Merge pull request #29 from firecat53/flake

Flake update for newt 1.1.3

.github/workflows/cicd.yml

@@ -14,6 +14,9 @@ jobs:
             - name: Checkout code
               uses: actions/checkout@v3
 
+            - name: Set up QEMU
+              uses: docker/setup-qemu-action@v3
+
             - name: Set up Docker Buildx
               uses: docker/setup-buildx-action@v2
 

.gitignore

@@ -1,3 +1,6 @@
 newt
 .DS_Store
-bin/
+bin/
+.idea
+*.iml
+certs/

README.md

@@ -36,8 +36,10 @@ When Newt receives WireGuard control messages, it will use the information encod
 - `secret`: A unique secret (not shared and kept private) used to authenticate the client ID with the websocket in order to receive commands. 
 - `dns`: DNS server to use to resolve the endpoint
 - `log-level` (optional): The log level to use. Default: INFO
+- `updown` (optional): A script to be called when targets are added or removed.
+- `tls-client-cert` (optional): Client certificate (p12 or pfx) for mTLS. See [mTLS](#mtls)
 
-Example:
+- Example:
 
 ```bash
 ./newt \
@@ -92,6 +94,52 @@ WantedBy=multi-user.target
 
 Make sure to `mv ./newt /usr/local/bin/newt`!
 
+### Updown
+
+You can pass in a updown script for Newt to call when it is adding or removing a target:
+
+`--updown "python3 test.py"`
+
+It will get called with args when a target is added: 
+`python3 test.py add tcp localhost:8556`
+`python3 test.py remove tcp localhost:8556`
+
+Returning a string from the script in the format of a target (`ip:dst` so `10.0.0.1:8080`) it will override the target and use this value instead to proxy.
+
+You can look at updown.py as a reference script to get started!
+
+### mTLS
+Newt supports mutual TLS (mTLS) authentication, if the server has been configured to request a client certificate.
+* Only PKCS12 (.p12 or .pfx) file format is accepted
+* The PKCS12 file must contain: 
+  * Private key
+  * Public certificate
+  * CA certificate
+* Encrypted PKCS12 files are currently not supported
+
+Examples:
+
+```bash
+./newt \
+--id 31frd0uzbjvp721 \
+--secret h51mmlknrvrwv8s4r1i210azhumt6isgbpyavxodibx1k2d6 \
+--endpoint https://example.com \
+--tls-client-cert ./client.p12
+```
+
+```yaml
+services:
+  newt:
+    image: fosrl/newt
+    container_name: newt
+    restart: unless-stopped
+    environment:
+      - PANGOLIN_ENDPOINT=https://example.com
+      - NEWT_ID=2ix2t8xk22ubpfy 
+      - NEWT_SECRET=nnisrfsdfc7prqsp9ewo1dvtvci50j5uiqotez00dgap0ii2 
+      - TLS_CLIENT_CERT=./client.p12 
+```
+
 ## Build
 
 ### Container 
@@ -110,6 +158,16 @@ Make sure to have Go 1.23.1 installed.
 make local
 ```
 
+### Nix Flake
+
+```bash
+nix build
+```
+
+Binary will be at `./result/bin/newt`
+
+Development shell available with `nix develop`
+
 ## Licensing
 
 Newt is dual licensed under the AGPLv3 and the Fossorial Commercial license. For inquiries about commercial licensing, please contact us.

flake.lock

@@ -0,0 +1,27 @@
+{
+  "nodes": {
+    "nixpkgs": {
+      "locked": {
+        "lastModified": 1743827369,
+        "narHash": "sha256-rpqepOZ8Eo1zg+KJeWoq1HAOgoMCDloqv5r2EAa9TSA=",
+        "owner": "NixOS",
+        "repo": "nixpkgs",
+        "rev": "42a1c966be226125b48c384171c44c651c236c22",
+        "type": "github"
+      },
+      "original": {
+        "owner": "NixOS",
+        "ref": "nixos-unstable",
+        "repo": "nixpkgs",
+        "type": "github"
+      }
+    },
+    "root": {
+      "inputs": {
+        "nixpkgs": "nixpkgs"
+      }
+    }
+  },
+  "root": "root",
+  "version": 7
+}

flake.nix

@@ -0,0 +1,65 @@
+{
+  description = "newt - A tunneling client for Pangolin";
+
+  inputs = {
+    nixpkgs.url = "github:NixOS/nixpkgs/nixos-unstable";
+  };
+
+  outputs =
+    { self, nixpkgs }:
+    let
+      supportedSystems = [
+        "x86_64-linux"
+        "aarch64-linux"
+        "x86_64-darwin"
+        "aarch64-darwin"
+      ];
+      forAllSystems = nixpkgs.lib.genAttrs supportedSystems;
+      pkgsFor = system: nixpkgs.legacyPackages.${system};
+    in
+    {
+      packages = forAllSystems (
+        system:
+        let
+          pkgs = pkgsFor system;
+        in
+        {
+          default = self.packages.${system}.pangolin-newt;
+          pangolin-newt = pkgs.buildGoModule {
+            pname = "pangolin-newt";
+            version = "1.1.3";
+
+            src = ./.;
+
+            vendorHash = "sha256-sTtiBBkZ9cuhWnrn2VG20kv4nzNFfdzP5p+ewESCjyM=";
+
+            meta = with pkgs.lib; {
+              description = "A tunneling client for Pangolin";
+              homepage = "https://github.com/fosrl/newt";
+              license = licenses.gpl3;
+              maintainers = [ ];
+            };
+          };
+        }
+      );
+      devShells = forAllSystems (
+        system:
+        let
+          pkgs = pkgsFor system;
+        in
+        {
+          default = pkgs.mkShell {
+            buildInputs = with pkgs; [
+              go
+              gopls
+              gotools
+              go-outline
+              gopkgs
+              godef
+              golint
+            ];
+          };
+        }
+      );
+    };
+}

go.mod

@@ -4,17 +4,20 @@ go 1.23.1
 
 toolchain go1.23.2
 
-require golang.zx2c4.com/wireguard v0.0.0-20231211153847-12269c276173
+require (
+	github.com/gorilla/websocket v1.5.3
+	golang.org/x/net v0.30.0
+	golang.zx2c4.com/wireguard v0.0.0-20231211153847-12269c276173
+	golang.zx2c4.com/wireguard/wgctrl v0.0.0-20230429144221-925a1e7659e6
+	gvisor.dev/gvisor v0.0.0-20230927004350-cbd86285d259
+	software.sslmate.com/src/go-pkcs12 v0.5.0
+)
 
 require (
 	github.com/google/btree v1.1.2 // indirect
-	github.com/gorilla/websocket v1.5.3 // indirect
+	github.com/google/go-cmp v0.6.0 // indirect
 	golang.org/x/crypto v0.28.0 // indirect
-	golang.org/x/exp v0.0.0-20250106191152-7588d65b2ba8 // indirect
-	golang.org/x/net v0.30.0 // indirect
 	golang.org/x/sys v0.26.0 // indirect
 	golang.org/x/time v0.7.0 // indirect
 	golang.zx2c4.com/wintun v0.0.0-20230126152724-0fa3db229ce2 // indirect
-	golang.zx2c4.com/wireguard/wgctrl v0.0.0-20230429144221-925a1e7659e6 // indirect
-	gvisor.dev/gvisor v0.0.0-20230927004350-cbd86285d259 // indirect
 )

go.sum

@@ -1,11 +1,11 @@
 github.com/google/btree v1.1.2 h1:xf4v41cLI2Z6FxbKm+8Bu+m8ifhj15JuZ9sa0jZCMUU=
 github.com/google/btree v1.1.2/go.mod h1:qOPhT0dTNdNzV6Z/lhRX0YXUafgPLFUh+gZMl761Gm4=
+github.com/google/go-cmp v0.6.0 h1:ofyhxvXcZhMsU5ulbFiLKl/XBFqE1GSq7atu8tAmTRI=
+github.com/google/go-cmp v0.6.0/go.mod h1:17dUlkBOakJ0+DkrSSNjCkIjxS6bF9zb3elmeNGIjoY=
 github.com/gorilla/websocket v1.5.3 h1:saDtZ6Pbx/0u+bgYQ3q96pZgCzfhKXGPqt7kZ72aNNg=
 github.com/gorilla/websocket v1.5.3/go.mod h1:YR8l580nyteQvAITg2hZ9XVh4b55+EU/adAjf1fMHhE=
 golang.org/x/crypto v0.28.0 h1:GBDwsMXVQi34v5CCYUm2jkJvu4cbtru2U4TN2PSyQnw=
 golang.org/x/crypto v0.28.0/go.mod h1:rmgy+3RHxRZMyY0jjAJShp2zgEdOqj2AO7U0pYmeQ7U=
-golang.org/x/exp v0.0.0-20250106191152-7588d65b2ba8 h1:yqrTHse8TCMW1M1ZCP+VAR/l0kKxwaAIqN/il7x4voA=
-golang.org/x/exp v0.0.0-20250106191152-7588d65b2ba8/go.mod h1:tujkw807nyEEAamNbDrEGzRav+ilXA7PCRAd6xsmwiU=
 golang.org/x/net v0.30.0 h1:AcW1SDZMkb8IpzCdQUaIq2sP4sZ4zw+55h6ynffypl4=
 golang.org/x/net v0.30.0/go.mod h1:2wGyMJ5iFasEhkwi13ChkO/t1ECNC4X4eBKkVFyYFlU=
 golang.org/x/sys v0.26.0 h1:KHjCJyddX0LoSTb3J+vWpupP9p0oznkqVk/IfjymZbo=
@@ -20,3 +20,5 @@ golang.zx2c4.com/wireguard/wgctrl v0.0.0-20230429144221-925a1e7659e6 h1:CawjfCvY
 golang.zx2c4.com/wireguard/wgctrl v0.0.0-20230429144221-925a1e7659e6/go.mod h1:3rxYc4HtVcSG9gVaTs2GEBdehh+sYPOwKtyUWEOTb80=
 gvisor.dev/gvisor v0.0.0-20230927004350-cbd86285d259 h1:TbRPT0HtzFP3Cno1zZo7yPzEEnfu8EjLfl6IU9VfqkQ=
 gvisor.dev/gvisor v0.0.0-20230927004350-cbd86285d259/go.mod h1:AVgIgHMwK63XvmAzWG9vLQ41YnVHN0du0tEC46fI7yY=
+software.sslmate.com/src/go-pkcs12 v0.5.0 h1:EC6R394xgENTpZ4RltKydeDUjtlM5drOYIG9c6TVj2M=
+software.sslmate.com/src/go-pkcs12 v0.5.0/go.mod h1:Qiz0EyvDRJjjxGyUQa2cCNZn/wMyzrRJ/qcDXOQazLI=

logger/logger.go

@@ -53,7 +53,23 @@ func (l *Logger) log(level LogLevel, format string, args ...interface{}) {
 	if level < l.level {
 		return
 	}
-	timestamp := time.Now().Format("2006/01/02 15:04:05")
+
+	// Get timezone from environment variable or use local timezone
+	timezone := os.Getenv("LOGGER_TIMEZONE")
+	var location *time.Location
+	var err error
+
+	if timezone != "" {
+		location, err = time.LoadLocation(timezone)
+		if err != nil {
+			// If invalid timezone, fall back to local
+			location = time.Local
+		}
+	} else {
+		location = time.Local
+	}
+
+	timestamp := time.Now().In(location).Format("2006/01/02 15:04:05")
 	message := fmt.Sprintf(format, args...)
 	l.logger.Printf("%s: %s %s", level.String(), timestamp, message)
 }

main.go

@@ -11,6 +11,7 @@ import (
 	"net"
 	"net/netip"
 	"os"
+	"os/exec"
 	"os/signal"
 	"strconv"
 	"strings"
@@ -114,7 +115,12 @@ func ping(tnet *netstack.Net, dst string) error {
 }
 
 func startPingCheck(tnet *netstack.Net, serverIP string, stopChan chan struct{}) {
-	ticker := time.NewTicker(10 * time.Second)
+	initialInterval := 10 * time.Second
+	maxInterval := 60 * time.Second
+	currentInterval := initialInterval
+	consecutiveFailures := 0
+
+	ticker := time.NewTicker(currentInterval)
 	defer ticker.Stop()
 
 	go func() {
@@ -123,8 +129,34 @@ func startPingCheck(tnet *netstack.Net, serverIP string, stopChan chan struct{})
 			case <-ticker.C:
 				err := ping(tnet, serverIP)
 				if err != nil {
-					logger.Warn("Periodic ping failed: %v", err)
+					consecutiveFailures++
+					logger.Warn("Periodic ping failed (%d consecutive failures): %v",
+						consecutiveFailures, err)
 					logger.Warn("HINT: Do you have UDP port 51820 (or the port in config.yml) open on your Pangolin server?")
+
+					// Increase interval if we have consistent failures, with a maximum cap
+					if consecutiveFailures >= 3 && currentInterval < maxInterval {
+						// Increase by 50% each time, up to the maximum
+						currentInterval = time.Duration(float64(currentInterval) * 1.5)
+						if currentInterval > maxInterval {
+							currentInterval = maxInterval
+						}
+						ticker.Reset(currentInterval)
+						logger.Info("Increased ping check interval to %v due to consecutive failures",
+							currentInterval)
+					}
+				} else {
+					// On success, if we've backed off, gradually return to normal interval
+					if currentInterval > initialInterval {
+						currentInterval = time.Duration(float64(currentInterval) * 0.8)
+						if currentInterval < initialInterval {
+							currentInterval = initialInterval
+						}
+						ticker.Reset(currentInterval)
+						logger.Info("Decreased ping check interval to %v after successful ping",
+							currentInterval)
+					}
+					consecutiveFailures = 0
 				}
 			case <-stopChan:
 				logger.Info("Stopping ping check")
@@ -134,34 +166,97 @@ func startPingCheck(tnet *netstack.Net, serverIP string, stopChan chan struct{})
 	}()
 }
 
+// Function to track connection status and trigger reconnection as needed
+func monitorConnectionStatus(tnet *netstack.Net, serverIP string, client *websocket.Client) {
+	const checkInterval = 30 * time.Second
+	connectionLost := false
+	ticker := time.NewTicker(checkInterval)
+	defer ticker.Stop()
+
+	for {
+		select {
+		case <-ticker.C:
+			// Try a ping to see if connection is alive
+			err := ping(tnet, serverIP)
+
+			if err != nil && !connectionLost {
+				// We just lost connection
+				connectionLost = true
+				logger.Warn("Connection to server lost. Continuous reconnection attempts will be made.")
+
+				// Notify the user they might need to check their network
+				logger.Warn("Please check your internet connection and ensure the Pangolin server is online.")
+				logger.Warn("Newt will continue reconnection attempts automatically when connectivity is restored.")
+			} else if err == nil && connectionLost {
+				// Connection has been restored
+				connectionLost = false
+				logger.Info("Connection to server restored!")
+
+				// Tell the server we're back
+				err := client.SendMessage("newt/wg/register", map[string]interface{}{
+					"publicKey": fmt.Sprintf("%s", privateKey.PublicKey()),
+				})
+
+				if err != nil {
+					logger.Error("Failed to send registration message after reconnection: %v", err)
+				} else {
+					logger.Info("Successfully re-registered with server after reconnection")
+				}
+			}
+		}
+	}
+}
+
 func pingWithRetry(tnet *netstack.Net, dst string) error {
 	const (
-		maxAttempts = 5
-		retryDelay  = 2 * time.Second
+		initialMaxAttempts = 15
+		initialRetryDelay  = 2 * time.Second
+		maxRetryDelay      = 60 * time.Second // Cap the maximum delay
 	)
 
-	var lastErr error
-	for attempt := 1; attempt <= maxAttempts; attempt++ {
-		logger.Info("Ping attempt %d of %d", attempt, maxAttempts)
-
-		if err := ping(tnet, dst); err != nil {
-			lastErr = err
-			logger.Warn("Ping attempt %d failed: %v", attempt, err)
-
-			if attempt < maxAttempts {
-				time.Sleep(retryDelay)
-				continue
-			}
-			return fmt.Errorf("all ping attempts failed after %d tries, last error: %w",
-				maxAttempts, lastErr)
-		}
+	attempt := 1
+	retryDelay := initialRetryDelay
 
+	// First try with the initial parameters
+	logger.Info("Ping attempt %d", attempt)
+	if err := ping(tnet, dst); err == nil {
 		// Successful ping
 		return nil
+	} else {
+		logger.Warn("Ping attempt %d failed: %v", attempt, err)
 	}
 
-	// This shouldn't be reached due to the return in the loop, but added for completeness
-	return fmt.Errorf("unexpected error: all ping attempts failed")
+	// Start a goroutine that will attempt pings indefinitely with increasing delays
+	go func() {
+		attempt = 2 // Continue from attempt 2
+
+		for {
+			logger.Info("Ping attempt %d", attempt)
+
+			if err := ping(tnet, dst); err != nil {
+				logger.Warn("Ping attempt %d failed: %v", attempt, err)
+
+				// Increase delay after certain thresholds but cap it
+				if attempt%5 == 0 && retryDelay < maxRetryDelay {
+					retryDelay = time.Duration(float64(retryDelay) * 1.5)
+					if retryDelay > maxRetryDelay {
+						retryDelay = maxRetryDelay
+					}
+					logger.Info("Increasing ping retry delay to %v", retryDelay)
+				}
+
+				time.Sleep(retryDelay)
+				attempt++
+			} else {
+				// Successful ping
+				logger.Info("Ping succeeded after %d attempts", attempt)
+				return
+			}
+		}
+	}()
+
+	// Return an error for the first batch of attempts (to maintain compatibility with existing code)
+	return fmt.Errorf("initial ping attempts failed, continuing in background")
 }
 
 func parseLogLevel(level string) logger.LogLevel {
@@ -244,19 +339,21 @@ func resolveDomain(domain string) (string, error) {
 	return ipAddr, nil
 }
 
-func main() {
-	var (
-		endpoint   string
-		id         string
-		secret     string
-		mtu        string
-		mtuInt     int
-		dns        string
-		privateKey wgtypes.Key
-		err        error
-		logLevel   string
-	)
+var (
+	endpoint      string
+	id            string
+	secret        string
+	mtu           string
+	mtuInt        int
+	dns           string
+	privateKey    wgtypes.Key
+	err           error
+	logLevel      string
+	updownScript  string
+	tlsPrivateKey string
+)
 
+func main() {
 	// if PANGOLIN_ENDPOINT, NEWT_ID, and NEWT_SECRET are set as environment variables, they will be used as default values
 	endpoint = os.Getenv("PANGOLIN_ENDPOINT")
 	id = os.Getenv("NEWT_ID")
@@ -264,6 +361,8 @@ func main() {
 	mtu = os.Getenv("MTU")
 	dns = os.Getenv("DNS")
 	logLevel = os.Getenv("LOG_LEVEL")
+	updownScript = os.Getenv("UPDOWN_SCRIPT")
+	tlsPrivateKey = os.Getenv("TLS_CLIENT_CERT")
 
 	if endpoint == "" {
 		flag.StringVar(&endpoint, "endpoint", "", "Endpoint of your pangolin server")
@@ -283,6 +382,12 @@ func main() {
 	if logLevel == "" {
 		flag.StringVar(&logLevel, "log-level", "INFO", "Log level (DEBUG, INFO, WARN, ERROR, FATAL)")
 	}
+	if updownScript == "" {
+		flag.StringVar(&updownScript, "updown", "", "Path to updown script to be called when targets are added or removed")
+	}
+	if tlsPrivateKey == "" {
+		flag.StringVar(&tlsPrivateKey, "tls-client-cert", "", "Path to client certificate used for mTLS")
+	}
 
 	// do a --version check
 	version := flag.Bool("version", false, "Print the version")
@@ -308,12 +413,16 @@ func main() {
 	if err != nil {
 		logger.Fatal("Failed to generate private key: %v", err)
 	}
-
+	var opt websocket.ClientOption
+	if tlsPrivateKey != "" {
+		opt = websocket.WithTLSConfig(tlsPrivateKey)
+	}
 	// Create a new client
 	client, err := websocket.NewClient(
 		id,     // CLI arg takes precedence
 		secret, // CLI arg takes precedence
 		endpoint,
+		opt,
 	)
 	if err != nil {
 		logger.Fatal("Failed to create client: %v", err)
@@ -347,13 +456,8 @@ func main() {
 
 		if connected {
 			logger.Info("Already connected! But I will send a ping anyway...")
-			// ping(tnet, wgData.ServerIP)
-			err = pingWithRetry(tnet, wgData.ServerIP)
-			if err != nil {
-				// Handle complete failure after all retries
-				logger.Warn("Failed to ping %s: %v", wgData.ServerIP, err)
-				logger.Warn("HINT: Do you have UDP port 51280 (or the port in config.yml) open on your Pangolin server?")
-			}
+			// Even if pingWithRetry returns an error, it will continue trying in the background
+			_ = pingWithRetry(tnet, wgData.ServerIP) // Ignoring initial error as pings will continue
 			return
 		}
 
@@ -408,17 +512,18 @@ persistent_keepalive_interval=5`, fixKey(fmt.Sprintf("%s", privateKey)), fixKey(
 		}
 
 		logger.Info("WireGuard device created. Lets ping the server now...")
-		// Ping to bring the tunnel up on the server side quickly
-		// ping(tnet, wgData.ServerIP)
-		err = pingWithRetry(tnet, wgData.ServerIP)
-		if err != nil {
-			// Handle complete failure after all retries
-			logger.Error("Failed to ping %s: %v", wgData.ServerIP, err)
-		}
 
+		// Even if pingWithRetry returns an error, it will continue trying in the background
+		_ = pingWithRetry(tnet, wgData.ServerIP)
+
+		// Always mark as connected and start the proxy manager regardless of initial ping result
+		// as the pings will continue in the background
 		if !connected {
 			logger.Info("Starting ping check")
 			startPingCheck(tnet, wgData.ServerIP, pingStopChan)
+
+			// Start connection monitoring in a separate goroutine
+			go monitorConnectionStatus(tnet, wgData.ServerIP, client)
 		}
 
 		// Create proxy manager
@@ -546,10 +651,13 @@ persistent_keepalive_interval=5`, fixKey(fmt.Sprintf("%s", privateKey)), fixKey(
 	// Wait for interrupt signal
 	sigCh := make(chan os.Signal, 1)
 	signal.Notify(sigCh, syscall.SIGINT, syscall.SIGTERM)
-	<-sigCh
+	sigReceived := <-sigCh
 
 	// Cleanup
-	dev.Close()
+	logger.Info("Received %s signal, stopping", sigReceived.String())
+	if dev != nil {
+		dev.Close()
+	}
 }
 
 func parseTargetData(data interface{}) (TargetData, error) {
@@ -586,6 +694,18 @@ func updateTargets(pm *proxy.ProxyManager, action string, tunnelIP string, proto
 
 		if action == "add" {
 			target := parts[1] + ":" + parts[2]
+
+			// Call updown script if provided
+			processedTarget := target
+			if updownScript != "" {
+				newTarget, err := executeUpdownScript(action, proto, target)
+				if err != nil {
+					logger.Warn("Updown script error: %v", err)
+				} else if newTarget != "" {
+					processedTarget = newTarget
+				}
+			}
+
 			// Only remove the specific target if it exists
 			err := pm.RemoveTarget(proto, tunnelIP, port)
 			if err != nil {
@@ -596,10 +716,21 @@ func updateTargets(pm *proxy.ProxyManager, action string, tunnelIP string, proto
 			}
 
 			// Add the new target
-			pm.AddTarget(proto, tunnelIP, port, target)
+			pm.AddTarget(proto, tunnelIP, port, processedTarget)
 
 		} else if action == "remove" {
 			logger.Info("Removing target with port %d", port)
+
+			target := parts[1] + ":" + parts[2]
+
+			// Call updown script if provided
+			if updownScript != "" {
+				_, err := executeUpdownScript(action, proto, target)
+				if err != nil {
+					logger.Warn("Updown script error: %v", err)
+				}
+			}
+
 			err := pm.RemoveTarget(proto, tunnelIP, port)
 			if err != nil {
 				logger.Error("Failed to remove target: %v", err)
@@ -610,3 +741,45 @@ func updateTargets(pm *proxy.ProxyManager, action string, tunnelIP string, proto
 
 	return nil
 }
+
+func executeUpdownScript(action, proto, target string) (string, error) {
+	if updownScript == "" {
+		return target, nil
+	}
+
+	// Split the updownScript in case it contains spaces (like "/usr/bin/python3 script.py")
+	parts := strings.Fields(updownScript)
+	if len(parts) == 0 {
+		return target, fmt.Errorf("invalid updown script command")
+	}
+
+	var cmd *exec.Cmd
+	if len(parts) == 1 {
+		// If it's a single executable
+		logger.Info("Executing updown script: %s %s %s %s", updownScript, action, proto, target)
+		cmd = exec.Command(parts[0], action, proto, target)
+	} else {
+		// If it includes interpreter and script
+		args := append(parts[1:], action, proto, target)
+		logger.Info("Executing updown script: %s %s %s %s %s", parts[0], strings.Join(parts[1:], " "), action, proto, target)
+		cmd = exec.Command(parts[0], args...)
+	}
+
+	output, err := cmd.Output()
+	if err != nil {
+		if exitErr, ok := err.(*exec.ExitError); ok {
+			return "", fmt.Errorf("updown script execution failed (exit code %d): %s",
+				exitErr.ExitCode(), string(exitErr.Stderr))
+		}
+		return "", fmt.Errorf("updown script execution failed: %v", err)
+	}
+
+	// If the script returns a new target, use it
+	newTarget := strings.TrimSpace(string(output))
+	if newTarget != "" {
+		logger.Info("Updown script returned new target: %s", newTarget)
+		return newTarget, nil
+	}
+
+	return target, nil
+}

self-signed-certs-for-mtls.sh

@@ -0,0 +1,125 @@
+#!/usr/bin/env bash
+set -eu
+
+echo -n "Enter username for certs (eg alice): "
+read CERT_USERNAME
+echo
+
+echo -n "Enter domain of user (eg example.com): "
+read DOMAIN
+echo
+
+# Prompt for password at the start
+echo -n "Enter password for certificate: "
+read -s PASSWORD
+echo
+echo -n "Confirm password: "
+read -s PASSWORD2
+echo
+
+if [ "$PASSWORD" != "$PASSWORD2" ]; then
+    echo "Passwords don't match!"
+    exit 1
+fi
+CA_DIR="./certs/ca"
+CLIENT_DIR="./certs/clients"
+FILE_PREFIX=$(echo "$CERT_USERNAME-at-$DOMAIN" | sed 's/\./-/')
+
+mkdir -p "$CA_DIR"
+mkdir -p "$CLIENT_DIR"
+
+if [ ! -f "$CA_DIR/ca.crt" ]; then
+# Generate CA private key
+  openssl genrsa -out "$CA_DIR/ca.key" 4096
+  echo "CA key ✅"
+
+  # Generate CA root certificate
+  openssl req -x509 -new -nodes \
+    -key "$CA_DIR/ca.key" \
+    -sha256 \
+    -days 3650 \
+    -out "$CA_DIR/ca.crt" \
+    -subj "/C=US/ST=State/L=City/O=Organization/OU=Unit/CN=ca.$DOMAIN"
+
+  echo "CA cert ✅"
+fi
+
+# Generate client private key
+openssl genrsa -aes256 -passout pass:"$PASSWORD" -out "$CLIENT_DIR/$FILE_PREFIX.key" 2048
+echo "Client key ✅"
+
+# Generate client Certificate Signing Request (CSR)
+openssl req -new \
+  -key "$CLIENT_DIR/$FILE_PREFIX.key" \
+  -out "$CLIENT_DIR/$FILE_PREFIX.csr" \
+  -passin pass:"$PASSWORD" \
+  -subj "/C=US/ST=State/L=City/O=Organization/OU=Unit/CN=$CERT_USERNAME@$DOMAIN"
+echo "Client cert ✅"
+
+echo -n "Signing client cert..."
+# Create client certificate configuration file
+cat > "$CLIENT_DIR/$FILE_PREFIX.ext" << EOF
+authorityKeyIdentifier=keyid,issuer
+basicConstraints=CA:FALSE
+keyUsage = digitalSignature, nonRepudiation, keyEncipherment, dataEncipherment
+subjectAltName = @alt_names
+
+[alt_names]
+DNS.1 = $DOMAIN
+EOF
+
+# Generate client certificate signed by CA
+openssl x509 -req \
+  -in "$CLIENT_DIR/$FILE_PREFIX.csr" \
+  -CA "$CA_DIR/ca.crt" \
+  -CAkey "$CA_DIR/ca.key" \
+  -CAcreateserial \
+  -out "$CLIENT_DIR/$FILE_PREFIX.crt" \
+  -days 365 \
+  -sha256 \
+  -extfile "$CLIENT_DIR/$FILE_PREFIX.ext"
+
+# Verify the client certificate
+openssl verify -CAfile "$CA_DIR/ca.crt" "$CLIENT_DIR/$FILE_PREFIX.crt"
+echo "Signed ✅"
+
+# Create encrypted PEM bundle
+openssl rsa -in "$CLIENT_DIR/$FILE_PREFIX.key" -passin pass:"$PASSWORD" \
+    | cat "$CLIENT_DIR/$FILE_PREFIX.crt" - > "$CLIENT_DIR/$FILE_PREFIX-bundle.enc.pem"
+
+
+# Convert to PKCS12
+echo "Converting to PKCS12 format..."
+openssl pkcs12 -export \
+  -out "$CLIENT_DIR/$FILE_PREFIX.enc.p12" \
+  -inkey "$CLIENT_DIR/$FILE_PREFIX.key" \
+  -in "$CLIENT_DIR/$FILE_PREFIX.crt" \
+  -certfile "$CA_DIR/ca.crt" \
+  -name "$CERT_USERNAME@$DOMAIN" \
+  -passin pass:"$PASSWORD" \
+  -passout pass:"$PASSWORD"
+echo "Converted to encrypted p12 for macOS ✅"
+
+# Convert to PKCS12 format without encryption
+echo "Converting to non-encrypted PKCS12 format..."
+openssl pkcs12 -export \
+  -out "$CLIENT_DIR/$FILE_PREFIX.p12" \
+  -inkey "$CLIENT_DIR/$FILE_PREFIX.key" \
+  -in "$CLIENT_DIR/$FILE_PREFIX.crt" \
+  -certfile "$CA_DIR/ca.crt" \
+  -name "$CERT_USERNAME@$DOMAIN" \
+  -passin pass:"$PASSWORD" \
+  -passout pass:""
+echo "Converted to non-encrypted p12  ✅"
+
+# Clean up intermediate files
+rm "$CLIENT_DIR/$FILE_PREFIX.csr" "$CLIENT_DIR/$FILE_PREFIX.ext" "$CA_DIR/ca.srl"
+echo
+echo
+
+echo "CA certificate:     $CA_DIR/ca.crt"
+echo "CA private key:     $CA_DIR/ca.key"
+echo "Client certificate: $CLIENT_DIR/$FILE_PREFIX.crt"
+echo "Client private key: $CLIENT_DIR/$FILE_PREFIX.key"
+echo "Client cert bundle: $CLIENT_DIR/$FILE_PREFIX.p12"
+echo "Client cert bundle (encrypted): $CLIENT_DIR/$FILE_PREFIX.enc.p12"

updown.py

@@ -0,0 +1,77 @@
+"""
+Sample updown script for Newt proxy
+Usage: update.py <action> <protocol> <target>
+
+Parameters:
+- action: 'add' or 'remove'
+- protocol: 'tcp' or 'udp'
+- target: the target address in format 'host:port'
+
+If the action is 'add', the script can return a modified target that
+will be used instead of the original.
+"""
+
+import sys
+import logging
+import json
+from datetime import datetime
+
+# Configure logging
+LOG_FILE = "/tmp/newt-updown.log"
+logging.basicConfig(
+    filename=LOG_FILE,
+    level=logging.INFO,
+    format='%(asctime)s - %(levelname)s - %(message)s'
+)
+
+def log_event(action, protocol, target):
+    """Log each event to a file for auditing purposes"""
+    timestamp = datetime.now().isoformat()
+    event = {
+        "timestamp": timestamp,
+        "action": action,
+        "protocol": protocol,
+        "target": target
+    }
+    logging.info(json.dumps(event))
+
+def handle_add(protocol, target):
+    """Handle 'add' action"""
+    logging.info(f"Adding {protocol} target: {target}")
+    
+def handle_remove(protocol, target):
+    """Handle 'remove' action"""
+    logging.info(f"Removing {protocol} target: {target}")
+    # For remove action, no return value is expected or used
+    
+def main():
+    # Check arguments
+    if len(sys.argv) != 4:
+        logging.error(f"Invalid arguments: {sys.argv}")
+        sys.exit(1)
+    
+    action = sys.argv[1]
+    protocol = sys.argv[2]
+    target = sys.argv[3]
+    
+    # Log the event
+    log_event(action, protocol, target)
+    
+    # Handle the action
+    if action == "add":
+        new_target = handle_add(protocol, target)
+        # Print the new target to stdout (if empty, no change will be made)
+        if new_target and new_target != target:
+            print(new_target)
+    elif action == "remove":
+        handle_remove(protocol, target)
+    else:
+        logging.error(f"Unknown action: {action}")
+        sys.exit(1)
+
+if __name__ == "__main__":
+    try:
+        main()
+    except Exception as e:
+        logging.error(f"Unhandled exception: {e}")
+        sys.exit(1)

websocket/client.go

@@ -2,27 +2,29 @@ package websocket
 
 import (
 	"bytes"
+	"crypto/tls"
+	"crypto/x509"
 	"encoding/json"
 	"fmt"
 	"net/http"
 	"net/url"
+	"os"
+	"software.sslmate.com/src/go-pkcs12"
 	"strings"
 	"sync"
 	"time"
 
 	"github.com/fosrl/newt/logger"
-
 	"github.com/gorilla/websocket"
 )
 
 type Client struct {
-	conn        *websocket.Conn
-	config      *Config
-	baseURL     string
-	handlers    map[string]MessageHandler
-	done        chan struct{}
-	handlersMux sync.RWMutex
-
+	conn              *websocket.Conn
+	config            *Config
+	baseURL           string
+	handlers          map[string]MessageHandler
+	done              chan struct{}
+	handlersMux       sync.RWMutex
 	reconnectInterval time.Duration
 	isConnected       bool
 	reconnectMux      sync.RWMutex
@@ -41,6 +43,12 @@ func WithBaseURL(url string) ClientOption {
 	}
 }
 
+func WithTLSConfig(tlsClientCertPath string) ClientOption {
+	return func(c *Client) {
+		c.config.TlsClientCert = tlsClientCertPath
+	}
+}
+
 func (c *Client) OnConnect(callback func() error) {
 	c.onConnect = callback
 }
@@ -63,8 +71,13 @@ func NewClient(newtID, secret string, endpoint string, opts ...ClientOption) (*C
 	}
 
 	// Apply options before loading config
-	for _, opt := range opts {
-		opt(client)
+	if opts != nil {
+		for _, opt := range opts {
+			if opt == nil {
+				continue
+			}
+			opt(client)
+		}
 	}
 
 	// Load existing config if available
@@ -149,6 +162,14 @@ func (c *Client) getToken() (string, error) {
 	// Ensure we have the base URL without trailing slashes
 	baseEndpoint := strings.TrimRight(baseURL.String(), "/")
 
+	var tlsConfig *tls.Config = nil
+	if c.config.TlsClientCert != "" {
+		tlsConfig, err = loadClientCertificate(c.config.TlsClientCert)
+		if err != nil {
+			return "", fmt.Errorf("failed to load certificate %s: %w", c.config.TlsClientCert, err)
+		}
+	}
+
 	// If we already have a token, try to use it
 	if c.config.Token != "" {
 		tokenCheckData := map[string]interface{}{
@@ -177,6 +198,11 @@ func (c *Client) getToken() (string, error) {
 
 		// Make the request
 		client := &http.Client{}
+		if tlsConfig != nil {
+			client.Transport = &http.Transport{
+				TLSClientConfig: tlsConfig,
+			}
+		}
 		resp, err := client.Do(req)
 		if err != nil {
 			return "", fmt.Errorf("failed to check token validity: %w", err)
@@ -220,6 +246,11 @@ func (c *Client) getToken() (string, error) {
 
 	// Make the request
 	client := &http.Client{}
+	if tlsConfig != nil {
+		client.Transport = &http.Transport{
+			TLSClientConfig: tlsConfig,
+		}
+	}
 	resp, err := client.Do(req)
 	if err != nil {
 		return "", fmt.Errorf("failed to request new token: %w", err)
@@ -295,7 +326,16 @@ func (c *Client) establishConnection() error {
 	u.RawQuery = q.Encode()
 
 	// Connect to WebSocket
-	conn, _, err := websocket.DefaultDialer.Dial(u.String(), nil)
+	dialer := websocket.DefaultDialer
+	if c.config.TlsClientCert != "" {
+		logger.Info("Adding tls to req")
+		tlsConfig, err := loadClientCertificate(c.config.TlsClientCert)
+		if err != nil {
+			return fmt.Errorf("failed to load certificate %s: %w", c.config.TlsClientCert, err)
+		}
+		dialer.TLSClientConfig = tlsConfig
+	}
+	conn, _, err := dialer.Dial(u.String(), nil)
 	if err != nil {
 		return fmt.Errorf("failed to connect to WebSocket: %w", err)
 	}
@@ -353,3 +393,42 @@ func (c *Client) setConnected(status bool) {
 	defer c.reconnectMux.Unlock()
 	c.isConnected = status
 }
+
+// LoadClientCertificate Helper method to load client certificates
+func loadClientCertificate(p12Path string) (*tls.Config, error) {
+	logger.Info("Loading tls-client-cert %s", p12Path)
+	// Read the PKCS12 file
+	p12Data, err := os.ReadFile(p12Path)
+	if err != nil {
+		return nil, fmt.Errorf("failed to read PKCS12 file: %w", err)
+	}
+
+	// Parse PKCS12 with empty password for non-encrypted files
+	privateKey, certificate, caCerts, err := pkcs12.DecodeChain(p12Data, "")
+	if err != nil {
+		return nil, fmt.Errorf("failed to decode PKCS12: %w", err)
+	}
+
+	// Create certificate
+	cert := tls.Certificate{
+		Certificate: [][]byte{certificate.Raw},
+		PrivateKey:  privateKey,
+	}
+
+	// Optional: Add CA certificates if present
+	rootCAs, err := x509.SystemCertPool()
+	if err != nil {
+		return nil, fmt.Errorf("failed to load system cert pool: %w", err)
+	}
+	if len(caCerts) > 0 {
+		for _, caCert := range caCerts {
+			rootCAs.AddCert(caCert)
+		}
+	}
+
+	// Create TLS configuration
+	return &tls.Config{
+		Certificates: []tls.Certificate{cert},
+		RootCAs:      rootCAs,
+	}, nil
+}

websocket/config.go

@@ -54,6 +54,9 @@ func (c *Client) loadConfig() error {
 	if c.config.Secret == "" {
 		c.config.Secret = config.Secret
 	}
+	if c.config.TlsClientCert == "" {
+		c.config.TlsClientCert = config.TlsClientCert
+	}
 	if c.config.Endpoint == "" {
 		c.config.Endpoint = config.Endpoint
 		c.baseURL = config.Endpoint

websocket/types.go

@@ -1,10 +1,11 @@
 package websocket
 
 type Config struct {
-	NewtID   string `json:"newtId"`
-	Secret   string `json:"secret"`
-	Token    string `json:"token"`
-	Endpoint string `json:"endpoint"`
+	NewtID        string `json:"newtId"`
+	Secret        string `json:"secret"`
+	Token         string `json:"token"`
+	Endpoint      string `json:"endpoint"`
+	TlsClientCert string `json:"tlsClientCert"`
 }
 
 type TokenResponse struct {