2 // MACTripleDES.cs: Handles MAC with TripleDES
5 // Sebastien Pouliot <sebastien@xamarin.com>
7 // (C) 2002, 2003 Motus Technologies Inc. (http://www.motus.com)
8 // Copyright (C) 2004-2005 Novell, Inc (http://www.novell.com)
9 // Copyright 2013 Xamarin Inc. (http://www.xamarin.com)
11 // Permission is hereby granted, free of charge, to any person obtaining
12 // a copy of this software and associated documentation files (the
13 // "Software"), to deal in the Software without restriction, including
14 // without limitation the rights to use, copy, modify, merge, publish,
15 // distribute, sublicense, and/or sell copies of the Software, and to
16 // permit persons to whom the Software is furnished to do so, subject to
17 // the following conditions:
19 // The above copyright notice and this permission notice shall be
20 // included in all copies or substantial portions of the Software.
22 // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
23 // EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
24 // MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
25 // NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
26 // LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
27 // OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
28 // WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
31 using System.Runtime.InteropServices;
33 using Mono.Security.Cryptography;
35 namespace System.Security.Cryptography {
38 // a. FIPS PUB 81: DES MODES OF OPERATION
39 // MAC: Appendix F (MACDES not MACTripleDES but close enough ;-)
40 // http://www.itl.nist.gov/fipspubs/fip81.htm
42 // LAMESPEC: MACTripleDES == MAC-CBC using TripleDES (not MAC-CFB).
44 public class MACTripleDES: KeyedHashAlgorithm {
46 private TripleDES tdes;
47 private MACAlgorithm mac;
48 private bool m_disposed;
50 public MACTripleDES ()
55 public MACTripleDES (byte[] rgbKey)
58 throw new ArgumentNullException ("rgbKey");
62 public MACTripleDES (string strTripleDES, byte[] rgbKey)
65 throw new ArgumentNullException ("rgbKey");
66 if (strTripleDES == null)
69 Setup (TripleDES.Create (strTripleDES), rgbKey);
72 private void Setup (TripleDES tripleDES, byte[] rgbKey)
74 tdes = tripleDES ?? TripleDES.Create ();
75 // default padding (as using in Fx 1.0 and 1.1)
76 tdes.Padding = PaddingMode.Zeros;
77 // if rgbKey is null we keep the randomly generated key
79 // this way we get the TripleDES key validation (like weak
80 // and semi-weak keys)
83 HashSizeValue = tdes.BlockSize;
84 // we use Key property to get the additional validations
85 // (from KeyedHashAlgorithm ancestor)
87 mac = new MACAlgorithm (tdes);
92 public PaddingMode Padding {
93 get { return tdes.Padding; }
94 set { tdes.Padding = value; }
97 protected override void Dispose (bool disposing)
100 // note: we ALWAYS zeroize keys (disposing or not)
102 // clear our copy of the secret key
103 if (KeyValue != null)
104 Array.Clear (KeyValue, 0, KeyValue.Length);
105 // clear the secret key (inside TripleDES)
110 // disposed managed stuff
115 base.Dispose (disposing);
120 public override void Initialize ()
123 throw new ObjectDisposedException ("MACTripleDES");
125 mac.Initialize (KeyValue);
128 protected override void HashCore (byte[] rgbData, int ibStart, int cbSize)
131 throw new ObjectDisposedException ("MACTripleDES");
136 mac.Core (rgbData, ibStart, cbSize);
139 protected override byte[] HashFinal ()
142 throw new ObjectDisposedException ("MACTripleDES");