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 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.Specialized;
  34 using System.Globalization;
  35 using System.IO;
  36 using System.Security.Permissions;
  37 using System.Text;
  38 using System.Web.Util;
  39
  40 namespace System.Web {
  41
  42         // CAS - no InheritanceDemand here as the class is sealed
  43         [AspNetHostingPermission (SecurityAction.LinkDemand, Level = AspNetHostingPermissionLevel.Minimal)]
  44         public sealed class HttpUtility {
  45                 #region Fields
  46
  47                 static Hashtable entities;
  48                 static object lock_ = new object ();
  49
  50                 #endregion // Fields
  51
  52                 static Hashtable Entities {
  53                         get {
  54                                 lock (lock_) {
  55                                         if (entities == null)
  56                                                 InitEntities ();
  57
  58                                         return entities;
  59                                 }
  60                         }
  61                 }
  62
  63                 #region Constructors
  64
  65                 static void InitEntities ()
  66                 {
  67                         // Build the hash table of HTML entity references.  This list comes
  68                         // from the HTML 4.01 W3C recommendation.
  69                         entities = new Hashtable ();
  70                         entities.Add ("nbsp", '\u00A0');
  71                         entities.Add ("iexcl", '\u00A1');
  72                         entities.Add ("cent", '\u00A2');
  73                         entities.Add ("pound", '\u00A3');
  74                         entities.Add ("curren", '\u00A4');
  75                         entities.Add ("yen", '\u00A5');
  76                         entities.Add ("brvbar", '\u00A6');
  77                         entities.Add ("sect", '\u00A7');
  78                         entities.Add ("uml", '\u00A8');
  79                         entities.Add ("copy", '\u00A9');
  80                         entities.Add ("ordf", '\u00AA');
  81                         entities.Add ("laquo", '\u00AB');
  82                         entities.Add ("not", '\u00AC');
  83                         entities.Add ("shy", '\u00AD');
  84                         entities.Add ("reg", '\u00AE');
  85                         entities.Add ("macr", '\u00AF');
  86                         entities.Add ("deg", '\u00B0');
  87                         entities.Add ("plusmn", '\u00B1');
  88                         entities.Add ("sup2", '\u00B2');
  89                         entities.Add ("sup3", '\u00B3');
  90                         entities.Add ("acute", '\u00B4');
  91                         entities.Add ("micro", '\u00B5');
  92                         entities.Add ("para", '\u00B6');
  93                         entities.Add ("middot", '\u00B7');
  94                         entities.Add ("cedil", '\u00B8');
  95                         entities.Add ("sup1", '\u00B9');
  96                         entities.Add ("ordm", '\u00BA');
  97                         entities.Add ("raquo", '\u00BB');
  98                         entities.Add ("frac14", '\u00BC');
  99                         entities.Add ("frac12", '\u00BD');
 100                         entities.Add ("frac34", '\u00BE');
 101                         entities.Add ("iquest", '\u00BF');
 102                         entities.Add ("Agrave", '\u00C0');
 103                         entities.Add ("Aacute", '\u00C1');
 104                         entities.Add ("Acirc", '\u00C2');
 105                         entities.Add ("Atilde", '\u00C3');
 106                         entities.Add ("Auml", '\u00C4');
 107                         entities.Add ("Aring", '\u00C5');
 108                         entities.Add ("AElig", '\u00C6');
 109                         entities.Add ("Ccedil", '\u00C7');
 110                         entities.Add ("Egrave", '\u00C8');
 111                         entities.Add ("Eacute", '\u00C9');
 112                         entities.Add ("Ecirc", '\u00CA');
 113                         entities.Add ("Euml", '\u00CB');
 114                         entities.Add ("Igrave", '\u00CC');
 115                         entities.Add ("Iacute", '\u00CD');
 116                         entities.Add ("Icirc", '\u00CE');
 117                         entities.Add ("Iuml", '\u00CF');
 118                         entities.Add ("ETH", '\u00D0');
 119                         entities.Add ("Ntilde", '\u00D1');
 120                         entities.Add ("Ograve", '\u00D2');
 121                         entities.Add ("Oacute", '\u00D3');
 122                         entities.Add ("Ocirc", '\u00D4');
 123                         entities.Add ("Otilde", '\u00D5');
 124                         entities.Add ("Ouml", '\u00D6');
 125                         entities.Add ("times", '\u00D7');
 126                         entities.Add ("Oslash", '\u00D8');
 127                         entities.Add ("Ugrave", '\u00D9');
 128                         entities.Add ("Uacute", '\u00DA');
 129                         entities.Add ("Ucirc", '\u00DB');
 130                         entities.Add ("Uuml", '\u00DC');
 131                         entities.Add ("Yacute", '\u00DD');
 132                         entities.Add ("THORN", '\u00DE');
 133                         entities.Add ("szlig", '\u00DF');
 134                         entities.Add ("agrave", '\u00E0');
 135                         entities.Add ("aacute", '\u00E1');
 136                         entities.Add ("acirc", '\u00E2');
 137                         entities.Add ("atilde", '\u00E3');
 138                         entities.Add ("auml", '\u00E4');
 139                         entities.Add ("aring", '\u00E5');
 140                         entities.Add ("aelig", '\u00E6');
 141                         entities.Add ("ccedil", '\u00E7');
 142                         entities.Add ("egrave", '\u00E8');
 143                         entities.Add ("eacute", '\u00E9');
 144                         entities.Add ("ecirc", '\u00EA');
 145                         entities.Add ("euml", '\u00EB');
 146                         entities.Add ("igrave", '\u00EC');
 147                         entities.Add ("iacute", '\u00ED');
 148                         entities.Add ("icirc", '\u00EE');
 149                         entities.Add ("iuml", '\u00EF');
 150                         entities.Add ("eth", '\u00F0');
 151                         entities.Add ("ntilde", '\u00F1');
 152                         entities.Add ("ograve", '\u00F2');
 153                         entities.Add ("oacute", '\u00F3');
 154                         entities.Add ("ocirc", '\u00F4');
 155                         entities.Add ("otilde", '\u00F5');
 156                         entities.Add ("ouml", '\u00F6');
 157                         entities.Add ("divide", '\u00F7');
 158                         entities.Add ("oslash", '\u00F8');
 159                         entities.Add ("ugrave", '\u00F9');
 160                         entities.Add ("uacute", '\u00FA');
 161                         entities.Add ("ucirc", '\u00FB');
 162                         entities.Add ("uuml", '\u00FC');
 163                         entities.Add ("yacute", '\u00FD');
 164                         entities.Add ("thorn", '\u00FE');
 165                         entities.Add ("yuml", '\u00FF');
 166                         entities.Add ("fnof", '\u0192');
 167                         entities.Add ("Alpha", '\u0391');
 168                         entities.Add ("Beta", '\u0392');
 169                         entities.Add ("Gamma", '\u0393');
 170                         entities.Add ("Delta", '\u0394');
 171                         entities.Add ("Epsilon", '\u0395');
 172                         entities.Add ("Zeta", '\u0396');
 173                         entities.Add ("Eta", '\u0397');
 174                         entities.Add ("Theta", '\u0398');
 175                         entities.Add ("Iota", '\u0399');
 176                         entities.Add ("Kappa", '\u039A');
 177                         entities.Add ("Lambda", '\u039B');
 178                         entities.Add ("Mu", '\u039C');
 179                         entities.Add ("Nu", '\u039D');
 180                         entities.Add ("Xi", '\u039E');
 181                         entities.Add ("Omicron", '\u039F');
 182                         entities.Add ("Pi", '\u03A0');
 183                         entities.Add ("Rho", '\u03A1');
 184                         entities.Add ("Sigma", '\u03A3');
 185                         entities.Add ("Tau", '\u03A4');
 186                         entities.Add ("Upsilon", '\u03A5');
 187                         entities.Add ("Phi", '\u03A6');
 188                         entities.Add ("Chi", '\u03A7');
 189                         entities.Add ("Psi", '\u03A8');
 190                         entities.Add ("Omega", '\u03A9');
 191                         entities.Add ("alpha", '\u03B1');
 192                         entities.Add ("beta", '\u03B2');
 193                         entities.Add ("gamma", '\u03B3');
 194                         entities.Add ("delta", '\u03B4');
 195                         entities.Add ("epsilon", '\u03B5');
 196                         entities.Add ("zeta", '\u03B6');
 197                         entities.Add ("eta", '\u03B7');
 198                         entities.Add ("theta", '\u03B8');
 199                         entities.Add ("iota", '\u03B9');
 200                         entities.Add ("kappa", '\u03BA');
 201                         entities.Add ("lambda", '\u03BB');
 202                         entities.Add ("mu", '\u03BC');
 203                         entities.Add ("nu", '\u03BD');
 204                         entities.Add ("xi", '\u03BE');
 205                         entities.Add ("omicron", '\u03BF');
 206                         entities.Add ("pi", '\u03C0');
 207                         entities.Add ("rho", '\u03C1');
 208                         entities.Add ("sigmaf", '\u03C2');
 209                         entities.Add ("sigma", '\u03C3');
 210                         entities.Add ("tau", '\u03C4');
 211                         entities.Add ("upsilon", '\u03C5');
 212                         entities.Add ("phi", '\u03C6');
 213                         entities.Add ("chi", '\u03C7');
 214                         entities.Add ("psi", '\u03C8');
 215                         entities.Add ("omega", '\u03C9');
 216                         entities.Add ("thetasym", '\u03D1');
 217                         entities.Add ("upsih", '\u03D2');
 218                         entities.Add ("piv", '\u03D6');
 219                         entities.Add ("bull", '\u2022');
 220                         entities.Add ("hellip", '\u2026');
 221                         entities.Add ("prime", '\u2032');
 222                         entities.Add ("Prime", '\u2033');
 223                         entities.Add ("oline", '\u203E');
 224                         entities.Add ("frasl", '\u2044');
 225                         entities.Add ("weierp", '\u2118');
 226                         entities.Add ("image", '\u2111');
 227                         entities.Add ("real", '\u211C');
 228                         entities.Add ("trade", '\u2122');
 229                         entities.Add ("alefsym", '\u2135');
 230                         entities.Add ("larr", '\u2190');
 231                         entities.Add ("uarr", '\u2191');
 232                         entities.Add ("rarr", '\u2192');
 233                         entities.Add ("darr", '\u2193');
 234                         entities.Add ("harr", '\u2194');
 235                         entities.Add ("crarr", '\u21B5');
 236                         entities.Add ("lArr", '\u21D0');
 237                         entities.Add ("uArr", '\u21D1');
 238                         entities.Add ("rArr", '\u21D2');
 239                         entities.Add ("dArr", '\u21D3');
 240                         entities.Add ("hArr", '\u21D4');
 241                         entities.Add ("forall", '\u2200');
 242                         entities.Add ("part", '\u2202');
 243                         entities.Add ("exist", '\u2203');
 244                         entities.Add ("empty", '\u2205');
 245                         entities.Add ("nabla", '\u2207');
 246                         entities.Add ("isin", '\u2208');
 247                         entities.Add ("notin", '\u2209');
 248                         entities.Add ("ni", '\u220B');
 249                         entities.Add ("prod", '\u220F');
 250                         entities.Add ("sum", '\u2211');
 251                         entities.Add ("minus", '\u2212');
 252                         entities.Add ("lowast", '\u2217');
 253                         entities.Add ("radic", '\u221A');
 254                         entities.Add ("prop", '\u221D');
 255                         entities.Add ("infin", '\u221E');
 256                         entities.Add ("ang", '\u2220');
 257                         entities.Add ("and", '\u2227');
 258                         entities.Add ("or", '\u2228');
 259                         entities.Add ("cap", '\u2229');
 260                         entities.Add ("cup", '\u222A');
 261                         entities.Add ("int", '\u222B');
 262                         entities.Add ("there4", '\u2234');
 263                         entities.Add ("sim", '\u223C');
 264                         entities.Add ("cong", '\u2245');
 265                         entities.Add ("asymp", '\u2248');
 266                         entities.Add ("ne", '\u2260');
 267                         entities.Add ("equiv", '\u2261');
 268                         entities.Add ("le", '\u2264');
 269                         entities.Add ("ge", '\u2265');
 270                         entities.Add ("sub", '\u2282');
 271                         entities.Add ("sup", '\u2283');
 272                         entities.Add ("nsub", '\u2284');
 273                         entities.Add ("sube", '\u2286');
 274                         entities.Add ("supe", '\u2287');
 275                         entities.Add ("oplus", '\u2295');
 276                         entities.Add ("otimes", '\u2297');
 277                         entities.Add ("perp", '\u22A5');
 278                         entities.Add ("sdot", '\u22C5');
 279                         entities.Add ("lceil", '\u2308');
 280                         entities.Add ("rceil", '\u2309');
 281                         entities.Add ("lfloor", '\u230A');
 282                         entities.Add ("rfloor", '\u230B');
 283                         entities.Add ("lang", '\u2329');
 284                         entities.Add ("rang", '\u232A');
 285                         entities.Add ("loz", '\u25CA');
 286                         entities.Add ("spades", '\u2660');
 287                         entities.Add ("clubs", '\u2663');
 288                         entities.Add ("hearts", '\u2665');
 289                         entities.Add ("diams", '\u2666');
 290                         entities.Add ("quot", '\u0022');
 291                         entities.Add ("amp", '\u0026');
 292                         entities.Add ("lt", '\u003C');
 293                         entities.Add ("gt", '\u003E');
 294                         entities.Add ("OElig", '\u0152');
 295                         entities.Add ("oelig", '\u0153');
 296                         entities.Add ("Scaron", '\u0160');
 297                         entities.Add ("scaron", '\u0161');
 298                         entities.Add ("Yuml", '\u0178');
 299                         entities.Add ("circ", '\u02C6');
 300                         entities.Add ("tilde", '\u02DC');
 301                         entities.Add ("ensp", '\u2002');
 302                         entities.Add ("emsp", '\u2003');
 303                         entities.Add ("thinsp", '\u2009');
 304                         entities.Add ("zwnj", '\u200C');
 305                         entities.Add ("zwj", '\u200D');
 306                         entities.Add ("lrm", '\u200E');
 307                         entities.Add ("rlm", '\u200F');
 308                         entities.Add ("ndash", '\u2013');
 309                         entities.Add ("mdash", '\u2014');
 310                         entities.Add ("lsquo", '\u2018');
 311                         entities.Add ("rsquo", '\u2019');
 312                         entities.Add ("sbquo", '\u201A');
 313                         entities.Add ("ldquo", '\u201C');
 314                         entities.Add ("rdquo", '\u201D');
 315                         entities.Add ("bdquo", '\u201E');
 316                         entities.Add ("dagger", '\u2020');
 317                         entities.Add ("Dagger", '\u2021');
 318                         entities.Add ("permil", '\u2030');
 319                         entities.Add ("lsaquo", '\u2039');
 320                         entities.Add ("rsaquo", '\u203A');
 321                         entities.Add ("euro", '\u20AC');
 322                 }
 323
 324                 public HttpUtility ()
 325                 {
 326                 }
 327
 328                 #endregion // Constructors
 329
 330                 #region Methods
 331
 332                 public static void HtmlAttributeEncode (string s, TextWriter output)
 333                 {
 334                         output.Write(HtmlAttributeEncode(s));
 335                 }
 336
 337                 public static string HtmlAttributeEncode (string s)
 338                 {
 339                         if (null == s)
 340                                 return null;
 341
 342                         bool needEncode = false;
 343                         for (int i = 0; i < s.Length; i++) {
 344                                 if (s [i] == '&' || s [i] == '"' || s [i] == '<') {
 345                                         needEncode = true;
 346                                         break;
 347                                 }
 348                         }
 349
 350                         if (!needEncode)
 351                                 return s;
 352
 353                         StringBuilder output = new StringBuilder ();
 354                         int len = s.Length;
 355                         for (int i = 0; i < len; i++)
 356                                 switch (s [i]) {
 357                                 case '&' :
 358                                         output.Append ("&amp;");
 359                                         break;
 360                                 case '"' :
 361                                         output.Append ("&quot;");
 362                                         break;
 363                                 case '<':
 364                                         output.Append ("&lt;");
 365                                         break;
 366                                 default:
 367                                         output.Append (s [i]);
 368                                         break;
 369                                 }
 370
 371                         return output.ToString();
 372                 }
 373
 374                 public static string UrlDecode (string str)
 375                 {
 376                         return UrlDecode(str, Encoding.UTF8);
 377                 }
 378
 379                 private static char [] GetChars (MemoryStream b, Encoding e)
 380                 {
 381                         return e.GetChars (b.GetBuffer (), 0, (int) b.Length);
 382                 }
 383
 384                 public static string UrlDecode (string s, Encoding e)
 385                 {
 386                         if (null == s)
 387                                 return null;
 388
 389                         if (s.IndexOf ('%') == -1 && s.IndexOf ('+') == -1)
 390                                 return s;
 391
 392                         if (e == null)
 393                                 e = Encoding.UTF8;
 394
 395                         StringBuilder output = new StringBuilder ();
 396                         long len = s.Length;
 397                         MemoryStream bytes = new MemoryStream ();
 398                         int xchar;
 399
 400                         for (int i = 0; i < len; i++) {
 401                                 if (s [i] == '%' && i + 2 < len && s [i + 1] != '%') {
 402                                         if (s [i + 1] == 'u' && i + 5 < len) {
 403                                                 if (bytes.Length > 0) {
 404                                                         output.Append (GetChars (bytes, e));
 405                                                         bytes.SetLength (0);
 406                                                 }
 407
 408                                                 xchar = GetChar (s, i + 2, 4);
 409                                                 if (xchar != -1) {
 410                                                         output.Append ((char) xchar);
 411                                                         i += 5;
 412                                                 } else {
 413                                                         output.Append ('%');
 414                                                 }
 415                                         } else if ((xchar = GetChar (s, i + 1, 2)) != -1) {
 416                                                 bytes.WriteByte ((byte) xchar);
 417                                                 i += 2;
 418                                         } else {
 419                                                 output.Append ('%');
 420                                         }
 421                                         continue;
 422                                 }
 423
 424                                 if (bytes.Length > 0) {
 425                                         output.Append (GetChars (bytes, e));
 426                                         bytes.SetLength (0);
 427                                 }
 428
 429                                 if (s [i] == '+') {
 430                                         output.Append (' ');
 431                                 } else {
 432                                         output.Append (s [i]);
 433                                 }
 434                         }
 435
 436                         if (bytes.Length > 0) {
 437                                 output.Append (GetChars (bytes, e));
 438                         }
 439
 440                         bytes = null;
 441                         return output.ToString ();
 442                 }
 443
 444                 public static string UrlDecode (byte [] bytes, Encoding e)
 445                 {
 446                         if (bytes == null)
 447                                 return null;
 448
 449                         return UrlDecode (bytes, 0, bytes.Length, e);
 450                 }
 451
 452                 private static int GetInt (byte b)
 453                 {
 454                         char c = (char) b;
 455                         if (c >= '0' && c <= '9')
 456                                 return c - '0';
 457
 458                         if (c >= 'a' && c <= 'f')
 459                                 return c - 'a' + 10;
 460
 461                         if (c >= 'A' && c <= 'F')
 462                                 return c - 'A' + 10;
 463
 464                         return -1;
 465                 }
 466
 467                 private static int GetChar (byte [] bytes, int offset, int length)
 468                 {
 469                         int value = 0;
 470                         int end = length + offset;
 471                         for (int i = offset; i < end; i++) {
 472                                 int current = GetInt (bytes [i]);
 473                                 if (current == -1)
 474                                         return -1;
 475                                 value = (value << 4) + current;
 476                         }
 477
 478                         return value;
 479                 }
 480
 481                 private static int GetChar (string str, int offset, int length)
 482                 {
 483                         int val = 0;
 484                         int end = length + offset;
 485                         for (int i = offset; i < end; i++) {
 486                                 char c = str [i];
 487                                 if (c > 127)
 488                                         return -1;
 489
 490                                 int current = GetInt ((byte) c);
 491                                 if (current == -1)
 492                                         return -1;
 493                                 val = (val << 4) + current;
 494                         }
 495
 496                         return val;
 497                 }
 498
 499                 public static string UrlDecode (byte [] bytes, int offset, int count, Encoding e)
 500                 {
 501                         if (bytes == null)
 502                                 return null;
 503                         if (count == 0)
 504                                 return String.Empty;
 505
 506                         if (bytes == null)
 507                                 throw new ArgumentNullException ("bytes");
 508
 509                         if (offset < 0 || offset > bytes.Length)
 510                                 throw new ArgumentOutOfRangeException ("offset");
 511
 512                         if (count < 0 || offset + count > bytes.Length)
 513                                 throw new ArgumentOutOfRangeException ("count");
 514
 515                         StringBuilder output = new StringBuilder ();
 516                         MemoryStream acc = new MemoryStream ();
 517
 518                         int end = count + offset;
 519                         int xchar;
 520                         for (int i = offset; i < end; i++) {
 521                                 if (bytes [i] == '%' && i + 2 < count && bytes [i + 1] != '%') {
 522                                         if (bytes [i + 1] == (byte) 'u' && i + 5 < end) {
 523                                                 if (acc.Length > 0) {
 524                                                         output.Append (GetChars (acc, e));
 525                                                         acc.SetLength (0);
 526                                                 }
 527                                                 xchar = GetChar (bytes, i + 2, 4);
 528                                                 if (xchar != -1) {
 529                                                         output.Append ((char) xchar);
 530                                                         i += 5;
 531                                                         continue;
 532                                                 }
 533                                         } else if ((xchar = GetChar (bytes, i + 1, 2)) != -1) {
 534                                                 acc.WriteByte ((byte) xchar);
 535                                                 i += 2;
 536                                                 continue;
 537                                         }
 538                                 }
 539
 540                                 if (acc.Length > 0) {
 541                                         output.Append (GetChars (acc, e));
 542                                         acc.SetLength (0);
 543                                 }
 544
 545                                 if (bytes [i] == '+') {
 546                                         output.Append (' ');
 547                                 } else {
 548                                         output.Append ((char) bytes [i]);
 549                                 }
 550                         }
 551
 552                         if (acc.Length > 0) {
 553                                 output.Append (GetChars (acc, e));
 554                         }
 555
 556                         acc = null;
 557                         return output.ToString ();
 558                 }
 559
 560                 public static byte [] UrlDecodeToBytes (byte [] bytes)
 561                 {
 562                         if (bytes == null)
 563                                 return null;
 564
 565                         return UrlDecodeToBytes (bytes, 0, bytes.Length);
 566                 }
 567
 568                 public static byte [] UrlDecodeToBytes (string str)
 569                 {
 570                         return UrlDecodeToBytes (str, Encoding.UTF8);
 571                 }
 572
 573                 public static byte [] UrlDecodeToBytes (string str, Encoding e)
 574                 {
 575                         if (str == null)
 576                                 return null;
 577
 578                         if (e == null)
 579                                 throw new ArgumentNullException ("e");
 580
 581                         return UrlDecodeToBytes (e.GetBytes (str));
 582                 }
 583
 584                 public static byte [] UrlDecodeToBytes (byte [] bytes, int offset, int count)
 585                 {
 586                         if (bytes == null)
 587                                 return null;
 588                         if (count == 0)
 589                                 return new byte [0];
 590
 591                         int len = bytes.Length;
 592                         if (offset < 0 || offset >= len)
 593                                 throw new ArgumentOutOfRangeException("offset");
 594
 595                         if (count < 0 || offset > len - count)
 596                                 throw new ArgumentOutOfRangeException("count");
 597
 598                         MemoryStream result = new MemoryStream ();
 599                         int end = offset + count;
 600                         for (int i = offset; i < end; i++){
 601                                 char c = (char) bytes [i];
 602                                 if (c == '+') {
 603                                         c = ' ';
 604                                 } else if (c == '%' && i < end - 2) {
 605                                         int xchar = GetChar (bytes, i + 1, 2);
 606                                         if (xchar != -1) {
 607                                                 c = (char) xchar;
 608                                                 i += 2;
 609                                         }
 610                                 }
 611                                 result.WriteByte ((byte) c);
 612                         }
 613
 614                         return result.ToArray ();
 615                 }
 616
 617                 public static string UrlEncode(string str)
 618                 {
 619                         return UrlEncode(str, Encoding.UTF8);
 620                 }
 621
 622                 public static string UrlEncode (string s, Encoding Enc)
 623                 {
 624                         if (s == null)
 625                                 return null;
 626
 627                         if (s == "")
 628                                 return "";
 629
 630                         bool needEncode = false;
 631                         int len = s.Length;
 632                         for (int i = 0; i < len; i++) {
 633                                 char c = s [i];
 634                                 if ((c < '0') || (c < 'A' && c > '9') || (c > 'Z' && c < 'a') || (c > 'z')) {
 635                                         if (NotEncoded (c))
 636                                                 continue;
 637
 638                                         needEncode = true;
 639                                         break;
 640                                 }
 641                         }
 642
 643                         if (!needEncode)
 644                                 return s;
 645
 646                         // avoided GetByteCount call
 647                         byte [] bytes = new byte[Enc.GetMaxByteCount(s.Length)];
 648                         int realLen = Enc.GetBytes (s, 0, s.Length, bytes, 0);
 649                         return Encoding.ASCII.GetString (UrlEncodeToBytes (bytes, 0, realLen));
 650                 }
 651
 652                 public static string UrlEncode (byte [] bytes)
 653                 {
 654                         if (bytes == null)
 655                                 return null;
 656
 657                         if (bytes.Length == 0)
 658                                 return "";
 659
 660                         return Encoding.ASCII.GetString (UrlEncodeToBytes (bytes, 0, bytes.Length));
 661                 }
 662
 663                 public static string UrlEncode (byte [] bytes, int offset, int count)
 664                 {
 665                         if (bytes == null)
 666                                 return null;
 667
 668                         if (bytes.Length == 0)
 669                                 return "";
 670
 671                         return Encoding.ASCII.GetString (UrlEncodeToBytes (bytes, offset, count));
 672                 }
 673
 674                 public static byte [] UrlEncodeToBytes (string str)
 675                 {
 676                         return UrlEncodeToBytes (str, Encoding.UTF8);
 677                 }
 678
 679                 public static byte [] UrlEncodeToBytes (string str, Encoding e)
 680                 {
 681                         if (str == null)
 682                                 return null;
 683
 684                         if (str == "")
 685                                 return new byte [0];
 686
 687                         byte [] bytes = e.GetBytes (str);
 688                         return UrlEncodeToBytes (bytes, 0, bytes.Length);
 689                 }
 690
 691                 public static byte [] UrlEncodeToBytes (byte [] bytes)
 692                 {
 693                         if (bytes == null)
 694                                 return null;
 695
 696                         if (bytes.Length == 0)
 697                                 return new byte [0];
 698
 699                         return UrlEncodeToBytes (bytes, 0, bytes.Length);
 700                 }
 701
 702                 static char [] hexChars = "0123456789abcdef".ToCharArray ();
 703
 704                 static bool NotEncoded (char c)
 705                 {
 706                         return (c == '!' || c == '\'' || c == '(' || c == ')' || c == '*' || c == '-' || c == '.' || c == '_');
 707                 }
 708
 709                 static void UrlEncodeChar (char c, Stream result, bool isUnicode) {
 710                         if (c > 255) {
 711                                 //FIXME: what happens when there is an internal error?
 712                                 //if (!isUnicode)
 713                                 //      throw new ArgumentOutOfRangeException ("c", c, "c must be less than 256");
 714                                 int idx;
 715                                 int i = (int) c;
 716
 717                                 result.WriteByte ((byte)'%');
 718                                 result.WriteByte ((byte)'u');
 719                                 idx = i >> 12;
 720                                 result.WriteByte ((byte)hexChars [idx]);
 721                                 idx = (i >> 8) & 0x0F;
 722                                 result.WriteByte ((byte)hexChars [idx]);
 723                                 idx = (i >> 4) & 0x0F;
 724                                 result.WriteByte ((byte)hexChars [idx]);
 725                                 idx = i & 0x0F;
 726                                 result.WriteByte ((byte)hexChars [idx]);
 727                                 return;
 728                         }
 729
 730                         if (c > ' ' && NotEncoded (c)) {
 731                                 result.WriteByte ((byte)c);
 732                                 return;
 733                         }
 734                         if (c==' ') {
 735                                 result.WriteByte ((byte)'+');
 736                                 return;
 737                         }
 738                         if (    (c < '0') ||
 739                                 (c < 'A' && c > '9') ||
 740                                 (c > 'Z' && c < 'a') ||
 741                                 (c > 'z')) {
 742                                 if (isUnicode && c > 127) {
 743                                         result.WriteByte ((byte)'%');
 744                                         result.WriteByte ((byte)'u');
 745                                         result.WriteByte ((byte)'0');
 746                                         result.WriteByte ((byte)'0');
 747                                 }
 748                                 else
 749                                         result.WriteByte ((byte)'%');
 750
 751                                 int idx = ((int) c) >> 4;
 752                                 result.WriteByte ((byte)hexChars [idx]);
 753                                 idx = ((int) c) & 0x0F;
 754                                 result.WriteByte ((byte)hexChars [idx]);
 755                         }
 756                         else
 757                                 result.WriteByte ((byte)c);
 758                 }
 759
 760                 public static byte [] UrlEncodeToBytes (byte [] bytes, int offset, int count)
 761                 {
 762                         if (bytes == null)
 763                                 return null;
 764
 765                         int len = bytes.Length;
 766                         if (len == 0)
 767                                 return new byte [0];
 768
 769                         if (offset < 0 || offset >= len)
 770                                 throw new ArgumentOutOfRangeException("offset");
 771
 772                         if (count < 0 || count > len - offset)
 773                                 throw new ArgumentOutOfRangeException("count");
 774
 775                         MemoryStream result = new MemoryStream (count);
 776                         int end = offset + count;
 777                         for (int i = offset; i < end; i++)
 778                                 UrlEncodeChar ((char)bytes [i], result, false);
 779
 780                         return result.ToArray();
 781                 }
 782
 783                 public static string UrlEncodeUnicode (string str)
 784                 {
 785                         if (str == null)
 786                                 return null;
 787
 788                         return Encoding.ASCII.GetString (UrlEncodeUnicodeToBytes (str));
 789                 }
 790
 791                 public static byte [] UrlEncodeUnicodeToBytes (string str)
 792                 {
 793                         if (str == null)
 794                                 return null;
 795
 796                         if (str == "")
 797                                 return new byte [0];
 798
 799                         MemoryStream result = new MemoryStream (str.Length);
 800                         foreach (char c in str){
 801                                 UrlEncodeChar (c, result, true);
 802                         }
 803                         return result.ToArray ();
 804                 }
 805
 806                 /// <summary>
 807                 /// Decodes an HTML-encoded string and returns the decoded string.
 808                 /// </summary>
 809                 /// <param name="s">The HTML string to decode. </param>
 810                 /// <returns>The decoded text.</returns>
 811                 public static string HtmlDecode (string s)
 812                 {
 813                         if (s == null)
 814                                 throw new ArgumentNullException ("s");
 815
 816                         if (s.IndexOf ('&') == -1)
 817                                 return s;
 818
 819                         StringBuilder entity = new StringBuilder ();
 820                         StringBuilder output = new StringBuilder ();
 821                         int len = s.Length;
 822                         // 0 -> nothing,
 823                         // 1 -> right after '&'
 824                         // 2 -> between '&' and ';' but no '#'
 825                         // 3 -> '#' found after '&' and getting numbers
 826                         int state = 0;
 827                         int number = 0;
 828                         bool have_trailing_digits = false;
 829
 830                         for (int i = 0; i < len; i++) {
 831                                 char c = s [i];
 832                                 if (state == 0) {
 833                                         if (c == '&') {
 834                                                 entity.Append (c);
 835                                                 state = 1;
 836                                         } else {
 837                                                 output.Append (c);
 838                                         }
 839                                         continue;
 840                                 }
 841
 842                                 if (c == '&') {
 843                                         state = 1;
 844                                         if (have_trailing_digits) {
 845                                                 entity.Append (number.ToString (CultureInfo.InvariantCulture));
 846                                                 have_trailing_digits = false;
 847                                         }
 848
 849                                         output.Append (entity.ToString ());
 850                                         entity.Length = 0;
 851                                         entity.Append ('&');
 852                                         continue;
 853                                 }
 854
 855                                 if (state == 1) {
 856                                         if (c == ';') {
 857                                                 state = 0;
 858                                                 output.Append (entity.ToString ());
 859                                                 output.Append (c);
 860                                                 entity.Length = 0;
 861                                         } else {
 862                                                 number = 0;
 863                                                 if (c != '#') {
 864                                                         state = 2;
 865                                                 } else {
 866                                                         state = 3;
 867                                                 }
 868                                                 entity.Append (c);
 869                                         }
 870                                 } else if (state == 2) {
 871                                         entity.Append (c);
 872                                         if (c == ';') {
 873                                                 string key = entity.ToString ();
 874                                                 if (key.Length > 1 && Entities.ContainsKey (key.Substring (1, key.Length - 2)))
 875                                                         key = Entities [key.Substring (1, key.Length - 2)].ToString ();
 876
 877                                                 output.Append (key);
 878                                                 state = 0;
 879                                                 entity.Length = 0;
 880                                         }
 881                                 } else if (state == 3) {
 882                                         if (c == ';') {
 883                                                 if (number > 65535) {
 884                                                         output.Append ("&#");
 885                                                         output.Append (number.ToString (CultureInfo.InvariantCulture));
 886                                                         output.Append (";");
 887                                                 } else {
 888                                                         output.Append ((char) number);
 889                                                 }
 890                                                 state = 0;
 891                                                 entity.Length = 0;
 892                                                 have_trailing_digits = false;
 893                                         } else if (Char.IsDigit (c)) {
 894                                                 number = number * 10 + ((int) c - '0');
 895                                                 have_trailing_digits = true;
 896                                         } else {
 897                                                 state = 2;
 898                                                 if (have_trailing_digits) {
 899                                                         entity.Append (number.ToString (CultureInfo.InvariantCulture));
 900                                                         have_trailing_digits = false;
 901                                                 }
 902                                                 entity.Append (c);
 903                                         }
 904                                 }
 905                         }
 906
 907                         if (entity.Length > 0) {
 908                                 output.Append (entity.ToString ());
 909                         } else if (have_trailing_digits) {
 910                                 output.Append (number.ToString (CultureInfo.InvariantCulture));
 911                         }
 912                         return output.ToString ();
 913                 }
 914
 915                 /// <summary>
 916                 /// Decodes an HTML-encoded string and sends the resulting output to a TextWriter output stream.
 917                 /// </summary>
 918                 /// <param name="s">The HTML string to decode</param>
 919                 /// <param name="output">The TextWriter output stream containing the decoded string. </param>
 920                 public static void HtmlDecode(string s, TextWriter output)
 921                 {
 922                         if (s != null)
 923                                 output.Write (HtmlDecode (s));
 924                 }
 925
 926                 /// <summary>
 927                 /// HTML-encodes a string and returns the encoded string.
 928                 /// </summary>
 929                 /// <param name="s">The text string to encode. </param>
 930                 /// <returns>The HTML-encoded text.</returns>
 931                 public static string HtmlEncode (string s)
 932                 {
 933                         if (s == null)
 934                                 return null;
 935
 936                         bool needEncode = false;
 937                         for (int i = 0; i < s.Length; i++) {
 938                                 char c = s [i];
 939                                 if (c == '&' || c == '"' || c == '<' || c == '>' || c > 159) {
 940                                         needEncode = true;
 941                                         break;
 942                                 }
 943                         }
 944
 945                         if (!needEncode)
 946                                 return s;
 947
 948                         StringBuilder output = new StringBuilder ();
 949
 950                         int len = s.Length;
 951                         for (int i = 0; i < len; i++)
 952                                 switch (s [i]) {
 953                                 case '&' :
 954                                         output.Append ("&amp;");
 955                                         break;
 956                                 case '>' :
 957                                         output.Append ("&gt;");
 958                                         break;
 959                                 case '<' :
 960                                         output.Append ("&lt;");
 961                                         break;
 962                                 case '"' :
 963                                         output.Append ("&quot;");
 964                                         break;
 965                                 default:
 966                                         // MS starts encoding with &# from 160 and stops at 255.
 967                                         // We don't do that. One reason is the 65308/65310 unicode
 968                                         // characters that look like '<' and '>'.
 969 #if TARGET_JVM
 970                                         if (s [i] > 159 && s [i] < 256) {
 971 #else
 972                                         if (s [i] > 159) {
 973 #endif
 974                                                 output.Append ("&#");
 975                                                 output.Append (((int) s [i]).ToString (CultureInfo.InvariantCulture));
 976                                                 output.Append (";");
 977                                         } else {
 978                                                 output.Append (s [i]);
 979                                         }
 980                                         break;
 981                                 }
 982                         return output.ToString ();
 983                 }
 984
 985                 /// <summary>
 986                 /// HTML-encodes a string and sends the resulting output to a TextWriter output stream.
 987                 /// </summary>
 988                 /// <param name="s">The string to encode. </param>
 989                 /// <param name="output">The TextWriter output stream containing the encoded string. </param>
 990                 public static void HtmlEncode(string s, TextWriter output)
 991                 {
 992                         if (s != null)
 993                                 output.Write (HtmlEncode (s));
 994                 }
 995
 996 #if NET_1_1
 997                 public static string UrlPathEncode (string s)
 998                 {
 999                         if (s == null || s.Length == 0)
1000                                 return s;
1001
1002                         MemoryStream result = new MemoryStream ();
1003                         int length = s.Length;
1004             for (int i = 0; i < length; i++) {
1005                                 UrlPathEncodeChar (s [i], result);
1006                         }
1007                         return Encoding.ASCII.GetString (result.ToArray ());
1008                 }
1009
1010                 static void UrlPathEncodeChar (char c, Stream result) {
1011 #if NET_2_0
1012                         if (c < 33 || c > 126) {
1013 #else
1014                         if (c > 127) {
1015 #endif
1016                                 byte [] bIn = Encoding.UTF8.GetBytes (c.ToString ());
1017                                 for (int i = 0; i < bIn.Length; i++) {
1018                                         result.WriteByte ((byte) '%');
1019                                         int idx = ((int) bIn [i]) >> 4;
1020                                         result.WriteByte ((byte) hexChars [idx]);
1021                                         idx = ((int) bIn [i]) & 0x0F;
1022                                         result.WriteByte ((byte) hexChars [idx]);
1023                                 }
1024                         }
1025                         else if (c == ' ') {
1026                                 result.WriteByte ((byte) '%');
1027                                 result.WriteByte ((byte) '2');
1028                                 result.WriteByte ((byte) '0');
1029                         }
1030                         else
1031                                 result.WriteByte ((byte) c);
1032                 }
1033 #endif
1034
1035 #if NET_2_0
1036                 public static NameValueCollection ParseQueryString (string query)
1037                 {
1038                         return ParseQueryString (query, Encoding.UTF8);
1039                 }
1040
1041                 public static NameValueCollection ParseQueryString (string query, Encoding encoding)
1042                 {
1043                         if (query == null)
1044                                 throw new ArgumentNullException ("query");
1045                         if (encoding == null)
1046                                 throw new ArgumentNullException ("encoding");
1047                         if (query.Length == 0 || (query.Length == 1 && query[0] == '?'))
1048                                 return new NameValueCollection ();
1049                         if (query[0] == '?')
1050                                 query = query.Substring (1);
1051
1052                         NameValueCollection result = new NameValueCollection ();
1053                         ParseQueryString (query, encoding, result);
1054                         return result;
1055                 }
1056 #endif
1057
1058                 internal static void ParseQueryString (string query, Encoding encoding, NameValueCollection result)
1059                 {
1060                         if (query.Length == 0)
1061                                 return;
1062
1063                         int namePos = 0;
1064                         bool first = true;
1065                         while (namePos <= query.Length) {
1066                                 int valuePos = -1, valueEnd = -1;
1067                                 for (int q = namePos; q < query.Length; q++) {
1068                                         if (valuePos == -1 && query[q] == '=') {
1069                                                 valuePos = q + 1;
1070                                         } else if (query[q] == '&') {
1071                                                 valueEnd = q;
1072                                                 break;
1073                                         }
1074                                 }
1075
1076                                 if (first) {
1077                                         first = false;
1078                                         if (query [namePos] == '?')
1079                                                 namePos++;
1080                                 }
1081
1082                                 string name, value;
1083                                 if (valuePos == -1) {
1084                                         name = null;
1085                                         valuePos = namePos;
1086                                 } else {
1087                                         name = UrlDecode (query.Substring (namePos, valuePos - namePos - 1), encoding);
1088                                 }
1089                                 if (valueEnd < 0) {
1090                                         namePos = -1;
1091                                         valueEnd = query.Length;
1092                                 } else {
1093                                         namePos = valueEnd + 1;
1094                                 }
1095                                 value = UrlDecode (query.Substring (valuePos, valueEnd - valuePos), encoding);
1096
1097                                 result.Add (name, value);
1098                                 if (namePos == -1)
1099                                         break;
1100                         }
1101                 }
1102                 #endregion // Methods
1103         }
1104 }
1105