mcs/class/corlib/System.Security.Permissions/UrlIdentityPermission.cs

   1 //
   2 // System.Security.Permissions.UrlIdentityPermission.cs
   3 //
   4 // Author
   5 //      Sebastien Pouliot  <sebastien@ximian.com>
   6 //
   7 // Copyright (C) 2003 Motus Technologies. http://www.motus.com
   8 // Copyright (C) 2004-2005 Novell, Inc (http://www.novell.com)
   9 //
  10 // Permission is hereby granted, free of charge, to any person obtaining
  11 // a copy of this software and associated documentation files (the
  12 // "Software"), to deal in the Software without restriction, including
  13 // without limitation the rights to use, copy, modify, merge, publish,
  14 // distribute, sublicense, and/or sell copies of the Software, and to
  15 // permit persons to whom the Software is furnished to do so, subject to
  16 // the following conditions:
  17 //
  18 // The above copyright notice and this permission notice shall be
  19 // included in all copies or substantial portions of the Software.
  20 //
  21 // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
  22 // EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  23 // MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
  24 // NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
  25 // LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
  26 // OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
  27 // WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  28 //
  29
  30 using System.Globalization;
  31 using System.Runtime.InteropServices;
  32
  33 namespace System.Security.Permissions {
  34
  35         [Serializable]
  36 #if NET_2_0
  37         [ComVisible (true)]
  38 #endif
  39         public sealed class UrlIdentityPermission : CodeAccessPermission, IBuiltInPermission {
  40
  41                 private const int version = 1;
  42
  43                 private string url;
  44
  45                 public UrlIdentityPermission (PermissionState state)
  46                 {
  47                         // false == do not allow Unrestricted for Identity Permissions
  48                         CheckPermissionState (state, false);
  49 #if NET_2_0
  50                         url = String.Empty;
  51 #endif
  52                 }
  53
  54                 public UrlIdentityPermission (string site)
  55                 {
  56                         if (site == null)
  57                                 throw new ArgumentNullException ("site");
  58                         url = site;
  59                 }
  60
  61 #if NET_2_0
  62                 public string Url {
  63                         get { return url; }
  64                         set { url = ((value == null) ? String.Empty : value); }
  65                 }
  66 #else
  67                 public string Url {
  68                         get {
  69                                 if (url == null)
  70                                         throw new NullReferenceException ("Url");
  71                                 return url;
  72                         }
  73                         set {
  74                                 if (value == null)
  75                                         throw new ArgumentNullException ("Url");
  76                                 url = value;
  77                         }
  78                 }
  79 #endif
  80
  81                 public override IPermission Copy ()
  82                 {
  83                         if (url == null) {
  84 #if NET_2_0
  85                                 return new UrlIdentityPermission (PermissionState.None);
  86 #else
  87                                 throw new NullReferenceException ("Url");
  88 #endif
  89                         }
  90                         else
  91                                 return new UrlIdentityPermission (url);
  92                 }
  93
  94                 public override void FromXml (SecurityElement esd)
  95                 {
  96                         // General validation in CodeAccessPermission
  97                         CheckSecurityElement (esd, "esd", 1, 1);
  98                         // Note: we do not (yet) care about the return value
  99                         // as we only accept version 1 (min/max values)
 100
 101                         string u = esd.Attribute ("Url");
 102                         if (u == null)
 103                                 url = String.Empty;
 104                         else
 105                                 Url = u;
 106                 }
 107
 108                 public override IPermission Intersect (IPermission target)
 109                 {
 110                         // if one permission is null (object or url) then there's no intersection
 111                         // if both are null then intersection is null
 112                         UrlIdentityPermission uip = Cast (target);
 113                         if ((uip == null) || (IsEmpty ()))
 114                                 return null;
 115                         if (Match (uip.url)) {
 116                                 // longest form is the intersection
 117                                 if (url.Length > uip.url.Length)
 118                                         return Copy ();
 119                                 else
 120                                         return uip.Copy ();
 121                         }
 122                         return null;
 123                 }
 124
 125                 public override bool IsSubsetOf (IPermission target)
 126                 {
 127                         UrlIdentityPermission uip = Cast (target);
 128                         if (uip == null)
 129                                 return IsEmpty ();
 130                         if (IsEmpty ())
 131                                 return true;
 132                         if (uip.url == null)
 133                                 return false;
 134
 135                         // here Match wouldn't work as it is bidirectional
 136                         int wildcard = uip.url.LastIndexOf ('*');
 137                         if (wildcard == -1)
 138                                 wildcard = uip.url.Length;      // exact match
 139
 140                         return (String.Compare (url, 0, uip.url, 0, wildcard, true, CultureInfo.InvariantCulture) == 0);
 141                 }
 142
 143                 public override SecurityElement ToXml ()
 144                 {
 145                         SecurityElement se = Element (version);
 146                         if (!IsEmpty ())
 147                                 se.AddAttribute ("Url", url);
 148                         return se;
 149                 }
 150
 151                 public override IPermission Union (IPermission target)
 152                 {
 153                         UrlIdentityPermission uip = Cast (target);
 154                         if (uip == null)
 155                                 return Copy ();
 156                         if (IsEmpty () && uip.IsEmpty ())
 157                                 return null;
 158                         if (uip.IsEmpty ())
 159                                 return Copy ();
 160                         if (IsEmpty ())
 161                                 return uip.Copy ();
 162                         if (Match (uip.url)) {
 163                                 // shortest form is the union
 164                                 if (url.Length < uip.url.Length)
 165                                         return Copy ();
 166                                 else
 167                                         return uip.Copy ();
 168                         }
 169 #if NET_2_0
 170                         throw new ArgumentException (Locale.GetText (
 171                                 "Cannot union two different urls."), "target");
 172 #else
 173                         return null;
 174 #endif
 175                 }
 176
 177                 // IBuiltInPermission
 178                 int IBuiltInPermission.GetTokenIndex ()
 179                 {
 180                         return (int) BuiltInToken.UrlIdentity;
 181                 }
 182
 183                 // helpers
 184
 185                 private bool IsEmpty ()
 186                 {
 187                         return ((url == null) || (url.Length == 0));
 188                 }
 189
 190                 private UrlIdentityPermission Cast (IPermission target)
 191                 {
 192                         if (target == null)
 193                                 return null;
 194
 195                         UrlIdentityPermission uip = (target as UrlIdentityPermission);
 196                         if (uip == null) {
 197                                 ThrowInvalidPermission (target, typeof (UrlIdentityPermission));
 198                         }
 199
 200                         return uip;
 201                 }
 202
 203                 private bool Match (string target)
 204                 {
 205                         if ((url == null) || (target == null))
 206                                 return false;
 207
 208                         int wcu = url.LastIndexOf ('*');
 209                         int wct = target.LastIndexOf ('*');
 210                         int length = Int32.MaxValue;
 211
 212                         if ((wcu == -1) && (wct == -1)) {
 213                                 // no wildcard, this is an exact match
 214                                 length = Math.Max (url.Length, target.Length);
 215                         }
 216                         else if (wcu == -1) {
 217                                 // only "this" has a wildcard, use it
 218                                 length = wct;
 219                         }
 220                         else if (wct == -1) {
 221                                 // only "target" has a wildcard, use it
 222                                 length = wcu;
 223                         }
 224                         else {
 225                                 // both have wildcards, partial match with the smallest
 226                                 length = Math.Min (wcu, wct);
 227                         }
 228
 229                         return (String.Compare (url, 0, target, 0, length, true, CultureInfo.InvariantCulture) == 0);
 230                 }
 231         }
 232 }