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

   1 //
   2 // System.Security.Cryptography KeySizes Class implementation
   3 //
   4 // Authors:
   5 //      Matthew S. Ford (Matthew.S.Ford@Rose-Hulman.Edu)
   6 //      Ben Maurer (bmaurer@users.sf.net)
   7 //      Sebastien Pouliot (sebastien@ximian.com)
   8 //
   9 // Copyright 2001 by Matthew S. Ford.
  10 // Copyright (C) 2004-2005 Novell, Inc (http://www.novell.com)
  11 //
  12 // Permission is hereby granted, free of charge, to any person obtaining
  13 // a copy of this software and associated documentation files (the
  14 // "Software"), to deal in the Software without restriction, including
  15 // without limitation the rights to use, copy, modify, merge, publish,
  16 // distribute, sublicense, and/or sell copies of the Software, and to
  17 // permit persons to whom the Software is furnished to do so, subject to
  18 // the following conditions:
  19 //
  20 // The above copyright notice and this permission notice shall be
  21 // included in all copies or substantial portions of the Software.
  22 //
  23 // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
  24 // EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  25 // MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
  26 // NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
  27 // LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
  28 // OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
  29 // WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  30 //
  31
  32 using System.Runtime.InteropServices;
  33
  34 namespace System.Security.Cryptography {
  35
  36 #if !NET_2_1
  37         [ComVisible (true)]
  38 #endif
  39         public sealed class KeySizes {
  40                 private int _maxSize;
  41                 private int _minSize;
  42                 private int _skipSize;
  43
  44                 public KeySizes (int minSize, int maxSize, int skipSize)
  45                 {
  46                         _maxSize = maxSize;
  47                         _minSize = minSize;
  48                         _skipSize = skipSize;
  49                 }
  50
  51                 public int MaxSize {
  52                         get { return _maxSize; }
  53                 }
  54
  55                 public int MinSize {
  56                         get { return _minSize; }
  57                 }
  58
  59                 public int SkipSize {
  60                         get { return _skipSize; }
  61                 }
  62
  63                 internal bool IsLegal (int keySize)
  64                 {
  65                         int ks = keySize - MinSize;
  66                         bool result = ((ks >= 0) && (keySize <= MaxSize));
  67                         return ((SkipSize == 0) ? result : (result && (ks % SkipSize == 0)));
  68                 }
  69
  70                 internal static bool IsLegalKeySize (KeySizes[] legalKeys, int size)
  71                 {
  72                         foreach (KeySizes legalKeySize in legalKeys) {
  73                                 if (legalKeySize.IsLegal (size))
  74                                         return true;
  75                         }
  76                         return false;
  77                 }
  78         }
  79 }