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

   1 //
   2 // System.Security.Permissions.SiteIdentityPermission.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 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
  32 namespace System.Security.Permissions {
  33
  34         [Serializable]
  35         public sealed class SiteIdentityPermission : CodeAccessPermission, IBuiltInPermission {
  36
  37                 private const int version = 1;
  38
  39                 private string _site;
  40
  41                 // Constructors
  42
  43                 public SiteIdentityPermission (PermissionState state)
  44                 {
  45                         // false == do not allow Unrestricted for Identity Permissions
  46                         CheckPermissionState (state, false);
  47                 }
  48
  49                 public SiteIdentityPermission (string site)
  50                 {
  51                         Site = site;
  52                 }
  53
  54                 // Properties
  55
  56                 public string Site {
  57                         get {
  58                                 if (IsEmpty ())
  59                                         throw new NullReferenceException ("No site.");
  60                                 return _site;
  61                         }
  62                         set {
  63                                 if (!IsValid (value))
  64                                         throw new ArgumentException ("Invalid site.");
  65                                 _site = value;
  66                         }
  67                 }
  68
  69                 // Methods
  70
  71                 public override IPermission Copy ()
  72                 {
  73                         if (IsEmpty ())
  74                                 return new SiteIdentityPermission (PermissionState.None);
  75                         else
  76                                 return new SiteIdentityPermission (_site);
  77                 }
  78
  79                 public override void FromXml (SecurityElement esd)
  80                 {
  81                         // General validation in CodeAccessPermission
  82                         CheckSecurityElement (esd, "esd", version, version);
  83                         // Note: we do not (yet) care about the return value
  84                         // as we only accept version 1 (min/max values)
  85
  86                         string s = esd.Attribute ("Site");
  87                         if (s != null)
  88                                 Site = s;
  89                 }
  90
  91                 public override IPermission Intersect (IPermission target)
  92                 {
  93                         SiteIdentityPermission sip = Cast (target);
  94                         if ((sip == null) || (IsEmpty ()))
  95                                 return null;
  96
  97                         if (Match (sip._site)) {
  98                                 string s = ((_site.Length > sip._site.Length) ? _site : sip._site);
  99                                 return new SiteIdentityPermission (s);
 100                         }
 101                         return null;
 102                 }
 103
 104                 public override bool IsSubsetOf (IPermission target)
 105                 {
 106                         SiteIdentityPermission sip = Cast (target);
 107                         if (sip == null)
 108                                 return IsEmpty ();
 109                         if ((_site == null) && (sip._site == null))
 110                                 return true;
 111                         if ((_site == null) || (sip._site == null))
 112                                 return false;
 113
 114                         int wildcard = sip._site.IndexOf ('*');
 115                         if (wildcard == -1) {
 116                                 // exact match
 117                                 return (_site == sip._site);
 118                         }
 119                         return _site.EndsWith (sip._site.Substring (wildcard + 1));
 120                 }
 121
 122                 public override SecurityElement ToXml ()
 123                 {
 124                         SecurityElement e = Element (version);
 125                         if (_site != null)
 126                                 e.AddAttribute ("Site", _site);
 127                         return e;
 128                 }
 129
 130                 public override IPermission Union (IPermission target)
 131                 {
 132                         SiteIdentityPermission sip = Cast (target);
 133                         if ((sip == null) || sip.IsEmpty ())
 134                                 return Copy ();
 135                         if (IsEmpty ())
 136                                 return sip.Copy ();
 137
 138                         if (Match (sip._site)) {
 139                                 string s = ((_site.Length < sip._site.Length) ? _site : sip._site);
 140                                 return new SiteIdentityPermission (s);
 141                         }
 142 #if NET_2_0
 143                         throw new ArgumentException (Locale.GetText (
 144                                 "Cannot union two different sites."), "target");
 145 #else
 146                         return null;
 147 #endif
 148                 }
 149
 150                 // IBuiltInPermission
 151                 int IBuiltInPermission.GetTokenIndex ()
 152                 {
 153                         return (int) BuiltInToken.SiteIdentity;
 154                 }
 155
 156                 // helpers
 157
 158                 private bool IsEmpty ()
 159                 {
 160                         return (_site == null);
 161                 }
 162
 163                 private SiteIdentityPermission Cast (IPermission target)
 164                 {
 165                         if (target == null)
 166                                 return null;
 167
 168                         SiteIdentityPermission sip = (target as SiteIdentityPermission);
 169                         if (sip == null) {
 170                                 ThrowInvalidPermission (target, typeof (SiteIdentityPermission));
 171                         }
 172
 173                         return sip;
 174                 }
 175
 176                 private static bool[] valid = new bool [94] {
 177                         /*  33 */ true,  false, true,  true,  true,  true,  true,  true,  true,  true,
 178                         /*  43 */ false, false, true,  true,  false, true,  true,  true,  true,  true,
 179                         /*  53 */ true,  true,  true,  true,  false, false, false, false, false, false,
 180                         /*  63 */ false, true,  true,  true,  true,  true,  true,  true,  true,  true,
 181                         /*  73 */ true,  true,  true,  true,  true,  true,  true,  true,  true,  true,
 182                         /*  83 */ true,  true,  true,  true,  true,  true,  true,  true,  false, false,
 183                         /*  93 */ false, true,  true,  false, true,  true,  true,  true,  true,  true,
 184                         /* 103 */ true,  true,  true,  true,  true,  true,  true,  true,  true,  true,
 185                         /* 113 */ true,  true,  true,  true,  true,  true,  true,  true,  true,  true,
 186                         /* 123 */ true,  false, true,  true
 187                 };
 188
 189                 private bool IsValid (string s)
 190                 {
 191                         if ((s == null) || (s.Length == 0))
 192                                 return false;
 193
 194                         for (int i = 0; i < s.Length; i++) {
 195                                 ushort x = (ushort) s [i];
 196                                 if ((x < 33) || (x > 126)) {
 197                                         return false;
 198                                 }
 199                                 if (x == 42) {
 200                                         // special case for wildcards (*)
 201                                         // must be alone or followed by a dot
 202                                         if ((s.Length > 1) && (s [i + 1] != '.'))
 203                                                 return false;
 204                                 }
 205                                 if (!valid [x - 33]) {
 206                                         return false;
 207                                 }
 208                         }
 209
 210                         // a lone dot isn't valid
 211                         if (s.Length == 1)
 212                                 return (s [0] != '.');
 213                         return true;
 214                 }
 215
 216                 private bool Match (string target)
 217                 {
 218                         if ((_site == null) || (target == null))
 219                                 return false;
 220
 221                         int wcs = _site.IndexOf ('*');
 222                         int wct = target.IndexOf ('*');
 223
 224                         if ((wcs == -1) && (wct == -1)) {
 225                                 // no wildcard, this is an exact match
 226                                 return (_site == target);
 227                         }
 228                         else if (wcs == -1) {
 229                                 // only "target" has a wildcard, use it
 230                                 return _site.EndsWith (target.Substring (wct + 1));
 231                         }
 232                         else if (wct == -1) {
 233                                 // only "this" has a wildcard, use it
 234                                 return target.EndsWith (_site.Substring (wcs + 1));
 235                         }
 236                         else {
 237                                 // both have wildcards, partial match with the smallest
 238                                 string s = _site.Substring (wcs + 1);
 239                                 target = target.Substring (wct + 1);
 240                                 if (s.Length > target.Length)
 241                                         return s.EndsWith (target);
 242                                 else
 243                                         return target.EndsWith (s);
 244                         }
 245                 }
 246         }
 247 }