PSBT Bugfix for multiple of same pubkey in p2ms

Author: junderw

src/psbt.js

@@ -568,15 +568,27 @@ function canFinalize(input, script, scriptType) {
       return hasSigs(1, input.partialSig);
     case 'multisig':
       const p2ms = payments.p2ms({ output: script });
-      return hasSigs(p2ms.m, input.partialSig);
+      return hasSigs(p2ms.m, input.partialSig, p2ms.pubkeys);
     default:
       return false;
   }
 }
-function hasSigs(neededSigs, partialSig) {
+function hasSigs(neededSigs, partialSig, pubkeys) {
   if (!partialSig) return false;
-  if (partialSig.length > neededSigs) throw new Error('Too many signatures');
-  return partialSig.length === neededSigs;
+  let sigs;
+  if (pubkeys) {
+    sigs = pubkeys
+      .map(pkey => {
+        const pubkey = ecpair_1.fromPublicKey(pkey, { compressed: true })
+          .publicKey;
+        return partialSig.filter(pSig => pSig.pubkey.equals(pubkey))[0];
+      })
+      .filter(v => !!v);
+  } else {
+    sigs = partialSig;
+  }
+  if (sigs.length > neededSigs) throw new Error('Too many signatures');
+  return sigs.length === neededSigs;
 }
 function isFinalized(input) {
   return !!input.finalScriptSig || !!input.finalScriptWitness;

test/integration/transactions.spec.ts

@@ -530,6 +530,36 @@ describe('bitcoinjs-lib (transactions with psbt)', () => {
     },
   );
 
+  it(
+    'can create (and broadcast via 3PBP) a Transaction, w/ a ' +
+      'P2SH(P2MS(2 of 2)) input with nonWitnessUtxo',
+    async () => {
+      const myKey = bitcoin.ECPair.makeRandom({ network: regtest });
+      const myKeys = [
+        myKey,
+        bitcoin.ECPair.fromPrivateKey(myKey.privateKey!, { network: regtest }),
+      ];
+      const p2sh = createPayment('p2sh-p2ms(2 of 2)', myKeys);
+      const inputData = await getInputData(5e4, p2sh.payment, false, 'p2sh');
+      const psbt = new bitcoin.Psbt({ network: regtest })
+        .addInput(inputData)
+        .addOutput({
+          address: regtestUtils.RANDOM_ADDRESS,
+          value: 2e4,
+        })
+        .signInput(0, p2sh.keys[0]);
+      psbt.finalizeAllInputs();
+      const tx = psbt.extractTransaction();
+      await regtestUtils.broadcast(tx.toHex());
+      await regtestUtils.verify({
+        txId: tx.getId(),
+        address: regtestUtils.RANDOM_ADDRESS,
+        vout: 0,
+        value: 2e4,
+      });
+    },
+  );
+
   it('can create (and broadcast via 3PBP) a Transaction, w/ a P2WPKH input using HD', async () => {
     const hdRoot = bip32.fromSeed(rng(64));
     const masterFingerprint = hdRoot.fingerprint;

ts_src/psbt.ts

@@ -747,16 +747,32 @@ function canFinalize(
       return hasSigs(1, input.partialSig);
     case 'multisig':
       const p2ms = payments.p2ms({ output: script });
-      return hasSigs(p2ms.m!, input.partialSig);
+      return hasSigs(p2ms.m!, input.partialSig, p2ms.pubkeys);
     default:
       return false;
   }
 }
 
-function hasSigs(neededSigs: number, partialSig?: any[]): boolean {
+function hasSigs(
+  neededSigs: number,
+  partialSig?: any[],
+  pubkeys?: Buffer[],
+): boolean {
   if (!partialSig) return false;
-  if (partialSig.length > neededSigs) throw new Error('Too many signatures');
-  return partialSig.length === neededSigs;
+  let sigs: any;
+  if (pubkeys) {
+    sigs = pubkeys
+      .map(pkey => {
+        const pubkey = ecPairFromPublicKey(pkey, { compressed: true })
+          .publicKey;
+        return partialSig.filter(pSig => pSig.pubkey.equals(pubkey))[0];
+      })
+      .filter(v => !!v);
+  } else {
+    sigs = partialSig;
+  }
+  if (sigs.length > neededSigs) throw new Error('Too many signatures');
+  return sigs.length === neededSigs;
 }
 
 function isFinalized(input: PsbtInput): boolean {