mcs/class/System.Net.Http/System.Net.Http.Headers/ContentDispositionHeaderValue.cs

   1 //
   2 // ContentDispositionHeaderValue.cs
   3 //
   4 // Authors:
   5 //      Marek Safar  <marek.safar@gmail.com>
   6 //
   7 // Copyright (C) 2012 Xamarin Inc (http://www.xamarin.com)
   8 //
   9 // Permission is hereby granted, free of charge, to any person obtaining
  10 // a copy of this software and associated documentation files (the
  11 // "Software"), to deal in the Software without restriction, including
  12 // without limitation the rights to use, copy, modify, merge, publish,
  13 // distribute, sublicense, and/or sell copies of the Software, and to
  14 // permit persons to whom the Software is furnished to do so, subject to
  15 // the following conditions:
  16 //
  17 // The above copyright notice and this permission notice shall be
  18 // included in all copies or substantial portions of the Software.
  19 //
  20 // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
  21 // EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  22 // MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
  23 // NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
  24 // LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
  25 // OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
  26 // WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  27 //
  28
  29 using System.Collections.Generic;
  30 using System.Text;
  31 using System.Globalization;
  32
  33 namespace System.Net.Http.Headers
  34 {
  35         public class ContentDispositionHeaderValue : ICloneable
  36         {
  37                 string dispositionType;
  38                 List<NameValueHeaderValue> parameters;
  39
  40                 private ContentDispositionHeaderValue ()
  41                 {
  42                 }
  43
  44                 public ContentDispositionHeaderValue (string dispositionType)
  45                 {
  46                         DispositionType = dispositionType;
  47                 }
  48
  49                 protected ContentDispositionHeaderValue (ContentDispositionHeaderValue source)
  50                 {
  51                         if (source == null)
  52                                 throw new ArgumentNullException ("source");
  53
  54                         dispositionType = source.dispositionType;
  55                         if (source.parameters != null) {
  56                                 foreach (var item in source.parameters)
  57                                         Parameters.Add (new NameValueHeaderValue (item));
  58                         }
  59                 }
  60
  61                 public DateTimeOffset? CreationDate {
  62                         get {
  63                                 return GetDateValue ("creation-date");
  64                         }
  65                         set {
  66                                 SetDateValue ("creation-date", value);
  67                         }
  68                 }
  69
  70                 public string DispositionType {
  71                         get {
  72                                 return dispositionType;
  73                         }
  74                         set {
  75                                 Parser.Token.Check (value);
  76                                 dispositionType = value;
  77                         }
  78                 }
  79
  80                 public string FileName {
  81                         get {
  82                                 var value = FindParameter ("filename");
  83                                 if (value == null)
  84                                         return null;
  85
  86                                 return DecodeValue (value, false);
  87                         }
  88                         set {
  89                                 if (value != null)
  90                                         value = EncodeBase64Value (value);
  91
  92                                 SetValue ("filename", value);
  93                         }
  94                 }
  95
  96                 public string FileNameStar {
  97                         get {
  98                                 var value = FindParameter ("filename*");
  99                                 if (value == null)
 100                                         return null;
 101
 102                                 return DecodeValue (value, true);
 103                         }
 104                         set {
 105                                 if (value != null)
 106                                         value = EncodeRFC5987 (value);
 107
 108                                 SetValue ("filename*", value);
 109                         }
 110                 }
 111
 112                 public DateTimeOffset? ModificationDate {
 113                         get {
 114                                 return GetDateValue ("modification-date");
 115                         }
 116                         set {
 117                                 SetDateValue ("modification-date", value);
 118                         }
 119                 }
 120
 121                 public string Name {
 122                         get {
 123                                 var value = FindParameter ("name");
 124
 125                                 if (value == null)
 126                                         return null;
 127
 128                                 return DecodeValue (value, false);
 129                         }
 130                         set {
 131                                 if (value != null)
 132                                         value = EncodeBase64Value (value);
 133
 134                                 SetValue ("name", value);
 135                         }
 136                 }
 137
 138                 public ICollection<NameValueHeaderValue> Parameters {
 139                         get {
 140                                 return parameters ?? (parameters = new List<NameValueHeaderValue> ());
 141                         }
 142                 }
 143
 144                 public DateTimeOffset? ReadDate {
 145                         get {
 146                                 return GetDateValue ("read-date");
 147                         }
 148                         set {
 149                                 SetDateValue ("read-date", value);
 150                         }
 151                 }
 152
 153                 public long? Size {
 154                         get {
 155                                 var found = FindParameter ("size");
 156                                 long result;
 157                                 if (Parser.Long.TryParse (found, out result))
 158                                         return result;
 159
 160                                 return null;
 161                         }
 162                         set {
 163                                 if (value == null) {
 164                                         SetValue ("size", null);
 165                                         return;
 166                                 }
 167
 168                                 if (value < 0)
 169                                         throw new ArgumentOutOfRangeException ("value");
 170
 171                                 SetValue ("size", value.Value.ToString (CultureInfo.InvariantCulture));
 172                         }
 173                 }
 174
 175                 object ICloneable.Clone ()
 176                 {
 177                         return new ContentDispositionHeaderValue (this);
 178                 }
 179
 180                 public override bool Equals (object obj)
 181                 {
 182                         var source = obj as ContentDispositionHeaderValue;
 183                         return source != null &&
 184                                 string.Equals (source.dispositionType, dispositionType, StringComparison.OrdinalIgnoreCase) &&
 185                                 source.parameters.SequenceEqual (parameters);
 186                 }
 187
 188                 string FindParameter (string name)
 189                 {
 190                         if (parameters == null)
 191                                 return null;
 192
 193                         foreach (var entry in parameters) {
 194                                 if (string.Equals (entry.Name, name, StringComparison.OrdinalIgnoreCase))
 195                                         return entry.Value;
 196                         }
 197
 198                         return null;
 199                 }
 200
 201                 DateTimeOffset? GetDateValue (string name)
 202                 {
 203                         var value = FindParameter (name);
 204                         if (value == null || value == null)
 205                                 return null;
 206
 207                         if (value.Length < 3)
 208                                 return null;
 209
 210                         if (value[0] == '\"')
 211                                 value = value.Substring (1, value.Length - 2);
 212
 213                         DateTimeOffset offset;
 214                         if (Lexer.TryGetDateValue (value, out offset))
 215                                 return offset;
 216
 217                         return null;
 218                 }
 219
 220                 static string EncodeBase64Value (string value)
 221                 {
 222                         bool quoted = value.Length > 1 && value [0] == '"' && value [value.Length - 1] == '"';
 223                         if (quoted)
 224                                 value = value.Substring (1, value.Length - 2);
 225
 226                         for (int i = 0; i < value.Length; ++i) {
 227                                 var ch = value[i];
 228                                 if (ch > 127) {
 229                                         var encoding = Encoding.UTF8;
 230                                         return string.Format ("\"=?{0}?B?{1}?=\"",
 231                                                 encoding.WebName, Convert.ToBase64String (encoding.GetBytes (value)));
 232                                 }
 233                         }
 234
 235                         if (quoted || !Lexer.IsValidToken (value))
 236                                 return "\"" + value + "\"";
 237
 238                         return value;
 239                 }
 240
 241                 static string EncodeRFC5987 (string value)
 242                 {
 243                         var encoding = Encoding.UTF8;
 244                         StringBuilder sb = new StringBuilder (value.Length + 11);
 245                         sb.Append (encoding.WebName);
 246                         sb.Append ('\'');
 247                         sb.Append ('\'');
 248
 249                         for (int i = 0; i < value.Length; ++i) {
 250                                 var ch = value[i];
 251                                 if (ch > 127) {
 252                                         foreach (var b in encoding.GetBytes (new[] { ch })) {
 253                                                 sb.Append ('%');
 254                                                 sb.Append (b.ToString ("X2"));
 255                                         }
 256
 257                                         continue;
 258                                 }
 259
 260                                 if (!Lexer.IsValidCharacter (ch) || ch == '*' || ch == '?' || ch == '%') {
 261                                         sb.Append (Uri.HexEscape (ch));
 262                                         continue;
 263                                 }
 264
 265                                 sb.Append (ch);
 266                         }
 267
 268                         return sb.ToString ();
 269                 }
 270
 271                 static string DecodeValue (string value, bool extendedNotation)
 272                 {
 273                         //
 274                         // A short (length <= 78 characters)
 275                         // parameter value containing only non-`tspecials' characters SHOULD be
 276                         // represented as a single `token'.  A short parameter value containing
 277                         // only ASCII characters, but including `tspecials' characters, SHOULD
 278                         // be represented as `quoted-string'.  Parameter values longer than 78
 279                         // characters, or which contain non-ASCII characters, MUST be encoded as
 280                         // specified in [RFC 2184].
 281                         //
 282                         if (value.Length < 2)
 283                                 return value;
 284
 285                         string[] sep;
 286                         Encoding encoding;
 287
 288                         // Quoted string
 289                         if (value[0] == '\"') {
 290                                 //
 291                                 // Is Base64 encoded ?
 292                                 // encoded-word := "=?" charset "?" encoding "?" encoded-text "?="
 293                                 //
 294                                 sep = value.Split ('?');
 295                                 if (sep.Length != 5 || sep[0] != "\"=" || sep[4] != "=\"" || (sep[2] != "B" && sep[2] != "b"))
 296                                         return value;
 297
 298                                 try {
 299                                         encoding = Encoding.GetEncoding (sep[1]);
 300                                         return encoding.GetString (Convert.FromBase64String (sep[3]));
 301                                 } catch {
 302                                         return value;
 303                                 }
 304                         }
 305
 306                         if (!extendedNotation)
 307                                 return value;
 308
 309                         //
 310                         // RFC 5987: Charset/Language Encoding
 311                         //
 312                         sep = value.Split ('\'');
 313                         if (sep.Length != 3)
 314                                 return null;
 315
 316                         try {
 317                                 encoding = Encoding.GetEncoding (sep[0]);
 318                         } catch {
 319                                 return null;
 320                         }
 321
 322                         // TODO: What to do with sep[1] language
 323
 324                         value = sep[2];
 325
 326                         int pct_encoded = value.IndexOf ('%');
 327                         if (pct_encoded < 0)
 328                                 return value;
 329
 330                         StringBuilder sb = new StringBuilder ();
 331                         byte[] buffer = null;
 332                         int buffer_pos = 0;
 333
 334                         for (int i = 0; i < value.Length;) {
 335                                 var ch = value[i];
 336                                 if (ch == '%') {
 337                                         var unescaped = ch;
 338                                         ch = Uri.HexUnescape (value, ref i);
 339                                         if (ch != unescaped) {
 340                                                 if (buffer == null)
 341                                                         buffer = new byte[value.Length - i + 1];
 342
 343                                                 buffer[buffer_pos++] = (byte) ch;
 344                                                 continue;
 345                                         }
 346                                 } else {
 347                                         ++i;
 348                                 }
 349
 350                                 if (buffer_pos != 0) {
 351                                         sb.Append (encoding.GetChars (buffer, 0, buffer_pos));
 352                                         buffer_pos = 0;
 353                                 }
 354
 355                                 sb.Append (ch);
 356                         }
 357
 358                         if (buffer_pos != 0) {
 359                                 sb.Append (encoding.GetChars (buffer, 0, buffer_pos));
 360                         }
 361
 362                         return sb.ToString ();
 363                 }
 364
 365                 public override int GetHashCode ()
 366                 {
 367                         return dispositionType.ToLowerInvariant ().GetHashCode () ^
 368                                 HashCodeCalculator.Calculate (parameters);
 369                 }
 370
 371                 public static ContentDispositionHeaderValue Parse (string input)
 372                 {
 373                         ContentDispositionHeaderValue value;
 374                         if (TryParse (input, out value))
 375                                 return value;
 376
 377                         throw new FormatException (input);
 378                 }
 379
 380                 void SetDateValue (string key, DateTimeOffset? value)
 381                 {
 382                         SetValue (key, value == null ? null : ("\"" + value.Value.ToString ("r", CultureInfo.InvariantCulture)) + "\"");
 383                 }
 384
 385                 void SetValue (string key, string value)
 386                 {
 387                         if (parameters == null)
 388                                 parameters = new List<NameValueHeaderValue> ();
 389
 390                         parameters.SetValue (key, value);
 391                 }
 392
 393                 public override string ToString ()
 394                 {
 395                         return dispositionType + CollectionExtensions.ToString (parameters);
 396                 }
 397
 398                 public static bool TryParse (string input, out ContentDispositionHeaderValue parsedValue)
 399                 {
 400                         parsedValue = null;
 401
 402                         var lexer = new Lexer (input);
 403                         var t = lexer.Scan ();
 404                         if (t.Kind != Token.Type.Token)
 405                                 return false;
 406
 407                         List<NameValueHeaderValue> parameters = null;
 408                         var type = lexer.GetStringValue (t);
 409
 410                         t = lexer.Scan ();
 411
 412                         switch (t.Kind) {
 413                         case Token.Type.SeparatorSemicolon:
 414                                 if (!NameValueHeaderValue.TryParseParameters (lexer, out parameters, out t) || t != Token.Type.End)
 415                                         return false;
 416                                 break;
 417                         case Token.Type.End:
 418                                 break;
 419                         default:
 420                                 return false;
 421                         }
 422
 423                         parsedValue = new ContentDispositionHeaderValue () {
 424                                 dispositionType = type,
 425                                 parameters = parameters
 426                         };
 427
 428                         return true;
 429                 }
 430         }
 431 }