Cleanup context code with SigType enum

NoChecks context needs to know how to serialize the given public key or
where to lookup for it's signature (schnorr or ecdsa). The simplest way
to convey this information is to separate out NoChecks for ecdsa and
schnorr. When using NoChecksEcdsa the associated type
bitcoin::PublicKey or when using NoChecksSchnorr, the associated type
XOnlyPublicKey should take care of it.

Author: sanket1729

src/interpreter/inner.rs

@@ -17,7 +17,7 @@ use bitcoin::blockdata::witness::Witness;
 use bitcoin::hashes::{hash160, sha256, Hash};
 
 use super::{stack, Error, Stack};
-use miniscript::context::NoChecks;
+use miniscript::context::NoChecksEcdsa;
 use {Miniscript, MiniscriptKey};
 
 /// Attempts to parse a slice as a Bitcoin public key, checking compressedness
@@ -48,7 +48,7 @@ fn pk_from_stackelem<'a>(
 
 fn script_from_stackelem<'a>(
     elem: &stack::Element<'a>,
-) -> Result<Miniscript<bitcoin::PublicKey, NoChecks>, Error> {
+) -> Result<Miniscript<bitcoin::PublicKey, NoChecksEcdsa>, Error> {
     match *elem {
         stack::Element::Push(sl) => {
             Miniscript::<bitcoin::PublicKey, _>::parse_insane(&bitcoin::Script::from(sl.to_owned()))
@@ -86,7 +86,7 @@ pub enum Inner {
     /// pay-to-pkhash or pay-to-witness-pkhash)
     PublicKey(bitcoin::PublicKey, PubkeyType),
     /// The script being evaluated is an actual script
-    Script(Miniscript<bitcoin::PublicKey, NoChecks>, ScriptType),
+    Script(Miniscript<bitcoin::PublicKey, NoChecksEcdsa>, ScriptType),
 }
 
 // The `Script` returned by this method is always generated/cloned ... when
@@ -598,7 +598,7 @@ mod tests {
     fn script_bare() {
         let preimage = b"12345678----____12345678----____";
         let hash = hash160::Hash::hash(&preimage[..]);
-        let miniscript: ::Miniscript<bitcoin::PublicKey, NoChecks> =
+        let miniscript: ::Miniscript<bitcoin::PublicKey, NoChecksEcdsa> =
             ::Miniscript::from_str_insane(&format!("hash160({})", hash)).unwrap();
 
         let spk = miniscript.encode();
@@ -625,7 +625,7 @@ mod tests {
     fn script_sh() {
         let preimage = b"12345678----____12345678----____";
         let hash = hash160::Hash::hash(&preimage[..]);
-        let miniscript: ::Miniscript<bitcoin::PublicKey, NoChecks> =
+        let miniscript: ::Miniscript<bitcoin::PublicKey, NoChecksEcdsa> =
             ::Miniscript::from_str_insane(&format!("hash160({})", hash)).unwrap();
 
         let redeem_script = miniscript.encode();
@@ -663,7 +663,7 @@ mod tests {
     fn script_wsh() {
         let preimage = b"12345678----____12345678----____";
         let hash = hash160::Hash::hash(&preimage[..]);
-        let miniscript: ::Miniscript<bitcoin::PublicKey, NoChecks> =
+        let miniscript: ::Miniscript<bitcoin::PublicKey, NoChecksEcdsa> =
             ::Miniscript::from_str_insane(&format!("hash160({})", hash)).unwrap();
 
         let witness_script = miniscript.encode();
@@ -701,7 +701,7 @@ mod tests {
     fn script_sh_wsh() {
         let preimage = b"12345678----____12345678----____";
         let hash = hash160::Hash::hash(&preimage[..]);
-        let miniscript: ::Miniscript<bitcoin::PublicKey, NoChecks> =
+        let miniscript: ::Miniscript<bitcoin::PublicKey, NoChecksEcdsa> =
             ::Miniscript::from_str_insane(&format!("hash160({})", hash)).unwrap();
 
         let witness_script = miniscript.encode();

src/interpreter/mod.rs

@@ -23,7 +23,7 @@ use bitcoin::blockdata::witness::Witness;
 use bitcoin::hashes::{hash160, ripemd160, sha256, sha256d};
 use bitcoin::util::sighash;
 use bitcoin::{self, secp256k1};
-use miniscript::context::NoChecks;
+use miniscript::context::NoChecksEcdsa;
 use miniscript::ScriptContext;
 use Miniscript;
 use Terminal;
@@ -311,7 +311,7 @@ pub enum SatisfiedConstraint<'intp, 'txin> {
 ///depending on evaluation of the children.
 struct NodeEvaluationState<'intp> {
     ///The node which is being evaluated
-    node: &'intp Miniscript<bitcoin::PublicKey, NoChecks>,
+    node: &'intp Miniscript<bitcoin::PublicKey, NoChecksEcdsa>,
     ///number of children evaluated
     n_evaluated: usize,
     ///number of children satisfied
@@ -342,7 +342,7 @@ pub struct Iter<'intp, 'txin: 'intp, F: FnMut(&bitcoin::PublicKey, bitcoin::Ecds
 ///Iterator for Iter
 impl<'intp, 'txin: 'intp, F> Iterator for Iter<'intp, 'txin, F>
 where
-    NoChecks: ScriptContext,
+    NoChecksEcdsa: ScriptContext,
     F: FnMut(&bitcoin::PublicKey, bitcoin::EcdsaSig) -> bool,
 {
     type Item = Result<SatisfiedConstraint<'intp, 'txin>, Error>;
@@ -363,13 +363,13 @@ where
 
 impl<'intp, 'txin: 'intp, F> Iter<'intp, 'txin, F>
 where
-    NoChecks: ScriptContext,
+    NoChecksEcdsa: ScriptContext,
     F: FnMut(&bitcoin::PublicKey, bitcoin::EcdsaSig) -> bool,
 {
     /// Helper function to push a NodeEvaluationState on state stack
     fn push_evaluation_state(
         &mut self,
-        node: &'intp Miniscript<bitcoin::PublicKey, NoChecks>,
+        node: &'intp Miniscript<bitcoin::PublicKey, NoChecksEcdsa>,
         n_evaluated: usize,
         n_satisfied: usize,
     ) -> () {
@@ -796,7 +796,7 @@ mod tests {
     use bitcoin;
     use bitcoin::hashes::{hash160, ripemd160, sha256, sha256d, Hash};
     use bitcoin::secp256k1::{self, Secp256k1, VerifyOnly};
-    use miniscript::context::NoChecks;
+    use miniscript::context::NoChecksEcdsa;
     use Miniscript;
     use MiniscriptKey;
     use ToPublicKey;
@@ -848,7 +848,7 @@ mod tests {
         fn from_stack<'txin, 'elem, F>(
             verify_fn: F,
             stack: &'elem mut Stack<'txin>,
-            ms: &'elem Miniscript<bitcoin::PublicKey, NoChecks>,
+            ms: &'elem Miniscript<bitcoin::PublicKey, NoChecksEcdsa>,
         ) -> Iter<'elem, 'txin, F>
         where
             F: FnMut(&bitcoin::PublicKey, bitcoin::EcdsaSig) -> bool,

src/miniscript/astelem.rs

@@ -29,6 +29,7 @@ use bitcoin::hashes::{hash160, ripemd160, sha256, sha256d, Hash};
 
 use errstr;
 use expression;
+use miniscript::context::SigType;
 use miniscript::types::{self, Property};
 use miniscript::ScriptContext;
 use script_num_size;
@@ -761,7 +762,7 @@ impl<Pk: MiniscriptKey, Ctx: ScriptContext> Terminal<Pk, Ctx> {
                     .push_opcode(opcodes::all::OP_EQUAL)
             }
             Terminal::Multi(k, ref keys) => {
-                debug_assert!(!Ctx::is_tap());
+                debug_assert!(Ctx::sig_type() == SigType::Ecdsa);
                 builder = builder.push_int(k as i64);
                 for pk in keys {
                     builder = builder.push_key(&pk.to_public_key());
@@ -771,7 +772,7 @@ impl<Pk: MiniscriptKey, Ctx: ScriptContext> Terminal<Pk, Ctx> {
                     .push_opcode(opcodes::all::OP_CHECKMULTISIG)
             }
             Terminal::MultiA(k, ref keys) => {
-                debug_assert!(Ctx::is_tap());
+                debug_assert!(Ctx::sig_type() == SigType::Schnorr);
                 // keys must be atleast len 1 here, guaranteed by typing rules
                 builder = builder.push_ms_key::<_, Ctx>(&keys[0]);
                 builder = builder.push_opcode(opcodes::all::OP_CHECKSIG);