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

   1 //
   2 // System.Security.Permissions.EnvironmentPermission.cs
   3 //
   4 // Authors:
   5 //      Tim Coleman <tim@timcoleman.com>
   6 //      Sebastien Pouliot <spouliot@motus.com>
   7 //
   8 // Copyright (C) 2002, Tim Coleman
   9 // Portions Copyright (C) 2003 Motus Technologies (http://www.motus.com)
  10 //
  11
  12 using System;
  13 using System.Collections;
  14 using System.Security.Permissions;
  15 using System.Text;
  16
  17 namespace System.Security.Permissions {
  18
  19         [Serializable]
  20         public sealed class EnvironmentPermission : CodeAccessPermission, IUnrestrictedPermission, IBuiltInPermission {
  21
  22                 #region Fields
  23
  24                 EnvironmentPermissionAccess flags;
  25                 PermissionState _state;
  26                 ArrayList readList;
  27                 ArrayList writeList;
  28
  29                 #endregion // Fields
  30
  31                 #region Constructors
  32
  33                 public EnvironmentPermission (PermissionState state) : base ()
  34                 {
  35                         switch (state) {
  36                                 case PermissionState.None:
  37                                 case PermissionState.Unrestricted:
  38                                         _state = state;
  39                                         readList = new ArrayList ();
  40                                         writeList = new ArrayList ();
  41                                         break;
  42                                 default:
  43                                         throw new ArgumentException ("Invalid PermissionState", "state");
  44                         }
  45                 }
  46
  47                 public EnvironmentPermission (EnvironmentPermissionAccess flag, string pathList) : base ()
  48                 {
  49                         readList = new ArrayList ();
  50                         writeList = new ArrayList ();
  51                         SetPathList (flag, pathList);
  52                 }
  53
  54                 #endregion // Constructors
  55
  56                 #region Methods
  57
  58                 public void AddPathList (EnvironmentPermissionAccess flag, string pathList)
  59                 {
  60                         if (pathList == null)
  61                                 throw new ArgumentNullException ("pathList");
  62                         string[] paths;
  63                         switch (flag) {
  64                                 case EnvironmentPermissionAccess.AllAccess:
  65                                         paths = pathList.Split (';');
  66                                         foreach (string path in paths) {
  67                                                 if (!readList.Contains (path))
  68                                                         readList.Add (path);
  69                                                 if (!writeList.Contains (path))
  70                                                         writeList.Add (path);
  71                                         }
  72                                         break;
  73                                 case EnvironmentPermissionAccess.NoAccess:
  74                                         // ??? unit tests doesn't show removal using NoAccess ???
  75                                         break;
  76                                 case EnvironmentPermissionAccess.Read:
  77                                         paths = pathList.Split (';');
  78                                         foreach (string path in paths) {
  79                                                 if (!readList.Contains (path))
  80                                                         readList.Add (path);
  81                                         }
  82                                         break;
  83                                 case EnvironmentPermissionAccess.Write:
  84                                         paths = pathList.Split (';');
  85                                         foreach (string path in paths) {
  86                                                 if (!writeList.Contains (path))
  87                                                         writeList.Add (path);
  88                                         }
  89                                         break;
  90                                 default:
  91                                         throw new ArgumentException ("Invalid EnvironmentPermissionAccess", "flag");
  92                         }
  93                 }
  94
  95                 public override IPermission Copy ()
  96                 {
  97                         EnvironmentPermission ep = new EnvironmentPermission (_state);
  98                         string path = GetPathList (EnvironmentPermissionAccess.Read);
  99                         if (path != null)
 100                                 ep.SetPathList (EnvironmentPermissionAccess.Read, path);
 101                         path = GetPathList (EnvironmentPermissionAccess.Write);
 102                         if (path != null)
 103                                 ep.SetPathList (EnvironmentPermissionAccess.Write, path);
 104                         return ep;
 105                 }
 106
 107                 public override void FromXml (SecurityElement esd)
 108                 {
 109                         if (esd == null)
 110                                 throw new ArgumentNullException ("esd");
 111                         if (esd.Tag != "IPermission")
 112                                 throw new ArgumentException ("not IPermission");
 113                         if (!(esd.Attributes ["class"] as string).StartsWith ("System.Security.Permissions.EnvironmentPermission"))
 114                                 throw new ArgumentException ("not EnvironmentPermission");
 115                         if ((esd.Attributes ["version"] as string) != "1")
 116                                 throw new ArgumentException ("wrong version");
 117
 118                         string read = (esd.Attributes ["Read"] as string);
 119                         if ((read != null) && (read.Length > 0))
 120                                 SetPathList (EnvironmentPermissionAccess.Read, read);
 121                         string write = (esd.Attributes ["Write"] as string);
 122                         if ((write != null) && (write.Length > 0))
 123                                 SetPathList (EnvironmentPermissionAccess.Write, write);
 124
 125                         // Unrestricted ???
 126                 }
 127
 128                 public string GetPathList (EnvironmentPermissionAccess flag)
 129                 {
 130                         StringBuilder sb = new StringBuilder ();
 131                         switch (flag) {
 132                                 case EnvironmentPermissionAccess.AllAccess:
 133                                 case EnvironmentPermissionAccess.NoAccess:
 134                                         throw new ArgumentException ("Invalid EnvironmentPermissionAccess in context", "flag");
 135                                 case EnvironmentPermissionAccess.Read:
 136                                         foreach (string path in readList) {
 137                                                 sb.Append (path);
 138                                                 sb.Append (";");
 139                                         }
 140                                         break;
 141                                 case EnvironmentPermissionAccess.Write:
 142                                         foreach (string path in writeList) {
 143                                                 sb.Append (path);
 144                                                 sb.Append (";");
 145                                         }
 146                                         break;
 147                                 default:
 148                                         throw new ArgumentException ("Unknown EnvironmentPermissionAccess", "flag");
 149                         }
 150                         string result = sb.ToString ();
 151                         // remove last ';'
 152                         int n = result.Length;
 153                         if (n > 0)
 154                                 return result.Substring (0, n - 1);
 155                         return null;
 156                 }
 157
 158                 public override IPermission Intersect (IPermission target)
 159                 {
 160                         if (target == null)
 161                                 return null;
 162                         if (! (target is EnvironmentPermission))
 163                                 throw new ArgumentException ("wrong type");
 164
 165                         EnvironmentPermission o = (EnvironmentPermission) target;
 166                         int n = 0;
 167                         if (IsUnrestricted ())
 168                                 return o.Copy ();
 169                         if (o.IsUnrestricted ())
 170                                 return Copy ();
 171
 172                         EnvironmentPermission ep = new EnvironmentPermission (PermissionState.None);
 173                         string readTarget = o.GetPathList (EnvironmentPermissionAccess.Read);
 174                         if (readTarget != null) {
 175                                 string[] targets = readTarget.Split (';');
 176                                 foreach (string t in targets) {
 177                                         if (readList.Contains (t)) {
 178                                                 ep.AddPathList (EnvironmentPermissionAccess.Read, t);
 179                                                 n++;
 180                                         }
 181                                 }
 182                         }
 183
 184                         string writeTarget = o.GetPathList (EnvironmentPermissionAccess.Write);
 185                         if (writeTarget != null) {
 186                                 string[] targets = writeTarget.Split (';');
 187                                 foreach (string t in targets) {
 188                                         if (writeList.Contains (t)) {
 189                                                 ep.AddPathList (EnvironmentPermissionAccess.Write, t);
 190                                                 n++;
 191                                         }
 192                                 }
 193                         }
 194                         return ((n > 0) ? ep : null);
 195                 }
 196
 197                 public override bool IsSubsetOf (IPermission target)
 198                 {
 199                         if (target == null)
 200                                 return false;
 201
 202                         if (! (target is EnvironmentPermission))
 203                                 throw new ArgumentException ("wrong type");
 204
 205                         EnvironmentPermission o = (EnvironmentPermission) target;
 206                         if (IsUnrestricted ())
 207                                 return o.IsUnrestricted ();
 208                         else if (o.IsUnrestricted ())
 209                                 return true;
 210
 211                         foreach (string s in readList) {
 212                                 if (!o.readList.Contains (s))
 213                                         return false;
 214                         }
 215
 216                         foreach (string s in writeList) {
 217                                 if (!o.writeList.Contains (s))
 218                                         return false;
 219                         }
 220
 221                         return true;
 222                 }
 223
 224                 public bool IsUnrestricted ()
 225                 {
 226                         return (_state == PermissionState.Unrestricted);
 227                 }
 228
 229                 public void SetPathList (EnvironmentPermissionAccess flag, string pathList)
 230                 {
 231                         if (pathList == null)
 232                                 throw new ArgumentNullException ("pathList");
 233                         string[] paths;
 234                         switch (flag) {
 235                                 case EnvironmentPermissionAccess.AllAccess:
 236                                         readList.Clear ();
 237                                         writeList.Clear ();
 238                                         paths = pathList.Split (';');
 239                                         foreach (string path in paths) {
 240                                                 readList.Add (path);
 241                                                 writeList.Add (path);
 242                                         }
 243                                         break;
 244                                 case EnvironmentPermissionAccess.NoAccess:
 245                                         // ??? unit tests doesn't show removal using NoAccess ???
 246                                         break;
 247                                 case EnvironmentPermissionAccess.Read:
 248                                         readList.Clear ();
 249                                         paths = pathList.Split (';');
 250                                         foreach (string path in paths) {
 251                                                 readList.Add (path);
 252                                         }
 253                                         break;
 254                                 case EnvironmentPermissionAccess.Write:
 255                                         writeList.Clear ();
 256                                         paths = pathList.Split (';');
 257                                         foreach (string path in paths) {
 258                                                 writeList.Add (path);
 259                                         }
 260                                         break;
 261                                 default:
 262                                         throw new ArgumentException ("Invalid EnvironmentPermissionAccess", "flag");
 263                         }
 264                 }
 265
 266                 public override SecurityElement ToXml ()
 267                 {
 268                         SecurityElement se = Element (this, 1);
 269                         if (_state == PermissionState.Unrestricted) {
 270                                 se.AddAttribute ("Unrestricted", "true");
 271                         }
 272                         else {
 273                                 string path = GetPathList (EnvironmentPermissionAccess.Read);
 274                                 if (path != null)
 275                                         se.AddAttribute ("Read", path);
 276                                 path = GetPathList (EnvironmentPermissionAccess.Write);
 277                                 if (path != null)
 278                                         se.AddAttribute ("Write", path);
 279                         }
 280                         return se;
 281                 }
 282
 283                 public override IPermission Union (IPermission other)
 284                 {
 285                         if (other == null)
 286                                 return Copy ();
 287                         if (! (other is EnvironmentPermission))
 288                                 throw new ArgumentException ("wrong type");
 289
 290                         EnvironmentPermission o = (EnvironmentPermission) other;
 291                         if (IsUnrestricted () || o.IsUnrestricted ())
 292                                 return new EnvironmentPermission (PermissionState.Unrestricted);
 293
 294                         EnvironmentPermission ep = (EnvironmentPermission) Copy ();
 295                         string path = o.GetPathList (EnvironmentPermissionAccess.Read);
 296                         if (path != null)
 297                                 ep.AddPathList (EnvironmentPermissionAccess.Read, path);
 298                         path = o.GetPathList (EnvironmentPermissionAccess.Write);
 299                         if (path != null)
 300                                 ep.AddPathList (EnvironmentPermissionAccess.Write, path);
 301                         return ep;
 302                 }
 303
 304                 // IBuiltInPermission
 305                 int IBuiltInPermission.GetTokenIndex ()
 306                 {
 307                         return 0;
 308                 }
 309
 310                 #endregion // Methods
 311         }
 312 }