//
// System.Security.Cryptography.HashAlgorithm.cs
//
// Authors:
// Matthew S. Ford (Matthew.S.Ford@Rose-Hulman.Edu)
// Sebastien Pouliot (sebastien@ximian.com)
//
// Copyright 2001 by Matthew S. Ford.
// Portions (C) 2002 Motus Technologies Inc. (http://www.motus.com)
// Copyright (C) 2004-2006 Novell, Inc (http://www.novell.com)
//
// Permission is hereby granted, free of charge, to any person obtaining
// a copy of this software and associated documentation files (the
// "Software"), to deal in the Software without restriction, including
// without limitation the rights to use, copy, modify, merge, publish,
// distribute, sublicense, and/or sell copies of the Software, and to
// permit persons to whom the Software is furnished to do so, subject to
// the following conditions:
//
// The above copyright notice and this permission notice shall be
// included in all copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
// EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
// MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
// NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
// LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
// OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
// WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
//
using System.Globalization;
using System.IO;
using System.Runtime.InteropServices;
namespace System.Security.Cryptography{
[ComVisible (true)]
public abstract class HashAlgorithm : ICryptoTransform {
protected internal byte[] HashValue;
protected int HashSizeValue;
protected int State;
private bool disposed;
protected HashAlgorithm ()
{
disposed = false;
}
public virtual bool CanTransformMultipleBlocks {
get { return true; }
}
public virtual bool CanReuseTransform {
get { return true; }
}
public void Clear ()
{
// same as System.IDisposable.Dispose() which is documented
Dispose (true);
}
public byte[] ComputeHash (byte[] buffer)
{
if (buffer == null)
throw new ArgumentNullException ("buffer");
return ComputeHash (buffer, 0, buffer.Length);
}
public byte[] ComputeHash (byte[] buffer, int offset, int count)
{
if (disposed)
throw new ObjectDisposedException ("HashAlgorithm");
if (buffer == null)
throw new ArgumentNullException ("buffer");
if (offset < 0)
throw new ArgumentOutOfRangeException ("offset", "< 0");
if (count < 0)
throw new ArgumentException ("count", "< 0");
// ordered to avoid possible integer overflow
if (offset > buffer.Length - count) {
throw new ArgumentException ("offset + count",
Locale.GetText ("Overflow"));
}
HashCore (buffer, offset, count);
HashValue = HashFinal ();
Initialize ();
return HashValue;
}
public byte[] ComputeHash (Stream inputStream)
{
// don't read stream unless object is ready to use
if (disposed)
throw new ObjectDisposedException ("HashAlgorithm");
byte[] buffer = new byte [4096];
int len = inputStream.Read (buffer, 0, 4096);
while (len > 0) {
HashCore (buffer, 0, len);
len = inputStream.Read (buffer, 0, 4096);
}
HashValue = HashFinal ();
Initialize ();
return HashValue;
}
public static HashAlgorithm Create ()
{
return Create ("System.Security.Cryptography.HashAlgorithm");
}
public static HashAlgorithm Create (string hashName)
{
return (HashAlgorithm) CryptoConfig.CreateFromName (hashName);
}
public virtual byte[] Hash {
get {
if (HashValue == null) {
throw new CryptographicUnexpectedOperationException (
Locale.GetText ("No hash value computed."));
}
return HashValue;
}
}
protected abstract void HashCore (byte[] array, int ibStart, int cbSize);
protected abstract byte[] HashFinal ();
public virtual int HashSize {
get { return HashSizeValue; }
}
public abstract void Initialize ();
protected virtual void Dispose (bool disposing)
{
disposed = true;
}
public virtual int InputBlockSize {
get { return 1; }
}
public virtual int OutputBlockSize {
get { return 1; }
}
void IDisposable.Dispose ()
{
Dispose (true);
GC.SuppressFinalize (this); // Finalization is now unnecessary
}
// LAMESPEC: outputBuffer is optional in 2.0 (i.e. can be null).
// However a null outputBuffer would throw a ExecutionEngineException under 1.x
public int TransformBlock (byte[] inputBuffer, int inputOffset, int inputCount, byte[] outputBuffer, int outputOffset)
{
if (inputBuffer == null)
throw new ArgumentNullException ("inputBuffer");
if (inputOffset < 0)
throw new ArgumentOutOfRangeException ("inputOffset", "< 0");
if (inputCount < 0)
throw new ArgumentException ("inputCount");
// ordered to avoid possible integer overflow
if ((inputOffset < 0) || (inputOffset > inputBuffer.Length - inputCount))
throw new ArgumentException ("inputBuffer");
if (outputBuffer != null) {
if (outputOffset < 0) {
throw new ArgumentOutOfRangeException ("outputOffset", "< 0");
}
// ordered to avoid possible integer overflow
if (outputOffset > outputBuffer.Length - inputCount) {
throw new ArgumentException ("outputOffset + inputCount",
Locale.GetText ("Overflow"));
}
}
HashCore (inputBuffer, inputOffset, inputCount);
if (outputBuffer != null)
Buffer.BlockCopy (inputBuffer, inputOffset, outputBuffer, outputOffset, inputCount);
return inputCount;
}
public byte[] TransformFinalBlock (byte[] inputBuffer, int inputOffset, int inputCount)
{
if (inputBuffer == null)
throw new ArgumentNullException ("inputBuffer");
if (inputCount < 0)
throw new ArgumentException ("inputCount");
// ordered to avoid possible integer overflow
if (inputOffset > inputBuffer.Length - inputCount) {
throw new ArgumentException ("inputOffset + inputCount",
Locale.GetText ("Overflow"));
}
byte[] outputBuffer = new byte [inputCount];
// note: other exceptions are handled by Buffer.BlockCopy
Buffer.BlockCopy (inputBuffer, inputOffset, outputBuffer, 0, inputCount);
HashCore (inputBuffer, inputOffset, inputCount);
HashValue = HashFinal ();
Initialize ();
return outputBuffer;
}
}
}
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