libevent: extend with a http fuzzer

Signed-off-by: David Korczynski <[email protected]>

projects/libevent/http_fuzzer.cc

@@ -0,0 +1,78 @@
+/* Copyright 2023 Google LLC
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+      http://www.apache.org/licenses/LICENSE-2.0
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+#include <stddef.h>
+#include <stdint.h>
+#include <stdlib.h>
+#include <string>
+#include <sys/socket.h>
+
+#include <fuzzer/FuzzedDataProvider.h>
+
+extern "C" {
+#include "libevent/include/event2/event.h"
+#include "libevent/include/event2/buffer.h"
+#include "libevent/include/event2/buffer_compat.h"
+#include "libevent/include/event2/util.h"
+#include "libevent/include/event2/event.h"
+#include "libevent/include/event2/http.h"
+#include "libevent/include/event2/http_struct.h"
+#include "libevent/include/event2/buffer.h"
+#include "libevent/include/event2/bufferevent.h"
+#include "libevent/http-internal.h"
+}
+
+extern "C" int LLVMFuzzerTestOneInput(const uint8_t *data, size_t size) {
+  if (size < 1) {
+    return 0;
+  }
+  // Prepare in case it's used.
+  struct evhttp_connection evcon;
+  evcon.ext_method_cmp = NULL;
+  evcon.http_server = NULL;
+
+  // Decider to determine which request type to parse.
+  uint8_t decider = data[0];
+  data++;
+  size--;
+
+  FuzzedDataProvider data_provider(data, size);
+  std::string s1 = data_provider.ConsumeRandomLengthString();
+  struct evbuffer *buf = evbuffer_new();
+  evbuffer_add(buf, s1.c_str(), s1.size());
+
+  struct evhttp_request *req = evhttp_request_new(NULL, NULL);
+
+  // Use either the defailt request type or EVHTTP_REQUEST
+  if (decider % 2 == 1) {
+    req->kind=EVHTTP_REQUEST;
+    req->evcon = &evcon;
+  }
+
+  enum message_read_status data_read;
+
+  data_read = evhttp_parse_firstline_(req, buf);
+  if (data_read != ALL_DATA_READ) {
+    data_read = evhttp_parse_headers_(req, buf);
+    if (data_read != ALL_DATA_READ) {
+      data_read = evhttp_parse_headers_(req, buf);
+      if (data_read != ALL_DATA_READ) {
+        evhttp_request_get_input_headers(req);
+      }
+    }
+  }
+
+  // Cleanup
+  evhttp_request_free(req);
+  evbuffer_free(buf);
+  return 0;
+}