A single getblockstrm request makes a peer stream a contiguous range of old
blocks back-to-back as ordinary BLOCK messages, amortizing the per-block
round-trip over the whole range instead of the MAX_BLOCKS_IN_TRANSIT_PER_PEER
window. This targets the bandwidth-delay-product ceiling that dominates IBD
from few/high-latency peers below the checkpoint.
Design (off by default; negotiated via a NODE_BULKBLOCKS service bit; the
default getdata IBD path is untouched when disabled):
- protocol: NODE_BULKBLOCKS service bit + getblockstrm/blockstream messages.
- requester: in SendMessages, after FindNextBlocksToDownload, when the first
needed block is >= BULK_TIP_MARGIN (5000) below the network tip and the peer
advertises the bit and we are in IBD, request a contiguous range (<=128
blocks) instead of per-block getdata; mark the range in-flight.
- server: stream the range (caps 128 blocks / 8 MiB; reads outside cs_main;
per-peer flood throttle), then a trailing blockstream header with the actual
count sent. Self-suppresses while the server itself is in IBD.
- received blocks ride the existing BLOCK -> ProcessNewBlock path (fully
validated; checkpoints below 2.84M still apply); the trailing header
reconciles partial deliveries and the range is freed on a 90s timeout, so a
partial/withheld/refused batch falls back to the normal path (no leak, no
permanent gap, no disconnect). In-flight tracking is by literal hash, so a
reorg cannot orphan range entries.
Hardened against the issues found in two adversarial review passes (drain vs
timeout, partial reconciliation, ownership-guarded frees, one-shot header,
reorg-proof helpers, cs_main hold). Validated end-to-end between two local
v1.0.3 nodes (128/128 and partial serves; height advanced; no errors).
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
The per-peer in-flight block window (MAX_BLOCKS_IN_TRANSIT_PER_PEER) was a
hardcoded 16. On a single, high-latency peer during IBD the transfer is
bandwidth-delay-product bound (window / RTT), so with tiny sub-checkpoint
blocks the window, not bandwidth, is the ceiling — measured ~4x throughput
going 16 -> 64 on a 350ms-RTT peer. Make it a runtime flag (default 16,
clamped 1..4096), logged at startup. No behavior change at the default.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
LIBBITCOIN_SERVER was fed into both EXTRA_LIBRARIES (a list of buildable
library files) and several _LDADD link lines. Embedding the -lcurl linker
flag inside it made automake reject it in the EXTRA_LIBRARIES context
("'-lcurl' is not a standard library name"). Make LIBBITCOIN_SERVER a pure
file and route -lcurl through its own LIBCURL variable, added to the
dragonxd, hush-gtest, and test_bitcoin link lines after libbitcoin_server.a
(whose objects reference curl symbols) so static link order stays correct.
Verified with a clean Windows cross-build (-DCURL_STATICLIB) and a native
Linux build: both link cleanly and the automake lint is gone.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Wallets upgraded across the 1.0.1->1.0.2 network transition could end up
with note witnesses stuck at a stale height, causing z_sendmany /
z_mergetoaddress to fail to build a valid spend. Root cause was a trio of
issues that let a desynced witnessHeight perpetuate instead of self-healing:
- DecrementNoteWitnesses left witnessRootValidated and the witness deque in
an asymmetric state on the size<=1 path.
- VerifyAndSetInitialWitness blindly trusted witnessHeight instead of
validating the cached root against the chain, so a bad height survived.
- UpdatedNoteData copied witnessHeight even when no witnesses were present.
- witnessRootValidated was uninitialized and never serialized, so a garbage
true value could short-circuit the self-heal.
Fixes:
- Default witnessRootValidated to false (in-memory only; never serialized).
- VerifyAndSetInitialWitness now validates the cached witness root against
the block's hashFinalSaplingRoot and reseeds on mismatch.
- Symmetric reset of witness state in DecrementNoteWitnesses.
- Guard the witnessHeight copy in UpdatedNoteData behind a non-empty
witnesses check.
- Defensive majority-root guard in GetSaplingNoteWitnesses.
Also rewrites BuildWitnessCache to rebuild the witness cache in parallel
(per-block commitment extraction + worker pool), cutting a full repair from
~28 min to ~2 min. Tunable via -witnessbuildthreads and -witnessfastrebuild;
output verified byte-identical to the serial path.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
- Parallel RandomX PoW pre-verification pool (CCheckQueue) run ahead of the serial
connect; consensus-neutral (inline CheckRandomXSolution fallback still verifies
anything not pre-verified). New -randomxverifythreads (default = -par).
- Adaptive dbcache: default sizes the UTXO/coins cache to most of RAM and shrinks
under memory pressure, always leaving a reserve free; -dbcache pins a fixed value.
- P2P block download: bounded socket recv-drain loop (tlsmanager); frontier-block
reassignment to break head-of-line stalls (-blockreassigntimeout); ProcessGetData
serves a bounded batch of blocks per pass instead of one (fixes the serve-side
one-block-per-tick throttle that caps download network-wide).
- assumeutxo: dumptxoutset RPC + LoadSnapshot machinery + AssumeutxoData chainparams.
- Signed bootstrap verification (util/bootstrap-dragonx.sh, util/sign-bootstrap.md).
- gtest: RandomX pre-verify consensus-equivalence test + UTXO-snapshot round-trip;
revived the gtest harness (Makefile.am include fix, Makefile.gtest.include).
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
During Initial Block Download, block data may not be flushed to disk
when the wallet notification thread tries to read it. Instead of
crashing with a fatal error, log a message and retry on the next cycle.
- Update compiler references from gcc-8 to gcc-15 across build system
(build-mac.sh, darwin.mk, Makefile_custom)
- Use system Rust (rustup) instead of bundled Rust 1.32.0 for librustzcash
to fix rlib linker incompatibility on macOS Sequoia
- Replace deprecated std::random_shuffle with std::shuffle (net.cpp,
transaction_builder.cpp, wallet.cpp)
- Fix -std=gnu17 -> -std=gnu++17 for C++ targets (libzcash, libhush)
- Fix nodiscard warning in glibcxx_sanity.cpp
- Replace deprecated OSMemoryBarrier with std::atomic_thread_fence in LevelDB
- Add -Wno-error=deprecated-declarations to CXXFLAGS for third-party headers
- Fix REMAINING_ARGS unbound variable in build.sh
- Add --disable-tests handling to build-mac.sh
- Update README with correct macOS build dependencies and instructions
Lower SPROUT_VALUE_VERSION and SAPLING_VALUE_VERSION constants in
chain.h from upstream Zcash values (1001400/1010100) to 1000000.
When DragonX was rebranded from HUSH3, CLIENT_VERSION was reset from
3.10.5 to 1.0.0, falling below these thresholds. This caused
nSaplingValue to silently skip serialization, so the sapling pool
total reset to 0 on every node restart. Explorer nodes should reindex
once after upgrading.
Add subsidy and fees fields to the getblock RPC response so explorers
can display the correct 3 DRGX block reward separately from fees,
instead of showing the combined coinbase output as the reward.
Fresh-syncing nodes rejected the on-chain min-diff block at the
RANDOMX_VALIDATION activation height (2838976) because GetNextWorkRequired
computed the expected nBits from the preceding normal-difficulty blocks,
producing 469847994 instead of the on-chain 0x200f0f0f (HUSH_MINDIFF_NBITS).
This caused all seed nodes to be banned with "Incorrect diffbits" and the
node could never sync past that height.
Two changes:
1. GetNextWorkRequired (pow.cpp): Return nProofOfWorkLimit at the exact
RANDOMX_VALIDATION activation height, matching the on-chain diff reset.
2. ContextualCheckBlockHeader (main.cpp): Raise DragonX daaForkHeight to
RANDOMX_VALIDATION + 62000, covering the window where nBits was never
validated (diff reset at 2838976 through the attack at ~2879907).
Tested by invalidating block 2838975 and reconsidering — node re-validated
through the diff reset and attack window, syncing back to tip with zero
bad-diffbits rejections.
Bump version to 1.0.1.
Two critical vulnerabilities allowed an attacker to flood the DragonX chain
with minimum-difficulty blocks starting at height 2879907:
1. ContextualCheckBlockHeader only validated nBits for HUSH3 mainnet
(gated behind `if (ishush3)`), never for HAC/smart chains. An attacker
could submit blocks claiming any difficulty and the node accepted them.
Add nBits validation for all non-HUSH3 smart chains, gated above
daaForkHeight (default 450000) to maintain consensus with early chain
history that was mined by a different binary.
2. The rebrand commit (85c8d7f7d) commented out the `return false` block
in CheckProofOfWork that rejects blocks whose hash does not meet the
claimed target. This made PoW validation a no-op — any hash passed.
Restore the rejection block and add RANDOMX_VALIDATION height-gated
logic so blocks after the activation height are always validated even
during initial block loading.
Vulnerability #1 was inherited from the upstream hush3 codebase.
Vulnerability #2 was introduced by the DragonX rebrand.
Minimal rebrand (see compliant-rebrand branch for full rebrand):
- Rename binaries: hushd/hush-cli/hush-tx → dragonxd/dragonx-cli/dragonx-tx
- Default to DRAGONX chain params without -ac_* flags (randomx, blocktime=36, private=1)
- Update configure.ac: AC_INIT([DragonX],[1.0.0])
- Update client version string and user-agent to /DragonX:1.0.0/
- Add chainparams.cpp with DRAGONX network parameters
- Update build.sh, miner.cpp, pow.cpp for DragonX
- Add bootstrap-dragonx.sh utility script
- Update .gitignore for release directory
Share single RandomX dataset across all mining threads:
- Add RandomXDatasetManager with readers-writer lock, reducing RAM from
~2GB per thread to ~2GB total plus ~2MB per thread for the VM scratchpad
- Add LogProcessMemory() diagnostic helper for Linux and Windows
- Add CheckRandomXSolution() to validate RandomX PoW in nSolution field
- Add ASSETCHAINS_RANDOMX_VALIDATION activation height per chain
(DRAGONX: 2838976, TUMIN: 1200, others: height 1)
- Add CRandomXInput serializer for deterministic RandomX hash input
- Fix CheckProofOfWork() to properly reject invalid PoW (was missing
SMART_CHAIN_SYMBOL check, allowing bypass)
- Call CheckRandomXSolution() in hush_checkPOW and CheckBlockHeader
Without this fix, attackers could submit blocks with invalid RandomX
hashes that passed validation, as CheckProofOfWork returned early
during block loading and the nSolution field was never verified.
The build system supports using CC to control the C compiler
and CXX to control the c++ compiler used but src/cc was hardcoded
to use the binary "gcc". Now it respects the custom value of
$CC environment variable if it exists.
DanSandClaude Opus 4.8