// Default privacy provider (empty class).// Copyright (C) 2008-2010 Malcolm Crowe, Lex Li, and other contributors.// // 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;using System.Collections.Generic; namespace GSF.Net.Snmp.Security{    /// <summary>    /// Default privacy provider.    /// </summary>    public sealed class DefaultPrivacyProvider : IPrivacyProvider    {        private static IPrivacyProvider _defaultInstance;                /// <summary>        /// Default privacy provider with default authentication provider.        /// </summary>        public static IPrivacyProvider DefaultPair        {            get            {                return _defaultInstance ?? (_defaultInstance = new DefaultPrivacyProvider(DefaultAuthenticationProvider.Instance));            }        }                /// <summary>        /// Initializes a new instance of the <see cref="DefaultPrivacyProvider"/> class.        /// </summary>        /// <param name="authentication">Authentication provider.</param>        public DefaultPrivacyProvider(IAuthenticationProvider authentication)        {            AuthenticationProvider = authentication;        }         #region IPrivacyProvider Members         /// <summary>        /// Corresponding <see cref="IAuthenticationProvider"/>.        /// </summary>        public IAuthenticationProvider AuthenticationProvider { get; private set; }         [Obsolete("Use EngineIds instead.")]        public OctetString EngineId { get; set; }         /// <summary>        /// Engine IDs.        /// </summary>        /// <remarks>This is an optional field, and only used by TRAP v2 authentication.</remarks>        public ICollection<OctetString> EngineIds { get; set; }         /// <summary>        /// Decrypts the specified data.        /// </summary>        /// <param name="data">The data.</param>        /// <param name="parameters">The parameters.</param>        /// <returns></returns>        public ISnmpData Decrypt(ISnmpData data, SecurityParameters parameters)        {            if (data == null)            {                throw new ArgumentNullException(nameof(data));            }                        if (parameters == null)            {                throw new ArgumentNullException(nameof(parameters));            }                                    if (data.TypeCode != SnmpType.Sequence)            {                DecryptionException newException = new DecryptionException("Default decryption failed");                throw newException;            }                        return data;        }         /// <summary>        /// Encrypts the specified scope.        /// </summary>        /// <param name="data">The scope data.</param>        /// <param name="parameters">The parameters.</param>        /// <returns></returns>        public ISnmpData Encrypt(ISnmpData data, SecurityParameters parameters)        {            if (data == null)            {                throw new ArgumentNullException(nameof(data));            }                                    if (parameters == null)            {                throw new ArgumentNullException(nameof(parameters));            }                                  if (data.TypeCode == SnmpType.Sequence || data is ISnmpPdu)            {                return data;            }                        throw new ArgumentException("Invaild data type.", nameof(data));        }         /// <summary>        /// Gets the salt.        /// </summary>        /// <value>The salt.</value>        public OctetString Salt        {            get { return OctetString.Empty; }        }         /// <summary>        /// Passwords to key.        /// </summary>        /// <param name="secret">The secret.</param>        /// <param name="engineId">The engine identifier.</param>        /// <returns></returns>        public byte[] PasswordToKey(byte[] secret, byte[] engineId)        {            return AuthenticationProvider.PasswordToKey(secret, engineId);        }         #endregion         /// <summary>        /// Returns a <see cref="System.String"/> that represents this instance.        /// </summary>        /// <returns>        /// A <see cref="System.String"/> that represents this instance.        /// </returns>        public override string ToString()        {            return "Default privacy provider";        }    }}