class/corlib/System.Security.Cryptography/RC2.cs

   1 //
   2 // System.Security.Cryptography.RC2.cs
   3 //
   4 // Authors:
   5 //      Andrew Birkett (andy@nobugs.org)
   6 //      Sebastien Pouliot (sebastien@ximian.com)
   7 //
   8 // Copyright (C) 2004-2006 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.Runtime.InteropServices;
  31
  32 namespace System.Security.Cryptography {
  33
  34         // References:
  35         // a.   IETF RFC2286: A Description of the RC2(r) Encryption Algorithm
  36         //      http://www.ietf.org/rfc/rfc2268.txt
  37
  38         [ComVisible (true)]
  39         public abstract class RC2 : SymmetricAlgorithm {
  40
  41                 public static new RC2 Create ()
  42                 {
  43                         return Create ("System.Security.Cryptography.RC2");
  44                 }
  45
  46                 public static new RC2 Create (string AlgName)
  47                 {
  48                         return (RC2) CryptoConfig.CreateFromName (AlgName);
  49                 }
  50
  51                 protected int EffectiveKeySizeValue;
  52
  53                 public virtual int EffectiveKeySize {
  54                         get {
  55                                 if (EffectiveKeySizeValue == 0)
  56                                         return KeySizeValue;
  57                                 else
  58                                         return EffectiveKeySizeValue;
  59                         }
  60                         set {
  61                                 EffectiveKeySizeValue = value;
  62                         }
  63                 }
  64
  65                 public override int KeySize {
  66                         get { return base.KeySize; }
  67                         set {
  68                                 base.KeySize = value;
  69                                 EffectiveKeySizeValue = value;
  70                         }
  71                 }
  72
  73                 protected RC2 ()
  74                 {
  75                         KeySizeValue = 128;
  76                         BlockSizeValue = 64;
  77                         FeedbackSizeValue = 8;
  78
  79                         // The RFC allows keys of 1 to 128 bytes, but MS impl only supports
  80                         // 40 to 128 bits, sigh.
  81                         LegalKeySizesValue = new KeySizes [1];
  82                         LegalKeySizesValue [0] = new KeySizes (40, 128, 8);
  83
  84                         LegalBlockSizesValue = new KeySizes [1];
  85                         LegalBlockSizesValue [0] = new KeySizes (64, 64, 0);
  86                 }
  87         }
  88 }
  89