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Diffstat (limited to 'src/test/validation_tests.cpp')
| -rw-r--r-- | src/test/validation_tests.cpp | 216 |
1 files changed, 216 insertions, 0 deletions
diff --git a/src/test/validation_tests.cpp b/src/test/validation_tests.cpp index 0b4c491615..c9b9671671 100644 --- a/src/test/validation_tests.cpp +++ b/src/test/validation_tests.cpp @@ -4,11 +4,16 @@ #include <chainparams.h> #include <consensus/amount.h> +#include <consensus/merkle.h> +#include <core_io.h> +#include <hash.h> #include <net.h> #include <signet.h> #include <uint256.h> #include <validation.h> +#include <string> + #include <test/util/setup_common.h> #include <boost/test/unit_test.hpp> @@ -144,4 +149,215 @@ BOOST_AUTO_TEST_CASE(test_assumeutxo) BOOST_CHECK_EQUAL(out210.nChainTx, 200U); } +BOOST_AUTO_TEST_CASE(block_malleation) +{ + // Test utilities that calls `IsBlockMutated` and then clears the validity + // cache flags on `CBlock`. + auto is_mutated = [](CBlock& block, bool check_witness_root) { + bool mutated{IsBlockMutated(block, check_witness_root)}; + block.fChecked = false; + block.m_checked_witness_commitment = false; + block.m_checked_merkle_root = false; + return mutated; + }; + auto is_not_mutated = [&is_mutated](CBlock& block, bool check_witness_root) { + return !is_mutated(block, check_witness_root); + }; + + // Test utilities to create coinbase transactions and insert witness + // commitments. + // + // Note: this will not include the witness stack by default to avoid + // triggering the "no witnesses allowed for blocks that don't commit to + // witnesses" rule when testing other malleation vectors. + auto create_coinbase_tx = [](bool include_witness = false) { + CMutableTransaction coinbase; + coinbase.vin.resize(1); + if (include_witness) { + coinbase.vin[0].scriptWitness.stack.resize(1); + coinbase.vin[0].scriptWitness.stack[0] = std::vector<unsigned char>(32, 0x00); + } + + coinbase.vout.resize(1); + coinbase.vout[0].scriptPubKey.resize(MINIMUM_WITNESS_COMMITMENT); + coinbase.vout[0].scriptPubKey[0] = OP_RETURN; + coinbase.vout[0].scriptPubKey[1] = 0x24; + coinbase.vout[0].scriptPubKey[2] = 0xaa; + coinbase.vout[0].scriptPubKey[3] = 0x21; + coinbase.vout[0].scriptPubKey[4] = 0xa9; + coinbase.vout[0].scriptPubKey[5] = 0xed; + + auto tx = MakeTransactionRef(coinbase); + assert(tx->IsCoinBase()); + return tx; + }; + auto insert_witness_commitment = [](CBlock& block, uint256 commitment) { + assert(!block.vtx.empty() && block.vtx[0]->IsCoinBase() && !block.vtx[0]->vout.empty()); + + CMutableTransaction mtx{*block.vtx[0]}; + CHash256().Write(commitment).Write(std::vector<unsigned char>(32, 0x00)).Finalize(commitment); + memcpy(&mtx.vout[0].scriptPubKey[6], commitment.begin(), 32); + block.vtx[0] = MakeTransactionRef(mtx); + }; + + { + CBlock block; + + // Empty block is expected to have merkle root of 0x0. + BOOST_CHECK(block.vtx.empty()); + block.hashMerkleRoot = uint256{1}; + BOOST_CHECK(is_mutated(block, /*check_witness_root=*/false)); + block.hashMerkleRoot = uint256{}; + BOOST_CHECK(is_not_mutated(block, /*check_witness_root=*/false)); + + // Block with a single coinbase tx is mutated if the merkle root is not + // equal to the coinbase tx's hash. + block.vtx.push_back(create_coinbase_tx()); + BOOST_CHECK(block.vtx[0]->GetHash() != block.hashMerkleRoot); + BOOST_CHECK(is_mutated(block, /*check_witness_root=*/false)); + block.hashMerkleRoot = block.vtx[0]->GetHash(); + BOOST_CHECK(is_not_mutated(block, /*check_witness_root=*/false)); + + // Block with two transactions is mutated if the merkle root does not + // match the double sha256 of the concatenation of the two transaction + // hashes. + block.vtx.push_back(MakeTransactionRef(CMutableTransaction{})); + BOOST_CHECK(is_mutated(block, /*check_witness_root=*/false)); + HashWriter hasher; + hasher.write(Span(reinterpret_cast<const std::byte*>(block.vtx[0]->GetHash().data()), 32)); + hasher.write(Span(reinterpret_cast<const std::byte*>(block.vtx[1]->GetHash().data()), 32)); + block.hashMerkleRoot = hasher.GetHash(); + BOOST_CHECK(is_not_mutated(block, /*check_witness_root=*/false)); + + // Block with two transactions is mutated if any node is duplicate. + { + block.vtx[1] = block.vtx[0]; + BOOST_CHECK(is_mutated(block, /*check_witness_root=*/false)); + HashWriter hasher; + hasher.write(Span(reinterpret_cast<const std::byte*>(block.vtx[0]->GetHash().data()), 32)); + hasher.write(Span(reinterpret_cast<const std::byte*>(block.vtx[1]->GetHash().data()), 32)); + block.hashMerkleRoot = hasher.GetHash(); + BOOST_CHECK(is_mutated(block, /*check_witness_root=*/false)); + } + + // Blocks with 64-byte coinbase transactions are not considered mutated + block.vtx.clear(); + { + CMutableTransaction mtx; + mtx.vin.resize(1); + mtx.vout.resize(1); + mtx.vout[0].scriptPubKey.resize(4); + block.vtx.push_back(MakeTransactionRef(mtx)); + block.hashMerkleRoot = block.vtx.back()->GetHash(); + assert(block.vtx.back()->IsCoinBase()); + assert(GetSerializeSize(block.vtx.back(), PROTOCOL_VERSION | SERIALIZE_TRANSACTION_NO_WITNESS) == 64); + } + BOOST_CHECK(is_not_mutated(block, /*check_witness_root=*/false)); + } + + { + // Test merkle root malleation + + // Pseudo code to mine transactions tx{1,2,3}: + // + // ``` + // loop { + // tx1 = random_tx() + // tx2 = random_tx() + // tx3 = deserialize_tx(txid(tx1) || txid(tx2)); + // if serialized_size_without_witness(tx3) == 64 { + // print(hex(tx3)) + // break + // } + // } + // ``` + // + // The `random_tx` function used to mine the txs below simply created + // empty transactions with a random version field. + CMutableTransaction tx1; + BOOST_CHECK(DecodeHexTx(tx1, "ff204bd0000000000000", /*try_no_witness=*/true, /*try_witness=*/false)); + CMutableTransaction tx2; + BOOST_CHECK(DecodeHexTx(tx2, "8ae53c92000000000000", /*try_no_witness=*/true, /*try_witness=*/false)); + CMutableTransaction tx3; + BOOST_CHECK(DecodeHexTx(tx3, "cdaf22d00002c6a7f848f8ae4d30054e61dcf3303d6fe01d282163341f06feecc10032b3160fcab87bdfe3ecfb769206ef2d991b92f8a268e423a6ef4d485f06", /*try_no_witness=*/true, /*try_witness=*/false)); + { + // Verify that double_sha256(txid1||txid2) == txid3 + HashWriter hasher; + hasher.write(Span(reinterpret_cast<const std::byte*>(tx1.GetHash().data()), 32)); + hasher.write(Span(reinterpret_cast<const std::byte*>(tx2.GetHash().data()), 32)); + assert(hasher.GetHash() == tx3.GetHash()); + // Verify that tx3 is 64 bytes in size (without witness). + assert(GetSerializeSize(tx3, PROTOCOL_VERSION | SERIALIZE_TRANSACTION_NO_WITNESS) == 64); + } + + CBlock block; + block.vtx.push_back(MakeTransactionRef(tx1)); + block.vtx.push_back(MakeTransactionRef(tx2)); + uint256 merkle_root = block.hashMerkleRoot = BlockMerkleRoot(block); + BOOST_CHECK(is_not_mutated(block, /*check_witness_root=*/false)); + + // Mutate the block by replacing the two transactions with one 64-byte + // transaction that serializes into the concatenation of the txids of + // the transactions in the unmutated block. + block.vtx.clear(); + block.vtx.push_back(MakeTransactionRef(tx3)); + BOOST_CHECK(!block.vtx.back()->IsCoinBase()); + BOOST_CHECK(BlockMerkleRoot(block) == merkle_root); + BOOST_CHECK(is_mutated(block, /*check_witness_root=*/false)); + } + + { + CBlock block; + block.vtx.push_back(create_coinbase_tx(/*include_witness=*/true)); + { + CMutableTransaction mtx; + mtx.vin.resize(1); + mtx.vin[0].scriptWitness.stack.resize(1); + mtx.vin[0].scriptWitness.stack[0] = {0}; + block.vtx.push_back(MakeTransactionRef(mtx)); + } + block.hashMerkleRoot = BlockMerkleRoot(block); + // Block with witnesses is considered mutated if the witness commitment + // is not validated. + BOOST_CHECK(is_mutated(block, /*check_witness_root=*/false)); + // Block with invalid witness commitment is considered mutated. + BOOST_CHECK(is_mutated(block, /*check_witness_root=*/true)); + + // Block with valid commitment is not mutated + { + auto commitment{BlockWitnessMerkleRoot(block)}; + insert_witness_commitment(block, commitment); + block.hashMerkleRoot = BlockMerkleRoot(block); + } + BOOST_CHECK(is_not_mutated(block, /*check_witness_root=*/true)); + + // Malleating witnesses should be caught by `IsBlockMutated`. + { + CMutableTransaction mtx{*block.vtx[1]}; + assert(!mtx.vin[0].scriptWitness.stack[0].empty()); + ++mtx.vin[0].scriptWitness.stack[0][0]; + block.vtx[1] = MakeTransactionRef(mtx); + } + // Without also updating the witness commitment, the merkle root should + // not change when changing one of the witnesses. + BOOST_CHECK(block.hashMerkleRoot == BlockMerkleRoot(block)); + BOOST_CHECK(is_mutated(block, /*check_witness_root=*/true)); + { + auto commitment{BlockWitnessMerkleRoot(block)}; + insert_witness_commitment(block, commitment); + block.hashMerkleRoot = BlockMerkleRoot(block); + } + BOOST_CHECK(is_not_mutated(block, /*check_witness_root=*/true)); + + // Test malleating the coinbase witness reserved value + { + CMutableTransaction mtx{*block.vtx[0]}; + mtx.vin[0].scriptWitness.stack.resize(0); + block.vtx[0] = MakeTransactionRef(mtx); + block.hashMerkleRoot = BlockMerkleRoot(block); + } + BOOST_CHECK(is_mutated(block, /*check_witness_root=*/true)); + } +} + BOOST_AUTO_TEST_SUITE_END() |