Merge branch 'develop' into mvadari/check-bounds

src/libxrpl/tx/PreflightHelpers.h

@@ -0,0 +1,66 @@
+#pragma once
+
+#include <xrpl/beast/utility/Zero.h>
+#include <xrpl/protocol/STAmount.h>
+#include <xrpl/protocol/UintTypes.h>
+
+#include <cstddef>
+
+template <class T>
+inline bool
+checkBounds(T const& value, T const& min, T const& max)
+{
+    return value >= min && value <= max;
+}
+
+template <class T>
+inline bool
+checkMax(T const& value, T const& max)
+{
+    return value <= max;
+}
+
+template <class T>
+inline bool
+checkSize(T const& value, std::size_t const max)
+{
+    return value.size() <= max;
+}
+
+template <class T>
+inline bool
+checkSizeNonEmpty(T const& value, std::size_t const max)
+{
+    return value.size() <= max && !value.empty();
+}
+
+// Checks whether a hash-like identifier field (e.g. a uint256 object ID) is
+// unset/zero.
+template <class T>
+inline bool
+isZeroId(T const& id)
+{
+    return id == beast::kZero;
+}
+
+// Checks whether an amount is a strictly positive XRP amount.
+inline bool
+isPositiveXRPAmount(xrpl::STAmount const& amount)
+{
+    return xrpl::isXRP(amount) && amount > beast::kZero;
+}
+
+// Checks whether an amount (of any asset type) is strictly positive.
+inline bool
+isPositiveAmount(xrpl::STAmount const& amount)
+{
+    return amount > beast::kZero;
+}
+
+// Checks whether a currency code is the reserved "bad"/XRP currency code,
+// i.e. not a valid IOU currency.
+inline bool
+isBadCurrency(xrpl::Currency const& currency)
+{
+    return xrpl::badCurrency() == currency;
+}

src/libxrpl/tx/transactors/escrow/EscrowCreate.cpp

@@ -28,11 +28,12 @@
 #include <xrpl/protocol/STLedgerEntry.h>
 #include <xrpl/protocol/STTx.h>
 #include <xrpl/protocol/TER.h>
-#include <xrpl/protocol/UintTypes.h>
 #include <xrpl/protocol/XRPAmount.h>
 #include <xrpl/tx/Transactor.h>
 #include <xrpl/tx/applySteps.h>
 
+#include <libxrpl/tx/PreflightHelpers.h>
+
 #include <memory>
 #include <system_error>
 #include <variant>
@@ -101,10 +102,10 @@ NotTEC
 escrowCreatePreflightHelper<Issue>(PreflightContext const& ctx)
 {
     STAmount const amount = ctx.tx[sfAmount];
-    if (amount.native() || amount <= beast::kZero)
+    if (amount.native() || !isPositiveAmount(amount))
         return temBAD_AMOUNT;
 
-    if (badCurrency() == amount.get<Issue>().currency)
+    if (isBadCurrency(amount.get<Issue>().currency))
         return temBAD_CURRENCY;
 
     return tesSUCCESS;
@@ -118,7 +119,7 @@ escrowCreatePreflightHelper<MPTIssue>(PreflightContext const& ctx)
         return temDISABLED;
 
     auto const amount = ctx.tx[sfAmount];
-    if (amount.native() || amount.mpt() > MPTAmount{kMaxMpTokenAmount} || amount <= beast::kZero)
+    if (amount.native() || amount.mpt() > MPTAmount{kMaxMpTokenAmount} || !isPositiveAmount(amount))
         return temBAD_AMOUNT;
 
     return tesSUCCESS;
@@ -141,7 +142,7 @@ EscrowCreate::preflight(PreflightContext const& ctx)
     }
     else
     {
-        if (amount <= beast::kZero)
+        if (!isPositiveXRPAmount(amount))
             return temBAD_AMOUNT;
     }
 

src/libxrpl/tx/transactors/lending/LoanBrokerCoverClawback.cpp

@@ -27,6 +27,8 @@
 #include <xrpl/protocol/XRPAmount.h>
 #include <xrpl/tx/Transactor.h>
 
+#include <libxrpl/tx/PreflightHelpers.h>
+
 #include <expected>
 #include <optional>
 #include <variant>
@@ -48,7 +50,7 @@ LoanBrokerCoverClawback::preflight(PreflightContext const& ctx)
     if (!brokerID && !amount)
         return temINVALID;
 
-    if (brokerID && *brokerID == beast::kZero)
+    if (brokerID && isZeroId(*brokerID))
         return temINVALID;
 
     if (amount)

src/libxrpl/tx/transactors/lending/LoanBrokerCoverDeposit.cpp

@@ -16,6 +16,8 @@
 #include <xrpl/protocol/XRPAmount.h>
 #include <xrpl/tx/Transactor.h>
 
+#include <libxrpl/tx/PreflightHelpers.h>
+
 namespace xrpl {
 
 bool
@@ -27,11 +29,11 @@ LoanBrokerCoverDeposit::checkExtraFeatures(PreflightContext const& ctx)
 NotTEC
 LoanBrokerCoverDeposit::preflight(PreflightContext const& ctx)
 {
-    if (ctx.tx[sfLoanBrokerID] == beast::kZero)
+    if (isZeroId(ctx.tx[sfLoanBrokerID]))
         return temINVALID;
 
     auto const dstAmount = ctx.tx[sfAmount];
-    if (dstAmount <= beast::kZero)
+    if (!isPositiveAmount(dstAmount))
         return temBAD_AMOUNT;
 
     if (!isLegalNet(dstAmount))

src/libxrpl/tx/transactors/lending/LoanBrokerCoverWithdraw.cpp

@@ -2,7 +2,6 @@
 
 #include <xrpl/basics/Log.h>
 #include <xrpl/basics/Number.h>
-#include <xrpl/beast/utility/Zero.h>
 #include <xrpl/ledger/View.h>
 #include <xrpl/ledger/helpers/AccountRootHelpers.h>
 #include <xrpl/ledger/helpers/LendingHelpers.h>
@@ -20,6 +19,8 @@
 #include <xrpl/protocol/XRPAmount.h>
 #include <xrpl/tx/Transactor.h>
 
+#include <libxrpl/tx/PreflightHelpers.h>
+
 namespace xrpl {
 
 bool
@@ -31,11 +32,11 @@ LoanBrokerCoverWithdraw::checkExtraFeatures(PreflightContext const& ctx)
 NotTEC
 LoanBrokerCoverWithdraw::preflight(PreflightContext const& ctx)
 {
-    if (ctx.tx[sfLoanBrokerID] == beast::kZero)
+    if (isZeroId(ctx.tx[sfLoanBrokerID]))
         return temINVALID;
 
     auto const dstAmount = ctx.tx[sfAmount];
-    if (dstAmount <= beast::kZero)
+    if (!isPositiveAmount(dstAmount))
         return temBAD_AMOUNT;
 
     if (!isLegalNet(dstAmount))
@@ -43,7 +44,7 @@ LoanBrokerCoverWithdraw::preflight(PreflightContext const& ctx)
 
     if (auto const destination = ctx.tx[~sfDestination])
     {
-        if (*destination == beast::kZero)
+        if (isZeroId(*destination))
         {
             return temMALFORMED;
         }

src/libxrpl/tx/transactors/lending/LoanBrokerDelete.cpp

@@ -18,6 +18,8 @@
 #include <xrpl/protocol/XRPAmount.h>
 #include <xrpl/tx/Transactor.h>
 
+#include <libxrpl/tx/PreflightHelpers.h>
+
 namespace xrpl {
 
 bool
@@ -29,7 +31,7 @@ LoanBrokerDelete::checkExtraFeatures(PreflightContext const& ctx)
 NotTEC
 LoanBrokerDelete::preflight(PreflightContext const& ctx)
 {
-    if (ctx.tx[sfLoanBrokerID] == beast::kZero)
+    if (isZeroId(ctx.tx[sfLoanBrokerID]))
         return temINVALID;
 
     return tesSUCCESS;

src/libxrpl/tx/transactors/lending/LoanBrokerSet.cpp

@@ -2,7 +2,6 @@
 
 #include <xrpl/basics/Log.h>
 #include <xrpl/basics/Number.h>
-#include <xrpl/beast/utility/Zero.h>
 #include <xrpl/core/ServiceRegistry.h>
 #include <xrpl/ledger/View.h>
 #include <xrpl/ledger/helpers/AccountRootHelpers.h>
@@ -20,6 +19,8 @@
 #include <xrpl/protocol/XRPAmount.h>
 #include <xrpl/tx/Transactor.h>
 
+#include <libxrpl/tx/PreflightHelpers.h>
+
 #include <memory>
 #include <vector>
 
@@ -57,13 +58,13 @@ LoanBrokerSet::preflight(PreflightContext const& ctx)
             tx.isFieldPresent(sfCoverRateLiquidation))
             return temINVALID;
 
-        if (tx[sfLoanBrokerID] == beast::kZero)
+        if (isZeroId(tx[sfLoanBrokerID]))
             return temINVALID;
     }
 
     if (auto const vaultID = tx.at(~sfVaultID))
     {
-        if (*vaultID == beast::kZero)
+        if (isZeroId(*vaultID))
             return temINVALID;
     }
 

src/libxrpl/tx/transactors/lending/LoanDelete.cpp

@@ -16,6 +16,8 @@
 #include <xrpl/protocol/XRPAmount.h>
 #include <xrpl/tx/Transactor.h>
 
+#include <libxrpl/tx/PreflightHelpers.h>
+
 namespace xrpl {
 
 bool
@@ -27,7 +29,7 @@ LoanDelete::checkExtraFeatures(PreflightContext const& ctx)
 NotTEC
 LoanDelete::preflight(PreflightContext const& ctx)
 {
-    if (ctx.tx[sfLoanID] == beast::kZero)
+    if (isZeroId(ctx.tx[sfLoanID]))
         return temINVALID;
 
     return tesSUCCESS;

src/libxrpl/tx/transactors/lending/LoanManage.cpp

@@ -2,7 +2,6 @@
 
 #include <xrpl/basics/Log.h>
 #include <xrpl/basics/Number.h>
-#include <xrpl/beast/utility/Zero.h>
 #include <xrpl/core/ServiceRegistry.h>
 #include <xrpl/ledger/ApplyView.h>
 #include <xrpl/ledger/View.h>
@@ -24,6 +23,8 @@
 #include <xrpl/protocol/XRPAmount.h>
 #include <xrpl/tx/Transactor.h>
 
+#include <libxrpl/tx/PreflightHelpers.h>
+
 #include <algorithm>
 #include <cstdint>
 namespace xrpl {
@@ -43,7 +44,7 @@ LoanManage::getFlagsMask(PreflightContext const& ctx)
 NotTEC
 LoanManage::preflight(PreflightContext const& ctx)
 {
-    if (ctx.tx[sfLoanID] == beast::kZero)
+    if (isZeroId(ctx.tx[sfLoanID]))
         return temINVALID;
 
     // Flags are mutually exclusive

src/libxrpl/tx/transactors/lending/LoanPay.cpp

@@ -25,6 +25,8 @@
 #include <xrpl/tx/Transactor.h>
 #include <xrpl/tx/transactors/lending/LoanManage.h>
 
+#include <libxrpl/tx/PreflightHelpers.h>
+
 #include <algorithm>
 #include <bit>
 #include <cstdint>
@@ -48,10 +50,10 @@ LoanPay::getFlagsMask(PreflightContext const& ctx)
 NotTEC
 LoanPay::preflight(PreflightContext const& ctx)
 {
-    if (ctx.tx[sfLoanID] == beast::kZero)
+    if (isZeroId(ctx.tx[sfLoanID]))
         return temINVALID;
 
-    if (ctx.tx[sfAmount] <= beast::kZero)
+    if (!isPositiveAmount(ctx.tx[sfAmount]))
         return temBAD_AMOUNT;
 
     // The loan payment flags are all mutually exclusive. If more than one is

src/libxrpl/tx/transactors/lending/LoanSet.cpp

@@ -28,6 +28,8 @@
 #include <xrpl/protocol/XRPAmount.h>
 #include <xrpl/tx/Transactor.h>
 
+#include <libxrpl/tx/PreflightHelpers.h>
+
 #include <cstddef>
 #include <cstdint>
 #include <limits>
@@ -138,7 +140,7 @@ LoanSet::preflight(PreflightContext const& ctx)
             return *ret;
     }
 
-    if (auto const brokerID = ctx.tx[~sfLoanBrokerID]; brokerID && *brokerID == beast::kZero)
+    if (auto const brokerID = ctx.tx[~sfLoanBrokerID]; brokerID && isZeroId(*brokerID))
         return temINVALID;
 
     return tesSUCCESS;

src/libxrpl/tx/transactors/payment/Payment.cpp

@@ -36,6 +36,8 @@
 #include <xrpl/tx/applySteps.h>
 #include <xrpl/tx/paths/RippleCalc.h>
 
+#include <libxrpl/tx/PreflightHelpers.h>
+
 #include <algorithm>
 #include <cstdint>
 #include <limits>
@@ -143,7 +145,7 @@ Payment::preflight(PreflightContext const& ctx)
     // A zero DomainID is invalid for a PermissionedDomain ledger entry because
     // keylet::permissionedDomain(uint256) uses the DomainID as the ledger key.
     if (auto const domainID = tx[~sfDomainID];
-        ctx.rules.enabled(fixCleanup3_2_0) && domainID && *domainID == beast::kZero)
+        ctx.rules.enabled(fixCleanup3_2_0) && domainID && isZeroId(*domainID))
         return temMALFORMED;
 
     bool const partialPaymentAllowed = tx.isFlag(tfPartialPayment);
@@ -183,13 +185,13 @@ Payment::preflight(PreflightContext const& ctx)
                         << "Payment destination account not specified.";
         return temDST_NEEDED;
     }
-    if (hasMax && maxSourceAmount <= beast::kZero)
+    if (hasMax && !isPositiveAmount(maxSourceAmount))
     {
         JLOG(j.trace()) << "Malformed transaction: bad max amount: "
                         << maxSourceAmount.getFullText();
         return temBAD_AMOUNT;
     }
-    if (dstAmount <= beast::kZero)
+    if (!isPositiveAmount(dstAmount))
     {
         JLOG(j.trace()) << "Malformed transaction: bad dst amount: " << dstAmount.getFullText();
         return temBAD_AMOUNT;

src/libxrpl/tx/transactors/payment_channel/PaymentChannelClaim.cpp

@@ -22,6 +22,8 @@
 #include <xrpl/protocol/XRPAmount.h>
 #include <xrpl/tx/Transactor.h>
 
+#include <libxrpl/tx/PreflightHelpers.h>
+
 #include <cstdint>
 #include <optional>
 
@@ -42,15 +44,15 @@ PaymentChannelClaim::getFlagsMask(PreflightContext const&)
 NotTEC
 PaymentChannelClaim::preflight(PreflightContext const& ctx)
 {
-    if (ctx.rules.enabled(fixCleanup3_2_0) && ctx.tx[sfChannel] == beast::kZero)
+    if (ctx.rules.enabled(fixCleanup3_2_0) && isZeroId(ctx.tx[sfChannel]))
         return temMALFORMED;
 
     auto const bal = ctx.tx[~sfBalance];
-    if (bal && (!isXRP(*bal) || *bal <= beast::kZero))
+    if (bal && !isPositiveXRPAmount(*bal))
         return temBAD_AMOUNT;
 
     auto const amt = ctx.tx[~sfAmount];
-    if (amt && (!isXRP(*amt) || *amt <= beast::kZero))
+    if (amt && !isPositiveXRPAmount(*amt))
         return temBAD_AMOUNT;
 
     if (bal && amt && *bal > *amt)

src/libxrpl/tx/transactors/payment_channel/PaymentChannelCreate.cpp

@@ -1,7 +1,6 @@
 #include <xrpl/tx/transactors/payment_channel/PaymentChannelCreate.h>
 
 #include <xrpl/basics/chrono.h>
-#include <xrpl/beast/utility/Zero.h>
 #include <xrpl/core/ServiceRegistry.h>
 #include <xrpl/ledger/ApplyView.h>
 #include <xrpl/ledger/View.h>
@@ -22,6 +21,8 @@
 #include <xrpl/tx/Transactor.h>
 #include <xrpl/tx/applySteps.h>
 
+#include <libxrpl/tx/PreflightHelpers.h>
+
 #include <memory>
 
 namespace xrpl {
@@ -57,7 +58,7 @@ PaymentChannelCreate::makeTxConsequences(PreflightContext const& ctx)
 NotTEC
 PaymentChannelCreate::preflight(PreflightContext const& ctx)
 {
-    if (!isXRP(ctx.tx[sfAmount]) || (ctx.tx[sfAmount] <= beast::kZero))
+    if (!isPositiveXRPAmount(ctx.tx[sfAmount]))
         return temBAD_AMOUNT;
 
     if (ctx.tx[sfAccount] == ctx.tx[sfDestination])

src/libxrpl/tx/transactors/payment_channel/PaymentChannelFund.cpp

@@ -1,7 +1,6 @@
 #include <xrpl/tx/transactors/payment_channel/PaymentChannelFund.h>
 
 #include <xrpl/beast/utility/Journal.h>
-#include <xrpl/beast/utility/Zero.h>
 #include <xrpl/ledger/ApplyView.h>
 #include <xrpl/ledger/ReadView.h>
 #include <xrpl/ledger/helpers/AccountRootHelpers.h>
@@ -20,6 +19,8 @@
 #include <xrpl/tx/Transactor.h>
 #include <xrpl/tx/applySteps.h>
 
+#include <libxrpl/tx/PreflightHelpers.h>
+
 namespace xrpl {
 
 TxConsequences
@@ -31,10 +32,10 @@ PaymentChannelFund::makeTxConsequences(PreflightContext const& ctx)
 NotTEC
 PaymentChannelFund::preflight(PreflightContext const& ctx)
 {
-    if (ctx.rules.enabled(fixCleanup3_2_0) && ctx.tx[sfChannel] == beast::kZero)
+    if (ctx.rules.enabled(fixCleanup3_2_0) && isZeroId(ctx.tx[sfChannel]))
         return temMALFORMED;
 
-    if (!isXRP(ctx.tx[sfAmount]) || (ctx.tx[sfAmount] <= beast::kZero))
+    if (!isPositiveXRPAmount(ctx.tx[sfAmount]))
         return temBAD_AMOUNT;
 
     return tesSUCCESS;

src/libxrpl/tx/transactors/permissioned_domain/PermissionedDomainDelete.cpp

@@ -1,7 +1,6 @@
 #include <xrpl/tx/transactors/permissioned_domain/PermissionedDomainDelete.h>
 
 #include <xrpl/basics/Log.h>
-#include <xrpl/beast/utility/Zero.h>
 #include <xrpl/beast/utility/instrumentation.h>
 #include <xrpl/ledger/helpers/AccountRootHelpers.h>
 #include <xrpl/protocol/Indexes.h>
@@ -12,13 +11,15 @@
 #include <xrpl/protocol/XRPAmount.h>
 #include <xrpl/tx/Transactor.h>
 
+#include <libxrpl/tx/PreflightHelpers.h>
+
 namespace xrpl {
 
 NotTEC
 PermissionedDomainDelete::preflight(PreflightContext const& ctx)
 {
     auto const domain = ctx.tx.getFieldH256(sfDomainID);
-    if (domain == beast::kZero)
+    if (isZeroId(domain))
         return temMALFORMED;
 
     return tesSUCCESS;

src/libxrpl/tx/transactors/permissioned_domain/PermissionedDomainSet.cpp

@@ -1,6 +1,5 @@
 #include <xrpl/tx/transactors/permissioned_domain/PermissionedDomainSet.h>
 
-#include <xrpl/beast/utility/Zero.h>
 #include <xrpl/core/ServiceRegistry.h>
 #include <xrpl/ledger/helpers/AccountRootHelpers.h>
 #include <xrpl/ledger/helpers/CredentialHelpers.h>
@@ -17,6 +16,8 @@
 #include <xrpl/protocol/XRPAmount.h>
 #include <xrpl/tx/Transactor.h>
 
+#include <libxrpl/tx/PreflightHelpers.h>
+
 #include <memory>
 #include <utility>
 
@@ -39,7 +40,7 @@ PermissionedDomainSet::preflight(PreflightContext const& ctx)
         return err;
 
     auto const domain = ctx.tx.at(~sfDomainID);
-    if (domain && *domain == beast::kZero)
+    if (domain && isZeroId(*domain))
         return temMALFORMED;
 
     return tesSUCCESS;

src/libxrpl/tx/transactors/token/Clawback.cpp

@@ -22,6 +22,8 @@
 #include <xrpl/tx/ApplyContext.h>
 #include <xrpl/tx/Transactor.h>
 
+#include <libxrpl/tx/PreflightHelpers.h>
+
 #include <algorithm>
 #include <variant>
 
@@ -44,7 +46,7 @@ preflightHelper<Issue>(PreflightContext const& ctx)
     // The issuer field is used for the token holder instead
     AccountID const& holder = clawAmount.getIssuer();
 
-    if (issuer == holder || isXRP(clawAmount) || clawAmount <= beast::kZero)
+    if (issuer == holder || isXRP(clawAmount) || !isPositiveAmount(clawAmount))
         return temBAD_AMOUNT;
 
     return tesSUCCESS;
@@ -67,7 +69,7 @@ preflightHelper<MPTIssue>(PreflightContext const& ctx)
     if (ctx.tx[sfAccount] == *mptHolder)
         return temMALFORMED;
 
-    if (clawAmount.mpt() > MPTAmount{kMaxMpTokenAmount} || clawAmount <= beast::kZero)
+    if (clawAmount.mpt() > MPTAmount{kMaxMpTokenAmount} || !isPositiveAmount(clawAmount))
         return temBAD_AMOUNT;
 
     return tesSUCCESS;

src/libxrpl/tx/transactors/token/MPTokenIssuanceCreate.cpp

@@ -1,7 +1,6 @@
 #include <xrpl/tx/transactors/token/MPTokenIssuanceCreate.h>
 
 #include <xrpl/beast/utility/Journal.h>
-#include <xrpl/beast/utility/Zero.h>
 #include <xrpl/core/ServiceRegistry.h>
 #include <xrpl/ledger/ApplyView.h>
 #include <xrpl/ledger/ReadView.h>
@@ -21,6 +20,8 @@
 #include <xrpl/protocol/XRPAmount.h>
 #include <xrpl/tx/Transactor.h>
 
+#include <libxrpl/tx/PreflightHelpers.h>
+
 #include <cstdint>
 #include <expected>
 #include <memory>
@@ -87,7 +88,7 @@ MPTokenIssuanceCreate::preflight(PreflightContext const& ctx)
 
     if (auto const domain = ctx.tx[~sfDomainID])
     {
-        if (*domain == beast::kZero)
+        if (isZeroId(*domain))
             return temMALFORMED;
 
         // Domain present implies that MPTokenIssuance is not public

src/libxrpl/tx/transactors/token/TrustSet.cpp

@@ -25,6 +25,8 @@
 #include <xrpl/protocol/XRPAmount.h>
 #include <xrpl/tx/Transactor.h>
 
+#include <libxrpl/tx/PreflightHelpers.h>
+
 #include <cstdint>
 #include <unordered_set>
 
@@ -98,7 +100,7 @@ TrustSet::preflight(PreflightContext const& ctx)
         return temBAD_LIMIT;
     }
 
-    if (badCurrency() == saLimitAmount.get<Issue>().currency)
+    if (isBadCurrency(saLimitAmount.get<Issue>().currency))
     {
         JLOG(j.trace()) << "Malformed transaction: specifies XRP as IOU";
         return temBAD_CURRENCY;

src/libxrpl/tx/transactors/vault/VaultDelete.cpp

@@ -2,7 +2,6 @@
 
 #include <xrpl/basics/Log.h>
 #include <xrpl/basics/base_uint.h>
-#include <xrpl/beast/utility/Zero.h>
 #include <xrpl/ledger/helpers/AccountRootHelpers.h>
 #include <xrpl/ledger/helpers/MPTokenHelpers.h>
 #include <xrpl/ledger/helpers/TokenHelpers.h>
@@ -19,12 +18,14 @@
 #include <xrpl/protocol/XRPAmount.h>
 #include <xrpl/tx/Transactor.h>
 
+#include <libxrpl/tx/PreflightHelpers.h>
+
 namespace xrpl {
 
 NotTEC
 VaultDelete::preflight(PreflightContext const& ctx)
 {
-    if (ctx.tx[sfVaultID] == beast::kZero)
+    if (isZeroId(ctx.tx[sfVaultID]))
     {
         JLOG(ctx.j.debug()) << "VaultDelete: zero/empty vault ID.";
         return temMALFORMED;

src/libxrpl/tx/transactors/vault/VaultWithdraw.cpp

@@ -23,6 +23,8 @@
 #include <xrpl/protocol/XRPAmount.h>
 #include <xrpl/tx/Transactor.h>
 
+#include <libxrpl/tx/PreflightHelpers.h>
+
 #include <stdexcept>
 
 namespace xrpl {
@@ -42,18 +44,18 @@ shouldWaiveWithdrawal(ReadView const& view, AccountID const& account, SLE::const
 NotTEC
 VaultWithdraw::preflight(PreflightContext const& ctx)
 {
-    if (ctx.tx[sfVaultID] == beast::kZero)
+    if (isZeroId(ctx.tx[sfVaultID]))
     {
         JLOG(ctx.j.debug()) << "VaultWithdraw: zero/empty vault ID.";
         return temMALFORMED;
     }
 
-    if (ctx.tx[sfAmount] <= beast::kZero)
+    if (!isPositiveAmount(ctx.tx[sfAmount]))
         return temBAD_AMOUNT;
 
     if (auto const destination = ctx.tx[~sfDestination])
     {
-        if (*destination == beast::kZero)
+        if (isZeroId(*destination))
         {
             return temMALFORMED;
         }