WIP Update lib to 2.37

ModernKeePassLib/Cryptography/Cipher/ChaCha20Engine.cs

@@ -0,0 +1,177 @@
+/*
+  KeePass Password Safe - The Open-Source Password Manager
+  Copyright (C) 2003-2017 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.IO;
+using System.Text;
+
+using ModernKeePassLib.Resources;
+
+namespace ModernKeePassLib.Cryptography.Cipher
+{
+	public sealed class ChaCha20Engine : ICipherEngine2
+	{
+		private PwUuid m_uuid = new PwUuid(new byte[] {
+			0xD6, 0x03, 0x8A, 0x2B, 0x8B, 0x6F, 0x4C, 0xB5,
+			0xA5, 0x24, 0x33, 0x9A, 0x31, 0xDB, 0xB5, 0x9A
+		});
+
+		public PwUuid CipherUuid
+		{
+			get { return m_uuid; }
+		}
+
+		public string DisplayName
+		{
+			get
+			{
+				return ("ChaCha20 (" + KLRes.KeyBits.Replace(@"{PARAM}",
+					"256") + ", RFC 7539)");
+			}
+		}
+
+		public int KeyLength
+		{
+			get { return 32; }
+		}
+
+		public int IVLength
+		{
+			get { return 12; } // 96 bits
+		}
+
+		public Stream EncryptStream(Stream sPlainText, byte[] pbKey, byte[] pbIV)
+		{
+			return new ChaCha20Stream(sPlainText, true, pbKey, pbIV);
+		}
+
+		public Stream DecryptStream(Stream sEncrypted, byte[] pbKey, byte[] pbIV)
+		{
+			return new ChaCha20Stream(sEncrypted, false, pbKey, pbIV);
+		}
+	}
+
+	internal sealed class ChaCha20Stream : Stream
+	{
+		private Stream m_sBase;
+		private readonly bool m_bWriting;
+		private ChaCha20Cipher m_c;
+
+		private byte[] m_pbBuffer = null;
+
+		public override bool CanRead
+		{
+			get { return !m_bWriting; }
+		}
+
+		public override bool CanSeek
+		{
+			get { return false; }
+		}
+
+		public override bool CanWrite
+		{
+			get { return m_bWriting; }
+		}
+
+		public override long Length
+		{
+			get { Debug.Assert(false); throw new NotSupportedException(); }
+		}
+
+		public override long Position
+		{
+			get { Debug.Assert(false); throw new NotSupportedException(); }
+			set { Debug.Assert(false); throw new NotSupportedException(); }
+		}
+
+		public ChaCha20Stream(Stream sBase, bool bWriting, byte[] pbKey32,
+			byte[] pbIV12)
+		{
+			if(sBase == null) throw new ArgumentNullException("sBase");
+
+			m_sBase = sBase;
+			m_bWriting = bWriting;
+			m_c = new ChaCha20Cipher(pbKey32, pbIV12);
+		}
+
+		protected override void Dispose(bool bDisposing)
+		{
+			if(bDisposing)
+			{
+				if(m_sBase != null)
+				{
+					m_c.Dispose();
+					m_c = null;
+
+					//m_sBase.Close();
+					m_sBase = null;
+				}
+
+				m_pbBuffer = null;
+			}
+
+			base.Dispose(bDisposing);
+		}
+
+		public override void Flush()
+		{
+			Debug.Assert(m_sBase != null);
+			if(m_bWriting && (m_sBase != null)) m_sBase.Flush();
+		}
+
+		public override long Seek(long lOffset, SeekOrigin soOrigin)
+		{
+			Debug.Assert(false);
+			throw new NotImplementedException();
+		}
+
+		public override void SetLength(long lValue)
+		{
+			Debug.Assert(false);
+			throw new NotImplementedException();
+		}
+
+		public override int Read(byte[] pbBuffer, int iOffset, int nCount)
+		{
+			if(m_bWriting) throw new InvalidOperationException();
+
+			int cbRead = m_sBase.Read(pbBuffer, iOffset, nCount);
+			m_c.Decrypt(pbBuffer, iOffset, cbRead);
+			return cbRead;
+		}
+
+		public override void Write(byte[] pbBuffer, int iOffset, int nCount)
+		{
+			if(nCount < 0) throw new ArgumentOutOfRangeException("nCount");
+			if(nCount == 0) return;
+
+			if(!m_bWriting) throw new InvalidOperationException();
+
+			if((m_pbBuffer == null) || (m_pbBuffer.Length < nCount))
+				m_pbBuffer = new byte[nCount];
+			Array.Copy(pbBuffer, iOffset, m_pbBuffer, 0, nCount);
+
+			m_c.Encrypt(m_pbBuffer, 0, nCount);
+			m_sBase.Write(m_pbBuffer, 0, nCount);
+		}
+	}
+}