RPCHelpers.cpp

#include <xrpld/app/ledger/LedgerMaster.h>
#include <xrpld/app/ledger/LedgerToJson.h>
#include <xrpld/app/ledger/OpenLedger.h>
#include <xrpld/app/misc/Transaction.h>
#include <xrpld/app/paths/TrustLine.h>
#include <xrpld/app/rdb/RelationalDatabase.h>
#include <xrpld/app/tx/detail/NFTokenUtils.h>
#include <xrpld/rpc/Context.h>
#include <xrpld/rpc/DeliveredAmount.h>
#include <xrpld/rpc/detail/RPCHelpers.h>
 
#include <xrpl/ledger/View.h>
#include <xrpl/protocol/AccountID.h>
#include <xrpl/protocol/RPCErr.h>
#include <xrpl/protocol/nftPageMask.h>
#include <xrpl/resource/Fees.h>
 
#include <boost/algorithm/string/case_conv.hpp>
#include <boost/algorithm/string/predicate.hpp>
 
namespace ripple {
namespace RPC {
 
std::optional<AccountID>
accountFromStringStrict(std::string const& account)
{
    std::optional<AccountID> result;
 
    auto const publicKey =
        parseBase58<PublicKey>(TokenType::AccountPublic, account);
 
    if (publicKey)
        result = calcAccountID(*publicKey);
    else
        result = parseBase58<AccountID>(account);
 
    return result;
}
 
error_code_i
accountFromStringWithCode(
    AccountID& result,
    std::string const& strIdent,
    bool bStrict)
{
    if (auto accountID = accountFromStringStrict(strIdent))
    {
        result = *accountID;
        return rpcSUCCESS;
    }
 
    if (bStrict)
        return rpcACT_MALFORMED;
 
    // We allow the use of the seeds which is poor practice
    // and merely for debugging convenience.
    auto const seed = parseGenericSeed(strIdent);
 
    if (!seed)
        return rpcBAD_SEED;
 
    auto const keypair = generateKeyPair(KeyType::secp256k1, *seed);
 
    result = calcAccountID(keypair.first);
    return rpcSUCCESS;
}
 
Json::Value
accountFromString(AccountID& result, std::string const& strIdent, bool bStrict)
{
    error_code_i code = accountFromStringWithCode(result, strIdent, bStrict);
    if (code != rpcSUCCESS)
        return rpcError(code);
    else
        return Json::objectValue;
}
 
std::uint64_t
getStartHint(std::shared_ptr<SLE const> const& sle, AccountID const& accountID)
{
    if (sle->getType() == ltRIPPLE_STATE)
    {
        if (sle->getFieldAmount(sfLowLimit).getIssuer() == accountID)
            return sle->getFieldU64(sfLowNode);
        else if (sle->getFieldAmount(sfHighLimit).getIssuer() == accountID)
            return sle->getFieldU64(sfHighNode);
    }
 
    if (!sle->isFieldPresent(sfOwnerNode))
        return 0;
 
    return sle->getFieldU64(sfOwnerNode);
}
 
bool
isRelatedToAccount(
    ReadView const& ledger,
    std::shared_ptr<SLE const> const& sle,
    AccountID const& accountID)
{
    if (sle->getType() == ltRIPPLE_STATE)
    {
        return (sle->getFieldAmount(sfLowLimit).getIssuer() == accountID) ||
            (sle->getFieldAmount(sfHighLimit).getIssuer() == accountID);
    }
    else if (sle->isFieldPresent(sfAccount))
    {
        // If there's an sfAccount present, also test the sfDestination, if
        // present. This will match objects such as Escrows (ltESCROW), Payment
        // Channels (ltPAYCHAN), and Checks (ltCHECK) because those are added to
        // the Destination account's directory. It intentionally EXCLUDES
        // NFToken Offers (ltNFTOKEN_OFFER). NFToken Offers are NOT added to the
        // Destination account's directory.
        return sle->getAccountID(sfAccount) == accountID ||
            (sle->isFieldPresent(sfDestination) &&
             sle->getAccountID(sfDestination) == accountID);
    }
    else if (sle->getType() == ltSIGNER_LIST)
    {
        Keylet const accountSignerList = keylet::signers(accountID);
        return sle->key() == accountSignerList.key;
    }
    else if (sle->getType() == ltNFTOKEN_OFFER)
    {
        // Do not check the sfDestination field. NFToken Offers are NOT added to
        // the Destination account's directory.
        return sle->getAccountID(sfOwner) == accountID;
    }
 
    return false;
}
 
bool
getAccountObjects(
    ReadView const& ledger,
    AccountID const& account,
    std::optional<std::vector<LedgerEntryType>> const& typeFilter,
    uint256 dirIndex,
    uint256 entryIndex,
    std::uint32_t const limit,
    Json::Value& jvResult)
{
    // check if dirIndex is valid
    if (!dirIndex.isZero() && !ledger.read({ltDIR_NODE, dirIndex}))
        return false;
 
    auto typeMatchesFilter = [](std::vector<LedgerEntryType> const& typeFilter,
                                LedgerEntryType ledgerType) {
        auto it = std::find(typeFilter.begin(), typeFilter.end(), ledgerType);
        return it != typeFilter.end();
    };
 
    // if dirIndex != 0, then all NFTs have already been returned.  only
    // iterate NFT pages if the filter says so AND dirIndex == 0
    bool iterateNFTPages =
        (!typeFilter.has_value() ||
         typeMatchesFilter(typeFilter.value(), ltNFTOKEN_PAGE)) &&
        dirIndex == beast::zero;
 
    Keylet const firstNFTPage = keylet::nftpage_min(account);
 
    // we need to check the marker to see if it is an NFTTokenPage index.
    if (iterateNFTPages && entryIndex != beast::zero)
    {
        // if it is we will try to iterate the pages up to the limit
        // and then change over to the owner directory
 
        if (firstNFTPage.key != (entryIndex & ~nft::pageMask))
            iterateNFTPages = false;
    }
 
    auto& jvObjects = (jvResult[jss::account_objects] = Json::arrayValue);
 
    // this is a mutable version of limit, used to seamlessly switch
    // to iterating directory entries when nftokenpages are exhausted
    uint32_t mlimit = limit;
 
    // iterate NFTokenPages preferentially
    if (iterateNFTPages)
    {
        Keylet const first = entryIndex == beast::zero
            ? firstNFTPage
            : Keylet{ltNFTOKEN_PAGE, entryIndex};
 
        Keylet const last = keylet::nftpage_max(account);
 
        // current key
        uint256 ck = ledger.succ(first.key, last.key.next()).value_or(last.key);
 
        // current page
        auto cp = ledger.read(Keylet{ltNFTOKEN_PAGE, ck});
 
        while (cp)
        {
            jvObjects.append(cp->getJson(JsonOptions::none));
            auto const npm = (*cp)[~sfNextPageMin];
            if (npm)
                cp = ledger.read(Keylet(ltNFTOKEN_PAGE, *npm));
            else
                cp = nullptr;
 
            if (--mlimit == 0)
            {
                if (cp)
                {
                    jvResult[jss::limit] = limit;
                    jvResult[jss::marker] = std::string("0,") + to_string(ck);
                    return true;
                }
            }
 
            if (!npm)
                break;
 
            ck = *npm;
        }
 
        // if execution reaches here then we're about to transition
        // to iterating the root directory (and the conventional
        // behaviour of this RPC function.) Therefore we should
        // zero entryIndex so as not to terribly confuse things.
        entryIndex = beast::zero;
    }
 
    auto const root = keylet::ownerDir(account);
    auto found = false;
 
    if (dirIndex.isZero())
    {
        dirIndex = root.key;
        found = true;
    }
 
    auto dir = ledger.read({ltDIR_NODE, dirIndex});
    if (!dir)
    {
        // it's possible the user had nftoken pages but no
        // directory entries. If there's no nftoken page, we will
        // give empty array for account_objects.
        if (mlimit >= limit)
            jvResult[jss::account_objects] = Json::arrayValue;
 
        // non-zero dirIndex validity was checked in the beginning of this
        // function; by this point, it should be zero. This function returns
        // true regardless of nftoken page presence; if absent, account_objects
        // is already set as an empty array. Notice we will only return false in
        // this function when entryIndex can not be found, indicating an invalid
        // marker error.
        return true;
    }
 
    std::uint32_t i = 0;
    for (;;)
    {
        auto const& entries = dir->getFieldV256(sfIndexes);
        auto iter = entries.begin();
 
        if (!found)
        {
            iter = std::find(iter, entries.end(), entryIndex);
            if (iter == entries.end())
                return false;
 
            found = true;
        }
 
        // it's possible that the returned NFTPages exactly filled the
        // response.  Check for that condition.
        if (i == mlimit && mlimit < limit)
        {
            jvResult[jss::limit] = limit;
            jvResult[jss::marker] =
                to_string(dirIndex) + ',' + to_string(*iter);
            return true;
        }
 
        for (; iter != entries.end(); ++iter)
        {
            auto const sleNode = ledger.read(keylet::child(*iter));
 
            if (!typeFilter.has_value() ||
                typeMatchesFilter(typeFilter.value(), sleNode->getType()))
            {
                jvObjects.append(sleNode->getJson(JsonOptions::none));
            }
 
            if (++i == mlimit)
            {
                if (++iter != entries.end())
                {
                    jvResult[jss::limit] = limit;
                    jvResult[jss::marker] =
                        to_string(dirIndex) + ',' + to_string(*iter);
                    return true;
                }
 
                break;
            }
        }
 
        auto const nodeIndex = dir->getFieldU64(sfIndexNext);
        if (nodeIndex == 0)
            return true;
 
        dirIndex = keylet::page(root, nodeIndex).key;
        dir = ledger.read({ltDIR_NODE, dirIndex});
        if (!dir)
            return true;
 
        if (i == mlimit)
        {
            auto const& e = dir->getFieldV256(sfIndexes);
            if (!e.empty())
            {
                jvResult[jss::limit] = limit;
                jvResult[jss::marker] =
                    to_string(dirIndex) + ',' + to_string(*e.begin());
            }
 
            return true;
        }
    }
}
 
namespace {
 
bool
isValidatedOld(LedgerMaster& ledgerMaster, bool standalone)
{
    if (standalone)
        return false;
 
    return ledgerMaster.getValidatedLedgerAge() > Tuning::maxValidatedLedgerAge;
}
 
template <class T>
Status
ledgerFromRequest(T& ledger, JsonContext& context)
{
    ledger.reset();
 
    auto& params = context.params;
 
    auto indexValue = params[jss::ledger_index];
    auto hashValue = params[jss::ledger_hash];
 
    // We need to support the legacy "ledger" field.
    auto& legacyLedger = params[jss::ledger];
    if (legacyLedger)
    {
        if (legacyLedger.asString().size() > 12)
            hashValue = legacyLedger;
        else
            indexValue = legacyLedger;
    }
 
    if (!hashValue.isNull())
    {
        if (!hashValue.isString())
            return {rpcINVALID_PARAMS, "ledgerHashNotString"};
 
        uint256 ledgerHash;
        if (!ledgerHash.parseHex(hashValue.asString()))
            return {rpcINVALID_PARAMS, "ledgerHashMalformed"};
        return getLedger(ledger, ledgerHash, context);
    }
 
    if (!indexValue.isConvertibleTo(Json::stringValue))
        return {rpcINVALID_PARAMS, "ledgerIndexMalformed"};
 
    auto const index = indexValue.asString();
 
    if (index == "current" || index.empty())
        return getLedger(ledger, LedgerShortcut::CURRENT, context);
 
    if (index == "validated")
        return getLedger(ledger, LedgerShortcut::VALIDATED, context);
 
    if (index == "closed")
        return getLedger(ledger, LedgerShortcut::CLOSED, context);
 
    std::uint32_t val;
    if (!beast::lexicalCastChecked(val, index))
        return {rpcINVALID_PARAMS, "ledgerIndexMalformed"};
 
    return getLedger(ledger, val, context);
}
}  // namespace
 
template <class T, class R>
Status
ledgerFromRequest(T& ledger, GRPCContext<R>& context)
{
    R& request = context.params;
    return ledgerFromSpecifier(ledger, request.ledger(), context);
}
 
// explicit instantiation of above function
template Status
ledgerFromRequest<>(
    std::shared_ptr<ReadView const>&,
    GRPCContext<org::xrpl::rpc::v1::GetLedgerEntryRequest>&);
 
// explicit instantiation of above function
template Status
ledgerFromRequest<>(
    std::shared_ptr<ReadView const>&,
    GRPCContext<org::xrpl::rpc::v1::GetLedgerDataRequest>&);
 
// explicit instantiation of above function
template Status
ledgerFromRequest<>(
    std::shared_ptr<ReadView const>&,
    GRPCContext<org::xrpl::rpc::v1::GetLedgerRequest>&);
 
template <class T>
Status
ledgerFromSpecifier(
    T& ledger,
    org::xrpl::rpc::v1::LedgerSpecifier const& specifier,
    Context& context)
{
    ledger.reset();
 
    using LedgerCase = org::xrpl::rpc::v1::LedgerSpecifier::LedgerCase;
    LedgerCase ledgerCase = specifier.ledger_case();
    switch (ledgerCase)
    {
        case LedgerCase::kHash: {
            if (auto hash = uint256::fromVoidChecked(specifier.hash()))
            {
                return getLedger(ledger, *hash, context);
            }
            return {rpcINVALID_PARAMS, "ledgerHashMalformed"};
        }
        case LedgerCase::kSequence:
            return getLedger(ledger, specifier.sequence(), context);
        case LedgerCase::kShortcut:
            [[fallthrough]];
        case LedgerCase::LEDGER_NOT_SET: {
            auto const shortcut = specifier.shortcut();
            if (shortcut ==
                org::xrpl::rpc::v1::LedgerSpecifier::SHORTCUT_VALIDATED)
            {
                return getLedger(ledger, LedgerShortcut::VALIDATED, context);
            }
            else
            {
                if (shortcut ==
                        org::xrpl::rpc::v1::LedgerSpecifier::SHORTCUT_CURRENT ||
                    shortcut ==
                        org::xrpl::rpc::v1::LedgerSpecifier::
                            SHORTCUT_UNSPECIFIED)
                {
                    return getLedger(ledger, LedgerShortcut::CURRENT, context);
                }
                else if (
                    shortcut ==
                    org::xrpl::rpc::v1::LedgerSpecifier::SHORTCUT_CLOSED)
                {
                    return getLedger(ledger, LedgerShortcut::CLOSED, context);
                }
            }
        }
    }
 
    return Status::OK;
}
 
template <class T>
Status
getLedger(T& ledger, uint256 const& ledgerHash, Context& context)
{
    ledger = context.ledgerMaster.getLedgerByHash(ledgerHash);
    if (ledger == nullptr)
        return {rpcLGR_NOT_FOUND, "ledgerNotFound"};
    return Status::OK;
}
 
template <class T>
Status
getLedger(T& ledger, uint32_t ledgerIndex, Context& context)
{
    ledger = context.ledgerMaster.getLedgerBySeq(ledgerIndex);
    if (ledger == nullptr)
    {
        auto cur = context.ledgerMaster.getCurrentLedger();
        if (cur->info().seq == ledgerIndex)
        {
            ledger = cur;
        }
    }
 
    if (ledger == nullptr)
        return {rpcLGR_NOT_FOUND, "ledgerNotFound"};
 
    if (ledger->info().seq > context.ledgerMaster.getValidLedgerIndex() &&
        isValidatedOld(context.ledgerMaster, context.app.config().standalone()))
    {
        ledger.reset();
        if (context.apiVersion == 1)
            return {rpcNO_NETWORK, "InsufficientNetworkMode"};
        return {rpcNOT_SYNCED, "notSynced"};
    }
 
    return Status::OK;
}
 
template <class T>
Status
getLedger(T& ledger, LedgerShortcut shortcut, Context& context)
{
    if (isValidatedOld(context.ledgerMaster, context.app.config().standalone()))
    {
        if (context.apiVersion == 1)
            return {rpcNO_NETWORK, "InsufficientNetworkMode"};
        return {rpcNOT_SYNCED, "notSynced"};
    }
 
    if (shortcut == LedgerShortcut::VALIDATED)
    {
        ledger = context.ledgerMaster.getValidatedLedger();
        if (ledger == nullptr)
        {
            if (context.apiVersion == 1)
                return {rpcNO_NETWORK, "InsufficientNetworkMode"};
            return {rpcNOT_SYNCED, "notSynced"};
        }
 
        XRPL_ASSERT(
            !ledger->open(), "ripple::RPC::getLedger : validated is not open");
    }
    else
    {
        if (shortcut == LedgerShortcut::CURRENT)
        {
            ledger = context.ledgerMaster.getCurrentLedger();
            XRPL_ASSERT(
                ledger->open(), "ripple::RPC::getLedger : current is open");
        }
        else if (shortcut == LedgerShortcut::CLOSED)
        {
            ledger = context.ledgerMaster.getClosedLedger();
            XRPL_ASSERT(
                !ledger->open(), "ripple::RPC::getLedger : closed is not open");
        }
        else
        {
            return {rpcINVALID_PARAMS, "ledgerIndexMalformed"};
        }
 
        if (ledger == nullptr)
        {
            if (context.apiVersion == 1)
                return {rpcNO_NETWORK, "InsufficientNetworkMode"};
            return {rpcNOT_SYNCED, "notSynced"};
        }
 
        static auto const minSequenceGap = 10;
 
        if (ledger->info().seq + minSequenceGap <
            context.ledgerMaster.getValidLedgerIndex())
        {
            ledger.reset();
            if (context.apiVersion == 1)
                return {rpcNO_NETWORK, "InsufficientNetworkMode"};
            return {rpcNOT_SYNCED, "notSynced"};
        }
    }
    return Status::OK;
}
 
// Explicit instantiation of above three functions
template Status
getLedger<>(std::shared_ptr<ReadView const>&, uint32_t, Context&);
 
template Status
getLedger<>(
    std::shared_ptr<ReadView const>&,
    LedgerShortcut shortcut,
    Context&);
 
template Status
getLedger<>(std::shared_ptr<ReadView const>&, uint256 const&, Context&);
 
// The previous version of the lookupLedger command would accept the
// "ledger_index" argument as a string and silently treat it as a request to
// return the current ledger which, while not strictly wrong, could cause a lot
// of confusion.
//
// The code now robustly validates the input and ensures that the only possible
// values for the "ledger_index" parameter are the index of a ledger passed as
// an integer or one of the strings "current", "closed" or "validated".
// Additionally, the code ensures that the value passed in "ledger_hash" is a
// string and a valid hash. Invalid values will return an appropriate error
// code.
//
// In the absence of the "ledger_hash" or "ledger_index" parameters, the code
// assumes that "ledger_index" has the value "current".
//
// Returns a Json::objectValue.  If there was an error, it will be in that
// return value.  Otherwise, the object contains the field "validated" and
// optionally the fields "ledger_hash", "ledger_index" and
// "ledger_current_index", if they are defined.
Status
lookupLedger(
    std::shared_ptr<ReadView const>& ledger,
    JsonContext& context,
    Json::Value& result)
{
    if (auto status = ledgerFromRequest(ledger, context))
        return status;
 
    auto& info = ledger->info();
 
    if (!ledger->open())
    {
        result[jss::ledger_hash] = to_string(info.hash);
        result[jss::ledger_index] = info.seq;
    }
    else
    {
        result[jss::ledger_current_index] = info.seq;
    }
 
    result[jss::validated] = context.ledgerMaster.isValidated(*ledger);
    return Status::OK;
}
 
Json::Value
lookupLedger(std::shared_ptr<ReadView const>& ledger, JsonContext& context)
{
    Json::Value result;
    if (auto status = lookupLedger(ledger, context, result))
        status.inject(result);
 
    return result;
}
 
hash_set<AccountID>
parseAccountIds(Json::Value const& jvArray)
{
    hash_set<AccountID> result;
    for (auto const& jv : jvArray)
    {
        if (!jv.isString())
            return hash_set<AccountID>();
        auto const id = parseBase58<AccountID>(jv.asString());
        if (!id)
            return hash_set<AccountID>();
        result.insert(*id);
    }
    return result;
}
 
void
injectSLE(Json::Value& jv, SLE const& sle)
{
    jv = sle.getJson(JsonOptions::none);
    if (sle.getType() == ltACCOUNT_ROOT)
    {
        if (sle.isFieldPresent(sfEmailHash))
        {
            auto const& hash = sle.getFieldH128(sfEmailHash);
            Blob const b(hash.begin(), hash.end());
            std::string md5 = strHex(makeSlice(b));
            boost::to_lower(md5);
            // VFALCO TODO Give a name and move this constant
            //             to a more visible location. Also
            //             shouldn't this be https?
            jv[jss::urlgravatar] =
                str(boost::format("http://www.gravatar.com/avatar/%s") % md5);
        }
    }
    else
    {
        jv[jss::Invalid] = true;
    }
}
 
std::optional<Json::Value>
readLimitField(
    unsigned int& limit,
    Tuning::LimitRange const& range,
    JsonContext const& context)
{
    limit = range.rdefault;
    if (!context.params.isMember(jss::limit) ||
        context.params[jss::limit].isNull())
        return std::nullopt;
 
    auto const& jvLimit = context.params[jss::limit];
    if (!(jvLimit.isUInt() || (jvLimit.isInt() && jvLimit.asInt() >= 0)))
        return RPC::expected_field_error(jss::limit, "unsigned integer");
 
    limit = jvLimit.asUInt();
    if (limit == 0)
        return RPC::invalid_field_error(jss::limit);
 
    if (!isUnlimited(context.role))
        limit = std::max(range.rmin, std::min(range.rmax, limit));
 
    return std::nullopt;
}
 
std::optional<Seed>
parseRippleLibSeed(Json::Value const& value)
{
    // ripple-lib encodes seed used to generate an Ed25519 wallet in a
    // non-standard way. While rippled never encode seeds that way, we
    // try to detect such keys to avoid user confusion.
    if (!value.isString())
        return std::nullopt;
 
    auto const result = decodeBase58Token(value.asString(), TokenType::None);
 
    if (result.size() == 18 &&
        static_cast<std::uint8_t>(result[0]) == std::uint8_t(0xE1) &&
        static_cast<std::uint8_t>(result[1]) == std::uint8_t(0x4B))
        return Seed(makeSlice(result.substr(2)));
 
    return std::nullopt;
}
 
std::optional<Seed>
getSeedFromRPC(Json::Value const& params, Json::Value& error)
{
    using string_to_seed_t =
        std::function<std::optional<Seed>(std::string const&)>;
    using seed_match_t = std::pair<char const*, string_to_seed_t>;
 
    static seed_match_t const seedTypes[]{
        {jss::passphrase.c_str(),
         [](std::string const& s) { return parseGenericSeed(s); }},
        {jss::seed.c_str(),
         [](std::string const& s) { return parseBase58<Seed>(s); }},
        {jss::seed_hex.c_str(), [](std::string const& s) {
             uint128 i;
             if (i.parseHex(s))
                 return std::optional<Seed>(Slice(i.data(), i.size()));
             return std::optional<Seed>{};
         }}};
 
    // Identify which seed type is in use.
    seed_match_t const* seedType = nullptr;
    int count = 0;
    for (auto const& t : seedTypes)
    {
        if (params.isMember(t.first))
        {
            ++count;
            seedType = &t;
        }
    }
 
    if (count != 1)
    {
        error = RPC::make_param_error(
            "Exactly one of the following must be specified: " +
            std::string(jss::passphrase) + ", " + std::string(jss::seed) +
            " or " + std::string(jss::seed_hex));
        return std::nullopt;
    }
 
    // Make sure a string is present
    auto const& param = params[seedType->first];
    if (!param.isString())
    {
        error = RPC::expected_field_error(seedType->first, "string");
        return std::nullopt;
    }
 
    auto const fieldContents = param.asString();
 
    // Convert string to seed.
    std::optional<Seed> seed = seedType->second(fieldContents);
 
    if (!seed)
        error = rpcError(rpcBAD_SEED);
 
    return seed;
}
 
std::optional<std::pair<PublicKey, SecretKey>>
keypairForSignature(
    Json::Value const& params,
    Json::Value& error,
    unsigned int apiVersion)
{
    bool const has_key_type = params.isMember(jss::key_type);
 
    // All of the secret types we allow, but only one at a time.
    static char const* const secretTypes[]{
        jss::passphrase.c_str(),
        jss::secret.c_str(),
        jss::seed.c_str(),
        jss::seed_hex.c_str()};
 
    // Identify which secret type is in use.
    char const* secretType = nullptr;
    int count = 0;
    for (auto t : secretTypes)
    {
        if (params.isMember(t))
        {
            ++count;
            secretType = t;
        }
    }
 
    if (count == 0 || secretType == nullptr)
    {
        error = RPC::missing_field_error(jss::secret);
        return {};
    }
 
    if (count > 1)
    {
        error = RPC::make_param_error(
            "Exactly one of the following must be specified: " +
            std::string(jss::passphrase) + ", " + std::string(jss::secret) +
            ", " + std::string(jss::seed) + " or " +
            std::string(jss::seed_hex));
        return {};
    }
 
    std::optional<KeyType> keyType;
    std::optional<Seed> seed;
 
    if (has_key_type)
    {
        if (!params[jss::key_type].isString())
        {
            error = RPC::expected_field_error(jss::key_type, "string");
            return {};
        }
 
        keyType = keyTypeFromString(params[jss::key_type].asString());
 
        if (!keyType)
        {
            if (apiVersion > 1u)
                error = RPC::make_error(rpcBAD_KEY_TYPE);
            else
                error = RPC::invalid_field_error(jss::key_type);
            return {};
        }
 
        // using strcmp as pointers may not match (see
        // https://developercommunity.visualstudio.com/t/assigning-constexpr-char--to-static-cha/10021357?entry=problem)
        if (strcmp(secretType, jss::secret.c_str()) == 0)
        {
            error = RPC::make_param_error(
                "The secret field is not allowed if " +
                std::string(jss::key_type) + " is used.");
            return {};
        }
    }
 
    // ripple-lib encodes seed used to generate an Ed25519 wallet in a
    // non-standard way. While we never encode seeds that way, we try
    // to detect such keys to avoid user confusion.
    // using strcmp as pointers may not match (see
    // https://developercommunity.visualstudio.com/t/assigning-constexpr-char--to-static-cha/10021357?entry=problem)
    if (strcmp(secretType, jss::seed_hex.c_str()) != 0)
    {
        seed = RPC::parseRippleLibSeed(params[secretType]);
 
        if (seed)
        {
            // If the user passed in an Ed25519 seed but *explicitly*
            // requested another key type, return an error.
            if (keyType.value_or(KeyType::ed25519) != KeyType::ed25519)
            {
                error = RPC::make_error(
                    rpcBAD_SEED, "Specified seed is for an Ed25519 wallet.");
                return {};
            }
 
            keyType = KeyType::ed25519;
        }
    }
 
    if (!keyType)
        keyType = KeyType::secp256k1;
 
    if (!seed)
    {
        if (has_key_type)
            seed = getSeedFromRPC(params, error);
        else
        {
            if (!params[jss::secret].isString())
            {
                error = RPC::expected_field_error(jss::secret, "string");
                return {};
            }
 
            seed = parseGenericSeed(params[jss::secret].asString());
        }
    }
 
    if (!seed)
    {
        if (!contains_error(error))
        {
            error = RPC::make_error(
                rpcBAD_SEED, RPC::invalid_field_message(secretType));
        }
 
        return {};
    }
 
    if (keyType != KeyType::secp256k1 && keyType != KeyType::ed25519)
        LogicError("keypairForSignature: invalid key type");
 
    return generateKeyPair(*keyType, *seed);
}
 
std::pair<RPC::Status, LedgerEntryType>
chooseLedgerEntryType(Json::Value const& params)
{
    std::pair<RPC::Status, LedgerEntryType> result{RPC::Status::OK, ltANY};
    if (params.isMember(jss::type))
    {
        static constexpr auto types = std::to_array<
            std::tuple<char const*, char const*, LedgerEntryType>>({
#pragma push_macro("LEDGER_ENTRY")
#undef LEDGER_ENTRY
 
#define LEDGER_ENTRY(tag, value, name, rpcName, ...) \
    {jss::name, jss::rpcName, tag},
 
#include <xrpl/protocol/detail/ledger_entries.macro>
 
#undef LEDGER_ENTRY
#pragma pop_macro("LEDGER_ENTRY")
        });
 
        auto const& p = params[jss::type];
        if (!p.isString())
        {
            result.first = RPC::Status{
                rpcINVALID_PARAMS, "Invalid field 'type', not string."};
            XRPL_ASSERT(
                result.first.type() == RPC::Status::Type::error_code_i,
                "ripple::RPC::chooseLedgerEntryType : first valid result type");
            return result;
        }
 
        // Use the passed in parameter to find a ledger type based on matching
        // against the canonical name (case-insensitive) or the RPC name
        // (case-sensitive).
        auto const filter = p.asString();
        auto const iter =
            std::ranges::find_if(types, [&filter](decltype(types.front())& t) {
                return boost::iequals(std::get<0>(t), filter) ||
                    std::get<1>(t) == filter;
            });
        if (iter == types.end())
        {
            result.first =
                RPC::Status{rpcINVALID_PARAMS, "Invalid field 'type'."};
            XRPL_ASSERT(
                result.first.type() == RPC::Status::Type::error_code_i,
                "ripple::RPC::chooseLedgerEntryType : second valid result "
                "type");
            return result;
        }
        result.second = std::get<2>(*iter);
    }
    return result;
}
 
bool
isAccountObjectsValidType(LedgerEntryType const& type)
{
    switch (type)
    {
        case LedgerEntryType::ltAMENDMENTS:
        case LedgerEntryType::ltDIR_NODE:
        case LedgerEntryType::ltFEE_SETTINGS:
        case LedgerEntryType::ltLEDGER_HASHES:
        case LedgerEntryType::ltNEGATIVE_UNL:
            return false;
        default:
            return true;
    }
}
 
std::variant<std::shared_ptr<Ledger const>, Json::Value>
getLedgerByContext(RPC::JsonContext& context)
{
    auto const hasHash = context.params.isMember(jss::ledger_hash);
    auto const hasIndex = context.params.isMember(jss::ledger_index);
    std::uint32_t ledgerIndex = 0;
 
    auto& ledgerMaster = context.app.getLedgerMaster();
    LedgerHash ledgerHash;
 
    if ((hasHash && hasIndex) || !(hasHash || hasIndex))
    {
        return RPC::make_param_error(
            "Exactly one of ledger_hash and ledger_index can be set.");
    }
 
    context.loadType = Resource::feeHeavyBurdenRPC;
 
    if (hasHash)
    {
        auto const& jsonHash = context.params[jss::ledger_hash];
        if (!jsonHash.isString() || !ledgerHash.parseHex(jsonHash.asString()))
            return RPC::invalid_field_error(jss::ledger_hash);
    }
    else
    {
        auto const& jsonIndex = context.params[jss::ledger_index];
        if (!jsonIndex.isInt())
            return RPC::invalid_field_error(jss::ledger_index);
 
        // We need a validated ledger to get the hash from the sequence
        if (ledgerMaster.getValidatedLedgerAge() >
            RPC::Tuning::maxValidatedLedgerAge)
        {
            if (context.apiVersion == 1)
                return rpcError(rpcNO_CURRENT);
            return rpcError(rpcNOT_SYNCED);
        }
 
        ledgerIndex = jsonIndex.asInt();
        auto ledger = ledgerMaster.getValidatedLedger();
 
        if (ledgerIndex >= ledger->info().seq)
            return RPC::make_param_error("Ledger index too large");
        if (ledgerIndex <= 0)
            return RPC::make_param_error("Ledger index too small");
 
        auto const j = context.app.journal("RPCHandler");
        // Try to get the hash of the desired ledger from the validated
        // ledger
        auto neededHash = hashOfSeq(*ledger, ledgerIndex, j);
        if (!neededHash)
        {
            // Find a ledger more likely to have the hash of the desired
            // ledger
            auto const refIndex = getCandidateLedger(ledgerIndex);
            auto refHash = hashOfSeq(*ledger, refIndex, j);
            XRPL_ASSERT(
                refHash,
                "ripple::RPC::getLedgerByContext : nonzero ledger hash");
 
            ledger = ledgerMaster.getLedgerByHash(*refHash);
            if (!ledger)
            {
                // We don't have the ledger we need to figure out which
                // ledger they want. Try to get it.
 
                if (auto il = context.app.getInboundLedgers().acquire(
                        *refHash, refIndex, InboundLedger::Reason::GENERIC))
                {
                    Json::Value jvResult = RPC::make_error(
                        rpcLGR_NOT_FOUND,
                        "acquiring ledger containing requested index");
                    jvResult[jss::acquiring] =
                        getJson(LedgerFill(*il, &context));
                    return jvResult;
                }
 
                if (auto il = context.app.getInboundLedgers().find(*refHash))
                {
                    Json::Value jvResult = RPC::make_error(
                        rpcLGR_NOT_FOUND,
                        "acquiring ledger containing requested index");
                    jvResult[jss::acquiring] = il->getJson(0);
                    return jvResult;
                }
 
                // Likely the app is shutting down
                return Json::Value();
            }
 
            neededHash = hashOfSeq(*ledger, ledgerIndex, j);
        }
        XRPL_ASSERT(
            neededHash,
            "ripple::RPC::getLedgerByContext : nonzero needed hash");
        ledgerHash = neededHash ? *neededHash : beast::zero;  // kludge
    }
 
    // Try to get the desired ledger
    // Verify all nodes even if we think we have it
    auto ledger = context.app.getInboundLedgers().acquire(
        ledgerHash, ledgerIndex, InboundLedger::Reason::GENERIC);
 
    // In standalone mode, accept the ledger from the ledger cache
    if (!ledger && context.app.config().standalone())
        ledger = ledgerMaster.getLedgerByHash(ledgerHash);
 
    if (ledger)
        return ledger;
 
    if (auto il = context.app.getInboundLedgers().find(ledgerHash))
        return il->getJson(0);
 
    return RPC::make_error(
        rpcNOT_READY, "findCreate failed to return an inbound ledger");
}
 
}  // namespace RPC
}  // namespace ripple