Merge #14039: Disallow extended encoding for non-witness transactions

bb530efa18 Disallow extended encoding for non-witness transactions (Pieter Wuille)

Pull request description:

  BIP144 specifies that transactions without witness should use the legacy encoding, which is currently not enforced.

  This rule was present in the original SegWit implementation (https://github.com/bitcoin/bitcoin/pull/8149), but was subsequently dropped (https://github.com/bitcoin/bitcoin/pull/8589).

  As all hashes, txids, and weights are always computed over a reserialized version of a transaction, it is mostly harmless to permit extended encoding for non-segwit transactions, but I'd rather strictly follow the BIP.

ACKs for commit bb530e:
  instagibbs:
    utACK bb530efa18
  stevenroose:
    utACK bb530efa18

Tree-SHA512: 1aeccd6a555f43784fefb076ce2e8ad2f5ba7be49840544a50050d0390f82373f87201bf56cf8bb30841b4f9cd893b382261a080da875d4e11ab7051f8640dbe
This commit is contained in:
MarcoFalke 2019-04-25 14:15:40 -04:00
commit c65c77c721
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@ -222,6 +222,10 @@ 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 */