[System]: WebRequest.GetSystemProxy(): Return custom proxy for monodroid.
[mono.git] / mcs / class / System / System.Net / WebHeaderCollection.cs
index 790628771fb58524fc1e7328f6a9b4aae72c1509..a2516b0cc39bfa47a5629f32def08a9938fb1e01 100644 (file)
@@ -5,10 +5,11 @@
 //     Lawrence Pit (loz@cable.a2000.nl)
 //     Gonzalo Paniagua Javier (gonzalo@ximian.com)
 //      Miguel de Icaza (miguel@novell.com)
+//     Marek Safar (marek.safar@gmail.com)
 //
 // Copyright 2003 Ximian, Inc. (http://www.ximian.com)
 // Copyright 2007 Novell, Inc. (http://www.novell.com)
-//
+// Copyright (C) 2011 Xamarin Inc (http://www.xamarin.com)
 //
 //
 // Permission is hereby granted, free of charge, to any person obtaining
@@ -33,6 +34,7 @@
 
 using System;
 using System.Collections;
+using System.Collections.Generic;
 using System.Collections.Specialized;
 using System.Runtime.InteropServices;
 using System.Runtime.Serialization;
@@ -44,83 +46,103 @@ namespace System.Net
 {
        [Serializable]
        [ComVisible(true)]
-       public class WebHeaderCollection : NameValueCollection, ISerializable
-       {
-               private static readonly Hashtable restricted;
-               private static readonly Hashtable multiValue;
-               private bool internallyCreated = false;
-               
-               // Static Initializer
+       public class WebHeaderCollection : NameValueCollection, ISerializable {
+               [Flags]
+               internal enum HeaderInfo
+               {
+                       Request = 1,
+                       Response = 1 << 1,
+                       MultiValue = 1 << 10
+               }
+
+               static readonly bool[] allowed_chars = {
+                       false, false, false, false, false, false, false, false, false, false, false, false, false, false,
+                       false, false, false, false, false, false, false, false, false, false, false, false, false, false,
+                       false, false, false, false, false, true, false, true, true, true, true, false, false, false, true,
+                       true, false, true, true, false, true, true, true, true, true, true, true, true, true, true, false,
+                       false, false, false, false, false, false, true, true, true, true, true, true, true, true, true,
+                       true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true,
+                       false, false, false, true, true, true, true, true, true, true, true, true, true, true, true, true,
+                       true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true,
+                       false, true, false
+               };
+
+               static readonly Dictionary<string, HeaderInfo> headers;
+               HeaderInfo? headerRestriction;
+               HeaderInfo? headerConsistency;
                
                static WebHeaderCollection () 
                {
-                       // the list of restricted header names as defined 
-                       // by the ms.net spec
-                       restricted = new Hashtable (CaseInsensitiveHashCodeProvider.Default,
-                                                   CaseInsensitiveComparer.Default);
-
-                       restricted.Add ("accept", true);
-                       restricted.Add ("connection", true);
-                       restricted.Add ("content-length", true);
-                       restricted.Add ("content-type", true);
-                       restricted.Add ("date", true);
-                       restricted.Add ("expect", true);
-                       restricted.Add ("host", true);
-                       restricted.Add ("if-modified-since", true);
-                       restricted.Add ("range", true);
-                       restricted.Add ("referer", true);
-                       restricted.Add ("transfer-encoding", true);
-                       restricted.Add ("user-agent", true);                    
-                       
-                       // see par 14 of RFC 2068 to see which header names
-                       // accept multiple values each separated by a comma
-                       multiValue = new Hashtable (CaseInsensitiveHashCodeProvider.Default,
-                                                   CaseInsensitiveComparer.Default);
-
-                       multiValue.Add ("accept", true);
-                       multiValue.Add ("accept-charset", true);
-                       multiValue.Add ("accept-encoding", true);
-                       multiValue.Add ("accept-language", true);
-                       multiValue.Add ("accept-ranges", true);
-                       multiValue.Add ("allow", true);
-                       multiValue.Add ("authorization", true);
-                       multiValue.Add ("cache-control", true);
-                       multiValue.Add ("connection", true);
-                       multiValue.Add ("content-encoding", true);
-                       multiValue.Add ("content-language", true);                      
-                       multiValue.Add ("expect", true);                
-                       multiValue.Add ("if-match", true);
-                       multiValue.Add ("if-none-match", true);
-                       multiValue.Add ("proxy-authenticate", true);
-                       multiValue.Add ("public", true);                        
-                       multiValue.Add ("range", true);
-                       multiValue.Add ("transfer-encoding", true);
-                       multiValue.Add ("upgrade", true);
-                       multiValue.Add ("vary", true);
-                       multiValue.Add ("via", true);
-                       multiValue.Add ("warning", true);
-
-                       // Extra
-                       multiValue.Add ("set-cookie", true);
-                       multiValue.Add ("set-cookie2", true);
+                       headers = new Dictionary<string, HeaderInfo> (StringComparer.OrdinalIgnoreCase) {
+                               { "Allow", HeaderInfo.MultiValue },
+                               { "Accept", HeaderInfo.Request | HeaderInfo.MultiValue },
+                               { "Accept-Charset", HeaderInfo.MultiValue },
+                               { "Accept-Encoding", HeaderInfo.MultiValue },
+                               { "Accept-Language", HeaderInfo.MultiValue },
+                               { "Accept-Ranges", HeaderInfo.MultiValue },
+                               { "Authorization", HeaderInfo.MultiValue },
+                               { "Cache-Control", HeaderInfo.MultiValue },
+                               { "Cookie", HeaderInfo.MultiValue },
+                               { "Connection", HeaderInfo.Request | HeaderInfo.MultiValue },
+                               { "Content-Encoding", HeaderInfo.MultiValue },
+                               { "Content-Length", HeaderInfo.Request | HeaderInfo.Response },
+                               { "Content-Type", HeaderInfo.Request },
+                               { "Content-Language", HeaderInfo.MultiValue },
+                               { "Date", HeaderInfo.Request },
+                               { "Expect", HeaderInfo.Request | HeaderInfo.MultiValue},
+                               { "Host", HeaderInfo.Request },
+                               { "If-Match", HeaderInfo.MultiValue },
+                               { "If-Modified-Since", HeaderInfo.Request },
+                               { "If-None-Match", HeaderInfo.MultiValue },
+                               { "Keep-Alive", HeaderInfo.Response },
+                               { "Pragma", HeaderInfo.MultiValue },
+                               { "Proxy-Authenticate", HeaderInfo.MultiValue },
+                               { "Proxy-Authorization", HeaderInfo.MultiValue },
+                               { "Proxy-Connection", HeaderInfo.Request | HeaderInfo.MultiValue },
+                               { "Range", HeaderInfo.Request | HeaderInfo.MultiValue },
+                               { "Referer", HeaderInfo.Request },
+                               { "Set-Cookie", HeaderInfo.MultiValue },
+                               { "Set-Cookie2", HeaderInfo.MultiValue },
+                               { "TE", HeaderInfo.MultiValue },
+                               { "Trailer", HeaderInfo.MultiValue },
+                               { "Transfer-Encoding", HeaderInfo.Request | HeaderInfo.Response | HeaderInfo.MultiValue },
+                               { "Upgrade", HeaderInfo.MultiValue },
+                               { "User-Agent", HeaderInfo.Request },
+                               { "Vary", HeaderInfo.MultiValue },
+                               { "Via", HeaderInfo.MultiValue },
+                               { "Warning", HeaderInfo.MultiValue },
+                               { "WWW-Authenticate", HeaderInfo.Response | HeaderInfo. MultiValue }
+                       };
                }
                
                // Constructors
                
-               public WebHeaderCollection () { }       
+               public WebHeaderCollection ()
+               {
+               }
                
                protected WebHeaderCollection (SerializationInfo serializationInfo, 
                                               StreamingContext streamingContext)
                {
-                       int count = serializationInfo.GetInt32("Count");
-                       for (int i = 0; i < count; i++) 
-                               this.Add (serializationInfo.GetString (i.ToString ()),
-                                       serializationInfo.GetString ((count + i).ToString ()));
+                       int count;
+
+                       try {
+                               count = serializationInfo.GetInt32("Count");
+                               for (int i = 0; i < count; i++) 
+                                       this.Add (serializationInfo.GetString (i.ToString ()),
+                                                 serializationInfo.GetString ((count + i).ToString ()));
+                       } catch (SerializationException){
+                               count = serializationInfo.GetInt32("count");
+                               for (int i = 0; i < count; i++) 
+                                       this.Add (serializationInfo.GetString ("k" + i),
+                                                 serializationInfo.GetString ("v" + i));
+                       }
+                       
                }
-               
-               internal WebHeaderCollection (bool internallyCreated)
-               {       
-                       this.internallyCreated = internallyCreated;
+
+               internal WebHeaderCollection (HeaderInfo headerRestriction)
+               {
+                       this.headerRestriction = headerRestriction;
                }               
                
                // Methods
@@ -131,17 +153,17 @@ namespace System.Net
                                throw new ArgumentNullException ("header");
                        int pos = header.IndexOf (':');
                        if (pos == -1)
-                               throw new ArgumentException ("no colon found", "header");                               
-                       this.Add (header.Substring (0, pos), 
-                                 header.Substring (pos + 1));
+                               throw new ArgumentException ("no colon found", "header");
+
+                       this.Add (header.Substring (0, pos), header.Substring (pos + 1));
                }
                
                public override void Add (string name, string value)
                {
                        if (name == null)
                                throw new ArgumentNullException ("name");
-                       if (internallyCreated && IsRestricted (name))
-                               throw new ArgumentException ("This header must be modified with the appropiate property.");
+
+                       CheckRestrictedHeader (name);
                        this.AddWithoutValidate (name, value);
                }
 
@@ -155,10 +177,16 @@ namespace System.Net
                                headerValue = headerValue.Trim ();
                        if (!IsHeaderValue (headerValue))
                                throw new ArgumentException ("invalid header value: " + headerValue, "headerValue");
+                       
+                       AddValue (headerName, headerValue);
+               }
+                       
+               internal void AddValue (string headerName, string headerValue)
+               {
                        base.Add (headerName, headerValue);                     
                }
 
-               public override string [] GetValues (string header)
+               internal string [] GetValues_internal (string header, bool split)
                {
                        if (header == null)
                                throw new ArgumentNullException ("header");
@@ -167,62 +195,77 @@ namespace System.Net
                        if (values == null || values.Length == 0)
                                return null;
 
-                       /*
-                       if (IsMultiValue (header)) {
-                               values = GetMultipleValues (values);
+                       if (split && IsMultiValue (header)) {
+                               List<string> separated = null;
+                               foreach (var value in values) {
+                                       if (value.IndexOf (',') < 0)
+                                               continue;
+
+                                       if (separated == null) {
+                                               separated = new List<string> (values.Length + 1);
+                                               foreach (var v in values) {
+                                                       if (v == value)
+                                                               break;
+
+                                                       separated.Add (v);
+                                               }
+                                       }
+
+                                       var slices = value.Split (',');
+                                       var slices_length = slices.Length;
+                                       if (value[value.Length - 1] == ',')
+                                               --slices_length;
+
+                                       for (int i = 0; i < slices_length; ++i ) {
+                                               separated.Add (slices[i].Trim ());
+                                       }
+                               }
+
+                               if (separated != null)
+                                       return separated.ToArray ();
                        }
-                       */
 
                        return values;
                }
 
-               /* Now i wonder why this is here...
-               static string [] GetMultipleValues (string [] values)
+               public override string [] GetValues (string header)
                {
-                       ArrayList mvalues = new ArrayList (values.Length);
-                       StringBuilder sb = null;
-                       for (int i = 0; i < values.Length; ++i) {
-                               string val = values [i];
-                               if (val.IndexOf (',') == -1) {
-                                       mvalues.Add (val);
-                                       continue;
-                               }
+                       return GetValues_internal (header, true);
+               }
 
-                               if (sb == null)
-                                       sb = new StringBuilder ();
-
-                               bool quote = false;
-                               for (int k = 0; k < val.Length; k++) {
-                                       char c = val [k];
-                                       if (c == '"') {
-                                               quote = !quote;
-                                       } else if (!quote && c == ',') {
-                                               mvalues.Add (sb.ToString ().Trim ());
-                                               sb.Length = 0;
-                                               continue;
-                                       }
-                                       sb.Append (c);
-                               }
+               public override string[] GetValues (int index)
+               {
+                       string[] values = base.GetValues (index);
 
-                               if (sb.Length > 0) {
-                                       mvalues.Add (sb.ToString ().Trim ());
-                                       sb.Length = 0;
-                               }
+                       if (values == null || values.Length == 0) {
+                               return null;
                        }
-
-                       return (string []) mvalues.ToArray (typeof (string));
+                       
+                       return values;
                }
-               */
 
                public static bool IsRestricted (string headerName)
+               {
+                       return IsRestricted (headerName, false);
+               }
+
+               public static bool IsRestricted (string headerName, bool response)
                {
                        if (headerName == null)
                                throw new ArgumentNullException ("headerName");
 
-                       if (headerName == "") // MS throw nullexception here!
+                       if (headerName.Length == 0)
                                throw new ArgumentException ("empty string", "headerName");
 
-                       return restricted.ContainsKey (headerName);
+                       if (!IsHeaderName (headerName))
+                               throw new ArgumentException ("Invalid character in header");
+
+                       HeaderInfo info;
+                       if (!headers.TryGetValue (headerName, out info))
+                               return false;
+
+                       var flag = response ? HeaderInfo.Response : HeaderInfo.Request;
+                       return (info & flag) != 0;
                }
 
                public override void OnDeserialization (object sender)
@@ -233,8 +276,8 @@ namespace System.Net
                {
                        if (name == null)
                                throw new ArgumentNullException ("name");
-                       if (internallyCreated && IsRestricted (name))
-                               throw new ArgumentException ("restricted header");
+
+                       CheckRestrictedHeader (name);
                        base.Remove (name);
                }
 
@@ -242,8 +285,6 @@ namespace System.Net
                {
                        if (name == null)
                                throw new ArgumentNullException ("name");
-                       if (internallyCreated && IsRestricted (name))
-                               throw new ArgumentException ("restricted header");
                        if (!IsHeaderName (name))
                                throw new ArgumentException ("invalid header name");
                        if (value == null)
@@ -252,6 +293,8 @@ namespace System.Net
                                value = value.Trim ();
                        if (!IsHeaderValue (value))
                                throw new ArgumentException ("invalid header value");
+
+                       CheckRestrictedHeader (name);
                        base.Set (name, value);                 
                }
 
@@ -260,6 +303,30 @@ namespace System.Net
                        return Encoding.UTF8.GetBytes(ToString ());
                }
 
+               internal string ToStringMultiValue ()
+               {
+                       StringBuilder sb = new StringBuilder();
+
+                       int count = base.Count;
+                       for (int i = 0; i < count ; i++) {
+                               string key = GetKey (i);
+                               if (IsMultiValue (key)) {
+                                       foreach (string v in GetValues (i)) {
+                                               sb.Append (key)
+                                                 .Append (": ")
+                                                 .Append (v)
+                                                 .Append ("\r\n");
+                                       }
+                               } else {
+                                       sb.Append (key)
+                                         .Append (": ")
+                                         .Append (Get (i))
+                                         .Append ("\r\n");
+                               }
+                        }
+                       return sb.Append("\r\n").ToString();
+               }
+
                public override string ToString ()
                {
                        StringBuilder sb = new StringBuilder();
@@ -270,12 +337,17 @@ namespace System.Net
                                  .Append (": ")
                                  .Append (Get (i))
                                  .Append ("\r\n");
-                                 
+
                        return sb.Append("\r\n").ToString();
                }
-
+#if !TARGET_JVM
                void ISerializable.GetObjectData (SerializationInfo serializationInfo,
                                                  StreamingContext streamingContext)
+               {
+                       GetObjectData (serializationInfo, streamingContext);
+               }
+#endif
+               public override void GetObjectData (SerializationInfo serializationInfo, StreamingContext streamingContext)
                {
                        int count = base.Count;
                        serializationInfo.AddValue ("Count", count);
@@ -285,244 +357,341 @@ namespace System.Net
                        }
                }
 
-#if NET_2_0
+               public override string[] AllKeys {
+                       get {
+                               return base.AllKeys;
+                       }
+               }
+               
+               public override int Count {
+                       get {
+                               return base.Count;
+                       }
+               }
+
+               public override KeysCollection Keys {
+                       get {
+                               return base.Keys;
+                       }
+               }
+
+               public override string Get (int index)
+               {
+                       return base.Get (index);
+               }
+               
+               public override string Get (string name)
+               {
+                       return base.Get (name);
+               }
+               
+               public override string GetKey (int index)
+               {
+                       return base.GetKey (index);
+               }
+
+               public void Add (HttpRequestHeader header, string value)
+               {
+                       Add (RequestHeaderToString (header), value);
+               }
+
+               public void Remove (HttpRequestHeader header)
+               {
+                       Remove (RequestHeaderToString (header));
+               }
+
+               public void Set (HttpRequestHeader header, string value)
+               {
+                       Set (RequestHeaderToString (header), value);
+               }
+
+               public void Add (HttpResponseHeader header, string value)
+               {
+                       Add (ResponseHeaderToString (header), value);
+               }
+
+               public void Remove (HttpResponseHeader header)
+               {
+                       Remove (ResponseHeaderToString (header));
+               }
+
+               public void Set (HttpResponseHeader header, string value)
+               {
+                       Set (ResponseHeaderToString (header), value);
+               }
+
+               public string this [HttpRequestHeader header] {
+                       get {
+                               return Get (RequestHeaderToString (header));
+                       }
+                       
+                       set {
+                               Set (header, value);
+                       }
+               }
+
+               public string this [HttpResponseHeader header] {
+                       get {
+                               return Get (ResponseHeaderToString (header));
+                       }
+
+                       set {
+                               Set (header, value);
+                       }
+               }
+
+               public override void Clear ()
+               {
+                       base.Clear ();
+               }
+
+               public override IEnumerator GetEnumerator ()
+               {
+                       return base.GetEnumerator ();
+               }
+
+               // Internal Methods
+               
+               // With this we don't check for invalid characters in header. See bug #55994.
+               internal void SetInternal (string header)
+               {
+                       int pos = header.IndexOf (':');
+                       if (pos == -1)
+                               throw new ArgumentException ("no colon found", "header");                               
+
+                       SetInternal (header.Substring (0, pos), header.Substring (pos + 1));
+               }
+
+               internal void SetInternal (string name, string value)
+               {
+                       if (value == null)
+                               value = String.Empty;
+                       else
+                               value = value.Trim ();
+                       if (!IsHeaderValue (value))
+                               throw new ArgumentException ("invalid header value");
+
+                       if (IsMultiValue (name)) {
+                               base.Add (name, value);
+                       } else {
+                               base.Remove (name);
+                               base.Set (name, value); 
+                       }
+               }
+
+               internal void RemoveAndAdd (string name, string value)
+               {
+                       if (value == null)
+                               value = String.Empty;
+                       else
+                               value = value.Trim ();
+
+                       base.Remove (name);
+                       base.Set (name, value);
+               }
+
+               internal void RemoveInternal (string name)
+               {
+                       if (name == null)
+                               throw new ArgumentNullException ("name");
+                       base.Remove (name);
+               }               
+               
+               // Private Methods
+
                string RequestHeaderToString (HttpRequestHeader value)
                {
-                       switch (value){
+                       CheckHeaderConsistency (HeaderInfo.Request);
+
+                       switch (value) {
                        case HttpRequestHeader.CacheControl:
-                               return "cache-control";
+                               return "Cache-Control";
                        case HttpRequestHeader.Connection:
-                               return "connection";
+                               return "Connection";
                        case HttpRequestHeader.Date:
-                               return "date";
+                               return "Date";
                        case HttpRequestHeader.KeepAlive:
-                               return "keep-alive";
+                               return "Keep-Alive";
                        case HttpRequestHeader.Pragma:
-                               return "pragma";
+                               return "Pragma";
                        case HttpRequestHeader.Trailer:
-                               return "trailer";
+                               return "Trailer";
                        case HttpRequestHeader.TransferEncoding:
-                               return "transfer-encoding";
+                               return "Transfer-Encoding";
                        case HttpRequestHeader.Upgrade:
-                               return "upgrade";
+                               return "Upgrade";
                        case HttpRequestHeader.Via:
-                               return "via";
+                               return "Via";
                        case HttpRequestHeader.Warning:
-                               return "warning";
+                               return "Warning";
                        case HttpRequestHeader.Allow:
-                               return "allow";
+                               return "Allow";
                        case HttpRequestHeader.ContentLength:
-                               return "content-length";
+                               return "Content-Length";
                        case HttpRequestHeader.ContentType:
-                               return "content-type";
+                               return "Content-Type";
                        case HttpRequestHeader.ContentEncoding:
-                               return "content-encoding";
+                               return "Content-Encoding";
                        case HttpRequestHeader.ContentLanguage:
-                               return "content-language";
+                               return "Content-Language";
                        case HttpRequestHeader.ContentLocation:
-                               return "content-location";
+                               return "Content-Location";
                        case HttpRequestHeader.ContentMd5:
-                               return "content-md5";
+                               return "Content-MD5";
                        case HttpRequestHeader.ContentRange:
-                               return "content-range";
+                               return "Content-Range";
                        case HttpRequestHeader.Expires:
-                               return "expires";
+                               return "Expires";
                        case HttpRequestHeader.LastModified:
-                               return "last-modified";
+                               return "Last-Modified";
                        case HttpRequestHeader.Accept:
-                               return "accept";
+                               return "Accept";
                        case HttpRequestHeader.AcceptCharset:
-                               return "accept-charset";
+                               return "Accept-Charset";
                        case HttpRequestHeader.AcceptEncoding:
-                               return "accept-encoding";
+                               return "Accept-Encoding";
                        case HttpRequestHeader.AcceptLanguage:
                                return "accept-language";
                        case HttpRequestHeader.Authorization:
-                               return "authorization";
+                               return "Authorization";
                        case HttpRequestHeader.Cookie:
-                               return "cookie";
+                               return "Cookie";
                        case HttpRequestHeader.Expect:
-                               return "expect";
+                               return "Expect";
                        case HttpRequestHeader.From:
-                               return "from";
+                               return "From";
                        case HttpRequestHeader.Host:
-                               return "host";
+                               return "Host";
                        case HttpRequestHeader.IfMatch:
-                               return "if-match";
+                               return "If-Match";
                        case HttpRequestHeader.IfModifiedSince:
-                               return "if-modified-since";
+                               return "If-Modified-Since";
                        case HttpRequestHeader.IfNoneMatch:
-                               return "if-none-match";
+                               return "If-None-Match";
                        case HttpRequestHeader.IfRange:
-                               return "if-range";
+                               return "If-Range";
                        case HttpRequestHeader.IfUnmodifiedSince:
-                               return "if-unmodified-since";
+                               return "If-Unmodified-Since";
                        case HttpRequestHeader.MaxForwards:
-                               return "max-forwards";
+                               return "Max-Forwards";
                        case HttpRequestHeader.ProxyAuthorization:
-                               return "proxy-authorization";
+                               return "Proxy-Authorization";
                        case HttpRequestHeader.Referer:
-                               return "referer";
+                               return "Referer";
                        case HttpRequestHeader.Range:
-                               return "range";
+                               return "Range";
                        case HttpRequestHeader.Te:
-                               return "te";
+                               return "TE";
                        case HttpRequestHeader.Translate:
-                               return "translate";
+                               return "Translate";
                        case HttpRequestHeader.UserAgent:
-                               return "user-agent";
+                               return "User-Agent";
                        default:
                                throw new InvalidOperationException ();
                        }
                }
-               
-               public string this[HttpRequestHeader hrh]
-               {
-                       get {
-                               return Get (RequestHeaderToString (hrh));
-                       }
-                       
-                       set {
-                               Add (RequestHeaderToString (hrh), value);
-                       }
-               }
 
                string ResponseHeaderToString (HttpResponseHeader value)
                {
-                       switch (value){
+                       CheckHeaderConsistency (HeaderInfo.Response);
+
+                       switch (value) {
                        case HttpResponseHeader.CacheControl:
-                               return "cache-control";
+                               return "Cache-Control";
                        case HttpResponseHeader.Connection:
-                               return "connection";
+                               return "Connection";
                        case HttpResponseHeader.Date:
-                               return "date";
+                               return "Date";
                        case HttpResponseHeader.KeepAlive:
-                               return "keep-alive";
+                               return "Keep-Alive";
                        case HttpResponseHeader.Pragma:
-                               return "pragma";
+                               return "Pragma";
                        case HttpResponseHeader.Trailer:
-                               return "trailer";
+                               return "Trailer";
                        case HttpResponseHeader.TransferEncoding:
-                               return "transfer-encoding";
+                               return "Transfer-Encoding";
                        case HttpResponseHeader.Upgrade:
-                               return "upgrade";
+                               return "Upgrade";
                        case HttpResponseHeader.Via:
-                               return "via";
+                               return "Via";
                        case HttpResponseHeader.Warning:
-                               return "warning";
+                               return "Warning";
                        case HttpResponseHeader.Allow:
-                               return "allow";
+                               return "Allow";
                        case HttpResponseHeader.ContentLength:
-                               return "content-length";
+                               return "Content-Length";
                        case HttpResponseHeader.ContentType:
-                               return "content-type";
+                               return "Content-Type";
                        case HttpResponseHeader.ContentEncoding:
-                               return "content-encoding";
+                               return "Content-Encoding";
                        case HttpResponseHeader.ContentLanguage:
-                               return "content-language";
+                               return "Content-Language";
                        case HttpResponseHeader.ContentLocation:
-                               return "content-location";
+                               return "Content-Location";
                        case HttpResponseHeader.ContentMd5:
-                               return "content-md5";
+                               return "Content-MD5";
                        case HttpResponseHeader.ContentRange:
-                               return "content-range";
+                               return "Content-Range";
                        case HttpResponseHeader.Expires:
-                               return "expires";
+                               return "Expires";
                        case HttpResponseHeader.LastModified:
-                               return "last-modified";
+                               return "Last-Modified";
                        case HttpResponseHeader.AcceptRanges:
-                               return "accept-ranges";
+                               return "Accept-Ranges";
                        case HttpResponseHeader.Age:
-                               return "age";
+                               return "Age";
                        case HttpResponseHeader.ETag:
-                               return "etag";
+                               return "ETag";
                        case HttpResponseHeader.Location:
-                               return "location";
+                               return "Location";
                        case HttpResponseHeader.ProxyAuthenticate:
-                               return "proxy-authenticate";
+                               return "Proxy-Authenticate";
                        case HttpResponseHeader.RetryAfter:
-                               return "RetryAfter";
+                               return "Retry-After";
                        case HttpResponseHeader.Server:
-                               return "server";
+                               return "Server";
                        case HttpResponseHeader.SetCookie:
-                               return "set-cookie";
+                               return "Set-Cookie";
                        case HttpResponseHeader.Vary:
-                               return "vary";
+                               return "Vary";
                        case HttpResponseHeader.WwwAuthenticate:
-                               return "www-authenticate";
+                               return "WWW-Authenticate";
                        default:
                                throw new InvalidOperationException ();
                        }
                }
-               public string this[HttpResponseHeader hrh]
-               {
-                       get
-                       {
-                               return Get (ResponseHeaderToString (hrh));
-                       }
 
-                       set
-                       {
-                               Add (ResponseHeaderToString (hrh), value);
-                       }
-               }
-#endif
-
-               // Internal Methods
-               
-               // With this we don't check for invalid characters in header. See bug #55994.
-               internal void SetInternal (string header)
+               void CheckRestrictedHeader (string headerName)
                {
-                       int pos = header.IndexOf (':');
-                       if (pos == -1)
-                               throw new ArgumentException ("no colon found", "header");                               
+                       if (!headerRestriction.HasValue)
+                               return;
 
-                       SetInternal (header.Substring (0, pos), header.Substring (pos + 1));
-               }
+                       HeaderInfo info;
+                       if (!headers.TryGetValue (headerName, out info))
+                               return;
 
-               internal void SetInternal (string name, string value)
-               {
-                       if (value == null)
-                               value = String.Empty;
-                       else
-                               value = value.Trim ();
-                       if (!IsHeaderValue (value))
-                               throw new ArgumentException ("invalid header value");
-
-                       if (IsMultiValue (name)) {
-                               base.Add (name, value);
-                       } else {
-                               base.Remove (name);
-                               base.Set (name, value); 
-                       }
+                       if ((info & headerRestriction.Value) != 0)
+                               throw new ArgumentException ("This header must be modified with the appropiate property.");
                }
 
-               internal void RemoveAndAdd (string name, string value)
+               void CheckHeaderConsistency (HeaderInfo value)
                {
-                       if (value == null)
-                               value = String.Empty;
-                       else
-                               value = value.Trim ();
+                       if (!headerConsistency.HasValue) {
+                               headerConsistency = value;
+                               return;
+                       }
 
-                       base.Remove (name);
-                       base.Set (name, value);
+                       if ((headerConsistency & value) == 0)
+                               throw new InvalidOperationException ();
                }
-
-               internal void RemoveInternal (string name)
-               {
-                       if (name == null)
-                               throw new ArgumentNullException ("name");
-                       base.Remove (name);
-               }               
-               
-               // Private Methods
                
                internal static bool IsMultiValue (string headerName)
                {
-                       if (headerName == null || headerName == "")
+                       if (headerName == null)
                                return false;
 
-                       return multiValue.ContainsKey (headerName);
+                       HeaderInfo info;
+                       return headers.TryGetValue (headerName, out info) && (info & HeaderInfo.MultiValue) != 0;
                }               
                
                internal static bool IsHeaderValue (string value)
@@ -551,31 +720,17 @@ namespace System.Net
                
                internal static bool IsHeaderName (string name)
                {
-                       // token          = 1*<any CHAR except CTLs or tspecials>
-                       // tspecials      = "(" | ")" | "<" | ">" | "@"
-                       //                | "," | ";" | ":" | "\" | <">
-                       //                | "/" | "[" | "]" | "?" | "="
-                       //                | "{" | "}" | SP | HT
-                       
                        if (name == null || name.Length == 0)
                                return false;
 
                        int len = name.Length;
                        for (int i = 0; i < len; i++) {                 
                                char c = name [i];
-                               if (c < 0x20 || c >= 0x7f)
+                               if (c > 126 || !allowed_chars [c])
                                        return false;
                        }
                        
-                       return name.IndexOfAny (tspecials) == -1;
+                       return true;
                }
-
-               private static char [] tspecials = 
-                               new char [] {'(', ')', '<', '>', '@',
-                                            ',', ';', ':', '\\', '"',
-                                            '/', '[', ']', '?', '=',
-                                            '{', '}', ' ', '\t'};
-                                                       
        }
 }
-