refact

src/isnd/Controllers/SafeNameAttribute.cs

@@ -0,0 +1,20 @@
+using System;
+using System.ComponentModel.DataAnnotations;
+using System.Linq;
+
+namespace isn.Controllers
+{
+    internal class SafeNameAttribute : ValidationAttribute
+    {
+        public override bool IsValid(object value)
+        {
+            if (!(value is string))
+                return false;
+            string str = value as string;
+            if (str.Length>126) return false;
+            if (str.Any(c => !char.IsLetterOrDigit(c)
+            && !"-_.".Contains(c))) return false;
+            return true;
+        }
+    }
+}