feat(txscript): introduce human readable viewer

.gitignore

@@ -1,6 +1,7 @@
 target
 web-root
 **/.idea/
+**/.zed/
 /rust-toolchain
 /.vscode/
 **/db-*

crypto/txscript/Cargo.toml

@@ -12,14 +12,20 @@ repository.workspace = true
 [[example]]
 name = "kip-10"
 
+[[example]]
+name = "script-viewer"
+
 [features]
 wasm32-core = []
 wasm32-sdk = []
 
 [dependencies]
 blake2b_simd.workspace = true
 borsh.workspace = true
+bs58.workspace = true
 cfg-if.workspace = true
+faster-hex.workspace = true
+hex.workspace = true
 hexplay.workspace = true
 indexmap.workspace = true
 itertools.workspace = true
@@ -41,11 +47,11 @@ smallvec.workspace = true
 thiserror.workspace = true
 wasm-bindgen.workspace = true
 workflow-wasm.workspace = true
+js-sys.workspace = true
 
 [dev-dependencies]
 criterion.workspace = true
 smallvec.workspace = true
-hex.workspace = true
 serde_json.workspace = true
 
 [[bench]]

crypto/txscript/errors/src/lib.rs

@@ -75,6 +75,8 @@ pub enum TxScriptError {
     Serialization(#[from] SerializationError),
     #[error("sig op count exceeds passed limit of {0}")]
     ExceededSigOpLimit(u8),
+    #[error("expected push opcode")]
+    NonPushData,
 }
 
 #[derive(Error, PartialEq, Eq, Debug, Clone, Copy)]

crypto/txscript/examples/script-viewer.rs

@@ -0,0 +1,19 @@
+use kaspa_consensus_core::{hashing::sighash::SigHashReusedValuesSync, tx::ValidatedTransaction};
+use kaspa_txscript::{script_builder::ScriptBuilder, viewer::ScriptViewerOptions};
+
+fn main() {
+    let script_vec = hex::decode("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").unwrap();
+
+    // build the script from hex
+    let mut s = ScriptBuilder::new();
+    s.script_mut().extend_from_slice(&script_vec);
+
+    // print the hexadecimal form
+    println!("{}", s.hex_view(0, 30));
+
+    // print the human readable form
+    println!(
+        "{}",
+        s.string_view::<ValidatedTransaction, SigHashReusedValuesSync>(ScriptViewerOptions { contains_redeem_script: false })
+    );
+}

crypto/txscript/src/lib.rs

@@ -4,11 +4,13 @@ extern crate core;
 pub mod caches;
 mod data_stack;
 pub mod error;
+pub mod multi_sig;
 pub mod opcodes;
 pub mod result;
 pub mod script_builder;
 pub mod script_class;
 pub mod standard;
+pub mod viewer;
 #[cfg(feature = "wasm32-sdk")]
 pub mod wasm;
 

crypto/txscript/src/multi_sig.rs

@@ -0,0 +1,63 @@
+use crate::opcodes::to_small_int;
+use kaspa_consensus_core::{hashing::sighash::SigHashReusedValues, tx::VerifiableTransaction};
+use kaspa_txscript_errors::TxScriptError;
+
+use crate::opcodes::OpCodeImplementation;
+
+#[derive(Debug)]
+pub struct MultiSigSchnorrScriptParameters {
+    pub required_signatures_count: u8,
+    pub signers_count: u8,
+    pub signers_pubkey: Vec<secp256k1::XOnlyPublicKey>,
+}
+
+/// Extract parameters from a standard multisig script (schnorr):
+///   OP_m <pubkey1> ... <pubkeyn> OP_n OP_CHECKMULTISIG
+pub fn get_schnorr_multisig_params<T: VerifiableTransaction, Reused: SigHashReusedValues>(
+    opcodes: &[Box<dyn OpCodeImplementation<T, Reused>>],
+    checkmultisig_index: usize,
+) -> Result<MultiSigSchnorrScriptParameters, TxScriptError> {
+    let op_n = opcodes
+        .get(checkmultisig_index.checked_sub(1).ok_or_else(|| TxScriptError::InvalidState("index out of bounds".into()))?)
+        .ok_or_else(|| TxScriptError::InvalidState("index out of bounds".into()))?;
+
+    let n = to_small_int(op_n);
+    if n == 0 {
+        return Err(TxScriptError::InvalidPubKeyCount("n must be >= 1".into()));
+    }
+    let n_usize = n as usize;
+
+    let pubkeys_end = checkmultisig_index.checked_sub(1).ok_or_else(|| TxScriptError::InvalidState("index out of bounds".into()))?;
+    let pubkeys_start = pubkeys_end.checked_sub(n_usize).ok_or_else(|| TxScriptError::InvalidState("index out of bounds".into()))?;
+
+    let pubkeys_ops =
+        opcodes.get(pubkeys_start..pubkeys_end).ok_or_else(|| TxScriptError::InvalidState("index out of bounds".into()))?;
+
+    let mut pubkeys = Vec::with_capacity(n_usize);
+    for op in pubkeys_ops {
+        if !op.is_push_opcode() {
+            return Err(TxScriptError::InvalidOpcode("expected push opcode for pubkey".into()));
+        }
+        let data = op.get_data();
+
+        match data.len() {
+            32 => {
+                let pk = secp256k1::XOnlyPublicKey::from_slice(data).map_err(|_| TxScriptError::PubKeyFormat)?;
+                pubkeys.push(pk);
+            }
+            _ => return Err(TxScriptError::PubKeyFormat),
+        }
+    }
+
+    let op_m = opcodes
+        .get(pubkeys_start.checked_sub(1).ok_or_else(|| TxScriptError::InvalidState("index out of bounds".into()))?)
+        .ok_or_else(|| TxScriptError::InvalidState("index out of bounds".into()))?;
+
+    let m = to_small_int(op_m);
+
+    if m > n {
+        return Err(TxScriptError::InvalidSignatureCount("m must be <= n".into()));
+    }
+
+    Ok(MultiSigSchnorrScriptParameters { required_signatures_count: m, signers_count: n, signers_pubkey: pubkeys })
+}

crypto/txscript/src/opcodes/macros.rs

@@ -62,7 +62,7 @@ macro_rules! opcode_init {
 }
 
 macro_rules! opcode_impl {
-    ($name: ident, $num: literal, $length: tt, $code: expr, $self:ident, $vm:ident ) => {
+    ($name: ident, $str_rep: literal, $num: literal, $length: tt, $code: expr, $self:ident, $vm:ident ) => {
         type $name = OpCode<$num>;
 
         impl OpcodeSerialization for $name {
@@ -83,11 +83,17 @@ macro_rules! opcode_impl {
         }
 
         impl<T: VerifiableTransaction, Reused: SigHashReusedValues> OpCodeImplementation<T, Reused> for $name {}
+
+        impl std::fmt::Display for $name {
+            fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+                write!(f, $str_rep)
+            }
+        }
     }
 }
 
 macro_rules! opcode_list {
-    ( $( opcode $(|$alias:ident|)? $name:ident<$num:literal, $length:tt>($self:ident, $vm:ident) $code: expr ) *)  => {
+    ( $( opcode $(|$alias:ident|)? $name:ident<$str_rep:literal, $num:literal, $length:tt>($self:ident, $vm:ident) $code: expr ) *)  => {
         pub mod codes {
             $(
                 #[allow(non_upper_case_globals)]
@@ -103,7 +109,7 @@ macro_rules! opcode_list {
         }
 
         $(
-            opcode_impl!($name, $num, $length, $code, $self, $vm);
+            opcode_impl!($name, $str_rep, $num, $length, $code, $self, $vm);
 
             $(
                 #[allow(dead_code)]