Refactored AuthenticationChallenge.cs and AuthenticationResponse.cs

websocket-sharp/AuthenticationChallenge.cs

@@ -29,6 +29,7 @@
 using System;
 using System.Collections.Specialized;
 using System.Text;
+using WebSocketSharp.Net;
 
 namespace WebSocketSharp
 {
@@ -36,17 +37,32 @@ namespace WebSocketSharp
   {
     #region Private Fields
 
-    private NameValueCollection _parameters;
+    private NameValueCollection   _parameters;
-    private string              _scheme;
+    private AuthenticationSchemes _scheme;
+
+    #endregion
+
+    #region Private Constructors
+
+    private AuthenticationChallenge (AuthenticationSchemes scheme, NameValueCollection parameters)
+    {
+      _scheme = scheme;
+      _parameters = parameters;
+    }
 
     #endregion
 
     #region Internal Constructors
 
-    internal AuthenticationChallenge (string scheme, string parameters)
+    internal AuthenticationChallenge (AuthenticationSchemes scheme, string realm)
+      : this (scheme, new NameValueCollection ())
     {
-      _scheme = scheme;
+      _parameters["realm"] = realm;
-      _parameters = parameters.ParseAuthParameters ();
+      if (scheme == AuthenticationSchemes.Digest) {
+        _parameters["nonce"] = AuthenticationResponse.CreateNonceValue ();
+        _parameters["algorithm"] = "MD5";
+        _parameters["qop"] = "auth";
+      }
     }
 
     #endregion
@@ -65,41 +81,41 @@ namespace WebSocketSharp
 
     public string Algorithm {
       get {
-        return _parameters ["algorithm"];
+        return _parameters["algorithm"];
       }
     }
 
     public string Domain {
       get {
-        return _parameters ["domain"];
+        return _parameters["domain"];
       }
     }
 
     public string Nonce {
       get {
-        return _parameters ["nonce"];
+        return _parameters["nonce"];
       }
     }
 
     public string Opaque {
       get {
-        return _parameters ["opaque"];
+        return _parameters["opaque"];
       }
     }
 
     public string Qop {
       get {
-        return _parameters ["qop"];
+        return _parameters["qop"];
       }
     }
 
     public string Realm {
       get {
-        return _parameters ["realm"];
+        return _parameters["realm"];
       }
     }
 
-    public string Scheme {
+    public AuthenticationSchemes Scheme {
       get {
         return _scheme;
       }
@@ -107,24 +123,66 @@ namespace WebSocketSharp
 
     public string Stale {
       get {
-        return _parameters ["stale"];
+        return _parameters["stale"];
       }
     }
 
     #endregion
 
+    #region Internal Methods
+
+    internal static AuthenticationChallenge CreateBasicChallenge (string realm)
+    {
+      return new AuthenticationChallenge (AuthenticationSchemes.Basic, realm);
+    }
+
+    internal static AuthenticationChallenge CreateDigestChallenge (string realm)
+    {
+      return new AuthenticationChallenge (AuthenticationSchemes.Digest, realm);
+    }
+
+    internal static AuthenticationChallenge Parse (string value)
+    {
+      var chal = value.Split (new[] { ' ' }, 2);
+      if (chal.Length != 2)
+        return null;
+
+      var scheme = chal[0].ToLower ();
+      return scheme == "basic"
+             ? new AuthenticationChallenge (
+                 AuthenticationSchemes.Basic, AuthenticationResponse.ParseParameters (chal[1]))
+             : scheme == "digest"
+               ? new AuthenticationChallenge (
+                   AuthenticationSchemes.Digest, AuthenticationResponse.ParseParameters (chal[1]))
+               : null;
+    }
+
+    internal string ToBasicString ()
+    {
+      return String.Format ("Basic realm=\"{0}\"", _parameters["realm"]);
+    }
+
+    internal string ToDigestString ()
+    {
+      return String.Format (
+        "Digest realm=\"{0}\", nonce=\"{1}\", algorithm={2}, qop=\"{3}\"",
+        _parameters["realm"],
+        _parameters["nonce"],
+        _parameters["algorithm"],
+        _parameters["qop"]);
+    }
+
+    #endregion
+
     #region Public Methods
 
-    public static AuthenticationChallenge Parse (string value)
+    public override string ToString ()
     {
-      var challenge = value.Split (new [] { ' ' }, 2);
+      return _scheme == AuthenticationSchemes.Basic
-      if (challenge.Length != 2)
+             ? ToBasicString ()
-        return null;
+             : _scheme == AuthenticationSchemes.Digest
-
+               ? ToDigestString ()
-      var scheme = challenge [0].ToLower ();
+               : String.Empty;
-      return scheme == "basic" || scheme == "digest"
-             ? new AuthenticationChallenge (scheme, challenge [1])
-             : null;
     }
 
     #endregion

websocket-sharp/AuthenticationResponse.cs

@@ -2,8 +2,12 @@
 /*
  * AuthenticationResponse.cs
  *
+ * ParseBasicCredentials is derived from System.Net.HttpListenerContext.cs of Mono
+ * (http://www.mono-project.com).
+ *
  * The MIT License
  *
+ * Copyright (c) 2005 Novell, Inc. (http://www.novell.com)
  * Copyright (c) 2013-2014 sta.blockhead
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
@@ -28,6 +32,7 @@
 
 using System;
 using System.Collections.Specialized;
+using System.Security.Cryptography;
 using System.Security.Principal;
 using System.Text;
 using WebSocketSharp.Net;
@@ -38,15 +43,15 @@ namespace WebSocketSharp
   {
     #region Private Fields
 
-    private uint                _nonceCount;
+    private uint                  _nonceCount;
-    private NameValueCollection _parameters;
+    private NameValueCollection   _parameters;
-    private string              _scheme;
+    private AuthenticationSchemes _scheme;
 
     #endregion
 
     #region Private Constructors
 
-    private AuthenticationResponse (string scheme, NameValueCollection parameters)
+    private AuthenticationResponse (AuthenticationSchemes scheme, NameValueCollection parameters)
     {
       _scheme = scheme;
       _parameters = parameters;
@@ -57,7 +62,7 @@ namespace WebSocketSharp
     #region Internal Constructors
 
     internal AuthenticationResponse (NetworkCredential credentials)
-      : this ("Basic", new NameValueCollection (), credentials, 0)
+      : this (AuthenticationSchemes.Basic, new NameValueCollection (), credentials, 0)
     {
     }
 
@@ -68,15 +73,17 @@ namespace WebSocketSharp
     }
 
     internal AuthenticationResponse (
-      string scheme, NameValueCollection parameters, NetworkCredential credentials, uint nonceCount)
+      AuthenticationSchemes scheme,
+      NameValueCollection parameters,
+      NetworkCredential credentials,
+      uint nonceCount)
+      : this (scheme, parameters)
     {
-      _scheme = scheme.ToLower ();
+      _parameters["username"] = credentials.UserName;
-      _parameters = parameters;
+      _parameters["password"] = credentials.Password;
-      _parameters ["username"] = credentials.UserName;
+      _parameters["uri"] = credentials.Domain;
-      _parameters ["password"] = credentials.Password;
-      _parameters ["uri"] = credentials.Domain;
       _nonceCount = nonceCount;
-      if (_scheme == "digest")
+      if (scheme == AuthenticationSchemes.Digest)
         initAsDigest ();
     }
 
@@ -104,59 +111,59 @@ namespace WebSocketSharp
 
     public string Algorithm {
       get {
-        return _parameters ["algorithm"];
+        return _parameters["algorithm"];
       }
     }
 
     public string Cnonce {
       get {
-        return _parameters ["cnonce"];
+        return _parameters["cnonce"];
       }
     }
 
     public string Nc {
       get {
-        return _parameters ["nc"];
+        return _parameters["nc"];
       }
     }
 
     public string Nonce {
       get {
-        return _parameters ["nonce"];
+        return _parameters["nonce"];
       }
     }
 
     public string Opaque {
       get {
-        return _parameters ["opaque"];
+        return _parameters["opaque"];
       }
     }
 
     public string Password {
       get {
-        return _parameters ["password"];
+        return _parameters["password"];
       }
     }
 
     public string Qop {
       get {
-        return _parameters ["qop"];
+        return _parameters["qop"];
       }
     }
 
     public string Realm {
       get {
-        return _parameters ["realm"];
+        return _parameters["realm"];
       }
     }
 
     public string Response {
       get {
-        return _parameters ["response"];
+        return _parameters["response"];
       }
     }
 
-    public string Scheme {
+    public AuthenticationSchemes Scheme {
       get {
         return _scheme;
       }
@@ -164,13 +171,13 @@ namespace WebSocketSharp
 
     public string Uri {
       get {
-        return _parameters ["uri"];
+        return _parameters["uri"];
       }
     }
 
     public string UserName {
       get {
-        return _parameters ["username"];
+        return _parameters["username"];
       }
     }
 
@@ -178,40 +185,119 @@ namespace WebSocketSharp
 
     #region Private Methods
 
+    private static string createA1 (string username, string password, string realm)
+    {
+      return String.Format ("{0}:{1}:{2}", username, realm, password);
+    }
+
+    private static string createA1 (
+      string username, string password, string realm, string nonce, string cnonce)
+    {
+      return String.Format (
+        "{0}:{1}:{2}", hash (createA1 (username, password, realm)), nonce, cnonce);
+    }
+
+    private static string createA2 (string method, string uri)
+    {
+      return String.Format ("{0}:{1}", method, uri);
+    }
+
+    private static string createA2 (string method, string uri, string entity)
+    {
+      return String.Format ("{0}:{1}:{2}", method, uri, entity);
+    }
+
+    private static string hash (string value)
+    {
+      var src = Encoding.UTF8.GetBytes (value);
+      var md5 = MD5.Create ();
+      var hashed = md5.ComputeHash (src);
+
+      var res = new StringBuilder (64);
+      foreach (var b in hashed)
+        res.Append (b.ToString ("x2"));
+
+      return res.ToString ();
+    }
+
     private void initAsDigest ()
     {
-      var qops = _parameters ["qop"];
+      var qops = _parameters["qop"];
       if (qops != null) {
         if (qops.Split (',').Contains (qop => qop.Trim ().ToLower () == "auth")) {
-          _parameters ["qop"] = "auth";
+          _parameters["qop"] = "auth";
-          _parameters ["nc"] = String.Format ("{0:x8}", ++_nonceCount);
+          _parameters["nc"] = String.Format ("{0:x8}", ++_nonceCount);
-          _parameters ["cnonce"] = HttpUtility.CreateNonceValue ();
+          _parameters["cnonce"] = CreateNonceValue ();
         }
         else {
-          _parameters ["qop"] = null;
+          _parameters["qop"] = null;
         }
       }
 
-      _parameters ["method"] = "GET";
+      _parameters["method"] = "GET";
-      _parameters ["response"] = HttpUtility.CreateRequestDigest (_parameters);
+      _parameters["response"] = CreateRequestDigest (_parameters);
     }
 
     #endregion
 
-    #region Public Methods
+    #region Internal Methods
 
-    public static AuthenticationResponse Parse (string value)
+    internal static string CreateNonceValue ()
+    {
+      var src = new byte[16];
+      var rand = new Random ();
+      rand.NextBytes (src);
+
+      var res = new StringBuilder (32);
+      foreach (var b in src)
+        res.Append (b.ToString ("x2"));
+
+      return res.ToString ();
+    }
+
+    internal static string CreateRequestDigest (NameValueCollection parameters)
+    {
+      var username = parameters["username"];
+      var password = parameters["password"];
+      var realm = parameters["realm"];
+      var nonce = parameters["nonce"];
+      var uri = parameters["uri"];
+      var algorithm = parameters["algorithm"];
+      var qop = parameters["qop"];
+      var nc = parameters["nc"];
+      var cnonce = parameters["cnonce"];
+      var method = parameters["method"];
+
+      var a1 = algorithm != null && algorithm.ToLower () == "md5-sess"
+               ? createA1 (username, password, realm, nonce, cnonce)
+               : createA1 (username, password, realm);
+
+      var a2 = qop != null && qop.ToLower () == "auth-int"
+               ? createA2 (method, uri, parameters["entity"])
+               : createA2 (method, uri);
+
+      var secret = hash (a1);
+      var data = qop != null
+                 ? String.Format ("{0}:{1}:{2}:{3}:{4}", nonce, nc, cnonce, qop, hash (a2))
+                 : String.Format ("{0}:{1}", nonce, hash (a2));
+
+      return hash (String.Format ("{0}:{1}", secret, data));
+    }
+
+    internal static AuthenticationResponse Parse (string value)
     {
       try {
-        var credentials = value.Split (new [] { ' ' }, 2);
+        var cred = value.Split (new[] { ' ' }, 2);
-        if (credentials.Length != 2)
+        if (cred.Length != 2)
           return null;
 
-        var scheme = credentials [0].ToLower ();
+        var scheme = cred[0].ToLower ();
         return scheme == "basic"
-               ? new AuthenticationResponse (scheme, credentials [1].ParseBasicCredentials ())
+               ? new AuthenticationResponse (
+                   AuthenticationSchemes.Basic, ParseBasicCredentials (cred[1]))
                : scheme == "digest"
-                 ? new AuthenticationResponse (scheme, credentials [1].ParseAuthParameters ())
+                 ? new AuthenticationResponse (
+                     AuthenticationSchemes.Digest, ParseParameters (cred[1]))
                  : null;
       }
       catch {
@@ -220,23 +306,101 @@ namespace WebSocketSharp
       return null;
     }
 
+    internal static NameValueCollection ParseBasicCredentials (string value)
+    {
+      // Decode the basic-credentials (a Base64 encoded string).
+      var userPass = Encoding.Default.GetString (Convert.FromBase64String (value));
+
+      // The format is [<domain>\]<username>:<password>.
+      var i = userPass.IndexOf (':');
+      var user = userPass.Substring (0, i);
+      var pass = i < userPass.Length - 1 ? userPass.Substring (i + 1) : String.Empty;
+
+      // Check if 'domain' exists.
+      i = user.IndexOf ('\\');
+      if (i > -1)
+        user = user.Substring (i + 1);
+
+      var res = new NameValueCollection ();
+      res["username"] = user;
+      res["password"] = pass;
+
+      return res;
+    }
+
+    internal static NameValueCollection ParseParameters (string value)
+    {
+      var res = new NameValueCollection ();
+      foreach (var param in value.SplitHeaderValue (',')) {
+        var i = param.IndexOf ('=');
+        var name = i > 0 ? param.Substring (0, i).Trim () : null;
+        var val = i < 0
+                  ? param.Trim ().Trim ('"')
+                  : i < param.Length - 1
+                    ? param.Substring (i + 1).Trim ().Trim ('"')
+                    : String.Empty;
+
+        res.Add (name, val);
+      }
+
+      return res;
+    }
+
+    internal string ToBasicString ()
+    {
+      var userPass = String.Format ("{0}:{1}", _parameters["username"], _parameters["password"]);
+      var cred = Convert.ToBase64String (Encoding.UTF8.GetBytes (userPass));
+
+      return "Basic " + cred;
+    }
+
+    internal string ToDigestString ()
+    {
+      var res = new StringBuilder (64);
+      res.AppendFormat ("username=\"{0}\"", _parameters["username"]);
+      res.AppendFormat (", realm=\"{0}\"", _parameters["realm"]);
+      res.AppendFormat (", nonce=\"{0}\"", _parameters["nonce"]);
+      res.AppendFormat (", uri=\"{0}\"", _parameters["uri"]);
+
+      var algorithm = _parameters["algorithm"];
+      if (algorithm != null)
+        res.AppendFormat (", algorithm={0}", algorithm);
+
+      res.AppendFormat (", response=\"{0}\"", _parameters["response"]);
+
+      var qop = _parameters["qop"];
+      if (qop != null) {
+        res.AppendFormat (", qop={0}", qop);
+        res.AppendFormat (", nc={0}", _parameters["nc"]);
+        res.AppendFormat (", cnonce=\"{0}\"", _parameters["cnonce"]);
+      }
+
+      var opaque = _parameters["opaque"];
+      if (opaque != null)
+        res.AppendFormat (", opaque=\"{0}\"", opaque);
+
+      return "Digest " + res.ToString ();
+    }
+
+    #endregion
+
+    #region Public Methods
+
     public IIdentity ToIdentity ()
     {
-      return _scheme == "basic"
+      return _scheme == AuthenticationSchemes.Basic
-             ? new HttpBasicIdentity (
+             ? new HttpBasicIdentity (_parameters["username"], _parameters["password"]) as IIdentity
-                 _parameters ["username"], _parameters ["password"]) as IIdentity
+             : _scheme == AuthenticationSchemes.Digest
-             : _scheme == "digest"
                ? new HttpDigestIdentity (_parameters)
                : null;
     }
 
     public override string ToString ()
     {
-      return _scheme == "basic"
+      return _scheme == AuthenticationSchemes.Basic
-             ? HttpUtility.CreateBasicAuthCredentials (
+             ? ToBasicString ()
-                 _parameters ["username"], _parameters ["password"])
+             : _scheme == AuthenticationSchemes.Digest
-             : _scheme == "digest"
+               ? ToDigestString ()
-               ? HttpUtility.CreateDigestAuthCredentials (_parameters)
                : String.Empty;
     }
 

websocket-sharp/Ext.cs

@@ -6,7 +6,6 @@
  * - GetStatusDescription is derived from System.Net.HttpListenerResponse.cs
  * - IsPredefinedScheme is derived from System.Uri.cs
  * - MaybeUri is derived from System.Uri.cs
- * - ParseBasicCredentials is derived from System.Net.HttpListenerContext.cs
  *
  * The MIT License
  *
@@ -571,46 +570,6 @@ namespace WebSocketSharp
       return true;
     }
 
-    internal static NameValueCollection ParseAuthParameters (this string value)
-    {
-      var res = new NameValueCollection ();
-      foreach (var param in value.SplitHeaderValue (',')) {
-        var i = param.IndexOf ('=');
-        var name = i > 0 ? param.Substring (0, i).Trim () : null;
-        var val = i < 0
-                  ? param.Trim ().Trim ('"')
-                  : i < param.Length - 1
-                    ? param.Substring (i + 1).Trim ().Trim ('"')
-                    : String.Empty;
-
-        res.Add (name, val);
-      }
-
-      return res;
-    }
-
-    internal static NameValueCollection ParseBasicCredentials (this string value)
-    {
-      // Decode the basic-credentials (a Base64 encoded string).
-      var cred = Encoding.Default.GetString (Convert.FromBase64String (value));
-
-      // The format is [<domain>\]<username>:<password>.
-      var i = cred.IndexOf (':');
-      var user = cred.Substring (0, i);
-      var pass = i < cred.Length - 1 ? cred.Substring (i + 1) : String.Empty;
-
-      // Check if 'domain' exists.
-      i = user.IndexOf ('\\');
-      if (i > -1)
-        user = user.Substring (i + 1);
-
-      var res = new NameValueCollection ();
-      res ["username"] = user;
-      res ["password"] = pass;
-
-      return res;
-    }
-
     internal static string Quote (this string value)
     {
       return value.IsToken ()

websocket-sharp/Net/HttpDigestIdentity.cs

@@ -175,7 +175,7 @@ namespace WebSocketSharp.Net
       parameters ["method"] = method;
       parameters ["entity"] = entity;
 
-      return _parameters ["response"] == HttpUtility.CreateRequestDigest (parameters);
+      return _parameters ["response"] == AuthenticationResponse.CreateRequestDigest (parameters);
     }
 
     #endregion

websocket-sharp/Net/HttpUtility.cs

@@ -47,7 +47,6 @@ using System.Collections.Specialized;
 using System.Globalization;
 using System.IO;
 using System.Text;
-using System.Security.Cryptography;
 
 namespace WebSocketSharp.Net
 {
@@ -78,27 +77,6 @@ namespace WebSocketSharp.Net
 
     #region Private Methods
 
-    private static string getA1 (string username, string password, string realm)
-    {
-      return String.Format ("{0}:{1}:{2}", username, realm, password);
-    }
-
-    private static string getA1 (
-      string username, string password, string realm, string nonce, string cnonce)
-    {
-      return String.Format ("{0}:{1}:{2}", hash (getA1 (username, password, realm)), nonce, cnonce);
-    }
-
-    private static string getA2 (string method, string uri)
-    {
-      return String.Format ("{0}:{1}", method, uri);
-    }
-
-    private static string getA2 (string method, string uri, string entity)
-    {
-      return String.Format ("{0}:{1}:{2}", method, uri, entity);
-    }
-
     private static int getChar (byte [] bytes, int offset, int length)
     {
       var value = 0;
@@ -150,19 +128,6 @@ namespace WebSocketSharp.Net
                  : -1;
     }
 
-    private static string hash (string value)
-    {
-      var src = Encoding.UTF8.GetBytes (value);
-      var md5 = MD5.Create ();
-      var hashed = md5.ComputeHash (src);
-
-      var res = new StringBuilder (64);
-      foreach (var b in hashed)
-        res.Append (b.ToString ("x2"));
-
-      return res.ToString ();
-    }
-
     private static void initEntities ()
     {
       // Build the dictionary of HTML entity references.
@@ -532,103 +497,6 @@ namespace WebSocketSharp.Net
 
     #region Internal Methods
 
-    internal static string CreateBasicAuthChallenge (string realm)
-    {
-      return String.Format ("Basic realm=\"{0}\"", realm);
-    }
-
-    internal static string CreateBasicAuthCredentials (string username, string password)
-    {
-      var userPass = String.Format ("{0}:{1}", username, password);
-      var base64UserPass = Convert.ToBase64String (Encoding.UTF8.GetBytes (userPass));
-
-      return "Basic " + base64UserPass;
-    }
-
-    internal static string CreateDigestAuthChallenge (string realm)
-    {
-      var nonce = CreateNonceValue ();
-      var algorithm = "MD5";
-      var qop = "auth";
-
-      return String.Format (
-        "Digest realm=\"{0}\", nonce=\"{1}\", algorithm={2}, qop=\"{3}\"",
-        realm,
-        nonce,
-        algorithm,
-        qop);
-    }
-
-    internal static string CreateDigestAuthCredentials (NameValueCollection authParams)
-    {
-      var digestRes = new StringBuilder (64);
-      digestRes.AppendFormat ("username=\"{0}\"", authParams ["username"]);
-      digestRes.AppendFormat (", realm=\"{0}\"", authParams ["realm"]);
-      digestRes.AppendFormat (", nonce=\"{0}\"", authParams ["nonce"]);
-      digestRes.AppendFormat (", uri=\"{0}\"", authParams ["uri"]);
-
-      var algorithm = authParams ["algorithm"];
-      if (algorithm != null)
-        digestRes.AppendFormat (", algorithm={0}", algorithm);
-
-      digestRes.AppendFormat (", response=\"{0}\"", authParams ["response"]);
-
-      var qop = authParams ["qop"];
-      if (qop != null) {
-        digestRes.AppendFormat (", qop={0}", qop);
-        digestRes.AppendFormat (", nc={0}", authParams ["nc"]);
-        digestRes.AppendFormat (", cnonce=\"{0}\"", authParams ["cnonce"]);
-      }
-
-      var opaque = authParams ["opaque"];
-      if (opaque != null)
-        digestRes.AppendFormat (", opaque=\"{0}\"", opaque);
-
-      return "Digest " + digestRes.ToString ();
-    }
-
-    internal static string CreateNonceValue ()
-    {
-      var src = new byte [16];
-      var rand = new Random ();
-      rand.NextBytes (src);
-
-      var nonce = new StringBuilder (32);
-      foreach (var b in src)
-        nonce.Append (b.ToString ("x2"));
-
-      return nonce.ToString ();
-    }
-
-    internal static string CreateRequestDigest (NameValueCollection parameters)
-    {
-      var username = parameters ["username"];
-      var password = parameters ["password"];
-      var realm = parameters ["realm"];
-      var nonce = parameters ["nonce"];
-      var uri = parameters ["uri"];
-      var algorithm = parameters ["algorithm"];
-      var qop = parameters ["qop"];
-      var nc = parameters ["nc"];
-      var cnonce = parameters ["cnonce"];
-      var method = parameters ["method"];
-
-      var a1 = algorithm != null && algorithm.ToLower () == "md5-sess"
-               ? getA1 (username, password, realm, nonce, cnonce)
-               : getA1 (username, password, realm);
-
-      var a2 = qop != null && qop.ToLower () == "auth-int"
-               ? getA2 (method, uri, parameters ["entity"])
-               : getA2 (method, uri);
-
-      var secret = hash (a1);
-      var data = qop != null
-                 ? String.Format ("{0}:{1}:{2}:{3}:{4}", nonce, nc, cnonce, qop, hash (a2))
-                 : String.Format ("{0}:{1}", nonce, hash (a2));
-
-      return hash (String.Format ("{0}:{1}", secret, data));
-    }
-
     internal static Uri CreateRequestUrl (
       string requestUri, string host, bool websocketRequest, bool secure)
     {

websocket-sharp/Net/ListenerAsyncResult.cs

@@ -157,7 +157,7 @@ namespace WebSocketSharp.Net
       if (scheme == AuthenticationSchemes.Basic &&
           (header == null || !header.StartsWith ("basic", StringComparison.OrdinalIgnoreCase))) {
         context.Response.CloseWithAuthChallenge (
-          HttpUtility.CreateBasicAuthChallenge (listener.Realm));
+          AuthenticationChallenge.CreateBasicChallenge (listener.Realm).ToBasicString ());
 
         listener.BeginGetContext (this);
         return;
@@ -166,7 +166,7 @@ namespace WebSocketSharp.Net
       if (scheme == AuthenticationSchemes.Digest &&
           (header == null || !header.StartsWith ("digest", StringComparison.OrdinalIgnoreCase))) {
         context.Response.CloseWithAuthChallenge (
-          HttpUtility.CreateDigestAuthChallenge (listener.Realm));
+          AuthenticationChallenge.CreateDigestChallenge (listener.Realm).ToDigestString ());
 
         listener.BeginGetContext (this);
         return;

websocket-sharp/Server/HttpServer.cs

@@ -521,10 +521,10 @@ namespace WebSocketSharp.Server
 
       if (scheme == AuthenticationSchemes.Basic)
         context.Response.CloseWithAuthChallenge (
-          HttpUtility.CreateBasicAuthChallenge (_listener.Realm));
+          AuthenticationChallenge.CreateBasicChallenge (_listener.Realm).ToBasicString ());
       else if (scheme == AuthenticationSchemes.Digest)
         context.Response.CloseWithAuthChallenge (
-          HttpUtility.CreateDigestAuthChallenge (_listener.Realm));
+          AuthenticationChallenge.CreateDigestChallenge (_listener.Realm).ToDigestString ());
       else
         context.Response.Close (HttpStatusCode.Forbidden);
 

websocket-sharp/Server/WebSocketServer.cs

@@ -522,10 +522,10 @@ namespace WebSocketSharp.Server
       AuthenticationSchemes scheme, TcpListenerWebSocketContext context)
     {
       var challenge = scheme == AuthenticationSchemes.Basic
-                    ? HttpUtility.CreateBasicAuthChallenge (Realm)
+                      ? AuthenticationChallenge.CreateBasicChallenge (Realm).ToBasicString ()
-                    : scheme == AuthenticationSchemes.Digest
+                      : scheme == AuthenticationSchemes.Digest
-                      ? HttpUtility.CreateDigestAuthChallenge (Realm)
+                        ? AuthenticationChallenge.CreateDigestChallenge (Realm).ToDigestString ()
-                      : null;
+                        : null;
 
       if (challenge == null) {
         context.Close (HttpStatusCode.Forbidden);

websocket-sharp/WebSocket.cs

@@ -1236,7 +1236,8 @@ namespace WebSocketSharp
       var res = sendHandshakeRequest (req);
       if (res.IsUnauthorized) {
         _authChallenge = res.AuthChallenge;
-        if (_credentials != null && (!_preAuth || _authChallenge.Scheme == "digest")) {
+        if (_credentials != null &&
+            (!_preAuth || _authChallenge.Scheme == AuthenticationSchemes.Digest)) {
           if (res.Headers.Contains ("Connection", "close")) {
             closeClientResources ();
             setClientStream ();