diff options
Diffstat (limited to 'NorthstarDedicatedTest/ExploitFixes.cpp')
-rw-r--r-- | NorthstarDedicatedTest/ExploitFixes.cpp | 415 |
1 files changed, 0 insertions, 415 deletions
diff --git a/NorthstarDedicatedTest/ExploitFixes.cpp b/NorthstarDedicatedTest/ExploitFixes.cpp deleted file mode 100644 index 154091df..00000000 --- a/NorthstarDedicatedTest/ExploitFixes.cpp +++ /dev/null @@ -1,415 +0,0 @@ -#include "pch.h" - -#include "ExploitFixes.h" -#include "ExploitFixes_UTF8Parser.h" -#include "NSMem.h" -#include "cvar.h" -#include "tier0.h" - -ConVar* ns_exploitfixes_log; -#define SHOULD_LOG (ns_exploitfixes_log->m_Value.m_nValue > 0) -#define BLOCKED_INFO(s) \ - ( \ - [=]() -> bool \ - { \ - if (SHOULD_LOG) \ - { \ - std::stringstream stream; \ - stream << "ExploitFixes.cpp: " << BLOCK_PREFIX << s; \ - spdlog::error(stream.str()); \ - } \ - return false; \ - }()) - -// Make sure 3 or less floats are valid -bool ValidateFloats(float a, float b = 0, float c = 0) -{ - return !isnan(a) && !isnan(b) && !isnan(c); -} - -struct Vector -{ - float x, y, z; - - Vector(float x = 0, float y = 0, float z = 0) : x(x), y(y), z(z) {} - - bool IsValid() - { - return ValidateFloats(x, y, z); - } -}; - -struct Angle -{ - float pitch, yaw, roll; - - Angle(float pitch = 0, float yaw = 0, float roll = 0) : pitch(pitch), yaw(yaw), roll(roll) {} - - bool IsInvalid() - { - return !ValidateFloats(pitch, yaw, roll); - - if (!ValidateFloats(pitch, yaw, roll)) - return false; - - return (pitch > 90 || pitch < -90) || (yaw > 180 || yaw < -180) || (roll > 180 || roll < -180); - } -}; - -#define BLOCK_NETMSG_FUNC(name, pattern) \ - KHOOK(name, ("engine.dll", pattern), bool, __fastcall, (void* thisptr, void* buffer)) \ - { \ - return false; \ - } - -// Servers can literally request a screenshot from any client, yeah no -BLOCK_NETMSG_FUNC(CLC_Screenshot_WriteToBuffer, "48 89 5C 24 ? 57 48 83 EC 20 8B 42 10"); -BLOCK_NETMSG_FUNC(CLC_Screenshot_ReadFromBuffer, "48 89 5C 24 ? 48 89 6C 24 ? 48 89 74 24 ? 57 48 83 EC 20 48 8B DA 48 8B 52 38"); - -// This is unused ingame and a big exploit vector -BLOCK_NETMSG_FUNC(Base_CmdKeyValues_ReadFromBuffer, "40 55 48 81 EC ? ? ? ? 48 8D 6C 24 ? 48 89 5D 70"); - -KHOOK(CClient_ProcessSetConVar, ("engine.dll", "48 8B D1 48 8B 49 18 48 8B 01 48 FF 60 10"), bool, __fastcall, (void* pMsg)) -{ - - constexpr int ENTRY_STR_LEN = 260; - struct SetConVarEntry - { - char name[ENTRY_STR_LEN]; - char val[ENTRY_STR_LEN]; - }; - - struct NET_SetConVar - { - void* vtable; - void* unk1; - void* unk2; - void* m_pMessageHandler; - SetConVarEntry* m_ConVars; // convar entry array - void* unk5; // these 2 unks are just vector capacity or whatever - void* unk6; - int m_ConVars_count; // amount of cvar entries in array (this will not be out of bounds) - }; - - auto msg = (NET_SetConVar*)pMsg; - - bool areWeServer; - - { - // Figure out of we are the client or the server - // To do this, we utilize the msg's m_pMessageHandler pointer - // m_pMessageHandler points to a virtual class that handles all net messages - // The first virtual table function of our m_pMessageHandler will differ if it is IServerMessageHandler or IClientMessageHandler - void* msgHandlerVTableFirstFunc = **(void****)(msg->m_pMessageHandler); - static auto engineBaseAddress = (uintptr_t)GetModuleHandleA("engine.dll"); - auto offset = uintptr_t(msgHandlerVTableFirstFunc) - engineBaseAddress; - - constexpr uintptr_t CLIENTSTATE_FIRST_VFUNC_OFFSET = 0x8A15C; - areWeServer = offset != CLIENTSTATE_FIRST_VFUNC_OFFSET; - } - - std::string BLOCK_PREFIX = std::string {"NET_SetConVar ("} + (areWeServer ? "server" : "client") + "): Blocked dangerous/invalid msg: "; - - if (areWeServer) - { - constexpr int SETCONVAR_SANITY_AMOUNT_LIMIT = 69; - if (msg->m_ConVars_count < 1 || msg->m_ConVars_count > SETCONVAR_SANITY_AMOUNT_LIMIT) - { - return BLOCKED_INFO("Invalid m_ConVars_count (" << msg->m_ConVars_count << ")"); - } - } - - for (int i = 0; i < msg->m_ConVars_count; i++) - { - auto entry = msg->m_ConVars + i; - - // Safety check for memory access - if (NSMem::IsMemoryReadable(entry, sizeof(*entry))) - { - - // Find null terminators - bool nameValid = false, valValid = false; - for (int i = 0; i < ENTRY_STR_LEN; i++) - { - if (!entry->name[i]) - nameValid = true; - if (!entry->val[i]) - valValid = true; - } - - if (!nameValid || !valValid) - return BLOCKED_INFO("Missing null terminators"); - - auto realVar = R2::g_pCVar->FindVar(entry->name); - - if (realVar) - memcpy( - entry->name, - realVar->m_ConCommandBase.m_pszName, - strlen(realVar->m_ConCommandBase.m_pszName) + 1); // Force name to match case - - bool isValidFlags = true; - if (areWeServer) - { - if (realVar) - isValidFlags = realVar->IsFlagSet(FCVAR_USERINFO); // ConVar MUST be userinfo var - } - else - { - // TODO: Should probably have some sanity checks, but can't find any that are consistent - } - - if (!isValidFlags) - { - if (!realVar) - { - return BLOCKED_INFO("Invalid flags on nonexistant cvar (how tho???)"); - } - else - { - return BLOCKED_INFO( - "Invalid flags (" << std::hex << "0x" << realVar->m_ConCommandBase.m_nFlags << "), var is " << entry->name); - } - } - } - else - { - return BLOCKED_INFO("Unreadable memory at " << (void*)entry); // Not risking that one, they all gotta be readable - } - } - - return oCClient_ProcessSetConVar(msg); -} - -// Purpose: prevent invalid user CMDs -KHOOK(CClient_ProcessUsercmds, ("engine.dll", "40 55 56 48 83 EC 58"), bool, __fastcall, (void* thisptr, void* pMsg)) -{ - struct CLC_Move - { - BYTE gap0[24]; - void* m_pMessageHandler; - int m_nBackupCommands; - int m_nNewCommands; - int m_nLength; - // bf_read m_DataIn; - // bf_write m_DataOut; - }; - - auto msg = (CLC_Move*)pMsg; - - const char* BLOCK_PREFIX = "ProcessUserCmds: "; - - if (msg->m_nBackupCommands < 0) - { - return BLOCKED_INFO("Invalid m_nBackupCommands (" << msg->m_nBackupCommands << ")"); - } - - if (msg->m_nNewCommands < 0) - { - return BLOCKED_INFO("Invalid m_nNewCommands (" << msg->m_nNewCommands << ")"); - } - - // removing, as vanilla already limits num usercmds per frame - /*constexpr int NUMCMD_SANITY_LIMIT = 16; - if ((msg->m_nNewCommands + msg->m_nBackupCommands) > NUMCMD_SANITY_LIMIT) - { - return BLOCKED_INFO("Command count is too high (new: " << msg->m_nNewCommands << ", backup: " << msg->m_nBackupCommands << ")"); - - }*/ - - if (msg->m_nLength <= 0) - return BLOCKED_INFO("Invalid message length (" << msg->m_nLength << ")"); - - return oCClient_ProcessUsercmds(thisptr, pMsg); -} - -KHOOK(ReadUsercmd, ("server.dll", "4C 89 44 24 ? 53 55 56 57"), void, __fastcall, (void* buf, void* pCmd_move, void* pCmd_from)) -{ - // Let normal usercmd read happen first, it's safe - oReadUsercmd(buf, pCmd_move, pCmd_from); - - // Now let's make sure the CMD we read isnt messed up to prevent numerous exploits (including server crashing) - struct __declspec(align(4)) SV_CUserCmd - { - DWORD command_number; - DWORD tick_count; - float command_time; - Angle worldViewAngles; - BYTE gap18[4]; - Angle localViewAngles; - Angle attackangles; - Vector move; - DWORD buttons; - BYTE impulse; - short weaponselect; - DWORD meleetarget; - BYTE gap4C[24]; - char headoffset; - BYTE gap65[11]; - Vector cameraPos; - Angle cameraAngles; - BYTE gap88[4]; - int tickSomething; - DWORD dword90; - DWORD predictedServerEventAck; - DWORD dword98; - float frameTime; - }; - - auto cmd = (SV_CUserCmd*)pCmd_move; - auto fromCmd = (SV_CUserCmd*)pCmd_from; - - std::string BLOCK_PREFIX = - "ReadUsercmd (command_number delta: " + std::to_string(cmd->command_number - fromCmd->command_number) + "): "; - - if (cmd->worldViewAngles.IsInvalid()) - { - BLOCKED_INFO("CMD has invalid worldViewAngles"); - goto INVALID_CMD; - } - - if (cmd->attackangles.IsInvalid()) - { - BLOCKED_INFO("CMD has invalid attackangles"); - goto INVALID_CMD; - } - - if (cmd->localViewAngles.IsInvalid()) - { - BLOCKED_INFO("CMD has invalid localViewAngles"); - goto INVALID_CMD; - } - - if (cmd->cameraAngles.IsInvalid()) - { - BLOCKED_INFO("CMD has invalid cameraAngles"); - goto INVALID_CMD; - } - - if (cmd->frameTime <= 0 || cmd->tick_count == 0 || cmd->command_time <= 0) - { - BLOCKED_INFO( - "Bogus cmd timing (tick_count: " << cmd->tick_count << ", frameTime: " << cmd->frameTime - << ", commandTime : " << cmd->command_time << ")"); - goto INVALID_CMD; // No simulation of bogus-timed cmds - } - - if (!cmd->move.IsValid()) - { - BLOCKED_INFO("Invalid move vector"); - goto INVALID_CMD; - } - - if (!cmd->cameraPos.IsValid()) - { - BLOCKED_INFO("Invalid cameraPos"); // IIRC this can crash spectating clients or anyone watching replays - goto INVALID_CMD; - } - - return; -INVALID_CMD: - - // Fix any gameplay-affecting cmd properties - // NOTE: Currently tickcount/frametime is set to 0, this ~shouldn't~ cause any problems - cmd->worldViewAngles = cmd->localViewAngles = cmd->attackangles = cmd->cameraAngles = Angle(0, 0, 0); - cmd->tick_count = cmd->frameTime = 0; - cmd->move = cmd->cameraPos = Vector(0, 0, 0); - cmd->buttons = 0; - cmd->meleetarget = 0; -} - -// basically: by default r2 isn't set as a valve mod, meaning that m_bRestrictServerCommands is false -// this is HORRIBLE for security, because it means servers can run arbitrary concommands on clients -// especially since we have script commands this could theoretically be awful -KHOOK(IsValveMod, ("engine.dll", "48 83 EC 28 48 8B 0D ? ? ? ? 48 8D 15 ? ? ? ? E8 ? ? ? ? 85 C0 74 63"), bool, __fastcall, ()) -{ - return !Tier0::CommandLine()->CheckParm("-norestrictservercommands"); -} - -// Fix respawn's crappy UTF8 parser so it doesn't crash -_- -// This also means you can launch multiplayer with "communities_enabled 1" and not crash, you're welcome -KHOOK( - CrashFunc_ParseUTF8, - ("engine.dll", "48 89 5C 24 ? 48 89 6C 24 ? 48 89 74 24 ? 57 41 54 41 55 41 56 41 57 48 83 EC 20 8B 1A"), - bool, - __fastcall, - (INT64 * a1, DWORD* a2, char* strData)) -{ - - static void* targetRetAddr = NSMem::PatternScan("engine.dll", "84 C0 75 2C 49 8B 16"); - - if (_ReturnAddress() == targetRetAddr) - { - if (!ExploitFixes_UTF8Parser::CheckValid(a1, a2, strData)) - { - const char* BLOCK_PREFIX = "ParseUTF8 Hook: "; - BLOCKED_INFO("Ignoring potentially-crashing utf8 string"); - return false; - } - } - - return oCrashFunc_ParseUTF8(a1, a2, strData); -} - -////////////////////////////////////////////////// - -void DoBytePatches() -{ - uintptr_t engineBase = (uintptr_t)GetModuleHandleA("engine.dll"); - uintptr_t serverBase = (uintptr_t)GetModuleHandleA("server.dll"); - - // patches to make commands run from client/ui script still work - // note: this is likely preventable in a nicer way? test prolly - NSMem::BytePatch(engineBase + 0x4FB65, "EB 11"); - NSMem::BytePatch(engineBase + 0x4FBAC, "EB 16"); - - { // Dumb ANTITAMPER patches (they negatively impact performance and security) - - constexpr const char* ANTITAMPER_EXPORTS[] = { - "ANTITAMPER_SPOTCHECK_CODEMARKER", - "ANTITAMPER_TESTVALUE_CODEMARKER", - "ANTITAMPER_TRIGGER_CODEMARKER", - }; - - // Prevent thesefrom actually doing anything - for (auto exportName : ANTITAMPER_EXPORTS) - { - - auto address = (uintptr_t)GetProcAddress(GetModuleHandleA("server.dll"), exportName); - if (!address) - { - spdlog::warn("Failed to find AntiTamper function export \"{}\"", exportName); - } - else - { - // Just return, none of them have any args or are userpurge - NSMem::BytePatch(address, "C3"); - spdlog::info("Patched AntiTamper function export \"{}\"", exportName); - } - } - } -} - -ON_DLL_LOAD_RELIESON("server.dll", ExploitFixes, ConVar, [](HMODULE baseAddress) -{ - spdlog::info("ExploitFixes::LoadCallback ..."); - - spdlog::info("\tByte patching..."); - DoBytePatches(); - - if (KHook::InitAllHooks()) - { - spdlog::info("\tInitialized " + std::to_string(KHook::_allHooks.size()) + " exploit-patch hooks."); - } - else - { - spdlog::critical("\tFAILED to initialize all exploit patches."); - - // Force exit? - MessageBoxA(0, "FAILED to initialize all exploit patches.", "Northstar", MB_ICONERROR); - exit(0); - } - - ns_exploitfixes_log = - new ConVar("ns_exploitfixes_log", "1", FCVAR_GAMEDLL, "Whether to log whenever ExploitFixes.cpp blocks/corrects something"); -})
\ No newline at end of file |