blob: a70d2a39a2f9c322143809e4cd5df79a6ff9575e [file] [log] [blame]
// Copyright 2017 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#include <assert.h>
#include <stdlib.h>
#include <iostream>
// Includes copied from
#include "base/at_exit.h"
#include "base/i18n/icu_util.h"
#include "url/gurl.h"
// Includes *not* copied from
// Contains DEFINE_BINARY_PROTO_FUZZER, a macro we use to define our target
// function.
#include "third_party/libprotobuf-mutator/src/src/libfuzzer/libfuzzer_macro.h"
// Header information about the Protocol Buffer Url class.
#include "testing/libfuzzer/fuzzers/url.pb.h"
// The code using TestCase is copied from
struct TestCase {
TestCase() {
// used by ICU integration.
base::AtExitManager at_exit_manager;
TestCase* test_case = new TestCase();
// Silence logging from the protobuf library.
protobuf_mutator::protobuf::LogSilencer log_silencer;
std::string Slash_to_string(int slash) {
if (slash == url_parse_proto_fuzzer::Url::NONE)
return "";
if (slash == url_parse_proto_fuzzer::Url::FORWARD)
return "/";
if (slash == url_parse_proto_fuzzer::Url::BACKWARD) {
return "\\";
assert(false && "Received unexpected value for slash");
// Silence compiler warning about not returning in non-void function.
return "";
// Converts a URL in Protocol Buffer format to a url in string format.
// Since protobuf is a relatively simple format, fuzzing targets that do not
// accept protobufs (such as this one) will require code to convert from
// protobuf to the accepted format (string in this case).
std::string protobuf_to_string(const url_parse_proto_fuzzer::Url& url) {
// Build url_string piece by piece from url and then return it.
std::string url_string = std::string("");
if (url.has_scheme()) { // Get the scheme if Url has it.
// Append the scheme to the url. This may be empty. Then append a colon
// which is mandatory if there is a scheme.
url_string += url.scheme() + ":";
// Just append the slashes without doing validation, since it would be too
// complex. libFuzzer will hopefully figure out good values.
for (const int slash : url.slashes())
url_string += Slash_to_string(slash);
// Get host. This is simple since hosts are simply strings according to our
// definition.
if (url.has_host()) {
// Get userinfo if libFuzzer set it. Ensure that user is seperated
// from the password by ":" (if a password is included) and that userinfo is
// separated from the host by "@".
if (url.has_userinfo()) {
url_string += url.userinfo().user();
if (url.userinfo().has_password()) {
url_string += ":";
url_string += url.userinfo().password();
url_string += "@";
url_string +=;
// As explained in url.proto, if libFuzzer included a port in url ensure
// that it is preceded by the host and then ":".
if (url.has_port())
// Convert url.port() from an unsigned 32 bit int before appending it.
url_string += ":" + std::to_string(url.port());
// Append the path segments to the url, with each segment separated by
// the path_separator.
bool first_segment = true;
std::string path_separator = Slash_to_string(url.path_separator());
for (const std::string& path_segment : url.path()) {
// There does not need to be a path, but if there is a path and a host,
// ensure the path begins with "/".
if (url.has_host() && first_segment) {
url_string += "/" + path_segment;
first_segment = false;
} else
url_string += path_separator + path_segment;
// Queries must be started by "?". If libFuzzer included a query in url,
// ensure that it is preceded by "?". Also Seperate query components with
// ampersands as is the convention.
bool first_component = true;
for (const std::string& query_component : url.query()) {
if (first_component) {
url_string += "?" + query_component;
first_component = false;
} else
url_string += "&" + query_component;
// Fragments must be started by "#". If libFuzzer included a fragment
// in url, ensure that it is preceded by "#".
if (url.has_fragment())
url_string += "#" + url.fragment();
return url_string;
// The target function. This is the equivalent of LLVMFuzzerTestOneInput in
// typical libFuzzer based fuzzers. It is passed our Url protobuf object that
// was mutated by libFuzzer, converts it to a string and then feeds it to url()
// for fuzzing.
DEFINE_BINARY_PROTO_FUZZER(const url_parse_proto_fuzzer::Url& url_protobuf) {
std::string url_string = protobuf_to_string(url_protobuf);
// Allow native input to be retrieved easily.
// Note that there will be a trailing newline that is not part of url_string.
if (getenv("LPM_DUMP_NATIVE_INPUT"))
std::cout << url_string << std::endl;
GURL url(url_string);