rawtransaction_util.cpp

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// Copyright (c) 2010 Satoshi Nakamoto
// Copyright (c) 2009-present The Bitcoin Core developers
// Distributed under the MIT software license, see the accompanying
// file COPYING or http://www.opensource.org/licenses/mit-license.php.
 
#include <rpc/rawtransaction_util.h>
 
#include <coins.h>
#include <consensus/amount.h>
#include <core_io.h>
#include <key_io.h>
#include <policy/policy.h>
#include <primitives/transaction.h>
#include <rpc/request.h>
#include <rpc/util.h>
#include <script/sign.h>
#include <script/signingprovider.h>
#include <tinyformat.h>
#include <univalue.h>
#include <util/check.h>
#include <util/rbf.h>
#include <util/string.h>
#include <util/strencodings.h>
#include <util/translation.h>
 
void AddInputs(CMutableTransaction& rawTx, const UniValue& inputs_in, std::optional<bool> rbf)
{
    UniValue inputs;
    if (inputs_in.isNull()) {
        inputs = UniValue::VARR;
    } else {
        inputs = inputs_in.get_array();
    }
 
    for (unsigned int idx = 0; idx < inputs.size(); idx++) {
        const UniValue& input = inputs[idx];
        const UniValue& o = input.get_obj();
 
        Txid txid = Txid::FromUint256(ParseHashO(o, "txid"));
 
        const UniValue& vout_v = o.find_value("vout");
        if (!vout_v.isNum())
            throw JSONRPCError(RPC_INVALID_PARAMETER, "Invalid parameter, missing vout key");
        int nOutput = vout_v.getInt<int>();
        if (nOutput < 0)
            throw JSONRPCError(RPC_INVALID_PARAMETER, "Invalid parameter, vout cannot be negative");
 
        uint32_t nSequence;
 
        if (rbf.value_or(true)) {
            nSequence = MAX_BIP125_RBF_SEQUENCE; /* CTxIn::SEQUENCE_FINAL - 2 */
        } else if (rawTx.nLockTime) {
            nSequence = CTxIn::MAX_SEQUENCE_NONFINAL; /* CTxIn::SEQUENCE_FINAL - 1 */
        } else {
            nSequence = CTxIn::SEQUENCE_FINAL;
        }
 
        // set the sequence number if passed in the parameters object
        const UniValue& sequenceObj = o.find_value("sequence");
        if (sequenceObj.isNum()) {
            int64_t seqNr64 = sequenceObj.getInt<int64_t>();
            if (seqNr64 < 0 || seqNr64 > CTxIn::SEQUENCE_FINAL) {
                throw JSONRPCError(RPC_INVALID_PARAMETER, "Invalid parameter, sequence number is out of range");
            } else {
                nSequence = (uint32_t)seqNr64;
            }
        }
 
        CTxIn in(COutPoint(txid, nOutput), CScript(), nSequence);
 
        rawTx.vin.push_back(in);
    }
}
 
UniValue NormalizeOutputs(const UniValue& outputs_in)
{
    if (outputs_in.isNull()) {
        throw JSONRPCError(RPC_INVALID_PARAMETER, "Invalid parameter, output argument must be non-null");
    }
 
    const bool outputs_is_obj = outputs_in.isObject();
    UniValue outputs = outputs_is_obj ? outputs_in.get_obj() : outputs_in.get_array();
 
    if (!outputs_is_obj) {
        // Translate array of key-value pairs into dict
        UniValue outputs_dict = UniValue(UniValue::VOBJ);
        for (size_t i = 0; i < outputs.size(); ++i) {
            const UniValue& output = outputs[i];
            if (!output.isObject()) {
                throw JSONRPCError(RPC_INVALID_PARAMETER, "Invalid parameter, key-value pair not an object as expected");
            }
            if (output.size() != 1) {
                throw JSONRPCError(RPC_INVALID_PARAMETER, "Invalid parameter, key-value pair must contain exactly one key");
            }
            outputs_dict.pushKVs(output);
        }
        outputs = std::move(outputs_dict);
    }
    return outputs;
}
 
std::vector<std::pair<CTxDestination, CAmount>> ParseOutputs(const UniValue& outputs)
{
    // Duplicate checking
    std::set<CTxDestination> destinations;
    std::vector<std::pair<CTxDestination, CAmount>> parsed_outputs;
    bool has_data{false};
    for (const std::string& name_ : outputs.getKeys()) {
        if (name_ == "data") {
            if (has_data) {
                throw JSONRPCError(RPC_INVALID_PARAMETER, "Invalid parameter, duplicate key: data");
            }
            has_data = true;
            std::vector<unsigned char> data = ParseHexV(outputs[name_].getValStr(), "Data");
            CTxDestination destination{CNoDestination{CScript() << OP_RETURN << data}};
            CAmount amount{0};
            parsed_outputs.emplace_back(destination, amount);
        } else {
            CTxDestination destination{DecodeDestination(name_)};
            CAmount amount{AmountFromValue(outputs[name_])};
            if (!IsValidDestination(destination)) {
                throw JSONRPCError(RPC_INVALID_ADDRESS_OR_KEY, std::string("Invalid Bitcoin address: ") + name_);
            }
 
            if (!destinations.insert(destination).second) {
                throw JSONRPCError(RPC_INVALID_PARAMETER, std::string("Invalid parameter, duplicated address: ") + name_);
            }
            parsed_outputs.emplace_back(destination, amount);
        }
    }
    return parsed_outputs;
}
 
void AddOutputs(CMutableTransaction& rawTx, const UniValue& outputs_in)
{
    UniValue outputs(UniValue::VOBJ);
    outputs = NormalizeOutputs(outputs_in);
 
    std::vector<std::pair<CTxDestination, CAmount>> parsed_outputs = ParseOutputs(outputs);
    for (const auto& [destination, nAmount] : parsed_outputs) {
        CScript scriptPubKey = GetScriptForDestination(destination);
 
        CTxOut out(nAmount, scriptPubKey);
        rawTx.vout.push_back(out);
    }
}
 
CMutableTransaction ConstructTransaction(const UniValue& inputs_in, const UniValue& outputs_in, const UniValue& locktime, std::optional<bool> rbf, const uint32_t version)
{
    CMutableTransaction rawTx;
 
    if (!locktime.isNull()) {
        int64_t nLockTime = locktime.getInt<int64_t>();
        if (nLockTime < 0 || nLockTime > LOCKTIME_MAX)
            throw JSONRPCError(RPC_INVALID_PARAMETER, "Invalid parameter, locktime out of range");
        rawTx.nLockTime = nLockTime;
    }
 
    if (version < TX_MIN_STANDARD_VERSION || version > TX_MAX_STANDARD_VERSION) {
        throw JSONRPCError(RPC_INVALID_PARAMETER, strprintf("Invalid parameter, version out of range(%d~%d)", TX_MIN_STANDARD_VERSION, TX_MAX_STANDARD_VERSION));
    }
    rawTx.version = version;
 
    AddInputs(rawTx, inputs_in, rbf);
    AddOutputs(rawTx, outputs_in);
 
    if (rbf.has_value() && rbf.value() && rawTx.vin.size() > 0 && !SignalsOptInRBF(CTransaction(rawTx))) {
        throw JSONRPCError(RPC_INVALID_PARAMETER, "Invalid parameter combination: Sequence number(s) contradict replaceable option");
    }
 
    return rawTx;
}
 
static void TxInErrorToJSON(const CTxIn& txin, UniValue& vErrorsRet, const std::string& strMessage)
{
    UniValue entry(UniValue::VOBJ);
    entry.pushKV("txid", txin.prevout.hash.ToString());
    entry.pushKV("vout", txin.prevout.n);
    UniValue witness(UniValue::VARR);
    for (unsigned int i = 0; i < txin.scriptWitness.stack.size(); i++) {
        witness.push_back(HexStr(txin.scriptWitness.stack[i]));
    }
    entry.pushKV("witness", std::move(witness));
    entry.pushKV("scriptSig", HexStr(txin.scriptSig));
    entry.pushKV("sequence", txin.nSequence);
    entry.pushKV("error", strMessage);
    vErrorsRet.push_back(std::move(entry));
}
 
void ParsePrevouts(const UniValue& prevTxsUnival, FlatSigningProvider* keystore, std::map<COutPoint, Coin>& coins)
{
    if (!prevTxsUnival.isNull()) {
        const UniValue& prevTxs = prevTxsUnival.get_array();
        for (unsigned int idx = 0; idx < prevTxs.size(); ++idx) {
            const UniValue& p = prevTxs[idx];
            if (!p.isObject()) {
                throw JSONRPCError(RPC_DESERIALIZATION_ERROR, "expected object with {\"txid'\",\"vout\",\"scriptPubKey\"}");
            }
 
            const UniValue& prevOut = p.get_obj();
 
            RPCTypeCheckObj(prevOut,
                {
                    {"txid", UniValueType(UniValue::VSTR)},
                    {"vout", UniValueType(UniValue::VNUM)},
                    {"scriptPubKey", UniValueType(UniValue::VSTR)},
                });
 
            Txid txid = Txid::FromUint256(ParseHashO(prevOut, "txid"));
 
            int nOut = prevOut.find_value("vout").getInt<int>();
            if (nOut < 0) {
                throw JSONRPCError(RPC_DESERIALIZATION_ERROR, "vout cannot be negative");
            }
 
            COutPoint out(txid, nOut);
            std::vector<unsigned char> pkData(ParseHexO(prevOut, "scriptPubKey"));
            CScript scriptPubKey(pkData.begin(), pkData.end());
 
            {
                auto coin = coins.find(out);
                if (coin != coins.end() && !coin->second.IsSpent() && coin->second.out.scriptPubKey != scriptPubKey) {
                    std::string err("Previous output scriptPubKey mismatch:\n");
                    err = err + ScriptToAsmStr(coin->second.out.scriptPubKey) + "\nvs:\n"+
                        ScriptToAsmStr(scriptPubKey);
                    throw JSONRPCError(RPC_DESERIALIZATION_ERROR, err);
                }
                Coin newcoin;
                newcoin.out.scriptPubKey = scriptPubKey;
                newcoin.out.nValue = MAX_MONEY;
                if (prevOut.exists("amount")) {
                    newcoin.out.nValue = AmountFromValue(prevOut.find_value("amount"));
                }
                newcoin.nHeight = 1;
                coins[out] = std::move(newcoin);
            }
 
            // if redeemScript and private keys were given, add redeemScript to the keystore so it can be signed
            const bool is_p2sh = scriptPubKey.IsPayToScriptHash();
            const bool is_p2wsh = scriptPubKey.IsPayToWitnessScriptHash();
            if (keystore && (is_p2sh || is_p2wsh)) {
                RPCTypeCheckObj(prevOut,
                    {
                        {"redeemScript", UniValueType(UniValue::VSTR)},
                        {"witnessScript", UniValueType(UniValue::VSTR)},
                    }, true);
                const UniValue& rs{prevOut.find_value("redeemScript")};
                const UniValue& ws{prevOut.find_value("witnessScript")};
                if (rs.isNull() && ws.isNull()) {
                    throw JSONRPCError(RPC_INVALID_PARAMETER, "Missing redeemScript/witnessScript");
                }
 
                // work from witnessScript when possible
                std::vector<unsigned char> scriptData(!ws.isNull() ? ParseHexV(ws, "witnessScript") : ParseHexV(rs, "redeemScript"));
                CScript script(scriptData.begin(), scriptData.end());
                keystore->scripts.emplace(CScriptID(script), script);
                // Automatically also add the P2WSH wrapped version of the script (to deal with P2SH-P2WSH).
                // This is done for redeemScript only for compatibility, it is encouraged to use the explicit witnessScript field instead.
                CScript witness_output_script{GetScriptForDestination(WitnessV0ScriptHash(script))};
                keystore->scripts.emplace(CScriptID(witness_output_script), witness_output_script);
 
                if (!ws.isNull() && !rs.isNull()) {
                    // if both witnessScript and redeemScript are provided,
                    // they should either be the same (for backwards compat),
                    // or the redeemScript should be the encoded form of
                    // the witnessScript (ie, for p2sh-p2wsh)
                    if (ws.get_str() != rs.get_str()) {
                        std::vector<unsigned char> redeemScriptData(ParseHexV(rs, "redeemScript"));
                        CScript redeemScript(redeemScriptData.begin(), redeemScriptData.end());
                        if (redeemScript != witness_output_script) {
                            throw JSONRPCError(RPC_INVALID_PARAMETER, "redeemScript does not correspond to witnessScript");
                        }
                    }
                }
 
                if (is_p2sh) {
                    const CTxDestination p2sh{ScriptHash(script)};
                    const CTxDestination p2sh_p2wsh{ScriptHash(witness_output_script)};
                    if (scriptPubKey == GetScriptForDestination(p2sh)) {
                        // traditional p2sh; arguably an error if
                        // we got here with rs.IsNull(), because
                        // that means the p2sh script was specified
                        // via witnessScript param, but for now
                        // we'll just quietly accept it
                    } else if (scriptPubKey == GetScriptForDestination(p2sh_p2wsh)) {
                        // p2wsh encoded as p2sh; ideally the witness
                        // script was specified in the witnessScript
                        // param, but also support specifying it via
                        // redeemScript param for backwards compat
                        // (in which case ws.IsNull() == true)
                    } else {
                        // otherwise, can't generate scriptPubKey from
                        // either script, so we got unusable parameters
                        throw JSONRPCError(RPC_INVALID_PARAMETER, "redeemScript/witnessScript does not match scriptPubKey");
                    }
                } else if (is_p2wsh) {
                    // plain p2wsh; could throw an error if script
                    // was specified by redeemScript rather than
                    // witnessScript (ie, ws.IsNull() == true), but
                    // accept it for backwards compat
                    const CTxDestination p2wsh{WitnessV0ScriptHash(script)};
                    if (scriptPubKey != GetScriptForDestination(p2wsh)) {
                        throw JSONRPCError(RPC_INVALID_PARAMETER, "redeemScript/witnessScript does not match scriptPubKey");
                    }
                }
            }
        }
    }
}
 
void SignTransaction(CMutableTransaction& mtx, const SigningProvider* keystore, const std::map<COutPoint, Coin>& coins, const UniValue& hashType, UniValue& result)
{
    std::optional<int> nHashType = ParseSighashString(hashType);
    if (!nHashType) {
        nHashType = SIGHASH_DEFAULT;
    }
 
    // Script verification errors
    std::map<int, bilingual_str> input_errors;
 
    bool complete = SignTransaction(mtx, keystore, coins, {.sighash_type = *nHashType}, input_errors);
    SignTransactionResultToJSON(mtx, complete, coins, input_errors, result);
}
 
void SignTransactionResultToJSON(CMutableTransaction& mtx, bool complete, const std::map<COutPoint, Coin>& coins, const std::map<int, bilingual_str>& input_errors, UniValue& result)
{
    // Make errors UniValue
    UniValue vErrors(UniValue::VARR);
    for (const auto& err_pair : input_errors) {
        if (err_pair.second.original == "Missing amount") {
            // This particular error needs to be an exception for some reason
            throw JSONRPCError(RPC_TYPE_ERROR, strprintf("Missing amount for %s", coins.at(mtx.vin.at(err_pair.first).prevout).out.ToString()));
        }
        TxInErrorToJSON(mtx.vin.at(err_pair.first), vErrors, err_pair.second.original);
    }
 
    result.pushKV("hex", EncodeHexTx(CTransaction(mtx)));
    result.pushKV("complete", complete);
    if (!vErrors.empty()) {
        if (result.exists("errors")) {
            vErrors.push_backV(result["errors"].getValues());
        }
        result.pushKV("errors", std::move(vErrors));
    }
}
 
std::vector<RPCResult> TxDoc(const TxDocOptions& opts)
{
    CHECK_NONFATAL(!opts.fee_doc || opts.fee);
    CHECK_NONFATAL(!opts.prevout_doc || opts.prevout);
    CHECK_NONFATAL(!opts.vin_item_doc || opts.vin_inner_elision);
    CHECK_NONFATAL(opts.elision_mode != ElisionMode::WithSummary || opts.elision_summary.has_value());
 
    const std::string fee_doc{opts.fee_doc.value_or(
        "transaction fee in " + CURRENCY_UNIT + ", omitted if block undo data is not available")};
    const std::string prevout_doc{opts.prevout_doc.value_or(
        "The previous output, omitted if block undo data is not available")};
    const std::string vin_item_doc{opts.vin_item_doc.value_or("utxo being spent")};
 
    auto vin_inner = std::vector<RPCResult>{
        {RPCResult::Type::STR_HEX, "coinbase", /*optional=*/true, "The coinbase value (only if coinbase transaction)"},
        {RPCResult::Type::STR_HEX, "txid", /*optional=*/true, "The transaction id (if not coinbase transaction)"},
        {RPCResult::Type::NUM, "vout", /*optional=*/true, "The output number (if not coinbase transaction)"},
        {RPCResult::Type::OBJ, "scriptSig", /*optional=*/true, "The script (if not coinbase transaction)",
        {
            {RPCResult::Type::STR, "asm", "Disassembly of the signature script"},
            {RPCResult::Type::STR_HEX, "hex", "The raw signature script bytes, hex-encoded"},
        }},
        {RPCResult::Type::ARR, "txinwitness", /*optional=*/true, "",
        {
            {RPCResult::Type::STR_HEX, "hex", "hex-encoded witness data (if any)"},
        }},
    };
    if (opts.prevout) {
        vin_inner.emplace_back(
            RPCResult::Type::OBJ, "prevout", opts.prevout_optional, prevout_doc,
            std::vector<RPCResult>{
                {RPCResult::Type::BOOL, "generated", "Coinbase or not"},
                {RPCResult::Type::NUM, "height", "The height of the prevout"},
                {RPCResult::Type::STR_AMOUNT, "value", "The value in " + CURRENCY_UNIT},
                {RPCResult::Type::OBJ, "scriptPubKey", "", ScriptPubKeyDoc()},
            }
        );
    }
    vin_inner.emplace_back(RPCResult::Type::NUM, "sequence", "The script sequence number");
 
    if (opts.vin_inner_elision) {
        vin_inner = ElideGroup(std::move(vin_inner), *opts.vin_inner_elision);
        if (opts.prevout) {
            // prevout remains visible even when other fields are elided
            std::vector<RPCResult> new_vin;
            new_vin.reserve(vin_inner.size());
            for (const auto& r : vin_inner) {
                if (r.m_key_name == "prevout") {
                    RPCResultOptions unopts = r.m_opts;
                    unopts.print_elision = HelpElisionNone{};
                    new_vin.emplace_back(r, std::move(unopts));
                } else {
                    new_vin.push_back(r);
                }
            }
            vin_inner = std::move(new_vin);
        }
    }
 
    auto fields = std::vector<RPCResult>{
        {RPCResult::Type::STR_HEX, "txid", opts.txid_field_doc},
        {RPCResult::Type::STR_HEX, "hash", "The transaction hash (differs from txid for witness transactions)"},
        {RPCResult::Type::NUM, "size", "The serialized transaction size"},
        {RPCResult::Type::NUM, "vsize", "The virtual transaction size (differs from size for witness transactions)"},
        {RPCResult::Type::NUM, "weight", "The transaction's weight (between vsize*4-3 and vsize*4)"},
        {RPCResult::Type::NUM, "version", "The version"},
        {RPCResult::Type::NUM_TIME, "locktime", "The lock time"},
        {RPCResult::Type::ARR, "vin", "",
        {
            {RPCResult::Type::OBJ, "", opts.vin_inner_elision ? vin_item_doc : "", std::move(vin_inner)},
        }},
        {RPCResult::Type::ARR, "vout", "",
        {
            {RPCResult::Type::OBJ, "", "", Cat(
                {
                    {RPCResult::Type::STR_AMOUNT, "value", "The value in " + CURRENCY_UNIT},
                    {RPCResult::Type::NUM, "n", "index"},
                    {RPCResult::Type::OBJ, "scriptPubKey", "", ScriptPubKeyDoc()},
                },
                opts.wallet ?
                    std::vector<RPCResult>{{RPCResult::Type::BOOL, "ischange", /*optional=*/true, "Output script is change (only present if true)"}} :
                    std::vector<RPCResult>{}
            )},
        }},
    };
 
    if (opts.fee) fields.emplace_back(RPCResult::Type::NUM, "fee", /*optional=*/true, fee_doc);
    if (opts.hex) fields.emplace_back(RPCResult::Type::STR_HEX, "hex", "The hex-encoded transaction data");
 
    if (opts.elision_mode != ElisionMode::None) {
        const bool silent = opts.elision_mode == ElisionMode::Silent;
        std::vector<RPCResult> new_fields;
        new_fields.reserve(fields.size());
        bool first = true;
        for (const auto& f : fields) {
            if (!silent && f.m_key_name == "fee") {
                new_fields.push_back(f);
                continue;
            }
            if (f.m_key_name == "vin" && opts.vin_inner_elision) {
                new_fields.push_back(f);
                continue;
            }
            if (!silent && first) {
                RPCResultOptions eopts = f.m_opts;
                eopts.print_elision = opts.elision_summary.value_or("");
                new_fields.emplace_back(f, std::move(eopts));
                first = false;
            } else {
                RPCResultOptions eopts = f.m_opts;
                eopts.print_elision = HelpElisionSkip{};
                new_fields.emplace_back(f, std::move(eopts));
            }
        }
        fields = std::move(new_fields);
    }
 
    return fields;
}