_ Git - rust-lightning/blob - 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 [`ChannelManager`]s and [`ChannelMonitor`]s.
  12 //!
  13 //! [`ChannelManager`]: crate::ln::channelmanager::ChannelManager
  14 //! [`ChannelMonitor`]: crate::chain::channelmonitor::ChannelMonitor
  15
  16 use crate::prelude::*;
  17 use crate::io::{self, Read, Seek, Write};
  18 use crate::io_extras::{copy, sink};
  19 use core::hash::Hash;
  20 use crate::sync::Mutex;
  21 use core::cmp;
  22 use core::convert::TryFrom;
  23 use core::ops::Deref;
  24
  25 use alloc::collections::BTreeMap;
  26
  27 use bitcoin::secp256k1::{PublicKey, SecretKey};
  28 use bitcoin::secp256k1::constants::{PUBLIC_KEY_SIZE, SECRET_KEY_SIZE, COMPACT_SIGNATURE_SIZE, SCHNORR_SIGNATURE_SIZE};
  29 use bitcoin::secp256k1::ecdsa;
  30 use bitcoin::secp256k1::schnorr;
  31 use bitcoin::blockdata::constants::ChainHash;
  32 use bitcoin::blockdata::script::Script;
  33 use bitcoin::blockdata::transaction::{OutPoint, Transaction, TxOut};
  34 use bitcoin::consensus;
  35 use bitcoin::consensus::Encodable;
  36 use bitcoin::hashes::sha256d::Hash as Sha256dHash;
  37 use bitcoin::hash_types::{Txid, BlockHash};
  38 use core::marker::Sized;
  39 use core::time::Duration;
  40 use crate::ln::msgs::DecodeError;
  41 use crate::ln::{PaymentPreimage, PaymentHash, PaymentSecret};
  42
  43 use crate::util::byte_utils::{be48_to_array, slice_to_be48};
  44
  45 /// serialization buffer size
  46 pub const MAX_BUF_SIZE: usize = 64 * 1024;
  47
  48 /// A simplified version of [`std::io::Write`] that exists largely for backwards compatibility.
  49 /// An impl is provided for any type that also impls [`std::io::Write`].
  50 ///
  51 /// This is not exported to bindings users as we only export serialization to/from byte arrays instead
  52 pub trait Writer {
  53         /// Writes the given buf out. See std::io::Write::write_all for more
  54         fn write_all(&mut self, buf: &[u8]) -> Result<(), io::Error>;
  55 }
  56
  57 impl<W: Write> Writer for W {
  58         #[inline]
  59         fn write_all(&mut self, buf: &[u8]) -> Result<(), io::Error> {
  60                 <Self as io::Write>::write_all(self, buf)
  61         }
  62 }
  63
  64 pub(crate) struct WriterWriteAdaptor<'a, W: Writer + 'a>(pub &'a mut W);
  65 impl<'a, W: Writer + 'a> Write for WriterWriteAdaptor<'a, W> {
  66         #[inline]
  67         fn write_all(&mut self, buf: &[u8]) -> Result<(), io::Error> {
  68                 self.0.write_all(buf)
  69         }
  70         #[inline]
  71         fn write(&mut self, buf: &[u8]) -> Result<usize, io::Error> {
  72                 self.0.write_all(buf)?;
  73                 Ok(buf.len())
  74         }
  75         #[inline]
  76         fn flush(&mut self) -> Result<(), io::Error> {
  77                 Ok(())
  78         }
  79 }
  80
  81 pub(crate) struct VecWriter(pub Vec<u8>);
  82 impl Writer for VecWriter {
  83         #[inline]
  84         fn write_all(&mut self, buf: &[u8]) -> Result<(), io::Error> {
  85                 self.0.extend_from_slice(buf);
  86                 Ok(())
  87         }
  88 }
  89
  90 /// Writer that only tracks the amount of data written - useful if you need to calculate the length
  91 /// of some data when serialized but don't yet need the full data.
  92 ///
  93 /// This is not exported to bindings users as manual TLV building is not currently supported in bindings
  94 pub struct LengthCalculatingWriter(pub usize);
  95 impl Writer for LengthCalculatingWriter {
  96         #[inline]
  97         fn write_all(&mut self, buf: &[u8]) -> Result<(), io::Error> {
  98                 self.0 += buf.len();
  99                 Ok(())
 100         }
 101 }
 102
 103 /// Essentially [`std::io::Take`] but a bit simpler and with a method to walk the underlying stream
 104 /// forward to ensure we always consume exactly the fixed length specified.
 105 ///
 106 /// This is not exported to bindings users as manual TLV building is not currently supported in bindings
 107 pub struct FixedLengthReader<R: Read> {
 108         read: R,
 109         bytes_read: u64,
 110         total_bytes: u64,
 111 }
 112 impl<R: Read> FixedLengthReader<R> {
 113         /// Returns a new [`FixedLengthReader`].
 114         pub fn new(read: R, total_bytes: u64) -> Self {
 115                 Self { read, bytes_read: 0, total_bytes }
 116         }
 117
 118         /// Returns whether some bytes are remaining or not.
 119         #[inline]
 120         pub fn bytes_remain(&mut self) -> bool {
 121                 self.bytes_read != self.total_bytes
 122         }
 123
 124         /// Consumes the remaining bytes.
 125         #[inline]
 126         pub fn eat_remaining(&mut self) -> Result<(), DecodeError> {
 127                 copy(self, &mut sink()).unwrap();
 128                 if self.bytes_read != self.total_bytes {
 129                         Err(DecodeError::ShortRead)
 130                 } else {
 131                         Ok(())
 132                 }
 133         }
 134 }
 135 impl<R: Read> Read for FixedLengthReader<R> {
 136         #[inline]
 137         fn read(&mut self, dest: &mut [u8]) -> Result<usize, io::Error> {
 138                 if self.total_bytes == self.bytes_read {
 139                         Ok(0)
 140                 } else {
 141                         let read_len = cmp::min(dest.len() as u64, self.total_bytes - self.bytes_read);
 142                         match self.read.read(&mut dest[0..(read_len as usize)]) {
 143                                 Ok(v) => {
 144                                         self.bytes_read += v as u64;
 145                                         Ok(v)
 146                                 },
 147                                 Err(e) => Err(e),
 148                         }
 149                 }
 150         }
 151 }
 152
 153 impl<R: Read> LengthRead for FixedLengthReader<R> {
 154         #[inline]
 155         fn total_bytes(&self) -> u64 {
 156                 self.total_bytes
 157         }
 158 }
 159
 160 /// A [`Read`] implementation which tracks whether any bytes have been read at all. This allows us to distinguish
 161 /// between "EOF reached before we started" and "EOF reached mid-read".
 162 ///
 163 /// This is not exported to bindings users as manual TLV building is not currently supported in bindings
 164 pub struct ReadTrackingReader<R: Read> {
 165         read: R,
 166         /// Returns whether we have read from this reader or not yet.
 167         pub have_read: bool,
 168 }
 169 impl<R: Read> ReadTrackingReader<R> {
 170         /// Returns a new [`ReadTrackingReader`].
 171         pub fn new(read: R) -> Self {
 172                 Self { read, have_read: false }
 173         }
 174 }
 175 impl<R: Read> Read for ReadTrackingReader<R> {
 176         #[inline]
 177         fn read(&mut self, dest: &mut [u8]) -> Result<usize, io::Error> {
 178                 match self.read.read(dest) {
 179                         Ok(0) => Ok(0),
 180                         Ok(len) => {
 181                                 self.have_read = true;
 182                                 Ok(len)
 183                         },
 184                         Err(e) => Err(e),
 185                 }
 186         }
 187 }
 188
 189 /// A trait that various LDK types implement allowing them to be written out to a [`Writer`].
 190 ///
 191 /// This is not exported to bindings users as we only export serialization to/from byte arrays instead
 192 pub trait Writeable {
 193         /// Writes `self` out to the given [`Writer`].
 194         fn write<W: Writer>(&self, writer: &mut W) -> Result<(), io::Error>;
 195
 196         /// Writes `self` out to a `Vec<u8>`.
 197         fn encode(&self) -> Vec<u8> {
 198                 let mut msg = VecWriter(Vec::new());
 199                 self.write(&mut msg).unwrap();
 200                 msg.0
 201         }
 202
 203         /// Writes `self` out to a `Vec<u8>`.
 204         #[cfg(test)]
 205         fn encode_with_len(&self) -> Vec<u8> {
 206                 let mut msg = VecWriter(Vec::new());
 207                 0u16.write(&mut msg).unwrap();
 208                 self.write(&mut msg).unwrap();
 209                 let len = msg.0.len();
 210                 msg.0[..2].copy_from_slice(&(len as u16 - 2).to_be_bytes());
 211                 msg.0
 212         }
 213
 214         /// Gets the length of this object after it has been serialized. This can be overridden to
 215         /// optimize cases where we prepend an object with its length.
 216         // Note that LLVM optimizes this away in most cases! Check that it isn't before you override!
 217         #[inline]
 218         fn serialized_length(&self) -> usize {
 219                 let mut len_calc = LengthCalculatingWriter(0);
 220                 self.write(&mut len_calc).expect("No in-memory data may fail to serialize");
 221                 len_calc.0
 222         }
 223 }
 224
 225 impl<'a, T: Writeable> Writeable for &'a T {
 226         fn write<W: Writer>(&self, writer: &mut W) -> Result<(), io::Error> { (*self).write(writer) }
 227 }
 228
 229 /// A trait that various LDK types implement allowing them to be read in from a [`Read`].
 230 ///
 231 /// This is not exported to bindings users as we only export serialization to/from byte arrays instead
 232 pub trait Readable
 233         where Self: Sized
 234 {
 235         /// Reads a `Self` in from the given [`Read`].
 236         fn read<R: Read>(reader: &mut R) -> Result<Self, DecodeError>;
 237 }
 238
 239 /// A trait that various LDK types implement allowing them to be read in from a
 240 /// [`Read`]` + `[`Seek`].
 241 pub(crate) trait SeekReadable where Self: Sized {
 242         /// Reads a `Self` in from the given [`Read`].
 243         fn read<R: Read + Seek>(reader: &mut R) -> Result<Self, DecodeError>;
 244 }
 245
 246 /// A trait that various higher-level LDK types implement allowing them to be read in
 247 /// from a [`Read`] given some additional set of arguments which is required to deserialize.
 248 ///
 249 /// This is not exported to bindings users as we only export serialization to/from byte arrays instead
 250 pub trait ReadableArgs<P>
 251         where Self: Sized
 252 {
 253         /// Reads a `Self` in from the given [`Read`].
 254         fn read<R: Read>(reader: &mut R, params: P) -> Result<Self, DecodeError>;
 255 }
 256
 257 /// A [`std::io::Read`] that also provides the total bytes available to be read.
 258 pub(crate) trait LengthRead: Read {
 259         /// The total number of bytes available to be read.
 260         fn total_bytes(&self) -> u64;
 261 }
 262
 263 /// A trait that various higher-level LDK types implement allowing them to be read in
 264 /// from a Read given some additional set of arguments which is required to deserialize, requiring
 265 /// the implementer to provide the total length of the read.
 266 pub(crate) trait LengthReadableArgs<P> where Self: Sized
 267 {
 268         /// Reads a `Self` in from the given [`LengthRead`].
 269         fn read<R: LengthRead>(reader: &mut R, params: P) -> Result<Self, DecodeError>;
 270 }
 271
 272 /// A trait that various higher-level LDK types implement allowing them to be read in
 273 /// from a [`Read`], requiring the implementer to provide the total length of the read.
 274 pub(crate) trait LengthReadable where Self: Sized
 275 {
 276         /// Reads a `Self` in from the given [`LengthRead`].
 277         fn read<R: LengthRead>(reader: &mut R) -> Result<Self, DecodeError>;
 278 }
 279
 280 /// A trait that various LDK types implement allowing them to (maybe) be read in from a [`Read`].
 281 ///
 282 /// This is not exported to bindings users as we only export serialization to/from byte arrays instead
 283 pub trait MaybeReadable
 284         where Self: Sized
 285 {
 286         /// Reads a `Self` in from the given [`Read`].
 287         fn read<R: Read>(reader: &mut R) -> Result<Option<Self>, DecodeError>;
 288 }
 289
 290 impl<T: Readable> MaybeReadable for T {
 291         #[inline]
 292         fn read<R: Read>(reader: &mut R) -> Result<Option<T>, DecodeError> {
 293                 Ok(Some(Readable::read(reader)?))
 294         }
 295 }
 296
 297 /// Wrapper to read a required (non-optional) TLV record.
 298 ///
 299 /// This is not exported to bindings users as manual TLV building is not currently supported in bindings
 300 pub struct RequiredWrapper<T>(pub Option<T>);
 301 impl<T: Readable> Readable for RequiredWrapper<T> {
 302         #[inline]
 303         fn read<R: Read>(reader: &mut R) -> Result<Self, DecodeError> {
 304                 Ok(Self(Some(Readable::read(reader)?)))
 305         }
 306 }
 307 impl<A, T: ReadableArgs<A>> ReadableArgs<A> for RequiredWrapper<T> {
 308         #[inline]
 309         fn read<R: Read>(reader: &mut R, args: A) -> Result<Self, DecodeError> {
 310                 Ok(Self(Some(ReadableArgs::read(reader, args)?)))
 311         }
 312 }
 313 /// When handling `default_values`, we want to map the default-value T directly
 314 /// to a `RequiredWrapper<T>` in a way that works for `field: T = t;` as
 315 /// well. Thus, we assume `Into<T> for T` does nothing and use that.
 316 impl<T> From<T> for RequiredWrapper<T> {
 317         fn from(t: T) -> RequiredWrapper<T> { RequiredWrapper(Some(t)) }
 318 }
 319
 320 /// Wrapper to read a required (non-optional) TLV record that may have been upgraded without
 321 /// backwards compat.
 322 ///
 323 /// This is not exported to bindings users as manual TLV building is not currently supported in bindings
 324 pub struct UpgradableRequired<T: MaybeReadable>(pub Option<T>);
 325 impl<T: MaybeReadable> MaybeReadable for UpgradableRequired<T> {
 326         #[inline]
 327         fn read<R: Read>(reader: &mut R) -> Result<Option<Self>, DecodeError> {
 328                 let tlv = MaybeReadable::read(reader)?;
 329                 if let Some(tlv) = tlv { return Ok(Some(Self(Some(tlv)))) }
 330                 Ok(None)
 331         }
 332 }
 333
 334 pub(crate) struct U48(pub u64);
 335 impl Writeable for U48 {
 336         #[inline]
 337         fn write<W: Writer>(&self, writer: &mut W) -> Result<(), io::Error> {
 338                 writer.write_all(&be48_to_array(self.0))
 339         }
 340 }
 341 impl Readable for U48 {
 342         #[inline]
 343         fn read<R: Read>(reader: &mut R) -> Result<U48, DecodeError> {
 344                 let mut buf = [0; 6];
 345                 reader.read_exact(&mut buf)?;
 346                 Ok(U48(slice_to_be48(&buf)))
 347         }
 348 }
 349
 350 /// Lightning TLV uses a custom variable-length integer called `BigSize`. It is similar to Bitcoin's
 351 /// variable-length integers except that it is serialized in big-endian instead of little-endian.
 352 ///
 353 /// Like Bitcoin's variable-length integer, it exhibits ambiguity in that certain values can be
 354 /// encoded in several different ways, which we must check for at deserialization-time. Thus, if
 355 /// you're looking for an example of a variable-length integer to use for your own project, move
 356 /// along, this is a rather poor design.
 357 pub struct BigSize(pub u64);
 358 impl Writeable for BigSize {
 359         #[inline]
 360         fn write<W: Writer>(&self, writer: &mut W) -> Result<(), io::Error> {
 361                 match self.0 {
 362                         0...0xFC => {
 363                                 (self.0 as u8).write(writer)
 364                         },
 365                         0xFD...0xFFFF => {
 366                                 0xFDu8.write(writer)?;
 367                                 (self.0 as u16).write(writer)
 368                         },
 369                         0x10000...0xFFFFFFFF => {
 370                                 0xFEu8.write(writer)?;
 371                                 (self.0 as u32).write(writer)
 372                         },
 373                         _ => {
 374                                 0xFFu8.write(writer)?;
 375                                 (self.0 as u64).write(writer)
 376                         },
 377                 }
 378         }
 379 }
 380 impl Readable for BigSize {
 381         #[inline]
 382         fn read<R: Read>(reader: &mut R) -> Result<BigSize, DecodeError> {
 383                 let n: u8 = Readable::read(reader)?;
 384                 match n {
 385                         0xFF => {
 386                                 let x: u64 = Readable::read(reader)?;
 387                                 if x < 0x100000000 {
 388                                         Err(DecodeError::InvalidValue)
 389                                 } else {
 390                                         Ok(BigSize(x))
 391                                 }
 392                         }
 393                         0xFE => {
 394                                 let x: u32 = Readable::read(reader)?;
 395                                 if x < 0x10000 {
 396                                         Err(DecodeError::InvalidValue)
 397                                 } else {
 398                                         Ok(BigSize(x as u64))
 399                                 }
 400                         }
 401                         0xFD => {
 402                                 let x: u16 = Readable::read(reader)?;
 403                                 if x < 0xFD {
 404                                         Err(DecodeError::InvalidValue)
 405                                 } else {
 406                                         Ok(BigSize(x as u64))
 407                                 }
 408                         }
 409                         n => Ok(BigSize(n as u64))
 410                 }
 411         }
 412 }
 413
 414 /// The lightning protocol uses u16s for lengths in most cases. As our serialization framework
 415 /// primarily targets that, we must as well. However, because we may serialize objects that have
 416 /// more than 65K entries, we need to be able to store larger values. Thus, we define a variable
 417 /// length integer here that is backwards-compatible for values < 0xffff. We treat 0xffff as
 418 /// "read eight more bytes".
 419 ///
 420 /// To ensure we only have one valid encoding per value, we add 0xffff to values written as eight
 421 /// bytes. Thus, 0xfffe is serialized as 0xfffe, whereas 0xffff is serialized as
 422 /// 0xffff0000000000000000 (i.e. read-eight-bytes then zero).
 423 struct CollectionLength(pub u64);
 424 impl Writeable for CollectionLength {
 425         #[inline]
 426         fn write<W: Writer>(&self, writer: &mut W) -> Result<(), io::Error> {
 427                 if self.0 < 0xffff {
 428                         (self.0 as u16).write(writer)
 429                 } else {
 430                         0xffffu16.write(writer)?;
 431                         (self.0 - 0xffff).write(writer)
 432                 }
 433         }
 434 }
 435
 436 impl Readable for CollectionLength {
 437         #[inline]
 438         fn read<R: Read>(r: &mut R) -> Result<Self, DecodeError> {
 439                 let mut val: u64 = <u16 as Readable>::read(r)? as u64;
 440                 if val == 0xffff {
 441                         val = <u64 as Readable>::read(r)?
 442                                 .checked_add(0xffff).ok_or(DecodeError::InvalidValue)?;
 443                 }
 444                 Ok(CollectionLength(val))
 445         }
 446 }
 447
 448 /// In TLV we occasionally send fields which only consist of, or potentially end with, a
 449 /// variable-length integer which is simply truncated by skipping high zero bytes. This type
 450 /// encapsulates such integers implementing [`Readable`]/[`Writeable`] for them.
 451 #[cfg_attr(test, derive(PartialEq, Eq, Debug))]
 452 pub(crate) struct HighZeroBytesDroppedBigSize<T>(pub T);
 453
 454 macro_rules! impl_writeable_primitive {
 455         ($val_type:ty, $len: expr) => {
 456                 impl Writeable for $val_type {
 457                         #[inline]
 458                         fn write<W: Writer>(&self, writer: &mut W) -> Result<(), io::Error> {
 459                                 writer.write_all(&self.to_be_bytes())
 460                         }
 461                 }
 462                 impl Writeable for HighZeroBytesDroppedBigSize<$val_type> {
 463                         #[inline]
 464                         fn write<W: Writer>(&self, writer: &mut W) -> Result<(), io::Error> {
 465                                 // Skip any full leading 0 bytes when writing (in BE):
 466                                 writer.write_all(&self.0.to_be_bytes()[(self.0.leading_zeros()/8) as usize..$len])
 467                         }
 468                 }
 469                 impl Readable for $val_type {
 470                         #[inline]
 471                         fn read<R: Read>(reader: &mut R) -> Result<$val_type, DecodeError> {
 472                                 let mut buf = [0; $len];
 473                                 reader.read_exact(&mut buf)?;
 474                                 Ok(<$val_type>::from_be_bytes(buf))
 475                         }
 476                 }
 477                 impl Readable for HighZeroBytesDroppedBigSize<$val_type> {
 478                         #[inline]
 479                         fn read<R: Read>(reader: &mut R) -> Result<HighZeroBytesDroppedBigSize<$val_type>, DecodeError> {
 480                                 // We need to accept short reads (read_len == 0) as "EOF" and handle them as simply
 481                                 // the high bytes being dropped. To do so, we start reading into the middle of buf
 482                                 // and then convert the appropriate number of bytes with extra high bytes out of
 483                                 // buf.
 484                                 let mut buf = [0; $len*2];
 485                                 let mut read_len = reader.read(&mut buf[$len..])?;
 486                                 let mut total_read_len = read_len;
 487                                 while read_len != 0 && total_read_len != $len {
 488                                         read_len = reader.read(&mut buf[($len + total_read_len)..])?;
 489                                         total_read_len += read_len;
 490                                 }
 491                                 if total_read_len == 0 || buf[$len] != 0 {
 492                                         let first_byte = $len - ($len - total_read_len);
 493                                         let mut bytes = [0; $len];
 494                                         bytes.copy_from_slice(&buf[first_byte..first_byte + $len]);
 495                                         Ok(HighZeroBytesDroppedBigSize(<$val_type>::from_be_bytes(bytes)))
 496                                 } else {
 497                                         // If the encoding had extra zero bytes, return a failure even though we know
 498                                         // what they meant (as the TLV test vectors require this)
 499                                         Err(DecodeError::InvalidValue)
 500                                 }
 501                         }
 502                 }
 503                 impl From<$val_type> for HighZeroBytesDroppedBigSize<$val_type> {
 504                         fn from(val: $val_type) -> Self { Self(val) }
 505                 }
 506         }
 507 }
 508
 509 impl_writeable_primitive!(u128, 16);
 510 impl_writeable_primitive!(u64, 8);
 511 impl_writeable_primitive!(u32, 4);
 512 impl_writeable_primitive!(u16, 2);
 513
 514 impl Writeable for u8 {
 515         #[inline]
 516         fn write<W: Writer>(&self, writer: &mut W) -> Result<(), io::Error> {
 517                 writer.write_all(&[*self])
 518         }
 519 }
 520 impl Readable for u8 {
 521         #[inline]
 522         fn read<R: Read>(reader: &mut R) -> Result<u8, DecodeError> {
 523                 let mut buf = [0; 1];
 524                 reader.read_exact(&mut buf)?;
 525                 Ok(buf[0])
 526         }
 527 }
 528
 529 impl Writeable for bool {
 530         #[inline]
 531         fn write<W: Writer>(&self, writer: &mut W) -> Result<(), io::Error> {
 532                 writer.write_all(&[if *self {1} else {0}])
 533         }
 534 }
 535 impl Readable for bool {
 536         #[inline]
 537         fn read<R: Read>(reader: &mut R) -> Result<bool, DecodeError> {
 538                 let mut buf = [0; 1];
 539                 reader.read_exact(&mut buf)?;
 540                 if buf[0] != 0 && buf[0] != 1 {
 541                         return Err(DecodeError::InvalidValue);
 542                 }
 543                 Ok(buf[0] == 1)
 544         }
 545 }
 546
 547 // u8 arrays
 548 macro_rules! impl_array {
 549         ( $size:expr ) => (
 550                 impl Writeable for [u8; $size]
 551                 {
 552                         #[inline]
 553                         fn write<W: Writer>(&self, w: &mut W) -> Result<(), io::Error> {
 554                                 w.write_all(self)
 555                         }
 556                 }
 557
 558                 impl Readable for [u8; $size]
 559                 {
 560                         #[inline]
 561                         fn read<R: Read>(r: &mut R) -> Result<Self, DecodeError> {
 562                                 let mut buf = [0u8; $size];
 563                                 r.read_exact(&mut buf)?;
 564                                 Ok(buf)
 565                         }
 566                 }
 567         );
 568 }
 569
 570 impl_array!(3); // for rgb, ISO 4712 code
 571 impl_array!(4); // for IPv4
 572 impl_array!(12); // for OnionV2
 573 impl_array!(16); // for IPv6
 574 impl_array!(32); // for channel id & hmac
 575 impl_array!(PUBLIC_KEY_SIZE); // for PublicKey
 576 impl_array!(64); // for ecdsa::Signature and schnorr::Signature
 577 impl_array!(1300); // for OnionPacket.hop_data
 578
 579 impl Writeable for [u16; 8] {
 580         #[inline]
 581         fn write<W: Writer>(&self, w: &mut W) -> Result<(), io::Error> {
 582                 for v in self.iter() {
 583                         w.write_all(&v.to_be_bytes())?
 584                 }
 585                 Ok(())
 586         }
 587 }
 588
 589 impl Readable for [u16; 8] {
 590         #[inline]
 591         fn read<R: Read>(r: &mut R) -> Result<Self, DecodeError> {
 592                 let mut buf = [0u8; 16];
 593                 r.read_exact(&mut buf)?;
 594                 let mut res = [0u16; 8];
 595                 for (idx, v) in res.iter_mut().enumerate() {
 596                         *v = (buf[idx] as u16) << 8 | (buf[idx + 1] as u16)
 597                 }
 598                 Ok(res)
 599         }
 600 }
 601
 602 /// A type for variable-length values within TLV record where the length is encoded as part of the record.
 603 /// Used to prevent encoding the length twice.
 604 ///
 605 /// This is not exported to bindings users as manual TLV building is not currently supported in bindings
 606 pub struct WithoutLength<T>(pub T);
 607
 608 impl Writeable for WithoutLength<&String> {
 609         #[inline]
 610         fn write<W: Writer>(&self, w: &mut W) -> Result<(), io::Error> {
 611                 w.write_all(self.0.as_bytes())
 612         }
 613 }
 614 impl Readable for WithoutLength<String> {
 615         #[inline]
 616         fn read<R: Read>(r: &mut R) -> Result<Self, DecodeError> {
 617                 let v: WithoutLength<Vec<u8>> = Readable::read(r)?;
 618                 Ok(Self(String::from_utf8(v.0).map_err(|_| DecodeError::InvalidValue)?))
 619         }
 620 }
 621 impl<'a> From<&'a String> for WithoutLength<&'a String> {
 622         fn from(s: &'a String) -> Self { Self(s) }
 623 }
 624
 625 impl<'a, T: Writeable> Writeable for WithoutLength<&'a Vec<T>> {
 626         #[inline]
 627         fn write<W: Writer>(&self, writer: &mut W) -> Result<(), io::Error> {
 628                 for ref v in self.0.iter() {
 629                         v.write(writer)?;
 630                 }
 631                 Ok(())
 632         }
 633 }
 634
 635 impl<T: MaybeReadable> Readable for WithoutLength<Vec<T>> {
 636         #[inline]
 637         fn read<R: Read>(mut reader: &mut R) -> Result<Self, DecodeError> {
 638                 let mut values = Vec::new();
 639                 loop {
 640                         let mut track_read = ReadTrackingReader::new(&mut reader);
 641                         match MaybeReadable::read(&mut track_read) {
 642                                 Ok(Some(v)) => { values.push(v); },
 643                                 Ok(None) => { },
 644                                 // If we failed to read any bytes at all, we reached the end of our TLV
 645                                 // stream and have simply exhausted all entries.
 646                                 Err(ref e) if e == &DecodeError::ShortRead && !track_read.have_read => break,
 647                                 Err(e) => return Err(e),
 648                         }
 649                 }
 650                 Ok(Self(values))
 651         }
 652 }
 653 impl<'a, T> From<&'a Vec<T>> for WithoutLength<&'a Vec<T>> {
 654         fn from(v: &'a Vec<T>) -> Self { Self(v) }
 655 }
 656
 657 #[derive(Debug)]
 658 pub(crate) struct Iterable<'a, I: Iterator<Item = &'a T> + Clone, T: 'a>(pub I);
 659
 660 impl<'a, I: Iterator<Item = &'a T> + Clone, T: 'a + Writeable> Writeable for Iterable<'a, I, T> {
 661         #[inline]
 662         fn write<W: Writer>(&self, writer: &mut W) -> Result<(), io::Error> {
 663                 for ref v in self.0.clone() {
 664                         v.write(writer)?;
 665                 }
 666                 Ok(())
 667         }
 668 }
 669
 670 #[cfg(test)]
 671 impl<'a, I: Iterator<Item = &'a T> + Clone, T: 'a + PartialEq> PartialEq for Iterable<'a, I, T> {
 672         fn eq(&self, other: &Self) -> bool {
 673                 self.0.clone().collect::<Vec<_>>() == other.0.clone().collect::<Vec<_>>()
 674         }
 675 }
 676
 677 macro_rules! impl_for_map {
 678         ($ty: ident, $keybound: ident, $constr: expr) => {
 679                 impl<K, V> Writeable for $ty<K, V>
 680                         where K: Writeable + Eq + $keybound, V: Writeable
 681                 {
 682                         #[inline]
 683                         fn write<W: Writer>(&self, w: &mut W) -> Result<(), io::Error> {
 684                                 CollectionLength(self.len() as u64).write(w)?;
 685                                 for (key, value) in self.iter() {
 686                                         key.write(w)?;
 687                                         value.write(w)?;
 688                                 }
 689                                 Ok(())
 690                         }
 691                 }
 692
 693                 impl<K, V> Readable for $ty<K, V>
 694                         where K: Readable + Eq + $keybound, V: MaybeReadable
 695                 {
 696                         #[inline]
 697                         fn read<R: Read>(r: &mut R) -> Result<Self, DecodeError> {
 698                                 let len: CollectionLength = Readable::read(r)?;
 699                                 let mut ret = $constr(len.0 as usize);
 700                                 for _ in 0..len.0 {
 701                                         let k = K::read(r)?;
 702                                         let v_opt = V::read(r)?;
 703                                         if let Some(v) = v_opt {
 704                                                 if ret.insert(k, v).is_some() {
 705                                                         return Err(DecodeError::InvalidValue);
 706                                                 }
 707                                         }
 708                                 }
 709                                 Ok(ret)
 710                         }
 711                 }
 712         }
 713 }
 714
 715 impl_for_map!(BTreeMap, Ord, |_| BTreeMap::new());
 716 impl_for_map!(HashMap, Hash, |len| HashMap::with_capacity(len));
 717
 718 // HashSet
 719 impl<T> Writeable for HashSet<T>
 720 where T: Writeable + Eq + Hash
 721 {
 722         #[inline]
 723         fn write<W: Writer>(&self, w: &mut W) -> Result<(), io::Error> {
 724                 CollectionLength(self.len() as u64).write(w)?;
 725                 for item in self.iter() {
 726                         item.write(w)?;
 727                 }
 728                 Ok(())
 729         }
 730 }
 731
 732 impl<T> Readable for HashSet<T>
 733 where T: Readable + Eq + Hash
 734 {
 735         #[inline]
 736         fn read<R: Read>(r: &mut R) -> Result<Self, DecodeError> {
 737                 let len: CollectionLength = Readable::read(r)?;
 738                 let mut ret = HashSet::with_capacity(cmp::min(len.0 as usize, MAX_BUF_SIZE / core::mem::size_of::<T>()));
 739                 for _ in 0..len.0 {
 740                         if !ret.insert(T::read(r)?) {
 741                                 return Err(DecodeError::InvalidValue)
 742                         }
 743                 }
 744                 Ok(ret)
 745         }
 746 }
 747
 748 // Vectors
 749 macro_rules! impl_for_vec {
 750         ($ty: ty $(, $name: ident)*) => {
 751                 impl<$($name : Writeable),*> Writeable for Vec<$ty> {
 752                         #[inline]
 753                         fn write<W: Writer>(&self, w: &mut W) -> Result<(), io::Error> {
 754                                 CollectionLength(self.len() as u64).write(w)?;
 755                                 for elem in self.iter() {
 756                                         elem.write(w)?;
 757                                 }
 758                                 Ok(())
 759                         }
 760                 }
 761
 762                 impl<$($name : Readable),*> Readable for Vec<$ty> {
 763                         #[inline]
 764                         fn read<R: Read>(r: &mut R) -> Result<Self, DecodeError> {
 765                                 let len: CollectionLength = Readable::read(r)?;
 766                                 let mut ret = Vec::with_capacity(cmp::min(len.0 as usize, MAX_BUF_SIZE / core::mem::size_of::<$ty>()));
 767                                 for _ in 0..len.0 {
 768                                         if let Some(val) = MaybeReadable::read(r)? {
 769                                                 ret.push(val);
 770                                         }
 771                                 }
 772                                 Ok(ret)
 773                         }
 774                 }
 775         }
 776 }
 777
 778 impl Writeable for Vec<u8> {
 779         #[inline]
 780         fn write<W: Writer>(&self, w: &mut W) -> Result<(), io::Error> {
 781                 CollectionLength(self.len() as u64).write(w)?;
 782                 w.write_all(&self)
 783         }
 784 }
 785
 786 impl Readable for Vec<u8> {
 787         #[inline]
 788         fn read<R: Read>(r: &mut R) -> Result<Self, DecodeError> {
 789                 let mut len: CollectionLength = Readable::read(r)?;
 790                 let mut ret = Vec::new();
 791                 while len.0 > 0 {
 792                         let readamt = cmp::min(len.0 as usize, MAX_BUF_SIZE);
 793                         let readstart = ret.len();
 794                         ret.resize(readstart + readamt, 0);
 795                         r.read_exact(&mut ret[readstart..])?;
 796                         len.0 -= readamt as u64;
 797                 }
 798                 Ok(ret)
 799         }
 800 }
 801
 802 impl_for_vec!(ecdsa::Signature);
 803 impl_for_vec!(crate::ln::channelmanager::MonitorUpdateCompletionAction);
 804 impl_for_vec!((A, B), A, B);
 805
 806 impl Writeable for Script {
 807         fn write<W: Writer>(&self, w: &mut W) -> Result<(), io::Error> {
 808                 (self.len() as u16).write(w)?;
 809                 w.write_all(self.as_bytes())
 810         }
 811 }
 812
 813 impl Readable for Script {
 814         fn read<R: Read>(r: &mut R) -> Result<Self, DecodeError> {
 815                 let len = <u16 as Readable>::read(r)? as usize;
 816                 let mut buf = vec![0; len];
 817                 r.read_exact(&mut buf)?;
 818                 Ok(Script::from(buf))
 819         }
 820 }
 821
 822 impl Writeable for PublicKey {
 823         fn write<W: Writer>(&self, w: &mut W) -> Result<(), io::Error> {
 824                 self.serialize().write(w)
 825         }
 826         #[inline]
 827         fn serialized_length(&self) -> usize {
 828                 PUBLIC_KEY_SIZE
 829         }
 830 }
 831
 832 impl Readable for PublicKey {
 833         fn read<R: Read>(r: &mut R) -> Result<Self, DecodeError> {
 834                 let buf: [u8; PUBLIC_KEY_SIZE] = Readable::read(r)?;
 835                 match PublicKey::from_slice(&buf) {
 836                         Ok(key) => Ok(key),
 837                         Err(_) => return Err(DecodeError::InvalidValue),
 838                 }
 839         }
 840 }
 841
 842 impl Writeable for SecretKey {
 843         fn write<W: Writer>(&self, w: &mut W) -> Result<(), io::Error> {
 844                 let mut ser = [0; SECRET_KEY_SIZE];
 845                 ser.copy_from_slice(&self[..]);
 846                 ser.write(w)
 847         }
 848         #[inline]
 849         fn serialized_length(&self) -> usize {
 850                 SECRET_KEY_SIZE
 851         }
 852 }
 853
 854 impl Readable for SecretKey {
 855         fn read<R: Read>(r: &mut R) -> Result<Self, DecodeError> {
 856                 let buf: [u8; SECRET_KEY_SIZE] = Readable::read(r)?;
 857                 match SecretKey::from_slice(&buf) {
 858                         Ok(key) => Ok(key),
 859                         Err(_) => return Err(DecodeError::InvalidValue),
 860                 }
 861         }
 862 }
 863
 864 impl Writeable for Sha256dHash {
 865         fn write<W: Writer>(&self, w: &mut W) -> Result<(), io::Error> {
 866                 w.write_all(&self[..])
 867         }
 868 }
 869
 870 impl Readable for Sha256dHash {
 871         fn read<R: Read>(r: &mut R) -> Result<Self, DecodeError> {
 872                 use bitcoin::hashes::Hash;
 873
 874                 let buf: [u8; 32] = Readable::read(r)?;
 875                 Ok(Sha256dHash::from_slice(&buf[..]).unwrap())
 876         }
 877 }
 878
 879 impl Writeable for ecdsa::Signature {
 880         fn write<W: Writer>(&self, w: &mut W) -> Result<(), io::Error> {
 881                 self.serialize_compact().write(w)
 882         }
 883 }
 884
 885 impl Readable for ecdsa::Signature {
 886         fn read<R: Read>(r: &mut R) -> Result<Self, DecodeError> {
 887                 let buf: [u8; COMPACT_SIGNATURE_SIZE] = Readable::read(r)?;
 888                 match ecdsa::Signature::from_compact(&buf) {
 889                         Ok(sig) => Ok(sig),
 890                         Err(_) => return Err(DecodeError::InvalidValue),
 891                 }
 892         }
 893 }
 894
 895 impl Writeable for schnorr::Signature {
 896         fn write<W: Writer>(&self, w: &mut W) -> Result<(), io::Error> {
 897                 self.as_ref().write(w)
 898         }
 899 }
 900
 901 impl Readable for schnorr::Signature {
 902         fn read<R: Read>(r: &mut R) -> Result<Self, DecodeError> {
 903                 let buf: [u8; SCHNORR_SIGNATURE_SIZE] = Readable::read(r)?;
 904                 match schnorr::Signature::from_slice(&buf) {
 905                         Ok(sig) => Ok(sig),
 906                         Err(_) => return Err(DecodeError::InvalidValue),
 907                 }
 908         }
 909 }
 910
 911 impl Writeable for PaymentPreimage {
 912         fn write<W: Writer>(&self, w: &mut W) -> Result<(), io::Error> {
 913                 self.0.write(w)
 914         }
 915 }
 916
 917 impl Readable for PaymentPreimage {
 918         fn read<R: Read>(r: &mut R) -> Result<Self, DecodeError> {
 919                 let buf: [u8; 32] = Readable::read(r)?;
 920                 Ok(PaymentPreimage(buf))
 921         }
 922 }
 923
 924 impl Writeable for PaymentHash {
 925         fn write<W: Writer>(&self, w: &mut W) -> Result<(), io::Error> {
 926                 self.0.write(w)
 927         }
 928 }
 929
 930 impl Readable for PaymentHash {
 931         fn read<R: Read>(r: &mut R) -> Result<Self, DecodeError> {
 932                 let buf: [u8; 32] = Readable::read(r)?;
 933                 Ok(PaymentHash(buf))
 934         }
 935 }
 936
 937 impl Writeable for PaymentSecret {
 938         fn write<W: Writer>(&self, w: &mut W) -> Result<(), io::Error> {
 939                 self.0.write(w)
 940         }
 941 }
 942
 943 impl Readable for PaymentSecret {
 944         fn read<R: Read>(r: &mut R) -> Result<Self, DecodeError> {
 945                 let buf: [u8; 32] = Readable::read(r)?;
 946                 Ok(PaymentSecret(buf))
 947         }
 948 }
 949
 950 impl<T: Writeable> Writeable for Box<T> {
 951         fn write<W: Writer>(&self, w: &mut W) -> Result<(), io::Error> {
 952                 T::write(&**self, w)
 953         }
 954 }
 955
 956 impl<T: Readable> Readable for Box<T> {
 957         fn read<R: Read>(r: &mut R) -> Result<Self, DecodeError> {
 958                 Ok(Box::new(Readable::read(r)?))
 959         }
 960 }
 961
 962 impl<T: Writeable> Writeable for Option<T> {
 963         fn write<W: Writer>(&self, w: &mut W) -> Result<(), io::Error> {
 964                 match *self {
 965                         None => 0u8.write(w)?,
 966                         Some(ref data) => {
 967                                 BigSize(data.serialized_length() as u64 + 1).write(w)?;
 968                                 data.write(w)?;
 969                         }
 970                 }
 971                 Ok(())
 972         }
 973 }
 974
 975 impl<T: Readable> Readable for Option<T>
 976 {
 977         fn read<R: Read>(r: &mut R) -> Result<Self, DecodeError> {
 978                 let len: BigSize = Readable::read(r)?;
 979                 match len.0 {
 980                         0 => Ok(None),
 981                         len => {
 982                                 let mut reader = FixedLengthReader::new(r, len - 1);
 983                                 Ok(Some(Readable::read(&mut reader)?))
 984                         }
 985                 }
 986         }
 987 }
 988
 989 impl Writeable for Txid {
 990         fn write<W: Writer>(&self, w: &mut W) -> Result<(), io::Error> {
 991                 w.write_all(&self[..])
 992         }
 993 }
 994
 995 impl Readable for Txid {
 996         fn read<R: Read>(r: &mut R) -> Result<Self, DecodeError> {
 997                 use bitcoin::hashes::Hash;
 998
 999                 let buf: [u8; 32] = Readable::read(r)?;
1000                 Ok(Txid::from_slice(&buf[..]).unwrap())
1001         }
1002 }
1003
1004 impl Writeable for BlockHash {
1005         fn write<W: Writer>(&self, w: &mut W) -> Result<(), io::Error> {
1006                 w.write_all(&self[..])
1007         }
1008 }
1009
1010 impl Readable for BlockHash {
1011         fn read<R: Read>(r: &mut R) -> Result<Self, DecodeError> {
1012                 use bitcoin::hashes::Hash;
1013
1014                 let buf: [u8; 32] = Readable::read(r)?;
1015                 Ok(BlockHash::from_slice(&buf[..]).unwrap())
1016         }
1017 }
1018
1019 impl Writeable for ChainHash {
1020         fn write<W: Writer>(&self, w: &mut W) -> Result<(), io::Error> {
1021                 w.write_all(self.as_bytes())
1022         }
1023 }
1024
1025 impl Readable for ChainHash {
1026         fn read<R: Read>(r: &mut R) -> Result<Self, DecodeError> {
1027                 let buf: [u8; 32] = Readable::read(r)?;
1028                 Ok(ChainHash::from(&buf[..]))
1029         }
1030 }
1031
1032 impl Writeable for OutPoint {
1033         fn write<W: Writer>(&self, w: &mut W) -> Result<(), io::Error> {
1034                 self.txid.write(w)?;
1035                 self.vout.write(w)?;
1036                 Ok(())
1037         }
1038 }
1039
1040 impl Readable for OutPoint {
1041         fn read<R: Read>(r: &mut R) -> Result<Self, DecodeError> {
1042                 let txid = Readable::read(r)?;
1043                 let vout = Readable::read(r)?;
1044                 Ok(OutPoint {
1045                         txid,
1046                         vout,
1047                 })
1048         }
1049 }
1050
1051 macro_rules! impl_consensus_ser {
1052         ($bitcoin_type: ty) => {
1053                 impl Writeable for $bitcoin_type {
1054                         fn write<W: Writer>(&self, writer: &mut W) -> Result<(), io::Error> {
1055                                 match self.consensus_encode(&mut WriterWriteAdaptor(writer)) {
1056                                         Ok(_) => Ok(()),
1057                                         Err(e) => Err(e),
1058                                 }
1059                         }
1060                 }
1061
1062                 impl Readable for $bitcoin_type {
1063                         fn read<R: Read>(r: &mut R) -> Result<Self, DecodeError> {
1064                                 match consensus::encode::Decodable::consensus_decode(r) {
1065                                         Ok(t) => Ok(t),
1066                                         Err(consensus::encode::Error::Io(ref e)) if e.kind() == io::ErrorKind::UnexpectedEof => Err(DecodeError::ShortRead),
1067                                         Err(consensus::encode::Error::Io(e)) => Err(DecodeError::Io(e.kind())),
1068                                         Err(_) => Err(DecodeError::InvalidValue),
1069                                 }
1070                         }
1071                 }
1072         }
1073 }
1074 impl_consensus_ser!(Transaction);
1075 impl_consensus_ser!(TxOut);
1076
1077 impl<T: Readable> Readable for Mutex<T> {
1078         fn read<R: Read>(r: &mut R) -> Result<Self, DecodeError> {
1079                 let t: T = Readable::read(r)?;
1080                 Ok(Mutex::new(t))
1081         }
1082 }
1083 impl<T: Writeable> Writeable for Mutex<T> {
1084         fn write<W: Writer>(&self, w: &mut W) -> Result<(), io::Error> {
1085                 self.lock().unwrap().write(w)
1086         }
1087 }
1088
1089 impl<A: Readable, B: Readable> Readable for (A, B) {
1090         fn read<R: Read>(r: &mut R) -> Result<Self, DecodeError> {
1091                 let a: A = Readable::read(r)?;
1092                 let b: B = Readable::read(r)?;
1093                 Ok((a, b))
1094         }
1095 }
1096 impl<A: Writeable, B: Writeable> Writeable for (A, B) {
1097         fn write<W: Writer>(&self, w: &mut W) -> Result<(), io::Error> {
1098                 self.0.write(w)?;
1099                 self.1.write(w)
1100         }
1101 }
1102
1103 impl<A: Readable, B: Readable, C: Readable> Readable for (A, B, C) {
1104         fn read<R: Read>(r: &mut R) -> Result<Self, DecodeError> {
1105                 let a: A = Readable::read(r)?;
1106                 let b: B = Readable::read(r)?;
1107                 let c: C = Readable::read(r)?;
1108                 Ok((a, b, c))
1109         }
1110 }
1111 impl<A: Writeable, B: Writeable, C: Writeable> Writeable for (A, B, C) {
1112         fn write<W: Writer>(&self, w: &mut W) -> Result<(), io::Error> {
1113                 self.0.write(w)?;
1114                 self.1.write(w)?;
1115                 self.2.write(w)
1116         }
1117 }
1118
1119 impl<A: Readable, B: Readable, C: Readable, D: Readable> Readable for (A, B, C, D) {
1120         fn read<R: Read>(r: &mut R) -> Result<Self, DecodeError> {
1121                 let a: A = Readable::read(r)?;
1122                 let b: B = Readable::read(r)?;
1123                 let c: C = Readable::read(r)?;
1124                 let d: D = Readable::read(r)?;
1125                 Ok((a, b, c, d))
1126         }
1127 }
1128 impl<A: Writeable, B: Writeable, C: Writeable, D: Writeable> Writeable for (A, B, C, D) {
1129         fn write<W: Writer>(&self, w: &mut W) -> Result<(), io::Error> {
1130                 self.0.write(w)?;
1131                 self.1.write(w)?;
1132                 self.2.write(w)?;
1133                 self.3.write(w)
1134         }
1135 }
1136
1137 impl Writeable for () {
1138         fn write<W: Writer>(&self, _: &mut W) -> Result<(), io::Error> {
1139                 Ok(())
1140         }
1141 }
1142 impl Readable for () {
1143         fn read<R: Read>(_r: &mut R) -> Result<Self, DecodeError> {
1144                 Ok(())
1145         }
1146 }
1147
1148 impl Writeable for String {
1149         #[inline]
1150         fn write<W: Writer>(&self, w: &mut W) -> Result<(), io::Error> {
1151                 CollectionLength(self.len() as u64).write(w)?;
1152                 w.write_all(self.as_bytes())
1153         }
1154 }
1155 impl Readable for String {
1156         #[inline]
1157         fn read<R: Read>(r: &mut R) -> Result<Self, DecodeError> {
1158                 let v: Vec<u8> = Readable::read(r)?;
1159                 let ret = String::from_utf8(v).map_err(|_| DecodeError::InvalidValue)?;
1160                 Ok(ret)
1161         }
1162 }
1163
1164 /// Represents a hostname for serialization purposes.
1165 /// Only the character set and length will be validated.
1166 /// The character set consists of ASCII alphanumeric characters, hyphens, and periods.
1167 /// Its length is guaranteed to be representable by a single byte.
1168 /// This serialization is used by [`BOLT 7`] hostnames.
1169 ///
1170 /// [`BOLT 7`]: https://github.com/lightning/bolts/blob/master/07-routing-gossip.md
1171 #[derive(Clone, Debug, PartialEq, Eq)]
1172 pub struct Hostname(String);
1173 impl Hostname {
1174         /// Returns the length of the hostname.
1175         pub fn len(&self) -> u8 {
1176                 (&self.0).len() as u8
1177         }
1178 }
1179 impl Deref for Hostname {
1180         type Target = String;
1181
1182         fn deref(&self) -> &Self::Target {
1183                 &self.0
1184         }
1185 }
1186 impl From<Hostname> for String {
1187         fn from(hostname: Hostname) -> Self {
1188                 hostname.0
1189         }
1190 }
1191 impl TryFrom<Vec<u8>> for Hostname {
1192         type Error = ();
1193
1194         fn try_from(bytes: Vec<u8>) -> Result<Self, Self::Error> {
1195                 if let Ok(s) = String::from_utf8(bytes) {
1196                         Hostname::try_from(s)
1197                 } else {
1198                         Err(())
1199                 }
1200         }
1201 }
1202 impl TryFrom<String> for Hostname {
1203         type Error = ();
1204
1205         fn try_from(s: String) -> Result<Self, Self::Error> {
1206                 if s.len() <= 255 && s.chars().all(|c|
1207                         c.is_ascii_alphanumeric() ||
1208                         c == '.' ||
1209                         c == '-'
1210                 ) {
1211                         Ok(Hostname(s))
1212                 } else {
1213                         Err(())
1214                 }
1215         }
1216 }
1217 impl Writeable for Hostname {
1218         #[inline]
1219         fn write<W: Writer>(&self, w: &mut W) -> Result<(), io::Error> {
1220                 self.len().write(w)?;
1221                 w.write_all(self.as_bytes())
1222         }
1223 }
1224 impl Readable for Hostname {
1225         #[inline]
1226         fn read<R: Read>(r: &mut R) -> Result<Hostname, DecodeError> {
1227                 let len: u8 = Readable::read(r)?;
1228                 let mut vec = Vec::with_capacity(len.into());
1229                 vec.resize(len.into(), 0);
1230                 r.read_exact(&mut vec)?;
1231                 Hostname::try_from(vec).map_err(|_| DecodeError::InvalidValue)
1232         }
1233 }
1234
1235 impl Writeable for Duration {
1236         #[inline]
1237         fn write<W: Writer>(&self, w: &mut W) -> Result<(), io::Error> {
1238                 self.as_secs().write(w)?;
1239                 self.subsec_nanos().write(w)
1240         }
1241 }
1242 impl Readable for Duration {
1243         #[inline]
1244         fn read<R: Read>(r: &mut R) -> Result<Self, DecodeError> {
1245                 let secs = Readable::read(r)?;
1246                 let nanos = Readable::read(r)?;
1247                 Ok(Duration::new(secs, nanos))
1248         }
1249 }
1250
1251 #[cfg(test)]
1252 mod tests {
1253         use core::convert::TryFrom;
1254         use crate::util::ser::{Readable, Hostname, Writeable};
1255
1256         #[test]
1257         fn hostname_conversion() {
1258                 assert_eq!(Hostname::try_from(String::from("a-test.com")).unwrap().as_str(), "a-test.com");
1259
1260                 assert!(Hostname::try_from(String::from("\"")).is_err());
1261                 assert!(Hostname::try_from(String::from("$")).is_err());
1262                 assert!(Hostname::try_from(String::from("⚡")).is_err());
1263                 let mut large_vec = Vec::with_capacity(256);
1264                 large_vec.resize(256, b'A');
1265                 assert!(Hostname::try_from(String::from_utf8(large_vec).unwrap()).is_err());
1266         }
1267
1268         #[test]
1269         fn hostname_serialization() {
1270                 let hostname = Hostname::try_from(String::from("test")).unwrap();
1271                 let mut buf: Vec<u8> = Vec::new();
1272                 hostname.write(&mut buf).unwrap();
1273                 assert_eq!(Hostname::read(&mut buf.as_slice()).unwrap().as_str(), "test");
1274         }
1275
1276         #[test]
1277         fn bigsize_encoding_decoding() {
1278                 let values = vec![0, 252, 253, 65535, 65536, 4294967295, 4294967296, 18446744073709551615];
1279                 let bytes = vec![
1280                         "00",
1281                         "fc",
1282                         "fd00fd",
1283                         "fdffff",
1284                         "fe00010000",
1285                         "feffffffff",
1286                         "ff0000000100000000",
1287                         "ffffffffffffffffff"
1288                 ];
1289                 for i in 0..=7 {
1290                         let mut stream = crate::io::Cursor::new(::hex::decode(bytes[i]).unwrap());
1291                         assert_eq!(super::BigSize::read(&mut stream).unwrap().0, values[i]);
1292                         let mut stream = super::VecWriter(Vec::new());
1293                         super::BigSize(values[i]).write(&mut stream).unwrap();
1294                         assert_eq!(stream.0, ::hex::decode(bytes[i]).unwrap());
1295                 }
1296                 let err_bytes = vec![
1297                         "fd00fc",
1298                         "fe0000ffff",
1299                         "ff00000000ffffffff",
1300                         "fd00",
1301                         "feffff",
1302                         "ffffffffff",
1303                         "fd",
1304                         "fe",
1305                         "ff",
1306                         ""
1307                 ];
1308                 for i in 0..=9 {
1309                         let mut stream = crate::io::Cursor::new(::hex::decode(err_bytes[i]).unwrap());
1310                         if i < 3 {
1311                                 assert_eq!(super::BigSize::read(&mut stream).err(), Some(crate::ln::msgs::DecodeError::InvalidValue));
1312                         } else {
1313                                 assert_eq!(super::BigSize::read(&mut stream).err(), Some(crate::ln::msgs::DecodeError::ShortRead));
1314                         }
1315                 }
1316         }
1317 }