mirror of
https://github.com/ethereum/solidity
synced 2023-10-03 13:03:40 +00:00
117 lines
3.0 KiB
C++
117 lines
3.0 KiB
C++
/*
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This file is part of solidity.
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solidity is free software: you can redistribute it and/or modify
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it under the terms of the GNU General Public License as published by
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the Free Software Foundation, either version 3 of the License, or
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(at your option) any later version.
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solidity is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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GNU General Public License for more details.
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You should have received a copy of the GNU General Public License
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along with solidity. If not, see <http://www.gnu.org/licenses/>.
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*/
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/** @file SwarmHash.cpp
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*/
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#include <libdevcore/SwarmHash.h>
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#include <libdevcore/Keccak256.h>
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using namespace std;
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using namespace dev;
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namespace
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{
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bytes toLittleEndian(size_t _size)
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{
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bytes encoded(8);
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for (size_t i = 0; i < 8; ++i)
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encoded[i] = (_size >> (8 * i)) & 0xff;
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return encoded;
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}
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h256 swarmHashSimple(bytesConstRef _data, size_t _size)
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{
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return keccak256(toLittleEndian(_size) + _data.toBytes());
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}
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h256 swarmHashIntermediate(string const& _input, size_t _offset, size_t _length)
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{
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bytesConstRef ref;
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bytes innerNodes;
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if (_length <= 0x1000)
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ref = bytesConstRef(_input).cropped(_offset, _length);
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else
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{
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size_t maxRepresentedSize = 0x1000;
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while (maxRepresentedSize * (0x1000 / 32) < _length)
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maxRepresentedSize *= (0x1000 / 32);
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for (size_t i = 0; i < _length; i += maxRepresentedSize)
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{
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size_t size = std::min(maxRepresentedSize, _length - i);
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innerNodes += swarmHashIntermediate(_input, _offset + i, size).asBytes();
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}
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ref = bytesConstRef(&innerNodes);
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}
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return swarmHashSimple(ref, _length);
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}
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h256 bmtHash(bytesConstRef _data)
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{
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if (_data.size() <= 64)
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return keccak256(_data);
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size_t midPoint = _data.size() / 2;
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return keccak256(
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bmtHash(_data.cropped(0, midPoint)).asBytes() +
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bmtHash(_data.cropped(midPoint)).asBytes()
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);
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}
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h256 chunkHash(bytesConstRef const _data, bool _forceHigherLevel = false)
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{
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bytes dataToHash;
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if (_data.size() < 0x1000)
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dataToHash = _data.toBytes();
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else if (_data.size() == 0x1000 && !_forceHigherLevel)
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dataToHash = _data.toBytes();
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else
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{
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size_t maxRepresentedSize = 0x1000;
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while (maxRepresentedSize * (0x1000 / 32) < _data.size())
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maxRepresentedSize *= (0x1000 / 32);
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// If remaining size is 0x1000, but maxRepresentedSize is not,
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// we have to still do one level of the chunk hashes.
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bool forceHigher = maxRepresentedSize > 0x1000;
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for (size_t i = 0; i < _data.size(); i += maxRepresentedSize)
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{
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size_t size = std::min(maxRepresentedSize, _data.size() - i);
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dataToHash += chunkHash(_data.cropped(i, size), forceHigher).asBytes();
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}
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}
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dataToHash.resize(0x1000, 0);
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return keccak256(toLittleEndian(_data.size()) + bmtHash(&dataToHash).asBytes());
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}
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}
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h256 dev::bzzr0Hash(string const& _input)
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{
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return swarmHashIntermediate(_input, 0, _input.size());
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}
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h256 dev::bzzr1Hash(bytes const& _input)
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{
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if (_input.empty())
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return h256{};
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return chunkHash(&_input);
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}
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