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author | chriseth <c@ethdev.com> | 2016-11-15 04:35:24 +0800 |
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committer | chriseth <c@ethdev.com> | 2016-11-15 06:14:10 +0800 |
commit | 8944b092f8de074ec2c98434cb4c76d804146bd6 (patch) | |
tree | 8b0fb073bbecbfee1ace5e8169cd28daeb367da8 /libdevcore | |
parent | 2f83a4557729753d6da28eddd28d54bfc18bf5e1 (diff) | |
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Multi-level swarm hash.
Diffstat (limited to 'libdevcore')
-rw-r--r-- | libdevcore/SHA3.cpp | 43 | ||||
-rw-r--r-- | libdevcore/SHA3.h | 9 |
2 files changed, 44 insertions, 8 deletions
diff --git a/libdevcore/SHA3.cpp b/libdevcore/SHA3.cpp index 3b12f39f..96c7b764 100644 --- a/libdevcore/SHA3.cpp +++ b/libdevcore/SHA3.cpp @@ -238,4 +238,47 @@ bool keccak256(bytesConstRef _input, bytesRef o_output) return true; } +bytes toLittleEndian(size_t _size) +{ + bytes encoded(8); + for (size_t i = 0; i < 8; ++i) + encoded[i] = (_size >> (8 * i)) & 0xff; + return encoded; +} + +h256 swarmHashSimple(bytesConstRef _data, size_t _size) +{ + return keccak256(toLittleEndian(_size) + _data.toBytes()); +} + +h256 swarmHash(bytes const& _input) +{ + bytes data = _input; + size_t lastChunkSize = 0; + size_t level = 0; + do + { + bytes innerNodes; + size_t i = 0; + do + { + size_t bytes = std::min<size_t>(0x1000, data.size() - i); + size_t size = bytes << (7 * level); + if (i + 0x1000 >= data.size()) + { + // last node + size = level == 0 ? bytes : ((bytes - 32) << (7 * level)) + lastChunkSize; + lastChunkSize = size; + } + innerNodes += swarmHashSimple(bytesConstRef(_input.data() + i, bytes), size).asBytes(); + i += 0x1000; + } + while (i < data.size()); + data = std::move(innerNodes); + level++; + } + while (data.size() > 32); + return h256(data); +} + } diff --git a/libdevcore/SHA3.h b/libdevcore/SHA3.h index e3ff1335..ea0c761d 100644 --- a/libdevcore/SHA3.h +++ b/libdevcore/SHA3.h @@ -53,12 +53,5 @@ inline std::string keccak256(std::string const& _input, bool _isNibbles) { retur /// Calculate SHA3-256 MAC inline void keccak256mac(bytesConstRef _secret, bytesConstRef _plain, bytesRef _output) { keccak256(_secret.toBytes() + _plain.toBytes()).ref().populate(_output); } -h256 swarmHash(bytes const& _data) -{ - bytes size(8); - for (size_t i = 0; i < 8; ++i) - size[i] = (_data.size() >> (8 * i)) & 0xff; - - return keccak256(size + _data); -} +h256 swarmHash(bytes const& _data); } |