mcs/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) 2004-2005 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 #if NET_2_0
  39         [ComVisible (true)]
  40 #endif
  41         public abstract class RC2 : SymmetricAlgorithm {
  42
  43                 public static new RC2 Create ()
  44                 {
  45                         return Create ("System.Security.Cryptography.RC2");
  46                 }
  47
  48                 public static new RC2 Create (string algName)
  49                 {
  50                         return (RC2) CryptoConfig.CreateFromName (algName);
  51                 }
  52
  53                 protected int EffectiveKeySizeValue;
  54
  55                 public virtual int EffectiveKeySize {
  56                         get {
  57                                 if (EffectiveKeySizeValue == 0)
  58                                         return KeySizeValue;
  59                                 else
  60                                         return EffectiveKeySizeValue;
  61                         }
  62                         set {
  63                                 EffectiveKeySizeValue = value;
  64                         }
  65                 }
  66
  67                 public override int KeySize {
  68                         get { return base.KeySize; }
  69                         set {
  70                                 base.KeySize = value;
  71                                 EffectiveKeySizeValue = value;
  72                         }
  73                 }
  74
  75                 public RC2 ()
  76                 {
  77                         KeySizeValue = 128;
  78                         BlockSizeValue = 64;
  79                         FeedbackSizeValue = 8;
  80
  81                         // The RFC allows keys of 1 to 128 bytes, but MS impl only supports
  82                         // 40 to 128 bits, sigh.
  83                         LegalKeySizesValue = new KeySizes [1];
  84                         LegalKeySizesValue [0] = new KeySizes (40, 128, 8);
  85
  86                         LegalBlockSizesValue = new KeySizes [1];
  87                         LegalBlockSizesValue [0] = new KeySizes (64, 64, 0);
  88                 }
  89         }
  90 }