Add cpp-httplib to oss-fuzz (#684)

* *Add server fuzzer target  and seed corpus
* Add fuzz_test option to Makefile

* Fix #685

* Try to fix Github actions on Ubuntu

* Added ReadTimeoutSSL test

* Comment out `-fsanitize=address`

* Rebase upstream changes

* remove address sanitizer temporarily

* Add separate Makefile for fuzzing

* 1. Remove special char from dictionary
2. Clean fuzzing/Makefile

* Use specific path to avoid accidently linking openssl version brought in by oss-fuzz

* remove addition of flags

* Refactor Makefile

* Add missing newline

* Add fuzztest to github workflow

* Fix

Co-authored-by: yhirose <[email protected]>

Author: omjego

.github/workflows/test.yaml

@@ -27,6 +27,9 @@ jobs:
     - name: make
       if: matrix.os != 'windows-latest'
       run: cd test && make
+    - name: check fuzz test target
+      if: matrix.os == 'ubuntu-latest'
+      run: cd test && make -f Makefile.fuzz_test
     - name: setup msbuild on windows
       if: matrix.os == 'windows-latest'
       uses: warrenbuckley/Setup-MSBuild@v1

test/Makefile

@@ -1,4 +1,3 @@
-
 #CXX = clang++
 CXXFLAGS = -ggdb -O0 -std=c++11 -DGTEST_USE_OWN_TR1_TUPLE -I.. -I. -Wall -Wextra -Wtype-limits -Wconversion #-fsanitize=address
 

test/Makefile.fuzz_test

@@ -0,0 +1,36 @@
+
+#CXX = clang++
+CXXFLAGS += -ggdb -O0 -std=c++11 -DGTEST_USE_OWN_TR1_TUPLE -I.. -I. -Wall -Wextra -Wtype-limits -Wconversion
+
+OPENSSL_DIR = /usr/local/opt/[email protected]
+OPENSSL_SUPPORT = -DCPPHTTPLIB_OPENSSL_SUPPORT -I$(OPENSSL_DIR)/include -L$(OPENSSL_DIR)/lib -lssl -lcrypto
+
+ZLIB_SUPPORT = -DCPPHTTPLIB_ZLIB_SUPPORT -lz
+
+BROTLI_DIR = /usr/local/opt/brotli
+BROTLI_SUPPORT = -DCPPHTTPLIB_BROTLI_SUPPORT -I$(BROTLI_DIR)/include -L$(BROTLI_DIR)/lib -lbrotlicommon -lbrotlienc -lbrotlidec
+
+# By default, use standalone_fuzz_target_runner.
+# This runner does no fuzzing, but simply executes the inputs
+# provided via parameters.
+# Run e.g. "make all LIB_FUZZING_ENGINE=/path/to/libFuzzer.a"
+# to link the fuzzer(s) against a real fuzzing engine.
+# OSS-Fuzz will define its own value for LIB_FUZZING_ENGINE.
+LIB_FUZZING_ENGINE ?= standalone_fuzz_target_runner.o
+
+# Runs server_fuzzer.cc based on value of $(LIB_FUZZING_ENGINE).
+# Usage: make fuzz_test LIB_FUZZING_ENGINE=/path/to/libFuzzer
+all fuzz_test: server_fuzzer
+	./server_fuzzer fuzzing/corpus/*
+
+# Fuzz target, so that you can choose which $(LIB_FUZZING_ENGINE) to use.
+server_fuzzer : fuzzing/server_fuzzer.cc ../httplib.h standalone_fuzz_target_runner.o
+	$(CXX) $(CXXFLAGS) -o $@  $< $(OPENSSL_SUPPORT)  $(ZLIB_SUPPORT) $(BROTLI_SUPPORT) $(LIB_FUZZING_ENGINE) -pthread
+
+# Standalone fuzz runner, which just reads inputs from fuzzing/corpus/ dir and
+# feeds it to server_fuzzer.
+standalone_fuzz_target_runner.o : fuzzing/standalone_fuzz_target_runner.cpp
+	$(CXX) $(CXXFLAGS) -c -o $@ $<
+
+clean:
+	rm -f server_fuzzer pem *.0 *.o *.1 *.srl *.zip

test/fuzzing/Makefile

@@ -0,0 +1,26 @@
+
+#CXX = clang++
+# Do not add default sanitizer flags here as OSS-fuzz adds its own sanitizer flags.
+CXXFLAGS += -ggdb -O0 -std=c++11 -DGTEST_USE_OWN_TR1_TUPLE -I../.. -I. -Wall -Wextra -Wtype-limits -Wconversion
+
+OPENSSL_DIR = /usr/local/opt/[email protected]
+
+# Using full path to libssl and libcrypto to avoid accidentally picking openssl libs brought in by msan.
+OPENSSL_SUPPORT = -DCPPHTTPLIB_OPENSSL_SUPPORT -I$(OPENSSL_DIR)/include -I$(OPENSSL_DIR)/lib  /usr/local/lib/libssl.a /usr/local/lib/libcrypto.a
+
+ZLIB_SUPPORT = -DCPPHTTPLIB_ZLIB_SUPPORT -lz
+
+BROTLI_DIR = /usr/local/opt/brotli
+# BROTLI_SUPPORT = -DCPPHTTPLIB_BROTLI_SUPPORT -I$(BROTLI_DIR)/include -L$(BROTLI_DIR)/lib -lbrotlicommon -lbrotlienc -lbrotlidec
+
+# Runs all the tests and also fuzz tests against seed corpus.
+all : server_fuzzer
+	./server_fuzzer corpus/*
+
+# Fuzz target, so that you can choose which $(LIB_FUZZING_ENGINE) to use.
+server_fuzzer : server_fuzzer.cc ../../httplib.h
+	$(CXX) $(CXXFLAGS) -o $@  $<  -Wl,-Bstatic $(OPENSSL_SUPPORT)  -Wl,-Bdynamic -ldl  $(ZLIB_SUPPORT)  $(LIB_FUZZING_ENGINE) -pthread
+	zip -q -r server_fuzzer_seed_corpus.zip corpus
+
+clean:
+	rm -f server_fuzzer pem *.0 *.o *.1 *.srl *.zip

test/fuzzing/corpus/1

@@ -0,0 +1 @@
+PUT /search/sample?a=12 HTTP/1.1

test/fuzzing/corpus/2

@@ -0,0 +1,5 @@
+GET /hello.htm HTTP/1.1
+User-Agent: Mozilla/4.0 (compatible; MSIE5.01; Windows NT)
+Accept-Language: en-us
+Accept-Encoding: gzip, deflate
+Connection: Keep-Alive

test/fuzzing/server_fuzzer.cc

@@ -0,0 +1,88 @@
+#include <memory>
+#include <httplib.h>
+
+class FuzzedStream : public httplib::Stream {
+ public:
+  FuzzedStream(const uint8_t* data, size_t size)
+      : data_(data), size_(size), read_pos_(0) {}
+
+  ssize_t read(char* ptr, size_t size) override {
+    if (size + read_pos_ > size_) {
+      size = size_ - read_pos_;
+    }
+    memcpy(ptr, data_ + read_pos_, size);
+    read_pos_ += size;
+    return size;
+  }
+
+  ssize_t write(const char* ptr, size_t size) override {
+    response_.append(ptr, size);
+    return static_cast<int>(size);
+  }
+
+  int write(const char* ptr) { return write(ptr, strlen(ptr)); }
+
+  int write(const std::string& s) { return write(s.data(), s.size()); }
+
+  std::string get_remote_addr() const { return ""; }
+
+  bool is_readable() const override { return true; }
+
+  bool is_writable() const override { return true; }
+
+  void get_remote_ip_and_port(std::string &ip, int &port) const override {
+    ip = "127.0.0.1";
+    port = 8080;
+  }
+
+ private:
+  const uint8_t* data_;
+  size_t size_;
+  size_t read_pos_;
+  std::string response_;
+};
+
+class FuzzableServer : public httplib::Server {
+ public:
+  void ProcessFuzzedRequest(FuzzedStream& stream) {
+    bool connection_close = false;
+    process_request(stream, /*last_connection=*/false, connection_close,
+                    nullptr);
+  }
+};
+
+static FuzzableServer g_server;
+
+extern "C" int LLVMFuzzerInitialize(int* argc, char*** argv) {
+  g_server.Get(R"(.*)",
+                [&](const httplib::Request& req, httplib::Response& res) {
+                  res.set_content("response content", "text/plain");
+                });
+  g_server.Post(R"(.*)",
+                 [&](const httplib::Request& req, httplib::Response& res) {
+                   res.set_content("response content", "text/plain");
+                 });
+  g_server.Put(R"(.*)",
+                [&](const httplib::Request& req, httplib::Response& res) {
+                  res.set_content("response content", "text/plain");
+                });
+  g_server.Patch(R"(.*)",
+                  [&](const httplib::Request& req, httplib::Response& res) {
+                    res.set_content("response content", "text/plain");
+                  });
+  g_server.Delete(R"(.*)",
+                   [&](const httplib::Request& req, httplib::Response& res) {
+                     res.set_content("response content", "text/plain");
+                   });
+  g_server.Options(R"(.*)",
+                    [&](const httplib::Request& req, httplib::Response& res) {
+                      res.set_content("response content", "text/plain");
+                    });
+  return 0;
+}
+
+extern "C" int LLVMFuzzerTestOneInput(const uint8_t* data, size_t size) {
+  FuzzedStream stream{data, size};
+  g_server.ProcessFuzzedRequest(stream);
+  return 0;
+}