Function ProduceSignature

src/script/sign.cpp:745–817

}

bool ProduceSignature(const SigningProvider& provider, const BaseSignatureCreator& creator, const CScript& fromPubKey, SignatureData& sigdata)
{
    if (sigdata.complete) return true;

    std::vector<valtype> result;
    TxoutType whichType;
    bool solved = SignStep(provider, creator, fromPubKey, result, whichType, SigVersion::BASE, sigdata);
    bool P2SH = false;
    CScript subscript;

    if (solved && whichType == TxoutType::SCRIPTHASH)
    {
        // Solver returns the subscript that needs to be evaluated;
        // the final scriptSig is the signatures from that
        // and then the serialized subscript:
        subscript = CScript(result[0].begin(), result[0].end());
        sigdata.redeem_script = subscript;
        solved = solved && SignStep(provider, creator, subscript, result, whichType, SigVersion::BASE, sigdata) && whichType != TxoutType::SCRIPTHASH;
        P2SH = true;
    }

    if (solved && whichType == TxoutType::WITNESS_V0_KEYHASH)
    {
        CScript witnessscript;
        witnessscript << OP_DUP << OP_HASH160 << ToByteVector(result[0]) << OP_EQUALVERIFY << OP_CHECKSIG;
        TxoutType subType;
        solved = solved && SignStep(provider, creator, witnessscript, result, subType, SigVersion::WITNESS_V0, sigdata);
        sigdata.scriptWitness.stack = result;
        sigdata.witness = true;
        result.clear();
    }
    else if (solved && whichType == TxoutType::WITNESS_V0_SCRIPTHASH)
    {
        CScript witnessscript(result[0].begin(), result[0].end());
        sigdata.witness_script = witnessscript;

        TxoutType subType{TxoutType::NONSTANDARD};
        solved = solved && SignStep(provider, creator, witnessscript, result, subType, SigVersion::WITNESS_V0, sigdata) && subType != TxoutType::SCRIPTHASH && subType != TxoutType::WITNESS_V0_SCRIPTHASH && subType != TxoutType::WITNESS_V0_KEYHASH;

        // If we couldn't find a solution with the legacy satisfier, try satisfying the script using Miniscript.
        // Note we need to check if the result stack is empty before, because it might be used even if the Script
        // isn't fully solved. For instance the CHECKMULTISIG satisfaction in SignStep() pushes partial signatures
        // and the extractor relies on this behaviour to combine witnesses.
        if (!solved && result.empty()) {
            WshSatisfier ms_satisfier{provider, sigdata, creator, witnessscript};
            const auto ms = miniscript::FromScript(witnessscript, ms_satisfier);
            solved = ms && ms->Satisfy(ms_satisfier, result) == miniscript::Availability::YES;
        }
        result.emplace_back(witnessscript.begin(), witnessscript.end());

        sigdata.scriptWitness.stack = result;
        sigdata.witness = true;
        result.clear();
    } else if (whichType == TxoutType::WITNESS_V1_TAPROOT && !P2SH) {
        sigdata.witness = true;
        if (solved) {
            sigdata.scriptWitness.stack = std::move(result);
        }