Disallow coinbase output witness data, since outputs are explicit anyways

instagibbs · instagibbs · commit 2cb47d17050c · 2019-04-12T11:50:01.000-04:00
diff --git a/src/confidential_validation.cpp b/src/confidential_validation.cpp
@@ -406,6 +406,14 @@ bool VerifyAmounts(const std::vector<CTxOut>& inputs, const CTransaction& tx, st
 
 bool VerifyCoinbaseAmount(const CTransaction& tx, const CAmountMap& mapFees) {
     assert(tx.IsCoinBase());
+
+    // Miner shouldn't be stuffing witness data
+    for (const auto& outwit : tx.witness.vtxoutwit) {
+        if (!outwit.IsNull()) {
+            return false;
+        }
+    }
+
     CAmountMap remaining = mapFees;
     for (unsigned int i = 0; i < tx.vout.size(); i++) {
         const CTxOut& out = tx.vout[i];
diff --git a/test/functional/feature_txwitness.py b/test/functional/feature_txwitness.py
@@ -167,8 +167,7 @@ def WitToHex(obj):
         block_witness_stuffed = copy.deepcopy(block_struct)
 
 
-        # Add extra witness data that is covered by witness merkle root, make sure invalid until
-        # witness merkle root is recalculated
+        # Add extra witness data that is covered by witness merkle root, make sure invalid
         assert_equal(block_witness_stuffed.vtx[0].wit.vtxoutwit[0].vchSurjectionproof, b'')
         assert_equal(block_witness_stuffed.vtx[0].wit.vtxoutwit[0].vchRangeproof, b'')
         block_witness_stuffed.vtx[0].wit.vtxoutwit[0].vchRangeproof = b'\x00'*100000
@@ -180,7 +179,7 @@ def WitToHex(obj):
         block_witness_stuffed.vtx[0].rehash()
         block_witness_stuffed.hashMerkleRoot = block_witness_stuffed.calc_merkle_root()
         block_witness_stuffed.rehash()
-        self.nodes[0].testproposedblock(WitToHex(block_witness_stuffed))
+        assert_raises_rpc_error(-25, "bad-cb-amount", self.nodes[0].testproposedblock, WitToHex(block_witness_stuffed))
         assert_greater_than(len(WitToHex(block_witness_stuffed)), 100000*4) # Make sure the witness data is actually serialized
 
         # Test that issuance inputs in coinbase don't survive a serialization round-trip
