bitcoin/src/script/sign.h
Pieter Wuille d40f06a3da Introduce interface for signing providers
CKeyStore is a rich interface that provides many features, including knowledge
of scripts and pubkeys for solving, private keys for signing, in addition to
watch-only keys and scripts, and distinguishing lack of keys from them just
being encrypted.

The signing logic in script/sign does not actually need most of these features.
Here we introduce a simpler interface (SigningProvider) which *only* provides
keys and scripts. This is actually sufficient for signing.

In addtion, we swap the dependency between keystore and script/sign
(keystore now depends on script/script with CKeyStore deriving from
SigningProvider, rather than CKeyStore being the interface that signing
relies on).
2018-03-25 13:26:57 -07:00

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4.5 KiB
C++

// Copyright (c) 2009-2010 Satoshi Nakamoto
// Copyright (c) 2009-2017 The Bitcoin Core developers
// Distributed under the MIT software license, see the accompanying
// file COPYING or http://www.opensource.org/licenses/mit-license.php.
#ifndef BITCOIN_SCRIPT_SIGN_H
#define BITCOIN_SCRIPT_SIGN_H
#include <script/interpreter.h>
class CKey;
class CKeyID;
class CScript;
class CScriptID;
class CTransaction;
struct CMutableTransaction;
/** An interface to be implemented by keystores that support signing. */
class SigningProvider
{
public:
virtual ~SigningProvider() {}
virtual bool GetCScript(const CScriptID &scriptid, CScript& script) const =0;
virtual bool GetPubKey(const CKeyID &address, CPubKey& pubkey) const =0;
virtual bool GetKey(const CKeyID &address, CKey& key) const =0;
};
/** Virtual base class for signature creators. */
class BaseSignatureCreator {
protected:
const SigningProvider* m_provider;
public:
explicit BaseSignatureCreator(const SigningProvider* provider) : m_provider(provider) {}
const SigningProvider& Provider() const { return *m_provider; }
virtual ~BaseSignatureCreator() {}
virtual const BaseSignatureChecker& Checker() const =0;
/** Create a singular (non-script) signature. */
virtual bool CreateSig(std::vector<unsigned char>& vchSig, const CKeyID& keyid, const CScript& scriptCode, SigVersion sigversion) const =0;
};
/** A signature creator for transactions. */
class TransactionSignatureCreator : public BaseSignatureCreator {
const CTransaction* txTo;
unsigned int nIn;
int nHashType;
CAmount amount;
const TransactionSignatureChecker checker;
public:
TransactionSignatureCreator(const SigningProvider* provider, const CTransaction* txToIn, unsigned int nInIn, const CAmount& amountIn, int nHashTypeIn=SIGHASH_ALL);
const BaseSignatureChecker& Checker() const override { return checker; }
bool CreateSig(std::vector<unsigned char>& vchSig, const CKeyID& keyid, const CScript& scriptCode, SigVersion sigversion) const override;
};
class MutableTransactionSignatureCreator : public TransactionSignatureCreator {
CTransaction tx;
public:
MutableTransactionSignatureCreator(const SigningProvider* provider, const CMutableTransaction* txToIn, unsigned int nInIn, const CAmount& amountIn, int nHashTypeIn) : TransactionSignatureCreator(provider, &tx, nInIn, amountIn, nHashTypeIn), tx(*txToIn) {}
};
/** A signature creator that just produces 72-byte empty signatures. */
class DummySignatureCreator : public BaseSignatureCreator {
public:
explicit DummySignatureCreator(const SigningProvider* provider) : BaseSignatureCreator(provider) {}
const BaseSignatureChecker& Checker() const override;
bool CreateSig(std::vector<unsigned char>& vchSig, const CKeyID& keyid, const CScript& scriptCode, SigVersion sigversion) const override;
};
struct SignatureData {
CScript scriptSig;
CScriptWitness scriptWitness;
SignatureData() {}
explicit SignatureData(const CScript& script) : scriptSig(script) {}
};
/** Produce a script signature using a generic signature creator. */
bool ProduceSignature(const BaseSignatureCreator& creator, const CScript& scriptPubKey, SignatureData& sigdata);
/** Produce a script signature for a transaction. */
bool SignSignature(const SigningProvider &provider, const CScript& fromPubKey, CMutableTransaction& txTo, unsigned int nIn, const CAmount& amount, int nHashType);
bool SignSignature(const SigningProvider &provider, const CTransaction& txFrom, CMutableTransaction& txTo, unsigned int nIn, int nHashType);
/** Combine two script signatures using a generic signature checker, intelligently, possibly with OP_0 placeholders. */
SignatureData CombineSignatures(const CScript& scriptPubKey, const BaseSignatureChecker& checker, const SignatureData& scriptSig1, const SignatureData& scriptSig2);
/** Extract signature data from a transaction, and insert it. */
SignatureData DataFromTransaction(const CMutableTransaction& tx, unsigned int nIn);
void UpdateTransaction(CMutableTransaction& tx, unsigned int nIn, const SignatureData& data);
void UpdateInput(CTxIn& input, const SignatureData& data);
/* Check whether we know how to sign for an output like this, assuming we
* have all private keys. While this function does not need private keys, the passed
* provider is used to look up public keys and redeemscripts by hash.
* Solvability is unrelated to whether we consider this output to be ours. */
bool IsSolvable(const SigningProvider& provider, const CScript& script);
#endif // BITCOIN_SCRIPT_SIGN_H