class/corlib/System.Security/SecurityElement.cs

   1 //
   2 // System.Security.SecurityElement.cs
   3 //
   4 // Authors:
   5 //      Miguel de Icaza (miguel@ximian.com)
   6 //      Lawrence Pit (loz@cable.a2000.nl)
   7 //      Sebastien Pouliot  <sebastien@ximian.com>
   8 //
   9 // (C) Ximian, Inc. http://www.ximian.com
  10 // Copyright (C) 2004-2005 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.Globalization;
  33 using System.Collections;
  34 using System.Runtime.InteropServices;
  35 using System.Text;
  36
  37 using Mono.Xml;
  38
  39 namespace System.Security {
  40
  41         [ComVisible (true)]
  42         [Serializable]
  43         public sealed class SecurityElement
  44         {
  45                 internal class SecurityAttribute {
  46
  47                         private string _name;
  48                         private string _value;
  49
  50                         public SecurityAttribute (string name, string value)
  51                         {
  52                                 if (!IsValidAttributeName (name))
  53                                         throw new ArgumentException (Locale.GetText ("Invalid XML attribute name") + ": " + name);
  54
  55                                 if (!IsValidAttributeValue (value))
  56                                         throw new ArgumentException (Locale.GetText ("Invalid XML attribute value") + ": " + value);
  57
  58                                 _name = name;
  59                                 _value = SecurityElement.Unescape (value);
  60                         }
  61
  62                         public string Name {
  63                                 get { return _name; }
  64                         }
  65
  66                         public string Value {
  67                                 get { return _value; }
  68                         }
  69                 }
  70
  71                 string text;
  72                 string tag;
  73                 ArrayList attributes;
  74                 ArrayList children;
  75
  76                 // these values are determined by a simple test program against the MS.Net implementation:
  77                 //      for (int i = 0; i < 256; i++) {
  78                 //              if (!SecurityElement.IsValidTag ("" + ((char) i))) {
  79                 //                      System.Console.WriteLine ("TAG: " + i);
  80                 //              }
  81                 //      }
  82                 // note: this is actually an incorrect implementation of MS, as for example the &
  83                 // character is not a valid character in tag names.
  84                 private static readonly char [] invalid_tag_chars = new char [] { ' ', '<', '>' };
  85                 private static readonly char [] invalid_text_chars = new char [] { '<', '>' };
  86                 private static readonly char [] invalid_attr_name_chars = new char [] { ' ', '<', '>' };
  87                 private static readonly char [] invalid_attr_value_chars = new char [] { '"', '<', '>' };
  88                 private static readonly char [] invalid_chars = new char [] { '<', '>', '"', '\'', '&' };
  89
  90                 public SecurityElement (string tag) : this (tag, null)
  91                 {
  92                 }
  93
  94                 public SecurityElement (string tag, string text)
  95                 {
  96                         if (tag == null)
  97                                 throw new ArgumentNullException ("tag");
  98                         if (!IsValidTag (tag))
  99                                 throw new ArgumentException (Locale.GetText ("Invalid XML string") + ": " + tag);
 100                         this.tag = tag;
 101
 102                         Text = text;
 103                 }
 104
 105                 // not a deep copy (childs are references)
 106                 internal SecurityElement (SecurityElement se)
 107                 {
 108                         this.Tag = se.Tag;
 109                         this.Text = se.Text;
 110
 111                         if (se.attributes != null) {
 112                                 foreach (SecurityAttribute sa in se.attributes) {
 113                                         this.AddAttribute (sa.Name, sa.Value);
 114                                 }
 115                         }
 116                         if (se.children != null) {
 117                                 foreach (SecurityElement child in se.children) {
 118                                         this.AddChild (child);
 119                                 }
 120                         }
 121                 }
 122
 123                 public Hashtable Attributes {
 124                         get {
 125                                 if (attributes == null)
 126                                         return null;
 127
 128                                 Hashtable result = new Hashtable (attributes.Count);
 129                                 foreach (SecurityAttribute sa in attributes) {
 130                                         result.Add (sa.Name, sa.Value);
 131                                 }
 132                                 return result;
 133                         }
 134
 135                         set {
 136                                 if (value == null || value.Count == 0) {
 137                                         attributes.Clear ();
 138                                         return;
 139                                 }
 140
 141                                 if (attributes == null)
 142                                         attributes = new ArrayList ();
 143                                 else
 144                                         attributes.Clear ();
 145                                 IDictionaryEnumerator e = value.GetEnumerator ();
 146                                 while (e.MoveNext ()) {
 147                                         attributes.Add (new SecurityAttribute ((string) e.Key, (string) e.Value));
 148                                 }
 149                         }
 150                 }
 151
 152                 public ArrayList Children {
 153                         get {
 154                                 return children;
 155                         }
 156
 157                         set {
 158                                 if (value != null) {
 159                                         foreach (object o in value) {
 160                                                 if (o == null)
 161                                                         throw new ArgumentNullException ();
 162                                                 // shouldn't we also throw an exception
 163                                                 // when o isn't an instance of SecurityElement?
 164                                         }
 165                                 }
 166                                 children = value;
 167                         }
 168                 }
 169
 170                 public string Tag {
 171                         get {
 172                                 return tag;
 173                         }
 174                         set {
 175                                 if (value == null)
 176                                         throw new ArgumentNullException ("Tag");
 177                                 if (!IsValidTag (value))
 178                                         throw new ArgumentException (Locale.GetText ("Invalid XML string") + ": " + value);
 179                                 tag = value;
 180                         }
 181                 }
 182
 183                 public string Text {
 184                         get {
 185                                 return text;
 186                         }
 187
 188                         set {
 189                                 if (value != null) {
 190                                         if (!IsValidText (value))
 191                                                 throw new ArgumentException (
 192                                                         Locale.GetText ("Invalid XML string")
 193                                                         + ": " + value);
 194                                 }
 195                                 text = Unescape (value);
 196                         }
 197                 }
 198
 199                 public void AddAttribute (string name, string value)
 200                 {
 201                         if (name == null)
 202                                 throw new ArgumentNullException ("name");
 203                         if (value == null)
 204                                 throw new ArgumentNullException ("value");
 205                         if (GetAttribute (name) != null)
 206                                 throw new ArgumentException (Locale.GetText ("Duplicate attribute : " + name));
 207
 208                         if (attributes == null)
 209                                 attributes = new ArrayList ();
 210                         attributes.Add (new SecurityAttribute (name, value));
 211                 }
 212
 213                 public void AddChild (SecurityElement child)
 214                 {
 215                         if (child == null)
 216                                 throw new ArgumentNullException ("child");
 217
 218                         if (children == null)
 219                                 children = new ArrayList ();
 220
 221                         children.Add (child);
 222                 }
 223
 224                 public string Attribute (string name)
 225                 {
 226                         if (name == null)
 227                                 throw new ArgumentNullException ("name");
 228
 229                         SecurityAttribute sa = GetAttribute (name);
 230                         return ((sa == null) ? null : sa.Value);
 231                 }
 232
 233                 [ComVisible (false)]
 234                 public SecurityElement Copy ()
 235                 {
 236                         return new SecurityElement (this);
 237                 }
 238
 239                 public bool Equal (SecurityElement other)
 240                 {
 241                         if (other == null)
 242                                 return false;
 243
 244                         if (this == other)
 245                                 return true;
 246
 247                         if (this.text != other.text)
 248                                 return false;
 249
 250                         if (this.tag != other.tag)
 251                                 return false;
 252
 253                         if (this.attributes == null && other.attributes != null && other.attributes.Count != 0)
 254                                 return false;
 255
 256                         if (other.attributes == null && this.attributes != null && this.attributes.Count != 0)
 257                                 return false;
 258
 259                         if (this.attributes != null && other.attributes != null) {
 260                                 if (this.attributes.Count != other.attributes.Count)
 261                                         return false;
 262                                 foreach (SecurityAttribute sa1 in attributes) {
 263                                         SecurityAttribute sa2 = other.GetAttribute (sa1.Name);
 264                                         if ((sa2 == null) || (sa1.Value != sa2.Value))
 265                                                 return false;
 266                                 }
 267                         }
 268
 269                         if (this.children == null && other.children != null && other.children.Count != 0)
 270                                 return false;
 271
 272                         if (other.children == null && this.children != null && this.children.Count != 0)
 273                                 return false;
 274
 275                         if (this.children != null && other.children != null) {
 276                                 if (this.children.Count != other.children.Count)
 277                                         return false;
 278                                 for (int i = 0; i < this.children.Count; i++)
 279                                         if (!((SecurityElement) this.children [i]).Equal ((SecurityElement) other.children [i]))
 280                                                 return false;
 281                         }
 282
 283                         return true;
 284                 }
 285
 286                 public static string Escape (string str)
 287                 {
 288                         StringBuilder sb;
 289
 290                         if (str == null)
 291                                 return null;
 292
 293                         if (str.IndexOfAny (invalid_chars) == -1)
 294                                 return str;
 295
 296                         sb = new StringBuilder ();
 297                         int len = str.Length;
 298
 299                         for (int i = 0; i < len; i++) {
 300                                 char c = str [i];
 301
 302                                 switch (c) {
 303                                 case '<':  sb.Append ("&lt;"); break;
 304                                 case '>':  sb.Append ("&gt;"); break;
 305                                 case '"':  sb.Append ("&quot;"); break;
 306                                 case '\'': sb.Append ("&apos;"); break;
 307                                 case '&':  sb.Append ("&amp;"); break;
 308                                 default:   sb.Append (c); break;
 309                                 }
 310                         }
 311
 312                         return sb.ToString ();
 313                 }
 314
 315                 private static string Unescape (string str)
 316                 {
 317                         StringBuilder sb;
 318
 319                         if (str == null)
 320                                 return null;
 321
 322                         sb = new StringBuilder (str);
 323                         sb.Replace ("&lt;", "<");
 324                         sb.Replace ("&gt;", ">");
 325                         sb.Replace ("&amp;", "&");
 326                         sb.Replace ("&quot;", "\"");
 327                         sb.Replace ("&apos;", "'");
 328                         return sb.ToString ();
 329                 }
 330
 331                 public static SecurityElement FromString (string xml)
 332                 {
 333                         if (xml == null)
 334                                 throw new ArgumentNullException ("xml");
 335                         if (xml.Length == 0)
 336                                 throw new XmlSyntaxException (Locale.GetText ("Empty string."));
 337
 338                         try {
 339                                 SecurityParser sp = new SecurityParser ();
 340                                 sp.LoadXml (xml);
 341                                 return sp.ToXml ();
 342                         } catch (Exception e) {
 343                                 string msg = Locale.GetText ("Invalid XML.");
 344                                 throw new XmlSyntaxException (msg, e);
 345                         }
 346                 }
 347
 348                 public static bool IsValidAttributeName (string name)
 349                 {
 350                         return name != null && name.IndexOfAny (invalid_attr_name_chars) == -1;
 351                 }
 352
 353                 public static bool IsValidAttributeValue (string value)
 354                 {
 355                         return value != null && value.IndexOfAny (invalid_attr_value_chars) == -1;
 356                 }
 357
 358                 public static bool IsValidTag (string tag)
 359                 {
 360                         return tag != null && tag.IndexOfAny (invalid_tag_chars) == -1;
 361                 }
 362
 363                 public static bool IsValidText (string text)
 364                 {
 365                         return text != null && text.IndexOfAny (invalid_text_chars) == -1;
 366                 }
 367
 368                 public SecurityElement SearchForChildByTag (string tag)
 369                 {
 370                         if (tag == null)
 371                                 throw new ArgumentNullException ("tag");
 372
 373                         if (this.children == null)
 374                                 return null;
 375
 376                         for (int i = 0; i < children.Count; i++) {
 377                                 SecurityElement elem = (SecurityElement) children [i];
 378                                 if (elem.tag == tag)
 379                                         return elem;
 380                         }
 381                         return null;
 382                 }
 383
 384                 public string SearchForTextOfTag (string tag)
 385                 {
 386                         if (tag == null)
 387                                 throw new ArgumentNullException ("tag");
 388
 389                         if (this.tag == tag)
 390                                 return this.text;
 391
 392                         if (this.children == null)
 393                                 return null;
 394
 395                         for (int i = 0; i < children.Count; i++) {
 396                                 string result = ((SecurityElement) children [i]).SearchForTextOfTag (tag);
 397                                 if (result != null)
 398                                         return result;
 399                         }
 400
 401                         return null;
 402                 }
 403
 404                 public override string ToString ()
 405                 {
 406                         StringBuilder s = new StringBuilder ();
 407                         ToXml (ref s, 0);
 408                         return s.ToString ();
 409                 }
 410
 411                 private void ToXml (ref StringBuilder s, int level)
 412                 {
 413                         s.Append ("<");
 414                         s.Append (tag);
 415
 416                         if (attributes != null) {
 417                                 s.Append (" ");
 418                                 for (int i=0; i < attributes.Count; i++) {
 419                                         SecurityAttribute sa = (SecurityAttribute) attributes [i];
 420                                         s.Append (sa.Name)
 421                                          .Append ("=\"")
 422                                          .Append (Escape (sa.Value))
 423                                          .Append ("\"");
 424                                         if (i != attributes.Count - 1)
 425                                                 s.Append (Environment.NewLine);
 426                                 }
 427                         }
 428
 429                         if ((text == null || text == String.Empty) &&
 430                             (children == null || children.Count == 0))
 431                                 s.Append ("/>").Append (Environment.NewLine);
 432                         else {
 433                                 s.Append (">").Append (Escape (text));
 434                                 if (children != null) {
 435                                         s.Append (Environment.NewLine);
 436                                         foreach (SecurityElement child in children) {
 437                                                 child.ToXml (ref s, level + 1);
 438                                         }
 439 #if ! NET_2_0
 440                                         s.Append (' ', level * 3);
 441 #endif
 442                                 }
 443                                 s.Append ("</")
 444                                  .Append (tag)
 445                                  .Append (">")
 446                                  .Append (Environment.NewLine);
 447                         }
 448                 }
 449
 450                 internal SecurityAttribute GetAttribute (string name)
 451                 {
 452                         if (attributes != null) {
 453                                 foreach (SecurityAttribute sa in attributes) {
 454                                         if (sa.Name == name)
 455                                                 return sa;
 456                                 }
 457                         }
 458                         return null;
 459                 }
 460         }
 461 }