fix(node): enhance public address validation for hostnames with stricter rules

Author: akrem-chabchoub

pkg/node/node.go

@@ -81,6 +81,7 @@ import (
 	ma "github.com/multiformats/go-multiaddr"
 	"github.com/prometheus/client_golang/prometheus"
 	"golang.org/x/crypto/sha3"
+	"golang.org/x/net/idna"
 	"golang.org/x/sync/errgroup"
 )
 
@@ -1498,5 +1499,15 @@ func validatePublicAddress(addr string) error {
 		return nil
 	}
 
+	idnaValidator := idna.New(
+		idna.ValidateLabels(true),
+		idna.VerifyDNSLength(true),
+		idna.StrictDomainName(true),
+		idna.CheckHyphens(true),
+	)
+	if _, err := idnaValidator.ToASCII(host); err != nil {
+		return fmt.Errorf("invalid hostname: %w", err)
+	}
+
 	return nil
 }

pkg/node/node_test.go

@@ -69,8 +69,13 @@ func TestValidatePublicAddress(t *testing.T) {
 			expErr: false,
 		},
 		{
-			name:   "hostname format valid",
-			addr:   "not-an-ip:8080",
+			name:   "valid hostname",
+			addr:   "example.com:8080",
+			expErr: false,
+		},
+		{
+			name:   "valid hostname with hyphen",
+			addr:   "test-example.com:8080",
 			expErr: false,
 		},
 		{
@@ -79,13 +84,13 @@ func TestValidatePublicAddress(t *testing.T) {
 			expErr: true,
 		},
 		{
-			name:   "hostname",
-			addr:   "example.com:8080",
-			expErr: false,
+			name:   "invalid hostname format",
+			addr:   "invalid..hostname:8080",
+			expErr: true,
 		},
 		{
-			name:   "hostname without port",
-			addr:   "example.com",
+			name:   "hostname starts with hyphen",
+			addr:   "-test.com:8080",
 			expErr: true,
 		},
 	}