diff options
Diffstat (limited to 'src/script')
| -rw-r--r-- | src/script/standard.cpp | 254 | ||||
| -rw-r--r-- | src/script/standard.h | 56 |
2 files changed, 310 insertions, 0 deletions
diff --git a/src/script/standard.cpp b/src/script/standard.cpp new file mode 100644 index 0000000000..684edff4d2 --- /dev/null +++ b/src/script/standard.cpp @@ -0,0 +1,254 @@ +// Copyright (c) 2009-2010 Satoshi Nakamoto +// Copyright (c) 2009-2013 The Bitcoin developers +// Distributed under the MIT/X11 software license, see the accompanying +// file COPYING or http://www.opensource.org/licenses/mit-license.php. + +#include "script/standard.h" + +#include "script/script.h" +#include "util.h" + +#include <boost/foreach.hpp> + +using namespace std; + +typedef vector<unsigned char> valtype; + +const char* GetTxnOutputType(txnouttype t) +{ + switch (t) + { + case TX_NONSTANDARD: return "nonstandard"; + case TX_PUBKEY: return "pubkey"; + case TX_PUBKEYHASH: return "pubkeyhash"; + case TX_SCRIPTHASH: return "scripthash"; + case TX_MULTISIG: return "multisig"; + case TX_NULL_DATA: return "nulldata"; + } + return NULL; +} + +// +// Return public keys or hashes from scriptPubKey, for 'standard' transaction types. +// +bool Solver(const CScript& scriptPubKey, txnouttype& typeRet, vector<vector<unsigned char> >& vSolutionsRet) +{ + // Templates + static multimap<txnouttype, CScript> mTemplates; + if (mTemplates.empty()) + { + // Standard tx, sender provides pubkey, receiver adds signature + mTemplates.insert(make_pair(TX_PUBKEY, CScript() << OP_PUBKEY << OP_CHECKSIG)); + + // Bitcoin address tx, sender provides hash of pubkey, receiver provides signature and pubkey + mTemplates.insert(make_pair(TX_PUBKEYHASH, CScript() << OP_DUP << OP_HASH160 << OP_PUBKEYHASH << OP_EQUALVERIFY << OP_CHECKSIG)); + + // Sender provides N pubkeys, receivers provides M signatures + mTemplates.insert(make_pair(TX_MULTISIG, CScript() << OP_SMALLINTEGER << OP_PUBKEYS << OP_SMALLINTEGER << OP_CHECKMULTISIG)); + + // Empty, provably prunable, data-carrying output + if (GetBoolArg("-datacarrier", true)) + mTemplates.insert(make_pair(TX_NULL_DATA, CScript() << OP_RETURN << OP_SMALLDATA)); + mTemplates.insert(make_pair(TX_NULL_DATA, CScript() << OP_RETURN)); + } + + // Shortcut for pay-to-script-hash, which are more constrained than the other types: + // it is always OP_HASH160 20 [20 byte hash] OP_EQUAL + if (scriptPubKey.IsPayToScriptHash()) + { + typeRet = TX_SCRIPTHASH; + vector<unsigned char> hashBytes(scriptPubKey.begin()+2, scriptPubKey.begin()+22); + vSolutionsRet.push_back(hashBytes); + return true; + } + + // Scan templates + const CScript& script1 = scriptPubKey; + BOOST_FOREACH(const PAIRTYPE(txnouttype, CScript)& tplate, mTemplates) + { + const CScript& script2 = tplate.second; + vSolutionsRet.clear(); + + opcodetype opcode1, opcode2; + vector<unsigned char> vch1, vch2; + + // Compare + CScript::const_iterator pc1 = script1.begin(); + CScript::const_iterator pc2 = script2.begin(); + while (true) + { + if (pc1 == script1.end() && pc2 == script2.end()) + { + // Found a match + typeRet = tplate.first; + if (typeRet == TX_MULTISIG) + { + // Additional checks for TX_MULTISIG: + unsigned char m = vSolutionsRet.front()[0]; + unsigned char n = vSolutionsRet.back()[0]; + if (m < 1 || n < 1 || m > n || vSolutionsRet.size()-2 != n) + return false; + } + return true; + } + if (!script1.GetOp(pc1, opcode1, vch1)) + break; + if (!script2.GetOp(pc2, opcode2, vch2)) + break; + + // Template matching opcodes: + if (opcode2 == OP_PUBKEYS) + { + while (vch1.size() >= 33 && vch1.size() <= 65) + { + vSolutionsRet.push_back(vch1); + if (!script1.GetOp(pc1, opcode1, vch1)) + break; + } + if (!script2.GetOp(pc2, opcode2, vch2)) + break; + // Normal situation is to fall through + // to other if/else statements + } + + if (opcode2 == OP_PUBKEY) + { + if (vch1.size() < 33 || vch1.size() > 65) + break; + vSolutionsRet.push_back(vch1); + } + else if (opcode2 == OP_PUBKEYHASH) + { + if (vch1.size() != sizeof(uint160)) + break; + vSolutionsRet.push_back(vch1); + } + else if (opcode2 == OP_SMALLINTEGER) + { // Single-byte small integer pushed onto vSolutions + if (opcode1 == OP_0 || + (opcode1 >= OP_1 && opcode1 <= OP_16)) + { + char n = (char)CScript::DecodeOP_N(opcode1); + vSolutionsRet.push_back(valtype(1, n)); + } + else + break; + } + else if (opcode2 == OP_SMALLDATA) + { + // small pushdata, <= MAX_OP_RETURN_RELAY bytes + if (vch1.size() > MAX_OP_RETURN_RELAY) + break; + } + else if (opcode1 != opcode2 || vch1 != vch2) + { + // Others must match exactly + break; + } + } + } + + vSolutionsRet.clear(); + typeRet = TX_NONSTANDARD; + return false; +} + +int ScriptSigArgsExpected(txnouttype t, const std::vector<std::vector<unsigned char> >& vSolutions) +{ + switch (t) + { + case TX_NONSTANDARD: + case TX_NULL_DATA: + return -1; + case TX_PUBKEY: + return 1; + case TX_PUBKEYHASH: + return 2; + case TX_MULTISIG: + if (vSolutions.size() < 1 || vSolutions[0].size() < 1) + return -1; + return vSolutions[0][0] + 1; + case TX_SCRIPTHASH: + return 1; // doesn't include args needed by the script + } + return -1; +} + +bool IsStandard(const CScript& scriptPubKey, txnouttype& whichType) +{ + vector<valtype> vSolutions; + if (!Solver(scriptPubKey, whichType, vSolutions)) + return false; + + if (whichType == TX_MULTISIG) + { + unsigned char m = vSolutions.front()[0]; + unsigned char n = vSolutions.back()[0]; + // Support up to x-of-3 multisig txns as standard + if (n < 1 || n > 3) + return false; + if (m < 1 || m > n) + return false; + } + + return whichType != TX_NONSTANDARD; +} + +bool ExtractDestination(const CScript& scriptPubKey, CTxDestination& addressRet) +{ + vector<valtype> vSolutions; + txnouttype whichType; + if (!Solver(scriptPubKey, whichType, vSolutions)) + return false; + + if (whichType == TX_PUBKEY) + { + addressRet = CPubKey(vSolutions[0]).GetID(); + return true; + } + else if (whichType == TX_PUBKEYHASH) + { + addressRet = CKeyID(uint160(vSolutions[0])); + return true; + } + else if (whichType == TX_SCRIPTHASH) + { + addressRet = CScriptID(uint160(vSolutions[0])); + return true; + } + // Multisig txns have more than one address... + return false; +} + +bool ExtractDestinations(const CScript& scriptPubKey, txnouttype& typeRet, vector<CTxDestination>& addressRet, int& nRequiredRet) +{ + addressRet.clear(); + typeRet = TX_NONSTANDARD; + vector<valtype> vSolutions; + if (!Solver(scriptPubKey, typeRet, vSolutions)) + return false; + if (typeRet == TX_NULL_DATA){ + // This is data, not addresses + return false; + } + + if (typeRet == TX_MULTISIG) + { + nRequiredRet = vSolutions.front()[0]; + for (unsigned int i = 1; i < vSolutions.size()-1; i++) + { + CTxDestination address = CPubKey(vSolutions[i]).GetID(); + addressRet.push_back(address); + } + } + else + { + nRequiredRet = 1; + CTxDestination address; + if (!ExtractDestination(scriptPubKey, address)) + return false; + addressRet.push_back(address); + } + + return true; +} diff --git a/src/script/standard.h b/src/script/standard.h new file mode 100644 index 0000000000..18092e879e --- /dev/null +++ b/src/script/standard.h @@ -0,0 +1,56 @@ +// Copyright (c) 2009-2010 Satoshi Nakamoto +// Copyright (c) 2009-2013 The Bitcoin developers +// Distributed under the MIT/X11 software license, see the accompanying +// file COPYING or http://www.opensource.org/licenses/mit-license.php. + +#ifndef H_BITCOIN_SCRIPT_STANDARD +#define H_BITCOIN_SCRIPT_STANDARD + +#include "script/script.h" +#include "script/interpreter.h" + +#include <stdint.h> + +class CScript; + +static const unsigned int MAX_OP_RETURN_RELAY = 40; // bytes + +// Mandatory script verification flags that all new blocks must comply with for +// them to be valid. (but old blocks may not comply with) Currently just P2SH, +// but in the future other flags may be added, such as a soft-fork to enforce +// strict DER encoding. +// +// Failing one of these tests may trigger a DoS ban - see CheckInputs() for +// details. +static const unsigned int MANDATORY_SCRIPT_VERIFY_FLAGS = SCRIPT_VERIFY_P2SH; + +// Standard script verification flags that standard transactions will comply +// with. However scripts violating these flags may still be present in valid +// blocks and we must accept those blocks. +static const unsigned int STANDARD_SCRIPT_VERIFY_FLAGS = MANDATORY_SCRIPT_VERIFY_FLAGS | + SCRIPT_VERIFY_STRICTENC | + SCRIPT_VERIFY_NULLDUMMY; + +// For convenience, standard but not mandatory verify flags. +static const unsigned int STANDARD_NOT_MANDATORY_VERIFY_FLAGS = STANDARD_SCRIPT_VERIFY_FLAGS & ~MANDATORY_SCRIPT_VERIFY_FLAGS; + +enum txnouttype +{ + TX_NONSTANDARD, + // 'standard' transaction types: + TX_PUBKEY, + TX_PUBKEYHASH, + TX_SCRIPTHASH, + TX_MULTISIG, + TX_NULL_DATA, +}; + +const char* GetTxnOutputType(txnouttype t); + +bool Solver(const CScript& scriptPubKey, txnouttype& typeRet, std::vector<std::vector<unsigned char> >& vSolutionsRet); +int ScriptSigArgsExpected(txnouttype t, const std::vector<std::vector<unsigned char> >& vSolutions); +bool IsStandard(const CScript& scriptPubKey, txnouttype& whichType); +bool ExtractDestination(const CScript& scriptPubKey, CTxDestination& addressRet); +bool ExtractDestinations(const CScript& scriptPubKey, txnouttype& typeRet, std::vector<CTxDestination>& addressRet, int& nRequiredRet); + +#endif |