Use new bitcoin::timelock module

Use the new timelock module (open PR) from `rust-bitcoin`.

This patch is an example of consuming the new timelock API.

Author: tcharding

Cargo.toml

@@ -19,7 +19,9 @@ use-serde = ["serde", "bitcoin/use-serde"]
 rand = ["bitcoin/rand"]
 
 [dependencies]
-bitcoin = "0.28.0"
+# bitcoin = "0.28.0"
+# TODO: Use github branch before pushing.
+bitcoin = { path = "../rust-bitcoin" }
 serde = { version = "1.0", optional = true}
 
 [[example]]

src/interpreter/error.rs

@@ -16,6 +16,7 @@ use std::{error, fmt};
 
 use bitcoin::hashes::hash160;
 use bitcoin::hashes::hex::ToHex;
+use bitcoin::timelock;
 use bitcoin::util::taproot;
 use bitcoin::{self, secp256k1};
 
@@ -25,7 +26,7 @@ use super::BitcoinKey;
 #[derive(Debug)]
 pub enum Error {
     /// Could not satisfy, absolute locktime not met
-    AbsoluteLocktimeNotMet(u32),
+    AbsoluteLocktimeNotMet(timelock::Abs),
     /// 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
@@ -90,7 +91,7 @@ pub enum Error {
     /// Parse Error while parsing a `stack::Element::Push` as a XOnlyPublicKey (32 bytes)
     XOnlyPublicKeyParseError,
     /// Could not satisfy, relative locktime not met
-    RelativeLocktimeNotMet(u32),
+    RelativeLocktimeNotMet(timelock::Rel),
     /// Forward-secp related errors
     Secp(secp256k1::Error),
     /// Miniscript requires the entire top level script to be satisfied.
@@ -101,6 +102,8 @@ pub enum Error {
     SighashError(bitcoin::util::sighash::Error),
     /// Taproot Annex Unsupported
     TapAnnexUnsupported,
+    /// Invalid comparison of timelocks.
+    TimelockComparisonInvalid(timelock::Error),
     /// An uncompressed public key was encountered in a context where it is
     /// disallowed (e.g. in a Segwit script or p2wpkh output)
     UncompressedPubkey,
@@ -196,8 +199,9 @@ impl fmt::Display for Error {
             Error::AbsoluteLocktimeNotMet(n) => write!(
                 f,
                 "required absolute locktime CLTV of {} blocks, not met",
-                n
+                n,
             ),
+            Error::TimelockComparisonInvalid(e) => write!(f, "timelock comparison error: {:?}", e),
             Error::CannotInferTrDescriptors => write!(f, "Cannot infer taproot descriptors"),
             Error::ControlBlockParse(ref e) => write!(f, "Control block parse error {}", e),
             Error::ControlBlockVerificationError => {

src/interpreter/mod.rs

@@ -25,6 +25,7 @@ use std::str::FromStr;
 
 use bitcoin::blockdata::witness::Witness;
 use bitcoin::hashes::{hash160, ripemd160, sha256, sha256d};
+use bitcoin::timelock;
 use bitcoin::util::{sighash, taproot};
 use bitcoin::{self, secp256k1, TxOut};
 
@@ -486,13 +487,13 @@ pub enum SatisfiedConstraint {
     },
     ///Relative Timelock for CSV.
     RelativeTimelock {
-        /// The value of RelativeTimelock
-        time: u32,
+        /// The relative timelock.
+        time: timelock::Rel,
     },
     ///Absolute Timelock for CLTV.
     AbsoluteTimelock {
-        /// The value of Absolute timelock
-        time: u32,
+        /// The absolute timelock.
+        time: timelock::Abs,
     },
 }
 
@@ -1197,7 +1198,7 @@ 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: 1000.into() }]
         );
 
         //Check Older
@@ -1207,7 +1208,7 @@ mod tests {
         let older_satisfied: Result<Vec<SatisfiedConstraint>, Error> = constraints.collect();
         assert_eq!(
             older_satisfied.unwrap(),
-            vec![SatisfiedConstraint::RelativeTimelock { time: 1000 }]
+            vec![SatisfiedConstraint::RelativeTimelock { time: 1000.into() }],
         );
 
         //Check Sha256

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::timelock;
 
 use super::error::PkEvalErrInner;
 use super::{
@@ -230,14 +231,16 @@ impl<'txin> Stack<'txin> {
     /// booleans
     pub(super) fn evaluate_after(
         &mut self,
-        n: &u32,
+        n: &timelock::Abs,
         age: u32,
     ) -> Option<Result<SatisfiedConstraint, Error>> {
-        if age >= *n {
-            self.push(Element::Satisfied);
-            Some(Ok(SatisfiedConstraint::AbsoluteTimelock { time: *n }))
-        } else {
-            Some(Err(Error::AbsoluteLocktimeNotMet(*n)))
+        match n.is_expired(age) {
+            Ok(true) => {
+                self.push(Element::Satisfied);
+                Some(Ok(SatisfiedConstraint::AbsoluteTimelock { time: *n }))
+            }
+            Ok(false) => Some(Err(Error::AbsoluteLocktimeNotMet(*n))),
+            Err(e) => Some(Err(Error::TimelockComparisonInvalid(e))),
         }
     }
 
@@ -249,14 +252,16 @@ impl<'txin> Stack<'txin> {
     /// booleans
     pub(super) fn evaluate_older(
         &mut self,
-        n: &u32,
+        n: &timelock::Rel,
         height: u32,
     ) -> Option<Result<SatisfiedConstraint, Error>> {
-        if height >= *n {
-            self.push(Element::Satisfied);
-            Some(Ok(SatisfiedConstraint::RelativeTimelock { time: *n }))
-        } else {
-            Some(Err(Error::RelativeLocktimeNotMet(*n)))
+        match n.is_expired(height) {
+            Ok(true) => {
+                self.push(Element::Satisfied);
+                Some(Ok(SatisfiedConstraint::RelativeTimelock { time: *n }))
+            }
+            Ok(false) => Some(Err(Error::RelativeLocktimeNotMet(*n))),
+            Err(e) => Some(Err(Error::TimelockComparisonInvalid(e))),
         }
     }
 

src/miniscript/astelem.rs

@@ -491,10 +491,10 @@ 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(x.into()))
             }),
             ("older", 1) => expression::terminal(&top.args[0], |x| {
-                expression::parse_num(x).map(Terminal::Older)
+                expression::parse_num(x).map(|x| Terminal::Older(x.into()))
             }),
             ("sha256", 1) => expression::terminal(&top.args[0], |x| {
                 sha256::Hash::from_hex(x).map(Terminal::Sha256)
@@ -653,9 +653,11 @@ 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::Older(t) => builder
+                .push_int(t.to_u32() as i64)
+                .push_opcode(opcodes::all::OP_CSV),
             Terminal::Sha256(h) => builder
                 .push_opcode(opcodes::all::OP_SIZE)
                 .push_int(32)
@@ -788,8 +790,8 @@ 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::Older(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.to_u32() as usize) + 1,
             Terminal::Sha256(..) => 33 + 6,
             Terminal::Hash256(..) => 33 + 6,
             Terminal::Ripemd160(..) => 21 + 6,

src/miniscript/decode.rs

@@ -23,6 +23,7 @@ use std::{error, fmt};
 
 use bitcoin::blockdata::constants::MAX_BLOCK_WEIGHT;
 use bitcoin::hashes::{hash160, ripemd160, sha256, sha256d, Hash};
+use bitcoin::timelock;
 
 use crate::miniscript::lex::{Token as Tk, TokenIter};
 use crate::miniscript::limits::MAX_PUBKEYS_PER_MULTISIG;
@@ -133,9 +134,9 @@ pub enum Terminal<Pk: MiniscriptKey, Ctx: ScriptContext> {
     PkH(Pk::Hash),
     // timelocks
     /// `n CHECKLOCKTIMEVERIFY`
-    After(u32),
+    After(timelock::Abs),
     /// `n CHECKSEQUENCEVERIFY`
-    Older(u32),
+    Older(timelock::Rel),
     // hashlocks
     /// `SIZE 32 EQUALVERIFY SHA256 <hash> EQUAL`
     Sha256(sha256::Hash),
@@ -386,9 +387,9 @@ pub fn parse<Ctx: ScriptContext>(
                     },
                     // timelocks
                     Tk::CheckSequenceVerify, Tk::Num(n)
-                        => term.reduce0(Terminal::Older(n))?,
+                        => term.reduce0(Terminal::Older(n.into()))?,
                     Tk::CheckLockTimeVerify, Tk::Num(n)
-                        => term.reduce0(Terminal::After(n))?,
+                        => term.reduce0(Terminal::After(n.into()))?,
                     // hashlocks
                     Tk::Equal => match_token!(
                         tokens,

src/miniscript/limits.rs

@@ -14,26 +14,6 @@ pub const MAX_SCRIPT_SIZE: usize = 10_000;
 /// Maximum script size allowed by standardness rules
 // https://github.com/bitcoin/bitcoin/blob/283a73d7eaea2907a6f7f800f529a0d6db53d7a6/src/policy/policy.h#L44
 pub const MAX_STANDARD_P2WSH_SCRIPT_SIZE: usize = 3600;
-/// The Threshold for deciding whether `nLockTime` is interpreted as
-/// time or height.
-// https://github.com/bitcoin/bitcoin/blob/9ccaee1d5e2e4b79b0a7c29aadb41b97e4741332/src/script/script.h#L39
-pub const LOCKTIME_THRESHOLD: u32 = 500_000_000;
-
-/// Bit flag for deciding whether sequence number is
-/// interpreted as height or time
-/* If nSequence encodes a relative lock-time and this flag
- * is set, the relative lock-time has units of 512 seconds,
- * otherwise it specifies blocks with a granularity of 1. */
-// https://github.com/bitcoin/bips/blob/master/bip-0112.mediawiki
-pub const SEQUENCE_LOCKTIME_TYPE_FLAG: u32 = 1 << 22;
-
-/// Disable flag for sequence locktime
-/* Below flags apply in the context of BIP 68*/
-/* If this flag set, nSequence is NOT interpreted as a
- * relative lock-time. For future soft-fork compatibility*/
-// https://github.com/bitcoin/bips/blob/master/bip-0112.mediawiki
-pub const SEQUENCE_LOCKTIME_DISABLE_FLAG: u32 = 1 << 31;
-
 /// Maximum script element size allowed by consensus rules
 // https://github.com/bitcoin/bitcoin/blob/42b66a6b814bca130a9ccf0a3f747cf33d628232/src/script/script.h#L23
 pub const MAX_SCRIPT_ELEMENT_SIZE: usize = 520;

src/miniscript/satisfy.rs

@@ -25,11 +25,9 @@ use std::{cmp, i64, mem};
 use bitcoin;
 use bitcoin::hashes::{hash160, ripemd160, sha256, sha256d};
 use bitcoin::secp256k1::XOnlyPublicKey;
+use bitcoin::timelock;
 use bitcoin::util::taproot::{ControlBlock, LeafVersion, TapLeafHash};
 
-use crate::miniscript::limits::{
-    LOCKTIME_THRESHOLD, SEQUENCE_LOCKTIME_DISABLE_FLAG, SEQUENCE_LOCKTIME_TYPE_FLAG,
-};
 use crate::util::witness_size;
 use crate::{Miniscript, MiniscriptKey, ScriptContext, Terminal, ToPublicKey};
 
@@ -110,56 +108,36 @@ pub trait Satisfier<Pk: MiniscriptKey + ToPublicKey> {
     }
 
     /// Assert whether an relative locktime is satisfied
-    fn check_older(&self, _: u32) -> bool {
+    fn check_older(&self, _: timelock::Rel) -> bool {
         false
     }
 
     /// Assert whether a absolute locktime is satisfied
-    fn check_after(&self, _: u32) -> bool {
+    fn check_after(&self, _: timelock::Abs) -> bool {
         false
     }
 }
 
 // Allow use of `()` as a "no conditions available" satisfier
 impl<Pk: MiniscriptKey + ToPublicKey> Satisfier<Pk> for () {}
 
-/// Newtype around `u32` which implements `Satisfier` using `n` as an
-/// relative locktime
-pub struct Older(pub u32);
-
-impl<Pk: MiniscriptKey + ToPublicKey> Satisfier<Pk> for Older {
-    fn check_older(&self, n: u32) -> bool {
-        if self.0 & SEQUENCE_LOCKTIME_DISABLE_FLAG != 0 {
+impl<Pk: MiniscriptKey + ToPublicKey> Satisfier<Pk> for timelock::Rel {
+    fn check_older(&self, n: timelock::Rel) -> bool {
+        if self.is_disabled() {
             return true;
         }
 
-        /* If nSequence encodes a relative lock-time, this mask is
-         * applied to extract that lock-time from the sequence field. */
-        const SEQUENCE_LOCKTIME_MASK: u32 = 0x0000ffff;
-
-        let mask = SEQUENCE_LOCKTIME_MASK | SEQUENCE_LOCKTIME_TYPE_FLAG;
-        let masked_n = n & mask;
-        let masked_seq = self.0 & mask;
-        if masked_n < SEQUENCE_LOCKTIME_TYPE_FLAG && masked_seq >= SEQUENCE_LOCKTIME_TYPE_FLAG {
-            false
-        } else {
-            masked_n <= masked_seq
+        if !self.is_same_type(n) {
+            return false;
         }
+
+        n.value() <= self.value()
     }
 }
 
-/// 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 timelock::Abs {
+    fn check_after(&self, n: timelock::Abs) -> bool {
+        n.is_expired(self.to_u32()).ok().unwrap_or(false)
     }
 }
 
@@ -273,11 +251,11 @@ impl<'a, Pk: MiniscriptKey + ToPublicKey, S: Satisfier<Pk>> Satisfier<Pk> for &'
         (**self).lookup_hash160(h)
     }
 
-    fn check_older(&self, t: u32) -> bool {
+    fn check_older(&self, t: timelock::Rel) -> bool {
         (**self).check_older(t)
     }
 
-    fn check_after(&self, t: u32) -> bool {
+    fn check_after(&self, t: timelock::Abs) -> bool {
         (**self).check_after(t)
     }
 }
@@ -335,11 +313,11 @@ impl<'a, Pk: MiniscriptKey + ToPublicKey, S: Satisfier<Pk>> Satisfier<Pk> for &'
         (**self).lookup_hash160(h)
     }
 
-    fn check_older(&self, t: u32) -> bool {
+    fn check_older(&self, t: timelock::Rel) -> bool {
         (**self).check_older(t)
     }
 
-    fn check_after(&self, t: u32) -> bool {
+    fn check_after(&self, t: timelock::Abs) -> bool {
         (**self).check_after(t)
     }
 }
@@ -473,7 +451,7 @@ macro_rules! impl_tuple_satisfier {
                 None
             }
 
-            fn check_older(&self, n: u32) -> bool {
+            fn check_older(&self, n: timelock::Rel) -> bool {
                 let &($(ref $ty,)*) = self;
                 $(
                     if $ty.check_older(n) {
@@ -483,7 +461,7 @@ macro_rules! impl_tuple_satisfier {
                 false
             }
 
-            fn check_after(&self, n: u32) -> bool {
+            fn check_after(&self, n: timelock::Abs) -> bool {
                 let &($(ref $ty,)*) = self;
                 $(
                     if $ty.check_after(n) {

src/miniscript/types/correctness.rs

@@ -14,6 +14,8 @@
 
 //! Correctness/Soundness type properties
 
+use bitcoin::timelock;
+
 use super::{ErrorKind, Property};
 
 /// Basic type representing where the fragment can go
@@ -187,6 +189,10 @@ impl Property for Correctness {
         }
     }
 
+    fn from_older(_: timelock::Rel) -> Self {
+        Self::from_time(0) // arg is not used.
+    }
+
     fn cast_alt(self) -> Result<Self, ErrorKind> {
         Ok(Correctness {
             base: match self.base {