mcs/class/System.Web/System.Web/HttpUtility.cs

   1 //
   2 // System.Web.HttpUtility
   3 //
   4 // Authors:
   5 //   Patrik Torstensson (Patrik.Torstensson@labs2.com)
   6 //   Wictor Wilén (decode/encode functions) (wictor@ibizkit.se)
   7 //   Tim Coleman (tim@timcoleman.com)
   8 //   Gonzalo Paniagua Javier (gonzalo@ximian.com)
   9 //
  10 // Copyright (C) 2005-2009 Novell, Inc (http://www.novell.com)
  11 //
  12 // Permission is hereby granted, free of charge, to any person obtaining
  13 // a copy of this software and associated documentation files (the
  14 // "Software"), to deal in the Software without restriction, including
  15 // without limitation the rights to use, copy, modify, merge, publish,
  16 // distribute, sublicense, and/or sell copies of the Software, and to
  17 // permit persons to whom the Software is furnished to do so, subject to
  18 // the following conditions:
  19 //
  20 // The above copyright notice and this permission notice shall be
  21 // included in all copies or substantial portions of the Software.
  22 //
  23 // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
  24 // EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  25 // MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
  26 // NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
  27 // LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
  28 // OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
  29 // WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  30 //
  31
  32 using System.Collections;
  33 using System.Collections.Generic;
  34 using System.Collections.Specialized;
  35 using System.Globalization;
  36 using System.IO;
  37 using System.Security.Permissions;
  38 using System.Text;
  39 using System.Web.Util;
  40
  41 namespace System.Web {
  42
  43 #if !MONOTOUCH
  44         // CAS - no InheritanceDemand here as the class is sealed
  45         [AspNetHostingPermission (SecurityAction.LinkDemand, Level = AspNetHostingPermissionLevel.Minimal)]
  46 #endif
  47         public sealed class HttpUtility
  48         {
  49                 sealed class HttpQSCollection : NameValueCollection
  50                 {
  51                         public override string ToString ()
  52                         {
  53                                 int count = Count;
  54                                 if (count == 0)
  55                                         return "";
  56                                 StringBuilder sb = new StringBuilder ();
  57                                 string [] keys = AllKeys;
  58                                 for (int i = 0; i < count; i++) {
  59                                         sb.AppendFormat ("{0}={1}&", keys [i], this [keys [i]]);
  60                                 }
  61                                 if (sb.Length > 0)
  62                                         sb.Length--;
  63                                 return sb.ToString ();
  64                         }
  65                 }
  66                 #region Fields
  67
  68                 static Hashtable entities;
  69                 static object lock_ = new object ();
  70
  71                 #endregion // Fields
  72
  73                 static Hashtable Entities {
  74                         get {
  75                                 lock (lock_) {
  76                                         if (entities == null)
  77                                                 InitEntities ();
  78
  79                                         return entities;
  80                                 }
  81                         }
  82                 }
  83
  84                 #region Constructors
  85
  86                 static void InitEntities ()
  87                 {
  88                         // Build the hash table of HTML entity references.  This list comes
  89                         // from the HTML 4.01 W3C recommendation.
  90                         entities = new Hashtable ();
  91                         entities.Add ("nbsp", '\u00A0');
  92                         entities.Add ("iexcl", '\u00A1');
  93                         entities.Add ("cent", '\u00A2');
  94                         entities.Add ("pound", '\u00A3');
  95                         entities.Add ("curren", '\u00A4');
  96                         entities.Add ("yen", '\u00A5');
  97                         entities.Add ("brvbar", '\u00A6');
  98                         entities.Add ("sect", '\u00A7');
  99                         entities.Add ("uml", '\u00A8');
 100                         entities.Add ("copy", '\u00A9');
 101                         entities.Add ("ordf", '\u00AA');
 102                         entities.Add ("laquo", '\u00AB');
 103                         entities.Add ("not", '\u00AC');
 104                         entities.Add ("shy", '\u00AD');
 105                         entities.Add ("reg", '\u00AE');
 106                         entities.Add ("macr", '\u00AF');
 107                         entities.Add ("deg", '\u00B0');
 108                         entities.Add ("plusmn", '\u00B1');
 109                         entities.Add ("sup2", '\u00B2');
 110                         entities.Add ("sup3", '\u00B3');
 111                         entities.Add ("acute", '\u00B4');
 112                         entities.Add ("micro", '\u00B5');
 113                         entities.Add ("para", '\u00B6');
 114                         entities.Add ("middot", '\u00B7');
 115                         entities.Add ("cedil", '\u00B8');
 116                         entities.Add ("sup1", '\u00B9');
 117                         entities.Add ("ordm", '\u00BA');
 118                         entities.Add ("raquo", '\u00BB');
 119                         entities.Add ("frac14", '\u00BC');
 120                         entities.Add ("frac12", '\u00BD');
 121                         entities.Add ("frac34", '\u00BE');
 122                         entities.Add ("iquest", '\u00BF');
 123                         entities.Add ("Agrave", '\u00C0');
 124                         entities.Add ("Aacute", '\u00C1');
 125                         entities.Add ("Acirc", '\u00C2');
 126                         entities.Add ("Atilde", '\u00C3');
 127                         entities.Add ("Auml", '\u00C4');
 128                         entities.Add ("Aring", '\u00C5');
 129                         entities.Add ("AElig", '\u00C6');
 130                         entities.Add ("Ccedil", '\u00C7');
 131                         entities.Add ("Egrave", '\u00C8');
 132                         entities.Add ("Eacute", '\u00C9');
 133                         entities.Add ("Ecirc", '\u00CA');
 134                         entities.Add ("Euml", '\u00CB');
 135                         entities.Add ("Igrave", '\u00CC');
 136                         entities.Add ("Iacute", '\u00CD');
 137                         entities.Add ("Icirc", '\u00CE');
 138                         entities.Add ("Iuml", '\u00CF');
 139                         entities.Add ("ETH", '\u00D0');
 140                         entities.Add ("Ntilde", '\u00D1');
 141                         entities.Add ("Ograve", '\u00D2');
 142                         entities.Add ("Oacute", '\u00D3');
 143                         entities.Add ("Ocirc", '\u00D4');
 144                         entities.Add ("Otilde", '\u00D5');
 145                         entities.Add ("Ouml", '\u00D6');
 146                         entities.Add ("times", '\u00D7');
 147                         entities.Add ("Oslash", '\u00D8');
 148                         entities.Add ("Ugrave", '\u00D9');
 149                         entities.Add ("Uacute", '\u00DA');
 150                         entities.Add ("Ucirc", '\u00DB');
 151                         entities.Add ("Uuml", '\u00DC');
 152                         entities.Add ("Yacute", '\u00DD');
 153                         entities.Add ("THORN", '\u00DE');
 154                         entities.Add ("szlig", '\u00DF');
 155                         entities.Add ("agrave", '\u00E0');
 156                         entities.Add ("aacute", '\u00E1');
 157                         entities.Add ("acirc", '\u00E2');
 158                         entities.Add ("atilde", '\u00E3');
 159                         entities.Add ("auml", '\u00E4');
 160                         entities.Add ("aring", '\u00E5');
 161                         entities.Add ("aelig", '\u00E6');
 162                         entities.Add ("ccedil", '\u00E7');
 163                         entities.Add ("egrave", '\u00E8');
 164                         entities.Add ("eacute", '\u00E9');
 165                         entities.Add ("ecirc", '\u00EA');
 166                         entities.Add ("euml", '\u00EB');
 167                         entities.Add ("igrave", '\u00EC');
 168                         entities.Add ("iacute", '\u00ED');
 169                         entities.Add ("icirc", '\u00EE');
 170                         entities.Add ("iuml", '\u00EF');
 171                         entities.Add ("eth", '\u00F0');
 172                         entities.Add ("ntilde", '\u00F1');
 173                         entities.Add ("ograve", '\u00F2');
 174                         entities.Add ("oacute", '\u00F3');
 175                         entities.Add ("ocirc", '\u00F4');
 176                         entities.Add ("otilde", '\u00F5');
 177                         entities.Add ("ouml", '\u00F6');
 178                         entities.Add ("divide", '\u00F7');
 179                         entities.Add ("oslash", '\u00F8');
 180                         entities.Add ("ugrave", '\u00F9');
 181                         entities.Add ("uacute", '\u00FA');
 182                         entities.Add ("ucirc", '\u00FB');
 183                         entities.Add ("uuml", '\u00FC');
 184                         entities.Add ("yacute", '\u00FD');
 185                         entities.Add ("thorn", '\u00FE');
 186                         entities.Add ("yuml", '\u00FF');
 187                         entities.Add ("fnof", '\u0192');
 188                         entities.Add ("Alpha", '\u0391');
 189                         entities.Add ("Beta", '\u0392');
 190                         entities.Add ("Gamma", '\u0393');
 191                         entities.Add ("Delta", '\u0394');
 192                         entities.Add ("Epsilon", '\u0395');
 193                         entities.Add ("Zeta", '\u0396');
 194                         entities.Add ("Eta", '\u0397');
 195                         entities.Add ("Theta", '\u0398');
 196                         entities.Add ("Iota", '\u0399');
 197                         entities.Add ("Kappa", '\u039A');
 198                         entities.Add ("Lambda", '\u039B');
 199                         entities.Add ("Mu", '\u039C');
 200                         entities.Add ("Nu", '\u039D');
 201                         entities.Add ("Xi", '\u039E');
 202                         entities.Add ("Omicron", '\u039F');
 203                         entities.Add ("Pi", '\u03A0');
 204                         entities.Add ("Rho", '\u03A1');
 205                         entities.Add ("Sigma", '\u03A3');
 206                         entities.Add ("Tau", '\u03A4');
 207                         entities.Add ("Upsilon", '\u03A5');
 208                         entities.Add ("Phi", '\u03A6');
 209                         entities.Add ("Chi", '\u03A7');
 210                         entities.Add ("Psi", '\u03A8');
 211                         entities.Add ("Omega", '\u03A9');
 212                         entities.Add ("alpha", '\u03B1');
 213                         entities.Add ("beta", '\u03B2');
 214                         entities.Add ("gamma", '\u03B3');
 215                         entities.Add ("delta", '\u03B4');
 216                         entities.Add ("epsilon", '\u03B5');
 217                         entities.Add ("zeta", '\u03B6');
 218                         entities.Add ("eta", '\u03B7');
 219                         entities.Add ("theta", '\u03B8');
 220                         entities.Add ("iota", '\u03B9');
 221                         entities.Add ("kappa", '\u03BA');
 222                         entities.Add ("lambda", '\u03BB');
 223                         entities.Add ("mu", '\u03BC');
 224                         entities.Add ("nu", '\u03BD');
 225                         entities.Add ("xi", '\u03BE');
 226                         entities.Add ("omicron", '\u03BF');
 227                         entities.Add ("pi", '\u03C0');
 228                         entities.Add ("rho", '\u03C1');
 229                         entities.Add ("sigmaf", '\u03C2');
 230                         entities.Add ("sigma", '\u03C3');
 231                         entities.Add ("tau", '\u03C4');
 232                         entities.Add ("upsilon", '\u03C5');
 233                         entities.Add ("phi", '\u03C6');
 234                         entities.Add ("chi", '\u03C7');
 235                         entities.Add ("psi", '\u03C8');
 236                         entities.Add ("omega", '\u03C9');
 237                         entities.Add ("thetasym", '\u03D1');
 238                         entities.Add ("upsih", '\u03D2');
 239                         entities.Add ("piv", '\u03D6');
 240                         entities.Add ("bull", '\u2022');
 241                         entities.Add ("hellip", '\u2026');
 242                         entities.Add ("prime", '\u2032');
 243                         entities.Add ("Prime", '\u2033');
 244                         entities.Add ("oline", '\u203E');
 245                         entities.Add ("frasl", '\u2044');
 246                         entities.Add ("weierp", '\u2118');
 247                         entities.Add ("image", '\u2111');
 248                         entities.Add ("real", '\u211C');
 249                         entities.Add ("trade", '\u2122');
 250                         entities.Add ("alefsym", '\u2135');
 251                         entities.Add ("larr", '\u2190');
 252                         entities.Add ("uarr", '\u2191');
 253                         entities.Add ("rarr", '\u2192');
 254                         entities.Add ("darr", '\u2193');
 255                         entities.Add ("harr", '\u2194');
 256                         entities.Add ("crarr", '\u21B5');
 257                         entities.Add ("lArr", '\u21D0');
 258                         entities.Add ("uArr", '\u21D1');
 259                         entities.Add ("rArr", '\u21D2');
 260                         entities.Add ("dArr", '\u21D3');
 261                         entities.Add ("hArr", '\u21D4');
 262                         entities.Add ("forall", '\u2200');
 263                         entities.Add ("part", '\u2202');
 264                         entities.Add ("exist", '\u2203');
 265                         entities.Add ("empty", '\u2205');
 266                         entities.Add ("nabla", '\u2207');
 267                         entities.Add ("isin", '\u2208');
 268                         entities.Add ("notin", '\u2209');
 269                         entities.Add ("ni", '\u220B');
 270                         entities.Add ("prod", '\u220F');
 271                         entities.Add ("sum", '\u2211');
 272                         entities.Add ("minus", '\u2212');
 273                         entities.Add ("lowast", '\u2217');
 274                         entities.Add ("radic", '\u221A');
 275                         entities.Add ("prop", '\u221D');
 276                         entities.Add ("infin", '\u221E');
 277                         entities.Add ("ang", '\u2220');
 278                         entities.Add ("and", '\u2227');
 279                         entities.Add ("or", '\u2228');
 280                         entities.Add ("cap", '\u2229');
 281                         entities.Add ("cup", '\u222A');
 282                         entities.Add ("int", '\u222B');
 283                         entities.Add ("there4", '\u2234');
 284                         entities.Add ("sim", '\u223C');
 285                         entities.Add ("cong", '\u2245');
 286                         entities.Add ("asymp", '\u2248');
 287                         entities.Add ("ne", '\u2260');
 288                         entities.Add ("equiv", '\u2261');
 289                         entities.Add ("le", '\u2264');
 290                         entities.Add ("ge", '\u2265');
 291                         entities.Add ("sub", '\u2282');
 292                         entities.Add ("sup", '\u2283');
 293                         entities.Add ("nsub", '\u2284');
 294                         entities.Add ("sube", '\u2286');
 295                         entities.Add ("supe", '\u2287');
 296                         entities.Add ("oplus", '\u2295');
 297                         entities.Add ("otimes", '\u2297');
 298                         entities.Add ("perp", '\u22A5');
 299                         entities.Add ("sdot", '\u22C5');
 300                         entities.Add ("lceil", '\u2308');
 301                         entities.Add ("rceil", '\u2309');
 302                         entities.Add ("lfloor", '\u230A');
 303                         entities.Add ("rfloor", '\u230B');
 304                         entities.Add ("lang", '\u2329');
 305                         entities.Add ("rang", '\u232A');
 306                         entities.Add ("loz", '\u25CA');
 307                         entities.Add ("spades", '\u2660');
 308                         entities.Add ("clubs", '\u2663');
 309                         entities.Add ("hearts", '\u2665');
 310                         entities.Add ("diams", '\u2666');
 311                         entities.Add ("quot", '\u0022');
 312                         entities.Add ("amp", '\u0026');
 313                         entities.Add ("lt", '\u003C');
 314                         entities.Add ("gt", '\u003E');
 315                         entities.Add ("OElig", '\u0152');
 316                         entities.Add ("oelig", '\u0153');
 317                         entities.Add ("Scaron", '\u0160');
 318                         entities.Add ("scaron", '\u0161');
 319                         entities.Add ("Yuml", '\u0178');
 320                         entities.Add ("circ", '\u02C6');
 321                         entities.Add ("tilde", '\u02DC');
 322                         entities.Add ("ensp", '\u2002');
 323                         entities.Add ("emsp", '\u2003');
 324                         entities.Add ("thinsp", '\u2009');
 325                         entities.Add ("zwnj", '\u200C');
 326                         entities.Add ("zwj", '\u200D');
 327                         entities.Add ("lrm", '\u200E');
 328                         entities.Add ("rlm", '\u200F');
 329                         entities.Add ("ndash", '\u2013');
 330                         entities.Add ("mdash", '\u2014');
 331                         entities.Add ("lsquo", '\u2018');
 332                         entities.Add ("rsquo", '\u2019');
 333                         entities.Add ("sbquo", '\u201A');
 334                         entities.Add ("ldquo", '\u201C');
 335                         entities.Add ("rdquo", '\u201D');
 336                         entities.Add ("bdquo", '\u201E');
 337                         entities.Add ("dagger", '\u2020');
 338                         entities.Add ("Dagger", '\u2021');
 339                         entities.Add ("permil", '\u2030');
 340                         entities.Add ("lsaquo", '\u2039');
 341                         entities.Add ("rsaquo", '\u203A');
 342                         entities.Add ("euro", '\u20AC');
 343                 }
 344
 345                 public HttpUtility ()
 346                 {
 347                 }
 348
 349                 #endregion // Constructors
 350
 351                 #region Methods
 352
 353                 public static void HtmlAttributeEncode (string s, TextWriter output)
 354                 {
 355                         output.Write(HtmlAttributeEncode(s));
 356                 }
 357
 358                 public static string HtmlAttributeEncode (string s)
 359                 {
 360                         if (null == s)
 361                                 return null;
 362
 363                         bool needEncode = false;
 364                         for (int i = 0; i < s.Length; i++) {
 365                                 char c = s [i];
 366                                 if (c == '&' || c == '"' || c == '<'
 367 #if NET_4_0
 368                                     || c == '\''
 369 #endif
 370                                 ) {
 371                                         needEncode = true;
 372                                         break;
 373                                 }
 374                         }
 375
 376                         if (!needEncode)
 377                                 return s;
 378
 379                         StringBuilder output = new StringBuilder ();
 380                         int len = s.Length;
 381                         for (int i = 0; i < len; i++)
 382                                 switch (s [i]) {
 383                                 case '&' :
 384                                         output.Append ("&amp;");
 385                                         break;
 386                                 case '"' :
 387                                         output.Append ("&quot;");
 388                                         break;
 389                                 case '<':
 390                                         output.Append ("&lt;");
 391                                         break;
 392 #if NET_4_0
 393                                 case '\'':
 394                                         output.Append ("&#39;");
 395                                         break;
 396 #endif
 397                                 default:
 398                                         output.Append (s [i]);
 399                                         break;
 400                                 }
 401
 402                         return output.ToString();
 403                 }
 404
 405                 public static string UrlDecode (string str)
 406                 {
 407                         return UrlDecode(str, Encoding.UTF8);
 408                 }
 409
 410                 static char [] GetChars (MemoryStream b, Encoding e)
 411                 {
 412                         return e.GetChars (b.GetBuffer (), 0, (int) b.Length);
 413                 }
 414
 415                 static void WriteCharBytes (IList buf, char ch, Encoding e)
 416                 {
 417                         if (ch > 255) {
 418                                 foreach (byte b in e.GetBytes (new char[] { ch }))
 419                                         buf.Add (b);
 420                         } else
 421                                 buf.Add ((byte)ch);
 422                 }
 423
 424                 public static string UrlDecode (string s, Encoding e)
 425                 {
 426                         if (null == s)
 427                                 return null;
 428
 429                         if (s.IndexOf ('%') == -1 && s.IndexOf ('+') == -1)
 430                                 return s;
 431
 432                         if (e == null)
 433                                 e = Encoding.UTF8;
 434
 435                         long len = s.Length;
 436                         var bytes = new List <byte> ();
 437                         int xchar;
 438                         char ch;
 439
 440                         for (int i = 0; i < len; i++) {
 441                                 ch = s [i];
 442                                 if (ch == '%' && i + 2 < len && s [i + 1] != '%') {
 443                                         if (s [i + 1] == 'u' && i + 5 < len) {
 444                                                 // unicode hex sequence
 445                                                 xchar = GetChar (s, i + 2, 4);
 446                                                 if (xchar != -1) {
 447                                                         WriteCharBytes (bytes, (char)xchar, e);
 448                                                         i += 5;
 449                                                 } else
 450                                                         WriteCharBytes (bytes, '%', e);
 451                                         } else if ((xchar = GetChar (s, i + 1, 2)) != -1) {
 452                                                 WriteCharBytes (bytes, (char)xchar, e);
 453                                                 i += 2;
 454                                         } else {
 455                                                 WriteCharBytes (bytes, '%', e);
 456                                         }
 457                                         continue;
 458                                 }
 459
 460                                 if (ch == '+')
 461                                         WriteCharBytes (bytes, ' ', e);
 462                                 else
 463                                         WriteCharBytes (bytes, ch, e);
 464                         }
 465
 466                         byte[] buf = bytes.ToArray ();
 467                         bytes = null;
 468                         return e.GetString (buf);
 469
 470                 }
 471
 472                 public static string UrlDecode (byte [] bytes, Encoding e)
 473                 {
 474                         if (bytes == null)
 475                                 return null;
 476
 477                         return UrlDecode (bytes, 0, bytes.Length, e);
 478                 }
 479
 480                 static int GetInt (byte b)
 481                 {
 482                         char c = (char) b;
 483                         if (c >= '0' && c <= '9')
 484                                 return c - '0';
 485
 486                         if (c >= 'a' && c <= 'f')
 487                                 return c - 'a' + 10;
 488
 489                         if (c >= 'A' && c <= 'F')
 490                                 return c - 'A' + 10;
 491
 492                         return -1;
 493                 }
 494
 495                 static int GetChar (byte [] bytes, int offset, int length)
 496                 {
 497                         int value = 0;
 498                         int end = length + offset;
 499                         for (int i = offset; i < end; i++) {
 500                                 int current = GetInt (bytes [i]);
 501                                 if (current == -1)
 502                                         return -1;
 503                                 value = (value << 4) + current;
 504                         }
 505
 506                         return value;
 507                 }
 508
 509                 static int GetChar (string str, int offset, int length)
 510                 {
 511                         int val = 0;
 512                         int end = length + offset;
 513                         for (int i = offset; i < end; i++) {
 514                                 char c = str [i];
 515                                 if (c > 127)
 516                                         return -1;
 517
 518                                 int current = GetInt ((byte) c);
 519                                 if (current == -1)
 520                                         return -1;
 521                                 val = (val << 4) + current;
 522                         }
 523
 524                         return val;
 525                 }
 526
 527                 public static string UrlDecode (byte [] bytes, int offset, int count, Encoding e)
 528                 {
 529                         if (bytes == null)
 530                                 return null;
 531                         if (count == 0)
 532                                 return String.Empty;
 533
 534                         if (bytes == null)
 535                                 throw new ArgumentNullException ("bytes");
 536
 537                         if (offset < 0 || offset > bytes.Length)
 538                                 throw new ArgumentOutOfRangeException ("offset");
 539
 540                         if (count < 0 || offset + count > bytes.Length)
 541                                 throw new ArgumentOutOfRangeException ("count");
 542
 543                         StringBuilder output = new StringBuilder ();
 544                         MemoryStream acc = new MemoryStream ();
 545
 546                         int end = count + offset;
 547                         int xchar;
 548                         for (int i = offset; i < end; i++) {
 549                                 if (bytes [i] == '%' && i + 2 < count && bytes [i + 1] != '%') {
 550                                         if (bytes [i + 1] == (byte) 'u' && i + 5 < end) {
 551                                                 if (acc.Length > 0) {
 552                                                         output.Append (GetChars (acc, e));
 553                                                         acc.SetLength (0);
 554                                                 }
 555                                                 xchar = GetChar (bytes, i + 2, 4);
 556                                                 if (xchar != -1) {
 557                                                         output.Append ((char) xchar);
 558                                                         i += 5;
 559                                                         continue;
 560                                                 }
 561                                         } else if ((xchar = GetChar (bytes, i + 1, 2)) != -1) {
 562                                                 acc.WriteByte ((byte) xchar);
 563                                                 i += 2;
 564                                                 continue;
 565                                         }
 566                                 }
 567
 568                                 if (acc.Length > 0) {
 569                                         output.Append (GetChars (acc, e));
 570                                         acc.SetLength (0);
 571                                 }
 572
 573                                 if (bytes [i] == '+') {
 574                                         output.Append (' ');
 575                                 } else {
 576                                         output.Append ((char) bytes [i]);
 577                                 }
 578                         }
 579
 580                         if (acc.Length > 0) {
 581                                 output.Append (GetChars (acc, e));
 582                         }
 583
 584                         acc = null;
 585                         return output.ToString ();
 586                 }
 587
 588                 public static byte [] UrlDecodeToBytes (byte [] bytes)
 589                 {
 590                         if (bytes == null)
 591                                 return null;
 592
 593                         return UrlDecodeToBytes (bytes, 0, bytes.Length);
 594                 }
 595
 596                 public static byte [] UrlDecodeToBytes (string str)
 597                 {
 598                         return UrlDecodeToBytes (str, Encoding.UTF8);
 599                 }
 600
 601                 public static byte [] UrlDecodeToBytes (string str, Encoding e)
 602                 {
 603                         if (str == null)
 604                                 return null;
 605
 606                         if (e == null)
 607                                 throw new ArgumentNullException ("e");
 608
 609                         return UrlDecodeToBytes (e.GetBytes (str));
 610                 }
 611
 612                 public static byte [] UrlDecodeToBytes (byte [] bytes, int offset, int count)
 613                 {
 614                         if (bytes == null)
 615                                 return null;
 616                         if (count == 0)
 617                                 return new byte [0];
 618
 619                         int len = bytes.Length;
 620                         if (offset < 0 || offset >= len)
 621                                 throw new ArgumentOutOfRangeException("offset");
 622
 623                         if (count < 0 || offset > len - count)
 624                                 throw new ArgumentOutOfRangeException("count");
 625
 626                         MemoryStream result = new MemoryStream ();
 627                         int end = offset + count;
 628                         for (int i = offset; i < end; i++){
 629                                 char c = (char) bytes [i];
 630                                 if (c == '+') {
 631                                         c = ' ';
 632                                 } else if (c == '%' && i < end - 2) {
 633                                         int xchar = GetChar (bytes, i + 1, 2);
 634                                         if (xchar != -1) {
 635                                                 c = (char) xchar;
 636                                                 i += 2;
 637                                         }
 638                                 }
 639                                 result.WriteByte ((byte) c);
 640                         }
 641
 642                         return result.ToArray ();
 643                 }
 644
 645                 public static string UrlEncode(string str)
 646                 {
 647                         return UrlEncode(str, Encoding.UTF8);
 648                 }
 649
 650                 public static string UrlEncode (string s, Encoding Enc)
 651                 {
 652                         if (s == null)
 653                                 return null;
 654
 655                         if (s == String.Empty)
 656                                 return String.Empty;
 657
 658                         bool needEncode = false;
 659                         int len = s.Length;
 660                         for (int i = 0; i < len; i++) {
 661                                 char c = s [i];
 662                                 if ((c < '0') || (c < 'A' && c > '9') || (c > 'Z' && c < 'a') || (c > 'z')) {
 663                                         if (NotEncoded (c))
 664                                                 continue;
 665
 666                                         needEncode = true;
 667                                         break;
 668                                 }
 669                         }
 670
 671                         if (!needEncode)
 672                                 return s;
 673
 674                         // avoided GetByteCount call
 675                         byte [] bytes = new byte[Enc.GetMaxByteCount(s.Length)];
 676                         int realLen = Enc.GetBytes (s, 0, s.Length, bytes, 0);
 677                         return Encoding.ASCII.GetString (UrlEncodeToBytes (bytes, 0, realLen));
 678                 }
 679
 680                 public static string UrlEncode (byte [] bytes)
 681                 {
 682                         if (bytes == null)
 683                                 return null;
 684
 685                         if (bytes.Length == 0)
 686                                 return "";
 687
 688                         return Encoding.ASCII.GetString (UrlEncodeToBytes (bytes, 0, bytes.Length));
 689                 }
 690
 691                 public static string UrlEncode (byte [] bytes, int offset, int count)
 692                 {
 693                         if (bytes == null)
 694                                 return null;
 695
 696                         if (bytes.Length == 0)
 697                                 return "";
 698
 699                         return Encoding.ASCII.GetString (UrlEncodeToBytes (bytes, offset, count));
 700                 }
 701
 702                 public static byte [] UrlEncodeToBytes (string str)
 703                 {
 704                         return UrlEncodeToBytes (str, Encoding.UTF8);
 705                 }
 706
 707                 public static byte [] UrlEncodeToBytes (string str, Encoding e)
 708                 {
 709                         if (str == null)
 710                                 return null;
 711
 712                         if (str == "")
 713                                 return new byte [0];
 714
 715                         byte [] bytes = e.GetBytes (str);
 716                         return UrlEncodeToBytes (bytes, 0, bytes.Length);
 717                 }
 718
 719                 public static byte [] UrlEncodeToBytes (byte [] bytes)
 720                 {
 721                         if (bytes == null)
 722                                 return null;
 723
 724                         if (bytes.Length == 0)
 725                                 return new byte [0];
 726
 727                         return UrlEncodeToBytes (bytes, 0, bytes.Length);
 728                 }
 729
 730                 static char [] hexChars = "0123456789abcdef".ToCharArray ();
 731
 732                 static bool NotEncoded (char c)
 733                 {
 734                         return (c == '!' || c == '(' || c == ')' || c == '*' || c == '-' || c == '.' || c == '_'
 735 #if !NET_4_0
 736                                 || c == '\''
 737 #endif
 738                         );
 739                 }
 740
 741                 static void UrlEncodeChar (char c, Stream result, bool isUnicode) {
 742                         if (c > 255) {
 743                                 //FIXME: what happens when there is an internal error?
 744                                 //if (!isUnicode)
 745                                 //      throw new ArgumentOutOfRangeException ("c", c, "c must be less than 256");
 746                                 int idx;
 747                                 int i = (int) c;
 748
 749                                 result.WriteByte ((byte)'%');
 750                                 result.WriteByte ((byte)'u');
 751                                 idx = i >> 12;
 752                                 result.WriteByte ((byte)hexChars [idx]);
 753                                 idx = (i >> 8) & 0x0F;
 754                                 result.WriteByte ((byte)hexChars [idx]);
 755                                 idx = (i >> 4) & 0x0F;
 756                                 result.WriteByte ((byte)hexChars [idx]);
 757                                 idx = i & 0x0F;
 758                                 result.WriteByte ((byte)hexChars [idx]);
 759                                 return;
 760                         }
 761
 762                         if (c > ' ' && NotEncoded (c)) {
 763                                 result.WriteByte ((byte)c);
 764                                 return;
 765                         }
 766                         if (c==' ') {
 767                                 result.WriteByte ((byte)'+');
 768                                 return;
 769                         }
 770                         if (    (c < '0') ||
 771                                 (c < 'A' && c > '9') ||
 772                                 (c > 'Z' && c < 'a') ||
 773                                 (c > 'z')) {
 774                                 if (isUnicode && c > 127) {
 775                                         result.WriteByte ((byte)'%');
 776                                         result.WriteByte ((byte)'u');
 777                                         result.WriteByte ((byte)'0');
 778                                         result.WriteByte ((byte)'0');
 779                                 }
 780                                 else
 781                                         result.WriteByte ((byte)'%');
 782
 783                                 int idx = ((int) c) >> 4;
 784                                 result.WriteByte ((byte)hexChars [idx]);
 785                                 idx = ((int) c) & 0x0F;
 786                                 result.WriteByte ((byte)hexChars [idx]);
 787                         }
 788                         else
 789                                 result.WriteByte ((byte)c);
 790                 }
 791
 792                 public static byte [] UrlEncodeToBytes (byte [] bytes, int offset, int count)
 793                 {
 794                         if (bytes == null)
 795                                 return null;
 796
 797                         int len = bytes.Length;
 798                         if (len == 0)
 799                                 return new byte [0];
 800
 801                         if (offset < 0 || offset >= len)
 802                                 throw new ArgumentOutOfRangeException("offset");
 803
 804                         if (count < 0 || count > len - offset)
 805                                 throw new ArgumentOutOfRangeException("count");
 806
 807                         MemoryStream result = new MemoryStream (count);
 808                         int end = offset + count;
 809                         for (int i = offset; i < end; i++)
 810                                 UrlEncodeChar ((char)bytes [i], result, false);
 811
 812                         return result.ToArray();
 813                 }
 814
 815                 public static string UrlEncodeUnicode (string str)
 816                 {
 817                         if (str == null)
 818                                 return null;
 819
 820                         return Encoding.ASCII.GetString (UrlEncodeUnicodeToBytes (str));
 821                 }
 822
 823                 public static byte [] UrlEncodeUnicodeToBytes (string str)
 824                 {
 825                         if (str == null)
 826                                 return null;
 827
 828                         if (str == "")
 829                                 return new byte [0];
 830
 831                         MemoryStream result = new MemoryStream (str.Length);
 832                         foreach (char c in str){
 833                                 UrlEncodeChar (c, result, true);
 834                         }
 835                         return result.ToArray ();
 836                 }
 837
 838                 /// <summary>
 839                 /// Decodes an HTML-encoded string and returns the decoded string.
 840                 /// </summary>
 841                 /// <param name="s">The HTML string to decode. </param>
 842                 /// <returns>The decoded text.</returns>
 843                 public static string HtmlDecode (string s)
 844                 {
 845                         if (s == null)
 846                                 throw new ArgumentNullException ("s");
 847
 848                         if (s.IndexOf ('&') == -1)
 849                                 return s;
 850
 851                         StringBuilder entity = new StringBuilder ();
 852                         StringBuilder output = new StringBuilder ();
 853                         int len = s.Length;
 854                         // 0 -> nothing,
 855                         // 1 -> right after '&'
 856                         // 2 -> between '&' and ';' but no '#'
 857                         // 3 -> '#' found after '&' and getting numbers
 858                         int state = 0;
 859                         int number = 0;
 860                         bool is_hex_value = false;
 861                         bool have_trailing_digits = false;
 862
 863                         for (int i = 0; i < len; i++) {
 864                                 char c = s [i];
 865                                 if (state == 0) {
 866                                         if (c == '&') {
 867                                                 entity.Append (c);
 868                                                 state = 1;
 869                                         } else {
 870                                                 output.Append (c);
 871                                         }
 872                                         continue;
 873                                 }
 874
 875                                 if (c == '&') {
 876                                         state = 1;
 877                                         if (have_trailing_digits) {
 878                                                 entity.Append (number.ToString (Helpers.InvariantCulture));
 879                                                 have_trailing_digits = false;
 880                                         }
 881
 882                                         output.Append (entity.ToString ());
 883                                         entity.Length = 0;
 884                                         entity.Append ('&');
 885                                         continue;
 886                                 }
 887
 888                                 if (state == 1) {
 889                                         if (c == ';') {
 890                                                 state = 0;
 891                                                 output.Append (entity.ToString ());
 892                                                 output.Append (c);
 893                                                 entity.Length = 0;
 894                                         } else {
 895                                                 number = 0;
 896                                                 is_hex_value = false;
 897                                                 if (c != '#') {
 898                                                         state = 2;
 899                                                 } else {
 900                                                         state = 3;
 901                                                 }
 902                                                 entity.Append (c);
 903                                         }
 904                                 } else if (state == 2) {
 905                                         entity.Append (c);
 906                                         if (c == ';') {
 907                                                 string key = entity.ToString ();
 908                                                 if (key.Length > 1 && Entities.ContainsKey (key.Substring (1, key.Length - 2)))
 909                                                         key = Entities [key.Substring (1, key.Length - 2)].ToString ();
 910
 911                                                 output.Append (key);
 912                                                 state = 0;
 913                                                 entity.Length = 0;
 914                                         }
 915                                 } else if (state == 3) {
 916                                         if (c == ';') {
 917                                                 if (number > 65535) {
 918                                                         output.Append ("&#");
 919                                                         output.Append (number.ToString (Helpers.InvariantCulture));
 920                                                         output.Append (";");
 921                                                 } else {
 922                                                         output.Append ((char) number);
 923                                                 }
 924                                                 state = 0;
 925                                                 entity.Length = 0;
 926                                                 have_trailing_digits = false;
 927                                         } else if (is_hex_value &&  Uri.IsHexDigit(c)) {
 928                                                 number = number * 16 + Uri.FromHex(c);
 929                                                 have_trailing_digits = true;
 930                                         } else if (Char.IsDigit (c)) {
 931                                                 number = number * 10 + ((int) c - '0');
 932                                                 have_trailing_digits = true;
 933                                         } else if (number == 0 && (c == 'x' || c == 'X')) {
 934                                                 is_hex_value = true;
 935                                         } else {
 936                                                 state = 2;
 937                                                 if (have_trailing_digits) {
 938                                                         entity.Append (number.ToString (Helpers.InvariantCulture));
 939                                                         have_trailing_digits = false;
 940                                                 }
 941                                                 entity.Append (c);
 942                                         }
 943                                 }
 944                         }
 945
 946                         if (entity.Length > 0) {
 947                                 output.Append (entity.ToString ());
 948                         } else if (have_trailing_digits) {
 949                                 output.Append (number.ToString (Helpers.InvariantCulture));
 950                         }
 951                         return output.ToString ();
 952                 }
 953
 954                 /// <summary>
 955                 /// Decodes an HTML-encoded string and sends the resulting output to a TextWriter output stream.
 956                 /// </summary>
 957                 /// <param name="s">The HTML string to decode</param>
 958                 /// <param name="output">The TextWriter output stream containing the decoded string. </param>
 959                 public static void HtmlDecode(string s, TextWriter output)
 960                 {
 961                         if (s != null)
 962                                 output.Write (HtmlDecode (s));
 963                 }
 964
 965                 /// <summary>
 966                 /// HTML-encodes a string and returns the encoded string.
 967                 /// </summary>
 968                 /// <param name="s">The text string to encode. </param>
 969                 /// <returns>The HTML-encoded text.</returns>
 970                 public static string HtmlEncode (string s)
 971                 {
 972                         if (s == null)
 973                                 return null;
 974
 975                         bool needEncode = false;
 976                         for (int i = 0; i < s.Length; i++) {
 977                                 char c = s [i];
 978                                 if (c == '&' || c == '"' || c == '<' || c == '>' || c > 159
 979 #if NET_4_0
 980                                     || c == '\''
 981 #endif
 982                                 ) {
 983                                         needEncode = true;
 984                                         break;
 985                                 }
 986                         }
 987
 988                         if (!needEncode)
 989                                 return s;
 990
 991                         StringBuilder output = new StringBuilder ();
 992
 993                         int len = s.Length;
 994                         for (int i = 0; i < len; i++)
 995                                 switch (s [i]) {
 996                                 case '&' :
 997                                         output.Append ("&amp;");
 998                                         break;
 999                                 case '>' :
1000                                         output.Append ("&gt;");
1001                                         break;
1002                                 case '<' :
1003                                         output.Append ("&lt;");
1004                                         break;
1005                                 case '"' :
1006                                         output.Append ("&quot;");
1007                                         break;
1008 #if NET_4_0
1009                                 case '\'':
1010                                         output.Append ("&#39;");
1011                                         break;
1012 #endif
1013                                 default:
1014                                         // MS starts encoding with &# from 160 and stops at 255.
1015                                         // We don't do that. One reason is the 65308/65310 unicode
1016                                         // characters that look like '<' and '>'.
1017 #if TARGET_JVM
1018                                         if (s [i] > 159 && s [i] < 256) {
1019 #else
1020                                         if (s [i] > 159) {
1021 #endif
1022                                                 output.Append ("&#");
1023                                                 output.Append (((int) s [i]).ToString (Helpers.InvariantCulture));
1024                                                 output.Append (";");
1025                                         } else {
1026                                                 output.Append (s [i]);
1027                                         }
1028                                         break;
1029                                 }
1030                         return output.ToString ();
1031                 }
1032
1033                 /// <summary>
1034                 /// HTML-encodes a string and sends the resulting output to a TextWriter output stream.
1035                 /// </summary>
1036                 /// <param name="s">The string to encode. </param>
1037                 /// <param name="output">The TextWriter output stream containing the encoded string. </param>
1038                 public static void HtmlEncode(string s, TextWriter output)
1039                 {
1040                         if (s != null)
1041                                 output.Write (HtmlEncode (s));
1042                 }
1043 #if NET_4_0
1044                 public static string HtmlEncode (object value)
1045                 {
1046                         if (value == null)
1047                                 return null;
1048
1049                         return HtmlEncode (value.ToString ());
1050                 }
1051
1052                 public static string JavaScriptStringEncode (string value)
1053                 {
1054                         return JavaScriptStringEncode (value, false);
1055                 }
1056
1057                 public static string JavaScriptStringEncode (string value, bool addDoubleQuotes)
1058                 {
1059                         if (String.IsNullOrEmpty (value))
1060                                 return addDoubleQuotes ? "\"\"" : String.Empty;
1061
1062                         int len = value.Length;
1063                         bool needEncode = false;
1064                         char c;
1065                         for (int i = 0; i < len; i++) {
1066                                 c = value [i];
1067
1068                                 if (c >= 0 && c <= 31 || c == 34 || c == 39 || c == 60 || c == 62 || c == 92) {
1069                                         needEncode = true;
1070                                         break;
1071                                 }
1072                         }
1073
1074                         if (!needEncode)
1075                                 return addDoubleQuotes ? "\"" + value + "\"" : value;
1076
1077                         var sb = new StringBuilder ();
1078                         if (addDoubleQuotes)
1079                                 sb.Append ('"');
1080
1081                         for (int i = 0; i < len; i++) {
1082                                 c = value [i];
1083                                 if (c >= 0 && c <= 7 || c == 11 || c >= 14 && c <= 31 || c == 39 || c == 60 || c == 62)
1084                                         sb.AppendFormat ("\\u{0:x4}", (int)c);
1085                                 else switch ((int)c) {
1086                                                 case 8:
1087                                                         sb.Append ("\\b");
1088                                                         break;
1089
1090                                                 case 9:
1091                                                         sb.Append ("\\t");
1092                                                         break;
1093
1094                                                 case 10:
1095                                                         sb.Append ("\\n");
1096                                                         break;
1097
1098                                                 case 12:
1099                                                         sb.Append ("\\f");
1100                                                         break;
1101
1102                                                 case 13:
1103                                                         sb.Append ("\\r");
1104                                                         break;
1105
1106                                                 case 34:
1107                                                         sb.Append ("\\\"");
1108                                                         break;
1109
1110                                                 case 92:
1111                                                         sb.Append ("\\\\");
1112                                                         break;
1113
1114                                                 default:
1115                                                         sb.Append (c);
1116                                                         break;
1117                                         }
1118                         }
1119
1120                         if (addDoubleQuotes)
1121                                 sb.Append ('"');
1122
1123                         return sb.ToString ();
1124                 }
1125 #endif
1126                 public static string UrlPathEncode (string s)
1127                 {
1128                         if (s == null || s.Length == 0)
1129                                 return s;
1130
1131                         MemoryStream result = new MemoryStream ();
1132                         int length = s.Length;
1133                         for (int i = 0; i < length; i++) {
1134                                 UrlPathEncodeChar (s [i], result);
1135                         }
1136                         return Encoding.ASCII.GetString (result.ToArray ());
1137                 }
1138
1139                 static void UrlPathEncodeChar (char c, Stream result)
1140                 {
1141                         if (c < 33 || c > 126) {
1142                                 byte [] bIn = Encoding.UTF8.GetBytes (c.ToString ());
1143                                 for (int i = 0; i < bIn.Length; i++) {
1144                                         result.WriteByte ((byte) '%');
1145                                         int idx = ((int) bIn [i]) >> 4;
1146                                         result.WriteByte ((byte) hexChars [idx]);
1147                                         idx = ((int) bIn [i]) & 0x0F;
1148                                         result.WriteByte ((byte) hexChars [idx]);
1149                                 }
1150                         }
1151                         else if (c == ' ') {
1152                                 result.WriteByte ((byte) '%');
1153                                 result.WriteByte ((byte) '2');
1154                                 result.WriteByte ((byte) '0');
1155                         }
1156                         else
1157                                 result.WriteByte ((byte) c);
1158                 }
1159
1160                 public static NameValueCollection ParseQueryString (string query)
1161                 {
1162                         return ParseQueryString (query, Encoding.UTF8);
1163                 }
1164
1165                 public static NameValueCollection ParseQueryString (string query, Encoding encoding)
1166                 {
1167                         if (query == null)
1168                                 throw new ArgumentNullException ("query");
1169                         if (encoding == null)
1170                                 throw new ArgumentNullException ("encoding");
1171                         if (query.Length == 0 || (query.Length == 1 && query[0] == '?'))
1172                                 return new NameValueCollection ();
1173                         if (query[0] == '?')
1174                                 query = query.Substring (1);
1175
1176                         NameValueCollection result = new HttpQSCollection ();
1177                         ParseQueryString (query, encoding, result);
1178                         return result;
1179                 }
1180
1181                 internal static void ParseQueryString (string query, Encoding encoding, NameValueCollection result)
1182                 {
1183                         if (query.Length == 0)
1184                                 return;
1185
1186                         string decoded = HtmlDecode (query);
1187                         int decodedLength = decoded.Length;
1188                         int namePos = 0;
1189                         bool first = true;
1190                         while (namePos <= decodedLength) {
1191                                 int valuePos = -1, valueEnd = -1;
1192                                 for (int q = namePos; q < decodedLength; q++) {
1193                                         if (valuePos == -1 && decoded [q] == '=') {
1194                                                 valuePos = q + 1;
1195                                         } else if (decoded [q] == '&') {
1196                                                 valueEnd = q;
1197                                                 break;
1198                                         }
1199                                 }
1200
1201                                 if (first) {
1202                                         first = false;
1203                                         if (decoded [namePos] == '?')
1204                                                 namePos++;
1205                                 }
1206
1207                                 string name, value;
1208                                 if (valuePos == -1) {
1209                                         name = null;
1210                                         valuePos = namePos;
1211                                 } else {
1212                                         name = UrlDecode (decoded.Substring (namePos, valuePos - namePos - 1), encoding);
1213                                 }
1214                                 if (valueEnd < 0) {
1215                                         namePos = -1;
1216                                         valueEnd = decoded.Length;
1217                                 } else {
1218                                         namePos = valueEnd + 1;
1219                                 }
1220                                 value = UrlDecode (decoded.Substring (valuePos, valueEnd - valuePos), encoding);
1221
1222                                 result.Add (name, value);
1223                                 if (namePos == -1)
1224                                         break;
1225                         }
1226                 }
1227                 #endregion // Methods
1228         }
1229 }
1230