use bitcoin::blockdata::opcodes::all::OP_PUSHBYTES_0 as SEGWIT_V0;
use bitcoin::blockdata::script::{Script, ScriptBuf};
use bitcoin::hashes::Hash;
use bitcoin::hash_types::{WPubkeyHash, WScriptHash};
use bitcoin::secp256k1::PublicKey;
use bitcoin::address::WitnessProgram;
use crate::ln::channelmanager;
use crate::ln::features::InitFeatures;
use crate::ln::msgs::DecodeError;
use crate::util::ser::{Readable, Writeable, Writer};
use crate::io;
#[allow(unused_imports)]
use crate::prelude::*;
#[derive(Clone, PartialEq, Eq)]
pub struct ShutdownScript(ShutdownScriptImpl);
#[derive(Clone, Debug)]
pub struct InvalidShutdownScript {
pub script: ScriptBuf
}
#[derive(Clone, PartialEq, Eq)]
enum ShutdownScriptImpl {
Legacy(PublicKey),
Bolt2(ScriptBuf),
}
impl Writeable for ShutdownScript {
fn write<W: Writer>(&self, w: &mut W) -> Result<(), io::Error> {
self.0.write(w)
}
}
impl Readable for ShutdownScript {
fn read<R: io::Read>(r: &mut R) -> Result<Self, DecodeError> {
Ok(ShutdownScript(ShutdownScriptImpl::read(r)?))
}
}
impl_writeable_tlv_based_enum!(ShutdownScriptImpl, ;
(0, Legacy),
(1, Bolt2),
);
impl ShutdownScript {
pub(crate) fn new_p2wpkh_from_pubkey(pubkey: PublicKey) -> Self {
Self(ShutdownScriptImpl::Legacy(pubkey))
}
pub fn new_p2wpkh(pubkey_hash: &WPubkeyHash) -> Self {
Self(ShutdownScriptImpl::Bolt2(ScriptBuf::new_v0_p2wpkh(pubkey_hash)))
}
pub fn new_p2wsh(script_hash: &WScriptHash) -> Self {
Self(ShutdownScriptImpl::Bolt2(ScriptBuf::new_v0_p2wsh(script_hash)))
}
pub fn new_witness_program(witness_program: &WitnessProgram) -> Result<Self, InvalidShutdownScript> {
Self::try_from(ScriptBuf::new_witness_program(witness_program))
}
pub fn into_inner(self) -> ScriptBuf {
self.into()
}
pub fn as_legacy_pubkey(&self) -> Option<&PublicKey> {
match &self.0 {
ShutdownScriptImpl::Legacy(pubkey) => Some(pubkey),
ShutdownScriptImpl::Bolt2(_) => None,
}
}
pub fn is_compatible(&self, features: &InitFeatures) -> bool {
match &self.0 {
ShutdownScriptImpl::Legacy(_) => true,
ShutdownScriptImpl::Bolt2(script) => is_bolt2_compliant(script, features),
}
}
}
pub(crate) fn is_bolt2_compliant(script: &Script, features: &InitFeatures) -> bool {
if script.is_p2pkh() || script.is_p2sh() || script.is_v0_p2wpkh() || script.is_v0_p2wsh() {
true
} else if features.supports_shutdown_anysegwit() {
script.is_witness_program() && script.as_bytes()[0] != SEGWIT_V0.to_u8()
} else {
false
}
}
impl TryFrom<ScriptBuf> for ShutdownScript {
type Error = InvalidShutdownScript;
fn try_from(script: ScriptBuf) -> Result<Self, Self::Error> {
Self::try_from((script, &channelmanager::provided_init_features(&crate::util::config::UserConfig::default())))
}
}
impl TryFrom<(ScriptBuf, &InitFeatures)> for ShutdownScript {
type Error = InvalidShutdownScript;
fn try_from((script, features): (ScriptBuf, &InitFeatures)) -> Result<Self, Self::Error> {
if is_bolt2_compliant(&script, features) && script.is_witness_program() {
Ok(Self(ShutdownScriptImpl::Bolt2(script)))
} else {
Err(InvalidShutdownScript { script })
}
}
}
impl Into<ScriptBuf> for ShutdownScript {
fn into(self) -> ScriptBuf {
match self.0 {
ShutdownScriptImpl::Legacy(pubkey) =>
ScriptBuf::new_v0_p2wpkh(&WPubkeyHash::hash(&pubkey.serialize())),
ShutdownScriptImpl::Bolt2(script_pubkey) => script_pubkey,
}
}
}
impl core::fmt::Display for ShutdownScript{
fn fmt(&self, f: &mut core::fmt::Formatter) -> core::fmt::Result {
match &self.0 {
ShutdownScriptImpl::Legacy(_) => self.clone().into_inner().fmt(f),
ShutdownScriptImpl::Bolt2(script) => script.fmt(f),
}
}
}
#[cfg(test)]
mod shutdown_script_tests {
use super::ShutdownScript;
use bitcoin::address::{WitnessProgram, WitnessVersion};
use bitcoin::blockdata::opcodes;
use bitcoin::blockdata::script::{Builder, ScriptBuf};
use bitcoin::secp256k1::Secp256k1;
use bitcoin::secp256k1::{PublicKey, SecretKey};
use crate::ln::features::InitFeatures;
use crate::prelude::*;
fn pubkey() -> bitcoin::key::PublicKey {
let secp_ctx = Secp256k1::signing_only();
let secret_key = SecretKey::from_slice(&[0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1]).unwrap();
bitcoin::key::PublicKey::new(PublicKey::from_secret_key(&secp_ctx, &secret_key))
}
fn redeem_script() -> ScriptBuf {
let pubkey = pubkey();
Builder::new()
.push_opcode(opcodes::all::OP_PUSHNUM_2)
.push_key(&pubkey)
.push_key(&pubkey)
.push_opcode(opcodes::all::OP_PUSHNUM_2)
.push_opcode(opcodes::all::OP_CHECKMULTISIG)
.into_script()
}
fn any_segwit_features() -> InitFeatures {
let mut features = InitFeatures::empty();
features.set_shutdown_any_segwit_optional();
features
}
#[test]
fn generates_p2wpkh_from_pubkey() {
let pubkey = pubkey();
let pubkey_hash = pubkey.wpubkey_hash().unwrap();
let p2wpkh_script = ScriptBuf::new_v0_p2wpkh(&pubkey_hash);
let shutdown_script = ShutdownScript::new_p2wpkh_from_pubkey(pubkey.inner);
assert!(shutdown_script.is_compatible(&any_segwit_features()));
assert!(shutdown_script.is_compatible(&InitFeatures::empty()));
assert_eq!(shutdown_script.into_inner(), p2wpkh_script);
}
#[test]
fn generates_p2wpkh_from_pubkey_hash() {
let pubkey_hash = pubkey().wpubkey_hash().unwrap();
let p2wpkh_script = ScriptBuf::new_v0_p2wpkh(&pubkey_hash);
let shutdown_script = ShutdownScript::new_p2wpkh(&pubkey_hash);
assert!(shutdown_script.is_compatible(&any_segwit_features()));
assert!(shutdown_script.is_compatible(&InitFeatures::empty()));
assert_eq!(shutdown_script.into_inner(), p2wpkh_script);
assert!(ShutdownScript::try_from(p2wpkh_script).is_ok());
}
#[test]
fn generates_p2wsh_from_script_hash() {
let script_hash = redeem_script().wscript_hash();
let p2wsh_script = ScriptBuf::new_v0_p2wsh(&script_hash);
let shutdown_script = ShutdownScript::new_p2wsh(&script_hash);
assert!(shutdown_script.is_compatible(&any_segwit_features()));
assert!(shutdown_script.is_compatible(&InitFeatures::empty()));
assert_eq!(shutdown_script.into_inner(), p2wsh_script);
assert!(ShutdownScript::try_from(p2wsh_script).is_ok());
}
#[test]
fn generates_segwit_from_non_v0_witness_program() {
let witness_program = WitnessProgram::new(WitnessVersion::V16, &[0; 40]).unwrap();
let script = ScriptBuf::new_witness_program(&witness_program);
let shutdown_script = ShutdownScript::new_witness_program(&witness_program).unwrap();
assert!(shutdown_script.is_compatible(&any_segwit_features()));
assert!(!shutdown_script.is_compatible(&InitFeatures::empty()));
assert_eq!(shutdown_script.into_inner(), script);
}
#[test]
fn fails_from_unsupported_script() {
let op_return = ScriptBuf::new_op_return(&[0; 42]);
assert!(ShutdownScript::try_from(op_return).is_err());
}
}