feat(abstract-utxo): include script type in input signing error

Include PSBT script type in InputSigningError to improve debugging of
transaction signing issues. This provides better visibility into which
input types are failing during the signing process.

Issue: BTC-2806

Co-authored-by: llm-git <[email protected]>

Author: OttoAllmendinger

modules/abstract-utxo/src/transaction/fixedScript/sign.ts

@@ -11,7 +11,7 @@ type Unspent<TNumber extends number | bigint = number> = utxolib.bitgo.Unspent<T
 
 type RootWalletKeys = utxolib.bitgo.RootWalletKeys;
 
-type PsbtParsedScriptTypes =
+type PsbtParsedScriptType =
   | 'p2sh'
   | 'p2wsh'
   | 'p2shP2wsh'
@@ -22,17 +22,24 @@ type PsbtParsedScriptTypes =
 export class InputSigningError<TNumber extends number | bigint = number> extends Error {
   static expectedWalletUnspent<TNumber extends number | bigint>(
     inputIndex: number,
+    inputType: PsbtParsedScriptType | null, // null for legacy transaction format
     unspent: Unspent<TNumber> | { id: string }
   ): InputSigningError<TNumber> {
-    return new InputSigningError(inputIndex, unspent, `not a wallet unspent, not a replay protection unspent`);
+    return new InputSigningError(
+      inputIndex,
+      inputType,
+      unspent,
+      `not a wallet unspent, not a replay protection unspent`
+    );
   }
 
   constructor(
     public inputIndex: number,
+    public inputType: PsbtParsedScriptType | null, // null for legacy transaction format
     public unspent: Unspent<TNumber> | { id: string },
     public reason: Error | string
   ) {
-    super(`signing error at input ${inputIndex}: unspentId=${unspent.id}: ${reason}`);
+    super(`signing error at input ${inputIndex}: type=${inputType} unspentId=${unspent.id}: ${reason}`);
   }
 }
 
@@ -70,7 +77,7 @@ export function signAndVerifyPsbt(
 ): utxolib.bitgo.UtxoPsbt | utxolib.bitgo.UtxoTransaction<bigint> {
   const txInputs = psbt.txInputs;
   const outputIds: string[] = [];
-  const scriptTypes: PsbtParsedScriptTypes[] = [];
+  const scriptTypes: PsbtParsedScriptType[] = [];
 
   const signErrors: InputSigningError<bigint>[] = psbt.data.inputs
     .map((input, inputIndex: number) => {
@@ -89,7 +96,7 @@ export function signAndVerifyPsbt(
         psbt.signInputHD(inputIndex, signerKeychain);
         debug('Successfully signed input %d of %d', inputIndex + 1, psbt.data.inputs.length);
       } catch (e) {
-        return new InputSigningError<bigint>(inputIndex, { id: outputId }, e);
+        return new InputSigningError<bigint>(inputIndex, scriptType, { id: outputId }, e);
       }
     })
     .filter((e): e is InputSigningError<bigint> => e !== undefined);
@@ -109,11 +116,11 @@ export function signAndVerifyPsbt(
       const outputId = outputIds[inputIndex];
       try {
         if (!psbt.validateSignaturesOfInputHD(inputIndex, signerKeychain)) {
-          return new InputSigningError(inputIndex, { id: outputId }, new Error(`invalid signature`));
+          return new InputSigningError(inputIndex, scriptType, { id: outputId }, new Error(`invalid signature`));
         }
       } catch (e) {
         debug('Invalid signature');
-        return new InputSigningError<bigint>(inputIndex, { id: outputId }, e);
+        return new InputSigningError<bigint>(inputIndex, scriptType, { id: outputId }, e);
       }
     })
     .filter((e): e is InputSigningError<bigint> => e !== undefined);
@@ -178,13 +185,13 @@ export function signAndVerifyWalletTransaction<TNumber extends number | bigint>(
         return;
       }
       if (!isWalletUnspent<TNumber>(unspent)) {
-        return InputSigningError.expectedWalletUnspent<TNumber>(inputIndex, unspent);
+        return InputSigningError.expectedWalletUnspent<TNumber>(inputIndex, null, unspent);
       }
       try {
         signInputWithUnspent<TNumber>(txBuilder, inputIndex, unspent, walletSigner);
         debug('Successfully signed input %d of %d', inputIndex + 1, unspents.length);
       } catch (e) {
-        return new InputSigningError<TNumber>(inputIndex, unspent, e);
+        return new InputSigningError<TNumber>(inputIndex, null, unspent, e);
       }
     })
     .filter((e): e is InputSigningError<TNumber> => e !== undefined);
@@ -203,18 +210,18 @@ export function signAndVerifyWalletTransaction<TNumber extends number | bigint>(
         return;
       }
       if (!isWalletUnspent<TNumber>(unspent)) {
-        return InputSigningError.expectedWalletUnspent<TNumber>(inputIndex, unspent);
+        return InputSigningError.expectedWalletUnspent<TNumber>(inputIndex, null, unspent);
       }
       try {
         const publicKey = walletSigner.deriveForChainAndIndex(unspent.chain, unspent.index).signer.publicKey;
         if (
           !utxolib.bitgo.verifySignatureWithPublicKey<TNumber>(signedTransaction, inputIndex, prevOutputs, publicKey)
         ) {
-          return new InputSigningError(inputIndex, unspent, new Error(`invalid signature`));
+          return new InputSigningError(inputIndex, null, unspent, new Error(`invalid signature`));
         }
       } catch (e) {
         debug('Invalid signature');
-        return new InputSigningError<TNumber>(inputIndex, unspent, e);
+        return new InputSigningError<TNumber>(inputIndex, null, unspent, e);
       }
     })
     .filter((e): e is InputSigningError<TNumber> => e !== undefined);