Add input signature_script checking to submitTransaction RPC

[KaffinPX]

Closes #452

[aspect]

LGTM!

[michaelsutton]

I suggest the following instead of the above approach:

diff --git a/consensus/Cargo.toml b/consensus/Cargo.toml
index f151e404b..3f4a1b456 100644
--- a/consensus/Cargo.toml
+++ b/consensus/Cargo.toml
@@ -30,6 +30,7 @@ kaspa-muhash.workspace = true
 kaspa-notify.workspace = true
 kaspa-pow.workspace = true
 kaspa-txscript.workspace = true
+kaspa-txscript-errors.workspace = true
 kaspa-utils.workspace = true
 log.workspace = true
 once_cell.workspace = true
diff --git a/consensus/core/src/errors/tx.rs b/consensus/core/src/errors/tx.rs
index ec1899faa..1aeb5220f 100644
--- a/consensus/core/src/errors/tx.rs
+++ b/consensus/core/src/errors/tx.rs
@@ -80,6 +80,9 @@ pub enum TxRuleError {
     #[error("failed to verify the signature script: {0}")]
     SignatureInvalid(TxScriptError),
 
+    #[error("failed to verify empty signature script. Inner error: {0}")]
+    SignatureEmpty(TxScriptError),
+
     #[error("input {0} sig op count is {1}, but the calculated value is {2}")]
     WrongSigOpCount(usize, u64, u64),
 
diff --git a/consensus/src/processes/transaction_validator/transaction_validator_populated.rs b/consensus/src/processes/transaction_validator/transaction_validator_populated.rs
index 1835ba61e..586b23e57 100644
--- a/consensus/src/processes/transaction_validator/transaction_validator_populated.rs
+++ b/consensus/src/processes/transaction_validator/transaction_validator_populated.rs
@@ -1,7 +1,11 @@
 use crate::constants::{MAX_SOMPI, SEQUENCE_LOCK_TIME_DISABLED, SEQUENCE_LOCK_TIME_MASK};
-use kaspa_consensus_core::{hashing::sighash::SigHashReusedValues, tx::VerifiableTransaction};
+use kaspa_consensus_core::{
+    hashing::sighash::SigHashReusedValues,
+    tx::{TransactionInput, VerifiableTransaction},
+};
 use kaspa_core::warn;
 use kaspa_txscript::{get_sig_op_count, TxScriptEngine};
+use kaspa_txscript_errors::TxScriptError;
 
 use super::{
     errors::{TxResult, TxRuleError},
@@ -167,14 +171,21 @@ impl TransactionValidator {
         let mut reused_values = SigHashReusedValues::new();
         for (i, (input, entry)) in tx.populated_inputs().enumerate() {
             let mut engine = TxScriptEngine::from_transaction_input(tx, input, i, entry, &mut reused_values, &self.sig_cache)
-                .map_err(TxRuleError::SignatureInvalid)?;
-            engine.execute().map_err(TxRuleError::SignatureInvalid)?;
+                .map_err(|err| map_script_err(err, input))?;
+            engine.execute().map_err(|err| map_script_err(err, input))?;
         }
 
         Ok(())
     }
 }
 
+fn map_script_err(script_err: TxScriptError, input: &TransactionInput) -> TxRuleError {
+    match input.signature_script.is_empty() {
+        true => TxRuleError::SignatureEmpty(script_err),
+        false => TxRuleError::SignatureInvalid(script_err),
+    }
+}
+
 #[cfg(test)]
 mod tests {
     use super::super::errors::TxRuleError;

[biryukovmaxim]

match input.signature_script.is_empty() {
+        true => TxRuleError::SignatureEmpty(script_err),
+        false => TxRuleError::SignatureInvalid(script_err),
+    }

match bool always looks weird. Why not use simple if-else?