feat: rework relay validation

cmd/portal/main.go

@@ -1,14 +1,11 @@
 package main
 
 import (
-	"errors"
 	"fmt"
 	"io"
 	"log"
-	"net"
 	"os"
 	"path/filepath"
-	"unicode/utf8"
 
 	tea "github.com/charmbracelet/bubbletea"
 	homedir "github.com/mitchellh/go-homedir"
@@ -106,17 +103,6 @@ func initViperConfig() {
 	}
 }
 
-// validateRendezvousAddressInViper validates that the `rendezvousAddress` value in viper is a valid hostname or IP
-func validateRendezvousAddressInViper() error {
-	rendezvouzAdress := net.ParseIP(viper.GetString("rendezvousAddress"))
-	err := validateHostname(viper.GetString("rendezvousAddress"))
-	// neither a valid IP nor a valid hostname was provided
-	if (rendezvouzAdress == nil) && err != nil {
-		return errors.New("invalid IP or hostname provided")
-	}
-	return nil
-}
-
 func setupLoggingFromViper(cmd string) (*os.File, error) {
 	if viper.GetBool("verbose") {
 		f, err := tea.LogToFile(fmt.Sprintf(".portal-%s.log", cmd), fmt.Sprintf("portal-%s: \n", cmd))
@@ -128,58 +114,3 @@ func setupLoggingFromViper(cmd string) (*os.File, error) {
 	log.SetOutput(io.Discard)
 	return nil, nil
 }
-
-// validateHostname returns an error if the domain name is not valid
-// See https://tools.ietf.org/html/rfc1034#section-3.5 and
-// https://tools.ietf.org/html/rfc1123#section-2.
-// source: https://gist.github.com/chmike/d4126a3247a6d9a70922fc0e8b4f4013
-func validateHostname(name string) error {
-	switch {
-	case len(name) == 0:
-		return nil
-	case len(name) > 255:
-		return fmt.Errorf("name length is %d, can't exceed 255", len(name))
-	}
-	var l int
-	for i := 0; i < len(name); i++ {
-		b := name[i]
-		if b == '.' {
-			// check domain labels validity
-			switch {
-			case i == l:
-				return fmt.Errorf("invalid character '%c' at offset %d: label can't begin with a period", b, i)
-			case i-l > 63:
-				return fmt.Errorf("byte length of label '%s' is %d, can't exceed 63", name[l:i], i-l)
-			case name[l] == '-':
-				return fmt.Errorf("label '%s' at offset %d begins with a hyphen", name[l:i], l)
-			case name[i-1] == '-':
-				return fmt.Errorf("label '%s' at offset %d ends with a hyphen", name[l:i], l)
-			}
-			l = i + 1
-			continue
-		}
-		// test label character validity, note: tests are ordered by decreasing validity frequency
-		if !(b >= 'a' && b <= 'z' || b >= '0' && b <= '9' || b == '-' || b >= 'A' && b <= 'Z') {
-			// show the printable unicode character starting at byte offset i
-			c, _ := utf8.DecodeRuneInString(name[i:])
-			if c == utf8.RuneError {
-				return fmt.Errorf("invalid rune at offset %d", i)
-			}
-			return fmt.Errorf("invalid character '%c' at offset %d", c, i)
-		}
-	}
-	// check top level domain validity
-	switch {
-	case l == len(name):
-		return fmt.Errorf("missing top level domain, domain can't end with a period")
-	case len(name)-l > 63:
-		return fmt.Errorf("byte length of top level domain '%s' is %d, can't exceed 63", name[l:], len(name)-l)
-	case name[l] == '-':
-		return fmt.Errorf("top level domain '%s' at offset %d begins with a hyphen", name[l:], l)
-	case name[len(name)-1] == '-':
-		return fmt.Errorf("top level domain '%s' at offset %d ends with a hyphen", name[l:], l)
-	case name[l] >= '0' && name[l] <= '9':
-		return fmt.Errorf("top level domain '%s' at offset %d begins with a digit", name[l:], l)
-	}
-	return nil
-}

cmd/portal/receive.go

@@ -32,16 +32,15 @@ var receiveCmd = &cobra.Command{
 	Args:              cobra.ExactArgs(1),
 	ValidArgsFunction: passwordCompletion,
 	PreRunE: func(cmd *cobra.Command, args []string) error {
-		// Bind flags to viper
+		// BindvalidateRelayInViper
 		if err := viper.BindPFlag("relay", cmd.Flags().Lookup("relay")); err != nil {
 			return fmt.Errorf("binding relay flag: %w", err)
 		}
 		return nil
 	},
 	RunE: func(cmd *cobra.Command, args []string) error {
 		file.RemoveTemporaryFiles(file.RECEIVE_TEMP_FILE_NAME_PREFIX)
-		err := validateRendezvousAddressInViper()
-		if err != nil {
+		if err := validateRelayInViper(); err != nil {
 			return err
 		}
 		logFile, err := setupLoggingFromViper("receive")

cmd/portal/send.go

@@ -15,7 +15,7 @@ import (
 // Set flags.
 func init() {
 	// Add subcommand flags (dummy default values as default values are handled through viper)
-	sendCmd.Flags().StringP("relay", "r", "", "address of the relay server")
+	sendCmd.Flags().StringP("relay", "r", "", "Address of the relay server ()")
 }
 
 // ------------------------------------------------------ Command ------------------------------------------------------
@@ -39,7 +39,8 @@ var sendCmd = &cobra.Command{
 			return err
 		}
 		file.RemoveTemporaryFiles(file.SEND_TEMP_FILE_NAME_PREFIX)
-		if err := validateRendezvousAddressInViper(); err != nil {
+
+		if err := validateRelayInViper(); err != nil {
 			return err
 		}
 

cmd/portal/validate.go

@@ -0,0 +1,43 @@
+package main
+
+import (
+	"errors"
+	"net"
+	"regexp"
+	"strings"
+
+	"github.com/spf13/viper"
+	"golang.org/x/net/idna"
+)
+
+var ErrInvalidRelay = errors.New("invalid relay provided")
+
+var ipv6Rex = regexp.MustCompile(`\[(.*?)\]`)
+
+func stripPort(addr string) string {
+	split := strings.Split(addr, ":")
+	if len(split) == 2 {
+		return split[0]
+	}
+
+	matches := ipv6Rex.FindStringSubmatch(addr)
+	if len(matches) >= 2 {
+		return matches[1]
+	}
+	return addr
+}
+
+// validateRelayInViper validates that the `rendezvousAddress` value in viper is a valid hostname or IP
+func validateRelayInViper() error {
+	relayAddr := viper.GetString("relay")
+
+	if ip := net.ParseIP(stripPort(relayAddr)); ip != nil {
+		return nil
+	}
+
+	if _, err := idna.Lookup.ToASCII(relayAddr); err == nil {
+		return nil
+	}
+
+	return ErrInvalidRelay
+}