cli: add -version switch to display software version

client/client.go

@@ -268,7 +268,7 @@ func Dial(ctx context.Context, options *Options, qconn quic.EarlyConnection,
 		log.Fatal().Msgf("%s", err)
 	}
 	req.Proto = "ssh3"
-	req.Header.Set("User-Agent", ssh3.GetCurrentVersion())
+	req.Header.Set("User-Agent", ssh3.GetCurrentVersionString())
 
 	var identity ssh3.Identity
 	for _, method := range options.authMethods {

cmd/ssh3-server/main.go

@@ -13,6 +13,7 @@ import (
 	"os"
 	"os/exec"
 	"path"
+	"path/filepath"
 	"sync"
 	"syscall"
 	"unsafe"
@@ -671,6 +672,7 @@ func fileExists(path string) bool {
 func main() {
 	bindAddr := flag.String("bind", "[::]:443", "the address:port pair to listen to, e.g. 0.0.0.0:443")
 	verbose := flag.Bool("v", false, "verbose mode, if set")
+	displayVersion := flag.Bool("version", false, "if set, displays the software version on standard output and exit")
 	urlPath := flag.String("url-path", "/ssh3-term", "the secret URL path on which the ssh3 server listens")
 	generateSelfSignedCert := flag.Bool("generate-selfsigned-cert", false, "if set, generates a self-self-signed cerificate and key "+
 		"that will be stored at the paths indicated by the -cert and -key args (they must not already exist)")
@@ -682,6 +684,11 @@ func main() {
 	}
 	flag.Parse()
 
+	if *displayVersion {
+		fmt.Fprintln(os.Stdout, filepath.Base(os.Args[0]), "version", ssh3.GetCurrentSoftwareVersion())
+		os.Exit(0)
+	}
+
 	if !enablePasswordLogin {
 		fmt.Fprintln(os.Stderr, "password login is disabled")
 	}
@@ -749,6 +756,8 @@ func main() {
 		log.Logger = log.Output(logFile)
 	}
 
+	log.Debug().Msgf("version %s", ssh3.GetCurrentSoftwareVersion())
+
 	quicConf := &quic.Config{
 		Allow0RTT: true,
 	}

cmd/ssh3/main.go

@@ -15,6 +15,7 @@ import (
 	"os"
 	osuser "os/user"
 	"path"
+	"path/filepath"
 	"strconv"
 	"strings"
 	"time"
@@ -266,13 +267,19 @@ func mainWithStatusCode() int {
 	issuerUrl := flag.String("use-oidc", "", "if set, force the use of OpenID Connect with the specified issuer url as parameter (it opens a browser window)")
 	oidcConfigFileName := flag.String("oidc-config", "", "OpenID Connect json config file containing the \"client_id\" and \"client_secret\" fields needed for most identity providers")
 	verbose := flag.Bool("v", false, "if set, enable verbose mode")
+	displayVersion := flag.Bool("version", false, "if set, displays the software version on standard output and exit")
 	doPKCE := flag.Bool("do-pkce", false, "if set perform PKCE challenge-response with oidc")
 	forwardSSHAgent := flag.Bool("forward-agent", false, "if set, forwards ssh agent to be used with sshv2 connections on the remote host")
 	forwardUDP := flag.String("forward-udp", "", "if set, take a localport/remoteip@remoteport forwarding localhost@localport towards remoteip@remoteport")
 	forwardTCP := flag.String("forward-tcp", "", "if set, take a localport/remoteip@remoteport forwarding localhost@localport towards remoteip@remoteport")
 	flag.Parse()
 	args := flag.Args()
 
+	if *displayVersion {
+		fmt.Fprintln(os.Stdout, filepath.Base(os.Args[0]), "version", ssh3.GetCurrentSoftwareVersion())
+		return 0
+	}
+
 	useOIDC := *issuerUrl != ""
 
 	ssh3Dir := path.Join(homedir(), ".ssh3")
@@ -285,6 +292,14 @@ func mainWithStatusCode() int {
 		util.ConfigureLogger(os.Getenv("SSH3_LOG_LEVEL"))
 	}
 
+	if len(args) == 0 {
+		log.Error().Msgf("no remote host specified, exit")
+		flag.Usage()
+		os.Exit(-1)
+	}
+
+	log.Debug().Msgf("version %s", ssh3.GetCurrentSoftwareVersion())
+
 	knownHostsPath := path.Join(ssh3Dir, "known_hosts")
 	knownHosts, skippedLines, err := ssh3.ParseKnownHosts(knownHostsPath)
 	if len(skippedLines) != 0 {

conversation.go

@@ -112,7 +112,7 @@ func (c *Conversation) EstablishClientConversation(req *http.Request, roundTripp
 	}
 
 	serverVersion := rsp.Header.Get("Server")
-	major, minor, patch, err := ParseVersion(serverVersion)
+	major, minor, patch, err := ParseVersionString(serverVersion)
 	if err != nil {
 		log.Error().Msgf("Could not parse server version: \"%s\"", serverVersion)
 		if rsp.StatusCode == 200 {

unix_server/auth.go

@@ -22,14 +22,14 @@ func HandleAuths(ctx context.Context, enablePasswordLogin bool, defaultMaxPacket
 	}
 	return func(w http.ResponseWriter, r *http.Request) {
 		defer w.(http.Flusher).Flush()
-		w.Header().Set("Server", ssh3.GetCurrentVersion())
-		major, minor, patch, err := ssh3.ParseVersion(r.UserAgent())
+		w.Header().Set("Server", ssh3.GetCurrentVersionString())
+		major, minor, patch, err := ssh3.ParseVersionString(r.UserAgent())
 		log.Debug().Msgf("received request from User-Agent %s (major %d, minor %d, patch %d)", r.UserAgent(), major, minor, patch)
 		// currently apply strict version rules
 		if err != nil || major != ssh3.MAJOR || minor != ssh3.MINOR {
 			w.WriteHeader(http.StatusForbidden)
 			if err == nil {
-				w.Write([]byte(fmt.Sprintf("Unsupported version: %d.%d.%d not supported by server in version %s", major, minor, patch, ssh3.GetCurrentVersion())))
+				w.Write([]byte(fmt.Sprintf("Unsupported version: %d.%d.%d not supported by server in version %s", major, minor, patch, ssh3.GetCurrentVersionString())))
 			} else {
 				w.Write([]byte("Unsupported user-agent"))
 			}

version.go

@@ -10,7 +10,8 @@ import (
 
 const MAJOR int = 0
 const MINOR int = 1
-const PATCH int = 3
+const PATCH int = 5
+const RC int = 3
 
 type InvalidSSHVersion struct {
 	versionString string
@@ -28,13 +29,15 @@ func (e UnsupportedSSHVersion) Error() string {
 	return fmt.Sprintf("unsupported ssh version: %s", e.versionString)
 }
 
-func GetCurrentVersion() string {
+// GetCurrentVersionString() returns the version string to be exchanged between two
+// endpoints for version negotiation
+func GetCurrentVersionString() string {
 	return fmt.Sprintf("SSH 3.0 francoismichel/ssh3 %d.%d.%d", MAJOR, MINOR, PATCH)
 }
 
-func ParseVersion(version string) (major int, minor int, patch int, err error) {
+func ParseVersionString(version string) (major int, minor int, patch int, err error) {
 	fields := strings.Fields(version)
-	if len(fields) != 4 || fields[0] != "SSH" || fields[1] != "3.0" {
+	if len(fields) < 4 || fields[0] != "SSH" || fields[1] != "3.0" {
 		log.Error().Msgf("bad SSH version fields")
 		return 0, 0, 0, InvalidSSHVersion{versionString: version}
 	}
@@ -60,3 +63,13 @@ func ParseVersion(version string) (major int, minor int, patch int, err error) {
 	}
 	return major, minor, patch, nil
 }
+
+// GetCurrentSoftwareVersion() returns the current software version to be displayed to the user
+// For version string to be communicated between endpoints, use GetCurrentVersionString() instead.
+func GetCurrentSoftwareVersion() string {
+	versionStr := fmt.Sprintf("%d.%d.%d", MAJOR, MINOR, PATCH)
+	if RC > 0 {
+		versionStr += fmt.Sprintf("-rc%d", RC)
+	}
+	return versionStr
+}