save player data based on username

mcpe/ExtendedCertificate.h

@@ -0,0 +1,7 @@
+#pragma once
+
+class ExtendedCertificate {
+
+public:
+    static mcpe::string (*ExtendedCertificate_getXuid)(ExtendedCertificate*);
+};

mcpe/UUID.h

@@ -1,14 +1,51 @@
 #pragma once
 
+#include <cstdint>
+#include <iomanip>
+#include <sstream>
+#include <string>
+
+namespace {
+
+inline uint64_t fnv1a_64(const std::string& s) {
+    uint64_t hash = 14695981039346656037ULL;
+    for (unsigned char c : s) {
+        hash ^= c;
+        hash *= 1099511628211ULL;
+    }
+    return hash;
+}
+
+}
+
 namespace mce {
 
 class UUID {
 
 public:
-
     static UUID* EMPTY;
+    static mce::UUID (*fromString)(mcpe::string const&);
+
     char filler[0x14];
 
+    static inline mce::UUID fromText(const std::string& text) {
+        uint64_t h1 = fnv1a_64(text);
+        uint64_t h2 = fnv1a_64("salt:" + text);
+
+        uint16_t version = ((h1 >> 16) & 0x0FFF) | 0x5000; // v5
+        uint16_t variant = ((h2 >> 48) & 0x3FFF) | 0x8000;
+
+        std::ostringstream oss;
+        oss << std::hex << std::setfill('0')
+            << std::setw(8) << (uint32_t)(h1 >> 32) << "-"
+            << std::setw(4) << (uint16_t)(h1 >> 16) << "-"
+            << std::setw(4) << version << "-"
+            << std::setw(4) << variant << "-"
+            << std::setw(12) << (h2 & 0xFFFFFFFFFFFFULL);
+
+        mcpe::string uuidStr(oss.str().c_str());
+        return fromString(uuidStr);
+    }
 };
 
 }

mcpe/types.cpp

@@ -127,6 +127,7 @@ void (*ServerInstance::ServerInstance_update)(ServerInstance*);
 #include "UUID.h"
 
 mce::UUID* mce::UUID::EMPTY;
+mce::UUID (*mce::UUID::fromString)(mcpe::string const&);
 
 #include "ResourcePackStack.h"
 
@@ -149,3 +150,7 @@ MCRESULT (*MinecraftCommands::MinecraftCommands_requestCommandExecution)(Minecra
 #include "DedicatedServerCommandOrigin.h"
 
 void (*DedicatedServerCommandOrigin::DedicatedServerCommandOrigin_construct)(DedicatedServerCommandOrigin*, mcpe::string const&, Minecraft&);
+
+#include "ExtendedCertificate.h"
+
+mcpe::string (*ExtendedCertificate::ExtendedCertificate_getXuid)(ExtendedCertificate*);

src/server.cpp

@@ -31,6 +31,7 @@
 #include "../mcpe/UUID.h"
 #include "../mcpe/ResourcePackStack.h"
 #include "../mcpe/Scheduler.h"
+#include "../mcpe/ExtendedCertificate.h"
 
 extern "C" {
 
@@ -40,8 +41,6 @@ extern "C" {
 
 }
 
-MinecraftEventing* g_eventingInstance = nullptr;
-
 void stubFunc() {}
 
 void detachFromJavaStub() {
@@ -65,6 +64,11 @@ void handleTextPacketStub() {
     std::cout << "chat message\n";
 }
 
+mce::UUID getIdentityStub(ExtendedCertificate* cert) {
+    mcpe::string xuid = ExtendedCertificate::ExtendedCertificate_getXuid(cert);
+    return mce::UUID::fromText(std::string(xuid.c_str()));
+}
+
 using namespace std;
 
 int main(int argc, char *argv[]) {
@@ -145,6 +149,15 @@ int main(int argc, char *argv[]) {
     patchOff = (unsigned int) hybris_dlsym(handle, "_ZN20ServerNetworkHandler6handleERK17NetworkIdentifierRK10TextPacket");
     patchCallInstruction((void*) patchOff, (void*) &handleTextPacketStub, true);
 
+    // murdle: this is a patch to make player data save via your username
+    // this makes it easy to just switch devices and have the same inventory and position
+
+    bool onlineMode = ServerProperties::instance().getBool("online-mode", false);
+    if (!onlineMode) {
+        patchOff = (unsigned int) hybris_dlsym(handle, "_ZN19ExtendedCertificate11getIdentityERK11Certificate");
+        patchCallInstruction((void*) patchOff, (void*) &getIdentityStub, true);
+    }
+
     mcpe::string::empty = (mcpe::string*) hybris_dlsym(handle, "_ZN4Util12EMPTY_STRINGE");
 
     std::cout << "patches applied!\n";
@@ -161,6 +174,7 @@ int main(int argc, char *argv[]) {
 
     // server functions
     ((void*&) mce::UUID::EMPTY) = hybris_dlsym(handle, "_ZN3mce4UUID5EMPTYE");    
+    ((void*&) mce::UUID::fromString) = hybris_dlsym(handle, "_ZN3mce4UUID10fromStringERKSs");    
 
     ((void*&) FilePathManager::FilePathManager_construct) = hybris_dlsym(handle, "_ZN15FilePathManagerC2ESsb");
     ((void*&) FilePathManager::FilePathManager_getRootPath) = hybris_dlsym(handle, "_ZNK15FilePathManager11getRootPathEv");
@@ -173,6 +187,7 @@ int main(int argc, char *argv[]) {
     ((void*&) Social::XboxLiveUserManager::XboxLiveUserManager_construct) = hybris_dlsym(handle, "_ZN6Social19XboxLiveUserManagerC2ER11ScreenStack");
     ((void*&) Social::UserManager::UserManager_construct) = hybris_dlsym(handle, "_ZN6Social11UserManagerC2Ev");
     ((void*&) Social::UserManager::UserManager_addUser) = hybris_dlsym(handle, "_ZN6Social11UserManager7addUserESt10unique_ptrINS_19XboxLiveUserManagerESt14default_deleteIS2_EEi");
+    ((void*&) ExtendedCertificate::ExtendedCertificate_getXuid) = hybris_dlsym(handle, "_ZN19ExtendedCertificate7getXuidERK11Certificate");    
 
     ((void*&) MinecraftEventing::MinecraftEventing_construct) = hybris_dlsym(handle, "_ZN17MinecraftEventingC2ERKSs");
     ((void*&) EntitlementManager::EntitlementManager_construct) = hybris_dlsym(handle, "_ZN18EntitlementManagerC2ER17MinecraftEventingRN6Social11UserManagerE");
@@ -284,7 +299,7 @@ int main(int argc, char *argv[]) {
         ServerProperties::instance().getInt("server-port", 19132),
         ServerProperties::instance().getInt("server-port-v6", 19133),
         ServerProperties::instance().getInt("max-players", 20),
-        ServerProperties::instance().getBool("online-mode", false),
+        onlineMode,
         {},
         "normal",
         false,