WIP: Demonstrate usage of LockTime

Author: tcharding

Cargo.toml

@@ -17,17 +17,18 @@ no-std = ["hashbrown", "bitcoin/no-std"]
 compiler = []
 trace = []
 unstable = []
-use-serde = ["serde", "bitcoin/use-serde"]
+use-serde = ["serde", "bitcoin/serde"]
 rand = ["bitcoin/rand"]
 
 [dependencies]
-bitcoin = { version = "0.28.1", default-features = false }
-serde = { version = "1.0", optional = true }
+bitcoin = { git = "https://github.com/tcharding/rust-bitcoin", default-features = false, branch = "05-17-timelock" }
+serde = { version = "1.0", optional = true}
 hashbrown = { version = "0.11", optional = true }
 
 [dev-dependencies]
 bitcoind = {version = "0.26.1", features=["22_0"]}
 actual-rand = { package = "rand", version = "0.8.4"}
+bitcoin = { git = "https://github.com/tcharding/rust-bitcoin", branch = "05-17-timelock", features = ["rand"] }
 
 [[example]]
 name = "htlc"

examples/sign_multisig.rs

@@ -18,7 +18,7 @@ use std::collections::HashMap;
 use std::str::FromStr;
 
 use bitcoin::blockdata::witness::Witness;
-use bitcoin::secp256k1;
+use bitcoin::{secp256k1, LockTime};
 
 fn main() {
     let mut tx = spending_transaction();
@@ -91,7 +91,7 @@ fn main() {
 fn spending_transaction() -> bitcoin::Transaction {
     bitcoin::Transaction {
         version: 2,
-        lock_time: 0,
+        lock_time: LockTime::from(0),
         input: vec![bitcoin::TxIn {
             previous_output: Default::default(),
             script_sig: bitcoin::Script::new(),

examples/verify_tx.rs

@@ -16,6 +16,7 @@
 
 use std::str::FromStr;
 
+use bitcoin::LockTime;
 use bitcoin::consensus::Decodable;
 use bitcoin::secp256k1::{self, Secp256k1};
 use bitcoin::util::sighash;
@@ -34,7 +35,7 @@ fn main() {
         &tx.input[0].script_sig,
         &tx.input[0].witness,
         0,
-        0,
+        LockTime::from(0),
     )
     .unwrap();
 

src/descriptor/tr.rs

@@ -262,6 +262,7 @@ impl<Pk: MiniscriptKey> Tr<Pk> {
                     TaprootBuilderError::EmptyTree => {
                         unreachable!("Taptree is a well formed tree with atleast 1 element")
                     }
+                    _ => panic!("Unknown error, non_exhaustive catch all"),
                 },
             }
         };

src/interpreter/error.rs

@@ -29,6 +29,8 @@ use crate::prelude::*;
 pub enum Error {
     /// Could not satisfy, absolute locktime not met
     AbsoluteLocktimeNotMet(u32),
+    /// Could not satisfy, lock time values are different units
+    AbsoluteLocktimeComparisonInvalid(u32, u32),
     /// Cannot Infer a taproot descriptor
     /// Key spends cannot infer the internal key of the descriptor
     /// Inferring script spends is possible, but is hidden nodes are currently
@@ -191,6 +193,7 @@ impl fmt::Display for Error {
             Error::VerifyFailed => {
                 f.write_str("Expected Satisfied Boolean at stack top for VERIFY")
             }
+            _ => f.write_str("Unknown error, non_exhaustive catch all"),
         }
     }
 }
@@ -238,6 +241,7 @@ impl error::Error for Error {
             Secp(e) => Some(e),
             SchnorrSig(e) => Some(e),
             SighashError(e) => Some(e),
+            _ => None           // non_exhaustive catch all.
         }
     }
 }

src/interpreter/mod.rs

@@ -25,7 +25,7 @@ use core::str::FromStr;
 use bitcoin::blockdata::witness::Witness;
 use bitcoin::hashes::{hash160, ripemd160, sha256, sha256d};
 use bitcoin::util::{sighash, taproot};
-use bitcoin::{self, secp256k1, TxOut};
+use bitcoin::{self, secp256k1, TxOut, LockTime};
 
 use crate::miniscript::context::NoChecks;
 use crate::miniscript::ScriptContext;
@@ -49,7 +49,7 @@ pub struct Interpreter<'txin> {
     /// is the leaf script; for key-spends it is `None`.
     script_code: Option<bitcoin::Script>,
     age: u32,
-    height: u32,
+    lock_time: LockTime,
 }
 
 // A type representing functions for checking signatures that accept both
@@ -170,15 +170,15 @@ impl<'txin> Interpreter<'txin> {
         script_sig: &'txin bitcoin::Script,
         witness: &'txin Witness,
         age: u32,               // CSV, relative lock time.
-        height: u32,            // CLTV, absolute lock time.
+        lock_time: LockTime,    // CLTV, absolute lock time.
     ) -> Result<Self, Error> {
         let (inner, stack, script_code) = inner::from_txdata(spk, script_sig, witness)?;
         Ok(Interpreter {
             inner,
             stack,
             script_code,
             age,
-            height,
+            lock_time,
         })
     }
 
@@ -209,7 +209,7 @@ impl<'txin> Interpreter<'txin> {
             // call interpreter.iter() without mutating interpreter
             stack: self.stack.clone(),
             age: self.age,
-            height: self.height,
+            lock_time: self.lock_time,
             has_errored: false,
         }
     }
@@ -492,7 +492,7 @@ pub enum SatisfiedConstraint {
     ///Absolute Timelock for CLTV.
     AbsoluteTimelock {
         /// The value of Absolute timelock
-        time: u32,
+        n: LockTime,
     },
 }
 
@@ -528,7 +528,7 @@ pub struct Iter<'intp, 'txin: 'intp> {
     state: Vec<NodeEvaluationState<'intp>>,
     stack: Stack<'txin>,
     age: u32,
-    height: u32,
+    lock_time: LockTime,
     has_errored: bool,
 }
 
@@ -605,7 +605,7 @@ where
                 Terminal::After(ref n) => {
                     debug_assert_eq!(node_state.n_evaluated, 0);
                     debug_assert_eq!(node_state.n_satisfied, 0);
-                    let res = self.stack.evaluate_after(n, self.height);
+                    let res = self.stack.evaluate_after(n, self.lock_time);
                     if res.is_some() {
                         return res;
                     }
@@ -1131,7 +1131,7 @@ mod tests {
                     n_satisfied: 0,
                 }],
                 age: 1002,
-                height: 1002,
+                lock_time: LockTime::from(1002),
                 has_errored: false,
             }
         }
@@ -1197,7 +1197,7 @@ mod tests {
         let after_satisfied: Result<Vec<SatisfiedConstraint>, Error> = constraints.collect();
         assert_eq!(
             after_satisfied.unwrap(),
-            vec![SatisfiedConstraint::AbsoluteTimelock { time: 1000 }]
+            vec![SatisfiedConstraint::AbsoluteTimelock { time: LockTime::from(1000) }]
         );
 
         //Check Older

src/interpreter/stack.rs

@@ -17,6 +17,7 @@
 use bitcoin;
 use bitcoin::blockdata::{opcodes, script};
 use bitcoin::hashes::{hash160, ripemd160, sha256, sha256d, Hash};
+use bitcoin::{locktime, LockTime};
 
 use super::error::PkEvalErrInner;
 use super::{
@@ -231,14 +232,16 @@ impl<'txin> Stack<'txin> {
     /// booleans
     pub(super) fn evaluate_after(
         &mut self,
-        n: &u32,
-        lock_time: u32,
+        n: &LockTime,
+        lock_time: LockTime,
     ) -> Option<Result<SatisfiedConstraint, Error>> {
-        if lock_time >= *n {
-            self.push(Element::Satisfied);
-            Some(Ok(SatisfiedConstraint::AbsoluteTimelock { time: *n }))
-        } else {
-            Some(Err(Error::AbsoluteLocktimeNotMet(*n)))
+        match locktime::is_satisfied(*n, lock_time) {
+            Ok(true) => {
+                self.push(Element::Satisfied);
+                Some(Ok(SatisfiedConstraint::AbsoluteTimelock { n: *n }))
+            },
+            Ok(false) => Some(Err(Error::AbsoluteLocktimeNotMet(n.to_u32()))),
+            Err(_) => Some(Err(Error::AbsoluteLocktimeComparisonInvalid(n.to_u32(), lock_time.to_u32()))),
         }
     }
 

src/lib.rs

@@ -116,7 +116,6 @@ pub mod interpreter;
 pub mod miniscript;
 pub mod policy;
 pub mod psbt;
-pub mod timelock;
 
 mod util;
 

src/miniscript/astelem.rs

@@ -22,6 +22,7 @@
 use core::str::FromStr;
 use core::{fmt, str};
 
+use bitcoin::LockTime;
 use bitcoin::blockdata::{opcodes, script};
 use bitcoin::hashes::hex::FromHex;
 use bitcoin::hashes::{hash160, ripemd160, sha256, sha256d, Hash};
@@ -492,7 +493,7 @@ where
                 expression::terminal(&top.args[0], |x| Pk::Hash::from_str(x).map(Terminal::PkH))
             }
             ("after", 1) => expression::terminal(&top.args[0], |x| {
-                expression::parse_num(x).map(Terminal::After)
+                expression::parse_num(x).map(|x| Terminal::After(LockTime::from(x)))
             }),
             ("older", 1) => expression::terminal(&top.args[0], |x| {
                 expression::parse_num(x).map(Terminal::Older)
@@ -654,7 +655,7 @@ impl<Pk: MiniscriptKey, Ctx: ScriptContext> Terminal<Pk, Ctx> {
                 .push_slice(&Pk::hash_to_hash160(hash)[..])
                 .push_opcode(opcodes::all::OP_EQUALVERIFY),
             Terminal::After(t) => builder
-                .push_int(t as i64)
+                .push_int(t.to_u32() as i64)
                 .push_opcode(opcodes::all::OP_CLTV),
             Terminal::Older(t) => builder.push_int(t as i64).push_opcode(opcodes::all::OP_CSV),
             Terminal::Sha256(h) => builder
@@ -789,7 +790,7 @@ impl<Pk: MiniscriptKey, Ctx: ScriptContext> Terminal<Pk, Ctx> {
         match *self {
             Terminal::PkK(ref pk) => Ctx::pk_len(pk),
             Terminal::PkH(..) => 24,
-            Terminal::After(n) => script_num_size(n as usize) + 1,
+            Terminal::After(n) => script_num_size(n.to_u32() as usize) + 1,
             Terminal::Older(n) => script_num_size(n as usize) + 1,
             Terminal::Sha256(..) => 33 + 6,
             Terminal::Hash256(..) => 33 + 6,

src/miniscript/decode.rs

@@ -28,6 +28,7 @@ use sync::Arc;
 
 use crate::miniscript::lex::{Token as Tk, TokenIter};
 use crate::miniscript::limits::MAX_PUBKEYS_PER_MULTISIG;
+use crate::bitcoin::locktime::LockTime;
 use crate::miniscript::types::extra_props::ExtData;
 use crate::miniscript::types::{Property, Type};
 use crate::miniscript::ScriptContext;
@@ -137,7 +138,7 @@ pub enum Terminal<Pk: MiniscriptKey, Ctx: ScriptContext> {
     PkH(Pk::Hash),
     // timelocks
     /// `n CHECKLOCKTIMEVERIFY`
-    After(u32),
+    After(LockTime),
     /// `n CHECKSEQUENCEVERIFY`
     Older(u32),
     // hashlocks
@@ -392,7 +393,7 @@ pub fn parse<Ctx: ScriptContext>(
                     Tk::CheckSequenceVerify, Tk::Num(n)
                         => term.reduce0(Terminal::Older(n))?,
                     Tk::CheckLockTimeVerify, Tk::Num(n)
-                        => term.reduce0(Terminal::After(n))?,
+                        => term.reduce0(Terminal::After(LockTime::from(n)))?,
                     // hashlocks
                     Tk::Equal => match_token!(
                         tokens,

src/miniscript/mod.rs

@@ -981,7 +981,7 @@ mod tests {
         ));
         assert_eq!(
             ms.unwrap_err().to_string(),
-            "unexpected «Key hex decoding error: bad hex string length 64 (expected 66)»"
+            "unexpected «key hex decoding error»"
         );
         Tapscript::from_str_insane(&format!(
             "pk(2788ee41e76f4f3af603da5bc8fa22997bc0344bb0f95666ba6aaff0242baa99)"

src/miniscript/satisfy.rs

@@ -20,14 +20,14 @@
 
 use core::{cmp, i64, mem};
 
-use bitcoin;
+use bitcoin::LockTime;
 use bitcoin::hashes::{hash160, ripemd160, sha256, sha256d};
 use bitcoin::secp256k1::XOnlyPublicKey;
 use bitcoin::util::taproot::{ControlBlock, LeafVersion, TapLeafHash};
 use sync::Arc;
 
 use crate::miniscript::limits::{
-    LOCKTIME_THRESHOLD, SEQUENCE_LOCKTIME_DISABLE_FLAG, SEQUENCE_LOCKTIME_TYPE_FLAG,
+    SEQUENCE_LOCKTIME_DISABLE_FLAG, SEQUENCE_LOCKTIME_TYPE_FLAG,
 };
 use crate::prelude::*;
 use crate::util::witness_size;
@@ -115,7 +115,7 @@ pub trait Satisfier<Pk: MiniscriptKey + ToPublicKey> {
     }
 
     /// Assert whether a absolute locktime is satisfied
-    fn check_after(&self, _: u32) -> bool {
+    fn check_after(&self, _: LockTime) -> bool {
         false
     }
 }
@@ -148,21 +148,6 @@ impl<Pk: MiniscriptKey + ToPublicKey> Satisfier<Pk> for Older {
     }
 }
 
-/// Newtype around `u32` which implements `Satisfier` using `n` as an
-/// absolute locktime
-pub struct After(pub u32);
-
-impl<Pk: MiniscriptKey + ToPublicKey> Satisfier<Pk> for After {
-    fn check_after(&self, n: u32) -> bool {
-        // if n > self.0; we will be returning false anyways
-        if n < LOCKTIME_THRESHOLD && self.0 >= LOCKTIME_THRESHOLD {
-            false
-        } else {
-            n <= self.0
-        }
-    }
-}
-
 impl<Pk: MiniscriptKey + ToPublicKey> Satisfier<Pk> for HashMap<Pk, bitcoin::EcdsaSig> {
     fn lookup_ecdsa_sig(&self, key: &Pk) -> Option<bitcoin::EcdsaSig> {
         self.get(key).copied()
@@ -277,7 +262,7 @@ impl<'a, Pk: MiniscriptKey + ToPublicKey, S: Satisfier<Pk>> Satisfier<Pk> for &'
         (**self).check_older(t)
     }
 
-    fn check_after(&self, t: u32) -> bool {
+    fn check_after(&self, t: LockTime) -> bool {
         (**self).check_after(t)
     }
 }
@@ -339,7 +324,7 @@ impl<'a, Pk: MiniscriptKey + ToPublicKey, S: Satisfier<Pk>> Satisfier<Pk> for &'
         (**self).check_older(t)
     }
 
-    fn check_after(&self, t: u32) -> bool {
+    fn check_after(&self, t: LockTime) -> bool {
         (**self).check_after(t)
     }
 }
@@ -483,7 +468,7 @@ macro_rules! impl_tuple_satisfier {
                 false
             }
 
-            fn check_after(&self, n: u32) -> bool {
+            fn check_after(&self, n: LockTime) -> bool {
                 let &($(ref $ty,)*) = self;
                 $(
                     if $ty.check_after(n) {