Support all shutdown scripts defined in BOLT 2

[rust-lightning] / lightning / src / ln / script.rs

diff --git a/lightning/src/ln/script.rs b/lightning/src/ln/script.rs
index 69b09e958d9f08507529f4da890710b585a77d97..a01866de679e8762bce76b9fe3a7df4fe666b301 100644 (file)
--- a/lightning/src/ln/script.rs
+++ b/lightning/src/ln/script.rs
@@ -8,19 +8,24 @@ use bitcoin::hash_types::{PubkeyHash, ScriptHash, WPubkeyHash, WScriptHash};
 use bitcoin::secp256k1::key::PublicKey;
 
 use ln::features::InitFeatures;
+use ln::msgs::DecodeError;
+use util::ser::{Readable, Writeable, Writer};
 
-use std::convert::From;
 use std::convert::TryFrom;
+use std::io::Read;
+use core::num::NonZeroU8;
 
 /// A script pubkey for shutting down a channel as defined by [BOLT #2].
 ///
 /// [BOLT #2]: https://github.com/lightningnetwork/lightning-rfc/blob/master/02-peer-protocol.md
+#[derive(Clone)]
 pub struct ShutdownScript(ShutdownScriptImpl);
 
 /// An error occurring when converting from [`Script`] to [`ShutdownScript`].
 #[derive(Debug)]
 pub struct InvalidShutdownScript(Script);
 
+#[derive(Clone)]
 enum ShutdownScriptImpl {
        /// [`PublicKey`] used to form a P2WPKH script pubkey. Used to support backward-compatible
        /// serialization.
@@ -30,7 +35,33 @@ enum ShutdownScriptImpl {
        Bolt2(Script),
 }
 
+impl Writeable for ShutdownScript {
+       fn write<W: Writer>(&self, w: &mut W) -> Result<(), ::std::io::Error> {
+               self.0.write(w)
+       }
+
+       fn serialized_length(&self) -> usize {
+               self.0.serialized_length()
+       }
+}
+
+impl Readable for ShutdownScript {
+       fn read<R: Read>(r: &mut R) -> Result<Self, DecodeError> {
+               Ok(ShutdownScript(ShutdownScriptImpl::read(r)?))
+       }
+}
+
+impl_writeable_tlv_based_enum!(ShutdownScriptImpl, ;
+       (0, Legacy),
+       (1, Bolt2),
+);
+
 impl ShutdownScript {
+       /// Generates a P2WPKH script pubkey from the given [`PublicKey`].
+       pub(crate) fn new_p2wpkh_from_pubkey(pubkey: PublicKey) -> Self {
+               Self(ShutdownScriptImpl::Legacy(pubkey))
+       }
+
        /// Generates a P2PKH script pubkey from the given [`PubkeyHash`].
        pub fn new_p2pkh(pubkey_hash: &PubkeyHash) -> Self {
                Self(ShutdownScriptImpl::Bolt2(Script::new_p2pkh(pubkey_hash)))
@@ -56,7 +87,8 @@ impl ShutdownScript {
        /// # Panics
        ///
        /// This function may panic if given a segwit program with an invalid length.
-       pub fn new_witness_program(version: u5, program: &[u8]) -> Self {
+       pub fn new_witness_program(version: NonZeroU8, program: &[u8]) -> Self {
+               let version = u5::try_from_u8(version.get()).expect("Invalid segwit version");
                let script = Script::new_witness_program(version, program);
                Self::try_from(script).expect("Invalid segwit program")
        }
@@ -65,11 +97,13 @@ impl ShutdownScript {
        pub fn into_inner(self) -> Script {
                self.into()
        }
-}
 
-impl From<PublicKey> for ShutdownScript {
-       fn from(pubkey: PublicKey) -> Self {
-               Self(ShutdownScriptImpl::Legacy(pubkey))
+       /// Returns the [`PublicKey`] used for a P2WPKH shutdown script if constructed directly from it.
+       pub fn as_legacy_pubkey(&self) -> Option<&PublicKey> {
+               match &self.0 {
+                       ShutdownScriptImpl::Legacy(pubkey) => Some(pubkey),
+                       ShutdownScriptImpl::Bolt2(_) => None,
+               }
        }
 }
 
@@ -138,7 +172,7 @@ mod shutdown_script_tests {
                let pubkey_hash = pubkey.wpubkey_hash().unwrap();
                let p2wpkh_script = Script::new_v0_wpkh(&pubkey_hash);
 
-               let shutdown_script = ShutdownScript::from(pubkey.key);
+               let shutdown_script = ShutdownScript::new_p2wpkh_from_pubkey(pubkey.key);
                assert_eq!(shutdown_script.into_inner(), p2wpkh_script);
        }