodeError::InvalidValue),
815                                 }
816                         }
817                 }
818         }
819 }
820 impl_consensus_ser!(Transaction);
821 impl_consensus_ser!(TxOut);
822
823 impl<T: Readable> Readable for Mutex<T> {
824         fn read<R: Read>(r: &mut R) -> Result<Self, DecodeError> {
825                 let t: T = Readable::read(r)?;
826                 Ok(Mutex::new(t))
827         }
828 }
829 impl<T: Writeable> Writeable for Mutex<T> {
830         fn write<W: Writer>(&self, w: &mut W) -> Result<(), io::Error> {
831                 self.lock().unwrap().write(w)
832         }
833 }
834
835 impl<A: Readable, B: Readable> Readable for (A, B) {
836         fn read<R: Read>(r: &mut R) -> Result<Self, DecodeError> {
837                 let a: A = Readable::read(r)?;
838                 let b: B = Readable::read(r)?;
839                 Ok((a, b))
840         }
841 }
842 impl<A: Writeable, B: Writeable> Writeable for (A, B) {
843         fn write<W: Writer>(&self, w: &mut W) -> Result<(), io::Error> {
844                 self.0.write(w)?;
845                 self.1.write(w)
846         }
847 }
848
849 impl<A: Readable, B: Readable, C: Readable> Readable for (A, B, C) {
850         fn read<R: Read>(r: &mut R) -> Result<Self, DecodeError> {
851                 let a: A = Readable::read(r)?;
852                 let b: B = Readable::read(r)?;
853                 let c: C = Readable::read(r)?;
854                 Ok((a, b, c))
855         }
856 }
857 impl<A: Writeable, B: Writeable, C: Writeable> Writeable for (A, B, C) {
858         fn write<W: Writer>(&self, w: &mut W) -> Result<(), io::Error> {
859                 self.0.write(w)?;
860                 self.1.write(w)?;
861                 self.2.write(w)
862         }
863 }