class/System/System.Net.Mail/SmtpPermission.cs

   1 //
   2 // System.Net.Mail.SmtpPermission
   3 //
   4 // Authors:
   5 //      Sebastien Pouliot  <sebastien@ximian.com>
   6 //
   7 // Copyright (C) 2006 Novell, Inc (http://www.novell.com)
   8 //
   9 // Permission is hereby granted, free of charge, to any person obtaining
  10 // a copy of this software and associated documentation files (the
  11 // "Software"), to deal in the Software without restriction, including
  12 // without limitation the rights to use, copy, modify, merge, publish,
  13 // distribute, sublicense, and/or sell copies of the Software, and to
  14 // permit persons to whom the Software is furnished to do so, subject to
  15 // the following conditions:
  16 //
  17 // The above copyright notice and this permission notice shall be
  18 // included in all copies or substantial portions of the Software.
  19 //
  20 // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
  21 // EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  22 // MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
  23 // NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
  24 // LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
  25 // OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
  26 // WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  27 //
  28
  29 #if NET_2_0
  30
  31 using System.Security;
  32 using System.Security.Permissions;
  33
  34 namespace System.Net.Mail {
  35
  36         [Serializable]
  37         public sealed class SmtpPermission : CodeAccessPermission, IUnrestrictedPermission {
  38
  39                 private const int version = 1;
  40
  41                 private bool unrestricted;
  42                 private SmtpAccess access;
  43
  44
  45                 public SmtpPermission (bool unrestricted)
  46                         : base ()
  47                 {
  48                         this.unrestricted = unrestricted;
  49                         access = unrestricted ? SmtpAccess.ConnectToUnrestrictedPort : SmtpAccess.None;
  50                 }
  51
  52                 public SmtpPermission (PermissionState state)
  53                         : base ()
  54                 {
  55                         unrestricted = (state == PermissionState.Unrestricted);
  56                         access =  unrestricted ? SmtpAccess.ConnectToUnrestrictedPort : SmtpAccess.None;
  57                 }
  58
  59                 public SmtpPermission (SmtpAccess access)
  60                         : base ()
  61                 {
  62                         // this ctor can accept invalid enum values
  63                         this.access = access;
  64                 }
  65
  66
  67                 public SmtpAccess Access {
  68                         get { return access; }
  69                 }
  70
  71
  72                 public void AddPermission (SmtpAccess access)
  73                 {
  74                         if (!unrestricted && (access > this.access)) {
  75                                 this.access = access;
  76                         }
  77                 }
  78
  79                 public override IPermission Copy ()
  80                 {
  81                         if (unrestricted) {
  82                                 return new SmtpPermission (true);
  83                         } else {
  84                                 return new SmtpPermission (access);
  85                         }
  86                 }
  87
  88                 public override IPermission Intersect (IPermission target)
  89                 {
  90                         SmtpPermission sp = Cast (target);
  91                         if (sp == null)
  92                                 return null;
  93
  94                         if (unrestricted && sp.unrestricted)
  95                                 return new SmtpPermission (true);
  96                         else if (access > sp.access)
  97                                 return new SmtpPermission (sp.access);
  98                         else
  99                                 return new SmtpPermission (access);
 100                 }
 101
 102                 public override bool IsSubsetOf (IPermission target)
 103                 {
 104                         SmtpPermission sp = Cast (target);
 105                         if (sp == null)
 106                                 return IsEmpty ();
 107
 108                         if (unrestricted) {
 109                                 return sp.unrestricted;
 110                         } else {
 111                                 return (access <= sp.access);
 112                         }
 113                 }
 114
 115                 public bool IsUnrestricted ()
 116                 {
 117                         return unrestricted;
 118                 }
 119
 120                 public override SecurityElement ToXml ()
 121                 {
 122                         SecurityElement se = PermissionHelper.Element (typeof (SmtpPermission), version);
 123                         if (unrestricted) {
 124                                 se.AddAttribute ("Unrestricted", "true");
 125                         } else {
 126                                 switch (access) {
 127                                 case SmtpAccess.ConnectToUnrestrictedPort:
 128                                         se.AddAttribute ("Access", "ConnectToUnrestrictedPort");
 129                                         break;
 130                                 case SmtpAccess.Connect:
 131                                         se.AddAttribute ("Access", "Connect");
 132                                         break;
 133                                 // note: SmtpAccess.None and invalid values aren't serialized to XML
 134                                 }
 135                         }
 136                         return se;
 137                 }
 138
 139                 public override void FromXml (SecurityElement securityElement)
 140                 {
 141                         PermissionHelper.CheckSecurityElement (securityElement, "securityElement", version, version);
 142
 143                         // LAMESPEC: it says to throw an ArgumentNullException in this case
 144                         if (securityElement.Tag != "IPermission")
 145                                 throw new ArgumentException ("securityElement");
 146
 147                         if (PermissionHelper.IsUnrestricted (securityElement))
 148                                 access = SmtpAccess.Connect;
 149                         else
 150                                 access = SmtpAccess.None;
 151                 }
 152
 153                 public override IPermission Union (IPermission target)
 154                 {
 155                         SmtpPermission sp = Cast (target);
 156                         if (sp == null)
 157                                 return Copy ();
 158
 159                         if (unrestricted || sp.unrestricted)
 160                                 return new SmtpPermission (true);
 161                         else if (access > sp.access)
 162                                 return new SmtpPermission (access);
 163                         else
 164                                 return new SmtpPermission (sp.access);
 165                 }
 166
 167                 // Internal helpers methods
 168
 169                 private bool IsEmpty ()
 170                 {
 171                         return (!unrestricted && (access == SmtpAccess.None));
 172                 }
 173
 174                 private SmtpPermission Cast (IPermission target)
 175                 {
 176                         if (target == null)
 177                                 return null;
 178
 179                         SmtpPermission sp = (target as SmtpPermission);
 180                         if (sp == null) {
 181                                 PermissionHelper.ThrowInvalidPermission (target, typeof (SmtpPermission));
 182                         }
 183
 184                         return sp;
 185                 }
 186         }
 187 }
 188
 189 #endif