Initial commit.

linux/CMakeLists.txt

@@ -0,0 +1,18 @@
+cmake_minimum_required(VERSION 3.18)
+project(plexmediaserver_crack)
+SET(CMAKE_BUILD_RPATH_USE_ORIGIN TRUE)
+
+set(CMAKE_CXX_STANDARD 17)
+set(CMAKE_CXX_STANDARD_REQUIRED ON)
+set(CMAKE_CXX_EXTENSIONS OFF)
+add_compile_options(-Wall -Wextra -Werror)
+
+set(SOURCES main.cpp hook.cpp)
+set(HEADERS hook.hpp)
+
+add_library(plexmediaserver_crack SHARED ${SOURCES} ${HEADERS})
+set_target_properties(plexmediaserver_crack PROPERTIES PREFIX "")
+set_target_properties(plexmediaserver_crack PROPERTIES LINK_FLAGS "-static-libstdc++ -static-libgcc")
+set_target_properties(plexmediaserver_crack PROPERTIES OUTPUT_NAME "plexmediaserver_crack")
+target_link_libraries(plexmediaserver_crack PUBLIC rt)
+target_include_directories(plexmediaserver_crack PUBLIC ${CMAKE_CURRENT_SOURCE_DIR})

linux/hook.cpp

@@ -0,0 +1,122 @@
+#include "hook.hpp"
+
+#include <vector>
+#include <iostream>
+#include <fstream>
+#include <cstring>
+#include <sstream>
+#include <sys/mman.h>
+
+bool get_dottext_info(uintptr_t& start, uintptr_t& end)
+{
+	std::ifstream file("/proc/self/maps");
+	std::string line;
+	
+	while(std::getline(file, line))
+	{
+		// I don't understand Linux :|
+		// Only .text should have `r-xp`. This works I guess..
+		if(line.find("Plex Media Server") != std::string::npos && line.find("r-xp") != std::string::npos)
+		{
+			auto range = line.substr(0, line.find(' '));
+			start = std::stoull(line.substr(0, line.find('-')), nullptr, 16);
+			end = std::stoull(line.substr(line.find('-') + 1), nullptr, 16);
+
+			return true;
+		}
+	}
+
+	return false;
+}
+
+uintptr_t sig_scan(const uintptr_t start, const uintptr_t end, std::string_view pattern)
+{
+	constexpr const uint16_t WILDCARD = 0xFFFF;
+	std::vector<uint16_t> pattern_vec;
+	
+	for(uintptr_t i = 0; i < pattern.length(); i++)
+	{
+		if(pattern[i] == ' ')
+		{
+			continue;
+		}
+
+		if(pattern[i] == '?')
+		{
+			if(pattern[i + 1] == '?')
+			{
+				i++;
+			}
+
+			pattern_vec.push_back(WILDCARD);
+
+			continue;
+		}
+
+		pattern_vec.push_back(static_cast<uint16_t>(std::strtol(&pattern[i], nullptr, 16)));
+		i++;
+	}
+
+	const auto vec_length = pattern_vec.size();
+
+	for(uintptr_t i = start; i < end; i++)
+	{
+		for(uintptr_t x = 0; x < vec_length; x++)
+		{
+			const auto mem = *reinterpret_cast<uint8_t*>(i + x);
+
+			if(pattern_vec[x] != WILDCARD && mem != pattern_vec[x])
+			{
+				break;
+			}
+
+			else if(x == vec_length - 1)
+			{
+				return i;
+			}
+		}
+	}
+
+	return 0;
+}
+
+uint64_t hook_is_feature_available([[maybe_unused]] uintptr_t user, [[maybe_unused]] const char* feature)
+{
+	// `feature` is a GUID. You can use it to enable certain features rather than Godmode (everything); but there's no reason to limit ourselves.. is there?
+
+	return true;
+}
+
+void hook()
+{
+	uintptr_t dottext_start;
+	uintptr_t dottext_end;
+	
+	if(!get_dottext_info(dottext_start, dottext_end))
+	{
+		return;
+	}
+
+	const auto _is_feature_available = sig_scan(dottext_start, dottext_end, "55 48 89 E5 41 57 41 56 53 50 49 89 F7 48 89 FB 4C 8D 77 08 4C 89 F7 E8 ? ? ? ? 48 8D 7B 30");
+
+	if(_is_feature_available == 0)
+	{
+		return;
+	}
+
+	// Jumps to specified address
+	uint8_t shellcode[] =
+	{
+		0x48, 0xB8, // movq rax, ?
+		0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+
+		0x50, // push rax
+		0xC3  // ret
+	};
+
+	*reinterpret_cast<decltype(&hook_is_feature_available)*>(&shellcode[2]) = &hook_is_feature_available;
+
+	mprotect(reinterpret_cast<void*>(_is_feature_available), sizeof(shellcode), PROT_READ|PROT_WRITE|PROT_EXEC);
+	memcpy(reinterpret_cast<void*>(_is_feature_available), shellcode, sizeof(shellcode));
+	mprotect(reinterpret_cast<void*>(_is_feature_available), sizeof(shellcode), PROT_READ|PROT_EXEC);
+}

linux/hook.hpp

@@ -0,0 +1,9 @@
+#pragma once
+
+#include <cstdint>
+#include <string>
+
+bool get_dottext_info(uintptr_t& start, uintptr_t& end);
+uintptr_t sig_scan(const uintptr_t start, const uintptr_t end, std::string_view pattern);
+uint64_t hook_is_feature_available(uintptr_t user, const char* feature);
+void hook();

linux/main.cpp

@@ -0,0 +1,6 @@
+#include "hook.hpp"
+
+__attribute__((constructor)) void init_so()
+{
+    hook();
+}