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

   1 //
   2 // MACTripleDES.cs: Handles MAC with TripleDES
   3 //
   4 // Author:
   5 //      Sebastien Pouliot (sebastien@ximian.com)
   6 //
   7 // (C) 2002, 2003 Motus Technologies Inc. (http://www.motus.com)
   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 #if !MOONLIGHT
  31
  32 using System.Runtime.InteropServices;
  33
  34 using Mono.Security.Cryptography;
  35
  36 namespace System.Security.Cryptography {
  37
  38         // References:
  39         // a.   FIPS PUB 81: DES MODES OF OPERATION
  40         //      MAC: Appendix F (MACDES not MACTripleDES but close enough ;-)
  41         //      http://www.itl.nist.gov/fipspubs/fip81.htm
  42
  43         // LAMESPEC: MACTripleDES == MAC-CBC using TripleDES (not MAC-CFB).
  44         [ComVisible (true)]
  45         public class MACTripleDES: KeyedHashAlgorithm {
  46
  47                 private TripleDES tdes;
  48                 private MACAlgorithm mac;
  49                 private bool m_disposed;
  50
  51                 public MACTripleDES ()
  52                 {
  53                         Setup ("TripleDES", null);
  54                 }
  55
  56                 public MACTripleDES (byte[] rgbKey)
  57                 {
  58                         if (rgbKey == null)
  59                                 throw new ArgumentNullException ("rgbKey");
  60                         Setup ("TripleDES", rgbKey);
  61                 }
  62
  63                 public MACTripleDES (string strTripleDES, byte[] rgbKey)
  64                 {
  65                         if (rgbKey == null)
  66                                 throw new ArgumentNullException ("rgbKey");
  67                         if (strTripleDES == null)
  68                                 Setup ("TripleDES", rgbKey);
  69                         else
  70                                 Setup (strTripleDES, rgbKey);
  71                 }
  72
  73                 private void Setup (string strTripleDES, byte[] rgbKey)
  74                 {
  75                         tdes = TripleDES.Create (strTripleDES);
  76                         // default padding (as using in Fx 1.0 and 1.1)
  77                         tdes.Padding = PaddingMode.Zeros;
  78                         // if rgbKey is null we keep the randomly generated key
  79                         if (rgbKey != null) {
  80                                 // this way we get the TripleDES key validation (like weak
  81                                 // and semi-weak keys)
  82                                 tdes.Key = rgbKey;
  83                         }
  84                         HashSizeValue = tdes.BlockSize;
  85                         // we use Key property to get the additional validations
  86                         // (from KeyedHashAlgorithm ancestor)
  87                         Key = tdes.Key;
  88                         mac = new MACAlgorithm (tdes);
  89                         m_disposed = false;
  90                 }
  91
  92                 ~MACTripleDES ()
  93                 {
  94                         Dispose (false);
  95                 }
  96
  97                 [ComVisible (false)]
  98                 public PaddingMode Padding {
  99                         get { return tdes.Padding; }
 100                         set { tdes.Padding = value; }
 101                 }
 102
 103                 protected override void Dispose (bool disposing)
 104                 {
 105                         if (!m_disposed) {
 106                                 // note: we ALWAYS zeroize keys (disposing or not)
 107
 108                                 // clear our copy of the secret key
 109                                 if (KeyValue != null)
 110                                         Array.Clear (KeyValue, 0, KeyValue.Length);
 111                                 // clear the secret key (inside TripleDES)
 112                                 if (tdes != null)
 113                                         tdes.Clear ();
 114
 115                                 if (disposing) {
 116                                         // disposed managed stuff
 117                                         KeyValue = null;
 118                                         tdes = null;
 119                                 }
 120                                 // ancestor
 121                                 base.Dispose (disposing);
 122                                 m_disposed = true;
 123                         }
 124                 }
 125
 126                 public override void Initialize ()
 127                 {
 128                         if (m_disposed)
 129                                 throw new ObjectDisposedException ("MACTripleDES");
 130                         State = 0;
 131                         mac.Initialize (KeyValue);
 132                 }
 133
 134                 protected override void HashCore (byte[] rgbData, int ibStart, int cbSize)
 135                 {
 136                         if (m_disposed)
 137                                 throw new ObjectDisposedException ("MACTripleDES");
 138                         if (State == 0) {
 139                                 Initialize ();
 140                                 State = 1;
 141                         }
 142                         mac.Core (rgbData, ibStart, cbSize);
 143                 }
 144
 145                 protected override byte[] HashFinal ()
 146                 {
 147                         if (m_disposed)
 148                                 throw new ObjectDisposedException ("MACTripleDES");
 149                         State = 0;
 150                         return mac.Final ();
 151                 }
 152         }
 153 }
 154
 155 #endif
 156