Simple fuzzer for nlohmann/json library (#27)

json/Dockerfile

@@ -0,0 +1,21 @@
+# Copyright 2016 Google Inc.
+#
+# 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.
+#
+################################################################################
+
+FROM ossfuzz/base-libfuzzer
+MAINTAINER vitalybuka@gmail.com
+RUN apt-get install -y binutils gcc
+
+COPY build.sh /src/

json/Jenkinsfile

@@ -0,0 +1,22 @@
+// Copyright 2016 Google Inc.
+//
+// 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.
+//
+////////////////////////////////////////////////////////////////////////////////
+
+def libfuzzerBuild = fileLoader.fromGit('infra/libfuzzer-pipeline.groovy',
+                                        'https://github.com/google/oss-fuzz.git')
+
+libfuzzerBuild {
+  git = "https://github.com/nlohmann/json.git"
+}

json/build.sh

@@ -0,0 +1,22 @@
+#!/bin/bash -eu
+# Copyright 2016 Google Inc.
+#
+# 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.
+#
+################################################################################
+
+cd /src/json
+
+$CXX $CXXFLAGS -std=c++11 -I/src/json/src/ \
+    /src/oss-fuzz/json/parse_fuzzer.cc -o /out/parse_fuzzer \
+    /work/libfuzzer/*.o $LDFLAGS

json/json.options

@@ -0,0 +1,3 @@
+[libfuzzer]
+max_len = 456
+timeout = 10

json/parse_fuzzer.cc

@@ -0,0 +1,36 @@
+// Copyright 2016 Google Inc.
+//
+// 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 <iostream>
+#include <sstream>
+#include <json.hpp>
+
+using json = nlohmann::json;
+
+extern "C" int LLVMFuzzerTestOneInput(const uint8_t* data, size_t size) {
+  try {
+    std::stringstream s;
+    s << json::parse(data, data + size);
+    try {
+      auto j = json::parse(s.str());
+      std::stringstream s2;
+      s2 << j;
+      assert(s.str() == s2.str());
+      assert(j == json::parse(s.str()));
+    } catch (const std::invalid_argument&) { 
+      assert(0);
+    }
+  } catch (const std::invalid_argument&) { }
+  return 0;
+}

scripts/helper.py

@@ -202,7 +202,7 @@ def build_fuzzers(build_args):
 
 def run_fuzzer(run_args):
   """Runs a fuzzer in the container."""
-  parser = argparse.ArgumentParser('helper.py build_fuzzers')
+  parser = argparse.ArgumentParser('helper.py run_fuzzer')
   parser.add_argument('library_name', help='name of the library')
   parser.add_argument('fuzzer_name', help='name of the fuzzer')
   parser.add_argument('fuzzer_args', help='arguments to pass to the fuzzer',