From bc168453dd7e90908ce62ee36f1692125e87e297 Mon Sep 17 00:00:00 2001
From: Valentin Balaschenko <13349202+vlntb@users.noreply.github.com>
Date: Wed, 15 Apr 2026 20:00:28 +0100
Subject: [PATCH] refactor: Use named constant for leaf item size (#39)

---
 src/xrpld/shamap/SHAMapTreeNode.h          |  3 +++
 src/xrpld/shamap/detail/SHAMapLeafNode.cpp |  4 ++--
 src/xrpld/shamap/detail/SHAMapTreeNode.cpp | 18 ++++++++++++++++++
 3 files changed, 23 insertions(+), 2 deletions(-)

diff --git a/src/xrpld/shamap/SHAMapTreeNode.h b/src/xrpld/shamap/SHAMapTreeNode.h
index 2c4a349019..5242e83348 100644
--- a/src/xrpld/shamap/SHAMapTreeNode.h
+++ b/src/xrpld/shamap/SHAMapTreeNode.h
@@ -41,6 +41,9 @@ static constexpr unsigned char const wireTypeInner = 2;
 static constexpr unsigned char const wireTypeCompressedInner = 3;
 static constexpr unsigned char const wireTypeTransactionWithMeta = 4;
 
+// Lower-bound sanity check for SHAMap leaf payloads.
+inline constexpr std::size_t minSHAMapItemBytes = 12;
+
 enum class SHAMapNodeType {
     tnINNER = 1,
     tnTRANSACTION_NM = 2,  // transaction, no metadata
diff --git a/src/xrpld/shamap/detail/SHAMapLeafNode.cpp b/src/xrpld/shamap/detail/SHAMapLeafNode.cpp
index 10d61ff138..169c327455 100644
--- a/src/xrpld/shamap/detail/SHAMapLeafNode.cpp
+++ b/src/xrpld/shamap/detail/SHAMapLeafNode.cpp
@@ -27,7 +27,7 @@ SHAMapLeafNode::SHAMapLeafNode(
     : SHAMapTreeNode(cowid), item_(std::move(item))
 {
     XRPL_ASSERT(
-        item_->size() >= 12,
+        item_->size() >= minSHAMapItemBytes,
         "ripple::SHAMapLeafNode::SHAMapLeafNode(boost::intrusive_ptr<"
         "SHAMapItem const>, std::uint32_t) : minimum input size");
 }
@@ -39,7 +39,7 @@ SHAMapLeafNode::SHAMapLeafNode(
     : SHAMapTreeNode(cowid, hash), item_(std::move(item))
 {
     XRPL_ASSERT(
-        item_->size() >= 12,
+        item_->size() >= minSHAMapItemBytes,
         "ripple::SHAMapLeafNode::SHAMapLeafNode(boost::intrusive_ptr<"
         "SHAMapItem const>, std::uint32_t, SHAMapHash const&) : minimum input "
         "size");
diff --git a/src/xrpld/shamap/detail/SHAMapTreeNode.cpp b/src/xrpld/shamap/detail/SHAMapTreeNode.cpp
index d1e74fd6a7..c70bddb23a 100644
--- a/src/xrpld/shamap/detail/SHAMapTreeNode.cpp
+++ b/src/xrpld/shamap/detail/SHAMapTreeNode.cpp
@@ -38,6 +38,12 @@ SHAMapTreeNode::makeTransaction(
     SHAMapHash const& hash,
     bool hashValid)
 {
+    if (data.size() < minSHAMapItemBytes)
+        Throw<std::runtime_error>(
+            "Short TXN node: " + std::to_string(data.size()) +
+            " bytes (minimum " + std::to_string(minSHAMapItemBytes) +
+            " required)");
+
     auto item =
         make_shamapitem(sha512Half(HashPrefix::transactionID, data), data);
 
@@ -68,6 +74,12 @@ SHAMapTreeNode::makeTransactionWithMeta(
 
     s.chop(tag.bytes);
 
+    if (s.size() < minSHAMapItemBytes)
+        Throw<std::runtime_error>(
+            "Short TXN+MD node: " + std::to_string(s.size()) +
+            " bytes after tag removal (minimum " +
+            std::to_string(minSHAMapItemBytes) + " required)");
+
     auto item = make_shamapitem(tag, s.slice());
 
     if (hashValid)
@@ -100,6 +112,12 @@ SHAMapTreeNode::makeAccountState(
     if (tag.isZero())
         Throw<std::runtime_error>("Invalid AS node");
 
+    if (s.size() < minSHAMapItemBytes)
+        Throw<std::runtime_error>(
+            "Short AS node: " + std::to_string(s.size()) +
+            " bytes after tag removal (minimum " +
+            std::to_string(minSHAMapItemBytes) + " required)");
+
     auto item = make_shamapitem(tag, s.slice());
 
     if (hashValid)