X-Git-Url: http://git.bitcoin.ninja/index.cgi?a=blobdiff_plain;f=lightning%2Fsrc%2Futil%2Fser.rs;h=af4de88a1a7dda59145b1ea25fa7b7e434519f76;hb=1ac53ed02bf26520d3b1a2c3c0e90c8691c83099;hp=02d4a81b39e4418daf45f6cb6fc6f61180b1785e;hpb=4a0010d7393bb32305bdb3d859735b7b563462eb;p=rust-lightning

diff --git a/lightning/src/util/ser.rs b/lightning/src/util/ser.rs
index 02d4a81b..af4de88a 100644
--- a/lightning/src/util/ser.rs
+++ b/lightning/src/util/ser.rs
@@ -8,7 +8,10 @@
 // licenses.
 
 //! A very simple serialization framework which is used to serialize/deserialize messages as well
-//! as ChannelsManagers and ChannelMonitors.
+//! as [`ChannelManager`]s and [`ChannelMonitor`]s.
+//!
+//! [`ChannelManager`]: crate::ln::channelmanager::ChannelManager
+//! [`ChannelMonitor`]: crate::chain::channelmonitor::ChannelMonitor
 
 use crate::prelude::*;
 use crate::io::{self, Read, Seek, Write};
@@ -19,31 +22,37 @@ use core::cmp;
 use core::convert::TryFrom;
 use core::ops::Deref;
 
+use alloc::collections::BTreeMap;
+
 use bitcoin::secp256k1::{PublicKey, SecretKey};
 use bitcoin::secp256k1::constants::{PUBLIC_KEY_SIZE, SECRET_KEY_SIZE, COMPACT_SIGNATURE_SIZE, SCHNORR_SIGNATURE_SIZE};
 use bitcoin::secp256k1::ecdsa;
 use bitcoin::secp256k1::schnorr;
 use bitcoin::blockdata::constants::ChainHash;
-use bitcoin::blockdata::script::Script;
+use bitcoin::blockdata::script::{self, Script};
 use bitcoin::blockdata::transaction::{OutPoint, Transaction, TxOut};
-use bitcoin::consensus;
+use bitcoin::{consensus, Witness};
 use bitcoin::consensus::Encodable;
 use bitcoin::hashes::sha256d::Hash as Sha256dHash;
 use bitcoin::hash_types::{Txid, BlockHash};
 use core::marker::Sized;
 use core::time::Duration;
+use crate::chain::ClaimId;
 use crate::ln::msgs::DecodeError;
+#[cfg(taproot)]
+use crate::ln::msgs::PartialSignatureWithNonce;
 use crate::ln::{PaymentPreimage, PaymentHash, PaymentSecret};
 
 use crate::util::byte_utils::{be48_to_array, slice_to_be48};
+use crate::util::string::UntrustedString;
 
 /// serialization buffer size
 pub const MAX_BUF_SIZE: usize = 64 * 1024;
 
-/// A simplified version of std::io::Write that exists largely for backwards compatibility.
-/// An impl is provided for any type that also impls std::io::Write.
+/// A simplified version of [`std::io::Write`] that exists largely for backwards compatibility.
+/// An impl is provided for any type that also impls [`std::io::Write`].
 ///
-/// (C-not exported) as we only export serialization to/from byte arrays instead
+/// This is not exported to bindings users as we only export serialization to/from byte arrays instead
 pub trait Writer {
 	/// Writes the given buf out. See std::io::Write::write_all for more
 	fn write_all(&mut self, buf: &[u8]) -> Result<(), io::Error>;
@@ -84,7 +93,9 @@ impl Writer for VecWriter {
 
 /// Writer that only tracks the amount of data written - useful if you need to calculate the length
 /// of some data when serialized but don't yet need the full data.
-pub(crate) struct LengthCalculatingWriter(pub usize);
+///
+/// This is not exported to bindings users as manual TLV building is not currently supported in bindings
+pub struct LengthCalculatingWriter(pub usize);
 impl Writer for LengthCalculatingWriter {
 	#[inline]
 	fn write_all(&mut self, buf: &[u8]) -> Result<(), io::Error> {
@@ -93,23 +104,28 @@ impl Writer for LengthCalculatingWriter {
 	}
 }
 
-/// Essentially std::io::Take but a bit simpler and with a method to walk the underlying stream
+/// Essentially [`std::io::Take`] but a bit simpler and with a method to walk the underlying stream
 /// forward to ensure we always consume exactly the fixed length specified.
-pub(crate) struct FixedLengthReader<R: Read> {
+///
+/// This is not exported to bindings users as manual TLV building is not currently supported in bindings
+pub struct FixedLengthReader<R: Read> {
 	read: R,
 	bytes_read: u64,
 	total_bytes: u64,
 }
 impl<R: Read> FixedLengthReader<R> {
+	/// Returns a new [`FixedLengthReader`].
 	pub fn new(read: R, total_bytes: u64) -> Self {
 		Self { read, bytes_read: 0, total_bytes }
 	}
 
+	/// Returns whether some bytes are remaining or not.
 	#[inline]
 	pub fn bytes_remain(&mut self) -> bool {
 		self.bytes_read != self.total_bytes
 	}
 
+	/// Consumes the remaining bytes.
 	#[inline]
 	pub fn eat_remaining(&mut self) -> Result<(), DecodeError> {
 		copy(self, &mut sink()).unwrap();
@@ -145,13 +161,17 @@ impl<R: Read> LengthRead for FixedLengthReader<R> {
 	}
 }
 
-/// A Read which tracks whether any bytes have been read at all. This allows us to distinguish
+/// A [`Read`] implementation which tracks whether any bytes have been read at all. This allows us to distinguish
 /// between "EOF reached before we started" and "EOF reached mid-read".
-pub(crate) struct ReadTrackingReader<R: Read> {
+///
+/// This is not exported to bindings users as manual TLV building is not currently supported in bindings
+pub struct ReadTrackingReader<R: Read> {
 	read: R,
+	/// Returns whether we have read from this reader or not yet.
 	pub have_read: bool,
 }
 impl<R: Read> ReadTrackingReader<R> {
+	/// Returns a new [`ReadTrackingReader`].
 	pub fn new(read: R) -> Self {
 		Self { read, have_read: false }
 	}
@@ -170,21 +190,21 @@ impl<R: Read> Read for ReadTrackingReader<R> {
 	}
 }
 
-/// A trait that various rust-lightning types implement allowing them to be written out to a Writer
+/// A trait that various LDK types implement allowing them to be written out to a [`Writer`].
 ///
-/// (C-not exported) as we only export serialization to/from byte arrays instead
+/// This is not exported to bindings users as we only export serialization to/from byte arrays instead
 pub trait Writeable {
-	/// Writes self out to the given Writer
+	/// Writes `self` out to the given [`Writer`].
 	fn write<W: Writer>(&self, writer: &mut W) -> Result<(), io::Error>;
 
-	/// Writes self out to a Vec<u8>
+	/// Writes `self` out to a `Vec<u8>`.
 	fn encode(&self) -> Vec<u8> {
 		let mut msg = VecWriter(Vec::new());
 		self.write(&mut msg).unwrap();
 		msg.0
 	}
 
-	/// Writes self out to a Vec<u8>
+	/// Writes `self` out to a `Vec<u8>`.
 	#[cfg(test)]
 	fn encode_with_len(&self) -> Vec<u8> {
 		let mut msg = VecWriter(Vec::new());
@@ -210,64 +230,64 @@ impl<'a, T: Writeable> Writeable for &'a T {
 	fn write<W: Writer>(&self, writer: &mut W) -> Result<(), io::Error> { (*self).write(writer) }
 }
 
-/// A trait that various rust-lightning types implement allowing them to be read in from a Read
+/// A trait that various LDK types implement allowing them to be read in from a [`Read`].
 ///
-/// (C-not exported) as we only export serialization to/from byte arrays instead
+/// This is not exported to bindings users as we only export serialization to/from byte arrays instead
 pub trait Readable
 	where Self: Sized
 {
-	/// Reads a Self in from the given Read
+	/// Reads a `Self` in from the given [`Read`].
 	fn read<R: Read>(reader: &mut R) -> Result<Self, DecodeError>;
 }
 
-/// A trait that various rust-lightning types implement allowing them to be read in from a
-/// `Read + Seek`.
+/// A trait that various LDK types implement allowing them to be read in from a
+/// [`Read`]` + `[`Seek`].
 pub(crate) trait SeekReadable where Self: Sized {
-	/// Reads a Self in from the given Read
+	/// Reads a `Self` in from the given [`Read`].
 	fn read<R: Read + Seek>(reader: &mut R) -> Result<Self, DecodeError>;
 }
 
-/// A trait that various higher-level rust-lightning types implement allowing them to be read in
-/// from a Read given some additional set of arguments which is required to deserialize.
+/// A trait that various higher-level LDK types implement allowing them to be read in
+/// from a [`Read`] given some additional set of arguments which is required to deserialize.
 ///
-/// (C-not exported) as we only export serialization to/from byte arrays instead
+/// This is not exported to bindings users as we only export serialization to/from byte arrays instead
 pub trait ReadableArgs<P>
 	where Self: Sized
 {
-	/// Reads a Self in from the given Read
+	/// Reads a `Self` in from the given [`Read`].
 	fn read<R: Read>(reader: &mut R, params: P) -> Result<Self, DecodeError>;
 }
 
-/// A std::io::Read that also provides the total bytes available to read.
+/// A [`std::io::Read`] that also provides the total bytes available to be read.
 pub(crate) trait LengthRead: Read {
-	/// The total number of bytes available to read.
+	/// The total number of bytes available to be read.
 	fn total_bytes(&self) -> u64;
 }
 
-/// A trait that various higher-level rust-lightning types implement allowing them to be read in
+/// A trait that various higher-level LDK types implement allowing them to be read in
 /// from a Read given some additional set of arguments which is required to deserialize, requiring
 /// the implementer to provide the total length of the read.
 pub(crate) trait LengthReadableArgs<P> where Self: Sized
 {
-	/// Reads a Self in from the given LengthRead
+	/// Reads a `Self` in from the given [`LengthRead`].
 	fn read<R: LengthRead>(reader: &mut R, params: P) -> Result<Self, DecodeError>;
 }
 
-/// A trait that various higher-level rust-lightning types implement allowing them to be read in
-/// from a Read, requiring the implementer to provide the total length of the read.
+/// A trait that various higher-level LDK types implement allowing them to be read in
+/// from a [`Read`], requiring the implementer to provide the total length of the read.
 pub(crate) trait LengthReadable where Self: Sized
 {
-	/// Reads a Self in from the given LengthRead
+	/// Reads a `Self` in from the given [`LengthRead`].
 	fn read<R: LengthRead>(reader: &mut R) -> Result<Self, DecodeError>;
 }
 
-/// A trait that various rust-lightning types implement allowing them to (maybe) be read in from a Read
+/// A trait that various LDK types implement allowing them to (maybe) be read in from a [`Read`].
 ///
-/// (C-not exported) as we only export serialization to/from byte arrays instead
+/// This is not exported to bindings users as we only export serialization to/from byte arrays instead
 pub trait MaybeReadable
 	where Self: Sized
 {
-	/// Reads a Self in from the given Read
+	/// Reads a `Self` in from the given [`Read`].
 	fn read<R: Read>(reader: &mut R) -> Result<Option<Self>, DecodeError>;
 }
 
@@ -278,18 +298,41 @@ impl<T: Readable> MaybeReadable for T {
 	}
 }
 
-pub(crate) struct OptionDeserWrapper<T: Readable>(pub Option<T>);
-impl<T: Readable> Readable for OptionDeserWrapper<T> {
+/// Wrapper to read a required (non-optional) TLV record.
+///
+/// This is not exported to bindings users as manual TLV building is not currently supported in bindings
+pub struct RequiredWrapper<T>(pub Option<T>);
+impl<T: Readable> Readable for RequiredWrapper<T> {
 	#[inline]
 	fn read<R: Read>(reader: &mut R) -> Result<Self, DecodeError> {
 		Ok(Self(Some(Readable::read(reader)?)))
 	}
 }
-/// When handling default_values, we want to map the default-value T directly
-/// to a OptionDeserWrapper<T> in a way that works for `field: T = t;` as
+impl<A, T: ReadableArgs<A>> ReadableArgs<A> for RequiredWrapper<T> {
+	#[inline]
+	fn read<R: Read>(reader: &mut R, args: A) -> Result<Self, DecodeError> {
+		Ok(Self(Some(ReadableArgs::read(reader, args)?)))
+	}
+}
+/// When handling `default_values`, we want to map the default-value T directly
+/// to a `RequiredWrapper<T>` in a way that works for `field: T = t;` as
 /// well. Thus, we assume `Into<T> for T` does nothing and use that.
-impl<T: Readable> From<T> for OptionDeserWrapper<T> {
-	fn from(t: T) -> OptionDeserWrapper<T> { OptionDeserWrapper(Some(t)) }
+impl<T> From<T> for RequiredWrapper<T> {
+	fn from(t: T) -> RequiredWrapper<T> { RequiredWrapper(Some(t)) }
+}
+
+/// Wrapper to read a required (non-optional) TLV record that may have been upgraded without
+/// backwards compat.
+///
+/// This is not exported to bindings users as manual TLV building is not currently supported in bindings
+pub struct UpgradableRequired<T: MaybeReadable>(pub Option<T>);
+impl<T: MaybeReadable> MaybeReadable for UpgradableRequired<T> {
+	#[inline]
+	fn read<R: Read>(reader: &mut R) -> Result<Option<Self>, DecodeError> {
+		let tlv = MaybeReadable::read(reader)?;
+		if let Some(tlv) = tlv { return Ok(Some(Self(Some(tlv)))) }
+		Ok(None)
+	}
 }
 
 pub(crate) struct U48(pub u64);
@@ -308,13 +351,14 @@ impl Readable for U48 {
 	}
 }
 
-/// Lightning TLV uses a custom variable-length integer called BigSize. It is similar to Bitcoin's
+/// Lightning TLV uses a custom variable-length integer called `BigSize`. It is similar to Bitcoin's
 /// variable-length integers except that it is serialized in big-endian instead of little-endian.
 ///
 /// Like Bitcoin's variable-length integer, it exhibits ambiguity in that certain values can be
 /// encoded in several different ways, which we must check for at deserialization-time. Thus, if
 /// you're looking for an example of a variable-length integer to use for your own project, move
 /// along, this is a rather poor design.
+#[derive(Clone, Copy, Debug, Hash, PartialOrd, Ord, PartialEq, Eq)]
 pub struct BigSize(pub u64);
 impl Writeable for BigSize {
 	#[inline]
@@ -372,9 +416,43 @@ impl Readable for BigSize {
 	}
 }
 
+/// The lightning protocol uses u16s for lengths in most cases. As our serialization framework
+/// primarily targets that, we must as well. However, because we may serialize objects that have
+/// more than 65K entries, we need to be able to store larger values. Thus, we define a variable
+/// length integer here that is backwards-compatible for values < 0xffff. We treat 0xffff as
+/// "read eight more bytes".
+///
+/// To ensure we only have one valid encoding per value, we add 0xffff to values written as eight
+/// bytes. Thus, 0xfffe is serialized as 0xfffe, whereas 0xffff is serialized as
+/// 0xffff0000000000000000 (i.e. read-eight-bytes then zero).
+struct CollectionLength(pub u64);
+impl Writeable for CollectionLength {
+	#[inline]
+	fn write<W: Writer>(&self, writer: &mut W) -> Result<(), io::Error> {
+		if self.0 < 0xffff {
+			(self.0 as u16).write(writer)
+		} else {
+			0xffffu16.write(writer)?;
+			(self.0 - 0xffff).write(writer)
+		}
+	}
+}
+
+impl Readable for CollectionLength {
+	#[inline]
+	fn read<R: Read>(r: &mut R) -> Result<Self, DecodeError> {
+		let mut val: u64 = <u16 as Readable>::read(r)? as u64;
+		if val == 0xffff {
+			val = <u64 as Readable>::read(r)?
+				.checked_add(0xffff).ok_or(DecodeError::InvalidValue)?;
+		}
+		Ok(CollectionLength(val))
+	}
+}
+
 /// In TLV we occasionally send fields which only consist of, or potentially end with, a
 /// variable-length integer which is simply truncated by skipping high zero bytes. This type
-/// encapsulates such integers implementing Readable/Writeable for them.
+/// encapsulates such integers implementing [`Readable`]/[`Writeable`] for them.
 #[cfg_attr(test, derive(PartialEq, Eq, Debug))]
 pub(crate) struct HighZeroBytesDroppedBigSize<T>(pub T);
 
@@ -437,6 +515,10 @@ impl_writeable_primitive!(u128, 16);
 impl_writeable_primitive!(u64, 8);
 impl_writeable_primitive!(u32, 4);
 impl_writeable_primitive!(u16, 2);
+impl_writeable_primitive!(i64, 8);
+impl_writeable_primitive!(i32, 4);
+impl_writeable_primitive!(i16, 2);
+impl_writeable_primitive!(i8, 1);
 
 impl Writeable for u8 {
 	#[inline]
@@ -471,64 +553,56 @@ impl Readable for bool {
 	}
 }
 
-// u8 arrays
 macro_rules! impl_array {
-	( $size:expr ) => (
-		impl Writeable for [u8; $size]
-		{
+	($size:expr, $ty: ty) => (
+		impl Writeable for [$ty; $size] {
 			#[inline]
 			fn write<W: Writer>(&self, w: &mut W) -> Result<(), io::Error> {
-				w.write_all(self)
+				let mut out = [0; $size * core::mem::size_of::<$ty>()];
+				for (idx, v) in self.iter().enumerate() {
+					let startpos = idx * core::mem::size_of::<$ty>();
+					out[startpos..startpos + core::mem::size_of::<$ty>()].copy_from_slice(&v.to_be_bytes());
+				}
+				w.write_all(&out)
 			}
 		}
 
-		impl Readable for [u8; $size]
-		{
+		impl Readable for [$ty; $size] {
 			#[inline]
 			fn read<R: Read>(r: &mut R) -> Result<Self, DecodeError> {
-				let mut buf = [0u8; $size];
+				let mut buf = [0u8; $size * core::mem::size_of::<$ty>()];
 				r.read_exact(&mut buf)?;
-				Ok(buf)
+				let mut res = [0; $size];
+				for (idx, v) in res.iter_mut().enumerate() {
+					let startpos = idx * core::mem::size_of::<$ty>();
+					let mut arr = [0; core::mem::size_of::<$ty>()];
+					arr.copy_from_slice(&buf[startpos..startpos + core::mem::size_of::<$ty>()]);
+					*v = <$ty>::from_be_bytes(arr);
+				}
+				Ok(res)
 			}
 		}
 	);
 }
 
-impl_array!(3); // for rgb, ISO 4712 code
-impl_array!(4); // for IPv4
-impl_array!(12); // for OnionV2
-impl_array!(16); // for IPv6
-impl_array!(32); // for channel id & hmac
-impl_array!(PUBLIC_KEY_SIZE); // for PublicKey
-impl_array!(64); // for ecdsa::Signature and schnorr::Signature
-impl_array!(1300); // for OnionPacket.hop_data
+impl_array!(3, u8); // for rgb, ISO 4712 code
+impl_array!(4, u8); // for IPv4
+impl_array!(12, u8); // for OnionV2
+impl_array!(16, u8); // for IPv6
+impl_array!(32, u8); // for channel id & hmac
+impl_array!(PUBLIC_KEY_SIZE, u8); // for PublicKey
+impl_array!(64, u8); // for ecdsa::Signature and schnorr::Signature
+impl_array!(66, u8); // for MuSig2 nonces
+impl_array!(1300, u8); // for OnionPacket.hop_data
 
-impl Writeable for [u16; 8] {
-	#[inline]
-	fn write<W: Writer>(&self, w: &mut W) -> Result<(), io::Error> {
-		for v in self.iter() {
-			w.write_all(&v.to_be_bytes())?
-		}
-		Ok(())
-	}
-}
+impl_array!(8, u16);
+impl_array!(32, u16);
 
-impl Readable for [u16; 8] {
-	#[inline]
-	fn read<R: Read>(r: &mut R) -> Result<Self, DecodeError> {
-		let mut buf = [0u8; 16];
-		r.read_exact(&mut buf)?;
-		let mut res = [0u16; 8];
-		for (idx, v) in res.iter_mut().enumerate() {
-			*v = (buf[idx] as u16) << 8 | (buf[idx + 1] as u16)
-		}
-		Ok(res)
-	}
-}
-
-/// For variable-length values within TLV record where the length is encoded as part of the record.
+/// A type for variable-length values within TLV record where the length is encoded as part of the record.
 /// Used to prevent encoding the length twice.
-pub(crate) struct WithoutLength<T>(pub T);
+///
+/// This is not exported to bindings users as manual TLV building is not currently supported in bindings
+pub struct WithoutLength<T>(pub T);
 
 impl Writeable for WithoutLength<&String> {
 	#[inline]
@@ -547,6 +621,21 @@ impl<'a> From<&'a String> for WithoutLength<&'a String> {
 	fn from(s: &'a String) -> Self { Self(s) }
 }
 
+
+impl Writeable for WithoutLength<&UntrustedString> {
+	#[inline]
+	fn write<W: Writer>(&self, w: &mut W) -> Result<(), io::Error> {
+		WithoutLength(&self.0.0).write(w)
+	}
+}
+impl Readable for WithoutLength<UntrustedString> {
+	#[inline]
+	fn read<R: Read>(r: &mut R) -> Result<Self, DecodeError> {
+		let s: WithoutLength<String> = Readable::read(r)?;
+		Ok(Self(UntrustedString(s.0)))
+	}
+}
+
 impl<'a, T: Writeable> Writeable for WithoutLength<&'a Vec<T>> {
 	#[inline]
 	fn write<W: Writer>(&self, writer: &mut W) -> Result<(), io::Error> {
@@ -579,50 +668,89 @@ impl<'a, T> From<&'a Vec<T>> for WithoutLength<&'a Vec<T>> {
 	fn from(v: &'a Vec<T>) -> Self { Self(v) }
 }
 
-// HashMap
-impl<K, V> Writeable for HashMap<K, V>
-	where K: Writeable + Eq + Hash,
-	      V: Writeable
-{
+impl Writeable for WithoutLength<&Script> {
 	#[inline]
-	fn write<W: Writer>(&self, w: &mut W) -> Result<(), io::Error> {
-	(self.len() as u16).write(w)?;
-		for (key, value) in self.iter() {
-			key.write(w)?;
-			value.write(w)?;
-		}
-		Ok(())
+	fn write<W: Writer>(&self, writer: &mut W) -> Result<(), io::Error> {
+		writer.write_all(self.0.as_bytes())
 	}
 }
 
-impl<K, V> Readable for HashMap<K, V>
-	where K: Readable + Eq + Hash,
-	      V: MaybeReadable
-{
+impl Readable for WithoutLength<Script> {
 	#[inline]
 	fn read<R: Read>(r: &mut R) -> Result<Self, DecodeError> {
-		let len: u16 = Readable::read(r)?;
-		let mut ret = HashMap::with_capacity(len as usize);
-		for _ in 0..len {
-			let k = K::read(r)?;
-			let v_opt = V::read(r)?;
-			if let Some(v) = v_opt {
-				if ret.insert(k, v).is_some() {
-					return Err(DecodeError::InvalidValue);
+		let v: WithoutLength<Vec<u8>> = Readable::read(r)?;
+		Ok(WithoutLength(script::Builder::from(v.0).into_script()))
+	}
+}
+
+#[derive(Debug)]
+pub(crate) struct Iterable<'a, I: Iterator<Item = &'a T> + Clone, T: 'a>(pub I);
+
+impl<'a, I: Iterator<Item = &'a T> + Clone, T: 'a + Writeable> Writeable for Iterable<'a, I, T> {
+	#[inline]
+	fn write<W: Writer>(&self, writer: &mut W) -> Result<(), io::Error> {
+		for ref v in self.0.clone() {
+			v.write(writer)?;
+		}
+		Ok(())
+	}
+}
+
+#[cfg(test)]
+impl<'a, I: Iterator<Item = &'a T> + Clone, T: 'a + PartialEq> PartialEq for Iterable<'a, I, T> {
+	fn eq(&self, other: &Self) -> bool {
+		self.0.clone().collect::<Vec<_>>() == other.0.clone().collect::<Vec<_>>()
+	}
+}
+
+macro_rules! impl_for_map {
+	($ty: ident, $keybound: ident, $constr: expr) => {
+		impl<K, V> Writeable for $ty<K, V>
+			where K: Writeable + Eq + $keybound, V: Writeable
+		{
+			#[inline]
+			fn write<W: Writer>(&self, w: &mut W) -> Result<(), io::Error> {
+				CollectionLength(self.len() as u64).write(w)?;
+				for (key, value) in self.iter() {
+					key.write(w)?;
+					value.write(w)?;
 				}
+				Ok(())
+			}
+		}
+
+		impl<K, V> Readable for $ty<K, V>
+			where K: Readable + Eq + $keybound, V: MaybeReadable
+		{
+			#[inline]
+			fn read<R: Read>(r: &mut R) -> Result<Self, DecodeError> {
+				let len: CollectionLength = Readable::read(r)?;
+				let mut ret = $constr(len.0 as usize);
+				for _ in 0..len.0 {
+					let k = K::read(r)?;
+					let v_opt = V::read(r)?;
+					if let Some(v) = v_opt {
+						if ret.insert(k, v).is_some() {
+							return Err(DecodeError::InvalidValue);
+						}
+					}
+				}
+				Ok(ret)
 			}
 		}
-		Ok(ret)
 	}
 }
 
+impl_for_map!(BTreeMap, Ord, |_| BTreeMap::new());
+impl_for_map!(HashMap, Hash, |len| HashMap::with_capacity(len));
+
 // HashSet
 impl<T> Writeable for HashSet<T>
 where T: Writeable + Eq + Hash
 {
 	#[inline]
 	fn write<W: Writer>(&self, w: &mut W) -> Result<(), io::Error> {
-		(self.len() as u16).write(w)?;
+		CollectionLength(self.len() as u64).write(w)?;
 		for item in self.iter() {
 			item.write(w)?;
 		}
@@ -635,9 +763,9 @@ where T: Readable + Eq + Hash
 {
 	#[inline]
 	fn read<R: Read>(r: &mut R) -> Result<Self, DecodeError> {
-		let len: u16 = Readable::read(r)?;
-		let mut ret = HashSet::with_capacity(len as usize);
-		for _ in 0..len {
+		let len: CollectionLength = Readable::read(r)?;
+		let mut ret = HashSet::with_capacity(cmp::min(len.0 as usize, MAX_BUF_SIZE / core::mem::size_of::<T>()));
+		for _ in 0..len.0 {
 			if !ret.insert(T::read(r)?) {
 				return Err(DecodeError::InvalidValue)
 			}
@@ -647,10 +775,48 @@ where T: Readable + Eq + Hash
 }
 
 // Vectors
+macro_rules! impl_writeable_for_vec {
+	($ty: ty $(, $name: ident)*) => {
+		impl<$($name : Writeable),*> Writeable for Vec<$ty> {
+			#[inline]
+			fn write<W: Writer>(&self, w: &mut W) -> Result<(), io::Error> {
+				CollectionLength(self.len() as u64).write(w)?;
+				for elem in self.iter() {
+					elem.write(w)?;
+				}
+				Ok(())
+			}
+		}
+	}
+}
+macro_rules! impl_readable_for_vec {
+	($ty: ty $(, $name: ident)*) => {
+		impl<$($name : Readable),*> Readable for Vec<$ty> {
+			#[inline]
+			fn read<R: Read>(r: &mut R) -> Result<Self, DecodeError> {
+				let len: CollectionLength = Readable::read(r)?;
+				let mut ret = Vec::with_capacity(cmp::min(len.0 as usize, MAX_BUF_SIZE / core::mem::size_of::<$ty>()));
+				for _ in 0..len.0 {
+					if let Some(val) = MaybeReadable::read(r)? {
+						ret.push(val);
+					}
+				}
+				Ok(ret)
+			}
+		}
+	}
+}
+macro_rules! impl_for_vec {
+	($ty: ty $(, $name: ident)*) => {
+		impl_writeable_for_vec!($ty $(, $name)*);
+		impl_readable_for_vec!($ty $(, $name)*);
+	}
+}
+
 impl Writeable for Vec<u8> {
 	#[inline]
 	fn write<W: Writer>(&self, w: &mut W) -> Result<(), io::Error> {
-		(self.len() as u16).write(w)?;
+		CollectionLength(self.len() as u64).write(w)?;
 		w.write_all(&self)
 	}
 }
@@ -658,37 +824,57 @@ impl Writeable for Vec<u8> {
 impl Readable for Vec<u8> {
 	#[inline]
 	fn read<R: Read>(r: &mut R) -> Result<Self, DecodeError> {
-		let len: u16 = Readable::read(r)?;
-		let mut ret = Vec::with_capacity(len as usize);
-		ret.resize(len as usize, 0);
-		r.read_exact(&mut ret)?;
+		let mut len: CollectionLength = Readable::read(r)?;
+		let mut ret = Vec::new();
+		while len.0 > 0 {
+			let readamt = cmp::min(len.0 as usize, MAX_BUF_SIZE);
+			let readstart = ret.len();
+			ret.resize(readstart + readamt, 0);
+			r.read_exact(&mut ret[readstart..])?;
+			len.0 -= readamt as u64;
+		}
 		Ok(ret)
 	}
 }
-impl Writeable for Vec<ecdsa::Signature> {
+
+impl_for_vec!(ecdsa::Signature);
+impl_for_vec!(crate::chain::channelmonitor::ChannelMonitorUpdate);
+impl_for_vec!(crate::ln::channelmanager::MonitorUpdateCompletionAction);
+impl_for_vec!((A, B), A, B);
+impl_writeable_for_vec!(&crate::routing::router::BlindedTail);
+impl_readable_for_vec!(crate::routing::router::BlindedTail);
+
+impl Writeable for Vec<Witness> {
 	#[inline]
 	fn write<W: Writer>(&self, w: &mut W) -> Result<(), io::Error> {
 		(self.len() as u16).write(w)?;
-		for e in self.iter() {
-			e.write(w)?;
+		for witness in self {
+			(witness.serialized_len() as u16).write(w)?;
+			witness.write(w)?;
 		}
 		Ok(())
 	}
 }
 
-impl Readable for Vec<ecdsa::Signature> {
+impl Readable for Vec<Witness> {
 	#[inline]
 	fn read<R: Read>(r: &mut R) -> Result<Self, DecodeError> {
-		let len: u16 = Readable::read(r)?;
-		let byte_size = (len as usize)
-		                .checked_mul(COMPACT_SIGNATURE_SIZE)
-		                .ok_or(DecodeError::BadLengthDescriptor)?;
-		if byte_size > MAX_BUF_SIZE {
-			return Err(DecodeError::BadLengthDescriptor);
+		let num_witnesses = <u16 as Readable>::read(r)? as usize;
+		let mut witnesses = Vec::with_capacity(num_witnesses);
+		for _ in 0..num_witnesses {
+			// Even though the length of each witness can be inferred in its consensus-encoded form,
+			// the spec includes a length prefix so that implementations don't have to deserialize
+			//  each initially. We do that here anyway as in general we'll need to be able to make
+			// assertions on some properties of the witnesses when receiving a message providing a list
+			// of witnesses. We'll just do a sanity check for the lengths and error if there is a mismatch.
+			let witness_len = <u16 as Readable>::read(r)? as usize;
+			let witness = <Witness as Readable>::read(r)?;
+			if witness.serialized_len() != witness_len {
+				return Err(DecodeError::BadLengthDescriptor);
+			}
+			witnesses.push(witness);
 		}
-		let mut ret = Vec::with_capacity(len as usize);
-		for _ in 0..len { ret.push(Readable::read(r)?); }
-		Ok(ret)
+		Ok(witnesses)
 	}
 }
 
@@ -750,6 +936,39 @@ impl Readable for SecretKey {
 	}
 }
 
+#[cfg(taproot)]
+impl Writeable for musig2::types::PublicNonce {
+	fn write<W: Writer>(&self, w: &mut W) -> Result<(), io::Error> {
+		self.serialize().write(w)
+	}
+}
+
+#[cfg(taproot)]
+impl Readable for musig2::types::PublicNonce {
+	fn read<R: Read>(r: &mut R) -> Result<Self, DecodeError> {
+		let buf: [u8; PUBLIC_KEY_SIZE * 2] = Readable::read(r)?;
+		musig2::types::PublicNonce::from_slice(&buf).map_err(|_| DecodeError::InvalidValue)
+	}
+}
+
+#[cfg(taproot)]
+impl Writeable for PartialSignatureWithNonce {
+	fn write<W: Writer>(&self, w: &mut W) -> Result<(), io::Error> {
+		self.0.serialize().write(w)?;
+		self.1.write(w)
+	}
+}
+
+#[cfg(taproot)]
+impl Readable for PartialSignatureWithNonce {
+	fn read<R: Read>(r: &mut R) -> Result<Self, DecodeError> {
+		let partial_signature_buf: [u8; SECRET_KEY_SIZE] = Readable::read(r)?;
+		let partial_signature = musig2::types::PartialSignature::from_slice(&partial_signature_buf).map_err(|_| DecodeError::InvalidValue)?;
+		let public_nonce: musig2::types::PublicNonce = Readable::read(r)?;
+		Ok(PartialSignatureWithNonce(partial_signature, public_nonce))
+	}
+}
+
 impl Writeable for Sha256dHash {
 	fn write<W: Writer>(&self, w: &mut W) -> Result<(), io::Error> {
 		w.write_all(&self[..])
@@ -962,6 +1181,7 @@ macro_rules! impl_consensus_ser {
 }
 impl_consensus_ser!(Transaction);
 impl_consensus_ser!(TxOut);
+impl_consensus_ser!(Witness);
 
 impl<T: Readable> Readable for Mutex<T> {
 	fn read<R: Read>(r: &mut R) -> Result<Self, DecodeError> {
@@ -1005,6 +1225,24 @@ impl<A: Writeable, B: Writeable, C: Writeable> Writeable for (A, B, C) {
 	}
 }
 
+impl<A: Readable, B: Readable, C: Readable, D: Readable> Readable for (A, B, C, D) {
+	fn read<R: Read>(r: &mut R) -> Result<Self, DecodeError> {
+		let a: A = Readable::read(r)?;
+		let b: B = Readable::read(r)?;
+		let c: C = Readable::read(r)?;
+		let d: D = Readable::read(r)?;
+		Ok((a, b, c, d))
+	}
+}
+impl<A: Writeable, B: Writeable, C: Writeable, D: Writeable> Writeable for (A, B, C, D) {
+	fn write<W: Writer>(&self, w: &mut W) -> Result<(), io::Error> {
+		self.0.write(w)?;
+		self.1.write(w)?;
+		self.2.write(w)?;
+		self.3.write(w)
+	}
+}
+
 impl Writeable for () {
 	fn write<W: Writer>(&self, _: &mut W) -> Result<(), io::Error> {
 		Ok(())
@@ -1019,7 +1257,7 @@ impl Readable for () {
 impl Writeable for String {
 	#[inline]
 	fn write<W: Writer>(&self, w: &mut W) -> Result<(), io::Error> {
-		(self.len() as u16).write(w)?;
+		CollectionLength(self.len() as u64).write(w)?;
 		w.write_all(self.as_bytes())
 	}
 }
@@ -1036,7 +1274,9 @@ impl Readable for String {
 /// Only the character set and length will be validated.
 /// The character set consists of ASCII alphanumeric characters, hyphens, and periods.
 /// Its length is guaranteed to be representable by a single byte.
-/// This serialization is used by BOLT 7 hostnames.
+/// This serialization is used by [`BOLT 7`] hostnames.
+///
+/// [`BOLT 7`]: https://github.com/lightning/bolts/blob/master/07-routing-gossip.md
 #[derive(Clone, Debug, PartialEq, Eq)]
 pub struct Hostname(String);
 impl Hostname {
@@ -1101,6 +1341,7 @@ impl Readable for Hostname {
 	}
 }
 
+/// This is not exported to bindings users as `Duration`s are simply mapped as ints.
 impl Writeable for Duration {
 	#[inline]
 	fn write<W: Writer>(&self, w: &mut W) -> Result<(), io::Error> {
@@ -1108,6 +1349,7 @@ impl Writeable for Duration {
 		self.subsec_nanos().write(w)
 	}
 }
+/// This is not exported to bindings users as `Duration`s are simply mapped as ints.
 impl Readable for Duration {
 	#[inline]
 	fn read<R: Read>(r: &mut R) -> Result<Self, DecodeError> {
@@ -1117,9 +1359,66 @@ impl Readable for Duration {
 	}
 }
 
+/// A wrapper for a `Transaction` which can only be constructed with [`TransactionU16LenLimited::new`]
+/// if the `Transaction`'s consensus-serialized length is <= u16::MAX.
+///
+/// Use [`TransactionU16LenLimited::into_transaction`] to convert into the contained `Transaction`.
+#[derive(Clone, Debug, PartialEq, Eq)]
+pub struct TransactionU16LenLimited(Transaction);
+
+impl TransactionU16LenLimited {
+	/// Constructs a new `TransactionU16LenLimited` from a `Transaction` only if it's consensus-
+	/// serialized length is <= u16::MAX.
+	pub fn new(transaction: Transaction) -> Result<Self, ()> {
+		if transaction.serialized_length() > (u16::MAX as usize) {
+			Err(())
+		} else {
+			Ok(Self(transaction))
+		}
+	}
+
+	/// Consumes this `TransactionU16LenLimited` and returns its contained `Transaction`.
+	pub fn into_transaction(self) -> Transaction {
+		self.0
+	}
+}
+
+impl Writeable for TransactionU16LenLimited {
+	fn write<W: Writer>(&self, w: &mut W) -> Result<(), io::Error> {
+		(self.0.serialized_length() as u16).write(w)?;
+		self.0.write(w)
+	}
+}
+
+impl Readable for TransactionU16LenLimited {
+	fn read<R: Read>(r: &mut R) -> Result<Self, DecodeError> {
+		let len = <u16 as Readable>::read(r)?;
+		let mut tx_reader = FixedLengthReader::new(r, len as u64);
+		let tx: Transaction = Readable::read(&mut tx_reader)?;
+		if tx_reader.bytes_remain() {
+			Err(DecodeError::BadLengthDescriptor)
+		} else {
+			Ok(Self(tx))
+		}
+	}
+}
+
+impl Writeable for ClaimId {
+	fn write<W: Writer>(&self, writer: &mut W) -> Result<(), io::Error> {
+		self.0.write(writer)
+	}
+}
+
+impl Readable for ClaimId {
+	fn read<R: io::Read>(reader: &mut R) -> Result<Self, DecodeError> {
+		Ok(Self(Readable::read(reader)?))
+	}
+}
+
 #[cfg(test)]
 mod tests {
 	use core::convert::TryFrom;
+	use bitcoin::secp256k1::ecdsa;
 	use crate::util::ser::{Readable, Hostname, Writeable};
 
 	#[test]
@@ -1141,4 +1440,57 @@ mod tests {
 		hostname.write(&mut buf).unwrap();
 		assert_eq!(Hostname::read(&mut buf.as_slice()).unwrap().as_str(), "test");
 	}
+
+	#[test]
+	/// Taproot will likely fill legacy signature fields with all 0s.
+	/// This test ensures that doing so won't break serialization.
+	fn null_signature_codec() {
+		let buffer = vec![0u8; 64];
+		let mut cursor = crate::io::Cursor::new(buffer.clone());
+		let signature = ecdsa::Signature::read(&mut cursor).unwrap();
+		let serialization = signature.serialize_compact();
+		assert_eq!(buffer, serialization.to_vec())
+	}
+
+	#[test]
+	fn bigsize_encoding_decoding() {
+		let values = vec![0, 252, 253, 65535, 65536, 4294967295, 4294967296, 18446744073709551615];
+		let bytes = vec![
+			"00",
+			"fc",
+			"fd00fd",
+			"fdffff",
+			"fe00010000",
+			"feffffffff",
+			"ff0000000100000000",
+			"ffffffffffffffffff"
+		];
+		for i in 0..=7 {
+			let mut stream = crate::io::Cursor::new(::hex::decode(bytes[i]).unwrap());
+			assert_eq!(super::BigSize::read(&mut stream).unwrap().0, values[i]);
+			let mut stream = super::VecWriter(Vec::new());
+			super::BigSize(values[i]).write(&mut stream).unwrap();
+			assert_eq!(stream.0, ::hex::decode(bytes[i]).unwrap());
+		}
+		let err_bytes = vec![
+			"fd00fc",
+			"fe0000ffff",
+			"ff00000000ffffffff",
+			"fd00",
+			"feffff",
+			"ffffffffff",
+			"fd",
+			"fe",
+			"ff",
+			""
+		];
+		for i in 0..=9 {
+			let mut stream = crate::io::Cursor::new(::hex::decode(err_bytes[i]).unwrap());
+			if i < 3 {
+				assert_eq!(super::BigSize::read(&mut stream).err(), Some(crate::ln::msgs::DecodeError::InvalidValue));
+			} else {
+				assert_eq!(super::BigSize::read(&mut stream).err(), Some(crate::ln::msgs::DecodeError::ShortRead));
+			}
+		}
+	}
 }