Disallow extended encoding for non-witness transactions

sipa · sipa · commit bb530efa1872 · 2018-08-23T17:15:29.000-07:00
diff --git a/src/primitives/transaction.h b/src/primitives/transaction.h
@@ -220,6 +220,10 @@ inline void UnserializeTransaction(TxType& tx, Stream& s) {
         for (size_t i = 0; i < tx.vin.size(); i++) {
             s >> tx.vin[i].scriptWitness.stack;
         }
+        if (!tx.HasWitness()) {
+            /* It's illegal to encode witnesses when all witness stacks are empty. */
+            throw std::ios_base::failure("Superfluous witness record");
+        }
     }
     if (flags) {
         /* Unknown flag in the serialization */

Original file line number	Diff line number	Diff line change
`@@ -220,6 +220,10 @@ inline void UnserializeTransaction(TxType& tx, Stream& s) {`
`220`	`220`	`for (size_t i = 0; i < tx.vin.size(); i++) {`
`221`	`221`	`s >> tx.vin[i].scriptWitness.stack;`
`222`	`222`	`}`
	`223`	`+ if (!tx.HasWitness()) {`
	`224`	`+ /* It's illegal to encode witnesses when all witness stacks are empty. */`
	`225`	`+ throw std::ios_base::failure("Superfluous witness record");`
	`226`	`+ }`
`223`	`227`	`}`
`224`	`228`	`if (flags) {`
`225`	`229`	`/* Unknown flag in the serialization */`