cmake: Build ssh_server_fuzzer if enabled

Fixes T67

Signed-off-by: Andreas Schneider <asn@cryptomilk.org>

DefineOptions.cmake

@@ -14,7 +14,8 @@ option(WITH_TESTING "Build with unit tests" OFF)
 option(WITH_CLIENT_TESTING "Build with client tests; requires a running sshd" OFF)
 option(WITH_BENCHMARKS "Build benchmarks tools" OFF)
 option(WITH_EXAMPLES "Build examples" ON)
-option(WITH_NACL "Build with libnacl (curve25519" ON)
+option(WITH_NACL "Build with libnacl (curve25519)" ON)
+option(FUZZ_TESTING "Build with fuzzer for the server" OFF)
 if (WITH_ZLIB)
     set(WITH_LIBZ ON)
 else (WITH_ZLIB)

cmake/Modules/FindClangFuzzer.cmake

@@ -0,0 +1,32 @@
+# - Try to find Fuzzer
+# Once done this will define
+#
+#  CLANG_FUZZER_FOUND - system has Fuzzer
+#  CLANG_FUZZER_LIBRARY - Link these to use Fuzzer
+#
+#=============================================================================
+#  Copyright (c) 2018 Andreas Schneider <asn@cryptomilk.org>
+#
+#  Distributed under the OSI-approved BSD License (the "License");
+#  see accompanying file Copyright.txt for details.
+#
+#  This software is distributed WITHOUT ANY WARRANTY; without even the
+#  implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
+#  See the License for more information.
+#=============================================================================
+#
+
+find_package(Clang REQUIRED CONFIG)
+
+find_library(CLANG_FUZZER_LIBRARY
+    NAMES
+        Fuzzer
+    HINTS
+        ${LLVM_LIBRARY_DIR}/clang/${LLVM_PACKAGE_VERSION}/lib
+)
+
+include(FindPackageHandleStandardArgs)
+find_package_handle_standard_args(Fuzzer DEFAULT_MSG CLANG_FUZZER_LIBRARY)
+
+# show the CLANG_FUZZER_LIBRARY variables only in the advanced view
+mark_as_advanced(CLANG_FUZZER_LIBRARY)

tests/CMakeLists.txt

@@ -138,3 +138,7 @@ endif (WITH_BENCHMARKS)
 if (WITH_SERVER)
     add_subdirectory(pkd)
 endif (WITH_SERVER)
+
+if (FUZZ_TESTING)
+    add_subdirectory(fuzz)
+endif()

tests/fuzz/CMakeLists.txt

@@ -0,0 +1,9 @@
+project(fuzzing CXX)
+
+find_package(ClangFuzzer)
+
+add_executable(ssh_server_fuzzer ssh_server_fuzzer.cpp)
+target_link_libraries(ssh_server_fuzzer
+    ${CLANG_FUZZER_LIBRARY}
+    ${LIBSSH_THREADS_STATIC_LIBRARY}
+    ${LIBSSH_THREADS_LINK_LIBRARIES})