From 3a3b188affa752df7703a63b742dc5fb760501b2 Mon Sep 17 00:00:00 2001
From: Bohdan <bogdan@soramitsu.co.jp>
Date: Mon, 11 Mar 2019 12:25:07 +0200
Subject: [PATCH] Add fuzzing targets (#23)

* Add fuzzing targets

Signed-off-by: Bogdan Vaneev <warchantua@gmail.com>

* Add init to fuzz sign

Signed-off-by: Bogdan Vaneev <warchantua@gmail.com>
---
 CMakeLists.txt               |  7 ++++++
 cmake/ed25519_add_fuzz.cmake |  8 +++++++
 fuzzing/CMakeLists.txt       | 43 ++++++++++++++++++++++++++++++++++++
 fuzzing/fuzz_sign.cc         | 22 ++++++++++++++++++
 test/ed25519/CMakeLists.txt  | 16 +++++++++-----
 5 files changed, 90 insertions(+), 6 deletions(-)
 create mode 100644 cmake/ed25519_add_fuzz.cmake
 create mode 100644 fuzzing/CMakeLists.txt
 create mode 100644 fuzzing/fuzz_sign.cc

diff --git a/CMakeLists.txt b/CMakeLists.txt
index 723ac27..ab2f207 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -40,6 +40,7 @@ set(CMAKE_CXX_EXTENSIONS OFF)
 option(TESTING "Enable testing" OFF)
 option(COVERAGE "Enable coverage" OFF)
 option(BENCHMARKING "Enable benchmarking" OFF)
+option(FUZZING "Enable fuzzing targets" OFF)
 
 include_directories(
   ${CMAKE_BINARY_DIR}/
@@ -54,6 +55,7 @@ include(cmake/ed25519_target_link_libraries.cmake)
 include(cmake/ed25519_add_library.cmake)
 include(cmake/ed25519_merge_libraries.cmake)
 include(cmake/ed25519_add_test.cmake)
+include(cmake/ed25519_add_fuzz.cmake)
 include(cmake/ed25519_select_supported_impl.cmake)
 test_build_amd64(CAN_BUILD_AMD64)
 
@@ -159,3 +161,8 @@ endif ()
 if (BENCHMARK)
   add_subdirectory(benchmark)
 endif ()
+
+
+if (FUZZING)
+  add_subdirectory(fuzzing)
+endif ()
diff --git a/cmake/ed25519_add_fuzz.cmake b/cmake/ed25519_add_fuzz.cmake
new file mode 100644
index 0000000..0835aa7
--- /dev/null
+++ b/cmake/ed25519_add_fuzz.cmake
@@ -0,0 +1,8 @@
+function(ed25519_add_fuzz fuzz_name)
+  add_executable(${fuzz_name} ${ARGN})
+  set_target_properties(${fuzz_name} PROPERTIES
+    RUNTIME_OUTPUT_DIRECTORY ${CMAKE_BINARY_DIR}/fuzz_bin
+    ARCHIVE_OUTPUT_PATH      ${CMAKE_BINARY_DIR}/fuzz_lib
+    LIBRARY_OUTPUT_PATH      ${CMAKE_BINARY_DIR}/fuzz_lib
+    )
+endfunction()
diff --git a/fuzzing/CMakeLists.txt b/fuzzing/CMakeLists.txt
new file mode 100644
index 0000000..ded66f7
--- /dev/null
+++ b/fuzzing/CMakeLists.txt
@@ -0,0 +1,43 @@
+# Copyright Soramitsu Co., Ltd. All Rights Reserved.
+# SPDX-License-Identifier: Apache-2.0
+
+set(compiler  "clang-7")
+set(flags     "-g -O1")
+set(options   "-fsanitize=fuzzer,undefined")
+
+set(CMAKE_C_COMPILER    ${compiler})
+set(CMAKE_CXX_COMPILER  ${compiler})
+set(CMAKE_C_FLAGS       ${flags})
+set(CMAKE_CXX_FLAGS     ${flags})
+
+add_compile_options(${options})
+add_link_options(${options})
+
+
+set(_random ${RANDOM})
+foreach(_edimpl ${ED25519_SUPPORTED_LIBRARIES_EDIMPL})
+  foreach(_hash ${ED25519_SUPPORTED_LIBRARIES_HASH})
+    foreach(_build STATIC SHARED)
+
+      set(_target ${_edimpl}-${_hash}-${_random}-${_build})
+
+      if(NOT TARGET ${edtarget})
+        ed25519_merge_libraries(fuzz-ed25519-${_target} ${_build}
+          LIBRARIES
+          ${_edimpl}
+          ${_hash}
+          ${_random}
+          )
+      endif()
+
+
+      ed25519_add_fuzz(fuzz-sign-${_target}
+        fuzz_sign.cc
+        )
+      ed25519_target_link_libraries(fuzz-sign-${_target}
+        fuzz-ed25519-${_target}
+        )
+
+    endforeach()
+  endforeach()
+endforeach()
diff --git a/fuzzing/fuzz_sign.cc b/fuzzing/fuzz_sign.cc
new file mode 100644
index 0000000..5fe32b9
--- /dev/null
+++ b/fuzzing/fuzz_sign.cc
@@ -0,0 +1,22 @@
+/**
+ * Copyright Soramitsu Co., Ltd. All Rights Reserved.
+ * SPDX-License-Identifier: Apache-2.0
+ */
+ 
+#include <stdlib.h>
+#include <stdint.h>
+#include <ed25519/ed25519.h>
+
+static public_key_t pub;
+static private_key_t priv;
+static signature_t sig;
+
+extern "C" int LLVMFuzzerInitialize(int argc, char** argv){
+  ed25519_create_keypair(&priv, &pub);
+  return 0;
+}
+
+extern "C" int LLVMFuzzerTestOneInput(const uint8_t *Data, size_t Size) {
+  ed25519_sign(&sig, Data, Size, &pub, &priv);
+  return 0;  // Non-zero return values are reserved for future use.
+}
diff --git a/test/ed25519/CMakeLists.txt b/test/ed25519/CMakeLists.txt
index d908ba3..5840319 100644
--- a/test/ed25519/CMakeLists.txt
+++ b/test/ed25519/CMakeLists.txt
@@ -4,12 +4,16 @@ foreach(_edimpl ${ED25519_SUPPORTED_LIBRARIES_EDIMPL})
     foreach(_build STATIC SHARED)
 
       set(_target ${_edimpl}-${_hash}-${_random}-${_build})
-      ed25519_merge_libraries(ed25519-${_target} ${_build}
-        LIBRARIES
-          ${_edimpl}
-          ${_hash}
-          ${_random}
-        )
+
+      if(NOT TARGET ed25519-${_target})
+        ed25519_merge_libraries(ed25519-${_target} ${_build}
+          LIBRARIES
+            ${_edimpl}
+            ${_hash}
+            ${_random}
+          )
+      endif()
+
       ed25519_add_test(test-${_target}
         ed25519_test.cpp
         )