148 lines
3.9 KiB
C#
148 lines
3.9 KiB
C#
//
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// Mono.Security.Cryptography.CryptoTools
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// Shared class for common cryptographic functionalities
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//
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// Authors:
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// Sebastien Pouliot <sebastien@ximian.com>
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//
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// (C) 2002, 2003 Motus Technologies Inc. (http://www.motus.com)
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// Copyright (C) 2004, 2008 Novell, Inc (http://www.novell.com)
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//
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// Permission is hereby granted, free of charge, to any person obtaining
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// a copy of this software and associated documentation files (the
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// "Software"), to deal in the Software without restriction, including
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// without limitation the rights to use, copy, modify, merge, publish,
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// distribute, sublicense, and/or sell copies of the Software, and to
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// permit persons to whom the Software is furnished to do so, subject to
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// the following conditions:
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//
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// The above copyright notice and this permission notice shall be
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// included in all copies or substantial portions of the Software.
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//
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// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
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// EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
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// MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
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// NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
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// LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
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// OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
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// WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
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//
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using System;
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using System.Security.Cryptography;
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namespace Mono.Security.Cryptography {
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#if INSIDE_CORLIB
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internal
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#else
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public
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#endif
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sealed class KeyBuilder {
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static private RandomNumberGenerator rng;
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private KeyBuilder ()
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{
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}
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static RandomNumberGenerator Rng {
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get {
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if (rng == null)
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rng = RandomNumberGenerator.Create ();
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return rng;
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}
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}
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static public byte[] Key (int size)
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{
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byte[] key = new byte [size];
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Rng.GetBytes (key);
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return key;
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}
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static public byte[] IV (int size)
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{
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byte[] iv = new byte [size];
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Rng.GetBytes (iv);
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return iv;
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}
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}
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// Process an array as a sequence of blocks
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#if INSIDE_CORLIB
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internal
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#else
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public
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#endif
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class BlockProcessor {
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private ICryptoTransform transform;
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private byte[] block;
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private int blockSize; // in bytes (not in bits)
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private int blockCount;
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public BlockProcessor (ICryptoTransform transform)
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: this (transform, transform.InputBlockSize) {}
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// some Transforms (like HashAlgorithm descendant) return 1 for
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// block size (which isn't their real internal block size)
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public BlockProcessor (ICryptoTransform transform, int blockSize)
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{
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if (transform == null)
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throw new ArgumentNullException ("transform");
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if (blockSize <= 0)
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throw new ArgumentOutOfRangeException ("blockSize");
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this.transform = transform;
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this.blockSize = blockSize;
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block = new byte [blockSize];
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}
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~BlockProcessor ()
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{
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// zeroize our block (so we don't retain any information)
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Array.Clear (block, 0, blockSize);
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}
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public void Initialize ()
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{
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Array.Clear (block, 0, blockSize);
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blockCount = 0;
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}
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public void Core (byte[] rgb)
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{
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Core (rgb, 0, rgb.Length);
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}
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public void Core (byte[] rgb, int ib, int cb)
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{
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// 1. fill the rest of the "block"
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int n = System.Math.Min (blockSize - blockCount, cb);
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Buffer.BlockCopy (rgb, ib, block, blockCount, n);
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blockCount += n;
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// 2. if block is full then transform it
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if (blockCount == blockSize) {
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transform.TransformBlock (block, 0, blockSize, block, 0);
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// 3. transform any other full block in specified buffer
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int b = (int) ((cb - n) / blockSize);
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for (int i=0; i < b; i++) {
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transform.TransformBlock (rgb, n + ib, blockSize, block, 0);
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n += blockSize;
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}
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// 4. if data is still present fill the "block" with the remainder
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blockCount = cb - n;
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if (blockCount > 0)
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Buffer.BlockCopy (rgb, n + ib, block, 0, blockCount);
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}
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}
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public byte[] Final ()
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{
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return transform.TransformFinalBlock (block, 0, blockCount);
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}
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}
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}
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