2 // TripleDESCryptoServiceProvider.cs: Default TripleDES implementation
5 // Sebastien Pouliot <sebastien@ximian.com>
7 // (C) 2002 Motus Technologies Inc. (http://www.motus.com)
8 // (C) 2004 Novell (http://www.novell.com)
12 using Mono.Security.Cryptography;
14 namespace System.Security.Cryptography {
17 // a. FIPS PUB 46-3: TripleDES
18 // http://csrc.nist.gov/publications/fips/fips46-3/fips46-3.pdf
21 // http://webstore.ansi.org/ansidocstore/product.asp?sku=ANSI+X9%2E52%2D1998
23 public sealed class TripleDESCryptoServiceProvider : TripleDES {
25 public TripleDESCryptoServiceProvider ()
29 public override void GenerateIV ()
31 IVValue = KeyBuilder.IV (BlockSizeValue >> 3);
34 public override void GenerateKey ()
36 KeyValue = KeyBuilder.Key (KeySizeValue >> 3);
39 public override ICryptoTransform CreateDecryptor (byte[] rgbKey, byte[] rgbIV)
43 return new TripleDESTransform (this, false, rgbKey, rgbIV);
46 public override ICryptoTransform CreateEncryptor (byte[] rgbKey, byte[] rgbIV)
50 return new TripleDESTransform (this, true, rgbKey, rgbIV);
54 // TripleDES is just DES-EDE
55 internal class TripleDESTransform : SymmetricTransform {
58 private DESTransform E1;
59 private DESTransform D2;
60 private DESTransform E3;
63 private DESTransform D1;
64 private DESTransform E2;
65 private DESTransform D3;
67 public TripleDESTransform (TripleDES algo, bool encryption, byte[] key, byte[] iv) : base (algo, encryption, iv)
69 byte[] key1 = new byte [8];
70 byte[] key2 = new byte [8];
71 byte[] key3 = new byte [8];
72 DES des = DES.Create ();
73 Buffer.BlockCopy (key, 0, key1, 0, 8);
74 Buffer.BlockCopy (key, 8, key2, 0, 8);
76 Buffer.BlockCopy (key, 0, key3, 0, 8);
78 Buffer.BlockCopy (key, 16, key3, 0, 8);
80 // note: some modes (like CFB) requires encryption when decrypting
81 if ((encryption) || (algo.Mode == CipherMode.CFB)) {
82 E1 = new DESTransform (des, true, key1, iv);
83 D2 = new DESTransform (des, false, key2, iv);
84 E3 = new DESTransform (des, true, key3, iv);
87 D1 = new DESTransform (des, false, key3, iv);
88 E2 = new DESTransform (des, true, key2, iv);
89 D3 = new DESTransform (des, false, key1, iv);
93 // note: this method is garanteed to be called with a valid blocksize
94 // for both input and output
95 protected override void ECB (byte[] input, byte[] output)
97 byte[] temp = new byte [input.Length];
99 E1.ProcessBlock (input, output);
100 D2.ProcessBlock (output, temp);
101 E3.ProcessBlock (temp, output);
104 D1.ProcessBlock (input, output);
105 E2.ProcessBlock (output, temp);
106 D3.ProcessBlock (temp, output);
107 // don't keep decrypted content in memory
108 Array.Clear (temp, 0, temp.Length);