mcs/class/corlib/System.Security.Policy/PolicyStatement.cs

   1 //\r
   2 // System.Security.Policy.PolicyStatement.cs\r
   3 //\r
   4 // Authors:\r
   5 //      Dan Lewis (dihlewis@yahoo.co.uk)\r
   6 //      Sebastien Pouliot  <sebastien@ximian.com>
   7 //\r
   8 // (C) 2002\r
   9 // Copyright (C) 2004-2005 Novell, Inc (http://www.novell.com)
  10 //
  11 // Permission is hereby granted, free of charge, to any person obtaining
  12 // a copy of this software and associated documentation files (the
  13 // "Software"), to deal in the Software without restriction, including
  14 // without limitation the rights to use, copy, modify, merge, publish,
  15 // distribute, sublicense, and/or sell copies of the Software, and to
  16 // permit persons to whom the Software is furnished to do so, subject to
  17 // the following conditions:
  18 //
  19 // The above copyright notice and this permission notice shall be
  20 // included in all copies or substantial portions of the Software.
  21 //
  22 // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
  23 // EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  24 // MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
  25 // NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
  26 // LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
  27 // OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
  28 // WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  29 //
  30 \r
  31 using System.Runtime.InteropServices;
  32 using System.Security.Permissions;\r
  33 \r
  34 namespace System.Security.Policy {\r
  35 \r
  36         [Serializable]\r
  37         [ComVisible (true)]
  38         public sealed class PolicyStatement : ISecurityEncodable, ISecurityPolicyEncodable {
  39
  40                 private PermissionSet perms;\r
  41                 private PolicyStatementAttribute attrs;\r
  42 \r
  43                 public PolicyStatement (PermissionSet permSet) :
  44                         this (permSet, PolicyStatementAttribute.Nothing)\r
  45                 {
  46                 }\r
  47 \r
  48                 public PolicyStatement (PermissionSet permSet, PolicyStatementAttribute attributes)
  49                 {\r
  50                         if (permSet != null) {\r
  51                                 this.perms = permSet.Copy ();
  52                                 this.perms.SetReadOnly (true);
  53                         }\r
  54                         this.attrs = attributes;\r
  55                 }\r
  56                 \r
  57                 public PermissionSet PermissionSet {\r
  58                         get {
  59                                 if (perms == null) {
  60                                         perms = new PermissionSet (PermissionState.None);
  61                                         perms.SetReadOnly (true);
  62                                 }
  63                                 return perms;
  64                         }\r
  65                         set { perms = value; }\r
  66                 }\r
  67                 \r
  68                 public PolicyStatementAttribute Attributes {\r
  69                         get { return attrs; }\r
  70                         set {
  71                                 // note: yes it's a flag but all possible values have a corresponding name
  72                                 switch (value) {
  73                                 case PolicyStatementAttribute.Nothing:
  74                                 case PolicyStatementAttribute.Exclusive:
  75                                 case PolicyStatementAttribute.LevelFinal:
  76                                 case PolicyStatementAttribute.All:
  77                                         attrs = value;
  78                                         break;
  79                                 default:
  80                                         string msg = Locale.GetText ("Invalid value for {0}.");
  81                                         throw new ArgumentException (String.Format (msg, "PolicyStatementAttribute"));
  82                                 }
  83                         }\r
  84                 }\r
  85 \r
  86                 public string AttributeString {\r
  87                         get {
  88                                 switch (attrs) {
  89                                 case PolicyStatementAttribute.Exclusive:
  90                                         return "Exclusive";
  91                                 case PolicyStatementAttribute.LevelFinal:
  92                                         return "LevelFinal";
  93                                 case PolicyStatementAttribute.All:
  94                                         return "Exclusive LevelFinal";
  95                                 default:
  96                                         return String.Empty;
  97                                 }
  98                         }\r
  99                 }\r
 100 \r
 101                 public PolicyStatement Copy ()\r
 102                 {\r
 103                         return new PolicyStatement (perms, attrs);\r
 104                 }\r
 105 \r
 106                 // ISecurityEncodable\r
 107 \r
 108                 public void FromXml (SecurityElement et)\r
 109                 {\r
 110                         FromXml (et, null);\r
 111                 }\r
 112 \r
 113                 public void FromXml (SecurityElement et, PolicyLevel level)\r
 114                 {
 115                         if (et == null)
 116                                 throw new ArgumentNullException ("et");
 117                         if (et.Tag != "PolicyStatement")
 118                                 throw new ArgumentException (Locale.GetText ("Invalid tag."));
 119 \r
 120 \r
 121                         string attributes = et.Attribute ("Attributes");\r
 122                         if (attributes != null) {\r
 123                                 attrs = (PolicyStatementAttribute) Enum.Parse (\r
 124                                         typeof (PolicyStatementAttribute), attributes);\r
 125                         }
 126 \r
 127                         SecurityElement permissions = et.SearchForChildByTag ("PermissionSet");\r
 128                         PermissionSet.FromXml (permissions);\r
 129                 }\r
 130                 \r
 131                 public SecurityElement ToXml ()\r
 132                 {\r
 133                         return ToXml (null);\r
 134                 }\r
 135 \r
 136                 public SecurityElement ToXml (PolicyLevel level)\r
 137                 {\r
 138                         SecurityElement element = new SecurityElement ("PolicyStatement");\r
 139                         element.AddAttribute ("version", "1");\r
 140 \r
 141                         if (attrs != PolicyStatementAttribute.Nothing)\r
 142                                 element.AddAttribute ("Attributes", attrs.ToString ());\r
 143                         \r
 144                         element.AddChild (PermissionSet.ToXml ());\r
 145 \r
 146                         return element;\r
 147                 }
 148
 149                 [ComVisible (false)]
 150                 public override bool Equals (object obj)
 151                 {
 152                         if (obj == null)
 153                                 return false;
 154                         PolicyStatement ps = (obj as PolicyStatement);
 155                         if (ps == null)
 156                                 return false;
 157
 158                         return (PermissionSet.Equals (obj) && (attrs == ps.attrs));
 159                 }
 160
 161                 [ComVisible (false)]
 162                 public override int GetHashCode ()
 163                 {
 164                         // return same hash code if two PolicyStatement are equals
 165                         return (PermissionSet.GetHashCode () ^ (int) attrs);
 166                 }
 167
 168                 internal static PolicyStatement Empty ()
 169                 {
 170                         return new PolicyStatement (new PermissionSet (PermissionState.None));
 171                 }
 172         }\r
 173 }\r