From 4ad94ae2ff5c3845bb308e93eb49a140f2d0cb23 Mon Sep 17 00:00:00 2001
From: Valentin Balaschenko <13349202+vlntb@users.noreply.github.com>
Date: Wed, 13 May 2026 14:53:01 +0100
Subject: [PATCH] refactor: Use named constant for leaf item size (#39) (#7130)

Co-authored-by: Ed Hennis <ed@ripple.com>
---
 include/xrpl/shamap/SHAMapTreeNode.h  |  4 +++
 src/libxrpl/shamap/SHAMapLeafNode.cpp |  4 +--
 src/libxrpl/shamap/SHAMapTreeNode.cpp | 45 ++++++++++++++++++++++++---
 3 files changed, 47 insertions(+), 6 deletions(-)

diff --git a/include/xrpl/shamap/SHAMapTreeNode.h b/include/xrpl/shamap/SHAMapTreeNode.h
index d50fc65ccb..ac48df8d46 100644
--- a/include/xrpl/shamap/SHAMapTreeNode.h
+++ b/include/xrpl/shamap/SHAMapTreeNode.h
@@ -7,6 +7,7 @@
 #include <xrpl/shamap/SHAMapItem.h>
 #include <xrpl/shamap/SHAMapNodeID.h>
 
+#include <cstddef>
 #include <cstdint>
 #include <string>
 
@@ -20,6 +21,9 @@ static constexpr unsigned char const kWIRE_TYPE_INNER = 2;
 static constexpr unsigned char const kWIRE_TYPE_COMPRESSED_INNER = 3;
 static constexpr unsigned char const kWIRE_TYPE_TRANSACTION_WITH_META = 4;
 
+// Lower bound on SHAMap leaf item payload size, in bytes.
+inline constexpr std::size_t kMIN_SHA_MAP_ITEM_BYTES = 12;
+
 enum class SHAMapNodeType {
     TnInner = 1,
     TnTransactionNm = 2,  // transaction, no metadata
diff --git a/src/libxrpl/shamap/SHAMapLeafNode.cpp b/src/libxrpl/shamap/SHAMapLeafNode.cpp
index ce41a64e56..84c4498698 100644
--- a/src/libxrpl/shamap/SHAMapLeafNode.cpp
+++ b/src/libxrpl/shamap/SHAMapLeafNode.cpp
@@ -19,7 +19,7 @@ SHAMapLeafNode::SHAMapLeafNode(boost::intrusive_ptr<SHAMapItem const> item, std:
     : SHAMapTreeNode(cowid), item_(std::move(item))
 {
     XRPL_ASSERT(
-        item_->size() >= 12,
+        item_->size() >= kMIN_SHA_MAP_ITEM_BYTES,
         "xrpl::SHAMapLeafNode::SHAMapLeafNode(boost::intrusive_ptr<"
         "SHAMapItem const>, std::uint32_t) : minimum input size");
 }
@@ -31,7 +31,7 @@ SHAMapLeafNode::SHAMapLeafNode(
     : SHAMapTreeNode(cowid, hash), item_(std::move(item))
 {
     XRPL_ASSERT(
-        item_->size() >= 12,
+        item_->size() >= kMIN_SHA_MAP_ITEM_BYTES,
         "xrpl::SHAMapLeafNode::SHAMapLeafNode(boost::intrusive_ptr<"
         "SHAMapItem const>, std::uint32_t, SHAMapHash const&) : minimum input "
         "size");
diff --git a/src/libxrpl/shamap/SHAMapTreeNode.cpp b/src/libxrpl/shamap/SHAMapTreeNode.cpp
index ac405f3286..66eced2192 100644
--- a/src/libxrpl/shamap/SHAMapTreeNode.cpp
+++ b/src/libxrpl/shamap/SHAMapTreeNode.cpp
@@ -28,6 +28,13 @@ namespace xrpl {
 intr_ptr::SharedPtr<SHAMapTreeNode>
 SHAMapTreeNode::makeTransaction(Slice data, SHAMapHash const& hash, bool hashValid)
 {
+    if (data.size() < kMIN_SHA_MAP_ITEM_BYTES)
+    {
+        Throw<std::runtime_error>(
+            "Short TXN node: " + std::to_string(data.size()) + " bytes (minimum " +
+            std::to_string(kMIN_SHA_MAP_ITEM_BYTES) + " required)");
+    }
+
     auto item = makeShamapitem(sha512Half(HashPrefix::TransactionId, data), data);
 
     if (hashValid)
@@ -44,14 +51,30 @@ SHAMapTreeNode::makeTransactionWithMeta(Slice data, SHAMapHash const& hash, bool
     uint256 tag;
 
     if (s.size() < tag.kBYTES)
-        Throw<std::runtime_error>("Short TXN+MD node");
+    {
+        Throw<std::runtime_error>(
+            "Short TXN+MD node: " + std::to_string(s.size()) + " bytes (minimum " +
+            std::to_string(tag.kBYTES) + " required for tag)");
+    }
 
     // FIXME: improve this interface so that the above check isn't needed
     if (!s.getBitString(tag, s.size() - tag.kBYTES))
-        Throw<std::out_of_range>("Short TXN+MD node (" + std::to_string(s.size()) + ")");
+    {
+        Throw<std::out_of_range>(
+            "Short TXN+MD node: failed to read tag at offset " +
+            std::to_string(s.size() - tag.kBYTES));
+    }
 
     s.chop(tag.kBYTES);
 
+    if (s.size() < kMIN_SHA_MAP_ITEM_BYTES)
+    {
+        Throw<std::runtime_error>(
+            "Short TXN+MD node: " + std::to_string(s.size()) +
+            " bytes after tag removal (minimum " + std::to_string(kMIN_SHA_MAP_ITEM_BYTES) +
+            " required)");
+    }
+
     auto item = makeShamapitem(tag, s.slice());
 
     if (hashValid)
@@ -68,17 +91,31 @@ SHAMapTreeNode::makeAccountState(Slice data, SHAMapHash const& hash, bool hashVa
     uint256 tag;
 
     if (s.size() < tag.kBYTES)
-        Throw<std::runtime_error>("short AS node");
+    {
+        Throw<std::runtime_error>(
+            "Short AS node: " + std::to_string(s.size()) + " bytes (minimum " +
+            std::to_string(tag.kBYTES) + " required for tag)");
+    }
 
     // FIXME: improve this interface so that the above check isn't needed
     if (!s.getBitString(tag, s.size() - tag.kBYTES))
-        Throw<std::out_of_range>("Short AS node (" + std::to_string(s.size()) + ")");
+    {
+        Throw<std::out_of_range>(
+            "Short AS node: failed to read tag at offset " + std::to_string(s.size() - tag.kBYTES));
+    }
 
     s.chop(tag.kBYTES);
 
     if (tag.isZero())
         Throw<std::runtime_error>("Invalid AS node");
 
+    if (s.size() < kMIN_SHA_MAP_ITEM_BYTES)
+    {
+        Throw<std::runtime_error>(
+            "Short AS node: " + std::to_string(s.size()) + " bytes after tag removal (minimum " +
+            std::to_string(kMIN_SHA_MAP_ITEM_BYTES) + " required)");
+    }
+
     auto item = makeShamapitem(tag, s.slice());
 
     if (hashValid)