From b475d7d0fa000d5802caf3065b8b2abcea60719b Mon Sep 17 00:00:00 2001 From: Jeremy Rubin Date: Mon, 7 Oct 2019 13:45:00 -0700 Subject: [PATCH 1/3] Add single sha256 call to CHashWriter --- src/hash.h | 27 ++++++++++++++++++++------- 1 file changed, 20 insertions(+), 7 deletions(-) diff --git a/src/hash.h b/src/hash.h index 71806483ff1..4f392fa0aa3 100644 --- a/src/hash.h +++ b/src/hash.h @@ -98,7 +98,7 @@ inline uint160 Hash160(const T1& in1) class CHashWriter { private: - CHash256 ctx; + CSHA256 ctx; const int nType; const int nVersion; @@ -110,13 +110,27 @@ public: int GetVersion() const { return nVersion; } void write(const char *pch, size_t size) { - ctx.Write({(const unsigned char*)pch, size}); + ctx.Write((const unsigned char*)pch, size); } - // invalidates the object + /** Compute the double-SHA256 hash of all data written to this object. + * + * Invalidates this object. + */ uint256 GetHash() { uint256 result; - ctx.Finalize(result); + ctx.Finalize(result.begin()); + ctx.Reset().Write(result.begin(), CSHA256::OUTPUT_SIZE).Finalize(result.begin()); + return result; + } + + /** Compute the SHA256 hash of all data written to this object. + * + * Invalidates this object. + */ + uint256 GetSHA256() { + uint256 result; + ctx.Finalize(result.begin()); return result; } @@ -124,9 +138,8 @@ public: * Returns the first 64 bits from the resulting hash. */ inline uint64_t GetCheapHash() { - unsigned char result[CHash256::OUTPUT_SIZE]; - ctx.Finalize(result); - return ReadLE64(result); + uint256 result = GetHash(); + return ReadLE64(result.begin()); } template From 6510d0ff4173a7b01d6728051303c7c38eb34533 Mon Sep 17 00:00:00 2001 From: Jeremy Rubin Date: Wed, 5 Feb 2020 11:57:32 -0800 Subject: [PATCH 2/3] Add SHA256Uint256 helper functions --- src/hash.cpp | 7 +++++++ src/hash.h | 4 ++++ 2 files changed, 11 insertions(+) diff --git a/src/hash.cpp b/src/hash.cpp index 4c09f5f6463..83b90ae063f 100644 --- a/src/hash.cpp +++ b/src/hash.cpp @@ -77,3 +77,10 @@ void BIP32Hash(const ChainCode &chainCode, unsigned int nChild, unsigned char he num[3] = (nChild >> 0) & 0xFF; CHMAC_SHA512(chainCode.begin(), chainCode.size()).Write(&header, 1).Write(data, 32).Write(num, 4).Finalize(output); } + +uint256 SHA256Uint256(const uint256& input) +{ + uint256 result; + CSHA256().Write(input.begin(), 32).Finalize(result.begin()); + return result; +} diff --git a/src/hash.h b/src/hash.h index 4f392fa0aa3..c16bbb48cea 100644 --- a/src/hash.h +++ b/src/hash.h @@ -6,6 +6,7 @@ #ifndef BITCOIN_HASH_H #define BITCOIN_HASH_H +#include #include #include #include @@ -194,6 +195,9 @@ uint256 SerializeHash(const T& obj, int nType=SER_GETHASH, int nVersion=PROTOCOL return ss.GetHash(); } +/** Single-SHA256 a 32-byte input (represented as uint256). */ +NODISCARD uint256 SHA256Uint256(const uint256& input); + unsigned int MurmurHash3(unsigned int nHashSeed, Span vDataToHash); void BIP32Hash(const ChainCode &chainCode, unsigned int nChild, unsigned char header, const unsigned char data[32], unsigned char output[64]); From 9ab4cafabda227ccee5b241d7690fc67f9a27221 Mon Sep 17 00:00:00 2001 From: Jeremy Rubin Date: Wed, 5 Feb 2020 12:31:20 -0800 Subject: [PATCH 3/3] Refactor Get{Prevout,Sequence,Outputs}Hash to Get{Prevouts,Sequences,Outputs}SHA256. Several proposals (Taproot, MuHash, CTV) require access to the single hash. --- src/script/interpreter.cpp | 27 +++++++++++++++------------ 1 file changed, 15 insertions(+), 12 deletions(-) diff --git a/src/script/interpreter.cpp b/src/script/interpreter.cpp index 39feb4ccc92..7b2457a5e39 100644 --- a/src/script/interpreter.cpp +++ b/src/script/interpreter.cpp @@ -1258,34 +1258,37 @@ public: } }; +/** Compute the (single) SHA256 of the concatenation of all prevouts of a tx. */ template -uint256 GetPrevoutHash(const T& txTo) +uint256 GetPrevoutsSHA256(const T& txTo) { CHashWriter ss(SER_GETHASH, 0); for (const auto& txin : txTo.vin) { ss << txin.prevout; } - return ss.GetHash(); + return ss.GetSHA256(); } +/** Compute the (single) SHA256 of the concatenation of all nSequences of a tx. */ template -uint256 GetSequenceHash(const T& txTo) +uint256 GetSequencesSHA256(const T& txTo) { CHashWriter ss(SER_GETHASH, 0); for (const auto& txin : txTo.vin) { ss << txin.nSequence; } - return ss.GetHash(); + return ss.GetSHA256(); } +/** Compute the (single) SHA256 of the concatenation of all txouts of a tx. */ template -uint256 GetOutputsHash(const T& txTo) +uint256 GetOutputsSHA256(const T& txTo) { CHashWriter ss(SER_GETHASH, 0); for (const auto& txout : txTo.vout) { ss << txout; } - return ss.GetHash(); + return ss.GetSHA256(); } } // namespace @@ -1297,9 +1300,9 @@ void PrecomputedTransactionData::Init(const T& txTo) // Cache is calculated only for transactions with witness if (txTo.HasWitness()) { - hashPrevouts = GetPrevoutHash(txTo); - hashSequence = GetSequenceHash(txTo); - hashOutputs = GetOutputsHash(txTo); + hashPrevouts = SHA256Uint256(GetPrevoutsSHA256(txTo)); + hashSequence = SHA256Uint256(GetSequencesSHA256(txTo)); + hashOutputs = SHA256Uint256(GetOutputsSHA256(txTo)); } m_ready = true; @@ -1329,16 +1332,16 @@ uint256 SignatureHash(const CScript& scriptCode, const T& txTo, unsigned int nIn const bool cacheready = cache && cache->m_ready; if (!(nHashType & SIGHASH_ANYONECANPAY)) { - hashPrevouts = cacheready ? cache->hashPrevouts : GetPrevoutHash(txTo); + hashPrevouts = cacheready ? cache->hashPrevouts : SHA256Uint256(GetPrevoutsSHA256(txTo)); } if (!(nHashType & SIGHASH_ANYONECANPAY) && (nHashType & 0x1f) != SIGHASH_SINGLE && (nHashType & 0x1f) != SIGHASH_NONE) { - hashSequence = cacheready ? cache->hashSequence : GetSequenceHash(txTo); + hashSequence = cacheready ? cache->hashSequence : SHA256Uint256(GetSequencesSHA256(txTo)); } if ((nHashType & 0x1f) != SIGHASH_SINGLE && (nHashType & 0x1f) != SIGHASH_NONE) { - hashOutputs = cacheready ? cache->hashOutputs : GetOutputsHash(txTo); + hashOutputs = cacheready ? cache->hashOutputs : SHA256Uint256(GetOutputsSHA256(txTo)); } else if ((nHashType & 0x1f) == SIGHASH_SINGLE && nIn < txTo.vout.size()) { CHashWriter ss(SER_GETHASH, 0); ss << txTo.vout[nIn];