mcs/class/System/System.Net/HttpUtility.cs

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