Function LoadClient

internal/config/client.go:291–416

LoadClient reads and validates a client config file.

(path string)

// LoadClient reads and validates a client config file.
func LoadClient(path string) (*Client, error) {
	b, err := os.ReadFile(path)
	if err != nil {
		if errors.Is(err, fs.ErrNotExist) {
			return nil, fmt.Errorf("config file %q not found.\n  Fix: copy the example and edit it:\n      cp client_config.example.json %s", path, path)
		}
		return nil, fmt.Errorf("cannot read config %q: %w", path, err)
	}

	var f clientFile
	if err := json.Unmarshal(b, &f); err != nil {
		return nil, fmt.Errorf("config %q is not valid JSON: %v\n  Common causes: missing comma between fields, trailing comma after the last field, unclosed quote, or a typo in a field name", path, err)
	}

	listenHost := firstNonEmpty(f.SocksHost, "127.0.0.1")
	listenPort := firstPositive(f.SocksPort)
	if listenPort == 0 {
		listenPort = 1080
	}
	if listenPort < 1 || listenPort > 65535 {
		return nil, fmt.Errorf("socks_port %d is out of range (must be 1-65535)", listenPort)
	}

	relayURLs := make([]string, 0, len(f.RelayURLs))
	for _, raw := range f.RelayURLs {
		normalized, nerr := normalizeRelayURL(raw)
		if nerr != nil {
			return nil, nerr
		}
		if normalized != "" {
			relayURLs = append(relayURLs, normalized)
		}
	}
	relayURLs = dedupeStrings(relayURLs)

	key := strings.TrimSpace(f.TunnelKey)
	if key == "" || key == "REPLACE_WITH_64_HEX_CHARACTER_RANDOM_KEY" {
		return nil, fmt.Errorf("tunnel_key is empty or still the placeholder text in %s.\n  Fix: generate a key with 'openssl rand -hex 32' and paste the 64-character output into the tunnel_key field. The same value must be in server_config.json", path)
	}
	if len(key) != 64 {
		return nil, fmt.Errorf("tunnel_key must be exactly 64 hex characters (got %d) in %s.\n  Fix: generate a fresh key with 'openssl rand -hex 32' and paste the full output. Use the SAME value in client_config.json and server_config.json", len(key), path)
	}
	raw, err := hex.DecodeString(key)
	if err != nil || len(raw) != 32 {
		return nil, fmt.Errorf("tunnel_key in %s contains non-hex characters.\n  Valid characters are 0-9 and a-f. Generate a fresh key with 'openssl rand -hex 32' and copy it carefully — no spaces, quotes, or extra newlines", path)
	}

	useFronting := len(relayURLs) == 0
	scriptURLs := relayURLs
	scriptAccounts := make([]string, len(relayURLs)) // direct relay_urls have no account labels
	googleIP := ""
	var sniHosts []string

	if useFronting {
		googleHost := firstNonEmpty(f.GoogleHost, "216.239.38.120")
		googlePort := 443
		googleIP = net.JoinHostPort(googleHost, strconv.Itoa(googlePort))
		sniHosts = parseSNIHosts(f.SNI)