bc8cca4896
Changes are as below: Wrap CBlockHeader::nVersion into a new class (CBlockVersion). This allows to take care of interpreting the field into a base version, auxpow flag and the chain ID. Update getauxblock.py for new 'generate' RPC call. Add 'auxpow' to block JSON. Accept auxpow as PoW verification. Add unit tests for auxpow verification. Add check for memory-layout of CBlockVersion. Weaken auxpow chain ID checks for the testnet. Allow Params() to overrule when to check the auxpow chain ID and for legacy blocks. Use this to disable the checks on testnet. Introduce CPureBlockHeader. Split the block header part that is used by auxpow and the "real" block header (that uses auxpow) to resolve the cyclic dependency between the two. Differentiate between uint256 and arith_uint256. This change was done upstream, modify the auxpow code. Add missing lock in auxpow_tests. Fix REST header check for auxpow headers. Those can be longer, thus take that into account. Also perform the check actually on an auxpow header. Correctly set the coinbase for getauxblock results. Call IncrementExtraNonce in getauxblock so that the coinbase is actually initialised with the stuff it should be. (BIP30 block height and COINBASE_FLAGS.) Implement getauxblock plus regression test. Turn auxpow test into FIXTURE test. This allows using of the Params() calls. Move CMerkleTx code to auxpow.cpp. Otherwise we get linker errors when building without wallet. Fix rebase with BIP66. Update the code to handle BIP66's nVersion=3. Enforce that auxpow parent blocks have no auxpow block version. This is for compatibility with namecoind. See also https://github.com/namecoin/namecoin/pull/199. Move auxpow-related parameters to Consensus::Params.
104 lines
3.7 KiB
C++
104 lines
3.7 KiB
C++
// Copyright (c) 2009-2010 Satoshi Nakamoto
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// Copyright (c) 2009-2016 The Bitcoin Core developers
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// Distributed under the MIT software license, see the accompanying
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// file COPYING or http://www.opensource.org/licenses/mit-license.php.
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#include "pow.h"
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#include "auxpow.h"
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#include "arith_uint256.h"
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#include "chain.h"
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#include "dogecoin.h"
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#include "primitives/block.h"
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#include "uint256.h"
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#include "util.h"
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unsigned int GetNextWorkRequired(const CBlockIndex* pindexLast, const CBlockHeader *pblock, const Consensus::Params& params)
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{
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unsigned int nProofOfWorkLimit = UintToArith256(params.powLimit).GetCompact();
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// Genesis block
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if (pindexLast == NULL)
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return nProofOfWorkLimit;
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// Only change once per difficulty adjustment interval
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if ((pindexLast->nHeight+1) % params.DifficultyAdjustmentInterval() != 0)
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{
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if (params.fPowAllowMinDifficultyBlocks)
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{
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// Special difficulty rule for testnet:
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// If the new block's timestamp is more than 2* 10 minutes
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// then allow mining of a min-difficulty block.
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if (pblock->GetBlockTime() > pindexLast->GetBlockTime() + params.nPowTargetSpacing*2)
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return nProofOfWorkLimit;
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else
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{
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// Return the last non-special-min-difficulty-rules-block
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const CBlockIndex* pindex = pindexLast;
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while (pindex->pprev && pindex->nHeight % params.DifficultyAdjustmentInterval() != 0 && pindex->nBits == nProofOfWorkLimit)
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pindex = pindex->pprev;
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return pindex->nBits;
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}
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}
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return pindexLast->nBits;
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}
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// Litecoin: This fixes an issue where a 51% attack can change difficulty at will.
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// Go back the full period unless it's the first retarget after genesis. Code courtesy of Art Forz
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int blockstogoback = params.DifficultyAdjustmentInterval()-1;
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if ((pindexLast->nHeight+1) != params.DifficultyAdjustmentInterval())
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blockstogoback = params.DifficultyAdjustmentInterval();
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// Go back by what we want to be 14 days worth of blocks
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int nHeightFirst = pindexLast->nHeight - blockstogoback;
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assert(nHeightFirst >= 0);
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const CBlockIndex* pindexFirst = pindexLast->GetAncestor(nHeightFirst);
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assert(pindexFirst);
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return CalculateDogecoinNextWorkRequired(pindexLast, pindexFirst->GetBlockTime(), params);
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}
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unsigned int CalculateNextWorkRequired(const CBlockIndex* pindexLast, int64_t nFirstBlockTime, const Consensus::Params& params)
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{
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if (params.fPowNoRetargeting)
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return pindexLast->nBits;
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// Limit adjustment step
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int64_t nActualTimespan = pindexLast->GetBlockTime() - nFirstBlockTime;
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if (nActualTimespan < params.nPowTargetTimespan/4)
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nActualTimespan = params.nPowTargetTimespan/4;
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if (nActualTimespan > params.nPowTargetTimespan*4)
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nActualTimespan = params.nPowTargetTimespan*4;
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// Retarget
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const arith_uint256 bnPowLimit = UintToArith256(params.powLimit);
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arith_uint256 bnNew;
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bnNew.SetCompact(pindexLast->nBits);
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bnNew *= nActualTimespan;
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bnNew /= params.nPowTargetTimespan;
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if (bnNew > bnPowLimit)
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bnNew = bnPowLimit;
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return bnNew.GetCompact();
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}
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bool CheckProofOfWork(uint256 hash, unsigned int nBits, const Consensus::Params& params)
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{
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bool fNegative;
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bool fOverflow;
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arith_uint256 bnTarget;
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bnTarget.SetCompact(nBits, &fNegative, &fOverflow);
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// Check range
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if (fNegative || bnTarget == 0 || fOverflow || bnTarget > UintToArith256(params.powLimit))
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return false;
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// Check proof of work matches claimed amount
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if (UintToArith256(hash) > bnTarget)
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return false;
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return true;
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}
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