support more options

LogLevel
StrictHostKeyChecking

tssh/login.go

@@ -47,7 +47,8 @@ import (
 	"golang.org/x/term"
 )
 
-var enableDebugLogging bool
+var enableDebugLogging bool = false
+var envbleWarningLogging bool = true
 
 func debug(format string, a ...any) {
 	if !enableDebugLogging {
@@ -57,6 +58,9 @@ func debug(format string, a ...any) {
 }
 
 var warning = func(format string, a ...any) {
+	if !envbleWarningLogging {
+		return
+	}
 	fmt.Fprintf(os.Stderr, fmt.Sprintf("\033[0;33mWarning: %s\033[0m\r\n", format), a...)
 }
 
@@ -179,35 +183,37 @@ func getLoginParam(args *sshArgs) (*loginParam, error) {
 	return param, nil
 }
 
-func addHostKey(path, host string, remote net.Addr, key ssh.PublicKey) error {
-	fingerprint := ssh.FingerprintSHA256(key)
-	fmt.Fprintf(os.Stderr, "The authenticity of host '%s' can't be established.\r\n"+
-		"%s key fingerprint is %s.\r\n", host, key.Type(), fingerprint)
+func addHostKey(path, host string, remote net.Addr, key ssh.PublicKey, ask bool) error {
+	if ask {
+		fingerprint := ssh.FingerprintSHA256(key)
+		fmt.Fprintf(os.Stderr, "The authenticity of host '%s' can't be established.\r\n"+
+			"%s key fingerprint is %s.\r\n", host, key.Type(), fingerprint)
 
-	stdin, closer, err := getKeyboardInput()
-	if err != nil {
-		return err
-	}
-	defer closer()
-
-	reader := bufio.NewReader(stdin)
-	fmt.Fprintf(os.Stderr, "Are you sure you want to continue connecting (yes/no/[fingerprint])? ")
-	for {
-		input, err := reader.ReadString('\n')
+		stdin, closer, err := getKeyboardInput()
 		if err != nil {
 			return err
 		}
-		input = strings.TrimSpace(input)
-		if input == fingerprint {
-			break
-		}
-		input = strings.ToLower(input)
-		if input == "yes" {
-			break
-		} else if input == "no" {
-			return fmt.Errorf("host key not trusted")
+		defer closer()
+
+		reader := bufio.NewReader(stdin)
+		fmt.Fprintf(os.Stderr, "Are you sure you want to continue connecting (yes/no/[fingerprint])? ")
+		for {
+			input, err := reader.ReadString('\n')
+			if err != nil {
+				return err
+			}
+			input = strings.TrimSpace(input)
+			if input == fingerprint {
+				break
+			}
+			input = strings.ToLower(input)
+			if input == "yes" {
+				break
+			} else if input == "no" {
+				return fmt.Errorf("host key not trusted")
+			}
+			fmt.Fprintf(os.Stderr, "Please type 'yes', 'no' or the fingerprint: ")
 		}
-		fmt.Fprintf(os.Stderr, "Please type 'yes', 'no' or the fingerprint: ")
 	}
 
 	writeKnownHost := func() error {
@@ -219,7 +225,7 @@ func addHostKey(path, host string, remote net.Addr, key ssh.PublicKey) error {
 		return knownhosts.WriteKnownHost(file, host, remote, key)
 	}
 
-	if err = writeKnownHost(); err != nil {
+	if err := writeKnownHost(); err != nil {
 		warning("Failed to add the host to the list of known hosts (%s): %v", path, err)
 		return nil
 	}
@@ -266,6 +272,7 @@ func getHostKeyCallback(args *sshArgs) (ssh.HostKeyCallback, knownhosts.HostKeyC
 
 	cb := func(host string, remote net.Addr, key ssh.PublicKey) error {
 		err := kh(host, remote, key)
+		strictHostKeyChecking := strings.ToLower(getOptionConfig(args, "StrictHostKeyChecking"))
 		if knownhosts.IsHostKeyChanged(err) {
 			path := primaryPath
 			if path == "" {
@@ -282,11 +289,22 @@ func getHostKeyCallback(args *sshArgs) (ssh.HostKeyCallback, knownhosts.HostKeyC
 				"Please contact your system administrator.\r\n"+
 				"Add correct host key in %s to get rid of this message.\r\n",
 				key.Type(), ssh.FingerprintSHA256(key), path)
-			return err
 		} else if knownhosts.IsHostUnknown(err) && primaryPath != "" {
-			return addHostKey(primaryPath, host, remote, key)
+			ask := true
+			switch strictHostKeyChecking {
+			case "yes":
+				return err
+			case "accept-new", "no", "off":
+				ask = false
+			}
+			return addHostKey(primaryPath, host, remote, key, ask)
+		}
+		switch strictHostKeyChecking {
+		case "no", "off":
+			return nil
+		default:
+			return err
 		}
-		return err
 	}
 
 	return cb, kh, err
@@ -700,12 +718,43 @@ func (c *connWithTimeout) Read(b []byte) (n int, err error) {
 	return
 }
 
+func setupLogLevel(args *sshArgs) func() {
+	previousDebug := enableDebugLogging
+	previousWarning := envbleWarningLogging
+	reset := func() {
+		enableDebugLogging = previousDebug
+		envbleWarningLogging = previousWarning
+	}
+	if args.Debug {
+		enableDebugLogging = true
+		envbleWarningLogging = true
+		return reset
+	}
+	switch strings.ToLower(getOptionConfig(args, "LogLevel")) {
+	case "quiet", "fatal", "error":
+		enableDebugLogging = false
+		envbleWarningLogging = false
+	case "debug", "debug1", "debug2", "debug3":
+		enableDebugLogging = true
+		envbleWarningLogging = true
+	case "info", "verbose":
+		fallthrough
+	default:
+		enableDebugLogging = false
+		envbleWarningLogging = true
+	}
+	return reset
+}
+
 func sshConnect(args *sshArgs, client *ssh.Client, proxy string) (*ssh.Client, bool, error) {
 	param, err := getLoginParam(args)
 	if err != nil {
 		return nil, false, err
 	}
 
+	resetLogLevel := setupLogLevel(args)
+	defer resetLogLevel()
+
 	if client := connectViaControl(args, param); client != nil {
 		return client, true, nil
 	}