From 5f6415b41d29ac8460eca1df3ed6280c5ec1a47e Mon Sep 17 00:00:00 2001
From: AdamKorcz <44787359+AdamKorcz@users.noreply.github.com>
Date: Sun, 12 May 2024 18:28:44 +0100
Subject: [PATCH] test: add fuzzer for `ClientHelloParser`

Signed-off-by: Adam Korczynski <adam@adalogics.com>
PR-URL: https://github.com/nodejs/node/pull/51088
Reviewed-By: James M Snell <jasnell@gmail.com>
---
 node.gyp                               | 43 ++++++++++++++++++++++++++
 test/fuzzers/fuzz_ClientHelloParser.cc | 16 ++++++++++
 2 files changed, 59 insertions(+)
 create mode 100644 test/fuzzers/fuzz_ClientHelloParser.cc

diff --git a/node.gyp b/node.gyp
index c7f34f5938fc9a..3e86a830b16bba 100644
--- a/node.gyp
+++ b/node.gyp
@@ -1067,6 +1067,49 @@
         }],
       ],
     }, # fuzz_env
+    { # fuzz_ClientHelloParser.cc
+      'target_name': 'fuzz_ClientHelloParser',
+      'type': 'executable',
+      'dependencies': [
+        '<(node_lib_target_name)',
+        'deps/histogram/histogram.gyp:histogram',
+        'deps/uvwasi/uvwasi.gyp:uvwasi',
+      ],
+      'includes': [
+        'node.gypi'
+      ],
+      'include_dirs': [
+        'src',
+        'tools/msvs/genfiles',
+        'deps/v8/include',
+        'deps/cares/include',
+        'deps/uv/include',
+        'deps/uvwasi/include',
+        'test/cctest',
+      ],
+      'defines': [
+        'NODE_ARCH="<(target_arch)"',
+        'NODE_PLATFORM="<(OS)"',
+        'NODE_WANT_INTERNALS=1',
+      ],
+      'sources': [
+        'src/node_snapshot_stub.cc',
+        'test/fuzzers/fuzz_ClientHelloParser.cc',
+      ],
+      'conditions': [
+        ['OS=="linux"', {
+          'ldflags': [ '-fsanitize=fuzzer' ]
+        }],
+        # Ensure that ossfuzz flag has been set and that we are on Linux
+        [ 'OS!="linux" or ossfuzz!="true"', {
+          'type': 'none',
+        }],
+        # Avoid excessive LTO
+        ['enable_lto=="true"', {
+          'ldflags': [ '-fno-lto' ],
+        }],
+      ],
+    }, # fuzz_ClientHelloParser.cc
     {
       'target_name': 'cctest',
       'type': 'executable',
diff --git a/test/fuzzers/fuzz_ClientHelloParser.cc b/test/fuzzers/fuzz_ClientHelloParser.cc
new file mode 100644
index 00000000000000..87d7ae5e303e17
--- /dev/null
+++ b/test/fuzzers/fuzz_ClientHelloParser.cc
@@ -0,0 +1,16 @@
+/*
+ * A fuzzer focused on node::crypto::ClientHelloParser.
+ */
+
+#include <stdlib.h>
+#include "crypto/crypto_clienthello-inl.h"
+
+extern "C" int LLVMFuzzerTestOneInput(const uint8_t* data, size_t size) {
+  node::crypto::ClientHelloParser parser;
+  bool end_cb_called = false;
+  parser.Start([](void* arg, auto hello) { },
+               [](void* arg) { },
+               &end_cb_called);
+  parser.Parse(data, size);
+  return 0;
+}