Add key generation section

Add note saying weblug should not be run on the open internet without a
reverse proxy.

.gitignore

@@ -25,3 +25,7 @@ vendor/
 # Go workspace file
 go.work
 
+# Possible key and cert files
+*.key
+*.pem
+*.cert

Makefile

@@ -10,4 +10,5 @@ static: cmd/weblug/*.go
 	CGO_ENABLED=0 go build -ldflags="-w -s" -o weblug $^
 
 test: weblug
+	go test ./...
 	sudo bash -c "cd test && ./blackbox.sh"

README.md

@@ -16,20 +16,26 @@ Webooks are defined via a yaml file. See [weblug.yml](weblug.yml) for an example
 
 ### Caveats
 
-1. `weblug` does not support https encryption
+1. `weblug` should not face the open internet
 
-weblug is expected to run behind a http reverse proxy (e.g. `apache` or `nginx`) which handles transport encryption. The program it self does not support https, nor are there any plans to implement this in the near future.
+weblug is expected to run behind a http reverse proxy (e.g. `apache` or `nginx`).
+While the program itself does support tls, to avoid a whole class of security issues, `weblug` should never run on the open internet without a http reverse proxy.
 
-CAVE: Don't expose secrets and credentials by running this without any transport encryption!
-
-2. Do not run this without reverse proxy
-
-`weblug` relies on the standart go http implementation. To avoid a whole class of security issues, `weblug` should never run on the open internet without a http reverse proxy.
-
-3. `weblug` runs as root, when using custom UID/GIDs
+2. `weblug` runs as root, when using custom UID/GIDs
 
 In it's current implementation, `weblug` requires to remain running as root without dropping privileges when using custom UID/GIDs.
 
+### TLS
+
+`weblug` now supports tls. To generate self-signed keys
+
+```
+openssl genrsa -out weblug.key 2048
+openssl req -new -x509 -sha256 -key weblug.key -out weblug1.pem -days 365
+```
+
+Then configure the `weblug.yml` file accordingly. You can use multiple keys/certificates.
+
 ## Build
 
     make               # Build weblug

Taskfile.yml

@@ -29,4 +29,13 @@ tasks:
     preconditions:
       - test -f weblug
     cmds:
+      - go test ./...
       - sudo bash -c "cd test && ./blackbox.sh"
+  vet:
+    cmds:
+      - go vet ./...
+  certs:
+    cmds:
+      - openssl genrsa -out weblug.key 2048
+      - openssl req -new -x509 -sha256 -key weblug.key -subj "/C=XX/ST=None/L=Nirwana/O=Adeptus Mechanicus/OU=Cult Mechanicus/CN=example1.local" -addext "subjectAltName = DNS:example1.local" -out weblug1.pem -days 365
+      - openssl req -new -x509 -sha256 -key weblug.key -subj "/C=XX/ST=None/L=Nirwana/O=Adeptus Mechanicus/OU=Cult Mechanicus/CN=example1.local" -addext "subjectAltName = DNS:example1.local" -out weblug2.pem -days 365

cmd/weblug/config.go

@@ -1,24 +1,40 @@
 package main
 
 import (
+	"crypto/tls"
 	"fmt"
 	"io/ioutil"
 
 	"gopkg.in/yaml.v2"
 )
 
+var cf Config
+
 type Config struct {
 	Settings ConfigSettings `yaml:"settings"`
 	Hooks    []Hook         `yaml:"hooks"`
 }
 
 type ConfigSettings struct {
-	BindAddress    string `yaml:"bind"`          // Bind address for the webserver
-	UID            int    `yaml:"uid"`           // Custom user ID or 0, if not being used
-	GID            int    `yaml:"gid"`           // Custom group ID or 0, if not being used
-	ReadTimeout    int    `yaml:"readtimeout"`   // Timeout for reading the whole request
-	WriteTimeout   int    `yaml:"writetimeout"`  // Timeout for writing the whole response
-	MaxHeaderBytes int    `yaml:"maxheadersize"` // Maximum size of the receive body
+	BindAddress    string      `yaml:"bind"`          // Bind address for the webserver
+	UID            int         `yaml:"uid"`           // Custom user ID or 0, if not being used
+	GID            int         `yaml:"gid"`           // Custom group ID or 0, if not being used
+	ReadTimeout    int         `yaml:"readtimeout"`   // Timeout for reading the whole request
+	WriteTimeout   int         `yaml:"writetimeout"`  // Timeout for writing the whole response
+	MaxHeaderBytes int         `yaml:"maxheadersize"` // Maximum size of the receive body
+	TLS            TLSSettings `yaml:"tls"`
+}
+
+type TLSSettings struct {
+	Enabled    bool          `yaml:"enabled"`
+	MinVersion string        `yaml:"minversion"`
+	MaxVersion string        `yaml:"maxversion"`
+	Keypairs   []TLSKeypairs `yaml:"keypairs"`
+}
+
+type TLSKeypairs struct {
+	Keyfile     string `yaml:"keyfile"`
+	Certificate string `yaml:"certificate"`
 }
 
 func (cf *Config) SetDefaults() {
@@ -63,3 +79,19 @@ func (cf *Config) LoadYAML(filename string) error {
 	}
 	return cf.Check()
 }
+
+func ParseTLSVersion(version string) (uint16, error) {
+	if version == "" {
+		return tls.VersionTLS12, nil
+	} else if version == "1.3" {
+		return tls.VersionTLS13, nil
+	} else if version == "1.2" {
+		return tls.VersionTLS12, nil
+	} else if version == "1.1" {
+		return tls.VersionTLS11, nil
+	} else if version == "1.0" {
+		return tls.VersionTLS10, nil
+	} else {
+		return 0, fmt.Errorf("invalid tls version string")
+	}
+}

cmd/weblug/hook.go

@@ -12,6 +12,7 @@ import (
 type Hook struct {
 	Name             string            `yaml:"name"`        // name of the hook
 	Route            string            `yaml:"route"`       // http route
+	Hosts            []string          `yaml:"hosts"`       // allowed remote hosts
 	Command          string            `yaml:"command"`     // Actual command to execute
 	Background       bool              `yaml:"background"`  // Run in background
 	Concurrency      int               `yaml:"concurrency"` // Number of allowed concurrent runs
@@ -80,6 +81,10 @@ func cmdSplit(command string) []string {
 
 // Run executes the given command and return it's return code. It also respects the given concurrency number and will block until resources are free
 func (hook *Hook) Run() error {
+	if hook.Command == "" {
+		return nil
+	}
+
 	split := cmdSplit(hook.Command)
 	args := make([]string, 0)
 	if len(split) > 1 {

cmd/weblug/weblug.go

@@ -4,17 +4,18 @@
 package main
 
 import (
+	"crypto/tls"
 	"fmt"
 	"log"
+	"net"
 	"net/http"
 	"os"
 	"os/signal"
+	"strings"
 	"syscall"
 	"time"
 )
 
-var cf Config
-
 type Handler func(http.ResponseWriter, *http.Request)
 
 func usage() {
@@ -56,6 +57,20 @@ func sanityCheckHooks(hooks []Hook) error {
 	return nil
 }
 
+// Extract the hostname from an URL
+func hostname(url string) string {
+	hostname := url
+	i := strings.Index(hostname, "://")
+	if i > 0 {
+		hostname = hostname[i+3:]
+	}
+	i = strings.Index(hostname, ":")
+	if i > 0 {
+		hostname = hostname[:i]
+	}
+	return hostname
+}
+
 func main() {
 	cf.SetDefaults()
 	if len(os.Args) < 2 {
@@ -100,38 +115,118 @@ func main() {
 		}
 	}
 
-	// Create default handlers
-	http.HandleFunc("/health", createHealthHandler())
-	http.HandleFunc("/health.json", createHealthHandler())
-	http.HandleFunc("/index", createDefaultHandler())
-	http.HandleFunc("/index.htm", createDefaultHandler())
-	http.HandleFunc("/index.html", createDefaultHandler())
-	http.HandleFunc("/robots.txt", createRobotsHandler())
-
-	// Register hooks
+	server := CreateWebserver(cf)
+	mux := http.NewServeMux()
+	server.Handler = mux
+	if err := RegisterHandlers(cf, mux); err != nil {
+		fmt.Fprintf(os.Stderr, "error: %s\n", err)
+		os.Exit(1)
+	}
 	for i, hook := range cf.Hooks {
-		if hook.Route == "" {
-			fmt.Fprintf(os.Stderr, "Invalid hook %s: No route defined\n", hook.Name)
-		}
-		if hook.Concurrency < 1 {
-			hook.Concurrency = 1
-		}
 		log.Printf("Webhook %d: '%s' [%s] \"%s\"\n", i, hook.Name, hook.Route, hook.Command)
-		http.HandleFunc(hook.Route, createHandler(hook))
 	}
 
 	awaitTerminationSignal()
 
-	log.Printf("Launching webserver on %s", cf.Settings.BindAddress)
+	var listener net.Listener
+	var err error
+	if cf.Settings.TLS.Enabled {
+		log.Printf("Launching tls webserver on %s", cf.Settings.BindAddress)
+		listener, err = CreateTLSListener(cf)
+		if err != nil {
+			fmt.Fprintf(os.Stderr, "error: %s\n", err)
+			os.Exit(1)
+		}
+	} else {
+		log.Printf("Launching webserver on %s", cf.Settings.BindAddress)
+		listener, err = CreateListener(cf)
+		if err != nil {
+			fmt.Fprintf(os.Stderr, "error: %s\n", err)
+			os.Exit(1)
+		}
+	}
+	server.Serve(listener)
+
+	// read guard, should never ever ever be called.
+	// If we end up here, the only safe thing we can do is terminate the program
+	panic("unexpected end of main loop")
+}
+
+func CreateListener(cf Config) (net.Listener, error) {
+	return net.Listen("tcp", cf.Settings.BindAddress)
+}
+
+func CreateTLSListener(cf Config) (net.Listener, error) {
+	var err error
+	tlsConfig := &tls.Config{
+		MinVersion: tls.VersionTLS12,
+	}
+	if cf.Settings.TLS.MinVersion != "" {
+		tlsConfig.MinVersion, err = ParseTLSVersion(cf.Settings.TLS.MinVersion)
+		if err != nil {
+			return nil, fmt.Errorf("invalid tls min version")
+		}
+	}
+	if cf.Settings.TLS.MaxVersion != "" {
+		tlsConfig.MaxVersion, err = ParseTLSVersion(cf.Settings.TLS.MaxVersion)
+		if err != nil {
+			return nil, fmt.Errorf("invalid tls max version")
+		}
+	}
+	if tlsConfig.MinVersion == tls.VersionTLS10 || tlsConfig.MinVersion == tls.VersionTLS11 {
+		fmt.Fprintf(os.Stderr, "warning: using of a deprecated TLS version (< 1.2) is not recommended\n")
+	}
+
+	// Create self-signed certificate, when no keyfile and no certificates are present
+	if len(cf.Settings.TLS.Keypairs) == 0 {
+		return nil, fmt.Errorf("no keypairs provided")
+	} else {
+		// Load key/certificates keypairs
+		tlsConfig.Certificates = make([]tls.Certificate, len(cf.Settings.TLS.Keypairs))
+		for i, keypair := range cf.Settings.TLS.Keypairs {
+			tlsConfig.Certificates[i], err = tls.LoadX509KeyPair(keypair.Certificate, keypair.Keyfile)
+			if err != nil {
+				return nil, fmt.Errorf("invalid tls keypair '%s,%s' - %s", keypair.Certificate, keypair.Keyfile, err)
+			}
+		}
+
+		if len(tlsConfig.Certificates) == 1 {
+			log.Printf("Loaded 1 tls certificate")
+		} else {
+			log.Printf("Loaded %d tls certificates", len(tlsConfig.Certificates))
+		}
+	}
+	return tls.Listen("tcp", cf.Settings.BindAddress, tlsConfig)
+}
+
+func CreateWebserver(cf Config) *http.Server {
 	server := &http.Server{
 		Addr:           cf.Settings.BindAddress,
 		ReadTimeout:    time.Duration(cf.Settings.ReadTimeout) * time.Second,
 		WriteTimeout:   time.Duration(cf.Settings.WriteTimeout) * time.Second,
 		MaxHeaderBytes: cf.Settings.MaxHeaderBytes,
 	}
-	err := server.ListenAndServe()
-	log.Fatal(err)
-	os.Exit(1)
+	return server
+}
+
+func RegisterHandlers(cf Config, mux *http.ServeMux) error {
+	// Register default paths
+	mux.HandleFunc("/", createDefaultHandler())
+	mux.HandleFunc("/health", createHealthHandler())
+	mux.HandleFunc("/health.json", createHealthHandler())
+	mux.HandleFunc("/robots.txt", createRobotsHandler())
+
+	// Register hooks
+	for _, hook := range cf.Hooks {
+		if hook.Route == "" {
+			return fmt.Errorf("no route defined in hook %s", hook.Name)
+		}
+		if hook.Concurrency < 1 {
+			hook.Concurrency = 1
+		}
+		mux.HandleFunc(hook.Route, createHandler(hook))
+	}
+	return nil
 }
 
 // create a http handler function from the given hook
@@ -139,6 +234,25 @@ func createHandler(hook Hook) Handler {
 	return func(w http.ResponseWriter, r *http.Request) {
 		log.Printf("GET %s %s", r.RemoteAddr, hook.Name)
 
+		// Check if this hook is remote-host limited
+		if len(hook.Hosts) > 0 {
+			allowed := false
+			// Extract the queried hostname
+			queriedHost := hostname(r.Host)
+			for _, host := range hook.Hosts {
+				if host == queriedHost {
+					allowed = true
+					break
+				}
+			}
+
+			if !allowed {
+				// Hook doesn't exist for this host.
+				respondNotFound(w, r)
+				return
+			}
+		}
+
 		// Check if adresses are allowed or blocked
 		allowed, err := hook.IsAddressAllowed(r.RemoteAddr)
 		if err != nil {
@@ -223,8 +337,15 @@ func createHealthHandler() Handler {
 
 func createDefaultHandler() Handler {
 	return func(w http.ResponseWriter, r *http.Request) {
-		w.WriteHeader(200)
-		fmt.Fprintf(w, "weblug - webhook receiver program\nSee https://codeberg.org/grisu48/weblug\n")
+		if r.URL.Path == "/" || r.URL.Path == "/index.txt" {
+			w.WriteHeader(200)
+			fmt.Fprintf(w, "weblug - webhook receiver program\nhttps://codeberg.org/grisu48/weblug\n")
+		} else if r.URL.Path == "/index.htm" || r.URL.Path == "/index.html" {
+			w.WriteHeader(200)
+			fmt.Fprintf(w, "<!DOCTYPE html><html><head><title>weblug</title></head>\n<body><p><a href=\"https://codeberg.org/grisu48/weblug\">weblug</a> - webhook receiver program</p>\n</body></html>")
+		} else {
+			respondNotFound(w, r)
+		}
 	}
 }
 
@@ -234,3 +355,9 @@ func createRobotsHandler() Handler {
 		fmt.Fprintf(w, "User-agent: *\nDisallow: /")
 	}
 }
+
+func respondNotFound(w http.ResponseWriter, r *http.Request) error {
+	w.WriteHeader(404)
+	_, err := fmt.Fprintf(w, "not found\n")
+	return err
+}

cmd/weblug/weblug_test.go

@@ -0,0 +1,343 @@
+package main
+
+import (
+	"context"
+	"crypto/rand"
+	"crypto/rsa"
+	"crypto/tls"
+	"crypto/x509"
+	"crypto/x509/pkix"
+	"encoding/pem"
+	"fmt"
+	"io"
+	"math/big"
+	"net"
+	"net/http"
+	"os"
+	"strings"
+	"testing"
+	"time"
+)
+
+func TestMain(m *testing.M) {
+	// Run tests
+	ret := m.Run()
+	os.Exit(ret)
+}
+
+// Test the general webserver functionalities
+func TestWebserver(t *testing.T) {
+	var cf Config
+
+	cf.Settings.BindAddress = "127.0.0.1:2088"
+	cf.Hooks = make([]Hook, 0)
+	cf.Hooks = append(cf.Hooks, Hook{Route: "/test1", Name: "test1", Command: ""})
+	cf.Hooks = append(cf.Hooks, Hook{Route: "/test2", Name: "test2", Command: ""})
+
+	listener, err := CreateListener(cf)
+	if err != nil {
+		t.Fatalf("error creating listener: %s", err)
+		return
+	}
+	server := CreateWebserver(cf)
+	mux := http.NewServeMux()
+	server.Handler = mux
+	if err := RegisterHandlers(cf, mux); err != nil {
+		t.Fatalf("error registering handlers: %s", err)
+		return
+	}
+	go server.Serve(listener)
+	defer func() {
+		if err := server.Shutdown(context.Background()); err != nil {
+			t.Fatalf("error while server shutdown: %s", err)
+			return
+		}
+	}()
+
+	assertStatusCode := func(url string, statusCode int) {
+		resp, err := http.Get(url)
+		if err != nil {
+			t.Fatalf("%s", err)
+			return
+		}
+		if resp.StatusCode != statusCode {
+			t.Fatalf("GET / returns status code %d != %d", resp.StatusCode, statusCode)
+		}
+	}
+
+	// Check default sites
+	assertStatusCode(fmt.Sprintf("http://%s/", cf.Settings.BindAddress), http.StatusOK)
+	assertStatusCode(fmt.Sprintf("http://%s/health", cf.Settings.BindAddress), http.StatusOK)
+	assertStatusCode(fmt.Sprintf("http://%s/health.json", cf.Settings.BindAddress), http.StatusOK)
+	assertStatusCode(fmt.Sprintf("http://%s/robots.txt", cf.Settings.BindAddress), http.StatusOK)
+	// Check for a 404 page
+	assertStatusCode(fmt.Sprintf("http://%s/404", cf.Settings.BindAddress), http.StatusNotFound)
+	assertStatusCode(fmt.Sprintf("http://%s/test3", cf.Settings.BindAddress), http.StatusNotFound)
+	// Test registered hooks
+	assertStatusCode(fmt.Sprintf("http://%s/test1", cf.Settings.BindAddress), http.StatusOK)
+	assertStatusCode(fmt.Sprintf("http://%s/test2", cf.Settings.BindAddress), http.StatusOK)
+}
+
+// Tests the TLS functions of the webserver
+func TestTLSWebserver(t *testing.T) {
+	var cf Config
+
+	const TESTPORT = 2089
+
+	// Test keypairs. testkey1 belongs to the "localhost" host and testkey2 belongs to the "localhost" and "example.com" hosts
+	keypairs := make([]TLSKeypairs, 0)
+	keypairs = append(keypairs, TLSKeypairs{Keyfile: "testkey1.pem", Certificate: "testcert1.pem"})
+	keypairs = append(keypairs, TLSKeypairs{Keyfile: "testkey2.pem", Certificate: "testcert2.pem"})
+
+	// Generate test certificates
+	for i, keypair := range keypairs {
+		if fileExists(keypair.Keyfile) {
+			t.Fatalf("test key '%s' already exists", keypair.Keyfile)
+			return
+		}
+		if fileExists(keypair.Certificate) {
+			t.Fatalf("test certificate '%s' already exists", keypair.Certificate)
+			return
+		}
+
+		hostnames := []string{"localhost"}
+		if i == 1 {
+			hostnames = append(hostnames, "example.com")
+		}
+		if err := generateKeypair(keypair.Keyfile, keypair.Certificate, hostnames); err != nil {
+			t.Fatalf("keypair generation failed: %s\n", err)
+			return
+		}
+
+		defer func(keypair TLSKeypairs) {
+			os.Remove(keypair.Keyfile)
+			os.Remove(keypair.Certificate)
+		}(keypair)
+	}
+
+	cf.Settings.BindAddress = fmt.Sprintf("localhost:%d", TESTPORT)
+	cf.Settings.TLS.Enabled = true
+	cf.Settings.TLS.MinVersion = "1.3"
+	cf.Settings.TLS.MaxVersion = "1.3"
+	cf.Settings.TLS.Keypairs = keypairs
+	cf.Hooks = make([]Hook, 0)
+	cf.Hooks = append(cf.Hooks, Hook{Route: "/test1", Name: "test1", Command: "", Hosts: []string{"localhost"}})
+	cf.Hooks = append(cf.Hooks, Hook{Route: "/test2", Name: "test2", Command: "", Hosts: []string{"localhost", "example.com"}})
+
+	// Setup TLS webserver
+	listener, err := CreateTLSListener(cf)
+	if err != nil {
+		t.Fatalf("error creating tls listener: %s", err)
+		return
+	}
+	server := CreateWebserver(cf)
+	mux := http.NewServeMux()
+	server.Handler = mux
+	if err := RegisterHandlers(cf, mux); err != nil {
+		t.Fatalf("error registering handlers: %s", err)
+		return
+	}
+	go server.Serve(listener)
+	defer func() {
+		if err := server.Shutdown(context.Background()); err != nil {
+			t.Fatalf("error while server shutdown: %s", err)
+			return
+		}
+	}()
+
+	// Default page without https should return a 400 error
+	resp, err := http.Get(fmt.Sprintf("http://%s/", cf.Settings.BindAddress))
+	if err != nil {
+		t.Fatalf("%s", err)
+		return
+	}
+	if resp.StatusCode != http.StatusBadRequest {
+		t.Fatalf("GET / returns status code %d for default page (400 expected)", resp.StatusCode)
+	}
+
+	// Check default page with tls certificates
+	certs := make([]tls.Certificate, 0)
+	rootCAs, _ := x509.SystemCertPool()
+	for i, keypair := range keypairs {
+		x509cert, err := readCertificate(keypair.Certificate)
+		if err != nil {
+			t.Fatalf("error loading certificate %d: %s", i, err)
+			return
+		}
+		raw := make([][]byte, 0)
+		raw = append(raw, x509cert.Raw)
+		certs = append(certs, tls.Certificate{Certificate: raw})
+		rootCAs.AddCert(x509cert)
+	}
+
+	dialer := &net.Dialer{}
+	transport := &http.Transport{
+		TLSClientConfig: &tls.Config{
+			Certificates: certs,
+			RootCAs:      rootCAs,
+		},
+		// Mock connections to example.com -> 127.0.0.1
+		DialContext: func(ctx context.Context, network, addr string) (net.Conn, error) {
+			if strings.Contains(addr, "example.com") {
+				addr = strings.ReplaceAll(addr, "example.com", "127.0.0.1")
+			}
+			return dialer.DialContext(ctx, network, addr)
+		},
+	}
+	client := http.Client{Transport: transport, Timeout: 15 * time.Second}
+
+	assertStatusCode := func(url string, statusCode int) {
+		resp, err = client.Get(url)
+		if err != nil {
+			t.Fatalf("%s", err)
+			return
+		}
+		if resp.StatusCode != statusCode {
+			t.Fatalf("GET / returns status code %d != %d", resp.StatusCode, statusCode)
+		}
+	}
+	fetchBody := func(url string) (string, error) {
+		resp, err = client.Get(url)
+		if err != nil {
+			return "", err
+		}
+		body, err := io.ReadAll(resp.Body)
+		return string(body), err
+	}
+
+	// Check default page and test hooks
+	assertStatusCode(fmt.Sprintf("https://%s/", cf.Settings.BindAddress), http.StatusOK)
+	assertStatusCode(fmt.Sprintf("https://%s/test1", cf.Settings.BindAddress), http.StatusOK)
+	assertStatusCode(fmt.Sprintf("https://%s/test2", cf.Settings.BindAddress), http.StatusOK)
+	assertStatusCode(fmt.Sprintf("https://%s/test404", cf.Settings.BindAddress), http.StatusNotFound)
+
+	// Check if connection via TLS 1.2 is not accepted (we're enforcing TLS >= 1.3)
+	transport.TLSClientConfig.MinVersion = tls.VersionTLS12
+	transport.TLSClientConfig.MaxVersion = tls.VersionTLS12
+	resp, err = client.Get(fmt.Sprintf("https://%s/", cf.Settings.BindAddress))
+	if err == nil {
+		t.Fatal("tls 1.2 connection possible where it should be unsupported", err)
+		return
+	} else {
+		// TODO: Matching by string might be flanky.
+		if !strings.Contains(err.Error(), "tls: protocol version not supported") {
+			t.Fatalf("%s", err)
+			return
+		}
+	}
+	transport.TLSClientConfig.MaxVersion = tls.VersionTLS13
+
+	// Check if example.com resolves (second certificate)
+	assertStatusCode(fmt.Sprintf("https://example.com:%d/", TESTPORT), http.StatusOK)
+	// Only /test2 should be reachable via example.com
+	assertStatusCode(fmt.Sprintf("https://example.com:%d/test1", TESTPORT), http.StatusNotFound)
+	assertStatusCode(fmt.Sprintf("https://example.com:%d/test2", TESTPORT), http.StatusOK)
+
+	// Assert, that the host 404 page is the same as the 404 page for a route that doesn't exist.
+	// This check is needed, because we pretend a path to not exist, if `hosts` is configured and
+	// we don't want to give attackers the possibility to distinguish between the two 404 errors
+	if body1, err := fetchBody(fmt.Sprintf("https://%s/test404", cf.Settings.BindAddress)); err != nil {
+		t.Fatalf("%s", err)
+		return
+	} else if body2, err := fetchBody(fmt.Sprintf("https://example.com:%d/test1", TESTPORT)); err != nil {
+		t.Fatalf("%s", err)
+		return
+	} else {
+		if body1 != body2 {
+			t.Fatal("404 bodies differ between default 404 page and host-not-matched route", err)
+			return
+		}
+	}
+}
+
+func generateKeypair(keyfile string, certfile string, hostnames []string) error {
+	key, err := rsa.GenerateKey(rand.Reader, 2048)
+	if err != nil {
+		return err
+	}
+
+	// Write key to file
+	var buffer []byte = x509.MarshalPKCS1PrivateKey(key)
+	block := &pem.Block{
+		Type:  "RSA PRIVATE KEY",
+		Bytes: buffer,
+	}
+	file, err := os.Create(keyfile)
+	if err != nil {
+		return err
+	}
+	defer file.Close()
+	if err := file.Chmod(os.FileMode(0400)); err != nil {
+		return err
+	}
+	if err = pem.Encode(file, block); err != nil {
+		return err
+	}
+	if err := file.Close(); err != nil {
+		return err
+	}
+
+	// Generate certificate
+	notBefore := time.Now()
+	notAfter := notBefore.Add(365 * 24 * 10 * time.Hour)
+
+	//Create certificate templet
+	template := x509.Certificate{
+		SerialNumber:          big.NewInt(0),
+		Subject:               pkix.Name{CommonName: hostnames[0]},
+		SignatureAlgorithm:    x509.SHA256WithRSA,
+		DNSNames:              hostnames,
+		NotBefore:             notBefore,
+		NotAfter:              notAfter,
+		BasicConstraintsValid: true,
+		KeyUsage:              x509.KeyUsageDigitalSignature | x509.KeyUsageKeyAgreement | x509.KeyUsageKeyEncipherment | x509.KeyUsageDataEncipherment,
+		ExtKeyUsage:           []x509.ExtKeyUsage{x509.ExtKeyUsageServerAuth, x509.ExtKeyUsageClientAuth},
+	}
+	//Create certificate using templet
+	cert, err := x509.CreateCertificate(rand.Reader, &template, &template, &key.PublicKey, key)
+	if err != nil {
+		return err
+	}
+	block = &pem.Block{
+		Type:  "CERTIFICATE",
+		Bytes: cert,
+	}
+
+	file, err = os.Create(certfile)
+	if err != nil {
+		return err
+	}
+	defer file.Close()
+	if err := file.Chmod(os.FileMode(0644)); err != nil {
+		return err
+	}
+	if err = pem.Encode(file, block); err != nil {
+		return err
+	}
+	if err := file.Close(); err != nil {
+		return err
+	}
+	return nil
+}
+
+func readCertificate(certfile string) (*x509.Certificate, error) {
+	buffer, err := os.ReadFile(certfile)
+	if err != nil {
+		return nil, err
+	}
+	p, _ := pem.Decode(buffer)
+	if p == nil {
+		return nil, fmt.Errorf("invalid pem file")
+	}
+	cert, err := x509.ParseCertificate(p.Bytes)
+	return cert, err
+
+}
+
+func fileExists(filename string) bool {
+	st, err := os.Stat(filename)
+	if err != nil {
+		return false
+	}
+	return !st.IsDir()
+}

doc/weblug.8

@@ -50,6 +50,29 @@ See the following example configuration file:
 .br
 .B "  gid: 0                     # run under specified group id
 .br
+.B "  # Enable TLS here here
+.br
+.B "  tls:
+.br
+.B "    enabled: true
+.br
+.B "    # Minimum and maximum required TLS version. By default TLS1.2 is the minimum
+.br
+.B "    minversion: '1.2'
+.br
+.B "    maxversion: ''
+.br
+.B "    keypairs:
+.br
+.B "      - keyfile: 'weblug.key'
+.br
+.B "        certificate: 'weblug1.pem'
+.br
+.B "      - keyfile: 'weblug.key'
+.br
+.B "        certificate: 'weblug2.pem'
+.br
+.br
 .B "# hook definitions. A hook needs to define the HTTP endpoint ("route") and the command
 .br
 .B "# See the following examples for more possible options.
@@ -60,6 +83,16 @@ See the following example configuration file:
 .br
 .B "    route: "/webhooks/1"
 .br
+.B "    # if hosts is present, then limit the incoming requests to the given remote host(s)
+.br
+.B "    # Currently multiplexing the same route to different hosts does not work
+.br
+.B "    hosts:
+.br
+.B "      - example1.local
+.br
+.B "      - example2.local
+.br
 .B "    command: "sleep 5"
 .br
 .B "    background: True         # Terminate http request immediately

weblug.yml

@@ -11,12 +11,31 @@ settings:
   readtimeout: 10            # if set, maximum number of seconds to receive the full request
   writetimeout: 10           # if set, maximum number of seconds to send the full response
   maxheadersize: 4096        # maximum header size
+  # Enable TLS
+  # Note that it is not recommended to run weblug on the open internet without using a reverse proxy
+  tls:
+    enabled: false
+    # Minimum and maximum required TLS version. By default TLS1.2 is the minimum
+    minversion: '1.2'
+    maxversion: ''
+    keypairs:
+      - keyfile: 'weblug.key'
+        certificate: 'weblug1.pem'
+      - keyfile: 'weblug.key'
+        certificate: 'weblug2.pem'
 
 # hook definitions. A hook needs to define the HTTP endpoint ("route") and the command
 # See the following examples for more possible options.
 hooks:
   - name: 'hook one'
     route: "/webhooks/1"
+
+    # if hosts is present, then limit the incoming requests to the given remote host(s)
+    # Currently multiplexing the same route to different hosts does not work
+    hosts:
+      - example1.local
+      - example2.local
+    
     command: "sleep 5"
     background: True         # Terminate http request immediately
     concurrency: 2           # At most 2 parallel processes are allowed