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Separate script/standard
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jtimon authored and sipa committed Sep 8, 2014
1 parent da03e6e commit c4408a6
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Showing 11 changed files with 324 additions and 283 deletions.
2 changes: 2 additions & 0 deletions src/Makefile.am
Expand Up @@ -100,6 +100,7 @@ BITCOIN_CORE_H = \
rpcserver.h \
script/interpreter.h \
script/script.h \
script/standard.h \
scriptutils.h \
serialize.h \
sync.h \
Expand Down Expand Up @@ -210,6 +211,7 @@ libbitcoin_common_a_SOURCES = \
protocol.cpp \
script/interpreter.cpp \
script/script.cpp \
script/standard.cpp \
scriptutils.cpp \
$(BITCOIN_CORE_H)

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2 changes: 2 additions & 0 deletions src/bitcoin-tx.cpp
Expand Up @@ -8,6 +8,8 @@
#include "core.h"
#include "main.h" // for MAX_BLOCK_SIZE
#include "keystore.h"
#include "script/script.h"
#include "scriptutils.h"
#include "ui_interface.h" // for _(...)
#include "univalue/univalue.h"
#include "core_io.h"
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3 changes: 2 additions & 1 deletion src/bloom.cpp
Expand Up @@ -5,7 +5,8 @@
#include "bloom.h"

#include "core.h"
#include "scriptutils.h"
#include "script/script.h"
#include "script/standard.h"

#include <math.h>
#include <stdlib.h>
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3 changes: 2 additions & 1 deletion src/core_write.cpp
Expand Up @@ -4,7 +4,8 @@

#include "core_io.h"
#include "univalue/univalue.h"
#include "scriptutils.h"
#include "script/script.h"
#include "script/standard.h"
#include "core.h"
#include "serialize.h"
#include "util.h"
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3 changes: 2 additions & 1 deletion src/main.h
Expand Up @@ -15,7 +15,8 @@
#include "core.h"
#include "net.h"
#include "pow.h"
#include "scriptutils.h"
#include "script/script.h"
#include "script/standard.h"
#include "sync.h"
#include "txmempool.h"
#include "uint256.h"
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2 changes: 2 additions & 0 deletions src/rpcrawtransaction.cpp
Expand Up @@ -11,6 +11,8 @@
#include "main.h"
#include "net.h"
#include "rpcserver.h"
#include "script/script.h"
#include "script/standard.h"
#include "uint256.h"
#ifdef ENABLE_WALLET
#include "wallet.h"
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254 changes: 254 additions & 0 deletions 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;
}
56 changes: 56 additions & 0 deletions 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

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