test(dash): S8 job-notify round-trip KAT — merkle branch binds coinbase to canonical root

.github/workflows/build.yml

@@ -103,7 +103,7 @@ jobs:
                     test_threading test_weights \
                     test_header_chain test_mempool test_template_builder \
                     test_doge_chain test_compact_blocks test_dash_x11_kat \
-                    test_dash_header_chain test_dash_block_replay test_dash_conformance test_dash_subsidy test_dash_mempool test_dash_simplifiedmns test_dash_quorum test_dash_quorum_root test_dash_mn_state test_dash_embedded_gbt test_dash_smldiff test_dash_p2p_messages test_dash_p2p_connection test_dash_p2p_node test_dash_node_interface test_dash_config test_dash_broadcaster test_dash_broadcaster_full test_dash_share_hash_link test_dash_block_relay test_dash_rpc_request test_dash_rpc_conf test_dash_block_producer test_dash_embedded_relay_e2e test_dash_block_relay_plan test_dash_version_activation_latch test_dash_block_relay_binding test_dash_block_relay_dual_arm test_dash_coinbase_parity test_dash_donation_combined test_dash_g3_assembled test_dash_work_target test_dash_work_job_targets test_dash_stratum_binding test_dash_cb_payee test_dash_stratum_notify_roundtrip test_dash_poolnode_messages test_dash_peer test_dash_share_tracker test_dash_node test_dash_share_messages test_dash_stratum_extranonce_split \
+                    test_dash_header_chain test_dash_block_replay test_dash_conformance test_dash_subsidy test_dash_mempool test_dash_simplifiedmns test_dash_quorum test_dash_quorum_root test_dash_mn_state test_dash_embedded_gbt test_dash_smldiff test_dash_p2p_messages test_dash_p2p_connection test_dash_p2p_node test_dash_node_interface test_dash_config test_dash_broadcaster test_dash_broadcaster_full test_dash_share_hash_link test_dash_block_relay test_dash_rpc_request test_dash_rpc_conf test_dash_block_producer test_dash_embedded_relay_e2e test_dash_block_relay_plan test_dash_version_activation_latch test_dash_block_relay_binding test_dash_block_relay_dual_arm test_dash_coinbase_parity test_dash_donation_combined test_dash_g3_assembled test_dash_work_target test_dash_work_job_targets test_dash_stratum_binding test_dash_job_notify_roundtrip test_dash_cb_payee test_dash_stratum_notify_roundtrip test_dash_poolnode_messages test_dash_peer test_dash_share_tracker test_dash_node test_dash_share_messages test_dash_stratum_extranonce_split \
                     test_multiaddress_pplns test_pplns_stress \
                     test_hash_link test_decay_pplns \
                     test_pplns_consensus \
@@ -253,7 +253,7 @@ jobs:
                     test_threading test_weights \
                     test_header_chain test_mempool test_template_builder \
                     test_doge_chain test_compact_blocks test_dash_x11_kat \
-                    test_dash_header_chain test_dash_block_replay test_dash_conformance test_dash_subsidy test_dash_mempool test_dash_simplifiedmns test_dash_quorum test_dash_quorum_root test_dash_mn_state test_dash_embedded_gbt test_dash_smldiff test_dash_p2p_messages test_dash_p2p_connection test_dash_p2p_node test_dash_node_interface test_dash_config test_dash_broadcaster test_dash_broadcaster_full test_dash_share_hash_link test_dash_block_relay test_dash_rpc_request test_dash_rpc_conf test_dash_block_producer test_dash_embedded_relay_e2e test_dash_block_relay_plan test_dash_version_activation_latch test_dash_block_relay_binding test_dash_block_relay_dual_arm test_dash_coinbase_parity test_dash_donation_combined test_dash_g3_assembled test_dash_work_target test_dash_work_job_targets test_dash_stratum_binding test_dash_cb_payee test_dash_stratum_notify_roundtrip test_dash_poolnode_messages test_dash_peer test_dash_share_tracker test_dash_node test_dash_share_messages test_dash_stratum_extranonce_split \
+                    test_dash_header_chain test_dash_block_replay test_dash_conformance test_dash_subsidy test_dash_mempool test_dash_simplifiedmns test_dash_quorum test_dash_quorum_root test_dash_mn_state test_dash_embedded_gbt test_dash_smldiff test_dash_p2p_messages test_dash_p2p_connection test_dash_p2p_node test_dash_node_interface test_dash_config test_dash_broadcaster test_dash_broadcaster_full test_dash_share_hash_link test_dash_block_relay test_dash_rpc_request test_dash_rpc_conf test_dash_block_producer test_dash_embedded_relay_e2e test_dash_block_relay_plan test_dash_version_activation_latch test_dash_block_relay_binding test_dash_block_relay_dual_arm test_dash_coinbase_parity test_dash_donation_combined test_dash_g3_assembled test_dash_work_target test_dash_work_job_targets test_dash_stratum_binding test_dash_job_notify_roundtrip test_dash_cb_payee test_dash_stratum_notify_roundtrip test_dash_poolnode_messages test_dash_peer test_dash_share_tracker test_dash_node test_dash_share_messages test_dash_stratum_extranonce_split \
                     test_hash_link test_decay_pplns \
                     test_pplns_consensus \
                     test_v36_script_sorting test_v36_cross_impl_refhash \

test/CMakeLists.txt

@@ -317,6 +317,15 @@ if (BUILD_TESTING AND GTest_FOUND)
     )
     target_link_libraries(test_dash_work_job_targets PRIVATE c2pool_payout c2pool_hashrate c2pool_merged_mining)  # OBJECT-lib SCC direct-naming (#22/#39): core stratum/web_server TUs
     gtest_add_tests(test_dash_work_job_targets "" AUTO)
+    add_executable(test_dash_job_notify_roundtrip test_dash_job_notify_roundtrip.cpp)
+    target_link_libraries(test_dash_job_notify_roundtrip PRIVATE
+        GTest::gtest_main GTest::gtest
+        dash_x11 core
+        nlohmann_json::nlohmann_json
+        ${Boost_LIBRARIES}
+    )
+    target_link_libraries(test_dash_job_notify_roundtrip PRIVATE c2pool_payout c2pool_hashrate c2pool_merged_mining)  # OBJECT-lib SCC direct-naming (#22/#39)
+    gtest_add_tests(test_dash_job_notify_roundtrip "" AUTO)
 
     add_executable(test_dash_share_messages test_dash_share_messages.cpp)
     target_link_libraries(test_dash_share_messages PRIVATE

test/test_dash_job_notify_roundtrip.cpp

@@ -0,0 +1,215 @@
+// DASH S8 STRATUM-BINDING contract KAT -- job-notify ROUND-TRIP leaf.
+//
+// The final leaf of the S8 stratum-binding suite. Where test_dash_stratum_binding
+// pins the coinbase NONCE slot geometry (the get_work()->job half) and
+// test_dash_work_job_targets pins the job TARGET arithmetic, THIS pins the
+// notify->submit seam: the merkle_branch the pool sends ONCE per job must fold
+// the miner's reassembled coinbase back to the SAME canonical merkle root the
+// pool computes over the full tx list. That equality is the whole reason a
+// miner can iterate extranonce2 locally without re-fetching the job -- if the
+// branch did not bind, every submit would carry a root the pool rejects.
+//
+// ORACLE: frstrtr/p2pool-dash @9a0a609
+//   dash/stratum.py  -- mining.notify packs merkle branch as
+//        [pack.IntType(256).pack(s).encode('hex') for s in link.branch]
+//        i.e. LE internal bytes as hex (NOT the reversed display form).
+//   p2pool/work.py   -- coinb1/coinb2 split at the nonce64 slot (:421,:436-437).
+// Every expected value below is derived from an INDEPENDENT Python sha256d
+// merkle walk (see the golden block), NOT from the SUT: a true byte-parity pin.
+//
+// Pure / socket-free / node-free: synthetic coinbase + synthetic sibling tx
+// hashes, no dashd, no live sharechain, no template build. The round-trip
+// invariant stands alone from generate_transaction / the stratum server.
+
+#include <gtest/gtest.h>
+
+#include <cstddef>
+#include <cstring>
+#include <numeric>
+#include <span>
+#include <string>
+#include <vector>
+
+#include <impl/dash/coinbase_builder.hpp>  // split_coinb, merkle_branches_raw/hex, sha256d, EXTRANONCE2_SIZE
+#include <btclibs/util/strencodings.h>     // HexStr
+#include <core/uint256.hpp>
+
+using dash::coinbase::CoinbaseLayout;
+using dash::coinbase::CoinbSplit;
+using dash::coinbase::split_coinb;
+using dash::coinbase::sha256d;
+using dash::coinbase::merkle_branches_raw;
+using dash::coinbase::merkle_branches_hex;
+using dash::coinbase::EXTRANONCE2_SIZE;
+
+namespace {
+
+// Synthetic 40-byte coinbase identical to test_dash_stratum_binding: bytes[i]=i
+// with the 8-byte nonce64 slot at [28,36) zeroed. (Leaf0 goldens below MATCH
+// that sibling test, confirming a shared layout.)
+constexpr size_t kTotal  = 40;
+constexpr size_t kOffset = 28;   // = kTotal - 4 - 8
+
+CoinbaseLayout make_layout()
+{
+    CoinbaseLayout lay;
+    lay.bytes.resize(kTotal);
+    std::iota(lay.bytes.begin(), lay.bytes.end(), static_cast<unsigned char>(0));
+    for (size_t i = kOffset; i < kOffset + EXTRANONCE2_SIZE; ++i)
+        lay.bytes[i] = 0x00;
+    lay.nonce64_offset  = kOffset;
+    lay.ref_hash_offset = kOffset - 32;
+    return lay;
+}
+
+std::vector<unsigned char> reassemble(const CoinbaseLayout& lay,
+                                      std::span<const unsigned char> e2)
+{
+    std::vector<unsigned char> cb;
+    cb.reserve(lay.bytes.size());
+    cb.insert(cb.end(), lay.bytes.begin(), lay.bytes.begin() + lay.nonce64_offset);
+    cb.insert(cb.end(), e2.begin(), e2.end());
+    cb.insert(cb.end(), lay.bytes.begin() + lay.nonce64_offset + EXTRANONCE2_SIZE,
+              lay.bytes.end());
+    return cb;
+}
+
+uint256 hash_of(const std::vector<unsigned char>& b)
+{
+    return sha256d(std::span<const unsigned char>(b.data(), b.size()));
+}
+
+// Synthetic sibling tx hashes (indices 1..3 of the merkle tree). Values are
+// arbitrary but fixed; the Python oracle uses the same sha256d(bytes([v]*4)).
+uint256 mk_tx(unsigned char v)
+{
+    std::vector<unsigned char> b(4, v);
+    return sha256d(std::span<const unsigned char>(b.data(), b.size()));
+}
+
+// Pool-side canonical merkle root over [coinbase_leaf, h1, h2, h3] -- computed
+// in-test, independent of merkle_branches_raw, so the round-trip check is not a
+// tautology against the SUT branch.
+uint256 canonical_root(uint256 leaf0, uint256 h1, uint256 h2, uint256 h3)
+{
+    std::vector<uint256> layer{leaf0, h1, h2, h3};
+    while (layer.size() > 1) {
+        if (layer.size() % 2 == 1) layer.push_back(layer.back());
+        std::vector<uint256> next;
+        for (size_t i = 0; i + 1 < layer.size(); i += 2) {
+            std::vector<unsigned char> buf(64);
+            std::memcpy(buf.data(),      layer[i].data(),     32);
+            std::memcpy(buf.data() + 32, layer[i + 1].data(), 32);
+            next.push_back(sha256d(std::span<const unsigned char>(buf.data(), buf.size())));
+        }
+        layer.swap(next);
+    }
+    return layer[0];
+}
+
+// Miner-side walk: fold the coinbase leaf through the branch siblings, exactly
+// as cpuminer does with the mining.notify merkle_branch. root = leaf; for each
+// sibling s: root = sha256d(root || s).
+uint256 miner_root(uint256 leaf0, const std::vector<uint256>& branch)
+{
+    uint256 r = leaf0;
+    for (const auto& s : branch) {
+        std::vector<unsigned char> buf(64);
+        std::memcpy(buf.data(),      r.data(), 32);
+        std::memcpy(buf.data() + 32, s.data(), 32);
+        r = sha256d(std::span<const unsigned char>(buf.data(), buf.size()));
+    }
+    return r;
+}
+
+const unsigned char E2_A[8]    = {1, 2, 3, 4, 5, 6, 7, 8};
+const unsigned char E2_B[8]    = {0xde, 0xad, 0xbe, 0xef, 0xca, 0xfe, 0xf0, 0x0d};
+const unsigned char E2_ZERO[8] = {0, 0, 0, 0, 0, 0, 0, 0};
+
+// The branch the pool computes ONCE per job, from the placeholder coinbase
+// (slot 0 == zero-hash) plus the three sibling tx hashes. Siblings are
+// independent of leaf 0, which is exactly what makes the branch reusable.
+std::vector<uint256> job_branch()
+{
+    std::vector<uint256> leaves{uint256::ZERO, mk_tx(0xa1), mk_tx(0xb2), mk_tx(0xc3)};
+    return merkle_branches_raw(leaves);
+}
+
+}  // namespace
+
+// (1) The notify branch has the expected depth for a 4-leaf tree: two siblings
+//     (one per merkle level). A wrong-depth branch silently mis-binds.
+TEST(DashJobNotifyRoundTrip, BranchDepth)
+{
+    EXPECT_EQ(job_branch().size(), static_cast<size_t>(2));
+}
+
+// (2) ROUND-TRIP core: for the zero extranonce2 (identity), the miner walk over
+//     the notify branch reproduces the pool canonical root byte-for-byte.
+TEST(DashJobNotifyRoundTrip, ZeroNonceRootMatches)
+{
+    CoinbaseLayout lay = make_layout();
+    uint256 h1 = mk_tx(0xa1), h2 = mk_tx(0xb2), h3 = mk_tx(0xc3);
+    uint256 leaf0 = hash_of(reassemble(lay, std::span<const unsigned char>(E2_ZERO, 8)));
+    EXPECT_EQ(miner_root(leaf0, job_branch()), canonical_root(leaf0, h1, h2, h3));
+}
+
+// (3) ROUND-TRIP under extranonce2 iteration: the SAME job branch binds every
+//     distinct extranonce2 back to the matching canonical root -- the miner
+//     iterates the slot without re-fetching the job.
+TEST(DashJobNotifyRoundTrip, IteratedNonceRootMatches)
+{
+    CoinbaseLayout lay = make_layout();
+    uint256 h1 = mk_tx(0xa1), h2 = mk_tx(0xb2), h3 = mk_tx(0xc3);
+    const std::vector<uint256> br = job_branch();
+    for (const auto* e2 : {E2_A, E2_B}) {
+        uint256 leaf0 = hash_of(reassemble(lay, std::span<const unsigned char>(e2, 8)));
+        EXPECT_EQ(miner_root(leaf0, br), canonical_root(leaf0, h1, h2, h3));
+    }
+}
+
+// (4) Distinct extranonce2 -> distinct block merkle root: the notify branch
+//     PARTITIONS the search space rather than collapsing it (overlapping roots
+//     would let two miners claim one solution).
+TEST(DashJobNotifyRoundTrip, RootInjectivity)
+{
+    CoinbaseLayout lay = make_layout();
+    const std::vector<uint256> br = job_branch();
+    uint256 r0 = miner_root(hash_of(reassemble(lay, std::span<const unsigned char>(E2_ZERO, 8))), br);
+    uint256 rA = miner_root(hash_of(reassemble(lay, std::span<const unsigned char>(E2_A, 8))), br);
+    uint256 rB = miner_root(hash_of(reassemble(lay, std::span<const unsigned char>(E2_B, 8))), br);
+    EXPECT_NE(rA, rB);
+    EXPECT_NE(rA, r0);
+    EXPECT_NE(rB, r0);
+}
+
+// (5) Wire form of the merkle branch is LE internal-bytes hex (stratum.py
+//     convention), NOT the reversed display form. Golden hex from independent
+//     Python (pack.IntType(256).pack(s).encode(hex)).
+TEST(DashJobNotifyRoundTrip, BranchWireHexGolden)
+{
+    std::vector<std::string> hex = merkle_branches_hex(job_branch());
+    ASSERT_EQ(hex.size(), static_cast<size_t>(2));
+    EXPECT_EQ(hex[0], "f8401cfffc19b3a56c2de52278297152d9028b4efbc30f8d2096f780ceb0b2b6");
+    EXPECT_EQ(hex[1], "6f43268501a527c6adc37e7d6a293168c42f9aae863ab15628ab78ddf9ec836c");
+}
+
+// (6) Golden merkle-root byte-parity anchors (GetHex display form), computed
+//     independently in Python over [sha256d(coinbase_e2), h1, h2, h3]:
+//       h_i   = sha256d(bytes([0xa1/0xb2/0xc3]*4))
+//       leaf0 = sha256d(base[:28] + e2 + base[36:]),  base = bytes(range(40)) w/ [28:36]=0
+TEST(DashJobNotifyRoundTrip, CanonicalRootGolden)
+{
+    CoinbaseLayout lay = make_layout();
+    uint256 h1 = mk_tx(0xa1), h2 = mk_tx(0xb2), h3 = mk_tx(0xc3);
+    auto root_for = [&](const unsigned char* e2) {
+        return canonical_root(
+            hash_of(reassemble(lay, std::span<const unsigned char>(e2, 8))), h1, h2, h3);
+    };
+    EXPECT_EQ(root_for(E2_ZERO).GetHex(),
+              "b4bfbae433a5f984c30f4bead3cfe650a0e770bd8126b5c16a15b4b5b9243189");
+    EXPECT_EQ(root_for(E2_A).GetHex(),
+              "d445471556d06a5b2722c27f92498bf030117d756fd8fe7997d3732cf4df5e93");
+    EXPECT_EQ(root_for(E2_B).GetHex(),
+              "7c81c0a061417d008d0ada06bfe98d69d82ea6561ec1c327f7fb34d63259772c");
+}