fuzzing support (#982)

Adding fuzzing to finding memory-corruption-related bugs.

Hello coturn team,
Can you check this pr harness suite for creating harnesses and compiling
harnesses?
Any other thoughts on adding a new interface for fuzzing support ?


Signed-off-by: 0x34d <ajsinghyadav00@gmail.com>

Signed-off-by: 0x34d <ajsinghyadav00@gmail.com>

CMakeLists.txt

@@ -8,6 +8,8 @@ set(CMAKE_MODULE_PATH ${CMAKE_MODULE_PATH} ${CMAKE_SOURCE_DIR}/cmake)
 # TODO: Modify this when the version is released
 SET(BUILD_VERSION "4.5.2")
 
+option(FUZZER "Build oss-fuzz fuzzing" OFF)
+
 # Find Git Version Patch
 IF(EXISTS "${CMAKE_SOURCE_DIR}/.git")
     if(NOT GIT)
@@ -118,3 +120,12 @@ install(DIRECTORY
     DESTINATION share/examples/turnserver
     PATTERN "rfc5769.sh" EXCLUDE
     )
+
+if(FUZZER)
+    if (NOT CMAKE_C_COMPILER_ID STREQUAL "Clang")
+        message(FATAL_ERROR "clang is require for libFuzzer")
+    endif()
+
+    add_subdirectory(fuzzing)
+
+endif()

fuzzing/CMakeLists.txt

@@ -0,0 +1,17 @@
+add_executable(FuzzStun FuzzStun.c)
+target_link_libraries(FuzzStun turnclient ${LIB_FUZZING_ENGINE})
+
+file(COPY ${CMAKE_CURRENT_SOURCE_DIR}/input/FuzzStun_seed_corpus.zip
+        DESTINATION ${CMAKE_CURRENT_BINARY_DIR})
+
+
+set(FuzzStunClientSRC
+    ${CMAKE_CURRENT_SOURCE_DIR}/FuzzStunClient.c
+    ${PROJECT_SOURCE_DIR}/src/apps/common/stun_buffer.c
+)
+
+add_executable(FuzzStunClient ${FuzzStunClientSRC})
+target_link_libraries(FuzzStunClient turnclient ${LIB_FUZZING_ENGINE})
+
+file(COPY ${CMAKE_CURRENT_SOURCE_DIR}/input/FuzzStunClient_seed_corpus.zip
+        DESTINATION ${CMAKE_CURRENT_BINARY_DIR})

fuzzing/FuzzStun.c

@@ -0,0 +1,28 @@
+#include <stdlib.h>
+#include <stdio.h>
+#include <string.h>
+
+#include "ns_turn_utils.h"
+#include "apputils.h"
+#include "stun_buffer.h"
+
+static SHATYPE shatype = SHATYPE_SHA1;
+
+#define kMinInputLength 10
+#define kMaxInputLength 5120
+
+extern int LLVMFuzzerTestOneInput(const uint8_t *Data, size_t Size) {//rfc5769check
+
+    if (Size < kMinInputLength || Size > kMaxInputLength){
+        return 1;
+    }
+
+    stun_is_command_message_full_check_str((uint8_t *)Data, Size, 1, NULL);
+
+    uint8_t uname[33];
+    uint8_t realm[33];
+    uint8_t upwd[33];
+    strcpy((char*) upwd, "VOkJxbRl1RmTxUk/WvJxBt");
+    stun_check_message_integrity_str(TURN_CREDENTIALS_SHORT_TERM,(uint8_t *)Data, Size, uname, realm, upwd, shatype);
+    return 0;
+}

fuzzing/FuzzStunClient.c

@@ -0,0 +1,34 @@
+#include <stdlib.h>
+#include <stdio.h>
+#include <string.h>
+
+#include "ns_turn_utils.h"
+#include "apputils.h"
+#include "stun_buffer.h"
+
+#define kMinInputLength 10
+#define kMaxInputLength 5120
+
+extern int LLVMFuzzerTestOneInput(const uint8_t *Data, size_t Size) {//stunclient.c
+
+    if (Size < kMinInputLength || Size > kMaxInputLength){
+        return 1;
+    }
+
+    stun_buffer buf;
+
+    buf.len = Size;
+    memcpy(buf.buf,Data,buf.len);
+
+    if(stun_is_command_message(&buf)){
+        if(stun_is_response(&buf)){
+            if(stun_is_success_response(&buf)){
+                if(stun_is_binding_response(&buf)){
+                    return 0;
+                }
+            }
+        }
+    }
+
+    return 1;
+}

fuzzing/build.sh

@@ -0,0 +1,51 @@
+#!/bin/bash -eu
+
+build(){
+   export CFLAGS="$1"
+   export CXXFLAGS="$1"
+   export LIB_FUZZING_ENGINE=-fsanitize=fuzzer
+
+   mkdir build && cd build/
+   cmake -DFUZZER=ON -DLIB_FUZZING_ENGINE="$LIB_FUZZING_ENGINE" ../../.
+   make -j$(nproc)
+
+   cd fuzzing/
+   unzip FuzzStun_seed_corpus.zip
+   unzip FuzzStunClient_seed_corpus.zip
+
+   mkdir FuzzStun_Corpus
+   mkdir FuzzStunClient_Corpus
+}
+
+run(){
+   DIR=build/fuzzing
+   if [ $1 == '0' ]
+   then
+      ./$DIR/FuzzStun   $DIR/FuzzStun_Corpus/   $DIR/FuzzStun_seed_corpus
+   else
+      ./$DIR/FuzzStunClient   $DIR/FuzzStunClient_Corpus/   $DIR/FuzzStunClient_seed_corpus
+   fi   
+}
+
+help(){
+   echo "use: ./$0 ASan | UBSan | MSan | Run 0 | Run 1"
+}
+
+if [ -z "$1" ]
+then
+   help
+elif [ $1 == "ASan" ]
+then
+   build "-O1 -fno-omit-frame-pointer -gline-tables-only -DFUZZING_BUILD_MODE_UNSAFE_FOR_PRODUCTION -fsanitize=address -fsanitize-address-use-after-scope -fsanitize=fuzzer-no-link"
+elif [ "$1" == "UBSan" ]
+then
+   build "-O1 -fno-omit-frame-pointer -gline-tables-only -DFUZZING_BUILD_MODE_UNSAFE_FOR_PRODUCTION -fsanitize=array-bounds,bool,builtin,enum,float-divide-by-zero,function,integer-divide-by-zero,null,object-size,return,returns-nonnull-attribute,shift,signed-integer-overflow,unsigned-integer-overflow,unreachable,vla-bound,vptr -fno-sanitize-recover=array-bounds,bool,builtin,enum,float-divide-by-zero,function,integer-divide-by-zero,null,object-size,return,returns-nonnull-attribute,shift,signed-integer-overflow,unreachable,vla-bound,vptr -fsanitize=fuzzer-no-link"
+elif [ "$1" == "MSan" ]
+then
+   build "-O1 -fno-omit-frame-pointer -gline-tables-only -DFUZZING_BUILD_MODE_UNSAFE_FOR_PRODUCTION -fsanitize=memory -fsanitize-memory-track-origins -fsanitize=fuzzer-no-link"
+elif [ "$1" == "Run" ]
+then
+   run $2
+else
+  help
+fi