Merge pull request #121 from sanket1729/heightlocks

Detect miniscripts that have a satisfaction with a combination of time locks and height locks

Author: apoelstra

examples/htlc.rs

@@ -39,8 +39,9 @@ fn main() {
     );
 
     assert_eq!(
-        format!("{}", htlc_descriptor.lift()),
-        "or(and(pkh(4377a5acd66dc5cb67148a24818d1e51fa183bd2),pkh(4377a5acd66dc5cb67148a24818d1e51fa183bd2),older(4444)),sha256(1111111111111111111111111111111111111111111111111111111111111111))");
+        format!("{}", htlc_descriptor.lift().unwrap()),
+        "or(and(pkh(4377a5acd66dc5cb67148a24818d1e51fa183bd2),pkh(4377a5acd66dc5cb67148a24818d1e51fa183bd2),older(4444)),sha256(1111111111111111111111111111111111111111111111111111111111111111))"
+    );
 
     assert_eq!(
         format!("{:x}", htlc_descriptor.script_pubkey()),

fuzz/fuzz_targets/compile_descriptor.rs

@@ -15,7 +15,7 @@ fn do_test(data: &[u8]) {
         // Compile
         if let Ok(desc) = pol.compile::<Segwitv0>() {
             // Lift
-            assert_eq!(desc.clone().lift(), pol.clone().lift());
+            assert_eq!(desc.clone().lift().unwrap(), pol.clone().lift().unwrap());
             // Try to roundtrip the output of the compiler
             let output = desc.to_string();
             if let Ok(desc) = DummyScript::from_str(&output) {

src/miniscript/astelem.rs

@@ -710,7 +710,7 @@ impl<Pk: MiniscriptKey + ToPublicKey, Ctx: ScriptContext> Terminal<Pk, Ctx> {
             Terminal::Check(ref sub) => sub.node.script_size() + 1,
             Terminal::DupIf(ref sub) => sub.node.script_size() + 3,
             Terminal::Verify(ref sub) => {
-                sub.node.script_size() + if sub.ext.has_verify_form { 0 } else { 1 }
+                sub.node.script_size() + if sub.ext.has_free_verify { 0 } else { 1 }
             }
             Terminal::NonZero(ref sub) => sub.node.script_size() + 4,
             Terminal::ZeroNotEqual(ref sub) => sub.node.script_size() + 1,

src/miniscript/mod.rs

@@ -659,7 +659,7 @@ mod tests {
             keys[4].to_string(),
         );
 
-        let mut abs = miniscript.lift();
+        let mut abs = miniscript.lift().unwrap();
         assert_eq!(abs.n_keys(), 5);
         assert_eq!(abs.minimum_n_keys(), 2);
         abs = abs.at_age(10000);

src/miniscript/satisfy.rs

@@ -25,6 +25,7 @@ use bitcoin::hashes::{hash160, ripemd160, sha256, sha256d};
 use bitcoin::{self, secp256k1};
 use {MiniscriptKey, ToPublicKey};
 
+use miniscript::types::extra_props::HEIGHT_TIME_THRESHOLD;
 use ScriptContext;
 use Terminal;
 
@@ -94,7 +95,12 @@ pub struct Older(pub u32);
 
 impl<Pk: MiniscriptKey> Satisfier<Pk> for Older {
     fn check_older(&self, n: u32) -> bool {
-        n <= self.0
+        // if n > self.0; we will be returning false anyways
+        if n < HEIGHT_TIME_THRESHOLD && self.0 >= HEIGHT_TIME_THRESHOLD {
+            false
+        } else {
+            n <= self.0
+        }
     }
 }
 
@@ -104,7 +110,12 @@ pub struct After(pub u32);
 
 impl<Pk: MiniscriptKey> Satisfier<Pk> for After {
     fn check_after(&self, n: u32) -> bool {
-        n <= self.0
+        // if n > self.0; we will be returning false anyways
+        if n < HEIGHT_TIME_THRESHOLD && self.0 >= HEIGHT_TIME_THRESHOLD {
+            false
+        } else {
+            n <= self.0
+        }
     }
 }