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 // (C) 2004 Novell (http://www.novell.com)
   9 //
  10
  11 using System;
  12
  13 namespace System.Security.Cryptography {
  14
  15         // References:
  16         // a.   IETF RFC2286: A Description of the RC2(r) Encryption Algorithm
  17         //      http://www.ietf.org/rfc/rfc2268.txt
  18
  19         public abstract class RC2 : SymmetricAlgorithm {
  20
  21                 public static new RC2 Create ()
  22                 {
  23                         return Create ("System.Security.Cryptography.RC2");
  24                 }
  25
  26                 public static new RC2 Create (string algName)
  27                 {
  28                         return (RC2) CryptoConfig.CreateFromName (algName);
  29                 }
  30
  31                 protected int EffectiveKeySizeValue;
  32
  33                 public virtual int EffectiveKeySize {
  34                         get {
  35                                 if (EffectiveKeySizeValue == 0)
  36                                         return KeySizeValue;
  37                                 else
  38                                         return EffectiveKeySizeValue;
  39                         }
  40                         set {
  41                                 EffectiveKeySizeValue = value;
  42                         }
  43                 }
  44
  45                 public override int KeySize {
  46                         get { return base.KeySize; }
  47                         set {
  48                                 base.KeySize = value;
  49                                 EffectiveKeySizeValue = value;
  50                         }
  51                 }
  52
  53                 public RC2 ()
  54                 {
  55                         KeySizeValue = 128;
  56                         BlockSizeValue = 64;
  57                         FeedbackSizeValue = 64;
  58
  59                         // The RFC allows keys of 1 to 128 bytes, but MS impl only supports
  60                         // 40 to 128 bits, sigh.
  61                         LegalKeySizesValue = new KeySizes [1];
  62                         LegalKeySizesValue [0] = new KeySizes (40, 128, 8);
  63
  64                         LegalBlockSizesValue = new KeySizes [1];
  65                         LegalBlockSizesValue [0] = new KeySizes (64, 64, 0);
  66                 }
  67         }
  68 }