Merge pull request #480 from cmeister2/cmeister2/ossfuzz

oss-fuzz: Create a fuzzing target for jansson

.travis.yml

@@ -3,6 +3,7 @@ env:
     - JANSSON_BUILD_METHOD=cmake JANSSON_CMAKE_OPTIONS="-DJANSSON_TEST_WITH_VALGRIND=ON" JANSSON_EXTRA_INSTALL="valgrind"
     - JANSSON_BUILD_METHOD=autotools
     - JANSSON_BUILD_METHOD=coverage JANSSON_CMAKE_OPTIONS="-DJANSSON_COVERAGE=ON -DJANSSON_COVERALLS=ON -DCMAKE_BUILD_TYPE=Debug" JANSSON_EXTRA_INSTALL="lcov curl"
+    - JANSSON_BUILD_METHOD=fuzzer
 language: c
 compiler:
   - gcc
@@ -20,3 +21,4 @@ script:
   - if [ "$JANSSON_BUILD_METHOD" = "autotools" ]; then autoreconf -f -i && CFLAGS=-Werror ./configure && make check; fi
   - if [ "$JANSSON_BUILD_METHOD" = "cmake" ]; then mkdir build && cd build && cmake $JANSSON_CMAKE_OPTIONS .. && cmake --build . && ctest --output-on-failure; fi
   - if [ "$JANSSON_BUILD_METHOD" = "coverage" ]; then mkdir build && cd build && cmake $JANSSON_CMAKE_OPTIONS .. && cmake --build . && cmake --build . --target coveralls; fi
+  - if [ "$JANSSON_BUILD_METHOD" = "fuzzer" ]; then ./test/ossfuzz/travisoss.sh; fi

configure.ac

@@ -9,6 +9,7 @@ AC_CONFIG_HEADERS([jansson_private_config.h])
 
 # Checks for programs.
 AC_PROG_CC
+AC_PROG_CXX
 AC_PROG_LIBTOOL
 AM_CONDITIONAL([GCC], [test x$GCC = xyes])
 
@@ -136,6 +137,19 @@ fi
 AS_IF([test "x$with_Bsymbolic" = "xyes"], [JSON_BSYMBOLIC_LDFLAGS=-Wl[,]-Bsymbolic-functions])
 AC_SUBST(JSON_BSYMBOLIC_LDFLAGS)
 
+
+AC_ARG_ENABLE([ossfuzzers],
+  [AS_HELP_STRING([--enable-ossfuzzers],
+    [Whether to generate the fuzzers for OSS-Fuzz])],
+  [have_ossfuzzers=yes], [have_ossfuzzers=no])
+AM_CONDITIONAL([USE_OSSFUZZERS], [test "x$have_ossfuzzers" = "xyes"])
+
+
+AC_SUBST([LIB_FUZZING_ENGINE])
+AM_CONDITIONAL([USE_OSSFUZZ_FLAG], [test "x$LIB_FUZZING_ENGINE" = "x-fsanitize=fuzzer"])
+AM_CONDITIONAL([USE_OSSFUZZ_STATIC], [test -f "x$LIB_FUZZING_ENGINE"])
+
+
 if test x$GCC = xyes; then
     AC_MSG_CHECKING(for -Wno-format-truncation)
     wnoformat_truncation="-Wno-format-truncation"
@@ -156,6 +170,7 @@ AC_CONFIG_FILES([
         src/jansson_config.h
         test/Makefile
         test/bin/Makefile
+        test/ossfuzz/Makefile
         test/suites/Makefile
         test/suites/api/Makefile
 ])

test/Makefile.am

@@ -1,4 +1,4 @@
-SUBDIRS = bin suites
+SUBDIRS = bin suites ossfuzz
 EXTRA_DIST = scripts run-suites
 
 TESTS = run-suites

test/ossfuzz/.gitignore

@@ -0,0 +1 @@
+json_load_dump_fuzzer

test/ossfuzz/Makefile.am

@@ -0,0 +1,32 @@
+AM_CPPFLAGS = -I$(top_builddir)/src -I$(top_srcdir)/src
+LDADD = $(top_builddir)/src/libjansson.la
+
+if USE_OSSFUZZ_FLAG
+FUZZ_FLAG = $(LIB_FUZZING_ENGINE)
+else
+if USE_OSSFUZZ_STATIC
+LDADD += $(LIB_FUZZING_ENGINE)
+FUZZ_FLAG =
+else
+LDADD += libstandaloneengine.a
+FUZZ_FLAG =
+endif
+endif
+
+noinst_PROGRAMS =
+noinst_LIBRARIES =
+
+if USE_OSSFUZZERS
+noinst_PROGRAMS += \
+	json_load_dump_fuzzer
+
+noinst_LIBRARIES += \
+	libstandaloneengine.a
+endif
+
+json_load_dump_fuzzer_SOURCES = json_load_dump_fuzzer.cc testinput.h
+json_load_dump_fuzzer_CXXFLAGS = $(AM_CXXFLAGS) $(FUZZ_FLAG)
+json_load_dump_fuzzer_LDFLAGS = $(AM_LDFLAGS) -static
+
+libstandaloneengine_a_SOURCES = standaloneengine.cc
+libstandaloneengine_a_CXXFLAGS = $(AM_CXXFLAGS)

test/ossfuzz/json_load_dump_fuzzer.cc

@@ -0,0 +1,47 @@
+#include <stdint.h>
+#include <sys/types.h>
+
+#include "jansson.h"
+
+extern "C" int LLVMFuzzerTestOneInput(const uint8_t *data, size_t size)
+{
+  json_error_t error;
+
+  if (size < sizeof(size_t) + sizeof(size_t))
+  {
+    return 0;
+  }
+
+  // Use the first sizeof(size_t) bytes as load flags.
+  size_t load_flags = *(const size_t*)data;
+  data += sizeof(size_t);
+  size -= sizeof(size_t);
+
+  // Use the next sizeof(size_t) bytes as dump flags.
+  size_t dump_flags = *(const size_t*)data;
+  data += sizeof(size_t);
+  size -= sizeof(size_t);
+
+  // Attempt to load the remainder of the data with the given load flags.
+  const char* text = reinterpret_cast<const char *>(data);
+  json_t* jobj = json_loadb(text, size, load_flags, &error);
+
+  if (jobj == NULL)
+  {
+    return 0;
+  }
+
+  // Attempt to dump the loaded json object with the given dump flags.
+  char* out = json_dumps(jobj, dump_flags);
+  if (out)
+  {
+    free(out);
+  }
+
+  if (jobj)
+  {
+    json_decref(jobj);
+  }
+
+  return 0;
+}

test/ossfuzz/ossfuzz.sh

@@ -0,0 +1,27 @@
+#!/bin/bash -eu
+
+# This script is called by the oss-fuzz main project when compiling the fuzz
+# targets. This script is regression tested by travisoss.sh.
+
+# Save off the current folder as the build root.
+export BUILD_ROOT=$PWD
+
+echo "CC: $CC"
+echo "CXX: $CXX"
+echo "LIB_FUZZING_ENGINE: $LIB_FUZZING_ENGINE"
+echo "CFLAGS: $CFLAGS"
+echo "CXXFLAGS: $CXXFLAGS"
+echo "OUT: $OUT"
+
+export MAKEFLAGS+="-j$(nproc)"
+
+# Install dependencies
+apt-get -y install automake libtool
+
+# Compile the fuzzer.
+autoreconf -i
+./configure --enable-ossfuzzers
+make
+
+# Copy the fuzzer to the output directory.
+cp -v test/ossfuzz/json_load_dump_fuzzer $OUT/

test/ossfuzz/standaloneengine.cc

@@ -0,0 +1,74 @@
+#include <stdint.h>
+#include <stdio.h>
+#include <stdlib.h>
+
+#include "testinput.h"
+
+/**
+ * Main procedure for standalone fuzzing engine.
+ *
+ * Reads filenames from the argument array. For each filename, read the file
+ * into memory and then call the fuzzing interface with the data.
+ */
+int main(int argc, char **argv)
+{
+  int ii;
+  for(ii = 1; ii < argc; ii++)
+  {
+    FILE *infile;
+    printf("[%s] ", argv[ii]);
+
+    /* Try and open the file. */
+    infile = fopen(argv[ii], "rb");
+    if(infile)
+    {
+      uint8_t *buffer = NULL;
+      size_t buffer_len;
+
+      printf("Opened.. ");
+
+      /* Get the length of the file. */
+      fseek(infile, 0L, SEEK_END);
+      buffer_len = ftell(infile);
+
+      /* Reset the file indicator to the beginning of the file. */
+      fseek(infile, 0L, SEEK_SET);
+
+      /* Allocate a buffer for the file contents. */
+      buffer = (uint8_t *)calloc(buffer_len, sizeof(uint8_t));
+      if(buffer)
+      {
+        /* Read all the text from the file into the buffer. */
+        fread(buffer, sizeof(uint8_t), buffer_len, infile);
+        printf("Read %zu bytes, fuzzing.. ", buffer_len);
+
+        /* Call the fuzzer with the data. */
+        LLVMFuzzerTestOneInput(buffer, buffer_len);
+
+        printf("complete !!");
+
+        /* Free the buffer as it's no longer needed. */
+        free(buffer);
+        buffer = NULL;
+      }
+      else
+      {
+        fprintf(stderr,
+                "[%s] Failed to allocate %zu bytes \n",
+                argv[ii],
+                buffer_len);
+      }
+
+      /* Close the file as it's no longer needed. */
+      fclose(infile);
+      infile = NULL;
+    }
+    else
+    {
+      /* Failed to open the file. Maybe wrong name or wrong permissions? */
+      fprintf(stderr, "[%s] Open failed. \n", argv[ii]);
+    }
+
+    printf("\n");
+  }
+}

test/ossfuzz/testinput.h

@@ -0,0 +1,3 @@
+#include <inttypes.h>
+
+extern "C" int LLVMFuzzerTestOneInput(const uint8_t *data, size_t size);

test/ossfuzz/travisoss.sh

@@ -0,0 +1,26 @@
+#!/bin/bash
+
+set -ex
+
+PROJECT_NAME=jansson
+
+# Clone the oss-fuzz repository
+git clone https://github.com/google/oss-fuzz.git /tmp/ossfuzz
+
+if [[ ! -d /tmp/ossfuzz/projects/${PROJECT_NAME} ]]
+then
+    echo "Could not find the ${PROJECT_NAME} project in ossfuzz"
+
+    # Exit with a success code while the jansson project is not expected to exist
+    # on oss-fuzz.
+    exit 0
+fi
+
+# Modify the oss-fuzz Dockerfile so that we're checking out the current branch on travis.
+sed -i "s@https://github.com/akheron/jansson.git@-b $TRAVIS_BRANCH https://github.com/akheron/jansson.git@" /tmp/ossfuzz/projects/${PROJECT_NAME}/Dockerfile
+
+# Try and build the fuzzers
+pushd /tmp/ossfuzz
+python infra/helper.py build_image --pull ${PROJECT_NAME}
+python infra/helper.py build_fuzzers ${PROJECT_NAME}
+popd