2 // Mono.Security.Cryptography.CryptoTools
3 // Shared class for common cryptographic functionalities
6 // Sebastien Pouliot <sebastien@ximian.com>
8 // (C) 2002, 2003 Motus Technologies Inc. (http://www.motus.com)
9 // Copyright (C) 2004, 2008 Novell, Inc (http://www.novell.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.
32 using System
.Security
.Cryptography
;
34 namespace Mono
.Security
.Cryptography
{
41 sealed class KeyBuilder
{
43 static private RandomNumberGenerator rng
;
49 static RandomNumberGenerator Rng
{
51 #if NET_2_1 && !MONOTOUCH
53 rng
= new RNGCryptoServiceProvider ();
56 rng
= RandomNumberGenerator
.Create ();
62 static public byte[] Key (int size
)
64 byte[] key
= new byte [size
];
69 static public byte[] IV (int size
)
71 byte[] iv
= new byte [size
];
77 // Process an array as a sequence of blocks
83 class BlockProcessor
{
84 private ICryptoTransform transform
;
86 private int blockSize
; // in bytes (not in bits)
87 private int blockCount
;
89 public BlockProcessor (ICryptoTransform transform
)
90 : this (transform
, transform
.InputBlockSize
) {}
92 // some Transforms (like HashAlgorithm descendant) return 1 for
93 // block size (which isn't their real internal block size)
94 public BlockProcessor (ICryptoTransform transform
, int blockSize
)
96 this.transform
= transform
;
97 this.blockSize
= blockSize
;
98 block
= new byte [blockSize
];
103 // zeroize our block (so we don't retain any information)
104 Array
.Clear (block
, 0, blockSize
);
107 public void Initialize ()
109 Array
.Clear (block
, 0, blockSize
);
113 public void Core (byte[] rgb
)
115 Core (rgb
, 0, rgb
.Length
);
118 public void Core (byte[] rgb
, int ib
, int cb
)
120 // 1. fill the rest of the "block"
121 int n
= System
.Math
.Min (blockSize
- blockCount
, cb
);
122 Buffer
.BlockCopy (rgb
, ib
, block
, blockCount
, n
);
125 // 2. if block is full then transform it
126 if (blockCount
== blockSize
) {
127 transform
.TransformBlock (block
, 0, blockSize
, block
, 0);
129 // 3. transform any other full block in specified buffer
130 int b
= (int) ((cb
- n
) / blockSize
);
131 for (int i
=0; i
< b
; i
++) {
132 transform
.TransformBlock (rgb
, n
+ ib
, blockSize
, block
, 0);
136 // 4. if data is still present fill the "block" with the remainder
139 Buffer
.BlockCopy (rgb
, n
+ ib
, block
, 0, blockCount
);
143 public byte[] Final ()
145 return transform
.TransformFinalBlock (block
, 0, blockCount
);