feat(applying): validate all inputs in UTxO set (#324)

pallas-applying/src/byron.rs

@@ -1,18 +1,19 @@
 //! Utilities required for Byron-era transaction validation.
 
-use crate::types::{ByronProtParams, UTxOs, ValidationError, ValidationResult};
+use crate::types::{ByronProtParams, MultiEraInput, UTxOs, ValidationError, ValidationResult};
 
 use pallas_primitives::byron::{MintedTxPayload, Tx};
 
 // TODO: implement missing validation rules.
 pub fn validate_byron_tx(
     mtxp: &MintedTxPayload,
-    _utxos: &UTxOs,
+    utxos: &UTxOs,
     _prot_pps: &ByronProtParams,
 ) -> ValidationResult {
     let tx: &Tx = &mtxp.transaction;
     check_ins_not_empty(tx)?;
-    check_outs_not_empty(tx)
+    check_outs_not_empty(tx)?;
+    check_ins_in_utxos(tx, utxos)
 }
 
 fn check_ins_not_empty(tx: &Tx) -> ValidationResult {
@@ -28,3 +29,12 @@ fn check_outs_not_empty(tx: &Tx) -> ValidationResult {
     }
     Ok(())
 }
+
+fn check_ins_in_utxos(tx: &Tx, utxos: &UTxOs) -> ValidationResult {
+    for input in tx.inputs.iter() {
+        if !(utxos.contains_key(&MultiEraInput::from_byron(input))) {
+            return Err(ValidationError::InputMissingInUTxO);
+        }
+    }
+    Ok(())
+}

pallas-applying/src/types.rs

@@ -21,6 +21,7 @@ pub enum MultiEraProtParams<'b> {
 #[derive(Debug)]
 #[non_exhaustive]
 pub enum ValidationError {
+    InputMissingInUTxO,
     TxInsEmpty,
     TxOutsEmpty,
 }