Update year

ATTRIBUTIONS.md

@@ -3,7 +3,7 @@
 ## ASIO C++ Library
 - **Name:** ASIO (standalone)
 - **Website:** https://think-async.com/Asio/
-- **Copyright:** (c) 2003-2025 Christopher M. Kohlhoff
+- **Copyright:** (c) 2003-2026 Christopher M. Kohlhoff
 - **License:** Boost Software License, Version 1.0
 - **License Text:** See `third_party/asio/LICENSE_1_0.txt`
 
@@ -12,14 +12,14 @@ This project uses the standalone version of the ASIO C++ library for asynchronou
 ## CXXOPTS C++ Library
 - **Name:** cxxopts
 - **Website:** https://github.com/jarro2783/cxxopts/
-- **Copyright:** (c) 2014-2025 Christopher M. Kohlhoff
+- **Copyright:** (c) 2014-2026 Christopher M. Kohlhoff
 - **License:** MIT License
 - **License Text:** See `third_party/cxxopts/LICENSE_1_0.txt`
 
 ## Wintun C++ Library
 - **Name:** wintun
 - **Website:** https://www.wintun.net/
-- **Copyright:** (c) 2018-2025 WireGuard LLC
+- **Copyright:** (c) 2018-2026 WireGuard LLC
 - **License:** MIT License OR GPL-2.0 License
 - **License Text:** See `third_party/wintun/`
 - **Utilized Under:** MIT License

CMakeLists.txt

@@ -6,7 +6,7 @@ cmake_minimum_required(VERSION 3.16)
 # If MAJOR is 0, and MINOR > 0, Version is BETA
 
 project(ColumnLynx
-    VERSION 0.3.0
+    VERSION 1.0.1
     LANGUAGES CXX
 )
 
@@ -50,7 +50,7 @@ endif()
 FetchContent_Declare(
     Sodium
     GIT_REPOSITORY https://github.com/robinlinden/libsodium-cmake.git
-    GIT_TAG e5b985ad0dd235d8c4307ea3a385b45e76c74c6a  # Last updated at 2025-04-13
+    GIT_TAG e5b985ad0dd235d8c4307ea3a385b45e76c74c6a
 )
 
 set(SODIUM_DISABLE_TESTS ON CACHE BOOL "" FORCE)

README.md

@@ -18,22 +18,155 @@ This simplicity-focused design approach allows us to make an efficient, low-over
 
 ## Configuration
 
-Configurating the server and client are are relatively easy. Currently (since the project is in alpha), the configuration files **must be in the same directory as the working directory**.
+Configurating the server and client are are relatively easy. Currently (since the project is in alpha), the configuration files **must be in your system-specific config location** (which can be overriden via a CLI argument or the **COLUMNLYNX_CONFIG_DIR** Environment Variable).
+
+The defaults depends on your system.
+
+For the server:
+- Linux: **/etc/columnlynx**
+- macOS: **/etc/columnlynx**
+- Windows: **C:\ProgramData\ColumnLynx**
+
+For the client:
+- Linux: **~/.config/columnlynx**
+- macOS: **~/Library/Application Support/columnlynx**
+- Windows: **C:\Users\USERNAME\AppData\Local\ColumnLynx**
+
+### Getting a keypair
+
+Release builds of the software force you to specify your own keypairs. That's why you need to generate a keypair with some other software that you can use.
+
+This guide will show a generation example with openssl:
+
+#### Generate a keypair:
+```bash
+openssl genpkey -algorithm ED25519 -out key.pem
+```
+
+#### Extract the **Private Key Seed**:
+```bash
+openssl pkey -in key.pem -outform DER | tail -c 32 | xxd -p -c 32
+# Output example: 9f3a2b6c0f8e4d1a7c3e9a4b5d2f8c6e1a9d0b7e3f4c2a8e6d5b1f0a3c4e
+```
+
+#### Extract the **Raw Public Key**:
+```bash
+openssl pkey -in key.pem -pubout -outform DER | tail -c 32 | xxd -p -c 32
+# Output example: 1c9d4f7a3b2e8a6d0f5c9b1e4d8a7f3c6e2b1a9d5f4c8e0a7b3d6c9f2e
+```
+
+You can then set these keys accordingly in the **server_config** and **client_config** files.
+
+### Server Setup (Linux Server ONLY)
+
+#### Creating the Tun Interface
+
+In order for the VPN server to work, you need to create the Tun interface that the VPN will use.
+
+This is the set of commands to create one on Linux. Replace the example 10.10.0.1/24 IPv4 address with the FIRST IPv4 in the Network and Subnet Mask that you set in server_config.
+```bash
+sudo ip tuntap add dev lynx0 mode tun
+sudo ip addr add 10.10.0.1/24 dev lynx0
+sudo ip link set dev lynx0 mtu 1420
+sudo ip link set dev lynx0 up
+```
+
+#### Creating the systemd service
+
+It is highly recommended to **run the server as a systemd service**, as systemd is the primary service manager on Linux.
+
+**1. Create a file for the service**
+```bash
+sudo touch /etc/systemd/system/columnlynx.service
+```
+
+**2. Open the file in your editor of choice**
+```bash
+sudo nano /etc/systemd/system/columnlynx.service
+# OR
+sudo vim /etc/systemd/system/columnlynx.service
+# OR any other editor of your choice...
+```
+
+**3. Configure the service**
+
+**Replace** the **ExecStart** and **WorkingDirectory** paths with the paths where your binaries are stored.
+
+If you configured your tun interface to belong to a custom user, you may also replace the **User** and **Group** with that user, however you must ensure that that user owns the **tun interface**, **config directory in /etc/columnlynx** and the **working directory**.
+
+This is a **simple example** for the **root user** and the executable in **/opt/columnlynx**:
+
+```
+[Unit]
+Description=ColumnLynx Server Service
+After=network.target
+
+[Service]
+Type=simple
+ExecStart=/opt/columnlynx/columnlynx_server
+WorkingDirectory=/opt/columnlynx
+User=root
+Group=root
+Restart=on-failure
+StandardOutput=append:/var/log/columnlynx.log
+StandardError=append:/var/log/columnlynx.err
+
+[Install]
+WantedBy=multi-user.target
+```
+
+**4. Reload systemd and enable the service**
+
+```bash
+sudo systemctl daemon-reload
+sudo systemctl enable columnlynx.service
+sudo systemctl start columnlynx.service
+```
+
+#### Set firewall rules
+
+This part greatly depends on your firewall of choice. Generally you just need to **allow port 48042 on both TCP and UDP** (Both IPv4 and IPv6).
+
+This example is for **UFW**:
+
+```bash
+sudo ufw allow 48042
+sudo ufw reload
+```
+
+
+#### IPTables rules for forwarding (Optional)
+
+In addition to creating the interface, you'll also need to make some **iptables** rules if you want to be able to **send traffic to foreign networks** (more like a *commercial VPN*).
+
+You can do these as such (example with NFT IPTABLES):
+
+- Enable the **generic IPv4 forwarding**:
+```bash
+sudo sysctl net.ipv4.ip_forward=1
+```
+- Create the masquerade (**Replace the IP subnet** with your own that you set in the config and **replace the interface** with your server's main (NOT *lynx0*) interface):
+```bash
+sudo nft add table nat
+sudo nft add chain nat postroute { type nat hook postrouting priority 100 \; }
+sudo nft add rule nat postroute ip saddr 10.10.0.0/24 oifname "eth0" masquerade
+```
+
 
 ### Server
  
 "**server_config**" is a file that contains the server configuration, **one variable per line**. These are the current configuration available variables:
 
-- **SERVER_PUBLIC_KEY** (Hex String): The public key to be used
-- **SERVER_PRIVATE_KEY** (Hex String): The private key to be used
+- **SERVER_PUBLIC_KEY** (Hex String): The public key to be used - Used for verification
+- **SERVER_PRIVATE_KEY** (Hex String): The private key seed to be used
 - **NETWORK** (IPv4 Format): The network IPv4 to be used (Server Interface still needs to be configured manually)
 - **SUBNET_MASK** (Integer): The subnet mask to be used (ensure proper length, it will not be checked)
 
 **Example:**
 
 ```
-SERVER_PUBLIC_KEY=787B648046F10DDD0B77A6303BE42D859AA65C52F5708CC3C58EB5691F217C7B
-SERVER_PRIVATE_KEY=778604245F57B847E63BD85DE8208FF1A127FB559895195928C3987E246B77B8787B648046F10DDD0B77A6303BE42D859AA65C52F5708CC3C58EB5691F217C7B
+SERVER_PUBLIC_KEY=1c9d4f7a3b2e8a6d0f5c9b1e4d8a7f3c6e2b1a9d5f4c8e0a7b3d6c9f2e
+SERVER_PRIVATE_KEY=9f3a2b6c0f8e4d1a7c3e9a4b5d2f8c6e1a9d0b7e3f4c2a8e6d5b1f0a3c4e
 NETWORK=10.10.0.0
 SUBNET_MASK=24
 ```
@@ -53,14 +186,14 @@ SUBNET_MASK=24
  
 "**client_config**" is a file that contains the client configuration, **one variable per line**. These are the current configuration available variables:
 
-- **CLIENT_PUBLIC_KEY** (Hex String): The public key to be used
-- **CLIENT_PRIVATE_KEY** (Hex String): The private key to be used
+- **CLIENT_PUBLIC_KEY** (Hex String): The public key to be used - Used for verification
+- **CLIENT_PRIVATE_KEY** (Hex String): The private key seed to be used
 
 **Example:**
 
 ```
-CLIENT_PUBLIC_KEY=8CC8BE1A9D24639D0492EF143E84E2BD4C757C9B3B687E7035173EBFCA8FEDDA
-CLIENT_PRIVATE_KEY=9B486A5B1509FA216F9EEFED85CACF2384E9D902A76CC979BFA143C18B869F5C8CC8BE1A9D24639D0492EF143E84E2BD4C757C9B3B687E7035173EBFCA8FEDDA
+CLIENT_PUBLIC_KEY=1c9d4f7a3b2e8a6d0f5c9b1e4d8a7f3c6e2b1a9d5f4c8e0a7b3d6c9f2e
+CLIENT_PRIVATE_KEY=9f3a2b6c0f8e4d1a7c3e9a4b5d2f8c6e1a9d0b7e3f4c2a8e6d5b1f0a3c4e
 ```
 
 <hr></hr>

include/columnlynx/client/net/tcp/tcp_client.hpp

@@ -1,5 +1,5 @@
 // tcp_client.hpp - TCP Client for ColumnLynx
-// Copyright (C) 2025 DcruBro
+// Copyright (C) 2026 DcruBro
 // Distributed under the terms of the GNU General Public License, either version 2 only or version 3. See LICENSES/ for details.
 
 #pragma once
@@ -14,6 +14,7 @@
 #include <algorithm>
 #include <vector>
 #include <unordered_map>
+#include <string>
 #include <columnlynx/common/net/protocol_structs.hpp>
 #include <columnlynx/common/net/virtual_interface.hpp>
 
@@ -29,6 +30,7 @@ namespace ColumnLynx::Net::TCP {
                       std::shared_ptr<std::array<uint8_t, 32>> aesKey,
                       std::shared_ptr<uint64_t> sessionIDRef,
                       bool insecureMode,
+                      std::string& configPath,
                       std::shared_ptr<VirtualInterface> tun = nullptr)
                 :
                 mResolver(ioContext),
@@ -42,10 +44,11 @@ namespace ColumnLynx::Net::TCP {
                 mHeartbeatTimer(mSocket.get_executor()),
                 mLastHeartbeatReceived(std::chrono::steady_clock::now()),
                 mLastHeartbeatSent(std::chrono::steady_clock::now()),
-                mTun(tun)
+                mTun(tun),
+                mConfigDirPath(configPath)
             {
                 // Preload the config map
-                mRawClientConfig = Utils::getConfigMap("client_config");
+                mRawClientConfig = Utils::getConfigMap(configPath + "client_config");
 
                 auto itPubkey = mRawClientConfig.find("CLIENT_PUBLIC_KEY");
                 auto itPrivkey = mRawClientConfig.find("CLIENT_PRIVATE_KEY");
@@ -54,16 +57,22 @@ namespace ColumnLynx::Net::TCP {
                     Utils::log("Loading keypair from config file.");
                 
                     PublicKey pk;
-                    PrivateKey sk;
+                    PrivateSeed seed;
                 
-                    std::copy_n(Utils::hexStringToBytes(itPrivkey->second).begin(), sk.size(), sk.begin()); // This is extremely stupid, but the C++ compiler has forced my hand (I would've just used to_array, but fucking asio decls)
+                    std::copy_n(Utils::hexStringToBytes(itPrivkey->second).begin(), seed.size(), seed.begin()); // This is extremely stupid, but the C++ compiler has forced my hand (I would've just used to_array, but fucking asio decls)
                     std::copy_n(Utils::hexStringToBytes(itPubkey->second).begin(), pk.size(), pk.begin());
                 
-                    mLibSodiumWrapper->setKeys(pk, sk);
+                    if (!mLibSodiumWrapper->recomputeKeys(seed, pk)) {
+                        throw std::runtime_error("Failed to recompute keypair from config file values!");
+                    }
 
                     Utils::debug("Newly-Loaded Public Key: " + Utils::bytesToHexString(mLibSodiumWrapper->getPublicKey(), 32));
                 } else {
+                    #if defined(DEBUG)
                     Utils::warn("No keypair found in config file! Using random key.");
+                    #else
+                    throw std::runtime_error("No keypair found in config file! Cannot start client without keys.");
+                    #endif
                 }
             }
 
@@ -109,5 +118,6 @@ namespace ColumnLynx::Net::TCP {
             Protocol::TunConfig mTunConfig;
             std::shared_ptr<VirtualInterface> mTun = nullptr;
             std::unordered_map<std::string, std::string> mRawClientConfig;
+            std::string mConfigDirPath;
     };
 }

include/columnlynx/client/net/udp/udp_client.hpp

@@ -1,5 +1,5 @@
 // udp_client.hpp - UDP Client for ColumnLynx
-// Copyright (C) 2025 DcruBro
+// Copyright (C) 2026 DcruBro
 // Distributed under the terms of the GNU General Public License, either version 2 only or version 3. See LICENSES/ for details.
 
 #pragma once

include/columnlynx/common/libsodium_wrapper.hpp

@@ -1,5 +1,5 @@
 // libsodium_wrapper.hpp - Libsodium Wrapper for ColumnLynx
-// Copyright (C) 2025 DcruBro
+// Copyright (C) 2026 DcruBro
 // Distributed under the terms of the GNU General Public License, either version 2 only or version 3. See LICENSES/ for details.
 
 #pragma once
@@ -17,6 +17,7 @@
 namespace ColumnLynx {
     using PublicKey = std::array<uint8_t, crypto_sign_PUBLICKEYBYTES>;   // Ed25519
     using PrivateKey = std::array<uint8_t, crypto_sign_SECRETKEYBYTES>;   // Ed25519
+    using PrivateSeed = std::array<uint8_t, crypto_sign_SEEDBYTES>;       // 32 bytes
     using Signature = std::array<uint8_t, crypto_sign_BYTES>;            // 64 bytes
     using SymmetricKey = std::array<uint8_t, crypto_aead_chacha20poly1305_ietf_KEYBYTES>; // 32 bytes
     using Nonce = std::array<uint8_t, crypto_aead_chacha20poly1305_ietf_NPUBBYTES>;       // 12 bytes
@@ -53,6 +54,9 @@ namespace ColumnLynx::Utils {
                 }
             }
 
+            // Recompute the keypair from a given private seed; Will return false on failure
+            bool recomputeKeys(PrivateSeed privateSeed, PublicKey storedPubKey);
+
             // Helper section
 
             // Generates a random 256-bit (32-byte) array

include/columnlynx/common/net/protocol_structs.hpp

@@ -1,5 +1,5 @@
 // protocol_structs.hpp - Network Protocol Structures
-// Copyright (C) 2025 DcruBro
+// Copyright (C) 2026 DcruBro
 // Distributed under the terms of the GNU General Public License, either version 2 only or version 3. See LICENSES/ for details.
 
 #pragma once

include/columnlynx/common/net/session_registry.hpp

@@ -1,5 +1,5 @@
 // session_registry.hpp - Session Registry for ColumnLynx
-// Copyright (C) 2025 DcruBro
+// Copyright (C) 2026 DcruBro
 // Distributed under the terms of the GNU General Public License, either version 2 only or version 3. See LICENSES/ for details.
 
 #pragma once

include/columnlynx/common/net/tcp/net_helper.hpp

@@ -1,5 +1,5 @@
 // net_helper.hpp - Network Helper Functions for ColumnLynx
-// Copyright (C) 2025 DcruBro
+// Copyright (C) 2026 DcruBro
 // Distributed under the terms of the GNU General Public License, either version 2 only or version 3. See LICENSES/ for details.
 
 #pragma once

include/columnlynx/common/net/tcp/tcp_message_handler.hpp

@@ -1,5 +1,5 @@
 // tcp_message_handler.hpp - TCP Message Handler for ColumnLynx
-// Copyright (C) 2025 DcruBro
+// Copyright (C) 2026 DcruBro
 // Distributed under the terms of the GNU General Public License, either version 2 only or version 3. See LICENSES/ for details.
 
 #pragma once

include/columnlynx/common/net/tcp/tcp_message_type.hpp

@@ -1,5 +1,5 @@
 // tcp_message_type.hpp - TCP Message Types for ColumnLynx
-// Copyright (C) 2025 DcruBro
+// Copyright (C) 2026 DcruBro
 // Distributed under the terms of the GNU General Public License, either version 2 only or version 3. See LICENSES/ for details.
 
 #pragma once

include/columnlynx/common/net/udp/udp_message_type.hpp

@@ -1,5 +1,5 @@
 // udp_message_type.hpp - UDP Message Types for ColumnLynx
-// Copyright (C) 2025 DcruBro
+// Copyright (C) 2026 DcruBro
 // Distributed under the terms of the GNU General Public License, either version 2 only or version 3. See LICENSES/ for details.
 
 #pragma once

include/columnlynx/common/net/virtual_interface.hpp

@@ -1,5 +1,5 @@
 // virtual_interface.hpp - Virtual Interface for Network Communication
-// Copyright (C) 2025 DcruBro
+// Copyright (C) 2026 DcruBro
 // Distributed under the terms of the GNU General Public License, either version 2 only or version 3. See LICENSES/ for details.
 
 #pragma once
@@ -36,6 +36,12 @@
     #include <locale>
     #include <codecvt>
     #include <wintun/wintun.h>
+
+    #include <iphlpapi.h>
+    #include <netioapi.h>
+    
+    #pragma comment(lib, "iphlpapi.lib")
+    #pragma comment(lib, "ws2_32.lib")
 #endif
 
 namespace ColumnLynx::Net {

include/columnlynx/common/panic_handler.hpp

@@ -1,5 +1,5 @@
 // panic_handler.hpp - Panic Handler for ColumnLynx
-// Copyright (C) 2025 DcruBro
+// Copyright (C) 2026 DcruBro
 // Distributed under the terms of the GNU General Public License, either version 2 only or version 3. See LICENSES/ for details.
 
 #pragma once

include/columnlynx/common/utils.hpp

@@ -1,5 +1,5 @@
 // utils.hpp - Utility functions for ColumnLynx
-// Copyright (C) 2025 DcruBro
+// Copyright (C) 2026 DcruBro
 // Distributed under the terms of the GNU General Public License, either version 2 only or version 3. See LICENSES/ for details.
 
 #pragma once
@@ -29,6 +29,9 @@ namespace ColumnLynx {
 }
 
 namespace ColumnLynx::Utils {
+    // Converts unix milliseconds to a local ISO 8601 formatted string; Defaults to local time; Will use UTC if local is false.
+    std::string unixMillisToISO8601(uint64_t unixMillis, bool local = true);
+
     // General log function. Use for logging important information.
     void log(const std::string &msg);
     // General warning function. Use for logging important warnings.
@@ -44,7 +47,7 @@ namespace ColumnLynx::Utils {
     std::string getVersion();
     unsigned short serverPort();
     unsigned char protocolVersion();
-    std::vector<std::string> getWhitelistedKeys();
+    std::vector<std::string> getWhitelistedKeys(std::string basePath);
 
     // Raw byte to hex string conversion helper
     std::string bytesToHexString(const uint8_t* bytes, size_t length);

include/columnlynx/server/net/tcp/tcp_connection.hpp

@@ -1,5 +1,5 @@
 // tcp_connection.hpp - TCP Connection for ColumnLynx
-// Copyright (C) 2025 DcruBro
+// Copyright (C) 2026 DcruBro
 // Distributed under the terms of the GNU General Public License, either version 2 only or version 3. See LICENSES/ for details.
 
 #pragma once
@@ -28,9 +28,10 @@ namespace ColumnLynx::Net::TCP {
                 asio::ip::tcp::socket socket,
                 std::shared_ptr<Utils::LibSodiumWrapper> sodiumWrapper,
                 std::unordered_map<std::string, std::string>* serverConfig,
+                std::string configDirPath,
                 std::function<void(pointer)> onDisconnect)
             {
-                auto conn = pointer(new TCPConnection(std::move(socket), sodiumWrapper, serverConfig));
+                auto conn = pointer(new TCPConnection(std::move(socket), sodiumWrapper, serverConfig, configDirPath));
                 conn->mOnDisconnect = std::move(onDisconnect);
                 return conn;
             }
@@ -50,14 +51,15 @@ namespace ColumnLynx::Net::TCP {
             std::array<uint8_t, 32> getAESKey() const;
         
         private:
-            TCPConnection(asio::ip::tcp::socket socket, std::shared_ptr<Utils::LibSodiumWrapper> sodiumWrapper, std::unordered_map<std::string, std::string>* serverConfig)
+            TCPConnection(asio::ip::tcp::socket socket, std::shared_ptr<Utils::LibSodiumWrapper> sodiumWrapper, std::unordered_map<std::string, std::string>* serverConfig, std::string configDirPath)
                 :
                 mHandler(std::make_shared<MessageHandler>(std::move(socket))),
                 mLibSodiumWrapper(sodiumWrapper),
                 mRawServerConfig(serverConfig),
                 mHeartbeatTimer(mHandler->socket().get_executor()),
                 mLastHeartbeatReceived(std::chrono::steady_clock::now()),
-                mLastHeartbeatSent(std::chrono::steady_clock::now())
+                mLastHeartbeatSent(std::chrono::steady_clock::now()),
+                mConfigDirPath(configDirPath)
             {}
 
             // Start the heartbeat routine
@@ -77,5 +79,6 @@ namespace ColumnLynx::Net::TCP {
             std::chrono::steady_clock::time_point mLastHeartbeatSent;
             int mMissedHeartbeats = 0;
             std::string mRemoteIP; // Cached remote IP to avoid calling remote_endpoint() on closed sockets
+            std::string mConfigDirPath;
     };
 }

include/columnlynx/server/net/tcp/tcp_server.hpp

@@ -1,5 +1,5 @@
 // tcp_server.hpp - TCP Server for ColumnLynx
-// Copyright (C) 2025 DcruBro
+// Copyright (C) 2026 DcruBro
 // Distributed under the terms of the GNU General Public License, either version 2 only or version 3. See LICENSES/ for details.
 
 #pragma once
@@ -25,14 +25,17 @@ namespace ColumnLynx::Net::TCP {
             TCPServer(asio::io_context& ioContext,
                       uint16_t port,
                       std::shared_ptr<Utils::LibSodiumWrapper> sodiumWrapper,
-                      std::shared_ptr<bool> hostRunning, bool ipv4Only = false)
+                      std::shared_ptr<bool> hostRunning,
+                      std::string& configPath,
+                      bool ipv4Only = false)
                 : mIoContext(ioContext),
                   mAcceptor(ioContext),
                   mSodiumWrapper(sodiumWrapper),
-                  mHostRunning(hostRunning)
+                  mHostRunning(hostRunning),
+                  mConfigDirPath(configPath)
             {
                 // Preload the config map
-                mRawServerConfig = Utils::getConfigMap("server_config", {"NETWORK", "SUBNET_MASK"});
+                mRawServerConfig = Utils::getConfigMap(configPath + "server_config", {"NETWORK", "SUBNET_MASK"});
 
                 asio::error_code ec_open, ec_v6only, ec_bind;
 
@@ -84,6 +87,7 @@ namespace ColumnLynx::Net::TCP {
             std::shared_ptr<Utils::LibSodiumWrapper> mSodiumWrapper;
             std::shared_ptr<bool> mHostRunning;
             std::unordered_map<std::string, std::string> mRawServerConfig;
+            std::string mConfigDirPath;
     };
 
 }

include/columnlynx/server/net/udp/udp_server.hpp

@@ -1,5 +1,5 @@
 // udp_server.hpp - UDP Server for ColumnLynx
-// Copyright (C) 2025 DcruBro
+// Copyright (C) 2026 DcruBro
 // Distributed under the terms of the GNU General Public License, either version 2 only or version 3. See LICENSES/ for details.
 
 #pragma once

src/client/main.cpp

@@ -1,5 +1,5 @@
 // main.cpp - Client entry point for ColumnLynx
-// Copyright (C) 2025 DcruBro
+// Copyright (C) 2026 DcruBro
 // Distributed under the terms of the GNU General Public License, either version 2 only or version 3. See LICENSES/ for details.
 
 #include <asio.hpp>
@@ -12,6 +12,10 @@
 #include <cxxopts.hpp>
 #include <columnlynx/common/net/virtual_interface.hpp>
 
+#if defined(__WIN32__)
+#include <windows.h>
+#endif
+
 using asio::ip::tcp;
 using namespace ColumnLynx::Utils;
 using namespace ColumnLynx::Net;
@@ -48,15 +52,23 @@ int main(int argc, char** argv) {
 #else
         ("i,interface", "Override used interface", cxxopts::value<std::string>()->default_value("lynx0"))
 #endif
-        ("allow-selfsigned", "Allow self-signed certificates", cxxopts::value<bool>()->default_value("false"));
+        ("ignore-whitelist", "Ignore if server is not in whitelisted_keys", cxxopts::value<bool>()->default_value("false"))
+#if defined(__WIN32__)
+/* Get config dir in LOCALAPPDATA\ColumnLynx\ */
+        ("config-dir", "Override config dir path", cxxopts::value<std::string>()->default_value(std::string((std::getenv("LOCALAPPDATA") ? std::getenv("LOCALAPPDATA") : "C:\\ProgramData")) + "\\ColumnLynx\\"));
+#elif defined(__APPLE__)
+        ("config-dir", "Override config dir path", cxxopts::value<std::string>()->default_value(std::string((std::getenv("HOME") ? std::getenv("HOME") : "")) + "/Library/Application Support/ColumnLynx/"));
+#else
+        ("config-dir", "Override config dir path", cxxopts::value<std::string>()->default_value(std::string((std::getenv("SUDO_USER") ? "/home/" + std::string(std::getenv("SUDO_USER")) : (std::getenv("HOME") ? std::getenv("HOME") : ""))) + "/.config/columnlynx/"));
+#endif
 
-    bool insecureMode = options.parse(argc, argv).count("allow-selfsigned") > 0;
+    bool insecureMode = options.parse(argc, argv).count("ignore-whitelist") > 0;
     
     auto optionsObj = options.parse(argc, argv);
     if (optionsObj.count("help")) {
         std::cout << options.help() << std::endl;
         std::cout << "This software is licensed under the GPLv2-only license OR the GPLv3 license.\n";
-        std::cout << "Copyright (C) 2025, The ColumnLynx Contributors.\n";
+        std::cout << "Copyright (C) 2026, The ColumnLynx Contributors.\n";
         std::cout << "This software is provided under ABSOLUTELY NO WARRANTY, to the extent permitted by law.\n";
         return 0;
     }
@@ -72,6 +84,21 @@ int main(int argc, char** argv) {
         //WintunInitialize();
 #endif
 
+        // Get the config path, ENV > CLI > /etc/columnlynx
+        std::string configPath = optionsObj["config-dir"].as<std::string>();
+        const char* envConfigPath = std::getenv("COLUMNLYNX_CONFIG_DIR");
+        if (envConfigPath != nullptr) {
+            configPath = std::string(envConfigPath);
+        }
+
+        if (configPath.back() != '/' && configPath.back() != '\\') {
+            #if defined(__WIN32__)
+            configPath += "\\";
+            #else
+            configPath += "/";
+            #endif
+        }
+
         std::shared_ptr<VirtualInterface> tun = std::make_shared<VirtualInterface>(optionsObj["interface"].as<std::string>());
         log("Using virtual interface: " + tun->getName());
 
@@ -83,8 +110,12 @@ int main(int argc, char** argv) {
         aesKey->fill(0); // Defualt zeroed state until modified by handshake
         std::shared_ptr<uint64_t> sessionID = std::make_shared<uint64_t>(0);
 
+        if (insecureMode) {
+            warn("You have started the client with the --ignore-whitelist. This means that the client will NOT attempt to verify the server's public key. This is INSECURE and SHOULDN'T be used!");
+        }
+
         asio::io_context io;
-        auto client = std::make_shared<ColumnLynx::Net::TCP::TCPClient>(io, host, port, sodiumWrapper, aesKey, sessionID, insecureMode, tun);
+        auto client = std::make_shared<ColumnLynx::Net::TCP::TCPClient>(io, host, port, sodiumWrapper, aesKey, sessionID, insecureMode, configPath, tun);
         auto udpClient = std::make_shared<ColumnLynx::Net::UDP::UDPClient>(io, host, port, aesKey, sessionID, tun);
 
         client->start();

src/client/net/tcp/tcp_client.cpp

@@ -1,5 +1,5 @@
 // tcp_client.cpp - TCP Client for ColumnLynx
-// Copyright (C) 2025 DcruBro
+// Copyright (C) 2026 DcruBro
 // Distributed under the terms of the GNU General Public License, either version 2 only or version 3. See LICENSES/ for details.
 
 #include <columnlynx/client/net/tcp/tcp_client.hpp>
@@ -150,11 +150,12 @@ namespace ColumnLynx::Net::TCP {
     void TCPClient::mHandleMessage(ServerMessageType type, const std::string& data) {
         switch (type) {
             case ServerMessageType::HANDSHAKE_IDENTIFY: {
-                    Utils::log("Received server identity: " + data);
                     std::memcpy(mServerPublicKey, data.data(), std::min(data.size(), sizeof(mServerPublicKey)));
+                    std::string hexServerPub = Utils::bytesToHexString(mServerPublicKey, 32);
+                    Utils::log("Received server identity. Public Key: " + hexServerPub);
 
                     // Verify pubkey against whitelisted_keys
-                    std::vector<std::string> whitelistedKeys = Utils::getWhitelistedKeys();
+                    std::vector<std::string> whitelistedKeys = Utils::getWhitelistedKeys(mConfigDirPath);
                     if (std::find(whitelistedKeys.begin(), whitelistedKeys.end(), Utils::bytesToHexString(mServerPublicKey, 32)) == whitelistedKeys.end()) { // Key verification is handled in later steps of the handshake
                         if (!mInsecureMode) {
                             Utils::error("Server public key not in whitelisted_keys. Terminating connection.");

src/client/net/udp/udp_client.cpp

@@ -1,5 +1,5 @@
 // udp_client.cpp - UDP Client for ColumnLynx
-// Copyright (C) 2025 DcruBro
+// Copyright (C) 2026 DcruBro
 // Distributed under the terms of the GNU General Public License, either version 2 only or version 3. See LICENSES/ for details.
 
 #include <columnlynx/client/net/udp/udp_client.hpp>

src/common/libsodium_wrapper.cpp

@@ -1,5 +1,5 @@
 // libsodium_wrapper.cpp - Libsodium Wrapper for ColumnLynx
-// Copyright (C) 2025 DcruBro
+// Copyright (C) 2026 DcruBro
 // Distributed under the terms of the GNU General Public License, either version 2 only or version 3. See LICENSES/ for details.
 
 #include <columnlynx/common/libsodium_wrapper.hpp>
@@ -41,4 +41,27 @@ namespace ColumnLynx::Utils {
         randombytes_buf(randbytes.data(), randbytes.size());
         return randbytes;
     }
+
+    bool LibSodiumWrapper::recomputeKeys(PrivateSeed privateSeed, PublicKey storedPubKey) {
+        int res = crypto_sign_seed_keypair(mPublicKey.data(), mPrivateKey.data(), privateSeed.data());
+
+        if (res != 0) {
+            return false;
+        }
+
+        // Convert to Curve25519 keys for encryption
+        res = crypto_sign_ed25519_pk_to_curve25519(mXPublicKey.data(), mPublicKey.data());
+        res =  crypto_sign_ed25519_sk_to_curve25519(mXPrivateKey.data(), mPrivateKey.data());
+
+        if (res != 0) {
+            return false;
+        }
+
+        // Compare to stored for verification
+        if (sodium_memcmp(mPublicKey.data(), storedPubKey.data(), crypto_sign_PUBLICKEYBYTES) != 0) {
+            return false;
+        }
+
+        return true;
+    }
 }

src/common/session_registry.cpp

@@ -1,5 +1,5 @@
 // session_registry.cpp - Session Registry for ColumnLynx
-// Copyright (C) 2025 DcruBro
+// Copyright (C) 2026 DcruBro
 // Distributed under the terms of the GNU General Public License, either version 2 only or version 3. See LICENSES/ for details.
 
 #include <columnlynx/common/net/session_registry.hpp>

src/common/tcp_message_handler.cpp

@@ -1,5 +1,5 @@
 // tcp_message_handler.cpp - TCP Message Handler for ColumnLynx
-// Copyright (C) 2025 DcruBro
+// Copyright (C) 2026 DcruBro
 // Distributed under the terms of the GNU General Public License, either version 2 only or version 3. See LICENSES/ for details.
 
 #include <columnlynx/common/net/tcp/tcp_message_handler.hpp>

src/common/utils.cpp

@@ -1,29 +1,65 @@
 // utils.cpp - Utility functions for ColumnLynx
-// Copyright (C) 2025 DcruBro
+// Copyright (C) 2026 DcruBro
 // Distributed under the terms of the GNU General Public License, either version 2 only or version 3. See LICENSES/ for details.
 
 #include <columnlynx/common/utils.hpp>
 
 namespace ColumnLynx::Utils {
+    std::string unixMillisToISO8601(uint64_t unixMillis, bool local) {
+        using namespace std::chrono;
+
+        // Convert milliseconds since epoch to system_clock::time_point
+        system_clock::time_point tp = system_clock::time_point(milliseconds(unixMillis));
+
+        // Convert to time_t for localtime conversion
+        std::time_t tt = system_clock::to_time_t(tp);
+        std::tm localTm;
+
+        if (local) {
+#ifdef _WIN32
+        localtime_s(&localTm, &tt);
+#else
+        localtime_r(&tt, &localTm);
+#endif
+        } else {
+#ifdef _WIN32
+        gmtime_s(&localTm, &tt);
+#else
+        gmtime_r(&tt, &localTm);
+#endif
+        }
+
+        // Format the time to ISO 8601
+        char buffer[30];
+        std::strftime(buffer, sizeof(buffer), "%Y-%m-%dT%H:%M:%S", &localTm);
+
+        // Append milliseconds
+        auto ms = duration_cast<milliseconds>(tp.time_since_epoch()) % 1000;
+        char iso8601[34];
+        std::snprintf(iso8601, sizeof(iso8601), "%s.%03lld", buffer, static_cast<long long>(ms.count()));
+
+        return std::string(iso8601);
+    }
+
     void log(const std::string &msg) {
         uint64_t now = std::chrono::duration_cast<std::chrono::milliseconds>(std::chrono::system_clock::now().time_since_epoch()).count();
-        std::cout << "\033[0m[" << std::to_string(now) << " LOG] " << msg << std::endl;
+        std::cout << "\033[0m[" << unixMillisToISO8601(now) << " LOG] " << msg << std::endl;
     }
 
     void warn(const std::string &msg) {
         uint64_t now = std::chrono::duration_cast<std::chrono::milliseconds>(std::chrono::system_clock::now().time_since_epoch()).count();
-        std::cerr << "\033[33m[" << std::to_string(now) << " WARN] " << msg << "\033[0m" << std::endl;
+        std::cerr << "\033[33m[" << unixMillisToISO8601(now) << " WARN] " << msg << "\033[0m" << std::endl;
     }
 
     void error(const std::string &msg) {
         uint64_t now = std::chrono::duration_cast<std::chrono::milliseconds>(std::chrono::system_clock::now().time_since_epoch()).count();
-        std::cerr << "\033[31m[" << std::to_string(now) << " ERROR] " << msg << "\033[0m" << std::endl;
+        std::cerr << "\033[31m[" << unixMillisToISO8601(now) << " ERROR] " << msg << "\033[0m" << std::endl;
     }
 
     void debug(const std::string &msg) {
 #if DEBUG || _DEBUG
         uint64_t now = std::chrono::duration_cast<std::chrono::milliseconds>(std::chrono::system_clock::now().time_since_epoch()).count();
-        std::cerr << "\033[95m[" << std::to_string(now) << " DEBUG] " << msg << "\033[0m" << std::endl;
+        std::cerr << "\033[95m[" << unixMillisToISO8601(now) << " DEBUG] " << msg << "\033[0m" << std::endl;
 #else
         return;
 #endif
@@ -49,7 +85,7 @@ namespace ColumnLynx::Utils {
     }
 
     std::string getVersion() {
-        return "b0.3";
+        return "1.0.1";
     }
 
     unsigned short serverPort() {
@@ -101,14 +137,19 @@ namespace ColumnLynx::Utils {
         return bytes;
     }
 
-    std::vector<std::string> getWhitelistedKeys() {
+    std::vector<std::string> getWhitelistedKeys(std::string basePath) {
         // Currently re-reads the file every time, should be fine.
         // Advantage of it is that you don't need to reload the server binary after adding/removing keys. Disadvantage is re-reading the file every time.
         // I might redo this part.
 
         std::vector<std::string> out;
 
-        std::ifstream file("whitelisted_keys"); // TODO: This is hardcoded for now, make dynamic
+        std::ifstream file(basePath + "whitelisted_keys");
+        if (!file.is_open()) {
+            warn("Failed to open whitelisted_keys file at path: " + basePath + "whitelisted_keys");
+            return out;
+        }
+
         std::string line;
 
         while (std::getline(file, line)) {
@@ -123,6 +164,10 @@ namespace ColumnLynx::Utils {
         std::vector<std::string> readLines;
 
         std::ifstream file(path);
+        if (!file.is_open()) {
+            throw std::runtime_error("Failed to open config file at path: " + path);
+        }
+
         std::string line;
 
         while (std::getline(file, line)) {

src/common/virtual_interface.cpp

@@ -1,5 +1,5 @@
 // virtual_interface.cpp - Virtual Interface for Network Communication
-// Copyright (C) 2025 DcruBro
+// Copyright (C) 2026 DcruBro
 // Distributed under the terms of the GNU General Public License, either version 2 only or version 3. See LICENSES/ for details.
 
 #include <columnlynx/common/net/virtual_interface.hpp>
@@ -72,7 +72,7 @@ namespace ColumnLynx::Net {
 
         if (ioctl(mFd, TUNSETIFF, &ifr) < 0) {
             close(mFd);
-            throw std::runtime_error("TUNSETIFF failed: " + std::string(strerror(errno)));
+            throw std::runtime_error("TUNSETIFF failed (try running with sudo): " + std::string(strerror(errno)));
         }
 
     #elif defined(__APPLE__)
@@ -96,7 +96,7 @@ namespace ColumnLynx::Net {
 
         if (connect(mFd, (struct sockaddr*)&sc, sizeof(sc)) < 0) {
             if (errno == EPERM)
-                throw std::runtime_error("connect(AF_SYS_CONTROL) failed: Insufficient permissions (try running as root)");
+                throw std::runtime_error("connect(AF_SYS_CONTROL) failed: Insufficient permissions (try running with sudo)");
             throw std::runtime_error("connect(AF_SYS_CONTROL) failed: " + std::string(strerror(errno)));
         }
 
@@ -326,6 +326,13 @@ namespace ColumnLynx::Net {
                  mIfName.c_str()
         );
         system(cmd);
+
+        // Wipe old routes
+        //snprintf(cmd, sizeof(cmd),
+        //         "route -n delete -net %s",
+        //         mIfName.c_str()
+        //);
+        //system(cmd);
     #elif defined(_WIN32)
         char cmd[512];
         // Remove any persistent routes associated with this interface
@@ -406,6 +413,12 @@ namespace ColumnLynx::Net {
                  mIfName.c_str(), ipStr.c_str(), peerStr.c_str(), mtu, prefixStr.c_str());
         system(cmd);
 
+        // Host bits are auto-normalized by the kernel on macOS, so we don't need to worry about them not being zeroed out.
+        snprintf(cmd, sizeof(cmd),
+                 "route -n add -net %s/%d -interface %s",
+                 ipStr.c_str(), prefixLen, mIfName.c_str());
+        system(cmd);
+
         Utils::log("Executed command: " + std::string(cmd));
     
         return true;
@@ -420,41 +433,66 @@ namespace ColumnLynx::Net {
                                        uint16_t mtu)
     {
     #ifdef _WIN32
-        std::string ip  = ipv4ToString(clientIP);
-        std::string gw  = ipv4ToString(serverIP);
-        std::string mask;
+        // Interface alias → LUID → Index
+        std::wstring ifAlias(mIfName.begin(), mIfName.end());
 
-        // Convert prefixLen → subnet mask
-        uint32_t maskInt = (prefixLen == 0) ? 0 : (0xFFFFFFFF << (32 - prefixLen));
-        mask = ipv4ToString(maskInt);
+        NET_LUID luid;
+        if (ConvertInterfaceAliasToLuid(ifAlias.c_str(), &luid) != NO_ERROR)
+            return false;
 
-        // Calculate network address from IP and mask
-        uint32_t networkInt = (clientIP & maskInt);
-        std::string network = ipv4ToString(networkInt);
+        NET_IFINDEX ifIndex;
+        if (ConvertInterfaceLuidToIndex(&luid, &ifIndex) != NO_ERROR)
+            return false;
 
-        char cmd[512];
+        // ssign IPv4 address + prefix
+        MIB_UNICASTIPADDRESS_ROW addr;
+        InitializeUnicastIpAddressEntry(&addr);
 
-        // 1. Set the static IP + mask + gateway
-        snprintf(cmd, sizeof(cmd),
-            "netsh interface ip set address name=\"%s\" static %s %s %s",
-            mIfName.c_str(), ip.c_str(), mask.c_str(), gw.c_str()
-        );
-        system(cmd);
+        addr.InterfaceIndex = ifIndex;
+        addr.Address.si_family = AF_INET;
+        addr.Address.Ipv4.sin_addr.s_addr = htonl(clientIP);
+        addr.OnLinkPrefixLength = prefixLen;
+        addr.DadState = IpDadStatePreferred;
 
-        // 2. Set MTU (separate command)
-        snprintf(cmd, sizeof(cmd),
-            "netsh interface ipv4 set subinterface \"%s\" mtu=%u store=persistent",
-            mIfName.c_str(), mtu
-        );
-        system(cmd);
+        if (CreateUnicastIpAddressEntry(&addr) != NO_ERROR)
+            return false;
 
-        // 3. Add route for the VPN network to go through the TUN interface
-        // This is critical: tells Windows to send packets destined for the server/network through the TUN interface
-        snprintf(cmd, sizeof(cmd),
-            "netsh routing ip add persistentroute dest=%s/%d name=\"%s\" nexthopcfg=%s",
-            network.c_str(), prefixLen, mIfName.c_str(), gw.c_str()
-        );
-        system(cmd);
+        // Set MTU
+        MIB_IFROW ifRow;
+        ifRow.dwIndex = ifIndex;
+
+        if (GetIfEntry(&ifRow) != NO_ERROR)
+            return false;
+
+        ifRow.dwMtu = mtu;
+
+        if (SetIfEntry(&ifRow) != NO_ERROR)
+            return false;
+
+        // Add persistent route for VPN network via this interface
+        uint32_t mask =
+            (prefixLen == 0) ? 0 : (0xFFFFFFFFu << (32 - prefixLen));
+        uint32_t network = clientIP & mask;
+
+        MIB_IPFORWARD_ROW2 route;
+        InitializeIpForwardEntry(&route);
+
+        route.InterfaceIndex = ifIndex;
+        route.DestinationPrefix.Prefix.si_family = AF_INET;
+        route.DestinationPrefix.Prefix.Ipv4.sin_addr.s_addr = htonl(network);
+        route.DestinationPrefix.PrefixLength = prefixLen;
+
+        route.NextHop.si_family = AF_INET;
+        route.NextHop.Ipv4.sin_addr.s_addr = 0;
+
+        route.Metric = 1;
+        route.Protocol = static_cast<NL_ROUTE_PROTOCOL>(MIB_IPPROTO_NETMGMT);
+        route.ValidLifetime = 0xFFFFFFFF;
+        route.PreferredLifetime = 0xFFFFFFFF;
+
+        DWORD r = CreateIpForwardEntry2(&route);
+        if (r != NO_ERROR && r != ERROR_OBJECT_ALREADY_EXISTS)
+            return false;
 
         return true;
     #else

src/server/main.cpp

@@ -1,5 +1,5 @@
 // main.cpp - Server entry point for ColumnLynx
-// Copyright (C) 2025 DcruBro
+// Copyright (C) 2026 DcruBro
 // Distributed under the terms of the GNU General Public License, either version 2 only or version 3. See LICENSES/ for details.
 
 #include <asio.hpp>
@@ -16,6 +16,10 @@
 #include <cxxopts.hpp>
 #include <columnlynx/common/net/virtual_interface.hpp>
 
+#if defined(__WIN32__)
+#include <windows.h>
+#endif
+
 using asio::ip::tcp;
 using namespace ColumnLynx::Utils;
 using namespace ColumnLynx::Net::TCP;
@@ -37,7 +41,12 @@ int main(int argc, char** argv) {
 #else
         ("i,interface", "Override used interface", cxxopts::value<std::string>()->default_value("lynx0"))
 #endif
-        ("config", "Override config file path", cxxopts::value<std::string>()->default_value("./server_config"));
+#if defined(__WIN32__)
+/* Get config dir in LOCALAPPDATA\ColumnLynx\ */
+        ("config-dir", "Override config dir path", cxxopts::value<std::string>()->default_value("C:\\ProgramData\\ColumnLynx\\"));
+#else
+        ("config-dir", "Override config dir path", cxxopts::value<std::string>()->default_value("/etc/columnlynx"));
+#endif
 
     PanicHandler::init();
 
@@ -46,7 +55,7 @@ int main(int argc, char** argv) {
         if (optionsObj.count("help")) {
             std::cout << options.help() << std::endl;
             std::cout << "This software is licensed under the GPLv2-only license OR the GPLv3 license.\n";
-            std::cout << "Copyright (C) 2025, The ColumnLynx Contributors.\n";
+            std::cout << "Copyright (C) 2026, The ColumnLynx Contributors.\n";
             std::cout << "This software is provided under ABSOLUTELY NO WARRANTY, to the extent permitted by law.\n";
             return 0;
         }
@@ -60,7 +69,22 @@ int main(int argc, char** argv) {
         //WintunInitialize();
 #endif
 
-        std::unordered_map<std::string, std::string> config = Utils::getConfigMap(optionsObj["config"].as<std::string>());
+        // Get the config path, ENV > CLI > /etc/columnlynx
+        std::string configPath = optionsObj["config-dir"].as<std::string>();
+        const char* envConfigPath = std::getenv("COLUMNLYNX_CONFIG_DIR");
+        if (envConfigPath != nullptr) {
+            configPath = std::string(envConfigPath);
+        }
+
+        if (configPath.back() != '/' && configPath.back() != '\\') {
+            #if defined(__WIN32__)
+            configPath += "\\";
+            #else
+            configPath += "/";
+            #endif
+        }
+
+        std::unordered_map<std::string, std::string> config = Utils::getConfigMap(configPath + "server_config");
 
         std::shared_ptr<VirtualInterface> tun = std::make_shared<VirtualInterface>(optionsObj["interface"].as<std::string>());
         log("Using virtual interface: " + tun->getName());
@@ -75,14 +99,20 @@ int main(int argc, char** argv) {
             log("Loading keypair from config file.");
 
             PublicKey pk;
-            PrivateKey sk;
+            PrivateSeed seed;
 
-            std::copy_n(Utils::hexStringToBytes(itPrivkey->second).begin(), sk.size(), sk.begin());
+            std::copy_n(Utils::hexStringToBytes(itPrivkey->second).begin(), seed.size(), seed.begin());
             std::copy_n(Utils::hexStringToBytes(itPubkey->second).begin(), pk.size(), pk.begin());
 
-            sodiumWrapper->setKeys(pk, sk);
+            if (!sodiumWrapper->recomputeKeys(seed, pk)) {
+                throw std::runtime_error("Failed to recompute keypair from config file values!");
+            }
         } else {
+            #if defined(DEBUG)
             warn("No keypair found in config file! Using random key.");
+            #else
+            throw std::runtime_error("No keypair found in config file! Cannot start server without keys.");
+            #endif
         }
 
         log("Server public key: " + bytesToHexString(sodiumWrapper->getPublicKey(), crypto_sign_PUBLICKEYBYTES));
@@ -91,7 +121,7 @@ int main(int argc, char** argv) {
 
         asio::io_context io;
 
-        auto server = std::make_shared<TCPServer>(io, serverPort(), sodiumWrapper, hostRunning, ipv4Only);
+        auto server = std::make_shared<TCPServer>(io, serverPort(), sodiumWrapper, hostRunning, configPath, ipv4Only);
         auto udpServer = std::make_shared<UDPServer>(io, serverPort(), hostRunning, ipv4Only, tun);
 
         asio::signal_set signals(io, SIGINT, SIGTERM);
@@ -123,15 +153,28 @@ int main(int argc, char** argv) {
             }
 
             const uint8_t* ip = packet.data();
-            uint32_t dstIP = ntohl(*(uint32_t*)(ip + 16)); // IPv4 destination address offset in IPv6-mapped header
+            uint32_t srcIP = ntohl(*(uint32_t*)(ip + 12)); // IPv4 source address offset
+            uint32_t dstIP = ntohl(*(uint32_t*)(ip + 16)); // IPv4 destination address offset
         
-            auto session = SessionRegistry::getInstance().getByIP(dstIP);
-            if (!session) {
-                Utils::warn("TUN: No session found for destination IP " + VirtualInterface::ipv4ToString(dstIP));
+            // First, check if destination IP is a registered client (e.g., server responding to client or client-to-client)
+            auto dstSession = SessionRegistry::getInstance().getByIP(dstIP);
+            if (dstSession) {
+                // Destination is a registered client, forward to that client's session
+                udpServer->sendData(dstSession->sessionID, std::string(packet.begin(), packet.end()));
                 continue;
             }
 
-            udpServer->sendData(session->sessionID, std::string(packet.begin(), packet.end()));
+            // Destination is not a registered client, check if source is (for external routing)
+            auto srcSession = SessionRegistry::getInstance().getByIP(srcIP);
+            if (srcSession) {
+                // Source is a registered client, write to TUN interface to forward to external destination
+                tun->writePacket(packet);
+                continue;
+            }
+
+            // Neither source nor destination is registered, drop the packet
+            Utils::warn("TUN: No session found for source IP " + VirtualInterface::ipv4ToString(srcIP) + 
+                       " or destination IP " + VirtualInterface::ipv4ToString(dstIP));
         }
 
         log("Shutting down server...");

src/server/net/tcp/tcp_connection.cpp

@@ -1,5 +1,5 @@
 // tcp_connection.cpp - TCP Connection for ColumnLynx
-// Copyright (C) 2025 DcruBro
+// Copyright (C) 2026 DcruBro
 // Distributed under the terms of the GNU General Public License, either version 2 only or version 3. See LICENSES/ for details.
 
 #include <columnlynx/server/net/tcp/tcp_connection.hpp>
@@ -145,7 +145,7 @@ namespace ColumnLynx::Net::TCP {
                 
                 Utils::debug("Key attempted connect: " + Utils::bytesToHexString(signPk.data(), signPk.size()));
 
-                std::vector<std::string> whitelistedKeys = Utils::getWhitelistedKeys();
+                std::vector<std::string> whitelistedKeys = Utils::getWhitelistedKeys(mConfigDirPath);
 
                 if (std::find(whitelistedKeys.begin(), whitelistedKeys.end(), Utils::bytesToHexString(signPk.data(), signPk.size())) == whitelistedKeys.end()) {
                     Utils::warn("Non-whitelisted client attempted to connect, terminating. Client IP: " + reqAddr);

src/server/net/tcp/tcp_server.cpp

@@ -1,5 +1,5 @@
 // tcp_server.cpp - TCP Server for ColumnLynx
-// Copyright (C) 2025 DcruBro
+// Copyright (C) 2026 DcruBro
 // Distributed under the terms of the GNU General Public License, either version 2 only or version 3. See LICENSES/ for details.
 
 #include <columnlynx/server/net/tcp/tcp_server.hpp>
@@ -36,6 +36,7 @@ namespace ColumnLynx::Net::TCP {
                     std::move(socket),
                     mSodiumWrapper,
                     &mRawServerConfig,
+                    mConfigDirPath,
                     [this](std::shared_ptr<TCPConnection> c) {
                         mClients.erase(c);
                         Utils::log("Client removed.");

src/server/net/udp/udp_server.cpp

@@ -1,5 +1,5 @@
 // udp_server.cpp - UDP Server for ColumnLynx
-// Copyright (C) 2025 DcruBro
+// Copyright (C) 2026 DcruBro
 // Distributed under the terms of the GNU General Public License, either version 2 only or version 3. See LICENSES/ for details.
 
 #include <columnlynx/server/net/udp/udp_server.hpp>