From 69fc8047a9a96bcf5360f810c796049c27e16fcd Mon Sep 17 00:00:00 2001 From: Pieter Wuille Date: Fri, 15 Jun 2012 18:52:19 +0200 Subject: Compact serialization for scripts Special serializers for script which detect common cases and encode them much more efficiently. 3 special cases are defined: * Pay to pubkey hash (encoded as 21 bytes) * Pay to script hash (encoded as 21 bytes) * Pay to pubkey starting with 0x02, 0x03 or 0x04 (encoded as 33 bytes) Other scripts up to 121 bytes require 1 byte + script length. Above that, scripts up to 16505 bytes require 2 bytes + script length. --- src/script.cpp | 125 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 125 insertions(+) (limited to 'src/script.cpp') diff --git a/src/script.cpp b/src/script.cpp index 89bc5632b..a840bb1c0 100644 --- a/src/script.cpp +++ b/src/script.cpp @@ -1951,3 +1951,128 @@ void CScript::SetMultisig(int nRequired, const std::vector& keys) *this << key.GetPubKey(); *this << EncodeOP_N(keys.size()) << OP_CHECKMULTISIG; } + +bool CScriptCompressor::IsToKeyID(CKeyID &hash) const +{ + if (script.size() == 25 && script[0] == OP_DUP && script[1] == OP_HASH160 + && script[2] == 20 && script[23] == OP_EQUALVERIFY + && script[24] == OP_CHECKSIG) { + memcpy(&hash, &script[3], 20); + return true; + } + return false; +} + +bool CScriptCompressor::IsToScriptID(CScriptID &hash) const +{ + if (script.size() == 23 && script[0] == OP_HASH160 && script[1] == 20 + && script[22] == OP_EQUAL) { + memcpy(&hash, &script[2], 20); + return true; + } + return false; +} + +bool CScriptCompressor::IsToPubKey(std::vector &pubkey) const +{ + if (script.size() == 35 && script[0] == 33 && script[34] == OP_CHECKSIG + && (script[1] == 0x02 || script[1] == 0x03)) { + pubkey.resize(33); + memcpy(&pubkey[0], &script[1], 33); + return true; + } + if (script.size() == 67 && script[0] == 65 && script[66] == OP_CHECKSIG + && script[1] == 0x04) { + pubkey.resize(65); + memcpy(&pubkey[0], &script[1], 65); + CKey key; + return (key.SetPubKey(CPubKey(pubkey))); // SetPubKey fails if this is not a valid public key, a case that would not be compressible + } + return false; +} + +bool CScriptCompressor::Compress(std::vector &out) const +{ + CKeyID keyID; + if (IsToKeyID(keyID)) { + out.resize(21); + out[0] = 0x00; + memcpy(&out[1], &keyID, 20); + return true; + } + CScriptID scriptID; + if (IsToScriptID(scriptID)) { + out.resize(21); + out[0] = 0x01; + memcpy(&out[1], &scriptID, 20); + return true; + } + std::vector pubkey; + if (IsToPubKey(pubkey)) { + out.resize(33); + memcpy(&out[1], &pubkey[1], 32); + if (pubkey[0] == 0x02 || pubkey[0] == 0x03) { + out[0] = pubkey[0]; + return true; + } else if (pubkey[0] == 0x04) { + out[0] = 0x04 | (pubkey[64] & 0x01); + return true; + } + } + return false; +} + +unsigned int CScriptCompressor::GetSpecialSize(unsigned int nSize) const +{ + if (nSize == 0 || nSize == 1) + return 20; + if (nSize == 2 || nSize == 3 || nSize == 4 || nSize == 5) + return 32; + return 0; +} + +bool CScriptCompressor::Decompress(unsigned int nSize, const std::vector &in) +{ + switch(nSize) { + case 0x00: + script.resize(25); + script[0] = OP_DUP; + script[1] = OP_HASH160; + script[2] = 20; + memcpy(&script[3], &in[0], 20); + script[23] = OP_EQUALVERIFY; + script[24] = OP_CHECKSIG; + return true; + case 0x01: + script.resize(23); + script[0] = OP_HASH160; + script[1] = 20; + memcpy(&script[2], &in[0], 20); + script[22] = OP_EQUAL; + return true; + case 0x02: + case 0x03: + script.resize(35); + script[0] = 33; + script[1] = nSize; + memcpy(&script[2], &in[0], 32); + script[34] = OP_CHECKSIG; + return true; + case 0x04: + case 0x05: + std::vector vch(33, 0x00); + vch[0] = nSize - 2; + memcpy(&vch[1], &in[0], 32); + CKey key; + if (!key.SetPubKey(CPubKey(vch))) + return false; + key.SetCompressedPubKey(false); // Decompress public key + CPubKey pubkey = key.GetPubKey(); + script.resize(67); + script[0] = 65; + memcpy(&script[1], &pubkey.Raw()[0], 65); + script[66] = OP_CHECKSIG; + return true; + } + return false; +} -- cgit v1.2.3 From 450cbb0944cd20a06ce806e6679a1f4c83c50db2 Mon Sep 17 00:00:00 2001 From: Pieter Wuille Date: Sun, 1 Jul 2012 18:54:00 +0200 Subject: Ultraprune This switches bitcoin's transaction/block verification logic to use a "coin database", which contains all unredeemed transaction output scripts, amounts and heights. The name ultraprune comes from the fact that instead of a full transaction index, we only (need to) keep an index with unspent outputs. For now, the blocks themselves are kept as usual, although they are only necessary for serving, rescanning and reorganizing. The basic datastructures are CCoins (representing the coins of a single transaction), and CCoinsView (representing a state of the coins database). There are several implementations for CCoinsView. A dummy, one backed by the coins database (coins.dat), one backed by the memory pool, and one that adds a cache on top of it. FetchInputs, ConnectInputs, ConnectBlock, DisconnectBlock, ... now operate on a generic CCoinsView. The block switching logic now builds a single cached CCoinsView with changes to be committed to the database before any changes are made. This means no uncommitted changes are ever read from the database, and should ease the transition to another database layer which does not support transactions (but does support atomic writes), like LevelDB. For the getrawtransaction() RPC call, access to a txid-to-disk index would be preferable. As this index is not necessary or even useful for any other part of the implementation, it is not provided. Instead, getrawtransaction() uses the coin database to find the block height, and then scans that block to find the requested transaction. This is slow, but should suffice for debug purposes. --- src/script.cpp | 5 +---- 1 file changed, 1 insertion(+), 4 deletions(-) (limited to 'src/script.cpp') diff --git a/src/script.cpp b/src/script.cpp index a840bb1c0..61112b17c 100644 --- a/src/script.cpp +++ b/src/script.cpp @@ -1719,7 +1719,7 @@ bool SignSignature(const CKeyStore &keystore, const CTransaction& txFrom, CTrans return SignSignature(keystore, txout.scriptPubKey, txTo, nIn, nHashType); } -bool VerifySignature(const CTransaction& txFrom, const CTransaction& txTo, unsigned int nIn, bool fValidatePayToScriptHash, bool fStrictEncodings, int nHashType) +bool VerifySignature(const CCoins& txFrom, const CTransaction& txTo, unsigned int nIn, bool fValidatePayToScriptHash, bool fStrictEncodings, int nHashType) { assert(nIn < txTo.vin.size()); const CTxIn& txin = txTo.vin[nIn]; @@ -1727,9 +1727,6 @@ bool VerifySignature(const CTransaction& txFrom, const CTransaction& txTo, unsig return false; const CTxOut& txout = txFrom.vout[txin.prevout.n]; - if (txin.prevout.hash != txFrom.GetHash()) - return false; - return VerifyScript(txin.scriptSig, txout.scriptPubKey, txTo, nIn, fValidatePayToScriptHash, fStrictEncodings, nHashType); } -- cgit v1.2.3