Setup solution

ModernKeePassLib/Cryptography/Cipher/CipherPool.cs

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+/*
+  KeePass Password Safe - The Open-Source Password Manager
+  Copyright (C) 2003-2019 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;
+
+namespace ModernKeePassLib.Cryptography.Cipher
+{
+	/// <summary>
+	/// Pool of encryption/decryption algorithms (ciphers).
+	/// </summary>
+	public sealed class CipherPool
+	{
+		private List<ICipherEngine> m_lCiphers = new List<ICipherEngine>();
+
+		private static CipherPool m_poolGlobal = null;
+		public static CipherPool GlobalPool
+		{
+			get
+			{
+				CipherPool cp = m_poolGlobal;
+				if(cp == null)
+				{
+					cp = new CipherPool();
+					cp.AddCipher(new StandardAesEngine());
+					cp.AddCipher(new ChaCha20Engine());
+
+					m_poolGlobal = cp;
+				}
+
+				return cp;
+			}
+		}
+
+		/// <summary>
+		/// Remove all cipher engines from the current pool.
+		/// </summary>
+		public void Clear()
+		{
+			m_lCiphers.Clear();
+		}
+
+		/// <summary>
+		/// Add a cipher engine to the pool.
+		/// </summary>
+		/// <param name="c">Cipher engine to add. Must not be <c>null</c>.</param>
+		public void AddCipher(ICipherEngine c)
+		{
+			if(c == null) { Debug.Assert(false); throw new ArgumentNullException("c"); }
+
+			// Return if a cipher with that ID is registered already
+			foreach(ICipherEngine cEx in m_lCiphers)
+			{
+				if(cEx.CipherUuid.Equals(c.CipherUuid))
+					return;
+			}
+
+			m_lCiphers.Add(c);
+		}
+
+		/// <summary>
+		/// Get a cipher identified by its UUID.
+		/// </summary>
+		/// <param name="uuidCipher">UUID of the cipher to return.</param>
+		/// <returns>Reference to the requested cipher. If the cipher is
+		/// not found, <c>null</c> is returned.</returns>
+		public ICipherEngine GetCipher(PwUuid uuidCipher)
+		{
+			foreach(ICipherEngine c in m_lCiphers)
+			{
+				if(c.CipherUuid.Equals(uuidCipher))
+					return c;
+			}
+
+			return null;
+		}
+
+		/// <summary>
+		/// Get the index of a cipher. This index is temporary and should
+		/// not be stored or used to identify a cipher.
+		/// </summary>
+		/// <param name="uuidCipher">UUID of the cipher.</param>
+		/// <returns>Index of the requested cipher. Returns <c>-1</c> if
+		/// the specified cipher is not found.</returns>
+		public int GetCipherIndex(PwUuid uuidCipher)
+		{
+			for(int i = 0; i < m_lCiphers.Count; ++i)
+			{
+				if(m_lCiphers[i].CipherUuid.Equals(uuidCipher))
+					return i;
+			}
+
+			Debug.Assert(false);
+			return -1;
+		}
+
+		/// <summary>
+		/// Get the index of a cipher. This index is temporary and should
+		/// not be stored or used to identify a cipher.
+		/// </summary>
+		/// <param name="strDisplayName">Name of the cipher. Note that
+		/// multiple ciphers can have the same name. In this case, the
+		/// first matching cipher is returned.</param>
+		/// <returns>Cipher with the specified name or <c>-1</c> if
+		/// no cipher with that name is found.</returns>
+		public int GetCipherIndex(string strDisplayName)
+		{
+			for(int i = 0; i < m_lCiphers.Count; ++i)
+			{
+				if(m_lCiphers[i].DisplayName == strDisplayName)
+					return i;
+			}
+
+			Debug.Assert(false);
+			return -1;
+		}
+
+		/// <summary>
+		/// Get the number of cipher engines in this pool.
+		/// </summary>
+		public int EngineCount
+		{
+			get { return m_lCiphers.Count; }
+		}
+
+		/// <summary>
+		/// Get the cipher engine at the specified position. Throws
+		/// an exception if the index is invalid. You can use this
+		/// to iterate over all ciphers, but do not use it to
+		/// identify ciphers.
+		/// </summary>
+		/// <param name="nIndex">Index of the requested cipher engine.</param>
+		/// <returns>Reference to the cipher engine at the specified
+		/// position.</returns>
+		public ICipherEngine this[int nIndex]
+		{
+			get
+			{
+				if((nIndex < 0) || (nIndex >= m_lCiphers.Count))
+					throw new ArgumentOutOfRangeException("nIndex");
+
+				return m_lCiphers[nIndex];
+			}
+		}
+	}
+}