Check signatures for sighash type before finalize

src/psbt.js

@@ -216,6 +216,7 @@ class Psbt extends bip174_1.Psbt {
     const scriptType = classifyScript(script);
     if (!canFinalize(input, script, scriptType))
       throw new Error(`Can not finalize input #${inputIndex}`);
+    checkPartialSigSighashes(input);
     const { finalScriptSig, finalScriptWitness } = getFinalScripts(
       script,
       scriptType,
@@ -446,6 +447,16 @@ function checkInputsForPartialSig(inputs, action) {
     }
   });
 }
+function checkPartialSigSighashes(input) {
+  if (!input.sighashType || !input.partialSig) return;
+  const { partialSig, sighashType } = input;
+  partialSig.forEach(pSig => {
+    const { hashType } = bscript.signature.decode(pSig.signature);
+    if (sighashType !== hashType) {
+      throw new Error('Signature sighash does not match input sighash type');
+    }
+  });
+}
 function checkScriptForPubkey(pubkey, script, action) {
   const pubkeyHash = crypto_1.hash160(pubkey);
   const decompiled = bscript.decompile(script);

ts_src/psbt.ts

@@ -269,6 +269,8 @@ export class Psbt extends PsbtBase {
     if (!canFinalize(input, script, scriptType))
       throw new Error(`Can not finalize input #${inputIndex}`);
 
+    checkPartialSigSighashes(input);
+
     const { finalScriptSig, finalScriptWitness } = getFinalScripts(
       script,
       scriptType,
@@ -547,6 +549,17 @@ function checkInputsForPartialSig(inputs: PsbtInput[], action: string): void {
   });
 }
 
+function checkPartialSigSighashes(input: PsbtInput): void {
+  if (!input.sighashType || !input.partialSig) return;
+  const { partialSig, sighashType } = input;
+  partialSig.forEach(pSig => {
+    const { hashType } = bscript.signature.decode(pSig.signature);
+    if (sighashType !== hashType) {
+      throw new Error('Signature sighash does not match input sighash type');
+    }
+  });
+}
+
 function checkScriptForPubkey(
   pubkey: Buffer,
   script: Buffer,