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) 2005-2010 Novell, Inc (http://www.novell.com)
  11 //
  12 // Permission is hereby granted, free of charge, to any person obtaining
  13 // a copy of this software and associated documentation files (the
  14 // "Software"), to deal in the Software without restriction, including
  15 // without limitation the rights to use, copy, modify, merge, publish,
  16 // distribute, sublicense, and/or sell copies of the Software, and to
  17 // permit persons to whom the Software is furnished to do so, subject to
  18 // the following conditions:
  19 //
  20 // The above copyright notice and this permission notice shall be
  21 // included in all copies or substantial portions of the Software.
  22 //
  23 // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
  24 // EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  25 // MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
  26 // NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
  27 // LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
  28 // OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
  29 // WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  30 //
  31
  32 using System.Collections;
  33 using System.Collections.Generic;
  34 using System.Collections.Specialized;
  35 using System.Globalization;
  36 using System.IO;
  37 using System.Security.Permissions;
  38 using System.Text;
  39 using System.Web.Util;
  40
  41 namespace System.Web {
  42
  43 #if !MOBILE
  44         // CAS - no InheritanceDemand here as the class is sealed
  45         [AspNetHostingPermission (SecurityAction.LinkDemand, Level = AspNetHostingPermissionLevel.Minimal)]
  46 #endif
  47         public sealed class HttpUtility
  48         {
  49                 sealed class HttpQSCollection : NameValueCollection
  50                 {
  51                         public override string ToString ()
  52                         {
  53                                 int count = Count;
  54                                 if (count == 0)
  55                                         return "";
  56                                 StringBuilder sb = new StringBuilder ();
  57                                 string [] keys = AllKeys;
  58                                 for (int i = 0; i < count; i++) {
  59                                         sb.AppendFormat ("{0}={1}&", keys [i], this [keys [i]]);
  60                                 }
  61                                 if (sb.Length > 0)
  62                                         sb.Length--;
  63                                 return sb.ToString ();
  64                         }
  65                 }
  66
  67                 #region Constructors
  68
  69                 public HttpUtility ()
  70                 {
  71                 }
  72
  73                 #endregion // Constructors
  74
  75                 #region Methods
  76
  77                 public static void HtmlAttributeEncode (string s, TextWriter output)
  78                 {
  79                         if (output == null) {
  80 #if NET_4_0
  81                                 throw new ArgumentNullException ("output");
  82 #else
  83                                 throw new NullReferenceException (".NET emulation");
  84 #endif
  85                         }
  86 #if NET_4_0
  87                         HttpEncoder.Current.HtmlAttributeEncode (s, output);
  88 #else
  89                         output.Write (HttpEncoder.HtmlAttributeEncode (s));
  90 #endif
  91                 }
  92
  93                 public static string HtmlAttributeEncode (string s)
  94                 {
  95 #if NET_4_0
  96                         if (s == null)
  97                                 return null;
  98
  99                         using (var sw = new StringWriter ()) {
 100                                 HttpEncoder.Current.HtmlAttributeEncode (s, sw);
 101                                 return sw.ToString ();
 102                         }
 103 #else
 104                         return HttpEncoder.HtmlAttributeEncode (s);
 105 #endif
 106                 }
 107
 108                 public static string UrlDecode (string str)
 109                 {
 110                         return UrlDecode(str, Encoding.UTF8);
 111                 }
 112
 113                 static char [] GetChars (MemoryStream b, Encoding e)
 114                 {
 115                         return e.GetChars (b.GetBuffer (), 0, (int) b.Length);
 116                 }
 117
 118                 static void WriteCharBytes (IList buf, char ch, Encoding e)
 119                 {
 120                         if (ch > 255) {
 121                                 foreach (byte b in e.GetBytes (new char[] { ch }))
 122                                         buf.Add (b);
 123                         } else
 124                                 buf.Add ((byte)ch);
 125                 }
 126
 127                 public static string UrlDecode (string s, Encoding e)
 128                 {
 129                         if (null == s)
 130                                 return null;
 131
 132                         if (s.IndexOf ('%') == -1 && s.IndexOf ('+') == -1)
 133                                 return s;
 134
 135                         if (e == null)
 136                                 e = Encoding.UTF8;
 137
 138                         long len = s.Length;
 139                         var bytes = new List <byte> ();
 140                         int xchar;
 141                         char ch;
 142
 143                         for (int i = 0; i < len; i++) {
 144                                 ch = s [i];
 145                                 if (ch == '%' && i + 2 < len && s [i + 1] != '%') {
 146                                         if (s [i + 1] == 'u' && i + 5 < len) {
 147                                                 // unicode hex sequence
 148                                                 xchar = GetChar (s, i + 2, 4);
 149                                                 if (xchar != -1) {
 150                                                         WriteCharBytes (bytes, (char)xchar, e);
 151                                                         i += 5;
 152                                                 } else
 153                                                         WriteCharBytes (bytes, '%', e);
 154                                         } else if ((xchar = GetChar (s, i + 1, 2)) != -1) {
 155                                                 WriteCharBytes (bytes, (char)xchar, e);
 156                                                 i += 2;
 157                                         } else {
 158                                                 WriteCharBytes (bytes, '%', e);
 159                                         }
 160                                         continue;
 161                                 }
 162
 163                                 if (ch == '+')
 164                                         WriteCharBytes (bytes, ' ', e);
 165                                 else
 166                                         WriteCharBytes (bytes, ch, e);
 167                         }
 168
 169                         byte[] buf = bytes.ToArray ();
 170                         bytes = null;
 171                         return e.GetString (buf);
 172
 173                 }
 174
 175                 public static string UrlDecode (byte [] bytes, Encoding e)
 176                 {
 177                         if (bytes == null)
 178                                 return null;
 179
 180                         return UrlDecode (bytes, 0, bytes.Length, e);
 181                 }
 182
 183                 static int GetInt (byte b)
 184                 {
 185                         char c = (char) b;
 186                         if (c >= '0' && c <= '9')
 187                                 return c - '0';
 188
 189                         if (c >= 'a' && c <= 'f')
 190                                 return c - 'a' + 10;
 191
 192                         if (c >= 'A' && c <= 'F')
 193                                 return c - 'A' + 10;
 194
 195                         return -1;
 196                 }
 197
 198                 static int GetChar (byte [] bytes, int offset, int length)
 199                 {
 200                         int value = 0;
 201                         int end = length + offset;
 202                         for (int i = offset; i < end; i++) {
 203                                 int current = GetInt (bytes [i]);
 204                                 if (current == -1)
 205                                         return -1;
 206                                 value = (value << 4) + current;
 207                         }
 208
 209                         return value;
 210                 }
 211
 212                 static int GetChar (string str, int offset, int length)
 213                 {
 214                         int val = 0;
 215                         int end = length + offset;
 216                         for (int i = offset; i < end; i++) {
 217                                 char c = str [i];
 218                                 if (c > 127)
 219                                         return -1;
 220
 221                                 int current = GetInt ((byte) c);
 222                                 if (current == -1)
 223                                         return -1;
 224                                 val = (val << 4) + current;
 225                         }
 226
 227                         return val;
 228                 }
 229
 230                 public static string UrlDecode (byte [] bytes, int offset, int count, Encoding e)
 231                 {
 232                         if (bytes == null)
 233                                 return null;
 234                         if (count == 0)
 235                                 return String.Empty;
 236
 237                         if (bytes == null)
 238                                 throw new ArgumentNullException ("bytes");
 239
 240                         if (offset < 0 || offset > bytes.Length)
 241                                 throw new ArgumentOutOfRangeException ("offset");
 242
 243                         if (count < 0 || offset + count > bytes.Length)
 244                                 throw new ArgumentOutOfRangeException ("count");
 245
 246                         StringBuilder output = new StringBuilder ();
 247                         MemoryStream acc = new MemoryStream ();
 248
 249                         int end = count + offset;
 250                         int xchar;
 251                         for (int i = offset; i < end; i++) {
 252                                 if (bytes [i] == '%' && i + 2 < count && bytes [i + 1] != '%') {
 253                                         if (bytes [i + 1] == (byte) 'u' && i + 5 < end) {
 254                                                 if (acc.Length > 0) {
 255                                                         output.Append (GetChars (acc, e));
 256                                                         acc.SetLength (0);
 257                                                 }
 258                                                 xchar = GetChar (bytes, i + 2, 4);
 259                                                 if (xchar != -1) {
 260                                                         output.Append ((char) xchar);
 261                                                         i += 5;
 262                                                         continue;
 263                                                 }
 264                                         } else if ((xchar = GetChar (bytes, i + 1, 2)) != -1) {
 265                                                 acc.WriteByte ((byte) xchar);
 266                                                 i += 2;
 267                                                 continue;
 268                                         }
 269                                 }
 270
 271                                 if (acc.Length > 0) {
 272                                         output.Append (GetChars (acc, e));
 273                                         acc.SetLength (0);
 274                                 }
 275
 276                                 if (bytes [i] == '+') {
 277                                         output.Append (' ');
 278                                 } else {
 279                                         output.Append ((char) bytes [i]);
 280                                 }
 281                         }
 282
 283                         if (acc.Length > 0) {
 284                                 output.Append (GetChars (acc, e));
 285                         }
 286
 287                         acc = null;
 288                         return output.ToString ();
 289                 }
 290
 291                 public static byte [] UrlDecodeToBytes (byte [] bytes)
 292                 {
 293                         if (bytes == null)
 294                                 return null;
 295
 296                         return UrlDecodeToBytes (bytes, 0, bytes.Length);
 297                 }
 298
 299                 public static byte [] UrlDecodeToBytes (string str)
 300                 {
 301                         return UrlDecodeToBytes (str, Encoding.UTF8);
 302                 }
 303
 304                 public static byte [] UrlDecodeToBytes (string str, Encoding e)
 305                 {
 306                         if (str == null)
 307                                 return null;
 308
 309                         if (e == null)
 310                                 throw new ArgumentNullException ("e");
 311
 312                         return UrlDecodeToBytes (e.GetBytes (str));
 313                 }
 314
 315                 public static byte [] UrlDecodeToBytes (byte [] bytes, int offset, int count)
 316                 {
 317                         if (bytes == null)
 318                                 return null;
 319                         if (count == 0)
 320                                 return new byte [0];
 321
 322                         int len = bytes.Length;
 323                         if (offset < 0 || offset >= len)
 324                                 throw new ArgumentOutOfRangeException("offset");
 325
 326                         if (count < 0 || offset > len - count)
 327                                 throw new ArgumentOutOfRangeException("count");
 328
 329                         MemoryStream result = new MemoryStream ();
 330                         int end = offset + count;
 331                         for (int i = offset; i < end; i++){
 332                                 char c = (char) bytes [i];
 333                                 if (c == '+') {
 334                                         c = ' ';
 335                                 } else if (c == '%' && i < end - 2) {
 336                                         int xchar = GetChar (bytes, i + 1, 2);
 337                                         if (xchar != -1) {
 338                                                 c = (char) xchar;
 339                                                 i += 2;
 340                                         }
 341                                 }
 342                                 result.WriteByte ((byte) c);
 343                         }
 344
 345                         return result.ToArray ();
 346                 }
 347
 348                 public static string UrlEncode(string str)
 349                 {
 350                         return UrlEncode(str, Encoding.UTF8);
 351                 }
 352
 353                 public static string UrlEncode (string s, Encoding Enc)
 354                 {
 355                         if (s == null)
 356                                 return null;
 357
 358                         if (s == String.Empty)
 359                                 return String.Empty;
 360
 361                         bool needEncode = false;
 362                         int len = s.Length;
 363                         for (int i = 0; i < len; i++) {
 364                                 char c = s [i];
 365                                 if ((c < '0') || (c < 'A' && c > '9') || (c > 'Z' && c < 'a') || (c > 'z')) {
 366                                         if (HttpEncoder.NotEncoded (c))
 367                                                 continue;
 368
 369                                         needEncode = true;
 370                                         break;
 371                                 }
 372                         }
 373
 374                         if (!needEncode)
 375                                 return s;
 376
 377                         // avoided GetByteCount call
 378                         byte [] bytes = new byte[Enc.GetMaxByteCount(s.Length)];
 379                         int realLen = Enc.GetBytes (s, 0, s.Length, bytes, 0);
 380                         return Encoding.ASCII.GetString (UrlEncodeToBytes (bytes, 0, realLen));
 381                 }
 382
 383                 public static string UrlEncode (byte [] bytes)
 384                 {
 385                         if (bytes == null)
 386                                 return null;
 387
 388                         if (bytes.Length == 0)
 389                                 return String.Empty;
 390
 391                         return Encoding.ASCII.GetString (UrlEncodeToBytes (bytes, 0, bytes.Length));
 392                 }
 393
 394                 public static string UrlEncode (byte [] bytes, int offset, int count)
 395                 {
 396                         if (bytes == null)
 397                                 return null;
 398
 399                         if (bytes.Length == 0)
 400                                 return String.Empty;
 401
 402                         return Encoding.ASCII.GetString (UrlEncodeToBytes (bytes, offset, count));
 403                 }
 404
 405                 public static byte [] UrlEncodeToBytes (string str)
 406                 {
 407                         return UrlEncodeToBytes (str, Encoding.UTF8);
 408                 }
 409
 410                 public static byte [] UrlEncodeToBytes (string str, Encoding e)
 411                 {
 412                         if (str == null)
 413                                 return null;
 414
 415                         if (str.Length == 0)
 416                                 return new byte [0];
 417
 418                         byte [] bytes = e.GetBytes (str);
 419                         return UrlEncodeToBytes (bytes, 0, bytes.Length);
 420                 }
 421
 422                 public static byte [] UrlEncodeToBytes (byte [] bytes)
 423                 {
 424                         if (bytes == null)
 425                                 return null;
 426
 427                         if (bytes.Length == 0)
 428                                 return new byte [0];
 429
 430                         return UrlEncodeToBytes (bytes, 0, bytes.Length);
 431                 }
 432
 433                 public static byte [] UrlEncodeToBytes (byte [] bytes, int offset, int count)
 434                 {
 435                         if (bytes == null)
 436                                 return null;
 437 #if NET_4_0
 438                         return HttpEncoder.Current.UrlEncode (bytes, offset, count);
 439 #else
 440                         return HttpEncoder.UrlEncodeToBytes (bytes, offset, count);
 441 #endif
 442                 }
 443
 444                 public static string UrlEncodeUnicode (string str)
 445                 {
 446                         if (str == null)
 447                                 return null;
 448
 449                         return Encoding.ASCII.GetString (UrlEncodeUnicodeToBytes (str));
 450                 }
 451
 452                 public static byte [] UrlEncodeUnicodeToBytes (string str)
 453                 {
 454                         if (str == null)
 455                                 return null;
 456
 457                         if (str.Length == 0)
 458                                 return new byte [0];
 459
 460                         MemoryStream result = new MemoryStream (str.Length);
 461                         foreach (char c in str){
 462                                 HttpEncoder.UrlEncodeChar (c, result, true);
 463                         }
 464                         return result.ToArray ();
 465                 }
 466
 467                 /// <summary>
 468                 /// Decodes an HTML-encoded string and returns the decoded string.
 469                 /// </summary>
 470                 /// <param name="s">The HTML string to decode. </param>
 471                 /// <returns>The decoded text.</returns>
 472                 public static string HtmlDecode (string s)
 473                 {
 474 #if NET_4_0
 475                         if (s == null)
 476                                 return null;
 477
 478                         using (var sw = new StringWriter ()) {
 479                                 HttpEncoder.Current.HtmlDecode (s, sw);
 480                                 return sw.ToString ();
 481                         }
 482 #else
 483                         return HttpEncoder.HtmlDecode (s);
 484 #endif
 485                 }
 486
 487                 /// <summary>
 488                 /// Decodes an HTML-encoded string and sends the resulting output to a TextWriter output stream.
 489                 /// </summary>
 490                 /// <param name="s">The HTML string to decode</param>
 491                 /// <param name="output">The TextWriter output stream containing the decoded string. </param>
 492                 public static void HtmlDecode(string s, TextWriter output)
 493                 {
 494                         if (output == null) {
 495 #if NET_4_0
 496                                 throw new ArgumentNullException ("output");
 497 #else
 498                                 throw new NullReferenceException (".NET emulation");
 499 #endif
 500                         }
 501
 502                         if (!String.IsNullOrEmpty (s)) {
 503 #if NET_4_0
 504                                 HttpEncoder.Current.HtmlDecode (s, output);
 505 #else
 506                                 output.Write (HttpEncoder.HtmlDecode (s));
 507 #endif
 508                         }
 509                 }
 510
 511                 public static string HtmlEncode (string s)
 512                 {
 513 #if NET_4_0
 514                         if (s == null)
 515                                 return null;
 516
 517                         using (var sw = new StringWriter ()) {
 518                                 HttpEncoder.Current.HtmlEncode (s, sw);
 519                                 return sw.ToString ();
 520                         }
 521 #else
 522                         return HttpEncoder.HtmlEncode (s);
 523 #endif
 524                 }
 525
 526                 /// <summary>
 527                 /// HTML-encodes a string and sends the resulting output to a TextWriter output stream.
 528                 /// </summary>
 529                 /// <param name="s">The string to encode. </param>
 530                 /// <param name="output">The TextWriter output stream containing the encoded string. </param>
 531                 public static void HtmlEncode(string s, TextWriter output)
 532                 {
 533                         if (output == null) {
 534 #if NET_4_0
 535                                 throw new ArgumentNullException ("output");
 536 #else
 537                                 throw new NullReferenceException (".NET emulation");
 538 #endif
 539                         }
 540
 541                         if (!String.IsNullOrEmpty (s)) {
 542 #if NET_4_0
 543                                 HttpEncoder.Current.HtmlEncode (s, output);
 544 #else
 545                                 output.Write (HttpEncoder.HtmlEncode (s));
 546 #endif
 547                         }
 548                 }
 549 #if NET_4_0
 550                 public static string HtmlEncode (object value)
 551                 {
 552                         if (value == null)
 553                                 return null;
 554
 555                         IHtmlString htmlString = value as IHtmlString;
 556                         if (htmlString != null)
 557                                 return htmlString.ToHtmlString ();
 558
 559                         return HtmlEncode (value.ToString ());
 560                 }
 561
 562                 public static string JavaScriptStringEncode (string value)
 563                 {
 564                         return JavaScriptStringEncode (value, false);
 565                 }
 566
 567                 public static string JavaScriptStringEncode (string value, bool addDoubleQuotes)
 568                 {
 569                         if (String.IsNullOrEmpty (value))
 570                                 return addDoubleQuotes ? "\"\"" : String.Empty;
 571
 572                         int len = value.Length;
 573                         bool needEncode = false;
 574                         char c;
 575                         for (int i = 0; i < len; i++) {
 576                                 c = value [i];
 577
 578                                 if (c >= 0 && c <= 31 || c == 34 || c == 39 || c == 60 || c == 62 || c == 92) {
 579                                         needEncode = true;
 580                                         break;
 581                                 }
 582                         }
 583
 584                         if (!needEncode)
 585                                 return addDoubleQuotes ? "\"" + value + "\"" : value;
 586
 587                         var sb = new StringBuilder ();
 588                         if (addDoubleQuotes)
 589                                 sb.Append ('"');
 590
 591                         for (int i = 0; i < len; i++) {
 592                                 c = value [i];
 593                                 if (c >= 0 && c <= 7 || c == 11 || c >= 14 && c <= 31 || c == 39 || c == 60 || c == 62)
 594                                         sb.AppendFormat ("\\u{0:x4}", (int)c);
 595                                 else switch ((int)c) {
 596                                                 case 8:
 597                                                         sb.Append ("\\b");
 598                                                         break;
 599
 600                                                 case 9:
 601                                                         sb.Append ("\\t");
 602                                                         break;
 603
 604                                                 case 10:
 605                                                         sb.Append ("\\n");
 606                                                         break;
 607
 608                                                 case 12:
 609                                                         sb.Append ("\\f");
 610                                                         break;
 611
 612                                                 case 13:
 613                                                         sb.Append ("\\r");
 614                                                         break;
 615
 616                                                 case 34:
 617                                                         sb.Append ("\\\"");
 618                                                         break;
 619
 620                                                 case 92:
 621                                                         sb.Append ("\\\\");
 622                                                         break;
 623
 624                                                 default:
 625                                                         sb.Append (c);
 626                                                         break;
 627                                         }
 628                         }
 629
 630                         if (addDoubleQuotes)
 631                                 sb.Append ('"');
 632
 633                         return sb.ToString ();
 634                 }
 635 #endif
 636                 public static string UrlPathEncode (string s)
 637                 {
 638 #if NET_4_0
 639                         return HttpEncoder.Current.UrlPathEncode (s);
 640 #else
 641                         return HttpEncoder.UrlPathEncode (s);
 642 #endif
 643                 }
 644
 645                 public static NameValueCollection ParseQueryString (string query)
 646                 {
 647                         return ParseQueryString (query, Encoding.UTF8);
 648                 }
 649
 650                 public static NameValueCollection ParseQueryString (string query, Encoding encoding)
 651                 {
 652                         if (query == null)
 653                                 throw new ArgumentNullException ("query");
 654                         if (encoding == null)
 655                                 throw new ArgumentNullException ("encoding");
 656                         if (query.Length == 0 || (query.Length == 1 && query[0] == '?'))
 657                                 return new HttpQSCollection ();
 658                         if (query[0] == '?')
 659                                 query = query.Substring (1);
 660
 661                         NameValueCollection result = new HttpQSCollection ();
 662                         ParseQueryString (query, encoding, result);
 663                         return result;
 664                 }
 665
 666                 internal static void ParseQueryString (string query, Encoding encoding, NameValueCollection result)
 667                 {
 668                         if (query.Length == 0)
 669                                 return;
 670
 671                         string decoded = HtmlDecode (query);
 672                         int decodedLength = decoded.Length;
 673                         int namePos = 0;
 674                         bool first = true;
 675                         while (namePos <= decodedLength) {
 676                                 int valuePos = -1, valueEnd = -1;
 677                                 for (int q = namePos; q < decodedLength; q++) {
 678                                         if (valuePos == -1 && decoded [q] == '=') {
 679                                                 valuePos = q + 1;
 680                                         } else if (decoded [q] == '&') {
 681                                                 valueEnd = q;
 682                                                 break;
 683                                         }
 684                                 }
 685
 686                                 if (first) {
 687                                         first = false;
 688                                         if (decoded [namePos] == '?')
 689                                                 namePos++;
 690                                 }
 691
 692                                 string name, value;
 693                                 if (valuePos == -1) {
 694                                         name = null;
 695                                         valuePos = namePos;
 696                                 } else {
 697                                         name = UrlDecode (decoded.Substring (namePos, valuePos - namePos - 1), encoding);
 698                                 }
 699                                 if (valueEnd < 0) {
 700                                         namePos = -1;
 701                                         valueEnd = decoded.Length;
 702                                 } else {
 703                                         namePos = valueEnd + 1;
 704                                 }
 705                                 value = UrlDecode (decoded.Substring (valuePos, valueEnd - valuePos), encoding);
 706
 707                                 result.Add (name, value);
 708                                 if (namePos == -1)
 709                                         break;
 710                         }
 711                 }
 712                 #endregion // Methods
 713         }
 714 }
 715