From f586cfe515a6e21e58f58a8a9aef38a07b979778 Mon Sep 17 00:00:00 2001
From: Uncled1023 <admin@teknik.io>
Date: Wed, 18 May 2016 16:52:32 -0700
Subject: [PATCH] Added filter for usernames.

---
 .../Views/Transparency/Index.cshtml             |  3 +++
 Teknik/Areas/User/Utility/UserHelper.cs         | 17 +++++++++++++++--
 Teknik/Configuration/UserConfig.cs              |  6 ++++++
 3 files changed, 24 insertions(+), 2 deletions(-)

diff --git a/Teknik/Areas/Transparency/Views/Transparency/Index.cshtml b/Teknik/Areas/Transparency/Views/Transparency/Index.cshtml
index 0fe0dde..fea5abf 100644
--- a/Teknik/Areas/Transparency/Views/Transparency/Index.cshtml
+++ b/Teknik/Areas/Transparency/Views/Transparency/Index.cshtml
@@ -259,7 +259,10 @@
         </div>
         <div class="row">
             <div class="col-sm-8 col-sm-offset-2">
+                @if (!string.IsNullOrEmpty(Model.Canary))
+                {
                 <pre>@Model.Canary</pre>
+                }
             </div>
         </div>
     }
diff --git a/Teknik/Areas/User/Utility/UserHelper.cs b/Teknik/Areas/User/Utility/UserHelper.cs
index ac23bee..bce7ae2 100644
--- a/Teknik/Areas/User/Utility/UserHelper.cs
+++ b/Teknik/Areas/User/Utility/UserHelper.cs
@@ -6,6 +6,7 @@ using System.Linq;
 using System.Net;
 using System.Runtime.InteropServices;
 using System.Text;
+using System.Text.RegularExpressions;
 using System.Threading.Tasks;
 using System.Web;
 using System.Web.Security;
@@ -64,10 +65,22 @@ namespace Teknik.Areas.Users.Utility
         {
             bool isValid = true;
 
+            // Must be something there
+            isValid &= !string.IsNullOrEmpty(username);
+
+            // Is the format correct?
+            Regex reg = new Regex(config.UserConfig.UsernameFilter);
+            isValid &= reg.IsMatch(username);
+
+            // Meets the min length?
+            isValid &= (username.Length >= config.UserConfig.MinUsernameLength);
+
+            // Meets the max length?
+            isValid &= (username.Length <= config.UserConfig.MaxUsernameLength);
+
             // Load reserved usernames
             List<string> reserved = GetReservedUsernames(config);
-            if (reserved.Exists(u => u.ToLower() == username.ToLower()))
-                isValid = false;
+            isValid &= (reserved.Exists(u => u.ToLower() == username.ToLower()));
 
             return isValid;
         }
diff --git a/Teknik/Configuration/UserConfig.cs b/Teknik/Configuration/UserConfig.cs
index 08d3472..0d8d7f4 100644
--- a/Teknik/Configuration/UserConfig.cs
+++ b/Teknik/Configuration/UserConfig.cs
@@ -10,12 +10,18 @@ namespace Teknik.Configuration
     {
         public bool RegistrationEnabled { get; set; }
         public bool LoginEnabled { get; set; }
+        public string UsernameFilter { get; set; }
+        public int MinUsernameLength { get; set; }
+        public int MaxUsernameLength { get; set; }
         public string ReservedUsernameDefinitionFile { get; set; }
 
         public UserConfig()
         {
             RegistrationEnabled = true;
             LoginEnabled = true;
+            UsernameFilter = "^[a-zA-Z0-9_-]+(?:\\.[a-zA-Z0-9_-]+)*$";
+            MinUsernameLength = 1;
+            MaxUsernameLength = 35;
             ReservedUsernameDefinitionFile = string.Empty;
         }
     }