diff options
| -rw-r--r-- | src/main.cpp | 17 | ||||
| -rw-r--r-- | src/pow.cpp | 33 | ||||
| -rw-r--r-- | src/pow.h | 2 | ||||
| -rw-r--r-- | src/test/DoS_tests.cpp | 45 |
4 files changed, 0 insertions, 97 deletions
diff --git a/src/main.cpp b/src/main.cpp index 604ca670ef..dba4292f50 100644 --- a/src/main.cpp +++ b/src/main.cpp @@ -2329,23 +2329,6 @@ bool AcceptBlockHeader(const CBlockHeader& block, CValidationState& state, CBloc return true; } - CBlockIndex* pcheckpoint = Checkpoints::GetLastCheckpoint(); - if (pcheckpoint && block.hashPrevBlock != (chainActive.Tip() ? chainActive.Tip()->GetBlockHash() : uint256(0))) - { - // Extra checks to prevent "fill up memory by spamming with bogus blocks" - int64_t deltaTime = block.GetBlockTime() - pcheckpoint->GetBlockTime(); - if (deltaTime < 0) - { - return state.DoS(100, error("%s : block with timestamp before last checkpoint", __func__), - REJECT_CHECKPOINT, "time-too-old"); - } - if (!CheckMinWork(block.nBits, pcheckpoint->nBits, deltaTime)) - { - return state.DoS(100, error("%s : block with too little proof-of-work", __func__), - REJECT_INVALID, "bad-diffbits"); - } - } - // Get prev block index CBlockIndex* pindexPrev = NULL; int nHeight = 0; diff --git a/src/pow.cpp b/src/pow.cpp index d50222849c..75fbfc6a6d 100644 --- a/src/pow.cpp +++ b/src/pow.cpp @@ -98,39 +98,6 @@ bool CheckProofOfWork(uint256 hash, unsigned int nBits) return true; } -// -// true if nBits is greater than the minimum amount of work that could -// possibly be required deltaTime after minimum work required was nBase -// -bool CheckMinWork(unsigned int nBits, unsigned int nBase, int64_t deltaTime) -{ - bool fOverflow = false; - uint256 bnNewBlock; - bnNewBlock.SetCompact(nBits, NULL, &fOverflow); - if (fOverflow) - return false; - - const uint256 &bnLimit = Params().ProofOfWorkLimit(); - // Testnet has min-difficulty blocks - // after Params().TargetSpacing()*2 time between blocks: - if (Params().AllowMinDifficultyBlocks() && deltaTime > Params().TargetSpacing()*2) - return bnNewBlock <= bnLimit; - - uint256 bnResult; - bnResult.SetCompact(nBase); - while (deltaTime > 0 && bnResult < bnLimit) - { - // Maximum 400% adjustment... - bnResult *= 4; - // ... in best-case exactly 4-times-normal target time - deltaTime -= Params().TargetTimespan()*4; - } - if (bnResult > bnLimit) - bnResult = bnLimit; - - return bnNewBlock <= bnResult; -} - void UpdateTime(CBlockHeader* pblock, const CBlockIndex* pindexPrev) { pblock->nTime = std::max(pindexPrev->GetMedianTimePast()+1, GetAdjustedTime()); @@ -16,8 +16,6 @@ unsigned int GetNextWorkRequired(const CBlockIndex* pindexLast, const CBlockHead /** Check whether a block hash satisfies the proof-of-work requirement specified by nBits */ bool CheckProofOfWork(uint256 hash, unsigned int nBits); -/** Check the work is more than the minimum a received block needs, without knowing its direct parent */ -bool CheckMinWork(unsigned int nBits, unsigned int nBase, int64_t deltaTime); void UpdateTime(CBlockHeader* block, const CBlockIndex* pindexPrev); diff --git a/src/test/DoS_tests.cpp b/src/test/DoS_tests.cpp index 7bec12b665..f9746fdaa5 100644 --- a/src/test/DoS_tests.cpp +++ b/src/test/DoS_tests.cpp @@ -106,51 +106,6 @@ BOOST_AUTO_TEST_CASE(DoS_bantime) BOOST_CHECK(!CNode::IsBanned(addr)); } -static bool CheckNBits(unsigned int nbits1, int64_t time1, unsigned int nbits2, int64_t time2)\ -{ - if (time1 > time2) - return CheckNBits(nbits2, time2, nbits1, time1); - int64_t deltaTime = time2-time1; - - return CheckMinWork(nbits2, nbits1, deltaTime); -} - -BOOST_AUTO_TEST_CASE(DoS_checknbits) -{ - using namespace boost::assign; // for 'map_list_of()' - - // Timestamps,nBits from the bitcoin block chain. - // These are the block-chain checkpoint blocks - typedef std::map<int64_t, unsigned int> BlockData; - BlockData chainData = - map_list_of(1239852051,486604799)(1262749024,486594666) - (1279305360,469854461)(1280200847,469830746)(1281678674,469809688) - (1296207707,453179945)(1302624061,453036989)(1309640330,437004818) - (1313172719,436789733); - - // Make sure CheckNBits considers every combination of block-chain-lock-in-points - // "sane": - BOOST_FOREACH(const BlockData::value_type& i, chainData) - { - BOOST_FOREACH(const BlockData::value_type& j, chainData) - { - BOOST_CHECK(CheckNBits(i.second, i.first, j.second, j.first)); - } - } - - // Test a couple of insane combinations: - BlockData::value_type firstcheck = *(chainData.begin()); - BlockData::value_type lastcheck = *(chainData.rbegin()); - - // First checkpoint difficulty at or a while after the last checkpoint time should fail when - // compared to last checkpoint - BOOST_CHECK(!CheckNBits(firstcheck.second, lastcheck.first+60*10, lastcheck.second, lastcheck.first)); - BOOST_CHECK(!CheckNBits(firstcheck.second, lastcheck.first+60*60*24*14, lastcheck.second, lastcheck.first)); - - // ... but OK if enough time passed for difficulty to adjust downward: - BOOST_CHECK(CheckNBits(firstcheck.second, lastcheck.first+60*60*24*365*4, lastcheck.second, lastcheck.first)); -} - CTransaction RandomOrphan() { std::map<uint256, COrphanTx>::iterator it; |