From e1d6fd42e9cc262e090699072be865c8f97a0be9 Mon Sep 17 00:00:00 2001
From: Volodymyr Kravets <volodymyr.kravets@outlook.com>
Date: Wed, 9 Oct 2024 11:57:43 +0300
Subject: [PATCH] perf: add overflow check

---
 .../main/java/co/rsk/core/types/bytes/BoundaryUtils.java    | 4 ++--
 .../src/main/java/co/rsk/core/types/bytes/BytesSlice.java   | 4 ++--
 .../java/co/rsk/core/types/bytes/HexPrintableBytes.java     | 6 +++---
 3 files changed, 7 insertions(+), 7 deletions(-)

diff --git a/rskj-core/src/main/java/co/rsk/core/types/bytes/BoundaryUtils.java b/rskj-core/src/main/java/co/rsk/core/types/bytes/BoundaryUtils.java
index d2ffe8a7691..d56e610b44f 100644
--- a/rskj-core/src/main/java/co/rsk/core/types/bytes/BoundaryUtils.java
+++ b/rskj-core/src/main/java/co/rsk/core/types/bytes/BoundaryUtils.java
@@ -26,10 +26,10 @@ public static void checkArraycopyParams(int srcLength, int srcPos, byte[] dest,
         if (length < 0) {
             throw new IndexOutOfBoundsException("invalid 'length': " + length);
         }
-        if (srcPos < 0 || srcPos + length > srcLength) {
+        if (srcPos < 0 || Long.sum(srcPos, length) > srcLength) {
             throw new IndexOutOfBoundsException("invalid 'srcPos' and/or 'length': [" + srcPos + ";" + length + ")");
         }
-        if (destPos < 0 || destPos + length > dest.length) {
+        if (destPos < 0 || Long.sum(destPos, length) > dest.length) {
             throw new IndexOutOfBoundsException("invalid 'destPos' and/or 'length': [" + destPos + ";" + length + ")");
         }
     }
diff --git a/rskj-core/src/main/java/co/rsk/core/types/bytes/BytesSlice.java b/rskj-core/src/main/java/co/rsk/core/types/bytes/BytesSlice.java
index 2e140f65410..82d89122753 100644
--- a/rskj-core/src/main/java/co/rsk/core/types/bytes/BytesSlice.java
+++ b/rskj-core/src/main/java/co/rsk/core/types/bytes/BytesSlice.java
@@ -104,10 +104,10 @@ default byte[] copyArrayOfRange(int from, int to) {
         if (from < 0 || from > length()) {
             throw new IndexOutOfBoundsException("invalid 'from': " + from);
         }
-        int newLength = to - from;
-        if (newLength < 0) {
+        if (to < from) {
             throw new IllegalArgumentException(from + " > " + to);
         }
+        int newLength = to - from;
         byte[] copy = new byte[newLength];
         arraycopy(from, copy, 0, Math.min(length() - from, newLength));
         return copy;
diff --git a/rskj-core/src/main/java/co/rsk/core/types/bytes/HexPrintableBytes.java b/rskj-core/src/main/java/co/rsk/core/types/bytes/HexPrintableBytes.java
index aa7e179ce6e..de8dfb1e697 100644
--- a/rskj-core/src/main/java/co/rsk/core/types/bytes/HexPrintableBytes.java
+++ b/rskj-core/src/main/java/co/rsk/core/types/bytes/HexPrintableBytes.java
@@ -86,11 +86,11 @@ default String toHexString() {
      * @return the hexadecimal representation of the bytes in the range of {@code offset} and {@code length}.
      */
     default String toHexStringV2(int offset, int length) {
-        int endIndex = offset + length;
-        if (offset < 0 || length < 0 || endIndex > length()) {
+        if (offset < 0 || length < 0 || Long.sum(offset, length) > length()) {
             throw new IndexOutOfBoundsException("invalid 'offset' and/or 'length': " + offset + "; " + length);
         }
 
+        int endIndex = offset + length;
         StringBuilder sb = new StringBuilder(length * 2);
         for (int i = offset; i < endIndex; i++) {
             byte b = byteAt(i);
@@ -106,7 +106,7 @@ class PrintableBytesHexFormatter implements PrintableBytes.Formatter<HexPrintabl
     @Override
     public String toFormattedString(@Nonnull HexPrintableBytes printableBytes, int off, int length) {
         int bytesLen = Objects.requireNonNull(printableBytes).length();
-        if (off + length > bytesLen) {
+        if (off < 0 || length < 0 || Long.sum(off, length) > bytesLen) {
             throw new IndexOutOfBoundsException("invalid 'off' and/or 'length': " + off + "; " + length);
         }