From 3ca969ce858fe9b81813c5cab51838e7a3dd3e7d Mon Sep 17 00:00:00 2001
From: dmiller <dmiller@e0a8ed71-7df4-0310-8962-fdc924857419>
Date: Fri, 21 Aug 2026 01:14:27 +0000
Subject: [PATCH] Fuzzer for various hex-related utility functions

---
 fuzz/.gitignore       |  2 ++
 fuzz/fuzz_hexutils.cc | 31 +++++++++++++++++++++++++++++++
 2 files changed, 33 insertions(+)
 create mode 100644 fuzz/fuzz_hexutils.cc

diff --git a/fuzz/.gitignore b/fuzz/.gitignore
index 2a310568d..38fe14e5c 100644
--- a/fuzz/.gitignore
+++ b/fuzz/.gitignore
@@ -3,4 +3,6 @@ fuzz_dns_packet_parseFromBuffer
 fuzz_ippackethdrinfo
 fuzz_traceroute_decode_reply
 fuzz_gettcpopt_ts
+fuzz_validatepkt
+fuzz_hexutils
 corpus/
diff --git a/fuzz/fuzz_hexutils.cc b/fuzz/fuzz_hexutils.cc
new file mode 100644
index 000000000..b68f569cb
--- /dev/null
+++ b/fuzz/fuzz_hexutils.cc
@@ -0,0 +1,31 @@
+#include "common.h"
+#include "../output.h"
+#include "../utils.h"
+
+#include <stddef.h>
+#include <stdint.h>
+
+extern "C"
+int LLVMFuzzerTestOneInput(const uint8_t *data, size_t size)
+{
+  fuzz_init();
+  unsigned int newlen = 0;
+  char *cbuf = new char[size + 1];
+  memcpy(cbuf, data, size);
+  cbuf[size] = '\0';
+  char *cdata = cstring_unescape(cbuf, &newlen);
+  int bufsize = newlen * 4 + newlen / 8 + 1;
+  char *buf = new char[bufsize];
+
+  bintohexstr(buf, bufsize, cdata, (int)newlen);
+  size_t phs_len = 0;
+  u8 *phs_buf = parse_hex_string(buf, &phs_len);
+  if (phs_buf != NULL) {
+    volatile std::string safe = protect_xml(std::string((char *)phs_buf, phs_len));
+    (void) safe;
+  }
+
+  delete[] buf;
+  delete[] cbuf;
+  return 0;
+}