2 // TripleDESCryptoServiceProvider.cs: Default TripleDES implementation
5 // Sebastien Pouliot (spouliot@motus.com)
7 // (C) 2002 Motus Technologies Inc. (http://www.motus.com)
11 using System.Security.Cryptography;
13 namespace System.Security.Cryptography {
16 // a. FIPS PUB 46-3: TripleDES
17 // http://csrc.nist.gov/publications/fips/fips46-3/fips46-3.pdf
20 // http://webstore.ansi.org/ansidocstore/product.asp?sku=ANSI+X9%2E52%2D1998
22 public class TripleDESCryptoServiceProvider : TripleDES {
24 public TripleDESCryptoServiceProvider ()
29 public override void GenerateIV ()
31 throw new System.NotImplementedException ();
35 public override void GenerateKey ()
37 KeyValue = new byte [KeySizeValue / 8];
40 public override ICryptoTransform CreateDecryptor (byte[] rgbKey, byte[] rgbIV)
44 return new TripleDESTransform (this, false, rgbKey, rgbIV);
47 public override ICryptoTransform CreateEncryptor (byte[] rgbKey, byte[] rgbIV)
51 return new TripleDESTransform (this, true, rgbKey, rgbIV);
55 // TripleDES is just DES-EDE
56 internal class TripleDESTransform : SymmetricTransform {
59 private DESTransform E1;
60 private DESTransform D2;
61 private DESTransform E3;
64 private DESTransform D1;
65 private DESTransform E2;
66 private DESTransform D3;
68 public TripleDESTransform (TripleDES algo, bool encryption, byte[] key, byte[] iv) : base (algo, encryption, iv)
70 byte[] key1 = new byte [8];
71 byte[] key2 = new byte [8];
72 byte[] key3 = new byte [8];
73 DES des = DES.Create ();
74 Array.Copy (key, 0, key1, 0, 8);
75 Array.Copy (key, 8, key2, 0, 8);
77 Array.Copy (key, 0, key3, 0, 8);
79 Array.Copy (key, 16, key3, 0, 8);
81 // note: some modes (like CFB) requires encryption when decrypting
82 if ((encryption) || (algo.Mode == CipherMode.CFB)) {
83 E1 = new DESTransform (des, true, key1, iv);
84 D2 = new DESTransform (des, false, key2, iv);
85 E3 = new DESTransform (des, true, key3, iv);
88 D1 = new DESTransform (des, false, key3, iv);
89 E2 = new DESTransform (des, true, key2, iv);
90 D3 = new DESTransform (des, false, key1, iv);
94 // note: this method is garanteed to be called with a valid blocksize
95 // for both input and output
96 protected override void ECB (byte[] input, byte[] output)
98 byte[] temp = new byte [input.Length];
100 E1.ProcessBlock (input, output);
101 D2.ProcessBlock (output, temp);
102 E3.ProcessBlock (temp, output);
105 D1.ProcessBlock (input, output);
106 E2.ProcessBlock (output, temp);
107 D3.ProcessBlock (temp, output);