[build] Move rpc rawtransaction util functions to rpc/rawtransaction_util.cpp

rpc/rawtransaction.cpp moves to libbitcoin_server since it should not be
accessed by non-node libraries. The utility following utility methods
move to their own unit rpc/rawtransaction_util since they need to be
accessed by non-node libraries:

- `ConstructTransaction`
- `TxInErrorToJSON`
- `SignTransaction`

Author: jnewbery

src/Makefile.am

@@ -176,7 +176,7 @@ BITCOIN_CORE_H = \
   rpc/mining.h \
   rpc/protocol.h \
   rpc/server.h \
-  rpc/rawtransaction.h \
+  rpc/rawtransaction_util.h \
   rpc/register.h \
   rpc/util.h \
   scheduler.h \
@@ -439,6 +439,7 @@ libbitcoin_common_a_SOURCES = \
   policy/policy.cpp \
   protocol.cpp \
   psbt.cpp \
+  rpc/rawtransaction_util.cpp \
   rpc/util.cpp \
   scheduler.cpp \
   script/descriptor.cpp \

src/rpc/rawtransaction.cpp

@@ -20,7 +20,7 @@
 #include <policy/rbf.h>
 #include <primitives/transaction.h>
 #include <psbt.h>
-#include <rpc/rawtransaction.h>
+#include <rpc/rawtransaction_util.h>
 #include <rpc/server.h>
 #include <rpc/util.h>
 #include <script/script.h>
@@ -359,119 +359,6 @@ static UniValue verifytxoutproof(const JSONRPCRequest& request)
     return res;
 }
 
-CMutableTransaction ConstructTransaction(const UniValue& inputs_in, const UniValue& outputs_in, const UniValue& locktime, const UniValue& rbf)
-{
-    if (inputs_in.isNull() || outputs_in.isNull())
-        throw JSONRPCError(RPC_INVALID_PARAMETER, "Invalid parameter, arguments 1 and 2 must be non-null");
-
-    UniValue inputs = inputs_in.get_array();
-    const bool outputs_is_obj = outputs_in.isObject();
-    UniValue outputs = outputs_is_obj ? outputs_in.get_obj() : outputs_in.get_array();
-
-    CMutableTransaction rawTx;
-
-    if (!locktime.isNull()) {
-        int64_t nLockTime = locktime.get_int64();
-        if (nLockTime < 0 || nLockTime > LOCKTIME_MAX)
-            throw JSONRPCError(RPC_INVALID_PARAMETER, "Invalid parameter, locktime out of range");
-        rawTx.nLockTime = nLockTime;
-    }
-
-    bool rbfOptIn = rbf.isTrue();
-
-    for (unsigned int idx = 0; idx < inputs.size(); idx++) {
-        const UniValue& input = inputs[idx];
-        const UniValue& o = input.get_obj();
-
-        uint256 txid = ParseHashO(o, "txid");
-
-        const UniValue& vout_v = find_value(o, "vout");
-        if (!vout_v.isNum())
-            throw JSONRPCError(RPC_INVALID_PARAMETER, "Invalid parameter, missing vout key");
-        int nOutput = vout_v.get_int();
-        if (nOutput < 0)
-            throw JSONRPCError(RPC_INVALID_PARAMETER, "Invalid parameter, vout must be positive");
-
-        uint32_t nSequence;
-        if (rbfOptIn) {
-            nSequence = MAX_BIP125_RBF_SEQUENCE; /* CTxIn::SEQUENCE_FINAL - 2 */
-        } else if (rawTx.nLockTime) {
-            nSequence = CTxIn::SEQUENCE_FINAL - 1;
-        } else {
-            nSequence = CTxIn::SEQUENCE_FINAL;
-        }
-
-        // set the sequence number if passed in the parameters object
-        const UniValue& sequenceObj = find_value(o, "sequence");
-        if (sequenceObj.isNum()) {
-            int64_t seqNr64 = sequenceObj.get_int64();
-            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);
-    }
-
-    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);
-    }
-
-    // Duplicate checking
-    std::set<CTxDestination> destinations;
-    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");
-
-            CTxOut out(0, CScript() << OP_RETURN << data);
-            rawTx.vout.push_back(out);
-        } else {
-            CTxDestination destination = DecodeDestination(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_);
-            }
-
-            CScript scriptPubKey = GetScriptForDestination(destination);
-            CAmount nAmount = AmountFromValue(outputs[name_]);
-
-            CTxOut out(nAmount, scriptPubKey);
-            rawTx.vout.push_back(out);
-        }
-    }
-
-    if (!rbf.isNull() && rawTx.vin.size() > 0 && rbfOptIn != SignalsOptInRBF(CTransaction(rawTx))) {
-        throw JSONRPCError(RPC_INVALID_PARAMETER, "Invalid parameter combination: Sequence number(s) contradict replaceable option");
-    }
-
-    return rawTx;
-}
-
 static UniValue createrawtransaction(const JSONRPCRequest& request)
 {
     if (request.fHelp || request.params.size() < 2 || request.params.size() > 4) {
@@ -717,23 +604,6 @@ static UniValue decodescript(const JSONRPCRequest& request)
     return r;
 }
 
-/** Pushes a JSON object for script verification or signing errors to vErrorsRet. */
-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", (uint64_t)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].begin(), txin.scriptWitness.stack[i].end()));
-    }
-    entry.pushKV("witness", witness);
-    entry.pushKV("scriptSig", HexStr(txin.scriptSig.begin(), txin.scriptSig.end()));
-    entry.pushKV("sequence", (uint64_t)txin.nSequence);
-    entry.pushKV("error", strMessage);
-    vErrorsRet.push_back(entry);
-}
-
 static UniValue combinerawtransaction(const JSONRPCRequest& request)
 {
     if (request.fHelp || request.params.size() != 1)
@@ -818,152 +688,6 @@ static UniValue combinerawtransaction(const JSONRPCRequest& request)
     return EncodeHexTx(CTransaction(mergedTx));
 }
 
-// TODO(https://github.com/bitcoin/bitcoin/pull/10973#discussion_r267084237):
-// This function is called from both wallet and node rpcs
-// (signrawtransactionwithwallet and signrawtransactionwithkey). It should be
-// moved to a util file so wallet code doesn't need to link against node code.
-// Also the dependency on interfaces::Chain should be removed, so
-// signrawtransactionwithkey doesn't need access to a Chain instance.
-UniValue SignTransaction(interfaces::Chain& chain, CMutableTransaction& mtx, const UniValue& prevTxsUnival, CBasicKeyStore *keystore, bool is_temp_keystore, const UniValue& hashType)
-{
-    // Fetch previous transactions (inputs):
-    std::map<COutPoint, Coin> coins;
-    for (const CTxIn& txin : mtx.vin) {
-        coins[txin.prevout]; // Create empty map entry keyed by prevout.
-    }
-    chain.findCoins(coins);
-
-    // Add previous txouts given in the RPC call:
-    if (!prevTxsUnival.isNull()) {
-        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\"}");
-            }
-
-            UniValue prevOut = p.get_obj();
-
-            RPCTypeCheckObj(prevOut,
-                {
-                    {"txid", UniValueType(UniValue::VSTR)},
-                    {"vout", UniValueType(UniValue::VNUM)},
-                    {"scriptPubKey", UniValueType(UniValue::VSTR)},
-                });
-
-            uint256 txid = ParseHashO(prevOut, "txid");
-
-            int nOut = find_value(prevOut, "vout").get_int();
-            if (nOut < 0) {
-                throw JSONRPCError(RPC_DESERIALIZATION_ERROR, "vout must be positive");
-            }
-
-            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(find_value(prevOut, "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
-            if (is_temp_keystore && (scriptPubKey.IsPayToScriptHash() || scriptPubKey.IsPayToWitnessScriptHash())) {
-                RPCTypeCheckObj(prevOut,
-                    {
-                        {"redeemScript", UniValueType(UniValue::VSTR)},
-                        {"witnessScript", UniValueType(UniValue::VSTR)},
-                    }, true);
-                UniValue rs = find_value(prevOut, "redeemScript");
-                if (!rs.isNull()) {
-                    std::vector<unsigned char> rsData(ParseHexV(rs, "redeemScript"));
-                    CScript redeemScript(rsData.begin(), rsData.end());
-                    keystore->AddCScript(redeemScript);
-                    // Automatically also add the P2WSH wrapped version of the script (to deal with P2SH-P2WSH).
-                    // This is only for compatibility, it is encouraged to use the explicit witnessScript field instead.
-                    keystore->AddCScript(GetScriptForWitness(redeemScript));
-                }
-                UniValue ws = find_value(prevOut, "witnessScript");
-                if (!ws.isNull()) {
-                    std::vector<unsigned char> wsData(ParseHexV(ws, "witnessScript"));
-                    CScript witnessScript(wsData.begin(), wsData.end());
-                    keystore->AddCScript(witnessScript);
-                    // Automatically also add the P2WSH wrapped version of the script (to deal with P2SH-P2WSH).
-                    keystore->AddCScript(GetScriptForWitness(witnessScript));
-                }
-            }
-        }
-    }
-
-    int nHashType = ParseSighashString(hashType);
-
-    bool fHashSingle = ((nHashType & ~SIGHASH_ANYONECANPAY) == SIGHASH_SINGLE);
-
-    // Script verification errors
-    UniValue vErrors(UniValue::VARR);
-
-    // Use CTransaction for the constant parts of the
-    // transaction to avoid rehashing.
-    const CTransaction txConst(mtx);
-    // Sign what we can:
-    for (unsigned int i = 0; i < mtx.vin.size(); i++) {
-        CTxIn& txin = mtx.vin[i];
-        auto coin = coins.find(txin.prevout);
-        if (coin == coins.end() || coin->second.IsSpent()) {
-            TxInErrorToJSON(txin, vErrors, "Input not found or already spent");
-            continue;
-        }
-        const CScript& prevPubKey = coin->second.out.scriptPubKey;
-        const CAmount& amount = coin->second.out.nValue;
-
-        SignatureData sigdata = DataFromTransaction(mtx, i, coin->second.out);
-        // Only sign SIGHASH_SINGLE if there's a corresponding output:
-        if (!fHashSingle || (i < mtx.vout.size())) {
-            ProduceSignature(*keystore, MutableTransactionSignatureCreator(&mtx, i, amount, nHashType), prevPubKey, sigdata);
-        }
-
-        UpdateInput(txin, sigdata);
-
-        // amount must be specified for valid segwit signature
-        if (amount == MAX_MONEY && !txin.scriptWitness.IsNull()) {
-            throw JSONRPCError(RPC_TYPE_ERROR, strprintf("Missing amount for %s", coin->second.out.ToString()));
-        }
-
-        ScriptError serror = SCRIPT_ERR_OK;
-        if (!VerifyScript(txin.scriptSig, prevPubKey, &txin.scriptWitness, STANDARD_SCRIPT_VERIFY_FLAGS, TransactionSignatureChecker(&txConst, i, amount), &serror)) {
-            if (serror == SCRIPT_ERR_INVALID_STACK_OPERATION) {
-                // Unable to sign input and verification failed (possible attempt to partially sign).
-                TxInErrorToJSON(txin, vErrors, "Unable to sign input, invalid stack size (possibly missing key)");
-            } else {
-                TxInErrorToJSON(txin, vErrors, ScriptErrorString(serror));
-            }
-        }
-    }
-    bool fComplete = vErrors.empty();
-
-    UniValue result(UniValue::VOBJ);
-    result.pushKV("hex", EncodeHexTx(CTransaction(mtx)));
-    result.pushKV("complete", fComplete);
-    if (!vErrors.empty()) {
-        result.pushKV("errors", vErrors);
-    }
-
-    return result;
-}
-
 static UniValue signrawtransactionwithkey(const JSONRPCRequest& request)
 {
     if (request.fHelp || request.params.size() < 2 || request.params.size() > 4)