Replace Python launcher with native Go UI

main.go

@@ -6,6 +6,7 @@ import (
 	"crypto/tls"
 	"flag"
 	"fmt"
+	"io"
 	"log"
 	"net"
 	"net/http"
@@ -74,6 +75,7 @@ func main() {
 	server := flag.String("server", "localhost:64738", "the server to connect to")
 	username := flag.String("username", "", "the username of the client")
 	password := flag.String("password", "", "the password of the server")
+	passwordFile := flag.String("password-file", "", "read the server password from a file")
 	insecure := flag.Bool("insecure", false, "skip server certificate verification")
 	certificate := flag.String("certificate", "", "PEM encoded certificate and private key")
 	cfgfn := flag.String("config", "~/.barnard.toml", "Path to TOML formatted configuration file")
@@ -229,7 +231,11 @@ func main() {
 	b.NoiseSuppressor.SetEnabled(enabled)
 
 	b.Config.Username = *username
-	b.Config.Password = *password
+	resolvedPassword, err := resolve_password(*password, *passwordFile)
+	if err != nil {
+		handle_raw_error(err)
+	}
+	b.Config.Password = resolvedPassword
 
 	if *insecure {
 		b.TLSConfig.InsecureSkipVerify = true
@@ -255,6 +261,40 @@ func main() {
 	handle_error(&b)
 }
 
+func resolve_password(password, passwordFile string) (string, error) {
+	if passwordFile == "" {
+		return password, nil
+	}
+	if password != "" {
+		return "", fmt.Errorf("password and password-file cannot be used together")
+	}
+	file, err := os.Open(passwordFile)
+	if err != nil {
+		return "", fmt.Errorf("read password file: %w", err)
+	}
+	defer file.Close()
+	info, err := file.Stat()
+	if err != nil {
+		return "", fmt.Errorf("inspect password file: %w", err)
+	}
+	if !info.Mode().IsRegular() {
+		return "", fmt.Errorf("password file must be a regular file")
+	}
+	const maximumPasswordFileSize = 4096
+	contents, err := io.ReadAll(io.LimitReader(file, maximumPasswordFileSize+1))
+	if err != nil {
+		return "", fmt.Errorf("read password file: %w", err)
+	}
+	if len(contents) > maximumPasswordFileSize {
+		return "", fmt.Errorf("password file is too large")
+	}
+	contents = []byte(strings.TrimSuffix(strings.TrimSuffix(string(contents), "\n"), "\r"))
+	if strings.ContainsAny(string(contents), "\r\n") {
+		return "", fmt.Errorf("password file must contain exactly one line")
+	}
+	return string(contents), nil
+}
+
 // audioIntervalDuration converts the packet duration requested at startup to
 // one of the Opus durations supported by Mumble.
 func audioIntervalDuration(milliseconds int) (time.Duration, error) {