127 lines
3.3 KiB
C#
127 lines
3.3 KiB
C#
/*
|
|
KeePass Password Safe - The Open-Source Password Manager
|
|
Copyright (C) 2003-2016 Dominik Reichl <dominik.reichl@t-online.de>
|
|
|
|
This program is free software; you can redistribute it and/or modify
|
|
it under the terms of the GNU General Public License as published by
|
|
the Free Software Foundation; either version 2 of the License, or
|
|
(at your option) any later version.
|
|
|
|
This program is distributed in the hope that it will be useful,
|
|
but WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
|
GNU General Public License for more details.
|
|
|
|
You should have received a copy of the GNU General Public License
|
|
along with this program; if not, write to the Free Software
|
|
Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
|
|
*/
|
|
|
|
using System;
|
|
using System.Collections.Generic;
|
|
using System.Diagnostics;
|
|
using System.Security.Cryptography;
|
|
using System.Text;
|
|
|
|
using KeePassLib.Utility;
|
|
|
|
namespace KeePassLib.Cryptography
|
|
{
|
|
public static class CryptoUtil
|
|
{
|
|
public static byte[] HashSha256(byte[] pbData)
|
|
{
|
|
if(pbData == null) throw new ArgumentNullException("pbData");
|
|
|
|
return HashSha256(pbData, 0, pbData.Length);
|
|
}
|
|
|
|
public static byte[] HashSha256(byte[] pbData, int iOffset, int cbCount)
|
|
{
|
|
if(pbData == null) throw new ArgumentNullException("pbData");
|
|
|
|
#if DEBUG
|
|
byte[] pbCopy = new byte[pbData.Length];
|
|
Array.Copy(pbData, pbCopy, pbData.Length);
|
|
#endif
|
|
|
|
byte[] pbHash;
|
|
using(SHA256Managed h = new SHA256Managed())
|
|
{
|
|
pbHash = h.ComputeHash(pbData, iOffset, cbCount);
|
|
}
|
|
|
|
#if DEBUG
|
|
// Ensure the data has not been modified
|
|
Debug.Assert(MemUtil.ArraysEqual(pbData, pbCopy));
|
|
|
|
Debug.Assert((pbHash != null) && (pbHash.Length == 32));
|
|
byte[] pbZero = new byte[32];
|
|
Debug.Assert(!MemUtil.ArraysEqual(pbHash, pbZero));
|
|
#endif
|
|
|
|
return pbHash;
|
|
}
|
|
|
|
/// <summary>
|
|
/// Create a cryptographic key of length <paramref name="cbOut" />
|
|
/// (in bytes) from <paramref name="pbIn" />.
|
|
/// </summary>
|
|
public static byte[] ResizeKey(byte[] pbIn, int iInOffset,
|
|
int cbIn, int cbOut)
|
|
{
|
|
if(pbIn == null) throw new ArgumentNullException("pbIn");
|
|
if(cbOut < 0) throw new ArgumentOutOfRangeException("cbOut");
|
|
|
|
if(cbOut == 0) return MemUtil.EmptyByteArray;
|
|
|
|
byte[] pbHash;
|
|
if(cbOut <= 32) pbHash = HashSha256(pbIn, iInOffset, cbIn);
|
|
else
|
|
{
|
|
using(SHA512Managed h = new SHA512Managed())
|
|
{
|
|
pbHash = h.ComputeHash(pbIn, iInOffset, cbIn);
|
|
}
|
|
}
|
|
|
|
if(cbOut == pbHash.Length) return pbHash;
|
|
|
|
byte[] pbRet = new byte[cbOut];
|
|
if(cbOut < pbHash.Length)
|
|
Array.Copy(pbHash, pbRet, cbOut);
|
|
else
|
|
{
|
|
int iPos = 0;
|
|
ulong r = 0;
|
|
while(iPos < cbOut)
|
|
{
|
|
Debug.Assert(pbHash.Length == 64);
|
|
using(HMACSHA256 h = new HMACSHA256(pbHash))
|
|
{
|
|
byte[] pbR = MemUtil.UInt64ToBytes(r);
|
|
byte[] pbPart = h.ComputeHash(pbR);
|
|
|
|
int cbCopy = Math.Min(cbOut - iPos, pbPart.Length);
|
|
Debug.Assert(cbCopy > 0);
|
|
|
|
Array.Copy(pbPart, 0, pbRet, iPos, cbCopy);
|
|
iPos += cbCopy;
|
|
++r;
|
|
|
|
MemUtil.ZeroByteArray(pbPart);
|
|
}
|
|
}
|
|
Debug.Assert(iPos == cbOut);
|
|
}
|
|
|
|
#if DEBUG
|
|
byte[] pbZero = new byte[pbHash.Length];
|
|
Debug.Assert(!MemUtil.ArraysEqual(pbHash, pbZero));
|
|
#endif
|
|
MemUtil.ZeroByteArray(pbHash);
|
|
return pbRet;
|
|
}
|
|
}
|
|
}
|