feat(api): decouple the verification of Tx and spentproofs from DbcBu…

…ilder::build

- A new DbcBuilder::build_without_verifying API is introduced which doesn't perform
Tx or spentproofs verification.

examples/mint-repl/mint-repl.rs

@@ -426,7 +426,7 @@ fn print_dbc_human(dbc: &Dbc, outputs: bool, secret_key_base: Option<SecretKey>)
     Ok(())
 }
 
-/// handles decode command.  
+/// handles decode command.
 fn decode_input() -> Result<()> {
     let t = readline_prompt(
         "\n[d: DBC, rt: RingCtTransaction, pks: PublicKeySet, sks: SecretKeySet]\nType: ",
@@ -508,14 +508,14 @@ fn decode_input() -> Result<()> {
 fn print_logo() {
     println!(
         r#"
- __     _                        
-(_  _._|__  |\ | __|_     _ ._|  
-__)(_| |(/_ | \|(/_|_\/\/(_)| |< 
- ____  ____   ____   __  __ _       _   
-|  _ \| __ ) / ___| |  \/  (_)_ __ | |_ 
+ __     _
+(_  _._|__  |\ | __|_     _ ._|
+__)(_| |(/_ | \|(/_|_\/\/(_)| |<
+ ____  ____   ____   __  __ _       _
+|  _ \| __ ) / ___| |  \/  (_)_ __ | |_
 | | | |  _ \| |     | |\/| | | '_ \| __|
-| |_| | |_) | |___  | |  | | | | | | |_ 
-|____/|____/ \____| |_|  |_|_|_| |_|\__|        
+| |_| | |_) | |___  | |  | | | | | | |_
+|____/|____/ \____| |_|  |_|_|_| |_|\__|
   "#
     );
 }

src/builder.rs

@@ -387,7 +387,7 @@ impl DbcBuilder {
         self
     }
 
-    /// Build the output DBCs
+    /// Build the output DBCs, verifying the transaction and spentproofs.
     ///
     /// see TransactionVerifier::verify() for a description of
     /// verifier requirements.
@@ -401,6 +401,21 @@ impl DbcBuilder {
         // note that we do this just once for entire Tx, not once per output Dbc.
         TransactionVerifier::verify(verifier, &self.transaction, &spent_proofs)?;
 
+        // build output DBCs
+        self.build_output_dbcs(spent_proofs)
+    }
+
+    /// Build the output DBCs (no verification over Tx or spentproof is performed).
+    pub fn build_without_verifying(self) -> Result<Vec<(Dbc, OwnerOnce, AmountSecrets)>> {
+        let spent_proofs = self.spent_proofs()?;
+        self.build_output_dbcs(spent_proofs)
+    }
+
+    // Private helper to build output DBCs
+    fn build_output_dbcs(
+        self,
+        spent_proofs: BTreeSet<SpentProof>,
+    ) -> Result<Vec<(Dbc, OwnerOnce, AmountSecrets)>> {
         let pc_gens = PedersenGens::default();
         let output_commitments: Vec<(Commitment, RevealedCommitment)> = self
             .revealed_commitments

src/owner.rs

@@ -139,7 +139,7 @@ impl From<OwnerOnce> for Owner {
 /// The one-time-use Owner key(pair) is derived from a reusable
 /// base Owner key(pair) using the DerivationIndex.
 #[cfg_attr(feature = "serde", derive(Serialize, Deserialize))]
-#[derive(Clone, Debug)]
+#[derive(Clone, Debug, PartialEq)]
 pub struct OwnerOnce {
     pub owner_base: Owner,
     pub derivation_index: DerivationIndex,