Unmodified KeepassLib from KeePass Desktop v2.20

src/KeePassLib2Android/Cryptography/Cipher/StandardAesEngine.cs

@@ -0,0 +1,140 @@
+/*
+  KeePass Password Safe - The Open-Source Password Manager
+  Copyright (C) 2003-2012 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.Text;
+using System.IO;
+using System.Security;
+using System.Security.Cryptography;
+using System.Diagnostics;
+
+using KeePassLib.Resources;
+
+namespace KeePassLib.Cryptography.Cipher
+{
+	/// <summary>
+	/// Standard AES cipher implementation.
+	/// </summary>
+	public sealed class StandardAesEngine : ICipherEngine
+	{
+		private const CipherMode m_rCipherMode = CipherMode.CBC;
+		private const PaddingMode m_rCipherPadding = PaddingMode.PKCS7;
+
+		private static PwUuid m_uuidAes = null;
+
+		/// <summary>
+		/// UUID of the cipher engine. This ID uniquely identifies the
+		/// AES engine. Must not be used by other ciphers.
+		/// </summary>
+		public static PwUuid AesUuid
+		{
+			get
+			{
+				if(m_uuidAes == null)
+				{
+					m_uuidAes = new PwUuid(new byte[]{
+						0x31, 0xC1, 0xF2, 0xE6, 0xBF, 0x71, 0x43, 0x50,
+						0xBE, 0x58, 0x05, 0x21, 0x6A, 0xFC, 0x5A, 0xFF });
+				}
+
+				return m_uuidAes;
+			}
+		}
+
+		/// <summary>
+		/// Get the UUID of this cipher engine as <c>PwUuid</c> object.
+		/// </summary>
+		public PwUuid CipherUuid
+		{
+			get { return StandardAesEngine.AesUuid; }
+		}
+
+		/// <summary>
+		/// Get a displayable name describing this cipher engine.
+		/// </summary>
+		public string DisplayName { get { return KLRes.EncAlgorithmAes; } }
+
+		private static void ValidateArguments(Stream stream, bool bEncrypt, byte[] pbKey, byte[] pbIV)
+		{
+			Debug.Assert(stream != null); if(stream == null) throw new ArgumentNullException("stream");
+
+			Debug.Assert(pbKey != null); if(pbKey == null) throw new ArgumentNullException("pbKey");
+			Debug.Assert(pbKey.Length == 32);
+			if(pbKey.Length != 32) throw new ArgumentException("Key must be 256 bits wide!");
+
+			Debug.Assert(pbIV != null); if(pbIV == null) throw new ArgumentNullException("pbIV");
+			Debug.Assert(pbIV.Length == 16);
+			if(pbIV.Length != 16) throw new ArgumentException("Initialization vector must be 128 bits wide!");
+
+			if(bEncrypt)
+			{
+				Debug.Assert(stream.CanWrite);
+				if(stream.CanWrite == false) throw new ArgumentException("Stream must be writable!");
+			}
+			else // Decrypt
+			{
+				Debug.Assert(stream.CanRead);
+				if(stream.CanRead == false) throw new ArgumentException("Encrypted stream must be readable!");
+			}
+		}
+
+		private static Stream CreateStream(Stream s, bool bEncrypt, byte[] pbKey, byte[] pbIV)
+		{
+			StandardAesEngine.ValidateArguments(s, bEncrypt, pbKey, pbIV);
+
+			RijndaelManaged r = new RijndaelManaged();
+
+			if(r.BlockSize != 128) // AES block size
+			{
+				Debug.Assert(false);
+				r.BlockSize = 128;
+			}
+
+			byte[] pbLocalIV = new byte[16];
+			Array.Copy(pbIV, pbLocalIV, 16);
+			r.IV = pbLocalIV;
+
+			byte[] pbLocalKey = new byte[32];
+			Array.Copy(pbKey, pbLocalKey, 32);
+			r.KeySize = 256;
+			r.Key = pbLocalKey;
+
+			r.Mode = m_rCipherMode;
+			r.Padding = m_rCipherPadding;
+
+			ICryptoTransform iTransform = (bEncrypt ? r.CreateEncryptor() : r.CreateDecryptor());
+			Debug.Assert(iTransform != null);
+			if(iTransform == null) throw new SecurityException("Unable to create Rijndael transform!");
+
+			return new CryptoStream(s, iTransform, bEncrypt ? CryptoStreamMode.Write :
+				CryptoStreamMode.Read);
+		}
+
+		public Stream EncryptStream(Stream sPlainText, byte[] pbKey, byte[] pbIV)
+		{
+			return StandardAesEngine.CreateStream(sPlainText, true, pbKey, pbIV);
+		}
+
+		public Stream DecryptStream(Stream sEncrypted, byte[] pbKey, byte[] pbIV)
+		{
+			return StandardAesEngine.CreateStream(sEncrypted, false, pbKey, pbIV);
+		}
+	}
+}