Add an initial libfuzzer based fuzzer for the admin console

Run the actual fuzzer like this:

./admin_fuzzer -max_len=16384 fuzzer/admin-data/

Change-Id: I5891df8033ff1837afce86775ee62447587f2f20
Reviewed-on: https://gerrit.libreoffice.org/c/online/+/91504
Tested-by: Jenkins CollaboraOffice <jenkinscollaboraoffice@gmail.com>
Reviewed-by: Miklos Vajna <vmiklos@collabora.com>

Makefile.am

@@ -131,7 +131,9 @@ noinst_PROGRAMS = clientnb \
                   loolsocketdump
 
 if ENABLE_LIBFUZZER
-noinst_PROGRAMS += clientsession_fuzzer
+noinst_PROGRAMS += \
+		   admin_fuzzer \
+		   clientsession_fuzzer
 else
 noinst_PROGRAMS += loolwsd_fuzzer
 endif
@@ -161,6 +163,16 @@ loolwsd_fuzzer_SOURCES = $(loolwsd_sources) \
                          $(shared_sources) \
                          kit/DummyLibreOfficeKit.cpp
 
+admin_fuzzer_CPPFLAGS = \
+			-DKIT_IN_PROCESS=1 \
+			$(AM_CPPFLAGS)
+admin_fuzzer_SOURCES = \
+		       $(loolwsd_sources) \
+		       $(loolforkit_sources) \
+		       $(shared_sources) \
+		       fuzzer/Admin.cpp
+admin_fuzzer_LDFLAGS = -fsanitize=fuzzer $(AM_LDFLAGS)
+
 clientsession_fuzzer_CPPFLAGS = \
 				-DKIT_IN_PROCESS=1 \
 				$(AM_CPPFLAGS)

fuzzer/Admin.cpp

@@ -0,0 +1,22 @@
+#include <iostream>
+
+#include "Admin.hpp"
+
+extern "C" int LLVMFuzzerTestOneInput(const uint8_t* data, size_t size)
+{
+    Admin& admin = Admin::instance();
+    auto handler = std::make_shared<AdminSocketHandler>(&admin);
+
+    std::string input(reinterpret_cast<const char*>(data), size);
+    std::stringstream ss(input);
+    std::string line;
+    while (std::getline(ss, line, '\n'))
+    {
+        std::vector<char> lineVector(line.data(), line.data() + line.size());
+        handler->handleMessage(lineVector);
+    }
+
+    return 0;
+}
+
+/* vim:set shiftwidth=4 softtabstop=4 expandtab: */

fuzzer/admin-data/load

@@ -0,0 +1,9 @@
+auth jwt=eyJhbGciOiJSUzI1NiIsInR5cCI6IkpXVCJ9.eyJpc3MiOiJsb29sIiwic3ViIjoiYWRtaW4iLCJhdWQiOiJhZG1pbiIsIm5tZSI6ImFkbWluIiwiZXhwIjoiMTU4NTU3ODM1NiJ9.v_VuMvhuUHlcQN-vTzPl3UzIbkmXd5brIVc_RjSa10KjOo9lG6JXw1Jpvin1pbP2Q4QtyQo5o9yGlVW_JdMoA7neeQkq4FwA2MCJzXu9Kp62SB8KVqDkVafNBS4ZV_oGLU8tAjuGDWPC9oZj4H-07j6L9LC3SWbKlLUvdsC5nixXRiijHj6TWP_7HnVrPX1OuaaJM47Q--Wu7_3fI5pj4OLKYzLPX6ONlhO3YQKY1GaVLvIzbRo2J-A0x0KFk_k0JWo6dEtSK3Hr47xxyn3nt1AuyHowgxO8G2IKPGcFjrMcyKS2khh3DGNa5Re21Jm-e3LhtNX-sCpWnXhTuQqBxQ
+documents
+subscribe adddoc rmdoc resetidle propchange modifications
+mem_consumed
+active_docs_count
+active_users_count
+sent_bytes
+recv_bytes
+uptime

net/WebSocketHandler.hpp

@@ -540,7 +540,7 @@ public:
     int sendMessage(const char* data, const size_t len, const WSOpCode code, const bool flush = true) const
     {
         int unitReturn = -1;
-        if (UnitBase::get().filterSendMessage(data, len, code, flush, unitReturn))
+        if (!Util::isFuzzing() && UnitBase::get().filterSendMessage(data, len, code, flush, unitReturn))
             return unitReturn;
 
         //TODO: Support fragmented messages.

wsd/Admin.cpp

@@ -283,7 +283,11 @@ AdminSocketHandler::AdminSocketHandler(Admin* adminManager)
 
 void AdminSocketHandler::sendTextFrame(const std::string& message)
 {
-    UnitWSD::get().onAdminQueryMessage(message);
+    if (!Util::isFuzzing())
+    {
+        UnitWSD::get().onAdminQueryMessage(message);
+    }
+
     if (_isAuthenticated)
     {
         LOG_TRC("send admin text frame '" << message << "'");

wsd/Admin.hpp

@@ -38,13 +38,13 @@ public:
 
     static void subscribeAsync(const std::shared_ptr<AdminSocketHandler>& handler);
 
+    /// Process incoming websocket messages
+    void handleMessage(const std::vector<char> &data) override;
+
 private:
     /// Sends text frames simply to authenticated clients.
     void sendTextFrame(const std::string& message);
 
-    /// Process incoming websocket messages
-    void handleMessage(const std::vector<char> &data) override;
-
 private:
     Admin* _admin;
     int _sessionId;

wsd/Auth.cpp

@@ -146,7 +146,7 @@ bool JWTAuth::verify(const std::string& accessToken)
 
         std::chrono::system_clock::time_point now = std::chrono::system_clock::now();
         std::time_t curtime = std::chrono::system_clock::to_time_t(now);
-        if (curtime > decodedExptime)
+        if (!Util::isFuzzing() && curtime > decodedExptime)
         {
             LOG_INF("JWTAuth:verify: JWT expired; curtime:" << curtime << ", exp:" << decodedExptime);
             return false;